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1.
J Chem Phys ; 157(10): 104301, 2022 Sep 14.
Article in English | MEDLINE | ID: mdl-36109229

ABSTRACT

SiC2 is a fascinating molecule due to its unusual bonding and astrophysical importance. In this work, we report the first global potential energy surface (PES) for ground-state SiC2 using the combined-hyperbolic-inverse-power-representation method and accurate ab initio energies. The calibration grid data are obtained via a general dual-level protocol developed afresh herein that entails both coupled-cluster and multi-reference configuration interaction energies jointly extrapolated to the complete basis set limit. Such an approach is specially devised to recover much of the spectroscopy from the PES, while still permitting a proper fragmentation of the system to allow for reaction dynamics studies. Besides describing accurately the valence strongly bound region that includes both the cyclic global minimum and isomerization barriers, the final analytic PES form is shown to properly reproduce dissociation energies, diatomic potentials, and long-range interactions at all asymptotic channels, in addition to naturally reflect the correct permutational symmetry of the potential. Bound vibrational state calculations have been carried out, unveiling an excellent match of the available experimental data on c-SiC2(A11). To further exploit the global nature of the PES, exploratory quasi-classical trajectory calculations for the endothermic C2 + Si → SiC + C reaction are also performed, yielding thermalized rate coefficients for temperatures up to 5000 K. The results hint for the prominence of this reaction in the innermost layers of the circumstellar envelopes around carbon-rich stars, hence conceivably playing therein a key contribution to the gas-phase formation of SiC, and eventually, solid SiC dust.

2.
Phys Chem Chem Phys ; 23(46): 26227-26240, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34787132

ABSTRACT

While it is now well established that large carbon chain species and radiative electron attachment (REA) are key ingredients triggering interstellar anion chemistry, the role played by smaller molecular anions, for which REA appears to be an unlikely formation pathway, is as yet elusive. Advancing this research undoubtedly requires the knowledge (and modeling) of their astronomical abundances which, for the case of C2N-, is largely hindered by a lack of accurate spectroscopic signatures. In this work, we provide such data for both ground -CCN-(3Σ-) and low-lying c-CNC-(1A1) isomers and their singly-substituted isotopologues by means of state-of-the-art rovibrational quantum chemical techniques. Their quartic force fields are herein calibrated using a high-level composite energy scheme that accounts for extrapolations to both one-particle and (approximate) -particle basis set limits, in addition to relativistic effects, with the final forms being subsequently subject to nuclear motion calculations. Besides standard spectroscopic attributes, the full set of computed properties includes fine and hyperfine interaction constants and can be readily introduced as guesses in conventional experimental data reduction analyses through effective Hamiltonians. On the basis of benchmark calculations performed anew for a minimal test set of prototypical triatomics and limited (low-resolution) experimental data for -CCN-(3Σ-), the target accuracies are determined to be better than 0.1% of experiment for rotational constants and 0.3% for vibrational fundamentals. Apart from laboratory investigations, the results here presented are expected to also prompt future astronomical surveys on C2N-. To this end and using the theoretically-predicted spectroscopic constants, the rotational spectra of both -CCN-(3Σ-) and c-CNC-(1A1) are derived and their likely detectability in the interstellar medium is further explored in connection with working frequency ranges of powerful astronomical facilities. Our best theoretical estimate places c-CNC-(1A1) at about 15.3 kcal mol-1 above the ground-state -CCN-(3Σ-) species.

