Changing Patterns of Residential Centrality : Population and Household Shift in Large Canadian CMAs, 1971-1996.

Cet article se penche sur l'évolution, entre 1971 et 1996, des régions métropolitaines canadiennes dont la population atteint ou excède 500 000 personnes. Il se sert de gradients mesurant la densité résidentielle ainsi que des changements de population dans différentes zones d'urbanisation afin d'illustrer les tendances ayant trait à la centralité résidentielle au cours des vingt-cinq dernières années. Cette recherche indique que toutes les régions métropolitaines analysées ont connu, avec divers degrés d'intensité, une tendance à la décentralisation. Lorsque les changements de population dans le centre-ville et les quartiers centraux sont considérés de pair avec un nivellement des gradients de densité, seule Vancouver montre des signes incontestables de recentralisation. Trois autres régions, Toronto, Victoria et Calgary, jouissent aussi d'une hausse de population dans leurs quartiers centraux. Bien que souffrant d'une forte baisse de population, la densité de ces secteurs demeure élevée à Montréal et Québec. Leur centralité est cependant résiduelle, legs des fortes densités du passé. La prise en compte des ménages plutôt que des résidents montre que toutes les régions métropolitaines examinées dans cette recherche ont fait l'objet de nouvelles constructions dans leurs secteurs centraux. Selon les données employées, nous observons une décentralisation ou une certaine centralisation des régions métropolitaines. La principale conclusion de cet article est que la recentralisation des régions métropolitaines est fortement associée à leur prospérité et à leur taux de croissance.The research focuses on Canadian CMAs with populations of 500 000 or greater over the period 1971-1996. It uses population density gradients and enumeration of population and household shift to assess changing patterns of residential centrality over the twenty-five year period. Results indicate that all of the CMAs examined have experienced continued outward dispersion, some more so than others. When population change in core and inner-city zones is examined in conjunction with reduced density gradients, only one Canadian metropolitan area, Vancouver, shows indisputable signs of strong recentralization. Three other CMAs, Toronto, Victoria and Calgary, also experience some re-population of their central parts, while Montréal and Québec City are shown to maintain what we call "residual" centrality. However, when recentralization is gauged using household enumeration instead of population counts, all of the places studied show evidence of new housing production in the central city. The answer to the central question regarding residential centrality is thus a mixed one, yes and no. Overall, we conclude that there is a direct link between evolutionary patterns within the national urban System and changes observed in residential centrality. Whatever the measure used, highest rates of recentralization accompany strong metropolitan-wide growth over the 25-year period

Using geographic profiling to locate elusive nocturnal animals: A case study with spectral tarsiers

© 2015 The Zoological Society of London. Estimates of biodiversity, population size, population density and habitat use have important implications for management of both species and habitats, yet are based on census data that can be extremely difficult to collect. Traditional assessment techniques are often limited by time and money and by the difficulties of working in certain habitats, and species become more difficult to find as population size decreases. Particular difficulties arise when studying elusive species with cryptic behaviours. Here, we show how geographic profiling (GP) - a statistical tool originally developed in criminology to prioritize large lists of suspects in cases of serial crime - can be used to address these problems. We ask whether GP can be used to locate sleeping sites of spectral tarsiers Tarsius tarsier in Sulawesi, Southeast Asia, using as input the positions at which tarsier vocalizations were recorded in the field. This novel application of GP is potentially of value as tarsiers are cryptic and nocturnal and can easily be overlooked in habitat assessments (e.g. in dense rainforest). Our results show that GP provides a useful tool for locating sleeping sites of this species, and indeed analysis of a preliminary dataset during field work strongly suggested the presence of a sleeping tree at a previously unknown location; two sleeping trees were subsequently found within 5m of the predicted site. We believe that GP can be successfully applied to locating the nests, dens or roosts of elusive animals such as tarsiers, potentially improving estimates of population size with important implications for management of both species and habitats.We thank Operation Wallacea for supporting S.C.F. in thisproject and for providing logistical support for the fieldwork,and Aidan Kelsey for invaluable assistance in the field. Wethank the Indonesian Institute of Sciences (LIPI) andKementerian Riset dan Teknologi Republik Indonesia(RISTEK) for providing permission to undertake the work(RISTEK permit no. 211/SIP/FRP/SM/VI/2013, and BalaiKonservasi Sumber Daya Alam (BKSDA) for theirassistance

