Cross-continental comparative experiences of wastewater surveillance and a vision for the 21st century.

The COVID-19 pandemic has brought the epidemiological value of monitoring wastewater into sharp focus. The challenges of implementing and optimising wastewater monitoring vary significantly from one region to another, often due to the array of different wastewater systems around the globe, as well as the availability of resources to undertake the required analyses (e.g. laboratory infrastructure and expertise). Here we reflect on the local and shared challenges of implementing a SARS-CoV-2 monitoring programme in two geographically and socio-economically distinct regions, São Paulo state (Brazil) and Wales (UK), focusing on design, laboratory methods and data analysis, and identifying potential guiding principles for wastewater surveillance fit for the 21st century. Our results highlight the historical nature of region-specific challenges to the implementation of wastewater surveillance, including previous experience of using wastewater surveillance, stakeholders involved, and nature of wastewater infrastructure. Building on those challenges, we then highlight what an ideal programme would look like if restrictions such as resource were not a constraint. Finally, we demonstrate the value of bringing multidisciplinary skills and international networks together for effective wastewater surveillance.

Role of defects in the mechanical properties of graphene-copper heterostructures.

Through molecular dynamics simulations of tensile tests, the role that vacancies and Stone-Wales defects play in the mechanical properties of sandwich-like heterostructures, composed by graphene and two symmetric copper layers at nanoscale, is studied. The dependence on the armchair and zigzag chiralities of the graphene layer is also investigated. During elastic deformation, defects negatively affect the mechanical response. However, defective systems can show an improvement of the plastic properties. Vacancies have a stronger impact compared to Stone-Wales defects. Elasticity, toughness, and ductility are enhanced along the zigzag chirality, while stiffness is improved along the armchair direction. The Poisson's ratio was calculated for all graphene-copper heterostructures. At a critical strain it becomes negative along the thickness direction, preserving the auxetic property at higher strains. In general, the behavior is governed by the graphene response. Our findings can be useful to understand the strengthening mechanism induced by this two-dimensional material in metals like copper and for the design of similar systems.

Estimation of greenhouse gases shadow price in the English and Welsh water industry.

Moving to a more sustainable and low-carbon footprint urban water cycle is essential in the light of climate change. In this paper, we estimate the implicit cost of reducing greenhouse gas (GHG) emissions for several English and Welsh water companies from 2013 to 2019. Using econometric techniques, we compute the shadow prices of direct and indirect CO2 emissions associated with the provision of drinking water. This methodological approach also allows us to investigate the impact of a set of environmental variables on the costs of water companies and therefore on the costs of reducing GHG emissions. We then compute the returns to scale, technical change, and technical efficiency of the water companies. The empirical results show the following: (1) the average shadow price of CO2 across years was 0.114 £/kgCO2, which means that the English and Welsh water industry needs to spend an extra £0.114 in operating expenditure to prevent the emission of one kilogramme of CO2; (2) the cost of reducing GHG emissions is very variable among water companies and across years; (3) water taken from boreholes and average pumping head increases cost requirements and therefore the inefficiency of water companies; and (4) the water industry may lower its production costs and thus the costs of reducing GHG emissions by improving its daily operations and adopting new technologies. From a policy perspective, this study evidences that in the English and Welsh water industry, a market-based approach may be more suitable to reduce GHG emissions than a carbon tax policy.

Doxorubicin Encapsulation in Carbon Nanotubes Having Haeckelite or Stone-Wales Defects as Drug Carriers: A Molecular Dynamics Approach.

Doxorubicin (DOX), a recognized anticancer drug, forms stable associations with carbon nanotubes (CNTs). CNTs when properly functionalized have the ability to anchor directly in cancerous tumors where the release of the drug occurs thanks to the tumor slightly acidic pH. Herein, we study the armchair and zigzag CNTs with Stone-Wales (SW) defects to rank their ability to encapsulate DOX by determining the DOX-CNT binding free energies using the MM/PBSA and MM/GBSA methods implemented in AMBER16. We investigate also the chiral CNTs with haeckelite defects. Each haeckelite defect consists of a pair of square and octagonal rings. The armchair and zigzag CNT with SW defects and chiral nanotubes with haeckelite defects predict DOX-CNT interactions that depend on the length of the nanotube, the number of present defects and nitrogen doping. Chiral nanotubes having two haeckelite defects reveal a clear dependence on the nitrogen content with DOX-CNT interaction forces decreasing in the order 0N > 4N > 8N. These results contribute to a further understanding of drug-nanotube interactions and to the design of new drug delivery systems based on CNTs.