3.
Braz. j. biol ; 79(4): 617-624, Nov. 2019. graf
Article in English | LILACS | ID: biblio-1001483

ABSTRACT

Abstract Aquatic macrophytes have a recognized role in ecosystem structuring and an important position in trophic cascades interactions, whose understanding is to improve water quality. In recent years, the number of studies on the role of aquatic macrophytes in trophic webs and interactions has increased, but South America has made little progress in research in the area. In this study, we investigated the main gaps and perspectives for future studies on macrophytes and trophic interactions, analyzing global publications, especially those conducted by South American researchers. We accessed publications using an international database (Thomson Reuters ISI-Web of Knowledge-(formerly Institute for Scientific Information)) from 1980 to 2015. We ranked each article by ecosystem and study approach, biological organization and interacting taxonomic groups (phytoplankton, periphyton, zooplankton, aquatic invertebrates, fish and birds), countries publishing in cooperation and affiliations. The results showed that published studies (n = 242) emphasizing aquatic plants in trophic interactions increased in 35 years. Comparing the contributions of the 32 countries investigated, those from South America as first affiliation, had few publications (n = 26) and in cooperation (n = 7). The largest volume of articles indexed by the researchers dealt with the dynamics and structure of aquatic assemblages, webs and trophic interactions. Ecosystems such reservoirs and wetlands have received little attention. Large numbers of studies have encompassed community-wide aquatic approaches, including in South American studies, the interactions between macrophytes, zooplankton and phytoplankton were the second most studied interactions of all indexed articles. Knowledge about trophic cascade and interactions has been successfully enhanced in several countries with the purpose of restructuring communities and restore water quality of many ecosystems. In summary, we conclude that studies in the area of trophic interactions mediated by macrophytes may be directed in a way to attenuate international asymmetries, encouraging the increase of scientific productivity in South America.


Resumo Macrófitas aquáticas tem reconhecida função na estruturação de ecossistemas e importante papel nas interações tróficas em cascata, cujo entendimento é chave para melhorar a qualidade da água. Nos últimos anos, o número de estudos sobre o papel das macrófitas aquáticas nas interações e teia trófica aumentaram mas, a América do Sul progrediu pouco em pesquisas na área. Nesse estudo investigamos as principais lacunas e perspectivas para estudos futuros sobre macrófitas e interações tróficas analisando publicações mundiais, especialmente aquelas conduzidas por pesquisadores sul-americanos. Acessamos publicações usando base de dados internacional (Thomson Reuters ISI Web of Knowledge) entre 1980 a 2015. Computamos para cada artigo a organização biológica e grupos taxonômicos em interação (fitoplâncton, perifíton, zooplâncton, invertebrados aquáticos, peixes e aves), ecossistema estudado e abordagem de pesquisa, a cooperação entre países da América do Sul e demais, além das filiações. Os resultados mostraram que estudos publicados (n = 242) enfatizando plantas aquáticas em interações tróficas cresceram em 35 anos. Comparando as contribuições dos 32 países investigados, aqueles da América do Sul apresentaram baixo número de indexações (n= 26), poucos em cooperação (n= 7). O maior volume de publicações indexadas pelos pesquisadores trataram sobre a dinâmica e estrutura das assembléias aquáticas, teias e interações tróficas. Reservatórios e áreas alagadas têm recebido pouca atenção. Grande número de estudos compreeenderam abordagems de toda comunidade aquática e interações entre macrófitas, fitoplâncton, zooplâncton e peixes. Em síntese, concluimos que estudos enfatizando as interações tróficas mediadas pelas macrófitas poderão ser direcionados de maneira a atenuar assimetrias internacionais, encorajando o aumento da produtividade científica na América do Sul. O conhecimento sobre as interações tróficas em cascata tem sido desenvolvido com sucesso em diversos países cujas finalidades tem sido reestruturar comunidades e restaurar a qualidade da água de muitos ecossistemas.


Subject(s)
Plants , Botany , Bibliometrics , Food Chain , Hydrobiology , South America , Ecosystem , Aquatic Organisms
4.
Phys Chem Chem Phys ; 21(44): 24406-24418, 2019 Nov 28.
Article in English | MEDLINE | ID: mdl-31663556