Evaluation of stress induced damage in composite material

The aim of this work was to investigate the growth of damage within a composite material. The work involved the use of acoustic emission to monitor the growth and evolution of damage within a composite material, A second part of the work considered the reduction in composite material elastic modulus to reflect the evolution of this damage in these composite materials. The many failure mechanisms in the composite material produced different acoustic emission waveforms. The waveform parameters amplitude, ringdown count and risetime, were used to cluster the acoustic emission events into groups that characterised the evolution of damage in unidirectional glass fibre polyester composite material. The occurrence of high energy Cluster 1 events was confined to experimental periods where fibre debonding or failures were expected. Throughout the experiment small amplitude acoustic emission events were related to the deformation of the matrix. A mesoscopic continuum damage model was developed to model the development of matrix cracking and fibre debonding damage in a composite material. The two increasing damage parameters (d, d') reflected the accumulation of damage by the reduction in the transverse and shear moduli. The fibre debonding from the matrix was controlled by the transverse stresses relative to the fibre pulling the fibre away from the matrix. The matrix crack was modelled as a combination of shear and transverse stresses. Finite element analysis was combined with the model to provide examples of the damage growth pattern for a range of composite material with changing fibre angles. The results from three angle orientations showed that damage was initiated at a lower stress for weaker material with larger fibre angles. The growth patterns for the different angles were not similar, reflecting the differing development of shear and transverse induced damage. The influence of the element dimension in the mesh was tested with two different sizes and found to produce similar results

The exchange of actin-bound ADP in muscular activity

Szent-Gyorgyi and Prior (1966) provided evidence for the exchange of actin-bound ADP during superprecipitation of actomyosin and myofibrils. Tentative experimental support was given by Cheesman and Whitehead (1968) to the suggestion that the exchange also occurred in vivo as a result of muscular contraction. Further experiments with improved techniques have confirmed these findings. Injections of C-glucose subcutaneously into frogs leads to a rapid incorporation of label into the total ATP by synthesis de novo. The total ATP therefore assumes a high specific activity and, by an exchange of nucleotide, the bound ADP associated with actin also becomes labelled. In phasic muscles of active frogs the specific activity of the bound ADP soon exceeds that of the total ATP, which suggests that the myofibrils are in contact with a highly labelled nucleotide pool. The labelling of bound ADP in tonic muscles is much slower.Curarisation, and therefore muscular paralysis, before the injection of C-glucose produces an inhibition of uptake of radio active isotope, which provides the first support for the view that the exchange of nucleotide is attendant upon contraction.Stimulation, either by depolarisation with KC1 or by direct electrical excitation, brings the bound nucleotide into exchange with the pool. Since an exchange of nucleotide seems only to occur in vitro as a result of depolymerisation or a change in the conformation of actin, these results provide strong evidence for a similar change in the physical state of this protein during muscular activity.<p

The conservation value of human-modified landscapes for the world's primates

Land-use change pushes biodiversity into human-modified landscapes, where native ecosystems are surrounded by anthropic land covers (ALCs). Yet, the ability of species to use these emerging covers remains poorly understood. We quantified the use of ALCs by primates worldwide, and analyzed species' attributes that predict such use. Most species use secondary forests and tree plantations, while only few use human settlements. ALCs are used for foraging by at least 86 species with an important conservation outcome: those that tolerate heavily modified ALCs are 26% more likely to have stable or increasing populations than the global average for all primates. There is no phylogenetic signal in ALCs use. Compared to all primates on Earth, species using ALCs are less often threatened with extinction, but more often diurnal, medium or large-bodied, not strictly arboreal, and habitat generalists. These findings provide valuable quantitative information for improving management practices for primate conservation worldwide

