A parameterization of dust concentration (PM₁₀) of dust events observed at Erdene in Mongolia using the monitored tower data

Hourly mean time series of dust concentration (PM₁₀) measured at 3 m high and a sonic-anemometer measured momentum and kinematic heat fluxes at 8 m high above the surface have been obtained from a 20-m monitoring tower located at Erdene in the Asian dust source region of Mongolia for years of 2009 and 2010. These time series were used to identify dust events and to develop optimal regression equations for the dust concentration of dust events with the friction velocity (u_*) and the convective velocity scale (w_*). In total, 68 dust events were identified in 2009 (except for November) and 43 dust events for the period from March to August in 2010. The duration of each dust event ranged from 3-29 h in 2009 and 5-35 h in 2010. The maximum hourly mean dust concentration of the dust event was found to be 4,107 μg m^− 3 in May in 2009 and 4,708 μg m^− 3 in March in 2010 while a minimum of 251 μg m^− 3 in August in 2009 and 662 μg m^− 3 in June in 2010. The optimal regression equation for the dust concentration (C) of dust events was found to have the form of log C = a + b(u_* + cw_*)ⁿ, where a, b, c and n are constants that vary month to month. The convective velocity scale (w_*) that has not been taken into account in most dust modelings was found to enhance the dust concentration of dust events during the cold period from December to March when the soil temperature was below the freezing level for both the stable (w_* < 0) and unstable (w_* > 0) stratifications, whereas the convective velocity caused a reduction in the dust concentrations during the warm period from April to October, suggesting the importance of the convective velocity to estimate dust concentration of dust events.     

What do we know about effects of desert dust on air quality and human health in West Africa compared to other regions?

This study aims to compare, on the one hand, the geographical distribution of the desert dust source areas, their contribution to quantities emitted into the atmosphere, the trajectories and the quantities deposited, with on the other hand the areas of research interest focused on the desert dust impacts on air quality and/or human health. Based on a systematic review of the literature using the ISI Web of Knowledge database, we found 231 articles published over the last decade on the desert dust impacts on air quality. Of these, 48% concerned Asian dust and 39% Saharan dust, with the remaining 13% divided between the other dust source areas. However, only one of these studies addressed the worsening air pollution in West Africa, even though it is very close to the Sahara, the greatest contributor to the global dust budget. Moreover, there have been very few studies (41) looking at the direct links between desert dust and human health; in this context too, no interest has been shown in West Africa. Yet this region is also among the areas in which morbidity rates have been noted to be far higher than those found in other regions of the world, and where respiratory infections alone account for more than 20% of the causes of infant mortality. This survey highlights a clear imbalance between those areas most exposed to dust and the most studied areas in terms of dust impacts. Given these findings and the often alarming results published about other regions of the world, we advocate a revival of interest in research on West Africa in order to achieve a better understanding of the desert dust impacts on air quality and health among the populations of this region.     

Settling in or moving out? Exploring the effect of mobility intentions on public housing exits

This paper seeks to understand how public housing residents’ mobility intentions affect their actual exits. The results suggest that mobility intentions do have a significant effect on public housing exits. However, the rate of exit among those who intend to move out of public housing was similar to those who did not intend to leave. In addition, tenure had a significant effect on the odds of exiting alluding to issues of duration dependence. However, neighbourhood conditions did not fully explain public housing exits. Our proxy for policy reform had a large effect on the odds of exiting of public housing. This result suggests that changes in housing assistance programmes and urban housing policy could largely account for public housing exits. Overall, the results imply that while public housing residents may have positive and negative mobility intentions, their exits may primarily be due to shifts in housing policy and social welfare programmes versus individual characteristics and neighbourhood conditions.     

How effective has been the reduction of SO2 emissions on the effect of acid rain on ecosystems?

The paper attempts to assess the effectiveness of the reduction of SO2 emissions over recent years for protection of ecosystems in both Europe and eastern USA by analysis of temporal changes in the acidifying potential (AP) of wet deposition defined as [SO4(2-)] - ([Ca2+] + [Mg2+]). Spatial and temporal patterns of acidifying potential were studied. The main result is that there is no statistical evidence for a trend towards improvement in the acidifying potential, because there have been declines in Ca precipitation. This suggests that the reduction of SO2 emissions has not been effective as an abatement strategy.     