ABSTRACT

A full-dimensional global potential-energy surface (PES) is first reported for ground-state doublet C3H using the combined-hyperbolic-inverse-power-representation (CHIPR) method and accurate ab initio energies extrapolated to the complete basis set limit. The PES is based on a many-body expansion-type development where the two-body and three-body energy terms are from our previously reported analytic potentials for C2H(2A') and C3(1A',3A'), while the effective four-body one is calibrated using an extension of the CHIPR formalism for tetratomics. The final form is shown to accurately reproduce all known stationary structures of the PES, some of which are unreported thus far, and their interconversion pathways. Moreover, it warrants by built-in construction the appropriate permutational symmetry and describes in a physically reasonable manner all long-range features and the correct asymptotic behavior at dissociation. Exploratory quasi-classical trajectory calculations for the reaction C2 + CH → C3 + H are also performed, yielding thermalized rate coefficients for temperatures up to 4000 K.

5.
J Phys Chem A ; 123(38): 8154-8169, 2019 Sep 26.
Article in English | MEDLINE | ID: mdl-31184891

ABSTRACT

We report the first global ab initio-based potential energy surface (PES) for ground-state triplet C3(3A') based on accurate energies extrapolated to the complete basis set (CBS) limit, and using the combined-hyperbolic-inverse-power-representation method for the analytical modeling. By relying on a cost-effective CBS(D,T) protocol, we ensure that the final form reproduces all topographical features of the PES, including its cyclic-linear isomerization barrier, with CBS(5,6)-quality. To partially account for the incompleteness of the N-electron basis and other minor effects, the available accurate experimental data on the relevant diatomics were used to obtain direct-fit curves that replace the theoretical ones in the many-body expansion. Besides describing properly long-range interactions at all asymptotic channels and permutational symmetry by built-in construction, the PES reported here reproduces the proper exothermicities at dissociation regions as well as the spectroscopy of the diatomic fragments. Bound vibrational state calculations in both linear and cyclic isomers have also been carried out, unveiling a good match of the available data on C3(ã 3Πu), while assisting with IR band positions for C3(3A2') that may serve as a guide for its laboratory and astronomical detection.

6.
J Phys Chem A ; 123(14): 3121-3130, 2019 Apr 11.
Article in English | MEDLINE | ID: mdl-30632758

ABSTRACT

The previously reported potential energy surfaces (PESs) of ground-state singlet C3 and triplet C4 are here utilized as input for the construction of approximate cluster expansions for larger Cκ (κ = 5-10) species. Relying primarily on the double many-body expansion (DMBE) approach, global potentials are obtained by summing the total interaction energies of all atomic subclusters up to four-body terms. The notable capability of the final forms in predicting good estimates of the linear global minima and their thermochemical/structural properties may provide important insights into the structure-determining nature of the (2 + 3 + 4) terms. The main difficulties and virtues in assessing Cκ's via DMBE theory are analyzed and new prospects given for the construction of global reliable PESs for the target species.

7.
Braz J Biol ; 79(4): 617-624, 2019.
Article in English | MEDLINE | ID: mdl-30379201

ABSTRACT

Aquatic macrophytes have a recognized role in ecosystem structuring and an important position in trophic cascades interactions, whose understanding is to improve water quality. In recent years, the number of studies on the role of aquatic macrophytes in trophic webs and interactions has increased, but South America has made little progress in research in the area. In this study, we investigated the main gaps and perspectives for future studies on macrophytes and trophic interactions, analyzing global publications, especially those conducted by South American researchers. We accessed publications using an international database (Thomson Reuters ISI-Web of Knowledge-(formerly Institute for Scientific Information)) from 1980 to 2015. We ranked each article by ecosystem and study approach, biological organization and interacting taxonomic groups (phytoplankton, periphyton, zooplankton, aquatic invertebrates, fish and birds), countries publishing in cooperation and affiliations. The results showed that published studies (n = 242) emphasizing aquatic plants in trophic interactions increased in 35 years. Comparing the contributions of the 32 countries investigated, those from South America as first affiliation, had few publications (n = 26) and in cooperation (n = 7). The largest volume of articles indexed by the researchers dealt with the dynamics and structure of aquatic assemblages, webs and trophic interactions. Ecosystems such reservoirs and wetlands have received little attention. Large numbers of studies have encompassed community-wide aquatic approaches, including in South American studies, the interactions between macrophytes, zooplankton and phytoplankton were the second most studied interactions of all indexed articles. Knowledge about trophic cascade and interactions has been successfully enhanced in several countries with the purpose of restructuring communities and restore water quality of many ecosystems. In summary, we conclude that studies in the area of trophic interactions mediated by macrophytes may be directed in a way to attenuate international asymmetries, encouraging the increase of scientific productivity in South America.