Mannitol challenge testing for asthma in a community cohort of young adults

BACKGROUND AND OBJECTIVE: Mannitol challenge testing is an established tool for clinical asthma diagnosis, and can be performed outside of specialized respiratory laboratories. Despite applicability in both clinical and non-clinical populations, with different pre-test asthma probabilities, differences in diagnostic properties have not been well explored. This study aimed to quantify the diagnostic utility of mannitol challenge testing for asthma in a community cohort and a symptomatic wheezing subset of this cohort. METHODS: During the 22-year follow-up of the Western Australian Pregnancy (Raine) Cohort, 772 participants (384 males) completed mannitol challenge and skin prick testing and respiratory health questionnaires, of whom 148 reporting wheeze in the past 12 months were included in a wheezing subset. RESULTS: Responsiveness to mannitol had low sensitivity (19%) and high specificity (97%) to identify current asthma in the complete cohort, with positive and negative predictive values (PPV and NPV) of 45% and 92%, respectively. Within the wheezing subset, sensitivity (19%) and specificity (94%) remained similar, but PPV increased to 79%, and NPV decreased to 52%. CONCLUSION: Our findings support previously reported high specificity and good PPV for mannitol challenge testing in symptomatic wheezing populations, and highlight the need for caution when interpreting mannitol test results in non-clinical populations

Canonical Wnt/Β-catenin signaling is required for maintenance but not activation of Pitx2 expression in neural crest during eye development

Pitx2 is a paired-like homeodomain gene that acts as a key regulator of eye development. Despite its significance, upstream regulation of Pitx2 expression during eye development remains incompletely understood. We use neural crest-specific ablation of Ctnnb1 to demonstrate that canonical Wnt signaling is not required for initial activation of Pitx2 in neural crest. However, canonical Wnt signaling is subsequently required to maintain Pitx2 expression in the neural crest. Eye development in Ctnnb1 -null mice appears grossly normal early but significant phenotypes emerge following loss of Pitx2 expression. LEF-1 and Β-catenin bind Pitx2 promoter sequences in ocular neural crest, indicating a likely direct effect of canonical Wnt signaling on Pitx2 expression. Combining our data with previous reports, we propose a model wherein a sequential code of retinoic acid followed by canonical Wnt signaling are required for activation and maintenance of Pitx2 expression, respectively. Other key transcription factors in the neural crest, including Foxc1 , do not require intact canonical Wnt signaling. Developmental Dynamics 239:3215–3225, 2010. © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78327/1/22459_ftp.pd

Raiders of the Lost Bark: Orangutan Foraging Strategies in a Degraded Landscape

Deforestation is rapidly transforming primary forests across the tropics into human-dominated landscapes. Consequently, conservationists need to understand how different taxa respond and adapt to these changes in order to develop appropriate management strategies. Our two year study seeks to determine how wild Sumatran orangutans (Pongo abelii) adapt to living in an isolated agroforest landscape by investigating the sex of crop-raiders related to population demographics, and their temporal variations in feeding behaviour and dietary composition. From focal animal sampling we found that nine identified females raided cultivated fruits more than the four males. Seasonal adaptations were shown through orangutan feeding habits that shifted from being predominantly fruit-based (56% of the total feeding time, then 22% on bark) to the fallback food of bark (44%, then 35% on fruits), when key cultivated resources such as jackfruit (Artocarpus integer), were unavailable. Cultivated fruits were mostly consumed in the afternoon and evening, when farmers had returned home. The finding that females take greater crop-raiding risks than males differs from previous human-primate conflict studies, probably because of the low risks associated (as farmers rarely retaliated) and low intraspecific competition between males. Thus, the behavioral ecology of orangutans living in this human-dominated landscape differs markedly from that in primary forest, where orangutans have a strictly wild food diet, even where primary rainforests directly borders farmland. The importance of wild food availability was clearly illustrated in this study with 21% of the total orangutan feeding time being allocated to feeding on cultivated fruits. As forests are increasingly converted to cultivation, humans and orangutans are predicted to come into conflict more frequently. This study reveals orangutan adaptations for coexisting with humans, e.g. changes in temporal foraging patterns, which should be used for guiding the development of specific human-wildlife conflict mitigation strategies to lessen future crop-raiding and conflicts

Analysis of RNA splicing defects in PITX2 mutants supports a gene dosage model of Axenfeld-Rieger syndrome

