Achievements in forest tree genetic improvement in Australia and New Zealand 2: Development of Corymbia species and hybrids for plantations in eastern Australia

This paper describes the establishment of provenance seedling seed orchards of three spotted gums and cadaga (all species of Corymbia ex Eucalyptus). It also discusses the limitations of growing the spotted gums as pure species including: lack of mass flowering, susceptibility to a fungal shoot blight and low amenability to vegetative propagation. These limitations, together with observation of putative natural hybrids of the spotted gums with cadaga, and the early promise of manipulated hybrids, led to an intensive breeding and testing program. Many hybrid families have significant advantages in growth and tolerance to disease, insects and frost, and can be vegetatively propagated. They also exhibit broad environmental plasticity, allowing the best varieties to be planted across a wider range of sites than the spotted gums, resulting in more land being suitable for plantation development.

Screening selected myrtaceous tree species for production of essential oils in northern Queensland

Trials to identify alternative cropping options to Melaleuca alternifolia for northern Queensland essential oil growers were established at Dimbulah and Innot Hot Springs in 2001. Seed sources of Asteromyrtus symphyocarpa (1,8-cineole form), Eucalyptus staigeriana (citral), Melaleuca cajuputi subsp. cajuputi (trans-nerolidol), M. ericifolia (d-linalool), M. quinquenervia (trans-nerolidol and viridiflorol forms) and M. viridiflora (methyl cinnamate) with potential to produce commercial foliar oils were evaluated. Information was gathered on their adaptability, growth and oil yields over 49 months and 52 months (two harvests) from planting at Dimbulah and Innot Hot Springs, respectively. Of the species and chemotypes evaluated, M. quinquenervia showed potential for commercial production of trans-nerolidol, a compound used in perfumery. It had a very high survival rate (96%) and yields could be expected to improve dramatically from the average 100 kg/ha per harvest achieved in these trials with further research into selection of seed source, control of insect damage and breeding for genetic improvement. M. cajuputi subsp. cajuputi gave a similar performance to M. quinquenervia. The rarity of the trans-nerolidol form of this species and remoteness of its natural occurrence are impediments to further planting and research. E. staigeriana, with second harvest yields of ~600 kg/ha, performed exceptionally well on both sites but potential for development is limited by the ready availability of competitively priced E. staigeriana oil produced in South America. Survival of M. ericifolia ranged from 62% to 82% at 32 months (second harvest) at Innot Hot Springs and was deemed a failure at Dimbulah with poor growth and low survival, raising a major question about the suitability of this species for cultivation in the seasonally dry tropics. Planting of this species on a wider scale in northern Queensland cannot be recommended until more is known about factors affecting its survival. A. symphyocarpa and M. viridiflora were too slow-growing to warrant further consideration as potential oil-producing species at this time.

A novel Z-structure for poly d(GC).poly d(GC)

A novel zig-zag (Z) structure is proposed for poly d(GC).poly d(GC). The proposed model closely resembles the crystal structure of d(CG)3.

X-ray crystal and molecular structure of a hydrated lithium picrate complex of benzo-15-crown-5; An example of non-chelation of the crown

Complexation of alkali and alkaline earth metal ions with crown ethers is well known (1) and chemical and crystallographic studies have been carried out for number of complexes (2,3). The interaction of the metal with the crown ether depends on the nature of the cation and particularly on the basicity of the anion (4) , In this paper we report the crystal and molecular structure of a lithium picrate complex of benzo-15-crown-5, the first x-ray crystallographic study of a lithlum-crown system.

Structure of 2-(2,6-dimethoxyphenyl)-2,5- dimethylbicyclo[3.2.1]octane-6,8-dione

C18H2204, orthorhombic, P212~21, a = 7.343 (4), b = 11.251 (4), c = 19.357 (4)A, Z = 4, Dr, ' = 1.20, D e = 1.254 g cm -3, F(000) = 648, p(MoKa) = 0.94 cm -~. X-ray intensity data were collected on a Nonius CAD-4 diffractometer and the structure was solved by direct methods. Full-matrix least-squares refinement gave R = 0.052 (R w = 0.045) for 1053 observed reflections. The stereochemical configuration at C(2) has been shown to be 2-exo-methyl-2-endo-(2,6-dimethoxyphenyl), i.e. (3) in contrast to the structure (2) assigned earlier based on its ~H NMR data.

