Discontinuous local semiflows for Kurzweil equations leading to LaSalle`s invariance principle for differential systems with impulses at variable times

In this paper, we consider an initial value problem for a class of generalized ODEs, also known as Kurzweil equations, and we prove the existence of a local semidynamical system there. Under certain perturbation conditions, we also show that this class of generalized ODEs admits a discontinuous semiflow which we shall refer to as an impulsive semidynamical system. As a consequence, we obtain LaSalle`s invariance principle for such a class of generalized ODEs. Due to the importance of LaSalle`s invariance principle in studying stability of differential systems, we include an application to autonomous ordinary differential systems with impulse action at variable times. (C) 2011 Elsevier Inc. All rights reserved.

Identification of genes associated with local aggressiveness and metastatic behavior in soft tissue tumors

Soft tissue tumors represent a group of neoplasia with different histologic and biological presentations varying from benign, locally confined to very aggressive and metastatic tumors. The molecular mechanisms responsible for such differences are still unknown. The understanding of these molecular alterations mechanism will be critical to discriminate patients who need systemic treatment from those that can be treated only locally and could also guide the development of new drugs` against this tumors. Using 102 tumor samples representing a large spectrum of these tumors, we performed expression profiling and defined differentially expression genes that are likely to be involved in tumors that are locally aggressive and in tumors with metastatic potential. We described a set of 12 genes (SNRPD3, MEGF9, SPTAN-1, AFAP1L2, ENDOD1, SERPIN5, ZWINTAS, TOP2A, UBE2C, ABCF1, MCM2, and ARL6IP5) showing opposite expression when these two conditions were compared. These genes are mainly related to cell-cell and cell-extracellular matrix interactions and cell proliferation and might represent helpful tools for a more precise classification and diagnosis as well as potential drug targets.

Local solvability for a class of evolution equations

Motivated by the celebrated example of Y. Kannai of a linear partial differential operator which is hypoelliptic but not locally solvable, we consider it class of evolution operators with real-analytic coefficients and study their local solvability both in L(2) and in the weak sense. In order to do so we are led to propose a generalization of the Nirenberg-Treves condition (psi) which is suitable to our study. (C) 2009 Published by Elsevier Inc.

Derived tame local and two-point algebras

We determine derived representation type of complete finitely generated local and two-point algebras over an algebraically closed field. (C) 2009 Elsevier Inc. All rights reserved.

Leisure experiences in tourist attractions : exploring the motivations of local residents

This study was conducted to explore leisure motivations with regard to tourist attractions. A survey of a convenience sample of residents of Melbourne, Australia, was conducted. The sample was then segmented based on the likelihood of visiting a cross-section of Melbourne's tourist attractions in the next 6 months. Analysis using Unger and Kernan's (1983) Subjective Leisure Scale (SLS) was then undertaken to explore whether there were differences across the segments in terms of their leisure motivations. The results highlight that, within this context, intrinsic satisfaction, perceived freedom and arousal emerged as stronger underlying dimensions of motivations to visit tourist attractions, rather than mastery, spontaneity and involvement. This information provides insights for marketers of tourist attractions with regard to what residents are seeking when they visit local tourist attractions. The information can be used to develop more positive experiences at tourist attractions for this important sector of the market.

Bypassing luminal barriers, delivery to a gut addressin by parenteral targeting elicits local IgA responses

Induction of mucosal immunity, particularly to subunit vaccines, has been problematic. The primary hurdle to successful mucosal vaccination is the effective delivery of vaccine antigen to the mucosal associated lymphoid tissue. Physical and chemical barriers restrict antigen access and, moreover, immune responses induced in the mucosa can be biased towards tolerance or non-reactivity. We proposed that these difficulties could be circumvented by targeting antigen to the gastrointestinal associated lymphoid tissue via systemic (parenteral) rather than alimentary routes, using antibodies specific for the mucosal addressin cellular adhesion molecule-1 (MAdCAM). After intravenous or intramuscular injection of such rat antibodies in mice, we found a greatly enhanced (up to 3 logs) anti-rat antibody response. MAdCAM targeting induces a rapid IgA antibody response in the gut and vastly improves the systemic antibody response. Targeting also enhanced T cell proliferation and cytokine responses. Parenteral targeting of mucosal addressins may represent a generic technique for bypassing mucosal barriers and eliminating the need for adjuvants in the induction of proximal and systemic immunity.

Development of a reliable measure of walking within and outside the local neighbourhood: RESIDE's neighborhood physical activity questionnarire.