Municipal Responses to COVID-19: the case of library closures in New South Wales local government / Respostas de municípios à COVID-19: o caso do fechamento das bibliotecas em Nova Gales do Sul / Respuestas municipales a la COVID-19: El caso del cierre de las bibliotecas de Nueva Gales del Sur

Abstract In response to the COVID-19 pandemic, the New South Wales (NSW) government ordered the closure of all municipal libraries in order to limit the impact of the contagion. As a result, 372 public libraries in NSW ceased operation on the 23rd March 2020. While the closure of public libraries will undoubtedly contribute to restricting the spread of the coronavirus, given the pivotal role played by municipal libraries in local communities, as well as the special characteristics of library patrons, it will have other negative consequences. In this paper we consider the impact of the closure of municipal libraries in NSW from two perspectives: (a) its effect on the fiscal circumstances of local authorities and (b) its impact on the spread of the corona contagion as well as its broader effects on local community wellbeing. We conclude that rather than complete closure, partial constraints on library use should have been considered.

Resumo Em resposta à pandemia da COVID-19, o governo de Nova Gales do Sul (NGS), na Austrália, ordenou o fechamento de todas as bibliotecas municipais com o objetivo de limitar os impactos da contaminação. Como resultado, 372 bibliotecas públicas pararam suas atividades no dia 23 de março de 2020. Embora o fechamento de bibliotecas públicas certamente contribui para restringir a propagação do vírus, deve-se considerar as consequências negativas dessa medida, dado o papel central desempenhado pelas bibliotecas municipais nas comunidades locais e as características particulares dos usuários. Este artigo discute os impactos do encerramento das atividades das bibliotecas em NGS através de duas perspectivas: (a) a partir do efeito da medida na situação fiscal dos municípios; e (b) o seu impacto em relação a propagação do vírus e seus efeitos mais amplos no bem-estar das comunidades locais. O estudo conclui que restrições parciais no acesso aos serviços deveriam ter sido consideradas como alternativa ao fechamento total das bibliotecas.

Resumen En respuesta a la pandemia de COVID-19, el gobierno de Nueva Gales del Sur (NSW), Australia, ordenó el cierre de todas las bibliotecas municipales para limitar el impacto de la contaminación. Como resultado, 372 bibliotecas públicas de NSW cesaron sus operaciones el 23 de marzo del 2020. Aunque el cierre de las bibliotecas públicas indudablemente contribuirá a restringir la proliferación del coronavirus, se deben considerar las consecuencias negativas de dicha medida, dado el rol esencial de las bibliotecas municipales en las comunidades locales y las características particulares de sus usuarios. Este artículo discute los impactos del cese de actividades de las bibliotecas municipales de NSW desde dos perspectivas: (a) su efecto en la situación fiscal de los municipios y (b) su impacto en la proliferación del coronavirus, así como sus efectos más amplios en el bienestar de las comunidades locales. El estudio concluye que, en lugar de un cese total, se deberían haber considerado restricciones parciales al acceso las bibliotecas.

Estimating technical efficiency and allocative distortions of water companies: evidence from the English and Welsh water and sewerage industry.

Regulated water industries need to improve their technical efficiency and allocate their resources efficiently. This is the case of the water industry in England and Wales which was privatized in 1989, and the method of price cap regulation was implemented. This study uses an input distance function system approach to estimate the technical efficiency and distortions in the choice of input mixes for the English and Welsh water and sewerage companies (WaSCs) over the years 1991-2016. The results indicated that an average WaSC was 75.3% technically efficient which means that inputs could be reduced by 24.7% keeping the level of output constant. On average, the input mix was considered to be allocated inefficiently as there was an over-utilization of capital and other inputs relative to employment. Moreover, the low degree of substitutability among inputs implied that reducing allocative inefficiency could be costly. The findings of our study is of interest to policy makers who want to implement effective policies to improve efficiency in the water industry.

