Geographical distribution of American cutaneous leishmaniasis and its phlebotomine vectors (Diptera: Psychodidae) in the state of Sao Paulo, Brazil

Background: American cutaneous leishmaniasis (ACL) is a re-emerging disease in the state of Sao Paulo, Brazil. It is important to understand both the vector and disease distribution to help design control strategies. As an initial step in applying geographic information systems (GIS) and remote sensing (RS) tools to map disease-risk, the objectives of the present work were to: (i) produce a single database of species distributions of the sand fly vectors in the state of Sao Paulo, (ii) create combined distributional maps of both the incidence of ACL and its sand fly vectors, and (iii) thereby provide individual municipalities with a source of reference material for work carried out in their area. Results: A database containing 910 individual records of sand fly occurrence in the state of Sao Paulo, from 37 different sources, was compiled. These records date from between 1943 to 2009, and describe the presence of at least one of the six incriminated or suspected sand fly vector species in 183/645 (28.4%) municipalities. For the remaining 462 (71.6%) municipalities, we were unable to locate records of any of the six incriminated or suspected sand fly vector species (Nyssomyia intermedia, N. neivai, N. whitmani, Pintomyia fischeri, P. pessoai and Migonemyia migonei). The distribution of each of the six incriminated or suspected vector species of ACL in the state of Sao Paulo were individually mapped and overlaid on the incidence of ACL for the period 1993 to 1995 and 1998 to 2007. Overall, the maps reveal that the six sand fly vector species analyzed have unique and heterogeneous, although often overlapping, distributions. Several sand fly species - Nyssomyia intermedia and N. neivai - are highly localized, while the other sand fly species - N. whitmani, M. migonei, P. fischeri and P. pessoai - are much more broadly distributed. ACL has been reported in 160/183 (87.4%) of the municipalities with records for at least one of the six incriminated or suspected sand fly vector species, while there are no records of any of these sand fly species in 318/478 (66.5%) municipalities with ACL. Conclusions: The maps produced in this work provide basic data on the distribution of the six incriminated or suspected sand fly vectors of ACL in the state of Sao Paulo, and highlight the complex and geographically heterogeneous pattern of ACL transmission in the region. Further studies are required to clarify the role of each of the six suspected sand fly vector species in different regions of the state of Sao Paulo, especially in the majority of municipalities where ACL is present but sand fly vectors have not yet been identified.

Investigating the distribution of acacia longifolia ssp. sophorae in south-west Victoria using satellite remote sensing and GIS

Mapping and analysis of the distribution of environmental weeds is an important component of strategic weed management. Such information is particularly important in managing 'native invaders', where invasion characteristics must be clearly understood prior to any management action being taken. This paper reports on an investigation of the current distribution of the native invader Acacia longifolia ssp. sophorae (Labill.) Court (coast wattle) in south-west Victoria, using remote sensing and Geographic Information Systems (GIS). Coast wattle was successfully mapped from Landsat ETM imagery using a supervised classification procedure, with 82%, of coast wattle shown on the map accurately depicting coast wattle on the ground. An estimated 11,448 ha were classified as supporting coast wattle, representing 12% of native vegetation in the study area. A more detailed GIS analysis in the Lower Glenelg National Park revealed coast wattle has invaded a limited number of vegetation types, and is more prevalent close to roads and within management zones associated with disturbance. The current regional extent of the species means widespread control is unlikely; hence the immediate focus should be on preventing further spread into areas where it is currently absent. Landsat imagery also proved to be a successful tool for mapping large scale coast wattle distribution, and could be used in long-term monitoring of the species.

Objectively assessing "Walkability" of local communities: using GIS to identify the relevant environmental attributes.

