Identification of putative regulatory signals including the HAP1 binding site in the upstream sequence of the Aspergillus nidulans cytochrome c gene (cycA).

We speculate that a HAP1-like protein, similar to those which regulate oxygen transcriptional activation of many yeast respiratory genes, will probably also regulate the A. nidulans cytochrome c (cycA) gene. As part of a study to investigate the significance of a putative HAP1 (Haem Activator Protein) binding site in the regulatory region of the cycA gene, routine sequencing revealed an error in the published sequence (Raitt et al. 1994 Mol. Gen. Genet. 242: 17-22). Examination of the corrected sequence, including RT-PCR analysis of cycA mRNA, showed that an extra intron was present, and that the published translational start site was incorrect. This meant that the putative HAP1-binding site proposed by Raitt et al. could not be a regulatory element. However, further sequence analysis of the upstream sequence of the corrected cycA gene revealed putative regulatory signals, including possible HAP1 binding sites which are a closer match to recently reported yeast consensus sequences (Ha et al. 1996 Nucl. Acids Res. 24: 1453-1459)

Factors associated with elevated blood lead levels in inner ·city Cape Town children

A cross-sectional analytical study was carried out to determine risk factors for childhood lead exposure. Blood lead levels of inner-city Sub A coloured children living in Woodstock were examined in relation to information obtained by questionnaire on environmental and social factors. The mean blood lead concentration of the population was 18 ug/dl. Thirteen per cent of children had blood lead levels'≥ 25 ug/dl, the present USA 'action' level. Dusty homes and homes in a poor state of repair, over-crowding, low parental education and income, and other aspects related to family structure and socio-economic status, were associated with raised blood lead levels. It is suggested that social factors assume importance in predisposing children 'to lead in the environment. In particular, the over-crowded nature of the homes could have a direct bearing on the quality of the care-giving environment, providing opportunity for children's activities to go unsupervised. This could lead young children to be more exposed to accessible sources of lead associated with poor housing conditions. More attention needs to be given to examining the interaction of social and environmental factors in studies of childhood lead exposure

Quantum channels in nonlinear optical processes

Quantum electrodynamics furnishes a new type of representation for the characterisation of nonlinear optical processes. The treatment elicits the detailed role and interplay of specific quantum channels, information that is not afforded by other methods. Following an illustrative application to the case of Rayleigh scattering, the method is applied to second and third harmonic generation. Derivations are given of parameters that quantify the various quantum channels and their interferences; the results are illustrated graphically. With given examples, it is shown in some systems that optical nonlinearity owes its origin to an isolated channel, or a small group of channels. © 2009 World Scientific Publishing Company

Twenty Questions: The Most Common Inquiries Regarding Bean Leaf Beetle Biology, Ecology and Management

The bean leaf beetle has become a more significant pest of soybeans during the last several years. Not only do the beetles feed on leaves and pods, but they also transmit bean pod mottle virus. This presentation will review the most commonly asked questions about the biology, ecology and management of this pest. Answers to each question will help you better understand the pest and manage your soybeans in 2003

Sensitivity Analysis of a Comprehensive Model for a Miniature-Scale Linear Compressor for Electronics Cooling

A comprehensive model of a linear compressor for electronics cooling was previously presented by Bradshaw et al. (2011). The current study expands upon this work by first developing methods for predicting the resonant frequency of a linear compressor and for controlling its piston stroke. Key parameters governing compressor performance – leakage gap, eccentricity, and piston geometry – are explored using a sensitivity analysis. It is demonstrated that for optimum performance, the leakage gap and frictional parameters should be minimized. In addition, the ratio of piston stroke to diameter should not exceed a value of one to minimize friction and leakage losses, but should be large enough to preclude the need for an oversized motor. An improved linear compressor design is proposed for an electronics cooling application, with a predicted cooling capacity of 200 W a cylindrical compressor package size of diameter 50.3 mm and length 102 mm