A dispersion-corrected density functional theory study of the noncovalent interactions between nucleobases and carbon nanotube models containing stone-wales defects.

The noncovalent bonding between nucleobases (NBs) and Stone-Wales (SW) defect-containing closed-end single-walled carbon nanotubes (SWNTs) was theoretically studied in the framework of density function theory using a dispersion-corrected functional PBE-G06/DNP. The models employed in this study were armchair nanotube (ANT) (5,5) and zigzag nanotube (ZNT) (10,0), which incorporated SW defects in different orientations. In one of them, the (7,7) junction is tilted with respect to SWNT axis (ANT-t and ZNT-t), whereas in ANT-p and ZNT-p models the (7,7) junction is parallel and perpendicular to the axis, respectively. The binding energies for uracil, thymine, cytosine, 5-methylcytosine, adenine, and guanine interacting with the defect-containing nanotube models were compared to the values previously obtained with the same calculation technique for the case of defect-free SWNTs, both in the gas phase (vacuum) and in aqueous medium. For most models, the interaction strength tends to be higher for purine than for pyrimidine complexes, with a clear exception of the systems including ZNT-p, both in vacuum and in aqueous medium. As it could be expected, the binding strength in the latter case is lower as compared to that in vacuum, roughly by 2-4 kcal/mol, due to the implicit inclusion of a medium (i.e., water) via the conductor-like screening model model. The closest contacts between NBs and SWNT models, frontier orbital distribution, and highest-occupied molecular orbital-lowest-unoccupied molecular orbital gap energies are analyzed as well. © 2019 Wiley Periodicals, Inc.

Impact of environmental variables on the efficiency of water companies in England and Wales: a double-bootstrap approach.

An important aspect of the regulatory process is the performance comparison of regulated firms. This exists in regulated industries where tariffs are determined through a benchmarking process such as the English and Welsh water industry. A double-bootstrap data envelopment analysis (DEA) approach was applied to overcome the uncertainty in efficiency scores and to reveal the influence of environmental variables on 18 water companies in England and Wales during the 2001-2016 period. The results showed that bias and bias-corrected efficiency scores lead to changes in the water companies' rankings. This reveals the importance of using reliable methodologies to support the decision-making process. Higher levels of average pumping head, leakage, and abstraction of water from reservoirs lead to lower efficiency. In contrast, increased population density leads to larger efficiency. We also link the results from the efficiency of water companies with the regulatory cycle. Our findings can be useful to policy makers for them to better understand water utilities' performance and to aid them in reshaping their current policies and practices to improve efficiency and provide better service to customers.

Flexible versus common technology to estimate economies of scale and scope in the water and sewerage industry: an application to England and Wales.

The water industry presents several structures in different countries and also within countries. Hence, several studies have been conducted to evaluate the presence of economies of scope and scale in the water industry leading to inconclusive results. The lack of a common methodology has been identified as an important factor contributing to divergent conclusions. This paper evaluates, for the first time, the presence of economies of scale and scope in the water industry using a flexible technology approach integrating operational and exogenous variables of the water companies in the cost functions. The empirical application carried out for the English and Welsh water industry evidenced that the inclusion of exogenous variables accounts for significant differences in economies of scale and scope. Moreover, completely different results were obtained when the economies of scale and scope were estimated using common and flexible technology methodological approaches. The findings of this study reveal the importance of using an appropriate methodology to support policy decision-making processes to promote sustainable urban water activities.

Internação Psiquiátrica Involuntária: estudo comparativo das Normas de Saúde Mental do Brasil e Inglaterra/País de Gales / Involuntary Psychiatric Admission: comparative study of Mental Health legislation from Brazil and England/Wales