Geographic Information Systems (GIS) may be used to measure objectively, those features of the built environment that may influence walking. Public health research on environmental determinants of physical activity in adults shows that different factors can influence walking for recreation, compared to walking for transport. Most studies have used perceived (self-report) rather than objective measures of potentially relevant environmental attributes. We describe how a previously-developed index of ‘walkability’ was operationalized in an Australian context, using available spatial data.               Attributes believed to be of relevance to walking for transport, that are measurable using GIS, are: Dwelling density (higher-density neighborhoods support greater retail and service variety, resulting in shorter, walkable distances between facilities; driving and parking are more difficult and time consuming). Connectivity (higher intersection densities provide people with a greater variety of potential routes, easier access to major roads where public transport is available and shorter times to get to destinations). Land use mix (the more varied the land use mix and built form, then the more conducive it is to walk to various destinations). Net retail area (there are more options for destinations where goods and services may be purchased and more local employment opportunities that can be reached by walking). The associations of these attributes with walking behaviors can be  examined separately, or in combination. Such GIS data are very helpful in fundamental studies of the environmental determinants of behavior, and also in applied policy research for cities, regions or local communities, to
address public health and environmental issues.

Neighborhood walkability and the walking behavior of Australian adults

Background
The physical attributes of residential neighborhoods, particularly the connectedness of streets and the proximity of destinations, can influence walking behaviors. To provide the evidence for public health advocacy on activity-friendly environments, large-scale studies in different countries are needed. Associations of neighborhood physical environments with adults’ walking for transport and walking for recreation must be better understood.

Method
Walking for transport and walking for recreation were assessed with a validated survey among 2650 adults recruited from neighborhoods in an Australian city between July 2003 and June 2004, with neighborhoods selected to have either high or low walkability, based on objective measures of connectedness and proximity derived from geographic information systems (GIS) databases. The study design was stratified by area-level socioeconomic status, while analyses controlled for participant age, gender, individual-level socioeconomic status, and reasons for neighborhood self-selection.

Results
A strong independent positive association was found between weekly frequency of walking for transport and the objectively derived neighborhood walkability index. Preference for walkable neighborhoods moderated the relationship of walkability with weekly minutes, but not the frequency of walking for transport—walkability was related to higher frequency of transport walking, irrespective of neighborhood self-selection. There were no significant associations between environmental factors and walking for recreation.

Conclusions
Associations of neighborhood walkability attributes with walking for transport were confirmed in Australia. They accounted for a modest but statistically significant proportion of the total variation of the relevant walking behavior. The physical environment attributes that make up the walkability index are potentially important candidate factors for future environmental and policy initiatives designed to increase physical activity.

Neighborhood walkability and TV viewing time among Australian adults

Background
Built-environment attributes of a neighborhood are associated with participation in physical activity and may also influence time spent in sedentary behaviors. Associations of neighborhood walkability (based on dwelling density, street connectivity, land-use mix, and net retail area) and television viewing time were compared in a large, spatially-derived sample of Australian adults.

Methods
Neighborhood-level variables (walkability and socioeconomic status [SES]) were calculated in 154 Australian census collection districts using Geographic Information Systems. Individual-level variables (TV viewing time, time spent in leisure-time physical activity, height, weight, and sociodemographic variables) were collected from adults living in urban areas of Adelaide, Australia using a mail survey (N=2224) in 2003–2004. Multilevel linear regression analysis was conducted in 2006 separately for men and women to examine variations in TV viewing time across tertiles of walkability.

Results
Neighborhood walkability was negatively associated with TV viewing time in women, but not in men. After controlling for neighborhood SES, body mass index, physical activity, and sociodemographic variables, women living in medium- and high-walkable neighborhoods reported significantly less TV viewing time per day (14 minutes and 17 minutes, respectively) compared to those residing in low-walkable neighborhoods.

Conclusions
Built-environment attributes of neighborhoods that are related to physical activity also may play an important role in influencing sedentary behavior, particularly among women. Considering the effects of prolonged sedentary time on health risks, which are independent of physical activity, there is the need for further research to explore how environmental characteristics may contribute to the amount of time spent in sedentary behavior.

