Search

ABSTRACTWhile housing affordability is well documented for developed countries, we still lack systematic analyses and cross-city comparisons for developing countries. This paper aims to contribute to the relevant literature by comparatively analyzing city-level housing unaffordability of 211 cities in 27 developing countries located in the Asia-Pacific region. The average price-to-income ratio (PIR) for our sample is above 12.5, which indicates that housing is severely unaffordable for the large majority of urban dwellers in developing Asia. Using a regression-based approach, we find evidence that the housing unaffordability tends to increase for cities with larger population and lower household income. Our results also demonstrate that the extent of housing unaffordability in developing Asia is substantially higher compared with cities in developed countries. Potential reasons include slower supply responses, lower household income spent on housing, relatively higher construction costs, rigid land use regulations and inefficient planning systems. If housing remains out of reach for in-migrants and newly formed households in most existing urban areas of developing countries, their potential of further urbanization and economic growth is likely to be undermined.HighlightsWe study housing affordability in 211 cities in 27 developing countries in the Asia-Pacific region.The average price-to-income ratio is above 12.5, indicating that housing is severely unaffordable for the large majority of urban dwellers.Housing unaffordability tends to increase for cities with larger population and lower household income.The extent of housing unaffordability in developing Asia is substantially higher compared with cities in developed countries.Potential reasons for housing unaffordability include slower supply responses, lower household income spent on housing, relatively higher construction costs, rigid land use regulations and inefficient planning systems.

Bacterial glycans contain rare, exclusively bacterial monosaccharides that are frequently linked to pathogenesis and essentially absent from human cells. Therefore, bacterial glycans are intriguing molecular targets. However, systematic discovery of bacterial glycoproteins is hampered by the presence of rare deoxy amino sugars, which are refractory to traditional glycan-binding reagents. Thus, the development of chemical tools that label bacterial glycans is a crucial step toward discovering and targeting these biomolecules. Here, we explore the extent to which metabolic glycan labeling facilitates the studying and targeting of glycoproteins in a range of pathogenic and symbiotic bacterial strains. We began with an azide-containing analog of the naturally abundant monosaccharide N-acetylglucosamine and discovered that it is not broadly incorporated into bacterial glycans, thus revealing a need for additional azidosugar substrates to broaden the utility of metabolic glycan labeling in bacteria. Therefore, we designed and synthesized analogs of the rare deoxy amino d-sugars N-acetylfucosamine, bacillosamine, and 2,4-diacetamido-2,4,6-trideoxygalactose and established that these analogs are differentially incorporated into glycan-containing structures in a range of pathogenic and symbiotic bacterial species. Further application of these analogs will refine our knowledge of the glycan repertoire in diverse bacteria and may find utility in treating a variety of infectious diseases with selectivity.

IPI‐504 (retaspimycin hydrochloride) is an Hsp90 inhibitor that is the subject of multiple clinical trials for the treatment of cancer. IPI‐504 is an aqueous soluble (>200 mg/ml) hydroquinone hydrochloride salt of 17‐(allylamino)‐17‐demethoxygeldanamycin (17‐AAG), a quinone derivative also undergoing clinical evaluation, albeit with suboptimal formulations that address its inferior aqueous solubility (∼50 µg/ml). IPI‐504 interconverts with 17‐AAG in vivo through oxidation‐reduction reactions that result in a dynamic redox equilibrium. The development challenges associated with redox active molecules are significant due to the pH, oxygen, and temperature sensitivities associated with such chemotypes. The API and sterile drug product manufacturing processes thus warrant the monitoring and control of these key variables. Furthermore, the pharmaceutical development challenges associated with cancer agents that are often fast‐tracked due to unmet medical needs mandate a rapid development cycle with associated regulatory hurdles. Drug Dev Res 71: 429–438, 2010. © 2010 Wiley‐Liss, Inc.

Liquid amines can be immobilized within the pores of polymeric supports to provide a regenerable CO2 sorbent. This paper describes the capture of CO2 by a range of ethanolamines (primary, secondary, and tertiary) immobilized within the pores of high-surface-area poly(methyl methacrylate) beads. These supported amines were used to remove low concentrations (7.6 mmHg) of CO2 by a pressure swing absorption process, where low-pressure vacuum was used to desorb the CO2 and regenerate the sorbent. The effect on CO2 capture of modification of primary amines to secondary amines by reaction with acrylonitrile was also evaluated. The modified amines provided nearly a factor of 2 increase in CO2 removal capacity compared to the original primary amines. These results suggest that modified amines could potentially be used for CO2 capture in space life support systems as well as for terrestrial flue gas CO2 removal applications.

A model is presented for coalescence by viscous flow in two-particle systems, a phenomenon of interest in such diverse processes as the coagulation of air pollutant aerosols, glass and polymer sintering, and the coagulation of liquid suspensions. The model achieves computational efficiency by incorporating an empirical analytical function to describe the fluid interface, making it particularly suited to incorporation into aerosol dynamics models under conditions where coalescence-limited growth can occur. The dynamics of the interfacial evolution in the coalescing pair are approximated by employing a modification to the boundary integral approach in which a single surface point is used to solve the equations for the surface velocities. Model predictions of dimensionless shrinkage and neck growth obtained using this modeling approach compare favorably to those of existing finite-element models reported in the literature and provide a basis for more complex models to approximate multiple particle coalescence.