A internação involuntária é uma medida controversa que pode levar a violação de vários direitos humanos. Nessa perspectiva, faz-se necessária uma legislação para definir e limitar as circunstâncias em que isso pode ocorrer. Políticas e leis bem formuladas podem promover o desenvolvimento de serviços acessíveis na comunidade, estimular campanhas de sensibilização e de educação, e estabelecer mecanismos legais e de supervisão para prevenir violações aos direitos humanos. Nesse contexto, este estudo descritivo-comparativo apresentou como objetivo analisar as semelhanças e diferenças entre as legislações em saúde mental relacionadas à internação psiquiátrica involuntária no Brasil e Inglaterra/País de Gales. Utilizou-se para o levantamento de dados de pesquisa bibliográfica e pesquisa documental. A análise foi realizada a partir da Lista de Checagem da Organização Mundial da Saúde (OMS) para a Legislação de Saúde Mental. Para a etapa de comparação dos dados das duas jurisdições, foi utilizado o método comparativo. Sobre os resultados da comparação da Lista de Checagem da OMS com as legislações do Brasil e Inglaterra/País de Gales, na legislação brasileira foram encontrados 52 (31,32%) dos 166 padrões da OMS, enquanto que na legislação da Inglaterra/País de Gales foram encontrados 90 (54,2%). A partir da análise foi possível concluir que: a legislação da Inglaterra/País de Gales traz procedimentos mais claros e detalhados sobre "internação involuntária" e possui "mecanismos de fiscalização" mais eficazes do que o Brasil; apesar das lacunas quanto aos procedimentos para apelações contra decisões de incapacidade e a revisão da necessidade de um tutor, a legislação apresenta uma boa cobertura sobre "competência, capacidade e tutela", tema de elevada importância, principalmente após a ratificação da CDPD, e que o Brasil não aborda em sua legislação; a legislação brasileira elenca um rol maior de "direitos fundamentais", porém não prevê "penalidades" quanto ao descumprimento desses direitos. Já a Inglaterra/País de Gales cobre amplamente essa questão. As principais semelhanças entre Brasil e Inglaterra/País de Gales referem-se aos padrões que necessitam de revisão: "Pacientes voluntários", situações de emergência", direitos econômicos e sociais", "questões civis" e "grupos vulneráveis". Ambas jurisdições também apresentam o mesmo nível de cobertura quanto a "pesquisa clínica e experimental", e "tratamentos especiais, isolamento e restrições". Em suma, a análise das legislações de saúde mental apresentada neste trabalho sugere que documentos internacionais de direitos humanos, como o Livro de Recursos OMS, são instrumentos importantes e que podem nortear a construção de legislações. É necessário também que a formulação de leis e políticas de saúde mental esteja articulada com os documentos internacionais de direitos humanos como a CDPD. Espera-se que o presente estudo traga a tona a reflexão das autoridades competentes sobre a necessidade de solicitar auditorias mais profundas no âmbito da legislação nacional de saúde mental, realizadas por comitês multidisciplinares, como recomendado pela OMS. A legislação de saúde mental deve estar num processo de constante evolução, centrada na busca da consolidação dos direitos das pessoas com transtornos mentais

Involuntary admission is a controversial measure that can lead to violation of various human rights. From this perspective, legislation must define and limit the circumstances in which this may occur. Well-formulated policies and laws can promote the development of accessible services in the community, stimulate awareness and education campaigns, and establish legal and supervisory mechanisms to prevent human rights violations. In this context, this descriptive- comparative aimed at analyzing the similarities and differences between the mental health' laws related to involuntary psychiatric admission in Brazil and England/Wales. In order to collect data, the author used bibliographic and documentary research. The analysis was based on the World Health Organization's Checklist on Mental Heallth Legislation. To compare data from the two jurisdictions, the author used the comparative method. Results comparing the WHO Checklist with the laws from Brazil and England/Wales showed that the Brazilian legislation meets 52 (31.32%) of the 166 WHO standards, while legislation in England/Wales meets 90 (54.2%). Some conclusions resulted from the analysis: the law from England/Wales establishes clearer and detailed procedures for "involuntary admissions" and has "oversight and review mechanisms" more effective than Brazil; despite the shortcomings in the procedures for appeals against disability decisions and the review of the need for a guardian, the legislation presents a medium compliance of "competence, capacity and protection", a subject of high importance, especially after the ratification of the CRPD, and Brazil does not address these issues in its legislation; Brazilian establishes a larger list of "fundamental rights", but does not provide "penalties" for the breach of those rights, while England/Wales meets WHO criteria in relation to this issue. The main similarities between Brazil and England/Wales refer to standards that require review: "voluntary patients", "emergency treatment", "economic and social rights", "civil issues" and "protection of vulnerable groups." Both jurisdictions also have the same level of compliance regarding "clinical and experimental research", and "special treatments, seclusion and restraint". In sum, the analysis of mental health legislation presented in this paper suggests that international human rights documents, such as the WHO Resource Book, are important tools which can guide the construction of legislation. It is also necessary that the formulation of mental health laws and policies are articulated with international human rights documents such as the CRPD. In this sense, this study may bring light for a reflection from competent authorities on the need to have audits for national mental health legislations, carried out by multidisciplinary committees, as recommended by WHO. Mental health legislation should be in a process of constant evolution, focusing on the search for the consolidation of rights of people with mental disorders