Chemical NOx budget in the upper troposphere over the tropical South Pacific

The chemical NOx budget in the upper troposphere over the tropical South Pacific is analyzed using aircraft measurements made at 6-12 km altitude in September 1996 during the Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM) Tropics A campaign. Chemical loss and production rates of NOx along the aircraft flight tracks are calculated with a photochemical model constrained by observations. Calculations using a standard chemical mechanism show a large missing source for NOx; chemical loss exceeds chemical production by a factor of 2.4 on average. Similar or greater NOx budget imbalances have been reported in analyses of data from previous field studies. Ammonium aerosol concentrations in PEM-Tropics A generally exceeded sulfate on a charge equivalent basis, and relative humidities were low (median 25% relative to ice). This implies that the aerosol could be dry in which case N2O5 hydrolysis would be suppressed as a sink for NOx. Suppression of N2O5 hydrolysis and adoption of new measurements of the reaction rate constants for NO2 + OH + M and HNO3 + OH reduces the median chemical imbalance in the NOx budget for PEM-Tropics A from 2.4 to 1.9. The remaining imbalance cannot be easily explained from known chemistry or long-range transport of primary NOx and may imply a major gap in our understanding of the chemical cycling of NOx in the free troposphere. Copyright 2000 by the American Geophysical Union

Flexible Causal Inference for Political Science

Measuring the causal impact of state behavior on outcomes is one of the biggest methodological challenges in the field of political science, for two reasons: behavior is generally endogenous, and the threat of unobserved variables that confound the relationship between behavior and outcomes is pervasive. Matching methods, widely considered to be the state of the art in causal inference in political science, are generally ill-suited to inference in the presence of unobserved confounders. Heckman-style multiple-equation models offer a solution to this problem; however, they rely on functional-form assumptions that can produce substantial bias in estimates of average treatment effects. We describe a category of models, flexible joint likelihood models, that account for both features of the data while avoiding reliance on rigid functional-form assumptions. We then assess these models’ performance in a series of neutral simulations, in which they produce substantial (55% to 90%) reduction in bias relative to competing models. Finally, we demonstrate their utility in a reanalysis of Simmons’ (2000) classic study of the impact of Article VIII commitment on compliance with the IMF’s currency-restriction regime

Tracking mortality in near to real time provides essential information about the impact of the COVID-19 pandemic in South Africa in 2020

Background. Producing timely and accurate estimates of the impact of COVID-19 on mortality is challenging for most countries, but impossible for South Africa (SA) from cause-of-death statistics. Objectives. To quantify the excess deaths and likely magnitude of COVID-19 in SA in 2020 and draw conclusions on monitoring the epidemic in 2021. Methods. Basic details of deaths registered on the National Population Register by the Department of Home Affairs (DoHA) are provided to the South African Medical Research Council weekly. Adjustments are made to the numbers of weekly deaths to account for non-registration on the population register, as well as late registration of death with the DoHA. The weekly number of deaths is compared with the number predicted based on the Holt-Winters time-series analysis of past deaths for provinces and metropolitan areas. Excess deaths were calculated for all-causes deaths and natural deaths, using the predicted deaths as a baseline. In addition, an adjustment was made to the baseline for natural deaths to account for the drop in natural deaths due to lockdown. Results. We estimated that just over 550 000 deaths occurred among persons aged ≥1 year during 2020, 13% higher than the 485 000 predicted before the pandemic. A pronounced increase in weekly deaths from natural causes peaked in the middle of July across all ages except <20 years, and across all provinces with slightly different timing. During December, it became clear that SA was experiencing a second wave of COVID-19 that would exceed the death toll of the first wave. In 2020, there were 70 000 - 76 000 excess deaths from natural causes, depending on the base. Using the adjusted base, the excess death rate from natural causes was 122 per 100 000 population, with a male-to-female ratio of 0.78. Deaths from unnatural causes halved for both males and females during the stringent lockdown level 5. The numbers reverted towards the predicted number with some fluctuations as lockdown restrictions varied. Just under 5 000 unnatural deaths were averted. Conclusions. Tracking the weekly numbers of deaths in near to real time has provided important information about the spatiotemporal impact of the pandemic and highlights that the ~28 000 reported COVID-19 deaths during 2020 substantially understate the death toll from COVID-19. There is an urgent need to re-engineer the system of collecting and processing cause-of-death information so that it can be accessed in a timely way to inform public health actions