Spatial distribution of Echinolitorina peruviana (Lamarck, 1882) for intertidal rocky shore in Antofagasta (23° S, Chile) / Distribuição espacial de Echinolitorina peruviana (Lamarck, 1882) para costa rochosa entremarés em Antofagasta (23 ° S, Chile)

Abstract The intertidal rocky shores in continental Chile have high species diversity mainly in northern Chile (18-27° S), and one of the most widespread species is the gastropod Echinolittorina peruviana (Lamarck, 1822). The aim of the present study is do a first characterization of spatial distribution of E. peruviana in along rocky shore in Antofagasta town in northern Chile. Individuals were counted in nine different sites that also were determined their spectral properties using remote sensing techniques (LANDSAT ETM+). The results revealed that sites without marked human intervention have more abundant in comparison to sites located in the town, also in all studied sites was found an aggregated pattern, and in six of these sites were found a negative binomial distribution. The low density related to sites with human intervention is supported when spectral properties for sites were included. These results would agree with other similar results for rocky shore in northern and southern Chile.

Resumo As costas rochosas entremarés no Chile continental apresentam alta diversidade de espécies, principalmente no norte do país (18-27 ° S), e uma das espécies mais difundidas é o gastrópode Echinolittorina peruviana (Lamarck, 1822). O objetivo do presente estudo é fazer uma primeira caracterização da distribuição espacial de E. peruviana no costão rochoso da cidade de Antofagasta no norte do Chile. Os indivíduos foram contados em nove locais diferentes onde também foram determinadas suas propriedades espectrais usando técnicas de sensoriamento remoto (LANDSAT ETM +). Os resultados revelaram que os locais sem intervenção humana marcada apresentam maior abundância em comparação aos locais localizados no município. Também em todos os locais estudados foi encontrado um padrão agregado, sendo que em seis desses locais foi encontrada uma distribuição binomial negativa. A baixa densidade relacionada a sites com intervenção humana é suportada quando as propriedades espectrais para sites foram incluídas. Esses resultados concordariam com outros resultados semelhantes para costões rochosos no norte e no sul do Chile.

Spatial distribution of Echinolitorina peruviana (Lamarck, 1882) for intertidal rocky shore in Antofagasta (23° S, Chile) / Distribuição espacial de Echinolitorina peruviana (Lamarck, 1882) para costa rochosa entremarés em Antofagasta (23 ° S, Chile)

The intertidal rocky shores in continental Chile have high species diversity mainly in northern Chile (18-27° S), and one of the most widespread species is the gastropod Echinolittorina peruviana (Lamarck, 1822). The aim of the present study is do a first characterization of spatial distribution of E. peruviana in along rocky shore in Antofagasta town in northern Chile. Individuals were counted in nine different sites that also were determined their spectral properties using remote sensing techniques (LANDSAT ETM+). The results revealed that sites without marked human intervention have more abundant in comparison to sites located in the town, also in all studied sites was found an aggregated pattern, and in six of these sites were found a negative binomial distribution. The low density related to sites with human intervention is supported when spectral properties for sites were included. These results would agree with other similar results for rocky shore in northern and southern Chile.

As costas rochosas entremarés no Chile continental apresentam alta diversidade de espécies, principalmente no norte do país (18-27 ° S), e uma das espécies mais difundidas é o gastrópode Echinolittorina peruviana (Lamarck, 1822). O objetivo do presente estudo é fazer uma primeira caracterização da distribuição espacial de E. peruviana no costão rochoso da cidade de Antofagasta no norte do Chile. Os indivíduos foram contados em nove locais diferentes onde também foram determinadas suas propriedades espectrais usando técnicas de sensoriamento remoto (LANDSAT ETM +). Os resultados revelaram que os locais sem intervenção humana marcada apresentam maior abundância em comparação aos locais localizados no município. Também em todos os locais estudados foi encontrado um padrão agregado, sendo que em seis desses locais foi encontrada uma distribuição binomial negativa. A baixa densidade relacionada a sites com intervenção humana é suportada quando as propriedades espectrais para sites foram incluídas. Esses resultados concordariam com outros resultados semelhantes para costões rochosos no norte e no sul do Chile.