Determining diatom ecotones and their relationship to terrestrial ecoregion designations in the central Canadian Arctic Islands.

Ecotones are key areas for the detection of global change because many are predicted to move with shifts in climate. Prince of Wales Island, in the Canadian Arctic Archipelago, spans the transition between mid- to high-Arctic ecoregions. We analyzed limnological variables and recent diatom assemblages from its lakes and ponds to determine if assemblages reflected this ecotone. Limnological gradients were short, and water chemistry explained 20.0% of diatom variance in a redundancy analysis (RDA), driven primarily by dissolved organic carbon, Ca and SO4 . Most taxa were small, benthic forms; key taxa such as planktonic Cyclotella species were restricted to the warmer, southern portion of the study area, while benthic Staurosirella were associated with larger, ice-dominated lakes. Nonetheless, there were no significant changes in diatom assemblages across the mid- to high-Arctic ecoregion boundary. We combined our data set with one from nearby Cornwallis Island to expand the study area and lengthen its environmental gradients. Within this expanded data set, 40.6% of the diatom variance was explained by a combination of water chemistry and geographic variables, and significant relationships were revealed between diatom distributions and key limnological variables, including pH, specific conductivity, and chl-a. Using principal coordinates analysis, we estimated community turnover with latitude and applied piecewise linear regression to determine diatom ecotone positions. A pronounced transition was present between Prince of Wales Island and the colder, more northerly Cornwallis Island. These data will be important in detecting any future northward ecotone movement in response to predicted Arctic climate warming in this highly sensitive region.

Risk factors and costs of hospital admissions in first year of life: a population-based study.

OBJECTIVE: To identify the maternal and infant risk factors associated with hospital admission in the first year and estimate the associated costs of infant hospitalization. STUDY DESIGN: Data from the Perinatal Data Collection for 599753 liveborn infants born in New South Wales, Australia, 2001-2007 were linked to hospital admission data. Logistic regression models were used to investigate the association between maternal and infant characteristics and admission to hospital once, and more than once in the first year; and average costs for total hospital admissions were calculated. RESULTS: Almost 15% of infants were admitted to hospital once and 4.6% had multiple admissions. Gestational age <37 weeks was most strongly associated with admission to hospital once, and severe neonatal morbidity was most strongly associated with multiple admissions (aOR 2.60; 95% CI 2.47-2.75). Infants born <39 weeks gestational age, to adolescent mothers, mothers who smoke, are not married, or had a planned delivery also have an increased risk of multiple admissions. Infants with severe neonatal morbidity contributed 27% of total infant hospital costs. With each increasing week of gestational age the mean annual cost decreased on average 10% and 27% for infants with and without neonatal morbidity respectively. CONCLUSIONS: Infants born with severe neonatal morbidity have increased hospitalizations in the first year; however, the majority of burden on health system is by infants without severe neonatal morbidity. Hospitalizations, and associated costs, increased with decreasing gestational age, even for infants born at 37-38 weeks. Targeted public health strategies may reduce the burden of infant hospitalizations.

Maternal mortality in England and Wales 1970-1985: an analysis by country of birth.

