An anatomical study of the microcirculation in the rabbit femur

Summary A technique is described which will allow a study of the microcirculation to a long bone such as the femur. It involves use of a silicone rubber compound (Microfil) in combination with the Spalteholz clearing technique. Preliminary results in the normal rabbit skeleton suggest that this technique can be used to study the changes in vascularity which occur under various pathological conditions.     

A histochemical study of denervated marsupial hemidiaphragm

Summary The marsupial (quokka) hemidiaphragm showed postdenervation hypertrophy and subsequent atrophy. The type II muscle fibres hypertrophied up to 20 days postoperation and then regressed. However, the type I fibres hypertrophied throughout the experimental period (100 days) studied. Unlike denervated eutherian hemidiaphragm, fibre-splitting was absent in the denervated marsupial muscle. An enhancement of the ATPase reaction in the denervated type I fibres may be due to dedifferentiation. Presumably innervation exerts a negative control and prevents increase of type I fibre size in the normal hemidiaphragm.I am grateful to Dr O.M. Sola and Professor B.A. Kakulas for their help and encouragement.     

Neighborhood topological effect on grain topology-size relationship in three-dimensional polycrystalline microstructures

A new grain topology-size relationship in three-dimensional(3D)polycrystalline microstructures has recently been established by considering the effects of non-random first nearest neighbor grains.In this contribution,a generalized form for this relationship is presented by considering the interactions of kth(k=1,2,3…)nearest neighbor grains,and large scale Monte Carlo-Potts model simulation is used to investigate the general neighborhood topological effect on the topology-size relationship.The results show that,unlike their first nearest neighbors(k=1),the topological correlations of 3D grains with their kth layers(k 2)of nearest-neighbors may have trivial effect on the topology-size relationship.     

A histochemical study of denervated marsupial hemidiaphragm.

The marsupial (quokka) hemidiaphragm showed postdenervation hypertrophy and subsequent atrophy. The type II muscle fibres hypertrophied up to 20 days postoperation and then regressed. However, the type I fibres hypertrophied throughout the experimental period (100 days) studied. Unlike denervated eutherian hemidiaphragm, fibre-splitting was absent in the denervated marsupial muscle. An enhancement of the ATPase reaction in the denervated type I fibres may be due to dedifferentiation. Presumably innervation exerts a 'negative control' and prevents increase of type I fibre size in the normal hemidiaphragm.     

Molecular evolution of rice S 5 n and functional comparison among different sequences

The wide compatibility gene, S ₅ ⁿ , can overcome embryo sac sterility between indica and japonica subspecies of rice. Therefore, it is very important to characterize the features of the S ₅ ⁿ sequence to reveal the origin and evolution of S ₅ ⁿ . In this paper, 26 cultivated rice haplotypes and 22 wild rice accessions harboring S ₅ ⁿ were used to sequence S ₅ ⁿ . The results showed that 15 genotypes among the 48 materials were fully consistent with control cultivar 02428 (CK). The other 33 accessions had different degrees of variation in the S ₅ ⁿ sequence. Variations in the coding region mainly occurred in the second exon and eight materials showed a 10-bp deletion at 1710?C1719 bp, including wild (O. nivara) and cultivated rice, such as IRW501 and Yuetai B. S ₅ ⁿ sequences were not biased and evolved neutrally. The 48 materials could be divided into 4 categories using a phylogenetic tree of the amino acid sequences. Most of the wild rice clustered together, and the cultivated rice clustered into another group. Eight cultivated rice and O. nivara (wild rice) clustered in another group, which were found to lack 10 consecutive bases in exon 2. Eight rice varieties with high numbers of differences in their S ₅ ⁿ coding regions were crossed with testers (typically indica and japonica) to produced test cross F₁ populations. The F₁s were examined for their ability to overcome indica-japonica hybrid sterility. The result showed that the embryo sac fertility of S ₅ ⁿ -containing hybrids increased significantly compared with control hybrids, but there were no differences among the materials with divergent sequences, indirectly proving that S ₅ ⁿ is a non-functional gene.     

Effect of salinity and planting density on physiological responses of Allenrolfea occidentalis

Physiological responses of Allenrolfea occidentalis to salinity and seedling density were investigated. Effects of salinity (0, 200, 400, 600, 800, and 1000 mM NaCl) and 3 planting densities (2000, 4000, 6000 plants m -2 ) on the growth, survival, and ecophysiology of A. occidentalis , a stem succulent inland halophyte, were studied under controlled greenhouse conditions. Plants were grown in a sand culture using subirrigation. Dry mass of roots was highest at 600 mM NaCl at low density (2000 plants m -2 ), but declined as salinity increased. Tissue water content was highest at the 200 mM NaCl treatment and decreased with increased salinity. Water potential of the plants became more negative with increasing salinity due to the accumulation of NaCl in the leaves. Inorganic ions, especially Na + and Cl - , contributed substantially to dry mass. Na + and Cl - concentration in shoots and roots increased when NaCl level was increased while K + , Ca ++ , Mg ++ , SO 4 -- , and NO 3 - contents decreased. Net photosynthesis increased at low salinity (200 mM), but photosynthesis at other salinities was not significantly different from the control. While A. occidentalis is very salt tolerant and photosynthesis functioned reasonably well at high salinities, extremely high salinity did decrease dry mass of roots and shoots.