Subject(s)
Bibliometrics , Botany , Food Chain , Hydrobiology , Plants , Aquatic Organisms , Ecosystem , South America
8.
Phys Chem Chem Phys ; 20(15): 10319-10331, 2018 Apr 18.
Article in English | MEDLINE | ID: mdl-29610812

ABSTRACT

A new single-sheeted DMBE potential energy surface for ground-state C3 is reported. The novel analytical form accurately describes the three symmetry-equivalent C2v disjoint seams, in addition to the symmetry-required D3h one, over the entire configuration space. The present formalism warrants by built-in construction the confluence of the above crossings, and the rotation-in-plane of the C2v seams when the perimeter of the molecule fluctuates. Up to 1050 ab initio energies have been employed in the calibration procedure, of which 421 map the loci of intersection. The calculated energies have been scaled to account for the incompleteness of the basis set and truncation of the MRCI expansion, and fitted analytically with chemical accuracy. The novel form is shown to accurately mimic the region defined by the 4 conical intersections, while exhibiting similar attributes to the previously reported one [J. Chem. Phys., 2015, 143, 074302] at the regions of configuration space away from the crossing seams. Despite being mainly addressed to C3, the present approach should be applicable to adiabatic PESs of any X3 system experiencing similar topological attributes, in particular the small-linear-parameter Jahn-Teller molecules.

9.
Epidemiol Infect ; 146(5): 565-570, 2018 04.
Article in English | MEDLINE | ID: mdl-29463341

ABSTRACT

The aim of this study was to evaluate the distribution of cases and the social determinants associated with death from human visceral leishmaniasis (HVL) and VL-HIV co-infection in Belo Horizonte, Minas Gerais state, Brazil, between 2006 and 2013. Descriptive statistics and analysis of associations were performed using chi-square of the raised variables, such as sex, age, skin colour and schooling of cases of HVL. During the study period, there were 866 cases of HVL with 111 deaths in Belo Horizonte. Morbidity and lethality rates (LR) of HVL in Belo Horizonte remained high over almost all the years evaluated, with an average incidence rate of 4.18 cases/100 000 inhabitants and a LR of 11.16%. With respect to skin colour, it was found that people characterised as black or mulatto had higher morbidity, followed by white. Regarding schooling, LR was more prevalent among individuals with lower education. One of the social risk factors was co-infection with HIV, which was present in many cases of HVL. Furthermore, it was found that older age and the male sex were also risk factors for death from HVL in Belo Horizonte.


Subject(s)
Coinfection/epidemiology , HIV Infections/epidemiology , Leishmaniasis, Visceral/epidemiology , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Brazil/epidemiology , Child , Child, Preschool , Coinfection/parasitology , Coinfection/virology , Female , HIV Infections/virology , Humans , Incidence , Infant , Infant, Newborn , Leishmaniasis, Visceral/mortality , Leishmaniasis, Visceral/parasitology , Male , Middle Aged , Morbidity , Prevalence , Risk Factors , Sex Factors , Socioeconomic Factors , Young Adult
10.
Philos Trans A Math Phys Eng Sci ; 376(2115)2018 Mar 13.
Article in English | MEDLINE | ID: mdl-29431687