Spatial distribution of Echinolitorina peruviana (Lamarck, 1882) for intertidal rocky shore in Antofagasta (23° S, Chile)

Abstract The intertidal rocky shores in continental Chile have high species diversity mainly in northern Chile (18-27° S), and one of the most widespread species is the gastropod Echinolittorina peruviana (Lamarck, 1822). The aim of the present study is do a first characterization of spatial distribution of E. peruviana in along rocky shore in Antofagasta town in northern Chile. Individuals were counted in nine different sites that also were determined their spectral properties using remote sensing techniques (LANDSAT ETM+). The results revealed that sites without marked human intervention have more abundant in comparison to sites located in the town, also in all studied sites was found an aggregated pattern, and in six of these sites were found a negative binomial distribution. The low density related to sites with human intervention is supported when spectral properties for sites were included. These results would agree with other similar results for rocky shore in northern and southern Chile.

Resumo As costas rochosas entremarés no Chile continental apresentam alta diversidade de espécies, principalmente no norte do país (18-27 ° S), e uma das espécies mais difundidas é o gastrópode Echinolittorina peruviana (Lamarck, 1822). O objetivo do presente estudo é fazer uma primeira caracterização da distribuição espacial de E. peruviana no costão rochoso da cidade de Antofagasta no norte do Chile. Os indivíduos foram contados em nove locais diferentes onde também foram determinadas suas propriedades espectrais usando técnicas de sensoriamento remoto (LANDSAT ETM +). Os resultados revelaram que os locais sem intervenção humana marcada apresentam maior abundância em comparação aos locais localizados no município. Também em todos os locais estudados foi encontrado um padrão agregado, sendo que em seis desses locais foi encontrada uma distribuição binomial negativa. A baixa densidade relacionada a sites com intervenção humana é suportada quando as propriedades espectrais para sites foram incluídas. Esses resultados concordariam com outros resultados semelhantes para costões rochosos no norte e no sul do Chile.

Calculation of the Probability Distribution of CIBS Score in Different Relationships and Its Application / 法医学杂志

Objective To derive the probability distribution formula of combined identity by state （CIBS） score among individuals with different relationships based on population data of autosomal multiallelic genetic markers. Methods The probabilities of different identity by state （IBS） scores occurring at a single locus between two individuals with different relationships were derived based on the principle of ITO method. Then the distribution probability formula of CIBS score between two individuals with different relationships when a certain number of genetic markers were used for relationship identification was derived based on the multinomial distribution theory. The formula was compared with the CIBS probability distribution formula based on binomial distribution theory. Results Between individuals with a certain relationship, labelled as RS, the probabilities of IBS=2, 1 and 0 occurring at a certain autosomal genetic marker x （that is, p2（RSx）, p1（RSx） and p0（RSx））, can be calculated based on the allele frequency data of that genetic marker and the probability of two individuals with the corresponding RS relationship sharing 0, 1 or 2 identity by descent （IBD） alleles （that is, φ0, φ1 and φ2）. For a genotyping system with multiple independent genetic markers, the distribution of CIBS score between pairs of individuals with relationships other than parent-child can be deducted using the averages of the 3 probabilities of all genetic markers （that is, p2（RS）, p1（RS） and p0（RS））, based on multinomial distribution theory. Conclusion The calculation of CIBS score distribution formula can be extended to all kinships and has great application value in case interpretation and system effectiveness evaluation. In most situations, the results based on binomial distribution formula are similar to those based on the formula derived in this study, thus, there is little difference between the two methods in actual work.