OBJECTIVE: To determine the risk of maternal mortality in immigrants to England and Wales. DESIGN: Analysis of death registrations, 1970-1985, by country of birth. SETTING: England and Wales. POPULATION: Women dying in England and Wales during pregnancy, childbirth or the puerperium, or dying from malignant tumour of the placenta. MAIN OUTCOME MEASURES: The risk of dying in pregnancy, childbirth or the puerperium, adjusted for age and year of death, and the risk of cause-specific death, adjusted for age, in immigrants compared with women born in England and Wales. RESULTS: Women born in West Africa (relative risk 10.3; 95% CI 8.0-13.2) and the Caribbean (4.6; 3.8-5.7) were at very elevated risk of maternal death and of the main causes of death. Women from Southern Asia (1.6; 1.3-2.0) and "Europe and the USSR' (1.7; 1.2-2.3) were at moderate risk. Adjustment for year of death increased the estimates of risk and women born in the "Rest of the World' and Scotland were at significantly elevated risk. CONCLUSIONS: An increased incidence of obstetric conditions in immigrant groups may account for the elevated risk but it is also possible that differences in care may account for some of the additional risk. The pattern of increased risk does not appear to be explicable by the parity or social class distribution of immigrants as far as data are available on these. Research is required into the aetiology of the differential incidence of obstetric disease. The collection of routine mortality data which include maternal reproductive and social factors would elucidate the significance of such factors to maternal health. Further investigation into possible differences in the process of antenatal care between immigrants and non-immigrants is required, and into whether this affects the risk of maternal mortality.

Worldwide variations in the lifetime probability of reproductive cancer in women: implications of best-case, worst-case, and likely-case assumptions about the effect of oral contraceptive use.

Cancer incidence in countries representative of three patterns of reproductive cancer and age-specific mortality was used to estimate the effect of oral contraceptive use on the lifetime probability of reproductive cancer under three sets of assumptions about the effects of oral contraceptives. Under the set of assumptions considered likely, oral contraceptives were estimated to reduce or increase only slightly the lifetime probability of any reproductive cancer in each setting. Under worst-case assumptions, oral contraceptives were estimated to increase the lifetime probability of reproductive cancer only modestly in settings with low cancer rates and in settings with high rates of breast, ovarian, and endometrial cancer, but it might have a large impact on lifetime probability of reproductive cancer in settings with high cervical cancer rates. Under best-case assumptions, oral contraceptives were estimated to decrease the lifetime probability of reproductive cancer in each setting; this reduction was estimated to be greatest in settings where endometrial and ovarian cancer incidence are high.

PIP: Researchers applied published data on cancer incidence and age specific mortality to standard life table techniques to estimate the lifetime probability of developing reproductive cancer for women living in countries representative of 3 patters of risk of reproductive cancer and for long term oral contraceptives (OC) users under best case, worst case, and likely case assumptions. The reproductive cancers included breast, ovarian, endometrial, and cervical cancers. The data consisted of urban women from China, Japan, United States (California), England, Wales, Costa Rica, and Colombia. Under the likely case assumption, OCs just barely reduced or increased the lifetime probability of any reproductive cancer in any setting. Further, under the worst case scenario, OCs increased the lifetime probability or reproductive cancer moderately in countries with low cancer rates (Asian countries) and in countries with high rates of breast, ovarian, and endometrial cancer (Western Europe, North America, and Australia). Yet in countries with high cervical rates (South and Central America), OC use significantly affected the lifetime probability of reproductive cancer. The best case scenario revealed that OCs decreased lifetime probability of reproductive cancer in each country, especially those countries where endometrial and ovarian cancer incidences were great. The analysis also showed that OC use has the greatest effect on lifetime probability of reproductive cancer, be it positive or negative, in countries with high underlying rates of reproductive cancer. Further it demonstrated that the effect of OC use will most likely be small in countries with low incidence of reproductive cancers. Overall the researchers felt reassured about OC use and reproductive cancer. Even though long term OC use increases the risk of breast cancer in young ages.

Contribution to the study of the sinus node in aquatic mammals. A. Arterial blood of the sinus node in Minke whales / Contribuição ao estudo do nó sinoatrial em mamiferos aquáticos. A. vascularização arterial do nó sinoatrial em baleia Minke

It was studied the arterial blood supply of the sinus node in 20 Minke whales - 12 males and 8 females; the hearts were dissecated after fixation in formalin. It was observed that 15 times (75.0% ± 9.7) the nourishment of the node depends only of the ramus proximalis atrii dextri and 5 times (25.0% ± 9.7) it depends exclusively of the ramus proximalis atrii sinistri. They were registered 2 cases of arterial anastomosis between the implied vessels in the blood supply of the sinus node.