ABSTRACT

The major aspects of the C2, C3 and C4 elemental carbon clusters are surveyed. For C2, a brief analysis of its current status is presented. Regarding C3, the most recent results obtained in our group are reviewed with emphasis on modelling its potential energy surface which is particularly complicated due to the presence of multiple conical intersections. As for C4, the most stable isomeric forms of both triplet and singlet spin states and their possible interconversion pathways are examined afresh by means of accurate ab initio calculations. The main strategies for modelling the ground triplet C4 potential are also discussed. Starting from a truncated cluster expansion and a previously reported DMBE form for C3, an approximate four-body term is calibrated from the ab initio energies. The final six-dimensional global DMBE form so obtained reproduces all known topographical aspects while providing an accurate description of the C4 linear-rhombic isomerization pathway. It is therefore commended for both spectroscopic and reaction dynamics studies.This article is part of the theme issue 'Modern theoretical chemistry'.

11.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467229

ABSTRACT

Abstract Aquatic macrophytes have a recognized role in ecosystem structuring and an important position in trophic cascades interactions, whose understanding is to improve water quality. In recent years, the number of studies on the role of aquatic macrophytes in trophic webs and interactions has increased, but South America has made little progress in research in the area. In this study, we investigated the main gaps and perspectives for future studies on macrophytes and trophic interactions, analyzing global publications, especially those conducted by South American researchers. We accessed publications using an international database (Thomson Reuters ISI-Web of Knowledge-(formerly Institute for Scientific Information)) from 1980 to 2015. We ranked each article by ecosystem and study approach, biological organization and interacting taxonomic groups (phytoplankton, periphyton, zooplankton, aquatic invertebrates, fish and birds), countries publishing in cooperation and affiliations. The results showed that published studies (n = 242) emphasizing aquatic plants in trophic interactions increased in 35 years. Comparing the contributions of the 32 countries investigated, those from South America as first affiliation, had few publications (n = 26) and in cooperation (n = 7). The largest volume of articles indexed by the researchers dealt with the dynamics and structure of aquatic assemblages, webs and trophic interactions. Ecosystems such reservoirs and wetlands have received little attention. Large numbers of studies have encompassed community-wide aquatic approaches, including in South American studies, the interactions between macrophytes, zooplankton and phytoplankton were the second most studied interactions of all indexed articles. Knowledge about trophic cascade and interactions has been successfully enhanced in several countries with the purpose of restructuring communities and restore water quality of many ecosystems. In summary, we conclude that studies in the area of trophic interactions mediated by macrophytes may be directed in a way to attenuate international asymmetries, encouraging the increase of scientific productivity in South America.


Resumo Macrófitas aquáticas tem reconhecida função na estruturação de ecossistemas e importante papel nas interações tróficas em cascata, cujo entendimento é chave para melhorar a qualidade da água. Nos últimos anos, o número de estudos sobre o papel das macrófitas aquáticas nas interações e teia trófica aumentaram mas, a América do Sul progrediu pouco em pesquisas na área. Nesse estudo investigamos as principais lacunas e perspectivas para estudos futuros sobre macrófitas e interações tróficas analisando publicações mundiais, especialmente aquelas conduzidas por pesquisadores sul-americanos. Acessamos publicações usando base de dados internacional (Thomson Reuters ISI Web of Knowledge) entre 1980 a 2015. Computamos para cada artigo a organização biológica e grupos taxonômicos em interação (fitoplâncton, perifíton, zooplâncton, invertebrados aquáticos, peixes e aves), ecossistema estudado e abordagem de pesquisa, a cooperação entre países da América do Sul e demais, além das filiações. Os resultados mostraram que estudos publicados (n = 242) enfatizando plantas aquáticas em interações tróficas cresceram em 35 anos. Comparando as contribuições dos 32 países investigados, aqueles da América do Sul apresentaram baixo número de indexações (n= 26), poucos em cooperação (n= 7). O maior volume de publicações indexadas pelos pesquisadores trataram sobre a dinâmica e estrutura das assembléias aquáticas, teias e interações tróficas. Reservatórios e áreas alagadas têm recebido pouca atenção. Grande número de estudos compreeenderam abordagems de toda comunidade aquática e interações entre macrófitas, fitoplâncton, zooplâncton e peixes. Em síntese, concluimos que estudos enfatizando as interações tróficas mediadas pelas macrófitas poderão ser direcionados de maneira a atenuar assimetrias internacionais, encorajando o aumento da produtividade científica na América do Sul. O conhecimento sobre as interações tróficas em cascata tem sido desenvolvido com sucesso em diversos países cujas finalidades tem sido reestruturar comunidades e restaurar a qualidade da água de muitos ecossistemas.