Does mercury interact with the inhibitory effect of dichlorvos on Palaemon serratus (Crustacea: Decapoda) cholinesterase?

Mercury is one of the most hazardous metals that may contaminate estuarine ecosystems and induce toxic effects on wildlife organisms. It has been suggested that impairment of cholinesterase (ChE) activity may be involved in the resulting mercury toxicity. Following Palaemon serratus exposure to mercury chloride (HgCl₂), no effect on ChE activity was observed whatever the concentration used (to 37.5 µM) or the time of exposure (to 7 days). By contrast, following 24 h exposure to dichlorvos, an organophosphate insecticide with a well-characterised anti-ChE action, decrease of ChE activity was observed until 30 to 40% basal activity, which seems to be the minimum activity required for prawn survival. In addition, HgCl₂ does not affect dichlorvos toxicity and treatments with a mixture of both compounds can be interpreted as the sum of the two independent toxicities. Therefore, mercury and insecticide toxicities are independent and ChE activity from P. serratus eyes seems to be a reliable and sensitive biomarker for organophosphate insecticides even when organisms are simultaneously exposed to mercury.     

Synergistic effect of nickel ions on the coupled dechlorination of trichloroethylene and 2,4-dichlorophenol by Fe/TiO₂ nanocomposites in the presence of UV light under anoxic conditions

The coupled removal of priority pollutants by nanocomposite materials has recently been receiving much attention. In this study, trichloroethylene (TCE) and 2,4-dichlorophenol (DCP) in aqueous solutions were simultaneously removed by Fe/TiO₂ nanocomposites under anoxic conditions in the presence of nickel ions and UV light at 365 nm. Both TCE and DCP were effectively dechlorinated by Fe/TiO₂ nanocomposites, and the pseudo-first-order rate constants (k_obs) for TCE and DCP dechlorination were (1.39 ± 0.05)×10⁻² and (1.08 ± 0.05)×10⁻² h⁻¹, respectively, which were higher than that by nanoscale zerovalent iron alone. In addition, the k_obs for DCP dechlorination was enhanced by a factor of 77 when Fe/TiO₂ was illuminated with UV light for 2 h. Hydrodechlorination was found to be the major reaction pathway for TCE dechlorination, while DCP could undergo reductive dechlorination or react with hydroxyl radicals to produce 1,4-benzoquinone and phenol. TCE was a stronger electron acceptor than DCP, which could inhibit the dechlorination efficiency and rate of DCP during simultaneous removal processes. The addition of nickel ions significantly enhanced the simultaneous photodechlorination efficiency of TCE and DCP under the illumination of UV light. The k_obs values for DCP and TCE photodechlorination by Fe/TiO₂ in the presence of 20-100 μM Ni(II) were 30.4-136 and 13.2-192 times greater, respectively, when compared with those in the dark. Electron spin resonance analysis showed that the photo-generated electron-hole pairs could be effectively separated through Ni ions cycling, leading to the improvement of electron transfer efficiency of TCE and DCP by Fe/TiO₂.     

Assessment of the effect of modern transformation on the traditional settlement ‘Ksar’ of Ouargla in southern Algeria

The architecture of the Ouargla Ksar has long been recognized as an example of adaptation to harsh climate in the deep desert of Algeria. Over the last few decades, it has undergone some changes in its initial urban structure, due to accelerated and uncontrolled modern urbanization, that had negative implications and devaluation of its thermal characteristics. This article tries to understand the bioclimatic concept of adaptation of this Ksar and assess to what extent its morphological transformation has impacted its microclimatic conditions. This assessment is made through a comparative study between two different areas: one untransformed and the other transformed. A referential weather station situated in the suburbs was also exploited for consolidation of comparison. The investigation was undertaken using site measurements and observations.     

Is ecosystem structure the target of concern in ecological effect assessments?

