The re-urbanization of the city center of Manaus , Brazil - Facing the challenges of informal settlements

Illegal occupation of urban land in Brazil is a widespread phenomenon. Slum dwellers are excluded from the attributes of urban citizenship although they provide the labor force required by low productivity urban services needed by cities. Illegal settlements generate multiple problems for the rest of the city . Its solution is of key relevance to the city in general but also provide an opportunity for the social and economic advancement of slum dwellers. The programs required to attain these results are complex and difficult to implement underscoring the challenges countries will face to attain the Millennium Development Goals of reducing the population living in slums.

Spatial mapping of city-wide PBDE levels using an exponential decay model

Passive air samplers (PAS) consisting of polyurethane foam (PUF) disks were deployed at 6 outdoor air monitoring stations in different land use categories (commercial, industrial, residential and semi-rural) to assess the spatial distribution of polybrominated diphenyl ethers (PBDEs) in the Brisbane airshed. Air monitoring sites covered an area of 1143 km2 and PAS were allowed to accumulate PBDEs in the city's airshed over three consecutive seasons commencing in the winter of 2008. The average sum of five (∑5) PBDEs (BDEs 28, 47, 99, 100 and 209) levels were highest at the commercial and industrial sites (12.7 ± 5.2 ng PUF−1), which were relatively close to the city center and were a factor of 8 times higher than residential and semi-rural sites located in outer Brisbane. To estimate the magnitude of the urban ‘plume’ an empirical exponential decay model was used to fit PAS data vs. distance from the CBD, with the best correlation observed when the particulate bound BDE-209 was not included (∑5-209) (r2 = 0.99), rather than ∑5 (r2 = 0.84). At 95% confidence intervals the model predicts that regardless of site characterization, ∑5-209 concentrations in a PAS sample taken between 4–10 km from the city centre would be half that from a sample taken from the city centre and reach a baseline or plateau (0.6 to 1.3 ng PUF−1), approximately 30 km from the CBD. The observed exponential decay in ∑5-209 levels over distance corresponded with Brisbane's decreasing population density (persons/km2) from the city center. The residual error associated with the model increased significantly when including BDE-209 levels, primarily due to the highest level (11.4 ± 1.8 ng PUF−1) being consistently detected at the industrial site, indicating a potential primary source at this site. Active air samples collected alongside the PAS at the industrial air monitoring site (B) indicated BDE-209 dominated congener composition and was entirely associated with the particulate phase. This study demonstrates that PAS are effective tools for monitoring citywide regional differences however, interpretation of spatial trends for POPs which are predominantly associated with the particulate phase such as BDE-209, may be restricted to identifying ‘hotspots’ rather than broad spatial trends.

Understanding Density in an Uneven City, Santiago de Chile: Implications for Social and Environmental Sustainability

Efforts to promote infill development and to raise densities are growing in many cities around the world as a way to encourage urban sustainability. However, in cities polarized along socio-economic lines, the benefits of densification are not so evident. The aim of this paper is to discuss some of the contradictions of densification in Santiago de Chile, a city characterized by socio-spatial disparities. To that end, we first use regression analysis to explain differences in density rates within the city. The regression analysis shows that dwelling density depends on the distance from the city center, socioeconomic conditions, and the availability of urban attributes in the area. After understanding the density profile, we discuss the implications for travel and the distribution of social infrastructures and the environmental services provided by green areas. While, at the metropolitan scale, densification may favor a more sustainable travel pattern, it should be achieved by balancing density rates and addressing spatial differences in the provision of social services and environmental amenities. We believe a metropolitan approach is essential to correct these spatial imbalances and to promote a more sustainable and socially cohesive growth pattern.

Urban heat island and wind flow characteristics of a tropical city

 Urban Heat Island (UHI) has become a growing concern to the quality of densely built urban environments, particularly in tropical cities. Wind speed has widely been reported to have decreased the intensity of heat island effect in urban areas. The cooling effect of the wind helps to mitigate the adverse effects of heat island on the micro climate and human thermal comfort. This paper investigates the existence of heat island in Muar, one of the fast growing cities in southern part of Malaysia and its possible causes, and then examines the effects of different urban geometry on the wind flow. The results of this study indicate that the chaotic development in Muar has caused reduced ventilation in urban canyons. The heat island intensity in the city center was recorded as 4. °C during the day and 3.2. °C during the night. Investigation of various urban geometry modifications showed that step up configuration was the most effective geometry as it can distribute the wind evenly allowing the wind to reach even the leeward side of each building. © 2014 Elsevier Ltd.