12.
J Chem Phys ; 144(6): 064309, 2016 Feb 14.
Article in English | MEDLINE | ID: mdl-26874490

ABSTRACT

The combined Jahn-Teller plus pseudo-Jahn-Teller [(E'+A1')⊗e'] problem is discussed for the tricarbon radical (C3) by means of ab initio calculations at the multireference configuration interaction level of theory. For the (1)E' electronic state arising from a e'(2) valence configuration, three additional symmetry-equivalent C2v seams are found to lie in close proximity to the D3h symmetry-required seam over the entire range of the breathing coordinate here considered. As the perimeter of the molecule increases, the C2v disjoint seams approach the D3h one almost linearly and ultimately coalesce with it at Q1 = 5.005 a0, thence forming an intersection node or confluence. By further increasing the size of the molecular triangle, the C2v seams get rotated by ±π in the g-h plane. A three-state vibronic Hamiltonian is also proposed to model locally the title system and shown to accurately mimic the calculated data over the region close to the minimum energy crossing point. No net geometric phase effect is observed when the associated electronic wave functions are adiabatically transported along closed paths encircling the four singularity points. For all paths enclosing the intersection node, the sign reversal criterion is shown to be not fulfilled, even for infinitesimal loops. The results so obtained are expected to be valid for other ring systems experiencing similar topological attributes.

13.
N Z Dent J ; 111(3): 119-22, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26502601

ABSTRACT

UNLABELLED: Background: This study examined the spatial accessibility of the population of metropolitan Auckland, New Zealand to the bus network, to connect them to primary health providers, in this case doctors (GP) and dentists. Analysis of accessibility by ethnic identity and socio-economic status were also carried out, because of existing health inequalities along these dimensions. The underlying hypothesis was that most people would live within easy reach of primary health providers, or easy bus transport to such providers. METHODS: An integrated geographic model of bus transport routes and stops, with population and primary health providers (medical. and dental practices) was developed and analysed. RESULTS: Although the network of buses in metropolitan Auckland is substantial and robust it was evident that many people live more than 150 metres from a stop. CONCLUSION: Improving the access to bus stops, particularly in areas of high primary health care need (doctors and dentists), would certainly be an opportunity to enhance spatial access in a growing metropolitan area.


Subject(s)
Dentists/supply & distribution , Health Services Accessibility , Physicians/supply & distribution , Primary Health Care , Transportation , Geographic Information Systems , Geographic Mapping , Humans , New Zealand , Professional Practice Location , Urban Population
14.
J Chem Phys ; 143(7): 074302, 2015 Aug 21.
Article in English | MEDLINE | ID: mdl-26298129

ABSTRACT

A fully ab initio-based potential energy surface is first reported for the ground electronic state of the C3 radical using the double many-body expansion (DMBE) method. The DMBE form so obtained mimics the full set of energies calculated at the multireference configuration interaction level of theory with chemical accuracy. To account for the incompleteness of the one- and N-electron bases, the calculated external correlation energies have been scaled prior to the fitting procedure via DMBE-scaled external correlation method. Furthermore, the novel potential energy surface reproduces accurately dissociation energies, diatomic potentials, long-range interactions at all asymptotic channels, and the correct topological behavior at the region of 4 conical intersections with the partner state of the same symmetry near equilateral triangular geometries due to combined Jahn-Teller (E' ⊗ e') plus pseudo-Jahn-Teller [(E'+A1')⊗e'] interactions. Rovibrational calculations have also been performed, unveiling a good match of the vibrational spectrum of C3 for 53 calculated levels. The present DMBE form is, therefore, commended for both spectroscopic and reaction dynamics studies, some also performed in the present work.