Symptoms of schizophrenia and regularity in treatment: a stochastic analysis

Background: The alarming rise of mental disorders worldwide stimulates the need to study them from a statistical viewpoint. Schizophrenia is one of the most prevalent mental illness which is characterised by various symptoms, the presence of a cluster of which leads to its diagnosis. Regular treatment leads to a remission of the illness which might relapse on discontinuity of medicines. There have been numerous epidemiological studies and clinical trials on the illness. However, schizophrenia also poses a challenge to statisticians in theorising and statistically modeling its different aspects. Aim: This is an attempt to study, by developing suitable stochastic models, the behaviour of the symptoms of schizophrenia manifested in a patient in relation to the successive visits to the doctor. Methods: The concepts of probability theory, structure functions, binomial distribution, Markov chain, and transition probabilities are the statistical tools used to model the medical facts regarding schizophrenia. Results: By developing probabilistic and stochastic models, a relationship between the number of symptoms at the time of diagnosis and the number of revisits to the doctor has been developed and thereby an important result regarding the expected number of symptoms present at a particular visit to the doctor has been established. A Markovian model studying the pattern of the symptoms in the course to recovery has been presented and its application in the behaviour of the symptoms of schizophrenia has been verified. Conclusions: It is expected that the above results might help doctors in planning out the treatment schedule in advance. It can also lead to a further study on cost benefit analysis of the treatment process.

Spatial distribution in marine invertebrates in rocky shore of Araucania Region (38° S, Chile) / Distribuição espacial em invertebrados marinhos na costa rochosa da região de Araucanía (38° S, Chile)

Abstract The rocky shores in Chile have a wide invertebrate species diversity, that include species with marked abundances in determined regions. The aim of the present study is to analyse the spatial distribution pattern in different marine invertebrate species in rocky shore of Araucania region, considering if these species have random, uniform or associated patterns, and extrapolate if these patterns have Poisson, binomial or negative binomial distribution respectively. The results revealed the presence mainly of gastropods molluscs that would graze on benthic algae, these species have mainly aggregated pattern that has a robust negative binomial distribution pattern. The obtained results agree with observations for marine benthic fauna that mentioned the presence of aggregated pattern, has negative binomial distribution. Other ecological topics about spatial distribution were discussed.

Resumo As costas rochosas no Chile têm uma ampla diversidade de espécies de invertebrados, que incluem espécies com abundância marcada em determinadas regiões. O objetivo do presente estudo é analisar o padrão de distribuição espacial em diferentes espécies de invertebrados marinhos na costa rochosa da região de Araucanía, considerando se essas espécies possuem padrões aleatórios, uniformes ou associados, e extrapolar se esses padrões possuem distribuição binomial de Poisson, binomial ou negativa. respectivamente. Os resultados revelaram a presença principalmente de moluscos gastrópodes que pastam em algas bentônicas, estas espécies têm principalmente agregado padrão que tem um padrão robusto de distribuição binomial negativa, padrão agregado de grupos, e a fauna de água doce que apresenta distribuição binomial negativa. Outros tópicos ecológicos sobre distribuição espacial foram discutidos.

Investigation and Analysis of Familial Aggregation of Helicobacter pylori Infection / 胃肠病学

Background: Helicobacter pylori (Hp) infection is an important public health problem, and the transmission mode of Hp is not yet fully understood, however, human-to-human transmission route has been widely recognized, thus familial aggregation may occur for Hp infection. Aims: To explore the Hp infection in family members of Hp-positive patients and to analyze the familial aggregation of Hp infection. Methods: A total of 976 patients who underwent 14C-urea breath test (14C-UBT) from January 2018 to January 2019 were enrolled. According to Hp infection, the subjects were divided into Hp-positive group (case group) and Hp-negative group (control group), and all family members of all the subjects were encouraged to detect Hp infection. The Hp infection of family members in the two groups, the consistence of Hp infection between husband and wife, and the relationship between Hp-positive parents and Hp infection of children in case group were analyzed, and the goodness-of-fit test for binomial distribution was used to explore familial aggregation of Hp infection. Results: Among the 493 complete families who completed the survey, Hp-positivity rate in parents, spouses, children in case group were 70.6%, 62.1%, 65.9%, respectively, and were significantly higher than those in parents, spouses, children in control group (63.2%, 54.4%, 56.7%, respectively) (P0.05). Among 548 children in case group, 361 children were Hp positive, and the infection rate was increased with the increase of parental infection (P<0.05). The goodness-of-fit test showed that there were statistically significant differences in the actual households distribution and theoretical households distribution of Hp infection (P<0.05). Conclusions: There is a certain familial aggregation of Hp infection. When a member of the family is infected, the risk of Hp infection of parents, spouses and children may increase.