Estudou-se a vascularização arterial do nó sinoatrial em 20 corações de baleia Minke, 12 machos e 6 fêmeas, fixados em solução aquosa de formol a 151 e dissecados. Observou-se que a nutrição do nó sinoatrial, mais frequentemente - 15 vezes (75,0% ± 9,7), depende apenas do ramus proximalis atrii dextri e, nas restantes 5 vezes (25,0% ± 2,7), exclusivamente do ramus proximalis atrii sinistri. Registraram-se, 2 vezes, anastomoses arteriais entre vasos implicados na vascularização arterial do nó sinoatrial.

Contribution to the study of the sinus node in aquatic mammals. A. Arterial blood of the sinus node in Minke whales / Contribuição ao estudo do nó sinoatrial em mamiferos aquáticos. A. vascularização arterial do nó sinoatrial em baleia Minke

It was studied the arterial blood supply of the sinus node in 20 Minke whales - 12 males and 8 females; the hearts were dissecated after fixation in formalin. It was observed that 15 times (75.0% ± 9.7) the nourishment of the node depends only of the ramus proximalis atrii dextri and 5 times (25.0% ± 9.7) it depends exclusively of the ramus proximalis atrii sinistri. They were registered 2 cases of arterial anastomosis between the implied vessels in the blood supply of the sinus node.

Estudou-se a vascularização arterial do nó sinoatrial em 20 corações de baleia Minke, 12 machos e 6 fêmeas, fixados em solução aquosa de formol a 151 e dissecados. Observou-se que a nutrição do nó sinoatrial, mais frequentemente - 15 vezes (75,0% ± 9,7), depende apenas do ramus proximalis atrii dextri e, nas restantes 5 vezes (25,0% ± 2,7), exclusivamente do ramus proximalis atrii sinistri. Registraram-se, 2 vezes, anastomoses arteriais entre vasos implicados na vascularização arterial do nó sinoatrial.

Singapore in international comparisons of birthweight and perinatal mortality.

The position of Singapore as regards birthweight distribution and perinatal mortality has been compared with six countries in the 1973 WHO study namely, Austria, Cuba, Hungary, Japan, New Zealand and Sweden. Birthweight distribution and perinatal mortality reflect both the social and health conditions of a population and the standards of obstetric and paediatric care, and seeing where a country ranks in the international comparison of them may play a role in the formulation of health policy for that country. Singapore was well placed for the proportion of very low birthweight babies (less than 1,500 grams), ranking 2nd for both live births (0.5%) and total births (0.7%). It was however not so well placed for proportion of low birthweight babies (less than 2,500 grams), ranking 5th for both live births (8.8%) and total births (9.2%). With regard to perinatal mortality Singapore at 20.0 per 1,000 total births ranked 4th and this improved to 3rd after standardizing for birthweight and in fact was little different from Hungary (1st) and Sweden (2nd). Given that standardization for birthweight largely removes the effect of "socioeconomic and demographic factors" so that remaining differences to a large extent reflect medical care, this indicates a relatively high standard of perinatal care in Singapore. The problems of interpretation, the implications of the findings and suggestions for improving birth statistics in Singapore are discussed.

PIP: The situation in Singapore with regard to birthweight disbribution and perinatal mortality has been compared with 6 other countries in the 1973 WHO study. Those countries are: Austria, Cuba, Hungary, Japan, New Zealand, and Sweden. Birthweight distribution and perinatal mortality reflect both the social and health conditions of a population and the standards of obstetric and pediatric care. By evaluating where a country ranks in an international comparison, it is then possible for that country to formulate an appropriate health policy. Singapore ranked well in the proportion of very low birthweight babies (less than 1500 grams), ranked 2nd for livebirths (0.5%) and total births (0.7%), but did not rank as well in proportion of low birthweight babies (less than 2500 grams). Furthermore, Singapore ranked 5th for both live births (8.8%) and total births (9.2%). In the category of perinatal mortality, Singapore, with a rate of 20.0/1000 total births, ranked 4th and then moved into 3rd place after standardizing for birthweight. There was in fact little difference between Singapore and the 1st ranked (Hungary) and 2nd place (Sweden) countries. Given that standardization for birthweight removes for the most part the socioeconomic and demographic factors and leaves those factors reflecting medical care, this indicates a relatively high standard of perinatal care in Singapore. This article also examines problems of interpretation, the implications of the findings, and suggestions for improving birth statistics in Singapore.

