Developmental expression of a class IV POU gene in the gastropod Haliotis asinina supports a conserved role in sensory cell development in bilaterians

POU-IV genes regulate neuronal development in a number of deuterostomes (chordates) and ecdysozoans (arthropods and nematodes). Currently their function and expression in the third bilaterian clade, the Lophotrochozoa, comprising molluscs, annelids and. their affiliates, is unclear. Herein we characterise the developmental expression of HasPOU-IV in the gastropod mollusc, Haliotis asinina. The POU-IV gene is transiently expressed in I I distinct larval territories during the first 3 days of development. HasPOU-IV is first expressed in sets of ventral epidermal cells in the newly hatched trochophore larvae. As larval morphogenesis proceeds, we observe HasPOU-IV transcripts in cells that putatively form a range of sensory systems including chemo- and mechanosensory cells in the foot, cephalic tentacles, the ctenidia. the geosensory statocyst and the eyes. By comparing HasPOU-IV expression with POU-IV genes in other bilaterians we infer that this class of POU-domain genes had an ancestral role in regulating sensory cell development.

The number of rational points of a class of Artin-Schreier curves

We determine the number of F-q-rational points of a class of Artin-Schreier curves by using recent results concerning evaluations of some exponential sums. In particular, we determine infinitely many new examples of maximal and minimal plane curves in the context of the Hasse-Weil bound. (C) 2002 Elsevier Science (USA).

The compositional inverse of a class of permutation polynomials over a finite field

A new class of bilinear permutation polynomials was recently identified. In this note we determine the class of permutation polynomials which represents the functional inverse of the bilinear class.

Determinants of physical activity in middle school children

Objective: To evaluate the theory of reasoned action (TRA) and planned behavior (TPB) in predicting moderate-to-vigorous physical activity (MVPA) in sixth-grade youth. Methods: One hundred ninety-eight students completed a questionnaire measuring attitudes, subjective norms, perceived behavioral control, and intentions to be active. MVPA was measured using the CSA 7,164 accelerometer. Results: Although demonstrating an acceptable fit, the TRA and TPB accounted for only a small percentage of the variance in MVPA. In support of the TPB: the addition: of control perceptions to the reasoned! action model! added to the prediction of intentions and MVPA. Conclusion: Within our sample of sixth graders, the utility of the, TRA or TPB;as a framework for activity interventions appears to be limited.

Kinematics of oblique collision and ramping inferred from microstructures and strain in middle crustal rocks, central Southern Alps, New Zealand

The hanging wall of the Alpine Fault near Franz Josef Glacier has been exhumed during the past similar to2-3 m.y. providing a sample of the ductilely deformed middle crust of a modem obliquely convergent orogen. Presently exposed rocks of the Pacific Plate are inferred to have undergone several phases of ductile deformation as they moved westward above a mid-crustal detachment. Initially they were transpressed across the outboard part of the orogen, resulting in oblate fabrics with a down-dip stretch. Later, they encountered the Alpine Fault, experiencing an oblique-slip backshearing on vertical planes. This escalator-like deformation tilted and thinned the incoming crust onto that crustal-scale oblique ramp. This style of hanging wall deformation may affect only the most rapidly uplifting, central part of the Southern Alps because of the low flexural rigidity of the crust in that region and its displacement over a relatively sharp ramp-angle at depth. A 3D transpressive flow affected mylonites locally near the fault, but their shear direction remained parallel to plate motion, ruling out ductile 'extrusion' as an important process in this orogen. Outside the mylonite zone, late Cenozoic shortening is inferred to be modest (30-40%), as measured from deformation of younger biotite grains. Oblique collision is dominated by translation on the Alpine Fault, and rocks migrate rapidly through the deforming zone, preventing the accumulation of large finite strains. Transpression may play a minor role in oblique collision. (C) 2001 Elsevier Science Ltd. All rights reserved.

Perceptions of younger, middle-aged, and older adults in Australia and Japan: Stereotypes and age group vitality

This study investigated the perceptions of young adults in Japan and Australia about their own age group, as well as middle-aged and older adults. Using a self-administered questionnaire, 155 Japanese and 171 Australian students rated people in the three age groups on traits of personal vitality and benevolence, and also rated their age group vitalities. Results indicated that Australians perceived both middle-aged and older adults in more positive terms than did Japanese and also perceived the vitality of these age groups as higher. On the other hand, both Japanese and Australian young people judged the vitality of their own group as lower than that of middle-aged adults. These results suggest that norms of filial piety, especially its respect dimension, in Japan may be eroding, whereas older Australians may be gaining in social stature.

Class benefits of AT1 antagonists in Type 2 diabetes with nephropathy

Diabetes mellitus has reached epidemic proportions in many countries and is the most common cause of end stage renal disease (ESRD). The angiotensin II receptor-1 (AT1) antagonists losartan and irbesartan have recently been evaluated as renoprotective agents in large clinical trials of patients with Type 2 diabetes and nephropathy. In the Reduction of End points in Non-insulin-dependent diabetes mellitus with the Angiotensin II Antagonist (RENAAL) study, losartan decreased the number of patients reaching the primary end point of a composite of measures of neuropathy. The relative risk reduction was ~ 15% with losartan and this was due to a reduction in both the doubling of creatinine concentration (25%) and of ESRD (28%) but not in death. In the Irbesartan Diabetic Nephropathy Trial (IDNT), the beneficial effect of irbesartan was mainly against the doubling of the baseline creatinine concentration (37% risk reduction) but there was also a 20% reduction in the onset of ESRD. Irbesartan had no effect on mortality. Beneficial effects occurred in addition to blood pressure being controlled by agents other than the AT1 antagonists. These clinical trials suggest that there may be a class renoprotective action with AT1 antagonists, although the mechanism is not clear. Patients with Type 2 diabetes and nephropathy should receive either an AT1 antagonist or the angiotensin converting enzyme inhibitor ramipril to ensure renoprotection.