15.
Community Dent Health ; 31(2): 85-90, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25055605

ABSTRACT

OBJECTIVE: To model the geographic distribution of current (and treated) dental decay on a high-resolution geographic basis for the Auckland region of New Zealand. BASIC RESEARCH DESIGN: The application of matrix-based mathematics to modelling adult dental disease-based on known population risk profiles to provide a detailed map of the dental caries distribution for the greater Auckland region. RESULTS: Of the 29 million teeth in adults in the region some 1.2 million (4%) are suffering decay whilst 7.2 million (25%) have previously suffered decay and are now restored. CONCLUSIONS: The model provides a high-resolution picture of where the disease burden lies geographically and presents to health planners a method for developing future service plans.


Subject(s)
Dental Caries/epidemiology , Urban Health/statistics & numerical data , Adolescent , Adult , Aged , Asian People/statistics & numerical data , Cost of Illness , DMF Index , Dental Caries/ethnology , Dental Restoration, Permanent/statistics & numerical data , Geographic Mapping , Humans , Middle Aged , Native Hawaiian or Other Pacific Islander/statistics & numerical data , New Zealand/epidemiology , New Zealand/ethnology , Risk Assessment , Social Class , Tooth Loss/epidemiology , Tooth Loss/ethnology , Vulnerable Populations/statistics & numerical data , White People/statistics & numerical data , Young Adult
16.
Community Dent Health ; 30(3): 149-54, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24151788

ABSTRACT

BACKGROUND: Little detail is known about the geographical catchment areas covered by dental hospitals, with no previous Australian studies of this kind. The aim of this study was to assess the geographical distribution of public dental emergency patients and their socioeconomic status to define catchment zones for a dental hospital. METHODS: All patients requesting emergency dental care at the Royal Dental Hospital Melbourne, meeting the inclusion criteria, in calendar years 2006 and 2010 were included in the sample. Geographic information systems tools were used to locate and link each patient address to the socioeconomic data. RESULTS: For both 2006 and 2010 95% of the patients were living within 50km of the hospital. In 2006, most of the patients seeking care lived within a 15km radius of the dental hospital whilst in 2010 that distance increased somewhat. Patients from areas with similar socioeconomic status living more than 10km away from the hospital had poorer access to dental emergency treatment. CONCLUSIONS: The hospital had a surprisingly large catchment zone that overlapped those of smaller community-based clinics.


Subject(s)
Catchment Area, Health/statistics & numerical data , Dental Care/statistics & numerical data , Dental Clinics/statistics & numerical data , Emergency Service, Hospital/statistics & numerical data , Emergency Treatment/statistics & numerical data , Health Services Accessibility , Urban Population/statistics & numerical data , Censuses , Demography , Geographic Information Systems , Hospitals, Urban/statistics & numerical data , Humans , Residence Characteristics/statistics & numerical data , Social Class , Victoria
17.
Epidemiol Infect ; 141(11): 2286-93, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23419686

ABSTRACT

This study was conducted to determine the seroprevalence of anti-Neospora caninum antibodies and to investigate the risk factors related to seroprevalence in dogs from urban and rural areas with distinct economic activities (milk and coffee production) in Minas Gerais state, Brazil. For this purpose, blood samples from 703 dogs were collected and questionnaires addressing epidemiological aspects were completed by dog-owners. The sera were analysed for anti-N. caninum antibodies by indirect fluorescent antibody tests (IFAT ≥ 1:50). Association between epidemiological aspects and seropositivity in dogs was evaluated with multivariate logistic regression models. A total of 80 (11·4%) dogs tested positive for N. caninum. In the multivariate logistic regression models, dogs aged >4 years, dogs used as guard dogs, dogs that spontaneously hunt, and history of bovine abortion were found to be greater risk factors for canine N. caninum infection. When we considered only dogs from rural areas, an association with seroprevalence was seen for milk farms, dogs not fed with commercial food, dogs that hunt, and dogs used as guard dogs.