Childhood mortality estimated from reports on previous births given by mothers at the time of a maternity: preceding-births technique.

PIP: This paper demostrates that, by using the Preceding-Births technique (Brass 1969), data can be collected to determine indices of the most recent childhood mortality using a totally different approach independent of the age of the mother reporting on the survivorship of previous children. This method is particularly simple since it requires only 1 question on the registration or notification form: is your last child still alive? No complex analysis and no dependence on other data sources or model life tables are necessary. An advantage of this method is the low % of selection bias. These techniques are concerned with the limited use of only that part of the maternity history data concerning mortality of recent births. Their use is recommended particularly for monitoring trends and evaluating intervention. In the interim before full registration exists in less developed countries, this is a valuable and viable means of estimating childhood mortality. Model tables describe distributions of intervals between live births reported from Colombia, Italy, USA, England and Wales; mortality schedules taken from African standards; and an estimation of proportion dead by the Preceding-Births technique in the Solomon Islands.^ieng

Lessons from the study of immigrant mortality.

PIP: This paper reports the results of a systematic review of mortality among immigrant groups in England and Wales. Mortality rates in 1970-72 were compared with rates both in the countries of origin and in England and Wales. All-cause male mortality was lower in immigrants from italy, the Caribbean, and Poland than in the countries of origin, suggesting a selection effect among migrants. The opposite patttern was noted for imigrants from Ireland, however, indicating social and health disadvantages may be a stimulus to migration. The high mortality from tuberculosis in immigrants from the indian subcontinent and Ireland, low mortality from ischemic heart disease and high mortality from cerebrovascular disease in Caribbean men, and low mortality from cancer of the lung and intestine in all but Irish men reflect the influence of the migrants' original country. A possible influence of the host country on determining disease rates is seen in adaptation of immigrant mortality ratios toward the England and Wales average. For example, immigrants from several countries analyzed had ischemic heart disease mortalty ratios intermediate between those for the original country and for England and Wales. In addition, British people born in the Indian subcontinent showed a mortality pattern intermediate between that of the Indians and the England and Wales average, supporting the argument that environmental rather than genetic determinants may be involved in the principal chronic diseases. Particularly high mortality from complications of pregnancy and childbirthwas noted in indian and Caribbean immigrants, indicating that there may be social and cultural barriers to the receipt of adequate medical care. Finally, social class differences did not account for mortality differences among immigrant groups. Mortality was higher for the Irish than the English or Welsh in each social class group, which suggests there are cultural influences on mortality that act independently of social class influences.^ieng

A reassessment of world population trends.

This reassessment is limited to observations concerning trends in mortality and fertility and concerning longrun prospects for population growth. Recorded changes in mortality are compared with 3 projections made many years ago. Projections of European mortality made in 1941-42 understated by a wide margin the actual increase in expectation of life because of unforeseen technological changes in the prevention and cure of fatal disease. On the other hand, a projection made in 1955 for India, foreseeing a rapid rise in the 1950s and slower progress later on because of the exhaustion of the easier gains, appears to have been accurate and also to depict the prospects in other populations of relatively high mortality and low income. A different projection of life expectancy in Mexico was also quite close to actual changes in Mexican mortality; it was based on a universal curve constructed to represent how life expectancy rises, increasing ever more slowly as it approaches an upper limit. This curve (1 for each sex), constructed for projection of Mexican mortality, is employed as a standard of comparison for mortality changes in many countries. A number have followed the standard for females very closely for more than 3 decades; in developed countries, male life expectancy has generally fallen short of the standard. The almost universal low fertility in developed countries contrasts with the great diversity of levels and trends of fertility in developing countries, some of which retain undiminished high fertility and others of which have recently attained rates of childbearing as low as in the developed areas. Instances of surprisingly little change and surprisingly rapid change in fertility are described. In the future, growth of populations of developed countries will probably be slight; the future rate of increase in the developing areas depends on the unpredictable timing and pace of childbearing reduction in populations where fertility remains high. In the long run, world population growth may resume its typical pattern of moderate growth interrupted by catastrophic setbacks.