Transient processes in an oscillatory circuit caused by stepwise phase changes

Transient processes at the output of an isolated oscillatory circuit caused by stepwise phase changes at the circuit input are studied in the time and frequency domains. A mathematical model of this type of transient processes in the form of a narrowband process is presented. Analytical expressions describing the behavior of the transient process in the time and frequency domains are obtained. New features of this type of transient processes are revealed.     

Functionalization of Silicon Surfaces for Device Applications

Over the past decade, there has been increasing interest in functionalizing silicon surfaces, avoiding the ubiquitous oxide overlayer utilized in most integrated circuits based upon silicon. While silicon is clearly the backbone material of the microelectronics industry, an understanding of its surface chemistry still remains in preliminary stages. The native oxide overlayer on silicon chips has served admirably well for most microelectronic applications but as the features on integrated circuits become increasingly small, the ability to tailor the interfacial properties of the surface is extremely desirable. As the well known Moore's law describes, the number of devices on an integrated circuit has been increasing exponentially since the early 1960's, approximately doubling every year to 18 months. The smallest feature on a Pentium processor chip is now about 300 nm, and both industry and academia look to make even tinier surface features and devices as the state-of-the-art moves from ultra-to giga-scale integration, with over 10 to 100 million transistors per chip. Because the surface properties of these nanoscale devices will have crucial effects on their performance, new surface terminations and the chemical tools to access them are required.     

Gatekeeping or gate slippage? A national survey of counseling educators in Australian undergraduate and postgraduate academic training programs.

Counseling educators fulfill a complex and demanding role as gatekeepers. The role serves a quality control function and involves ethical and educational responsibilities; it also interfaces with a confounding array of issues. This study was undertaken to establish how counseling educators view and experience the gatekeeping function, and to identify the mechanisms implemented by training programs to facilitate educators in the gatekeeping process. Educators from across Australia involved in counseling training at the bachelor's degree or higher award level were surveyed (n = 63, response rate = 34%). Findings suggested that educators are highly motivated by their sense of responsibility toward the counseling profession when assessing students. Nevertheless, their gatekeeping efforts are often compromised having been predominantly impeded by a lack of clear evidence of the problematic issues and leniency biases within their programs. In addition, gatekeeping efforts have not been generally supported by program initiatives, such as written policy and procedures, which are recognized to be facilitative of the gatekeeping process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Challenges in developing an integrated catchment management model

Directives and policies increasingly call for more integrated management of land and water. Frameworks such as integrated catchment management may address these calls, and yet their implementation requires decisions to be taken under conditions of extreme complexity and uncertainty. This paper summarises a participatory framework through which decision‐makers, experts and system modellers can collaboratively develop an integrated model to support such decisions. A feasibility study showed the potential of the framework. An operational version of the model, able to analyse the effects of 50 management options on 20 indicators, is estimated to require in the order of 225 man‐months from system modellers, alongside substantial inputs from stakeholders. The significant technical challenges confronting such an exercise may be overshadowed by the institutional challenges, including the fundamental question of whether organisations are truly committed. However, the reward for overcoming such challenges is the opportunity to achieve genuine improvements in the social, economic and environmental quality of our catchments.     

The Kinetic Inversion Problem in Ligand-Binding Heme Proteins

For a two-dimensional potential of intersecting parabolic bowls, we obtain an analytical approximation for the survival probability in the limit that the reactive mode is diffusive and the perpendicular protein mode frozen. The approximation is used in an automated computer algorithm for determining the parameters of the potential. Using this program, we are able to obtain a reasonably good fit to the low- temperature data of CO binding to horse myoglobin. We find, however, that features of the potential such as the saddle-point energy and the effective barrier, expected to dictate the high-temperature kinetics, are not uniquely determined for this potential from fitting the low-temperature data.     

Indium tin oxide nanopillar electrodes in polymer/fullerene solar cells

Using high surface area nanostructured electrodes in organic photovoltaic (OPV) devices is a route to enhanced power conversion efficiency. In this paper, indium tin oxide (ITO) and hybrid ITO/SiO(2) nanopillars are employed as three-dimensional high surface area transparent electrodes in OPVs. The nanopillar arrays are fabricated via glancing angle deposition (GLAD) and electrochemically modified with nanofibrous PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate)). The structures are found to have increased surface area as characterized by porosimetry. When applied as anodes in polymer/fullerene OPVs (architecture: commercial ITO/GLAD ITO/PEDOT:PSS/P3HT:PCBM/Al, where P3HT is 2,5-diyl-poly(3-hexylthiophene) and PCBM is [6,6]-phenyl-C(61)-butyric acid methyl ester), the air-processed solar cells incorporating high surface area, PEDOT:PSS-modified ITO nanoelectrode arrays operate with improved performance relative to devices processed identically on unstructured, commercial ITO substrates. The resulting power conversion efficiency is 2.2% which is a third greater than for devices prepared on commercial ITO. To further refine the structure, insulating SiO(2) caps are added above the GLAD ITO nanopillars to produce a hybrid ITO/SiO(2) nanoelectrode. OPV devices based on this system show reduced electrical shorting and series resistance, and as a consequence, a further improved power conversion efficiency of 2.5% is recorded.     

Deficiency of the ATM protein expression defines an aggressive subgroup of B-cell chronic lymphocytic leukemia

The gene mutated in ataxia telangiectasia, ATM, on human chromosome 11q22-q23 is implicated in cell cycle control and DNA repair. Ataxia telangiectasia patients as well as ATM-deficient mice are immune deficient and develop lymphoproliferative disease. Abnormalities in 11q22.3-q23.1 have also been described in B-cell chronic lymphocytic leukemia (B-CLL). We analyzed B-CLL samples for loss of heterozygosity (LOH) using microsatellite markers located at the ATM (D11S2179), mixed-lineage leukemia (MLL; D11S1356), and BCL1 (D11S987) loci, all of which are located around 11q23. Five (14%) of 36 informative cases showed LOH at the ATM gene, and two of these five cases had LOH at the MLL gene. No LOH was detected at the BCL1 locus, and none of the cases showed LOH at the MLL gene without LOH at the ATM gene. Four of these five cases with LOH at the ATM gene were studied for ATM protein expression by Western blot analysis. All four cases lacked ATM protein. An additional 111 cases of B-CLL were studied for expression of ATM protein by Western blot analysis and RIA. Thirty-eight (34%) of these cases showed ATM levels <50% of that seen in normal lymphoid cells. No morphological or immunophenotypic difference was observed between ATM-deficient B-CLL cases and cases with normal ATM expression. However, patients with ATM deficiency had significantly shorter survival times (35.66 versus 97.3 months; P = 0.003) and more aggressive disease, suggesting that ATM is involved in the leukemogenesis of B-CLL. These data also suggest that the ATM gene may play a role in the reported 11q23 abnormality in B-CLL, which also characterizes an aggressive disease.