The species sensitivity distribution, a technique currently used to derive water-quality standards of chemicals, is associated with a set of inadequately tested assumptions. One of these assumptions is that ecosystem structure is as or more sensitive than ecosystem function, i.e., that structure is the target of concern. In this paper, we tested this assumption for a simple freshwater ecosystem exposed to different toxicants. Using an ecosystem model, we calculated no observed effect concentrations (NOECs) for ecosystem structure (ecosystem structure-NOECs) and function (ecosystem function-NOECs) for each of 1000 hypothetical toxicants. For 979 of these toxicants, the ecosystem structure-NOEC was lower than or equal to the ecosystem function-NOEC, indicating that the tested assumption can be considered valid. For 239 of these 979 toxicants, both NOECs were equal. For half of the 1000 toxicants, the structure of lower trophic levels (i.e., phytoplankton) appears to be more sensitive than the structure of higher trophic levels (i.e., fish). As such, ecosystem structure-NOECs are primarily determined by the sensitivity of the structure of lower trophic levels. In contrast, ecosystem functions associated with higher trophic levels (e.g., total ingestion by fish) are more sensitive than functions associated with lower trophic levels (e.g., total photosynthesis by phytoplankton) for 749 toxicants.     

‘The Congo must have a presence on Belgian soil.‘ The concept of representation in governmental discourses on the architecture of the Ministry of Colonies in Brussels, 1908–1960

While parliament buildings and governor‘s palaces have been studied as embodiments of governmental or colonial power, the architecture of the often more mundane state administrative office buildings has only received scant attention from architectural historians. In this article, we seek to demonstrate that political discourses concerning such buildings can nonetheless reveal important conceptions of colonial power. Rather than focussing on how such power was accommodated in and shaped by state-built architecture overseas, this article draws attention to the representational aspects of colonial governance in a mother country through an analysis of various projects proposed for the Belgian Ministry of Colonies (1908–1960). In the 1930s, when it was still housed in an eighteenth-century neoclassical building in Brussels, the Ministry of Colonies was included in a visionary but unsuccessful civil service reform, which was aimed at a modernisation of the Belgian state bureaucracy and its office buildings. After the Second World War, when colonialism became increasingly criticised in international fora, successive Belgian Ministers of Colonies pleaded for the construction of a new, grandiose ministerial complex, which was supposed to symbolise efficiency, modernity, and—above all —the permanence of the colonial undertaking. Even though important steps were taken to realise this complex, the project was outrun by the global decolonisation process, of which the independence of the Belgian Congo (1960) was an inevitable outcome.     

Does Place Matter? The Effects of Concentrated Poverty on the Computer Use of Elementary Students

For several decades, scholars have investigated technological inequality within American society. These studies have focused on individual-level predictors of computer use such as income, education, and technological skills. Although these individual-level inequities are important contributors of technological inequalities, they neglect the importance of place, including neighborhood-level factors such as median income, racial composition, and educational attainment. The purpose of this study is to address this gap in the current literature by examining neighborhood-level effects of concentrated poverty on the trajectory of computer use (the change in computer use over a one-year period). Data were collected from fourth and fifth grade classrooms from two data points in a public school district in a mid-sized city in the southeastern United States. Results indicate that measures of concentrated poverty have an influence on the trajectory of computer use among elementary students. These findings suggest that social inequalities at the neighborhood level need to be addressed to further eliminate the digital divide in computer use among elementary students.     

Does spatial configuration matter? Understanding the effects of land cover pattern on land surface temperature in urban landscapes

The effects of land cover composition on land surface temperature (LST) have been extensively documented. Few studies, however, have examined the effects of land cover configuration. This paper investigates the effects of both the composition and configuration of land cover features on LST in Baltimore, MD, USA, using correlation analyses and multiple linear regressions. Landsat ETM + image data were used to estimate LST. The composition and configuration of land cover features were measured by a series of landscape metrics, which were calculated based on a high-resolution land cover map with an overall accuracy of 92.3%. We found that the composition of land cover features is more important in determining LST than their configuration. The land cover feature that most significantly affects the magnitude of LST is the percent cover of buildings. In contrast, percent cover of woody vegetation is the most important factor mitigating UHI effects. However, the configuration of land cover features also matters. Holding composition constant, LST can be significantly increased or decreased by different spatial arrangements of land cover features. These results suggest that the impact of urbanization on UHI can be mitigated not only by balancing the relative amounts of various land cover features, but also by optimizing their spatial configuration. This research expands our scientific understanding of the effects of land cover pattern on UHI by explicitly quantifying the effects of configuration. In addition, it may provide important insights for urban planners and natural resources managers on mitigating the impact of urban development on UHI.     