Background: The RESIDential Environment project (RESIDE) is a longitudinal study evaluating the impact of a new residential design code on walking. Objective: To develop a reliable measure of walking – undertaken within and outside the neighborhood – and overall physical activity. Methods: A test–retest reliability study was undertaken (n = 82, mean age 39 years). The instrument was based on the International Physical Activity Questionnaire (IPAQ-short version) and Active Australia Survey. It measured usual frequency and duration of (1) recreational- and transport-related walking within and outside the neighborhood and (2) other vigorous and moderate physical activities. Results: Reliability of recall of whether participants had walked within (k = 0.84) and outside (0.73) the neighborhood was acceptable. Similarly, recall of frequency and duration of transport and recreational-related walking within the neighborhood was excellent (ICC ≥ 0.82), as was recall of transport-related walking trips outside the neighborhood (ICC ≥ 0.84). Reliability for duration of recreational walking outside the neighborhood was fair to good (ICC = 0.55). The reliability of indices of total physical activity based on MET min/week (ICC = 0.82) and MET min/week dichotomized to ‘sufficient’ physical activity for health (kappa = 0.67) were both acceptable. Conclusions:  The Neighborhood Physical Activity Questionnaire (NPAQ) is sufficiently reliable for studies examining environmental correlates of walking within the neighborhood.

Are perceptions of the local environment related to neighbourhood satisfaction and mental health in adults?

Background: Perceptions of environmental attributes can influence satisfaction with where people live and mental health status. We examined the association between perceived environmental characteristics, neighbourhood satisfaction, and self-rated mental health.

Methods: We report cross-sectional data from the Physical Activity in Localities and Community Environments (PLACE) study in Australia (n = 2194). Self-report data included socio-demographics, perceived attributes of the environment, neighbourhood satisfaction (NS) and mental health status. Neighbourhood SES was obtained through census data. Factor analysis was used to identify dimensions of NS. Generalized linear models were used to examine associations between NS and perceived environment characteristics and whether aspects of NS were independently associated with mental health.

Results: NS factors identified were safety and walkability, access to destinations, social network, travel network, and traffic and noise. Perceived environmental characteristics of aesthetics and greenery, land use mix – diversity, street connectivity, traffic safety, infrastructure for walking, access to services and barriers to walking were found to be positively associated with these factors. Traffic load and crime were negatively associated. Three NS factors (safety and walkability, social network, and traffic and noise) were independent predictors of mental health.

Conclusions: Neighbourhood satisfaction may mediate the association between perceived environmental characteristics and measures of mental health in adults.

Children's active free play in local neighborhoods : a behavioral mapping study

Many Australian children are more sedentary than they should be, and almost one in five are currently overweight or obese. Some children may face difficulties finding opportunities to be active, having poor access to safe public open spaces or having low independent mobility limiting their access to places to play. This study aimed to examine children's access to places in their neighborhood for active free play and how these vary by age, sex and socioeconomic status (SES). Behavioral maps of the local neighborhood were completed by children (8-12 years) from five primary schools across different areas of Melbourne. Children living in low SES outer-urban neighborhoods had to travel greater distances to access local parks compared with those in inner-urban mid and high SES areas. One-third (32%) of children reported an independent mobility range of <100 m from home. In conclusion, for some children opportunities to engage in active free play in the local neighborhood may be limited due to lack of parks in close proximity to home and restricted independent mobility. It is important to collaborate with local governments, urban planners and community groups to improve access to neighborhood parks and to promote a sense of neighborhood safety.

Evaluation of the implementation of a state government community design policy aimed at increasing local walking : design issues and baseline results from RESIDE, Perth Western Australia

Objectives.
To describe the design and baseline results of an evaluation of the Western Australian government's pedestrian-friendly subdivision design code (Liveable Neighborhood (LN) Guidelines).
Methods.

Baseline results (2003–2005) from a longitudinal study of people (n = 1813) moving into new housing developments: 18 Liveable, 11 Hybrid and 45 Conventional (i.e., LDs, HDs and CDs respectively) are presented including usual recreational and transport-related walking undertaken within and outside the neighborhood, and 7-day pedometer steps.
Results.

At baseline, more participants walked for recreation and transport within the neighborhood (52.6%; 36.1% respectively), than outside the neighborhood (17.7%; 13.2% respectively). Notably, only 20% of average total duration of walking (128.4 min/week (SD159.8)) was transport related and within the neighborhood. There were few differences between the groups' demographic, psychosocial and perceived neighborhood environmental characteristics, pedometer steps, or the type, amount and location of self-reported walking (p > 0.05). However, asked what factors influenced their choice of housing development, more participants moving into LDs reported aspects of their new neighborhood's walkability as important (p < 0.05).
Conclusions.

The baseline results underscore the desirability of incorporating behavior and context-specific measures and value of longitudinal designs to enable changes in behavior, attitudes, and urban form to be monitored, while adjusting for baseline residential location preferences.