Equation Derivation of the Probability Distribution of IBS Score among Full Sibling Pairs / 法医学杂志

Objective To derive the general equation of the probability distribution of identity by state （IBS） score among biological full sibling pairs by calculating STR allele frequency. Methods Based on the Mendelian genetics law and the hypothesis that parents of biological full siblings （FS） were unrelated individuals, the IBS score and corresponding probability of different genotype combinations in the offspring when unrelated individuals of different genotype combinations give birth to two offsprings were derived. Results Given fi （i=1, 2, …, m） as the frequency of the ith allele of a STR locus, the probability of sharing 2 alleles （p2FS）, 1 allele （p1FS） or 0 allele （p0FS） with biological full sibling pairs on the locus can be respectively expressed as follows： (see the text). The sum of p2FS, p1FS and p0FS must be 1. As for the multiple genotyping system that contained n STR loci, IBS scores between biological full sibling pairs conform to binomial distribution： IBS~B（2n, π1）. The population rate π1, can be given by the formula： (see the text). Conclusion The alternative hypothesis in biological full sibling testing is that two appraised individuals are biological full siblings. The probability of the corresponding alternative hypothesis of any STR locus combination or IBS score can be directly calculated by the equations presented in this study, and the calculation results are the basis for explanations of the evidence.

Formula Derivation for the Probability Distribution of IBS Score in Unrelated Individual Pairs / 法医学杂志

@#Objective To derive the general equation of the probability distribution of identity by state （IBS） score among biological full sibling pairs by calculating STR allele frequency. Methods Based on the Mendelian genetics law and the hypothesis that parents of biological full siblings（FS） were unrelated individuals, the IBS score and corresponding probability of different genotype combinations in the offspring when unrelated individuals of different genotype combinations give birth to two offsprings were derived. Results Given fi （i=1, 2, …, m） as the frequency of the ith allele of a STR locus, the probability of sharing 2 alleles（p2FS）, 1 allele（p1FS） or 0 allele （p0FS） with biological full sibling pairs on the locus can be respectively expressed as follows： p2FS= 14 ×[1 + 2∑im= 1 fi2 + 2（∑im= 1 fi2）2 -∑im= 1 fi4] , p1FS= 12 ×[1 +∑im= 1 fi2 - 2（∑im= 1 fi2）2 - 2∑im= 1 fi3 + 2∑im= 1 fi4] and p0FS= 14 ×[1 - 4∑im= 1 fi2 + 2（∑im= 1 fi2）2 + 4∑im= 1 fi3 -3∑im= 1 fi4] . The sum of p2FS, p1FS and p0FS must be 1. As for the multiple genotyping system that contained n STR loci, IBS scores between biological full sibling pairs conform to binomial distribution：IBS~B（2n, π1）. The population rate π1, can be given by the formula：π1= 1n∑ln= 1 p2FSl + 21n∑ln= 1 p1FSl . Conclusion The alternative hypothesis in biological full sibling testing is that two appraised individuals are biological full siblings. The probability of the corresponding alternative hypothesis of any STR locus combination or IBS score can be directly calculated by the equations presented in this study, and the calculation results are the basis for explanations of the evidence.

