Lichanura, L. trivirgata

Number of Pages: 2Integrative BiologyGeological Science

Benchmarking citation measures among the Australian education professoriate

Individual researchers and the organisations for which they work are interested in comparative measures of research performance for a variety of purposes. Such comparisons are facilitated by quantifiable measures that are easily obtained and offer convenience and a sense of objectivity. One popular measure is the Journal Impact Factor based on citation rates but it is a measure intended for journals rather than individuals. Moreover, educational research publications are not well represented in the databases most widely used for calculation of citation measures leading to doubts about the usefulness of such measures in education. Newer measures and data sources offer alternatives that provide wider representation of education research. However, research has shown that citation rates vary according to discipline and valid comparisons depend upon the availability of discipline specific benchmarks. This study sought to provide such benchmarks for Australian educational researchers based on analysis of citation measures obtained for the Australian education professoriate

The Semigroups B\u3csub\u3e2\u3c/sub\u3e and B\u3csub\u3e0\u3c/sub\u3e are Inherently Nonfinitely Based, as Restriction Semigroups

The five-element Brandt semigroup B2 and its four-element subsemigroup B0, obtained by omitting one nonidempotent, have played key roles in the study of varieties of semigroups. Regarded in that fashion, they have long been known to be finitely based. The semigroup B2 carries the natural structure of an inverse semigroup. Regarded as such, in the signature {⋅, -1}, it is also finitely based. It is perhaps surprising, then, that in the intermediate signature of restriction semigroups — essentially, forgetting the inverse operation x ↦ x-1 and retaining the induced operations x ↦ x+ = xx-1 and x ↦ x* = x-1x — it is not only nonfinitely based but inherently so (every locally finite variety that contains it is also nonfinitely based). The essence of the nonfinite behavior is actually exhibited in B0, which carries the natural structure of a restriction semigroup, inherited from B2. It is again inherently nonfinitely based, regarded in that fashion. It follows that any finite restriction semigroup on which the two unary operations do not coincide is nonfinitely based. Therefore for finite restriction semigroups, the existence of a finite basis is decidable modulo monoids . These results are consequences of — and discovered as a result of — an analysis of varieties of strict restriction semigroups, namely those generated by Brandt semigroups and, more generally, of varieties of completely r-semisimple restriction semigroups: those semigroups in which no comparable projections are related under the generalized Green relation �. For example, explicit bases of identities are found for the varieties generated by B0 and B2

The life cycles of cryptogams

Meiosis and karyogamy are recognized as control points in the life cycle of cryptogams. The control of meiosis is evidently complex and in yeast, and by analogy in all cryptogams, involves progressive gene activation. The causes of the delay in meiosis in diplohaplontic and diplontic organisms, and the manner in which the block is removed remain to be discovered. There is accumulating evidence that cytoplasmic RNA plays an important role in meiotic division.Many features of gametogenesis are still obscure. The tendency to oogamy has provided the opportunity for the laying down of long-lived messenger RNA in the abundant cytoplasm of the female gamete. The sporophytic nature of the developing zygote can in this way be partially pre-determined. There is evidence that this is the situation in the ferns.Specific molecules (probably arabino-galacto-proteins) on the surface of the plasma membrane are likely to account both for gametic selection, and the readiness with which appropriate gametes fuse. The dikaryotic condition indicates that nuclear fusion is not inevitable following plasmogamy. The ultimate fusion of the nuclei may result from quite simple changes in the nuclear surface. Exposure of lipid, for example, would lead to fusion as a result of hydrophobic forces.Aberrations of cryptogamic life cycles are numerous. The nuclear relationships of many aberrant cycles are unknown. In general it appears that the maintenance of sporophytic growth depends upon the presence of at least two sets of chromosomes. Conversely the maintenance of gametophytic growth in cultures obtained aposporously appears to be impossible in the presence of four sets of chromosomes, or more. These results raise important problems of the effect of gene dosage on development.La meiosis y la cariogamia son reconocidas como puntos de control en los ciclos de vida de las criptógamas. El control de la meiosis es evidentemente complejo y en levaduras, y por analogía en todas las criptógamas, incluye la activación progresiva del gen. Las causas de este retraso en la meiosis de los organismos diplohaplónticos y diplónticos y la manera en que se elimina el bloqueo aun se desconoce. Existe una acumulación de evidencias que indican que el RNA citoplásmico juega un importante papel en la división meiótica.Muchas características de la gametogénesis están aún oscuras. La tendencia hacia la oogamia ha permitido la oportunidad de establecer la longevidad del ARN mensajero en el abundante citoplasma del gameto femenino. La naturaleza del esporófito desarrollada a partir del cigoto puede ser, en este sentido, parcialmente predeterminada. Hay evidencias que esta es la situación en los helechos.La selección gamética y la prontitud con que se fusionan los gametos apropiados, probablemente se deba a moléculas específicas (quizás arabino-galacto-proteínas) de la superficie de la membrana plasmática. La condición dicariótica indica que la fusión nuclear no es inevitable como consecuencia de la plasmogamia. La fusión definitiva de los núcleos puede resultar de unos cambios bastante simples en la superfice nuclear. La exposición de lípidos, por ejemplo, conduciría a la fusión como resultado de fuerzas hidrofóbicas.Las aberraciones en el ciclo de vida de las criptógamas son numerosas. Las relaciones nucleares de muchos de los ciclos aberrantes son desconocidas. En general parece que el mantenimiento del crecimiento esporofítico depende de la presencia, por lo menos, de dos juegos de cromosomas. De manera contraria, el mantenimiento del crecimiento del gametófito en cultivos obtenidos apospóricamente parece ser imposible en presencia de cuatro juegos de cromosomas o más. Estos resultados aumentan la importancia de los problemas de la dosificación del gen en el desarrollo

Varieties of \u3cem\u3eP\u3c/em\u3e-Restriction Semigroups

The restriction semigroups, in both their one-sided and two-sided versions, have arisen in various fashions, meriting study for their own sake. From one historical perspective, as “weakly E-ample” semigroups, the definition revolves around a “designated set” of commuting idempotents, better thought of as projections. This class includes the inverse semigroups in a natural fashion. In a recent paper, the author introduced P-restriction semigroups in order to broaden the notion of “projection” (thereby encompassing the regular *-semigroups). That study is continued here from the varietal perspective introduced for restriction semigroups by V. Gould. The relationship between varieties of regular *-semigroups and varieties of P-restriction semigroups is studied. In particular, a tight relationship exists between varieties of orthodox *-semigroups and varieties of “orthodox” P-restriction semigroups, leading to concrete descriptions of the free orthodox P-restriction semigroups and related structures. Specializing further, new, elementary paths are found for descriptions of the free restriction semigroups, in both the two-sided and one-sided cases