The relationship between native vegetation and in-stream salinity: An Australian case study

The Glenelg-Hopkins area is a large regional watershed (2.6 million ha) in southwest Victoria that has been extensively cleared for agriculture. In-stream electrical conductivity (EC) in relation to remnant native vegetation is examined from the headwaters to the upper extent of the estuary of the Glenelg River. Five water quality gauging stations were selected. Their contributing subcatchments represent a continuum of disturbance. Proportions of native vegetation ranged from ∼100% at the headwaters of the river to ∼30% at the furthest downstream gauge station. The relationship between remnant vegetation and in-stream EC was examined using aggregated and non-aggregated land use statistics over a period of 22 years from three land use maps. Increased proportions of native vegetation were significantly negatively correlated with in-stream EC and were consistent across all scenarios investigated.

Destinations that matter: associations with walking for transport

Associations between access to destinations and walking for transport were examined. Households (N=2650) were selected from 32 urban communities varying in walkability and socio-economic status. Respondents reported perceived proximity of destinations, transport-related walking, reasons for neighbourhood selection, and socio-demographic characteristics. Geographic Information Systems data defined objective measures of access to destinations. Measures of access to destinations were associated with transport-related walking. Associations depended on socio-demographic factors and type of destinations. Workplace proximity was the most significant contributor to transport-related walking, especially among women. Regular walking to work resulted in the accrual of sufficient physical activity for health benefits.

Assessment of wilderness quality using the analytic hierarchy process

Wilderness is a unique environmental resource that provides a multitude of use and non-use benefits. The use and management of wilderness depend on the assessment of wilderness quality. Current wilderness assessment in Australia is based on two broad criteria, the remoteness and naturalness of the wilderness, determined using geographic information systems. This paper discusses a complementary assessment method using the Analytic Hierarchy Process (AHP). The AHP can be used to incorporate additional criteria, such as social and cultural criteria, to improve the quality of wilderness assessment. It provides a flexible and compatible method for large-scale wilderness assessments with multiple criteria. The weighting factors for the different criteria can be obtained from expert panels and focus groups.

An assessment tool for sub-catchment to catchment scale indicators of sustainability - a case study in south west Victoria, Australia

The research reported in this paper represents an attempt to produce a practical, indicator-based sustainability assessment tool incorporating all these elements is based on relationships between indicators determined considering spatial influences. Through the use of an existing sustainability indicator set and data currently available, relationships will be determined using Arcview Geographic Information Systems (GIS), correlation analysis and Principal Component Analysis (PCA). Indicator interactions will be identified at two spatial scales and compared to determine impacts of changing spatial scale. Further PCA and multiple regression analyses will then be used to reduce the complexity of the indicator set. These findings will be incorporated into a practical indicator-based assessment tool through the adoption of the Analytic Hierarchy Process (AHP) combined with GIS techniques that will then be validated. Once validated the tool can be used to aid in guiding planning and decision-making regarding sustainable development in the Glenelg Hopkins catchment, Victoria; while also moving towards producing a standard set of procedures for assessing sustainability.

An Australian version of the neighborhood environment walkability scale : validity evidence

This study examined validity evidence for the Australian version of the Neighborhood Environment Walkability Scale (NEWS-AU). A stratified two-stage cluster sampling design was used to recruit 2,650 adults from Adelaide (Australia). The sample was drawn from residential addresses within eight high-walkable and eight low-walkable suburbs matched for socio-economic status (SES). Neighborhood walkability was measured using Geographic Information Systems data on dwelling density, intersection density, net retail area, and land-use mix. Participants completed the NEWS-AU and reported weekly minutes of walking for transport and recreation (International Physical Activity Questionnaire [IPAQ]). Multilevel confirmatory factor analysis (MCFA) was used to define the individual- and Census Collection District (CCD)-level measurement model of the NEWS-AU. Seven individual-level and five CCD-level factors were identified. These measurement models were somewhat similar to those of the original Neighborhood Environment Walkability Scale (NEWS). Patterns of associations between the NEWS-AU factors/scales and the walking measures provided some validity evidence for the instrument.

Relationships of land use mix with walking for transport : do land uses and geographical scale matter?