Social determinants of tuberculosis via a zero-inflated model in small areas of a city in Southeastern Brazil

Abstract INTRODUCTION: This study aimed to analyze social factors involved in the spatial distribution and under-reporting of tuberculosis (TB) in the city of Vitória, Espírito Santo State, Brazil. METHODS: This was an ecological study of the reported cases of TB between 2009 and 2011, according to census tracts. The outcome was TB incidence for the study period and the variables of exposure were proportions of literacy, inhabitants with an income of up to half the minimum monthly wage (MMW), and inhabitants associated with sewer mains or with access to safe drinking water. We used a zero-inflated process, zero-inflated negative binomial regression (ZINB), and selected an explanatory model based on the Akaike Information Criterion (AIC). RESULTS: A total of 588 cases of tuberculosis were reported in Vitória during the study period, distributed among 223 census tracts (38.6%), with 354 (61.4%) tracts presenting zero cases. In the ZINB model, the mean value of p i was 0.93, indicating that there is a 93% chance that an observed false zero could be due to sub-notification. CONCLUSIONS: It is important to prioritize areas exhibiting determinants that influence the occurrence of TB in the municipality of Vitória. The zero-inflated model can be useful to the public health sector since it identifies the percentage of false zeros, generating an estimate of the real epidemiological condition of TB in Vitória.

Formula Derivation for the Probability Distribution of IBS Score in Unrelated Individual Pairs / 法医学杂志

OBJECTIVES@#To derive the probability equation given by STR allele frequencies of identity by state （IBS） score shared by unrelated individual pairs.@*METHODS@#By comparing the STR genotypes of two unrelated individuals, three mutually exclusive combinations could be obtained： （1） sharing 2 identical alleles, a₂=1, otherwise a₂=0; （2） sharing 1 identical allele, a₁=1, otherwise a₁=0; （3） sharing 0 identical allele, a₀=1, otherwise a₀=0. And the IBS score of the one STR locus in this unrelated individual pair could be given by the formula： ibs=2a₂+a₁. The probability of a₂=1 （p₂）, a₁=1 （p₁） and a₀=1 （p₀） were derived and expressed in powers of the allele frequencies. Subsequently, for a genotyping system including n independent STR loci, the characteristics of binomial distribution of IBS score shared by a pair of unrelated individuals could be given by p₂l and p₁l （l=1, 2, …, n）.@*RESULTS@#All the general equations of p₂, p₁ and p₀ were derived from the basic conceptions of a₂, a₁ and a₀, respectively. Given fi （i=1, 2, …, m） as the ith allele frequency of a STR locus, the general equations of p₂, p₁ and p₀ could be respectively expressed in powers of fi： [Formula: see text],[Formula: see text] and [Formula: see text]. The sum of p₂, p₁ and p₀ must be equal to 1. Then, the binomial distribution of IBS score shared by unrelated individual pairs genotyped with n independently STR loci could be written by： IBS~B（2n, π）, and the general probability, π, could be given by the formula： [Formula: see text].@*CONCLUSIONS@#In the biological full sibling identification, the probability of null hypothesis corresponding to any specific IBS score can be directly calculated by the general equations presented in this study, which is the basement of the evidence explanation.

Spatial distribution in marine invertebrates in rocky shore of Araucania Region (38° S, Chile)

Abstract The rocky shores in Chile have a wide invertebrate species diversity, that include species with marked abundances in determined regions. The aim of the present study is to analyse the spatial distribution pattern in different marine invertebrate species in rocky shore of Araucania region, considering if these species have random, uniform or associated patterns, and extrapolate if these patterns have Poisson, binomial or negative binomial distribution respectively. The results revealed the presence mainly of gastropods molluscs that would graze on benthic algae, these species have mainly aggregated pattern that has a robust negative binomial distribution pattern. The obtained results agree with observations for marine benthic fauna that mentioned the presence of aggregated pattern, has negative binomial distribution. Other ecological topics about spatial distribution were discussed.