This paper deals with reasons and consequences of scientific failure: When do we talk of «failure» in science? How definite is desaster in experiments? Can we characterize a certain type of scientist who might be bound to fail? How do scienists try to avoid getting defeated and how do they manage to get up again if they were? What will happen to the forework of a lost project? Will it be lost, too? What will happen to the forethoughts, to the scientist’s intentions, what will happen to his hopes? Do we actually need to prevent it by any means and to reveal any moment it has happened? Perhaps, there might be a creative potential hidden in situations of failure, an additional painful motivation deriving from being left with one’s mere honesty as a researcher in absence of honours as a successful finder. Perhaps, the very moment of failure is just the one to discover one’s identity as a scientist, having worked for nothing than the simple truth of error. Perhaps, failure is one of the greatest chances scientists have.

Many animals rely on long-form communication, in the form of songs, for vital functions such as mate attraction and territorial defence. We explored the prospect of improving automatic recognition performance by using the temporal context inherent in song. The ability to accurately detect sequences of calls has implications for conservation and biological studies. We show that the performance of a convolutional neural network (CNN), designed to detect song notes (calls) in short-duration audio segments, can be improved by combining it with a recurrent network designed to process sequences of learned representations from the CNN on a longer time scale. The combined system of independently trained CNN and long short-term memory (LSTM) network models exploits the temporal patterns between song notes. We demonstrate the technique using recordings of fin whale (Balaenoptera physalus) songs, which comprise patterned sequences of characteristic notes. We evaluated several variants of the CNN + LSTM network. Relative to the baseline CNN model, the CNN + LSTM models reduced performance variance, offering a 9–17% increase in area under the precision–recall curve and a 9–18% increase in peak F1-scores. These results show that the inclusion of temporal information may offer a valuable pathway for improving the automatic recognition and transcription of wildlife recordings.

The time resolved evolution of ash during the combustion of individual char particles has been studied using a Montana lignite, a North Dakota Beulah lignite, and a synthetic char prepared from doped sucrose. The three chars were selected to illustrate the effects of macroporosity and mineral matter content on the ash evolution. The synthetic char is distinguished from the lignites by being macropore-free. The ash content was varied from 17%(Montana) to 37%(Beulah). When the chars are reacted under external-diffusion-controlled conditions, the mineral matter is released as the carbon surface recedes. The ash particles on the surface of the char aggregate and grow in size with increasing char burnout. The rate of growth of particle size increases markedly as the extent of burnout increases because of the increase in surface concentration of released ash. The ash sizes are larger for the char with the higher mineral content. As complete burnout is approached, however, the macroporous lignite chars fragment yielding smaller final ash particles than the macropore-free sucrose char. A percolation model applied to the ash formation processes was used to demonstrate the major features of the dependence of the time resolved evolution of ash on macroporosity.

Ash formation during pulverized coal combustion has been simulated using a Monte Carlo model to follow the ash coalescence and char fragmentation processes that govern the final particle size distribution. As a consequence of the competition between the particle breakup by fragmentation and the ash coalescence enhanced by the shrinking peripheral area with the progress of char reaction, a bimodal size distribution is obtained. A simplified two-column model is also presented in order to explain the influence of the ash redistribution scheme used in the model on the evolution of the bimodality.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has caused a global pandemic of COVID-19, resulting in cases of mild to severe respiratory distress and significant mortality. The global outbreak of this novel coronavirus has now infected >20 million people worldwide, with >5 million cases in the United States (11 August 2020). The development of diagnostic and research tools to determine infection and vaccine efficacy is critically needed.

Chlamydia trachomatisis an important mucosal pathogen that is the leading cause of sexually transmitted bacterial infections in the United States. Despite this, there is no vaccine currently available. In order to develop such a vaccine, it is necessary to understand the components of the immune response that can lead to protection against this pathogen. It is well known that antigen-specific CD4+T cells are critical for Chlamydiaclearance, but the contexts in which they are protective or not protective are unknown. Here, we aimed to characterize the importance of gamma interferon production and sensing by T cells and the effects on the immune response to C. trachomatis. Our work here helps to define the contexts in which antigen-specific T cells can be protective, which is critical to our ability to design an effective and protective vaccine against C. trachomatis.

Chlamydia trachomatisis the most commonly reported bacterial sexually transmitted infection in the United States. Modeling infection in animals can be challenging, as mice naturally clear C. trachomatiswhen it is deposited in the lower genital tract. However, C. trachomatiscan productively infect mice when the lower genital tract is bypassed and bacteria are deposited directly into the upper genital tract via transcervical inoculation.

Antigen-specific CD4+T cells against Chlamydiaare crucial for driving bacterial clearance and mediating protection against reinfection. Although the Chlamydia trachomatisprotein Cta1 has been identified to be a dominant murine CD4+T cell antigen, its level of expression during the bacterial developmental cycle and precise localization within the host cell are unknown.

The article presents information regarding opportunities for the students to stretch the limits of their knowledge of their discipline.