Aligning school reform and teacher education reform in the middle years: An Australian case study

This paper discusses the development of a new Bachelor of Education (Middle Years of Schooling) at The University of Queensland. The middle years of schooling have increasingly been the focus of education reform initiatives in Australia, but this has not been accompanied by significant increases in the number of teacher education institutions offering specialised middle schooling-level teacher preparation programmes. Considering the rapidly changing social and economic context and the emergent state of middle schooling in Australia, the programme represented a conceptual and practical opportunity and challenge for The University of Queensland team. Working collaboratively, the team sought to design a teacher education preservice programme that was both responsive and generative: that is, responsive to local school contexts and to current educational research and reform at national and international levels; and generative of cutting-edge theories and practices associated with middle schooling, teachers' work, and teacher education. This paper focuses on one component of the Middle Years of Schooling Teacher Education programme at The University of Queensland; namely, the practicum. We first present the underlying principles of the practicum programme and then examine "dilemmas" that emerged early in the practicum. These issues and tensions were associated with the ideals of "middle years" philosophy and the pragmatics of school reform associated with that new approach. In this paper, and within this context, we explore what it means to be both responsive and generative, and describe how we as teacher educators negotiated between the extremes these terms implied.

A naturally selected dimorphism within the HLA-B44 supertype alters class I structure, peptide repertoire, and T cell recognition

HLA-B*4402 and B*4403 are naturally occurring MHC class I alleles that are both found at a hi,,h frequency in all human populations, and vet they only differ by one residue on the alpha2 helix (B*4402 Aspl56-->B*4403 Leu156) CTLs discriminate between HLA-B*4402 and B*4403, and these allotypes stimulate strong mutual allogeneic responses reflecting their known barrier to hemopoeitic stem cell transplantation. Although HLA-B*4402 and B*4403 share >95% of their peptide repertoire, B*4403 presents more unique peptides than B*4402, consistent with the stronger T cell alloreactivity observed toward B*4403 compared with B*4402. Crystal structures of B*4402 and B*4403 show how the polymorphisin at position 156 is completely buried and yet alters both the peptide and the heavy chain conformation, relaxing ligand selection by B*4403 compared with B*4402. Thus, the polymorphism between HLA-B*4402 and B 4403 modifies both peptide repertoire and T cell recognition, and is reflected lit the paradoxically powerful alloreactivity that occurs across this minimal mismatch. The findings suggest that these closely related class I genes are maintained lit diverse human populations through their differential impact on the selection of peptide ligands and the T cell repertoire.

Zygosity Diagnosis in the Absence of Genotypic Data: An Approach Using Latent Class Analysis

For zygosity diagnosis in the absence of genotypic data, or in the recruitment phase of a twin study where only single twins from same-sex pairs are being screened, or to provide a test for sample duplication leading to the false identification of a dizygotic pair as monozygotic, the appropriate analysis of respondents' answers to questions about zygosity is critical. Using data from a young adult Australian twin cohort (N = 2094 complete pairs and 519 singleton twins from same-sex pairs with complete responses to all zygosity items), we show that application of latent class analysis (LCA), fitting a 2-class model, yields results that show good concordance with traditional methods of zygosity diagnosis, but with certain important advantages. These include the ability, in many cases, to assign zygosity with specified probability on the basis of responses of a single informant (advantageous when one zygosity type is being oversampled); and the ability to quantify the probability of misassignment of zygosity, allowing prioritization of cases for genotyping as well as identification of cases of probable laboratory error. Out of 242 twins (from 121 like-sex pairs) where genotypic data were available for zygosity confirmation, only a single case was identified of incorrect zygosity assignment by the latent class algorithm. Zygosity assignment for that single case was identified by the LCA as uncertain (probability of being a monozygotic twin only 76%), and the co-twin's responses clearly identified the pair as dizygotic (probability of being dizygotic 100%). In the absence of genotypic data, or as a safeguard against sample duplication, application of LCA for zygosity assignment or confirmation is strongly recommended.

A class B switch-mode assisted linear amplifier

A switch-mode assisted linear amplifier (SMALA) combining a linear (Class B) and a switch-mode (Class D) amplifier is presented. The usual single hysteretic controlled half-bridge current dumping stage is replaced by two parallel buck converter stages, in a parallel voltage controlled topology. These operate independently: one buck converter sources current to assist the upper Class B output device, and a complementary converter sinks current to assist the lower device. This topology lends itself to a novel control approach of a dead-band at low power levels where neither class D amplifier assists, allowing the class B amplifier to supply the load without interference, ensuring high fidelity. A 20 W implementation demonstrates 85% efficiency, with distortion below 0.08% measured across the full audio bandwidth at 15 W. The class D amplifier begins assisting at 2 W, and below this value, the distortion was below 0.03%. Complete circuitry is given, showing the simplicity of the additional class D amplifier and its corresponding control circuitry.