Subject(s)
Coccidiosis/veterinary , Coffea , Dog Diseases/parasitology , Milk , Neospora/isolation & purification , Aging , Agriculture , Animals , Brazil/epidemiology , Cattle , Coccidiosis/epidemiology , Coccidiosis/parasitology , Dog Diseases/epidemiology , Dogs , Fluorescent Antibody Technique, Indirect , Logistic Models , Multivariate Analysis , Odds Ratio , Risk , Risk Factors , Rural Population , Seroepidemiologic Studies , Surveys and Questionnaires , Urban Population
18.
Arq. bras. med. vet. zootec ; 64(6): 1621-1628, Dec. 2012. ilus, tab
Article in Portuguese | LILACS | ID: lil-660233

ABSTRACT

Esta pesquisa teve como objetivo realizar o levantamento das dificuldades encontradas pelos pecuaristas que aderiram ao Serviço de Rastreabilidade da Cadeia Produtiva de Bovinos e Bubalinos (Novo SISBOV). Elaborou-se um formulário qualitativo semiestruturado, contendo 37 questões. Foram entrevistados 130 produtores de gado de corte em três grandes exposições agropecuárias durante o ano de 2009. Desses, aproximadamente 17% (22 produtores) haviam aderido ao novo SISBOV. Foram entrevistados mais 49 pecuaristas em suas respectivas fazendas rastreadas, totalizando assim 179 entrevistas. As principais dificuldades encontradas pelos pecuaristas foram: mudanças frequentes nas normas do novo SISBOV, perda de elemento de identificação, remuneração inadequada pelos animais rastreados por parte dos frigoríficos e instabilidade de mercado.


This research aimed to conduct a survey of the difficulties encountered by farmers who joined the Service of Supply Chain Traceability of Cattle and Buffaloes (New SISBOV). A semi-structured qualitative form containing thirty-seven questions was elaborated. We interviewed 130 beef cattle farmers farming in three major exhibitions during year 2009, among which 17% (22 farmers) had joined the new SISBOV. We interviewed over 49 farmers in their screened farms, thus totaling 179 interviews. The main difficulties encountered by farmers were: frequent changes in new SISBOV rules, loss of proof of identity, inadequate remuneration for animals tracked by the stores and market instability.


Subject(s)
Animals , Cattle , Animal Husbandry/organization & administration , Livestock Industry , Food Security
19.
Pediatr Cardiol ; 26(5): 720-3, 2005.
Article in English | MEDLINE | ID: mdl-15690231

ABSTRACT

Gastroesophageal reflux is very common in childhood. If conservative procedures fail to relieve it, the use of a potent antiemetic agent that facilitates gastric motility and emptying, such as domperidone, is justified. We report a 4-month-old child who presented with QT interval prolongation after the oral use of domperidone, which normalized after the drug was discontinued.


Subject(s)
Antiemetics/adverse effects , Domperidone/adverse effects , Long QT Syndrome/chemically induced , Electrocardiography , Gastroesophageal Reflux/drug therapy , Humans , Infant , Long QT Syndrome/diagnosis , Long QT Syndrome/physiopathology , Male , Myocardial Contraction/drug effects
20.
Ann N Y Acad Sci ; 1063: 356-7, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16481542

ABSTRACT

The authors describe cases of Brazilian spotted fever (BSF) diagnosed in Minas Gerais state, Brazil, by the Minas Gerais Public Health Laboratory, Ezequiel Dias Foundation from 1995 to 2004. In addition they present three cases of human Rickettsia felis rickettsiosis from Minas Gerais diagnosed in France in 1999, and the first two suspected cases of human monocytic ehrlichiosis (HME) diagnosed in Ezequiel Dias Foundation in 2001. In both cases a differential diagnose was made with BSF.


Subject(s)
Rickettsia Infections/epidemiology , Brazil/epidemiology , Ehrlichiosis/epidemiology , Humans
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