Does the triad of fungi,bacteria and exposure to moisture have an impact on chronic hyperplastic sinusitis?

Here we evaluated a possible relationship between chronic hyperplastic sinusitis (CHS) and moisture exposure and secondly a seasonal variation of fungal and bacterial findings in the healthy nose. In 28 CHS patients sinus mucus was collected during endoscopic sinus surgery. Samples from the nasal cavities of 19 healthy volunteers were collected by nasal lavage (NAL) in January and in September. Bacterial culture and fungal staining and culture were carried out. Histological samples from the sinus mucosa were obtained. Patients' medical history and environmental factors were enquired. Mold odor or moisture problems in the home or work environment were reported by 46% of the CHS patients. Patients who reported moisture exposure did not differ significantly from those who had not been exposed with regards to microbiological findings, tissue eosinophilia, and earlier operations. Cladosporium (16%) and Alternaria (11%) were found in NAL fluid collected in the autumn from the control subjects. No fungi were isolated from samples taken during the winter. An association between CHS or fungal sinusitis and moisture damage was not apparent in the present study. The fungal findings in the nasal cavity reflect the environmental exposure. This should be taken into account when NAL is used for microbiological studies. PRACTICAL IMPLICATIONS: Living in a moldy house or working in a similar environment may increase the risk of respiratory symptoms and infections. However, our results suggest that chronic hyperplastic sinusitis and fungal sinusitis are not associated with moisture exposure. The nose is a good collector of particles in the air. Especially samples taken by the nasal lavage method reflect the environmental exposure. This should be taken into account when this method is used for microbiological studies.     

Does the smartest designer design better? Effect of intelligence quotient on students’ design skills in architectural design studio

Understanding the cognitive processes of the human mind is necessary to further learn about design thinking processes. Cognitive studies are also significant in the research about design studio. The aim of this study is to examine the effect of designers intelligence quotient(IQ) on their designs. The statistical population in this study consisted of all Deylaman Institute of Higher Education architecture graduate students enrolled in 2011. Sixty of these students were selected via simple random sampling based on the finite population sample size calculation formula. Thestudents’ IQ was measured using Raven’s Progressive Matrices. The students’ scores in Architecture Design Studio (ADS)courses from first grade(ADS-1) to fifth grade (ADS-5) and the mean scores of the design courses were used in determining the students’ design ability. Inferential statistics, as well as correlation analysis and mean comparison test for independent samples with SPSS, were also employed to analyze the research data. Results indicated that the students’ IQ, ADS-1 to ADS-4 scores, and the mean scores of the students’ design courses were not significantly correlated. By contrast, the students’ IQ and ADS-5 scores were significantly correlated. As the complexity of the design problem and designers’ experience increased, the effect of IQ on design seemingly intensified.     

Does the ethnic gap in homeownership vary by income? An analysis on Dutch survey data

Lower levels of homeownership among immigrant populations have frequently been related to the particular financial constraints that immigrant households can face. Various problems have been raised with this explanation for the ethnic gap in homeownership rates. This paper responds to these criticisms by sensitizing the financial constraints explanation to the possibility of differential effects of ethnicity depending upon level of income. The hypothesis that the ethnic gap is stronger for lower income groups is tested through logistic analyses of the housing tenure of Turkish and Moroccan immigrants and a comparison group of native citizens in the Netherlands. High-income Turks are revealed to have comparable rates of homeownership to high-income natives, whereas in low-income groups a large ethnic gap exists. The ethnic gap in homeownership among low-income groups could not be explained by other financial constraints (education, couple’s earning status, parental resources). Housing preferences and discrimination are possible explanations for this ethnic gap among low-income households.     