Physical activity and public health recommendations now emphasize the creation of activity-friendly neighborhoods. Mixed land use in a neighborhood is important in this regard, as it reflects the availability of destinations to which residents can walk or ride bicycles, and thus is likely to contribute to residents’ active lifestyles that in turn will influence their overall health. Relationships between land use mix (LUM) and physical activity have not been apparent in some studies, which may be because geographical scale and the specificity of hypothesized environment–behavior associations are not taken into account. We compared the strength of association of four Geographic Information Systems-derived LUM measures with walking for transport and perceived proximity to destinations. We assessed physical activity behaviors of 2,506 adults in 154 Census Collection Districts (CCDs) in Adelaide, Australia, for which ‘‘original’’ LUM measures were calculated, and then refined by either: accounting for the geographic scale of measurement; including only the most-relevant land uses; or, both. The refined (but not the ‘‘original’’) LUM measures had significant associations with the frequency of walking for transport (p < 0.05) and area-corrected measures had significant associations with the duration of walking for transport. All LUM measures had significant associations with perceived proximity to destinations, but stronger associations were seen when using the refined measures compared with the original LUM. Identifying the LUM attributes most strongly associated with walking for transport is a priority and can inform environmental and policy initiatives that are needed to promote health-enhancing physical activity.

The longitudinal influence of home and neighbourhood environments on children's body mass index and physical activity over 5 years : the CLAN study

Objective: To determine the independent contributions of family and neighbourhood environments to changes in youth physical activity and body mass index (BMI) z-score over 5 years.

Methods: In 2001, 2004 and 2006, 301 children (10–12 years at baseline) had their height and weight measured (BMI was converted to z-scores using Centers for Disease Control and Prevention reference charts; see http://www.cdc.gov/growthcharts) and moderate-to-vigorous physical activity (MVPA) assessed using accelerometers. In 2001, parents reported on the home environment (social support, role modelling, rules and restrictions, physical environment) and perceived neighbourhood environment (local traffic, road safety, sporting venues, public transport), and Geographic Information Systems were used to map features of the neighbourhood environment (destinations, road connectivity, traffic exposure). Generalized estimating equations were used to predict average BMI z-score and MVPA over time from baseline home and perceived and objective neighbourhood environment factors.

Results: Among boys, maternal education and heavy traffic were inversely associated, and sibling physical activity, maternal role modelling of MVPA and the presence of dead-end roads were positively associated with MVPA. Having unmarried parents, maternal MVPA role modelling and number of home sedentary items were positively associated with BMI z-score among boys. Among girls, having siblings, paternal MVPA role modelling, physical activity rules and parental physical activity co-participation were positively associated with MVPA. Having unmarried parents and maternal sedentary behaviour role modelling were positively associated, and number of sedentary behaviour rules and physical activity items were inversely associated with BMI z-score among girls.

Conclusion: The home environment seems more important than the neighbourhood environment in influencing children's physical activity and BMI z-score over 5 years. Physical activity and weight gain programmes among youth should focus on parental role modelling, rules around sedentary and active pursuits, and parental support for physical activity. Intervention studies to investigate these strategies are warranted.

An optimal transportation routing approach using GIS-based dynamic traffic flows

This paper examines the value of real-time traffic information gathered through Geographic Information Systems for achieving an optimal vehicle routing within a dynamically stochastic transportation network. We present a systematic approach in determining the dynamically varying parameters and implementation attributes that were used for the development of a Web-based transportation routing application integrated with real-time GIS services. We propose and implement an optimal routing algorithm by modifying Dijkstra’s algorithm in order to incorporate stochastically changing traffic flows. We describe the significant features of our Web application in making use of the real-time dynamic traffic flow information from GIS services towards achieving total costs savings and vehicle usage reduction. These features help users and vehicle drivers in improving their service levels and productivity as the Web application enables them to interactively find the optimal path and in identifying destinations effectively.

Deduction of high level spatial relations

The problem of deriving spatial relationships between objects in general requires high level abstract representation, and it would pose difficulties even for human observer. Based on a formalism for spatial layouts proposed earlier [KiV92, VeK921, we present methods for deducing high level spatial relations between objects by an active, sighted agent in a large-scale environment. The deduction of spatial relations is based on simple visual clues, and thus this technique is more feasible than schemes that rely on complex object recognition.