BACKGROUND: Axenfeld-Rieger syndrome (ARS) is associated with mutations in the PITX2 gene that encodes a homeobox transcription factor. Several intronic PITX2 mutations have been reported in Axenfeld-Rieger patients but their effects on gene expression have not been tested. METHODS: We present two new families with recurrent PITX2 intronic mutations and use PITX2c minigenes and transfected cells to address the hypothesis that intronic mutations effect RNA splicing. Three PITX2 mutations have been analyzed: a G>T mutation within the AG 3' splice site (ss) junction associated with exon 4 (IVS4-1G>T), a G>C mutation at position +5 of the 5' (ss) of exon 4 (IVS4+5G>C), and a previously reported A>G substitution at position -11 of 3'ss of exon 5 (IVS5-11A>G). RESULTS: Mutation IVS4+5G>C showed 71% retention of the intron between exons 4 and 5, and poorly expressed protein. Wild-type protein levels were proportionally expressed from correctly spliced mRNA. The G>T mutation within the exon 4 AG 3'ss junction shifted splicing exclusively to a new AG and resulted in a severely truncated, poorly expressed protein. Finally, the A>G substitution at position -11 of the 3'ss of exon 5 shifted splicing exclusively to a newly created upstream AG and resulted in generation of a protein with a truncated homeodomain. CONCLUSION: This is the first direct evidence to support aberrant RNA splicing as the mechanism underlying the disorder in some patients and suggests that the magnitude of the splicing defect may contribute to the variability of ARS phenotypes, in support of a gene dosage model of Axenfeld-Rieger syndrome

Medidas da dinâmica respiratória em idosos participantes de grupos de terceira idade

OBJETIVO: analisar medidas da dinâmica respiratória em participantes de grupos de terceira idade. MÉTODO: participaram 41 pessoas, 32 do sexo feminino e nove do masculino, idade média de 69,90 anos. A avaliação foi realizada por meio das medidas de tempos máximos de fonação (TMF) das vogais /a/, /i/, /u/, das consoantes /s/ e /z/ e contagem de números; relação s/z; medida de capacidade vital (CV) e cocientes fônicos simples (CFS) e composto (CFC). RESULTADOS: os valores médios dos indivíduos do sexo masculino para os TMF das vogais, consoantes e contagem de números foram respectivamente, 18,11s; 19,22s; 19,11s; 15,22s e 15,61s e 18,77s, sendo 0,98 o valor da relação s/z. No sexo feminino, as médias das mesmas medidas de TMF foram respectivamente 13,94s; 14,19s; 13,98s; 10,11s e 11,63s; 13,90s, sendo 0,92 a relação s/z. A média de TMF das vogais foi significativamente maior que a média das consoantes no grupo feminino. O valor médio da CV sem oclusão nasal no sexo feminino foi de 2.247ml e no masculino de 3.211 ml. Foi verificada relação significante entre a medida de CV e a variável idade, no grupo feminino. Os valores médios do CFS nos grupos de homens e mulheres foram respectivamente 182,11 ml/s e 176,58 ml/s e do CFC, 184,35 ml/s e 186,93 ml/s. CONCLUSÃO: as medidas da dinâmica respiratória dos participantes estiveram próximas aos valores de referência para adultos na literatura, bem como próximos aos de estudos de idosos, havendo diferenças para mais ou para menos nas diferentes medidas estudadas.PURPOSE: to analyze the measures of respiratory dynamics in elderly citizens taking part in elderly groups. METHOD: we studied 41 participants, 32 female and nine male, mean age of 69.90 years. The evaluation included measures of the maximum phonation time (MPT) of vowels /a/, /i/, /u/, consonants /s/ and /z/, and counting numbers; s/z ratio; value of Vital Capacity (VC), Simple Phonic Quotient (SPQ) and Composed Phonic Quotient (CPQ). RESULTS: the mean values of MPT, for males, of vowels, consonants and counting numbers were respectively 18.11s; 19.22s; 19.11s; 15.22s and 15.61s and 18.77s, and the s/z ratio was 0.98. For females, the means for the same measures of TMF were respectively 13.94s; 14.19s; 13.98s; 10.11s and 11.63s; 13.90 s and 0.92 to the s/z ratio. The mean time of vowels emission was significantly higher than the mean value for the consonants in the female group. The mean value of VC without nasal occlusion was 2.247ml for females and 3.211ml for males. Significant relation between the VC and age was observed in the female group. The mean values of SPQ found for the male and female groups were, respectively, 182.11 ml/s e 176.58 ml/s. The mean values of CPQ were 184.35 ml/s for the males and 186.93 ml/s for the females. CONCLUSION: measures of respiratory dynamics concerning the participants were close to the reference values in literature for adults as well as close to those of older studies, and differences were a little more or less than the different studied measures.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UNESP Faculdade de Filosofia e Ciências Departamento de FonoaudiologiaUNESP Faculdade de Filosofia e Ciências Departamento de Fonoaudiologi