Comparison of decision tree, support vector machines, and Bayesian network approaches for classification of falls in Parkinson’s disease

Being able to accurately predict the risk of falling is crucial in patients with Parkinson’s dis- ease (PD). This is due to the unfavorable effect of falls, which can lower the quality of life as well as directly impact on survival. Three methods considered for predicting falls are decision trees (DT), Bayesian networks (BN), and support vector machines (SVM). Data on a 1-year prospective study conducted at IHBI, Australia, for 51 people with PD are used. Data processing are conducted using rpart and e1071 packages in R for DT and SVM, con- secutively; and Bayes Server 5.5 for the BN. The results show that BN and SVM produce consistently higher accuracy over the 12 months evaluation time points (average sensitivity and specificity > 92%) than DT (average sensitivity 88%, average specificity 72%). DT is prone to imbalanced data so needs to adjust for the misclassification cost. However, DT provides a straightforward, interpretable result and thus is appealing for helping to identify important items related to falls and to generate fallers’ profiles.

Sequence-dependent conformation of an A-DNA double helix: The crystal structure of the octamer d(G-G-T-A-T-A-C-C)

The crystal structures of the synthetic self-complementary octamer d(G-G-T-A-T-A-C-C) and its 5-bromouracil-containing analogue have been refined to R values of 20% and 14% at resolutions of 1·8 and 2·25 Å, respectively. The molecules adopt an A-DNA type double-helical conformation, which is minimally affected by crystal forces. A detailed analysis of the structure shows a considerable influence of the nucleotide sequence on the base-pair stacking patterns. In particular, the electrostatic stacking interactions between adjacent guanine and thymine bases produce symmetric bending of the double helix and a major-groove widening. The sugar-phosphate backbone appears to be only slightly affected by the base sequence. The local variations in the base-pair orientation are brought about by correlated adjustments in the backbone torsion angles and the glycosidic orientation. Sequence-dependent conformational variations of the type observed here may contribute to the specificity of certain protein-DNA interactions.

Structure and Conformation of an Antidepressant Drug, Nitroxazepine Hydrochloride Monohydrate

CIsH20N3Oa+.C1-.H2 O, M r = 395, orthorhombic, Pn21a, a = 7.710 (4), b = 11.455 (3), c -- 21.199 (3)/k, Z = 4, V = 1872.4/k 3, D m = 1.38, D C = 1.403 g cm -3, F(000) = 832, g(Cu Kct) = 20.94 cm -l. Intensities for 1641 reflections were measured on a Nonius CAD-4 diffractometer; of these, 1470 were significant. The structure was solved by direct methods and refined to an R index of 0.045 using a blockdiagonal least-squares procedure. The angle between the least-squares planes through the benzene rings is 125.0 (5) ° and the side chain is folded similarly to one of the independent molecules of imipramine hydrochloride.

Scenario analysis of alternative vegetation management options on the greenhouse gas budget of two grazing businesses in north-eastern Australia

The emerging carbon economy will have a major impact on grazing businesses because of significant livestock methane and land-use change emissions. Livestock methane emissions alone account for similar to 11% of Australia's reported greenhouse gas emissions. Grazing businesses need to develop an understanding of their greenhouse gas impact and be able to assess the impact of alternative management options. This paper attempts to generate a greenhouse gas budget for two scenarios using a spread sheet model. The first scenario was based on one land-type '20-year-old brigalow regrowth' in the brigalow bioregion of southern-central Queensland. The 50 year analysis demonstrated the substantially different greenhouse gas outcomes and livestock carrying capacity for three alternative regrowth management options: retain regrowth (sequester 71.5 t carbon dioxide equivalents per hectare, CO2-e/ha), clear all regrowth (emit 42.8 t CO2-e/ha) and clear regrowth strips (emit 5.8 t CO2-e/ha). The second scenario was based on a 'remnant eucalypt savanna-woodland' land type in the Einasleigh Uplands bioregion of north Queensland. The four alternative vegetation management options were: retain current woodland structure (emit 7.4 t CO2-e/ha), allow woodland to thicken increasing tree basal area (sequester 20.7 t CO2-e/ha), thin trees less than 10 cm diameter (emit 8.9 t CO2-e/ha), and thin trees <20 cm diameter (emit 12.4 t CO2-e/ha). Significant assumptions were required to complete the budgets due to gaps in current knowledge on the response of woody vegetation, soil carbon and non-CO2 soil emissions to management options and land-type at the property scale. The analyses indicate that there is scope for grazing businesses to choose alternative management options to influence their greenhouse gas budget. However, a key assumption is that accumulation of carbon or avoidance of emissions somewhere on a grazing business (e.g. in woody vegetation or soil) will be recognised as an offset for emissions elsewhere in the business (e.g. livestock methane). This issue will be a challenge for livestock industries and policy makers to work through in the coming years.

