Iron(III) and iron(II) complexes of 1-thia-4,7-diazacyclononane ([9]aneN(2)S) and 1,4-dithia-7-azacyclononane ([9]aneNS(2)). X-Ray structural analyses, magnetic susceptibility, Mossbauer, EPR and electronic spectroscopy

The complexes [Fe([9]aneN(2)S)(2)][ClO4](2), [Fe([9]aneN(2)S)(2)][ClO4](3) and [Fe([9]aneNS(2))(2)][ClO4](2) ([9]aneN(2)S = 1-thia-4. 7-diazacyclononane and [9]aneNS(2) = 1,4-dithia-7-azacyclononane) have been prepared and the latter two characterised by X-ray crystallography. The Mossbauer spectra (isomer shift/mm s(-1), quadrupole splitting/mm s(-1), 4.2 K) for [Fe([9]aneN(2)S)(2)][ClO4](2) (0.52, 0.57), [Fe([9]aneN(2)S)(2)][ClO4](3) (0.25, 2.72) and [Fe([9]aneNS(2))(2)][ClO4](2) (0.43, 0.28) are typical for iron(II) and iron(III) complexes. Variable-temperature susceptibility measurements for [Fe([9]aneN(2)S)(2)][ClO4](2) (2-300 K) revealed temperature-dependent behaviour in both the solid state [2.95 mu(B) (300 K)-0.5 mu(B) (4.2 K)] and solution (Delta H degrees 20-22 kJ mol(-1), Delta S degrees 53-60 J mol(-1) K-1). For [Fe([9]aneN(2)S)(2)][ClO4](3) in the solid state [2.3 mu(B) (300 K)-1.9 mu(B) (4.2 K)] the magnetic data were fit to a simple model (H = -lambda L . S + mu L-z) to give the spin-orbit coupling constant (lambda) of -260 +/- 10 cm(-1). The solid-state X-band EPR spectrum of [Fe([9]aneN(2)S)(2)][ClO4](3) revealed axial symmetry (g(perpendicular to) = 2.607, g(parallel to) = 1.599). Resolution of g(perpendicular to) into two components at Q-band frequencies indicated a rhombic distortion. The low-temperature single-crystal absorption spectra of [Fe([9]aneN(2)S)(2)][ClO4](2) and [Fe([9]aneNS(2))(2)][ClO4](2) exhibited additional bands which resembled pseudotetragonal low-symmetry splitting of the parent octahedral (1)A(1g) --> T-1(2g) and (1)A(1g) ---> T-1(1g) transitions. However, the magnitude of these splittings was too large, requiring 10Dq for the thioether donors to be significantly larger than for the amine donors. Instead, these bands were tentatively assigned to weak, low-energy S --> Fe-II charge-transfer transitions. Above 200 K, thermal occupation of the high-spin T-5(2g) ground state resulted in observation of the T-5(2g) --> E-5(g) transition in the crystal spectrum of [Fe([9]aneN(2)S)(2)][ClO4](2). From a temperature-dependence study, the separation of the low-spin (1)A(1g) and high-spin T-5(2g) ground states was approximately 1700 cm(-1). The spectrum of the iron(III) complex [Fe([9]aneN(2)S)(2)][ClO4](3) is consistent with a low-spin d(5) configuration.

A promoter from sugarcane bacilliform badnavirus drives transgene expression in banana and other monocot and dicot plants

A 1369 bp DNA fragment (Sc) was isolated from a full-length clone of sugarcane bacilliform badnavirus (ScBV) and was shown to have promoter activity in transient expression assays using monocot (banana, maize, millet and sorghum) and dicot plant species (tobacco, sunflower, canola and Nicotiana benthamiana). This promoter was also tested for stable expression in transgenic banana and tobacco plants. These experiments showed that this promoter could drive high-level expression of the beta-glucuronidase (GUS) reporter gene in most plant cells. The expression level was comparable to the maize ubiquitin promoter in standardised transient assays in maize. In transgenic banana plants the expression levels were variable for different transgenic lines but was generally comparable with the activities of both the maize ubiquitin promoter and the enhanced cauliflower mosaic virus (CaMV) 35S promoter. The Sc promoter appears to express in a near-constitutive manner in transgenic banana and tobacco plants. The promoter from sugarcane bacilliform virus represents a useful tool for the high-level expression of foreign genes in both monocot and dicot transgenic plants that could be used similarly to the CaMV 35S or maize polyubiquitin promoter.