The impact of atmospheric particulate matter on cancer incidence and mortality in the city of Sao Paulo, Brazil

This study aimed to verify the impact of inhalable particulate matter (PM10) on cancer incidence and mortality in the city of Sao Paulo, Brazil. Statistical techniques were used to investigate the relationship between PM10 on cancer incidence and mortality in selected districts. For some types of cancer (skin, lung, thyroid, larynx, and bladder) and some periods, the correlation coefficients ranged from 0.60 to 0.80 for incidence. Lung cancer mortality showed more correlations during the overall period. Spatial analysis showed that districts distant from the city center showed higher than expected relative risk, depending on the type of cancer According to the study, urban PM10 can contribute to increased incidence of some cancers and may also contribute to increased cancer mortality. The results highlight the need to adopt measures to reduce atmospheric PM10 levels and the importance of their continuous monitoring.

The impact of atmospheric particulate matter on cancer incidence and mortality in the city of São Paulo, Brazil

This study aimed to verify the impact of inhalable particulate matter (PM10) on cancer incidence and mortality in the city of São Paulo, Brazil. Statistical techniques were used to investigate the relationship between PM10 on cancer incidence and mortality in selected districts. For some types of cancer (skin, lung, thyroid, larynx, and bladder) and some periods, the correlation coefficients ranged from 0.60 to 0.80 for incidence. Lung cancer mortality showed more correlations during the overall period. Spatial analysis showed that districts distant from the city center showed higher than expected relative risk, depending on the type of cancer. According to the study, urban PM10 can contribute to increased incidence of some cancers and may also contribute to increased cancer mortality. The results highlight the need to adopt measures to reduce atmospheric PM10 levels and the importance of their continuous monitoring.

A youth vision of the city: The socio-spatial lives and exclusion of street girls in Bogota, Colombia

This dissertation documents the everyday lives and spaces of a population of youth typically constructed as out of place, and the broader urban context in which they are rendered as such. Thirty-three female and transgender street youth participated in the development of this youth-based participatory action research (YPAR) project utilizing geo-ethnographic methods, auto-photography, and archival research throughout a six-phase, eighteen-month research process in Bogotá, Colombia. ^ This dissertation details the participatory writing process that enabled the YPAR research team to destabilize dominant representations of both street girls and urban space and the participatory mapping process that enabled the development of a youth vision of the city through cartographic images. The maps display individual and aggregate spatial data indicating trends within and making comparisons between three subgroups of the research population according to nine spatial variables. These spatial data, coupled with photographic and ethnographic data, substantiate that street girls’ mobilities and activity spaces intersect with and are altered by state-sponsored urban renewal projects and paramilitary-led social cleansing killings, both efforts to clean up Bogotá by purging the city center of deviant populations and places. ^ Advancing an ethical approach to conducting research with excluded populations, this dissertation argues for the enactment of critical field praxis and care ethics within a YPAR framework to incorporate young people as principal research actors rather than merely voices represented in adultist academic discourse. Interjection of considerations of space, gender, and participation into the study of street youth produce new ways of envisioning the city and the role of young people in research. Instead of seeing the city from a panoptic view, Bogotá is revealed through the eyes of street youth who participated in the construction and feminist visualization of a new cartography and counter-map of the city grounded in embodied, situated praxis. This dissertation presents a socially responsible approach to conducting action-research with high-risk youth by documenting how street girls reclaim their right to the city on paper and in practice; through maps of their everyday exclusion in Bogotá followed by activism to fight against it.^

Tourism Impacts of a Portuguese World Heritage Historic Center: Residents’ Perspectives