Explaining and evaluating the quality of “light” in religious environments and its effect on spirituality

The current study aimed to investigate the quality of the interior architecture of the religious spaces regarding inducing the sense of spirituality with an emphasis on light. Thus, the authors introduced the best option by simulating the light intensity of the interior environment of the Nasir Al-Mulk Mosque, Shiraz, in software and developing a visual standard questionnaire with a statistical population including the experts. This research was a field, and survey study and computational software were used to simulate the light intensity of the interior environment of the mosque in the first part. Then, the researcher-made visual questionnaire was developed. Also, this questionnaire was sent to the experts online due to the current situations due to the Covid-19 pandemic. The statistical population was selected using the purposive sampling method from the universities of Iran, Malaysia, India, and Turkey, whose expertise was architecture, environmental psychology, and sacred arts.     

Does the tender,auction and listing system in land promote higher housing prices in China?

Using monthly data on national housing prices from July 1998 to June 2015, we investigate the effect of the ‘Tender, Auction and Listing’ (hereafter TAL) system on housing prices in land, implemented on 31 August 2004. We apply the additional polynomial regression discontinuity method which effectively eliminates the effects of several confounding factors such as financial crisis, ‘New National Ten Provisions’ and ‘9.30 New Regime’. We find that, although the TAL has caused the national average housing prices to go up by 10%, accounting for 11% of total increase in housing prices in the last year, it does not constitute the major driver for housing prices. Furthermore, our results indicate that TAL has exerted a larger impact on commercial and residential properties, especially in the middle and west regions. By examining the transmission mechanisms, we find that the effects of TAL are mainly via government’s starvation-style land supply effect and market-reshuffling effect.     

Assessing the impact of international development policies on the process of civil society participation in urban development in the countries of the South: the case of Syria, 2005–2010

This paper seeks to explore the effect of the international development policies promoted by the United Nations Development Programme on civil society participation in urban development process in the countries of the South. More specifically, the case of Syria during the period 2005–2010 was examined. An institutional analysis was conducted in order to investigate the question of whether development institutions in particular contexts, in terms of both the mental models and the organizational forms of development, permitted the space needed to apply this principle in practice. In this, the paper argues the need to promote a proactive approach to enable civil society participation in the countries of the South rather than a normative internationally accepted approach developed in isolation from the given political and institutional context.     

Does wage differential driven migration continue to exist? Tests on the role of regional economic structure in wage differential driven migration

This paper explores the role of regional economic structure in the wage differential driven migration among the US Metropolitan Statistical Areas for three discrete time periods from 1993 to 2004. Rapidly increasing interregional trade attributes to the restructuring process of production internationally and interregionally. Both trade and migration can contribute to the equilibrium conditions in regional labor markets. When fragmentation increases intra-industry trade (IIT) in interregional trade, do we expect to see the increasing roles of interregional trade toward the equilibrium condition in regional labor markets? Fragmentation may force some production stages to the other regions, in other words, firms may benefit from relocating to the regions where they can minimize labor costs with cheaper wage rates. In this restructuring process, similarities in regional economic structures may increase the volumes of IIT and as a result, we may expect to see the increasing complementary role of trade in factor price equalization to migration. In contrast, when regional economic structures are quite different, migration rather than trade plays more important role in factor price equalization. Consequently, the main flows of interregional migration caused by wage differentials are more likely to be found among the regions where regional economic structures are dissimilar.     

Impacts of risk allocation on conflict negotiation costs in construction projects: Does managerial control matter?

The negotiation costs for project participants to resolve conflicts significantly undermine the project performance, but how to reduce these costs remains largely unexplored. This study proposes that risk allocation in the contract between the client and contractor will impact the conflict negotiation costs and managerial controls of the client will moderate this relationship. Hypotheses were tested with a sample of 226 projects collected from Chinese construction firms. The results show that conflict negotiation costs will increase with more risks allocated to the contractor. Moreover, behavior control of the client strengthens this positive relationship but outcome control weakens it. These findings offer a nuanced understanding of how conflict negotiation costs occur and contribute to the project governance literature by exploring how ex-post governance (managerial control) aligns with ex-ante governance (risk allocation). Practitioners can benefit from this study by understanding how to formulate risk allocation strategies and exercise different managerial controls.