An (O)over-tilde(mn) Gomory-Hu Tree Construction Algorithm for Unweighted Graphs

We present a fast algorithm for computing a Gomory-Hu tree or cut tree for an unweighted undirected graph G = (V, E). The expected running time of our algorithm is (O) over tilde (mc) where vertical bar E vertical bar = m and c is the maximum u-v edge connectivity, where u, v is an element of V. When the input graph is also simple (i.e., it has no parallel edges), then the u-v edge connectivity for each pair of vertices u and v is at most n - 1; so the expected run-ning time of our algorithm for simple unweighted graphs is (O) over tilde (mn). All the algorithms currently known for constructing a Gomory-Hu tree [8, 9] use n - 1 minimum s-t cut (i.e., max flow) subroutines. This in conjunction with the current fastest (O) over tilde (n(20/9)) max flow algorithm due to Karger and Levine[11] yields the current best running time of (O) over tilde (n(20/9)n) for Gomory-Hu tree construction on simple unweighted graphs with m edges and n vertices. Thus we present the first (O) over tilde (mn) algorithm for constructing a Gomory-Hu tree for simple unweighted graphs. We do not use a max flow subroutine here; we present an efficient tree packing algorithm for computing Steiner edge connectivity and use this algorithm as our main subroutine. The advantage in using a tree packing algorithm for constructing a Gomory-Hu tree is that the work done in computing a minimum Steiner cut for a Steiner set S subset of V can be reused for computing a minimum Steiner cut for certain Steiner sets S' subset of S.

The structure of monopotassium phosphoenolpyruvate

CaH406P-.K +, M r = 206.10, is orthorhombic, space group Pbca (from systematic absences), a = 14.538(4), b = 13.364(5), c = 6.880 (6)A, U = 1383.9 A 3, D x = 2.07 Mg m -a, Z = 8, ~.(Mo Ka) = 0.7107/~, p(MO Ka) = 1.015 mm -1. The final R value is 0.042 for a total of 1397 reflections. The high energy P-O(13) and the enolic C(1)-O(13) bonds are 1.612 and 1.374 A respectively. The enolpyruvate moiety is essentially planar. The orientation of the phosphate with respect to the pyruvate group in PEP.K is distinctly different from that in the PEP-cyclohexylammonium salt, the torsion angle C (2)-C (1)-O(13)- P being -209.1 in the former and -90 ° in the latter. The K + ion binds simultaneously to both the phosphate and carboxyl ends of the same PEP molecule. The ester O(13) is also a binding site for the cation. The K + ion is coplanar with the pyruvate moiety and binds to 0(22) and O(13) almost along their lone-pair directions. The carbonyl 0(22) prefers to bind to the K + ion rather than take part in the formation of hydrogen bonds usually observed in carboxylic acid structures.

Crystal and molecular structure of the quinoxaline antibiotic analog TANDEM (des-N-tetramethyltriostin A)

The crystal structure of TANDEM (des-N-tetramethyltriostin A), a synthetic analogue of the quinoxaline antibiotic triostin A, has been determined independently at -135 and 7 'C and refined to R values of 0.088 and 0.147, respectively. The molecule has approximate 2-fold symmetry, with the quinoxaline chromophores and the disulfide cross-bridge projecting from opposite sides of the peptide ring. The quinoxaline groups are nearly parallel to each other and separated by about 6.5 A. The peptide backbone resembles a distorted antiparallel 13 ribbon joined by intramolecular hydrogen bonds N-H(LVal)--O(L-Ala). At low temperatures, the TANDEM molecule is surrounded by a regular first- and second-order hydration sphere containing 14 independent water molecules. At room temperature, only the first-order hydration shell is maintained. Calculations of the interplanar separation of the quinoxaline groups as a function of their orientation with respect to the peptide ring support the viability of TANDEM to intercalate bifunctionally into DNA.

Structure of a peptide oxazolone: 2-(1'-benzyloxycarbonylamino-1'-methylethyl)-4,4-dimethyl-5-oxazolone

C16H20N204, monoclinic, P21, a = 6.270 (1),b= 11.119(3),c= ll.640(4)A, fl= 100.7 (2)°,Dm = 1-27 (flotation), Dc = 1-26 Mg m -3, Z = 2. The structure has been refined to a final R value of 0.041 for 1584 independent counter-measured reflections. The oxazolone ring in the molecule is nearly planar. The exocyclic O atom is 0.065 A out of the plane defined by the other four atoms in the ring belonging to the lactone group. The difference in length between the two adjacent C-O bonds in the ring is small, but significant. The crystal structure is stabilized by van der Waals interactions and a N--H... N hydrogen bond.

Structure of (4S)-2,4-dimethyl-1,2-dihydropyrazino[2,1-b]quinazoline-3(4H),6-dione

C13HI3N302, orthorhombic, P2~2121, a = 17.443 (5), b = 11.650 (4), c = 5.784 (1)/~, Z = 4, d m = 1.456, d c = 1.429 Mg m -3, F(000) = 512, g(Cu Ka) = 0.843 mm-L The R index is 0.040 for 1358 significant reflections. The structure is stabilized by C-H...O interactions. The N-methylated eis peptide group which forms part of a six-membered ring is non-planar. The torsion angle about the peptide bond is -6.1 (4) ° and the peptide bond length is 1.337 (3) A.