Crystal and molecular structure of 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone (NIH) and its iron(III) complex: an iron chelator with anti-tumour activity

Previous studies have demonstrated that 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone (NIH) and several other aroylhydrazone chelators possess anti-neoplastic activity due to their ability to bind intracellular iron. In this study we have examined the structure and properties of NIH and its Fe-III complex in order to obtain further insight into its anti-tumour activity. Two tridentate NIH ligands deprotonate upon coordination to Fe-III in a meridional fashion to form a distorted octahedral, high-spin complex. Solution electrochemistry of [Fe(NIH-H)(2)](+) shows that the trivalent oxidation state is dominant over a wide potential range and that the Fe-II analogue is not a stable form of this complex. The fact that [Fe(NIH-H)(2)](+) cannot-cycle between the Fe-II and Fe-III states suggests that the production of toxic free- radical species, e.g. OH. or O2(.-),is not part of this ligand's cytotoxic action. This suggestion is supported by cell culture experiments demonstrating that the addition of Fe-III to NIH prevents its anti-proliferative effect. The chemistry of this chelator and its Fe-III complex are discussed in the context of understanding its anti-tumour activity.

Analysis of long-term light-trap data for Helicoverpa spp. (Lepidoptera : Noctuidae) in Australia: the effect of climate and crop host plants

Regression analyses of a long series of light-trap catches at Narrabri, Australia, were used to describe the seasonal dynamics of Helicoverpa armigera (Hubner). The size of the second generation was significantly related to the size of the first generation, to winter rainfall, which had a positive effect, and to spring rainfall which had a negative effect. These variables accounted for up to 96% of the variation in size of the second generation from year to year. Rainfall and crop hosts were also important for the size of the third generation. The area and tonnage of many potential host crops were significantly correlated with winter rain. When winter rain was omitted from the analysis, the sizes of both the second and third generations could be expressed as a function of the size of the previous generation and of the areas planted to lucerne, sorghum and maize. Lucerne and maize always had positive coefficients and sorghum a negative one. We extended our analysis to catches of H. punctigera (Wallengren), which declines in abundance after the second generation. Winter rain had a positive effect on the sizes of the second and third generations, and rain in spring or early summer had a negative effect. Only the area grown to lucerne had a positive effect on abundance. Forecasts of pest levels from a few months to a few weeks in advance are discussed, along with the improved understanding of the seasonal dynamics of both species and the significance of crops in the management of insecticide resistance for H. armigera.

The biologically active iron chelators 2-pyridylcarboxaldehyde isonicotinoylhydrazone, 2-pyridylcarboxaldehyde benzoylhydrazone monohydrate and 2-furaldehyde isonicotinoylhydrazone

In the crystal structures of the respective title compounds, C12H10N4O, C13H11N3O . H2O and C11K9N3O2, variations in the torsion angles of the aromatic pyridyl and benzoyl groups are observed, and the disposition of the heterocyclic aldehyde is shown to be influenced by the ring size of this group.

A protocol for the fluorometric quantification of mGFP5-ER and sGFP(S65T) in transgenic plants