The World Heritage List (WHL) is widely considered a powerful tool for national tourism campaigns. Sites inscribed on the WHL by the United Nations Educational, Scientific, and Cultural Organization (UNESCO) are commonly treated as catholicons in promoting the tourism industry, which in turn helps to promote economic growth and development. This study analyzes local community perceptions of the importance of the World Heritage Site (WHS) classification of the historic center of the Portuguese city of E ́vora. The research also includes an analysis of the local residents’ perceived tourism impacts on the municipality of E ́ vora. The methodology consists of quan- titative research based on a self-administered survey applied to convenience sam- ples of local residents of the municipality of E ́ vora in the beginning of 2014. The local residents’ perceptions of the level of importance of the WHS classification to the municipality and its impact in the increase of tourists is analyzed. Positive and negative tourism impacts are then ranked and a principal components factor analysis is employed separately to the two groups of impacts in order to identify underlying dimensions associated with residents’ perceptions on tourism develop- ment. Based on the results of the factor analysis, independent sample t-tests are used to investigate differences regarding positive and negative tourism impacts between residents that live near and far from the historic center, and between residents who work/have worked in the tourism sector and residents that work/ have worked in other sectors.

Intra urban air temperature distributions in historic urban center

The study investigates the urban heat island effect in Malaysian historic town Malacca through seven mobile traverses, as carried out on 10 December 2011. It aims to identify the intra-urban air temperature differences between heritage core zone, new development area and outskirts of the city. Air temperature variations were also analyzed across three different zones; namely the outskirts, the heritage site and the city center district. Heat index values were then calculated based on air temperature and relative humidity to gauge the level of outdoor thermal comfort within the study area. Based on the indications, one may conclude that the heritage place’s core zone is currently threatened by escalating temperatures and that its current temperature range falls within the “caution” and “extreme caution” categories. Furthermore, no significant difference was observed between the peak temperatures of the old city quarters and newer areas; despite the disparities in their urban forms. Therefore, it is hoped that the study, with its implications, will be able to influence future environmental consideration in heritage city of Melaka.

Cities and the Night-time Economy

Reports on the reemergence of a concern with planning city centers as focal points in the 1980s. De-industrialization of older industrial areas; Revalorization of city center sites; Emergence of city-to-city competitiveness at a national and supranational level.

Energy-efficient virtual machine placement in data centers by genetic algorithm

Server consolidation using virtualization technology has become an important technology to improve the energy efficiency of data centers. Virtual machine placement is the key in the server consolidation. In the past few years, many approaches to the virtual machine placement have been proposed. However, existing virtual machine placement approaches to the virtual machine placement problem consider the energy consumption by physical machines in a data center only, but do not consider the energy consumption in communication network in the data center. However, the energy consumption in the communication network in a data center is not trivial, and therefore should be considered in the virtual machine placement in order to make the data center more energy-efficient. In this paper, we propose a genetic algorithm for a new virtual machine placement problem that considers the energy consumption in both the servers and the communication network in the data center. Experimental results show that the genetic algorithm performs well when tackling test problems of different kinds, and scales up well when the problem size increases.

A cryptographic analysis of the TLS 1.3 handshake protocol candidates

The Internet Engineering Task Force (IETF) is currently developing the next version of the Transport Layer Security (TLS) protocol, version 1.3. The transparency of this standardization process allows comprehensive cryptographic analysis of the protocols prior to adoption, whereas previous TLS versions have been scrutinized in the cryptographic literature only after standardization. This is even more important as there are two related, yet slightly different, candidates in discussion for TLS 1.3, called draft-ietf-tls-tls13-05 and draft-ietf-tls-tls13-dh-based. We give a cryptographic analysis of the primary ephemeral Diffie–Hellman-based handshake protocol, which authenticates parties and establishes encryption keys, of both TLS 1.3 candidates. We show that both candidate handshakes achieve the main goal of providing secure authenticated key exchange according to an augmented multi-stage version of the Bellare–Rogaway model. Such a multi-stage approach is convenient for analyzing the design of the candidates, as they establish multiple session keys during the exchange. An important step in our analysis is to consider compositional security guarantees. We show that, since our multi-stage key exchange security notion is composable with arbitrary symmetric-key protocols, the use of session keys in the record layer protocol is safe. Moreover, since we can view the abbreviated TLS resumption procedure also as a symmetric-key protocol, our compositional analysis allows us to directly conclude security of the combined handshake with session resumption. We include a discussion on several design characteristics of the TLS 1.3 drafts based on the observations in our analysis.

Helsingin kävelykeskustan suunnittelu ydinkeskustan kadunvarsiliikeyrittäjien näkökulmasta

Aiempien tutkimusten mukaan keskustayrittäjien kielteinen asenne on olennaisesti vaikeuttanut kävelykatujen toteuttamista kaupunkikeskustoissa. Yrittäjät pelkäävät ostokykyisten asiakkaiden kaikkoavan ja liikevaihtonsa pienenevän kävelykeskustauudistusten myötä. Yrittäjien kielteiset asenteet ovat usein myös painottuneet suuriin kaupunkeihin. Etenkin ydinkeskustassa sijaitsevat kadunvarsiliikeyrittäjät ovat kokeneet kävelykadut ongelmiksi. Tämän tutkimuksen tavoitteena on selvittää, mikä on ydinkeskustan kadunvarsiliikeyrittäjien näkemys Helsingin kävelykeskustan suunnittelusta, millaisena ydinkeskustan kadunvarsiliikeyrittäjät näkevät sijaintikatunsa kävelykeskustan suunnittelupäämäärien kautta tarkasteltuna, ja onko kävelykatuyrittäjien ja kävelykatujen ulkopuolella sijaitsevien yrittäjien näkemysten välillä eroja. Taustana tälle tarkastellaan Helsingin kävelykeskustaa pohjoismaisessa kontekstissa, ja käydään läpi Helsingin kävelykeskustan suunnittelun ja rakentumisen historiaa ja päämääriä. Tutkimuksen aineisto koostuu Helsingin ydinkeskustan kadunvarsiliikeyrittäjille tehdystä kyselystä, kävelykeskustoihin liittyvistä tutkimuksista ja selvityksistä, kaupunkisuunnitteluun ja -tutkimukseen liittyvästä tutkimuskirjallisuudesta, sanomalehtiartikkeleista, ydinkeskustassa tehdystä empiirisestä havainnoinnista ja kahdesta asiantuntijahaastattelusta. Kyselyaineistoa analysoidaan tutkimuksessa tilastollisten menetelmien avulla. Helsingin kävelykeskustan suunnittelu ja rakentuminen on ollut pitkällinen prosessi. Vuoden 1 989 kävelykeskustan periaatesuunnitelmasta on konkretisoitunut Kluuvikatu ja Mikonkatu. Keskustatunnelihanke on vaakalaudalla, minkä vuoksi kävelykeskustan uuden periaatesuunnitelman toteutuminen on epävarmaa. Kävelykeskustan rakentuminen kuitenkin etenee. Keskuskatu ja Kalevankadun itäpää muutetaan kävelykaduiksi ja ydinkeskustan jalankulkuympäristöä parannetaan ja kehitetään jatkuvasti. Tällä hetkellä kävelykeskustan suunnittelun painopiste on Aleksanterinkadun kortteleiden ympäristössä, ja suunnittelun tärkeimpiä päämääriä ovat viihtyisyyden, turvallisuuden, kaupallisen vetovoimaisuuden ja saavutettavuuden parantaminen. Kyselyyn vastanneiden yrittäjien mielestä kävelykeskustaa tulisi laajentaa, sillä laajemman kävelykeskustan nähdään kasvattavan liikevaihtoa ja lisäävän yleisesti ydinkeskustan vetovoimaa. Kävelykatuyrittäjien näkemykset kävelykeskustan suunnittelusta ja kehittämisestä olivat kävelykatujen ulkopuolisia yrittäjiä kielteisempiä. Em. yrittäjien asenteisiin vaikuttavat oletettavasti tutkituilla kävelykaduilla ilmenneet ongelmat. Kyse voi myös olla siitä, että uusien kävelykatujen rakentaminen haittaa kävelykatujen saavutettavuutta. Kadunvarsiliikeyrittäjien yleinen suhtautuminen kävelykeskustan kehittämiseen ja suunnittelupäämääriin on kuitenkin pääosin positiivista. Jatkotutkimuksen kannalta olisi kiinnostavaa selvittää, onko muiden ydinkeskustassa toimivien yritysten, kuten esimerkiksi tavaratalojen ja kauppakeskusten johdon ja kiinteistösijoittajien ja -omistajien suhtautuminen kävelykeskustan kehittämiseen myös positiivista. Tämän lisäksi olisi mielenkiintoista selvittää keskustan käyttäjien ja keskustassa asuvien asenteita kävelykeskustan suunnitteluun, ja verrata tuloksia tässä tutkimuksessa selvitettyihin kadunvarsiliikeyrittäjien näkemyksiin.