The Green Fluorescent Protein (GFP) from Aequorea victor-in has begun to be used as a reporter protein in plants. It is particularly useful as GFP fluorescence can be detected in a non-destructive manner, whereas detection of enzyme-based reporters often requires destruction of the plant tissue. The use of GFP as a reporter enables transgenic plant tissues to be screened in vivo at any growth stage. Quantification of GFP in transgenic plant extracts will increase the utility of GFP as a reporter protein. We report herein the quantification of a mGFP5-ER Variant in tobacco leaf extracts by UV excitation and a sGFP(S65T) variant in sugarcane leaf and callus extracts by blue light excitation using the BioRad VersaFluor(TM) Fluorometer System or the Labsystems Fluoroskan Ascent FL equipped with a narrow band emission filter (510 +/- 5 nm). The GFP concentration in transgenic plant extracts was determined from a GFP-standard series prepared in untransformed plant extract with concentrations ranging from 0.1 to 4 mu g/ml of purified rGFP. Levels of sgfp(S65T) expression, driven by the maize ubiquitin promoter, in sugarcane calli and leaves ranged up to 0.525 mu g and 2.11 mu g sGFP(S65T) per mg of extractable protein respectively. In tobacco leaves the expression of mgfPS-ER, driven by the cauliflower mosaic virus (CaMV) 35S promoter, ranged up to 7.05 mu g mGFP5-ER per mg extractable protein.

Decentralized control design for nonlinear plants: a v-metric approach

In this paper, a new v-metric based approach is proposed to design decentralized controllers for multi-unit nonlinear plants that admit a set of plant decompositions in an operating space. Similar to the gap metric approach in literature, it is shown that the operating space can also be divided into several subregions based on a v-metric indicator, and each of the subregions admits the same controller structure. A comparative case study is presented to display the advantages of proposed approach over the gap metric approach. (C) 2000 Elsevier Science Ltd. All rights reserved.

Iron deficiency, general health and fatigue: Results from the Australian Longitudinal Study on Women's Health

Associations between self-reported 'low iron', general health and well-being, vitality and tiredness in women, were examined using physical (PCS) and mental (MCS) component summary and vitality (VT) scores from the MOS short-form survey (SF-36). 14,762 young (18-23 years) and 14,072 mid-age (45-50 years) women, randomly selected from the national health insurance commission (Medicare) database, completed a baseline mailed self-report questionnaire and 12,328 mid-age women completed a follow-up questionnaire 2 years later. Young and mid-age women who reported (ever) having had 'low iron' reported significantly lower mean PCS, MCS and VT scores, and greater prevalence of 'constant tiredness' at baseline than women with no history of iron deficiency [Differences: young PCS = -2.2, MCS = -4.8, VT = -8.7; constant tiredness: 67% vs. 45%; mid-age PCS = -1.4, MCS = -3.1, VT = -5.9; constant tiredness: 63% vs. 48%]. After adjusting for number of children, chronic conditions, symptoms and socio-demographic variables, mean PCS, MCS and VT scores for mid-age women at follow-up were significantly lower for women who reported recent iron deficiency (in the last 2 years) than for women who reported past iron deficiency or no history of iron deficiency [Means: PCS - recent = 46.6, past = 47.8, never = 47.7; MCS - recent = 45.4, past = 46.9, never = 47.4; VT - recent = 54.8, past = 57.6, never = 58.6]. The adjusted mean change in PCS, MCS and VT scores between baseline and follow-up were also significantly lower among mid-age women who reported iron deficiency only in the last 2 years (i.e. recent iron deficiency) [Mean change: PCS = -3.2; MCS = -2.1; VT = -4.2]. The results suggest that iron deficiency is associated with decreased general health and well-being and increased fatigue.

Experimental study of phase equilibria in the systems Fe-Zn-O and Fe-Zn-Si-O at metallic iron saturation

The reported experimental work on the systems Fe-Zn-O and Fe-Zn-Si-O in equilibrium with metallic iron is part of a wider research program that combines experimental and thermodynamic computer modeling techniques to characterize zinc/lead industrial slags and sinters in the system PbO-ZnO-SiO2-CaO-FeO-Fe2O3. Extensive experimental,investigations using high-temperature equilibration and quenching techniques followed by electron probe X-ray microanalysis (EPMA) were carried out. Special experimental; procedures were developed to enable accurate measurements in these ZnO-containing systems to be performed in equilibrium with metallic iron; The systems Fe-Zn-O and FeZn-Si-O were experimentally investigated in equilibrium with metallic iron in the temperature ranges 900 degreesC to 1200 degreesC (1173 to 1473 K) and from 1000 degreesC to 1350 degreesC (1273 to 1623 K), respectively. The liquidus surface in the system Fe-Zn-Si-O in equilibrium with metallic iron was characterized in the composition ranges 0 to 33 wt pet ZnO and 0 to 40 wt pet SiO2. The wustite (Fe,Zn)O, zincite (Zn,Fe)O, willemite (Zn,Fe)(2)SiO4, arid fayalite: (Fe,Zn)(2)SiO4 solid solutions in equilibrium with metallic iron were measured.

Circular proteins in plants - Solution structure of a novel macrocyclic trypsin inhibitor from Momordica cochinchinensis

Much interest has been generated by recent reports on the discovery of circular (i.e. head-to-tail cyclized) proteins in plants. Here we report the three-dimensional structure of one of the newest such circular proteins, MCoTI-II, a novel trypsin inhibitor from Momordica cochinchinensis, a member of the Cucurbitaceae plant family. The structure consists of a small beta -sheet, several turns, and a cystine knot arrangement of the three disulfide bonds. Interestingly, the molecular topology is similar to that of the plant cyclotides (Craik, D. J., Daly, N. L., Bond, T., and Waine, C. (1999) J. Mol. Biol, 294, 1327-1336), which derive from the Rubiaceae and Violaceae plant families, have antimicrobial activities, and exemplify the cyclic cystine knot structural motif as part of their circular backbone. The sequence, biological activity, and plant family of MCoTI-II are all different from known cyclotides. However, given the structural similarity, cyclic backbone, and plant origin of MCoTI-II, we propose that MCoTI-II can be classified as a new member of the cyclotide class of proteins. The expansion of the cyclotides to include trypsin inhibitory activity and a new plant family highlights the importance and functional variability of circular proteins and the fact that they are more common than has previously been believed, Insights into the possible roles of backbone cyclization have been gained by a comparison of the structure of MCoTI-II with the homologous acyclic trypsin inhibitors CMTI-I and EETI-II from the Cucurbitaceae plant family.

L-studio/cpfg: A software system for modeling plants

L-studio/cpfg is a plant modeling software system designed for Windows 95/98/NT platforms. Its key components are the L-system-based plant simulator cpfg and the modeling environment called L-studio. We overview version 1.0 of this system from the user's perspective.

Using biplots to interpret gene expression patterns in plants

Sum: Plant biologists in fields of ecology, evolution, genetics and breeding frequently use multivariate methods. This paper illustrates Principal Component Analysis (PCA) and Gabriel's biplot as applied to microarray expression data from plant pathology experiments. Availability: An example program in the publicly distributed statistical language R is available from the web site (www.tpp.uq.edu.au) and by e-mail from the contact. Contact: scott.chapman@csiro.au.

Experimental study of phase equilibria in the "FeO"-ZnO-(CaO+SiO2) system with CaO/SiO2 weight ratios of 0.33, 0.93, and 1.2 in equilibrium with metallic iron

The pseudoternary sections FeO-ZnO-(CaO + SiO2) with CaO/SiO2 weight ratios of 0.33, 0.93, and 1.2 in equilibrium with metallic iron have been experimentally investigated in the temperature range from 1000 degreesC to 1300 degreesC (1273 to 1573 K). The liquidus surfaces in these pseudoternary sections have been experimentally determined in the composition range from 0 to 33 wt pct ZnO and 30 to 70 wt pct (CaO + SiO2). The sections contain primary-phase fields of wustite (FexZn1-xO1+y), zincite (ZnzFe1-zO), fayalite (Fu(w)Zn(2-w)SiO(4)), melilite (Ca2ZnuFe1-uSi2O7), willemite (ZnvFe2-vSiO4), dicalcium silicate (Ca2SiO4), pseudowollastonite and wollastonite (CaSiO3), and tridymite (SiO2). The phase equilibria involving the liquid phase and the solid solutions-have also been measured.