Resumo As costas rochosas no Chile têm uma ampla diversidade de espécies de invertebrados, que incluem espécies com abundância marcada em determinadas regiões. O objetivo do presente estudo é analisar o padrão de distribuição espacial em diferentes espécies de invertebrados marinhos na costa rochosa da região de Araucanía, considerando se essas espécies possuem padrões aleatórios, uniformes ou associados, e extrapolar se esses padrões possuem distribuição binomial de Poisson, binomial ou negativa. respectivamente. Os resultados revelaram a presença principalmente de moluscos gastrópodes que pastam em algas bentônicas, estas espécies têm principalmente agregado padrão que tem um padrão robusto de distribuição binomial negativa, padrão agregado de grupos, e a fauna de água doce que apresenta distribuição binomial negativa. Outros tópicos ecológicos sobre distribuição espacial foram discutidos.

Mortalidade por câncer do colo do útero no estado do Rio Grande do Norte, no período de 1996 a 2010: tendência temporal e projeções até 2030 / Cervical cancer mortality in the state of Rio Grande do Norte, Brazil, 1996-2010: time trends and projections up to 2030 / Mortalidad por cáncer de cuello de útero en el estado de Rio Grande del Norte, en el período de 1996 a 2010: tendencia temporal y proyecciones hasta el año 2030

OBJETIVO: analisar a tendência da mortalidade por câncer do colo do útero no estado do Rio Grande do Norte e em suas microrregiões de saúde, no período de 1996 a 2010, e realizar projeções para os quinquênios, de 2011 a 2030. MÉTODOS: estudo ecológico de series temporais; empregou-se regressão binomial negativa para análise das tendências e projeções. RESULTADOS: foram observadas taxas acima de 5,0 óbitos por 100 mil mulheres em todas as microrregiões, com tendência estacionária para o estado e ascendente nas microrregiões com piores condições socioeconômicas; as projeções indicaram redução nas taxas de mortalidade no estado, de 5,95/100 mil mulheres (2006-2010) para 3,67 (2026-2030), embora seja previsto aumento de 22% no número absoluto de óbitos. CONCLUSÃO: apesar da previsão de redução nas taxas de mortalidade, estas ainda apresentam-se elevadas, sinalizando a necessidade de revisão e fortalecimento do programa de controle do câncer do colo do útero no estado.

OBJECTIVE: to analyze cervical cancer mortality trends in the state of Rio Grande do Norte and its health micro-regions from 1996 to 2010, as well as to make projections for five-year periods from 2011 to 2030. METHODS: this was an ecological time series study; negative binomial regression was used to analyze trends and projections. RESULTS: rates above 5.0 deaths per 100,000 women were observed in all the micro-regions, with a stationary trend in the state as a whole and an upward trend in the micro-regions with the worst socioeconomic conditions; projections indicated reduction in mortality rates in the state, from 5.95/100,000 women (2006-2010) to 3.67 (2026-2030), although a 22% increase in the absolute number of deaths is expected. CONCLUSION: although a reduction in mortality rates is projected, they continue to be high, indicating the need for review and strengthening of the state's cervical cancer control program.

OBJETIVO: analizar la tendencia de mortalidad por cáncer de cuello de útero en el estado de Rio Grande del Norte (RN) y en sus microrregiones de salud, en el período de 1996 a 2010, así como realizar proyecciones para los períodos quinquenales entre 2011 y 2030. MÉTODOS: estudio ecológico de series de tiempo; se utilizó regresión binomial negativa para analizar tendencias y proyecciones. RESULTADOS: observamos tasas de 5.0 muertes por cada 100 mil mujeres en todas las microrregiones, con una tendencia estacionaria para el estado y ascendente en las microrregiones con peores condiciones socioeconómicas. Las proyecciones mostraron una reducción en las tasas de mortalidad en el estado, de 5.95/100 mil mujeres (2006-2010) para 3.67 (2026-2030), aunque se espere un aumento de 22% en el número absoluto de muertes. CONCLUSIÓN: a pesar del pronóstico de reducción de las tasas de mortalidad, estas siguen siendo altas, lo que indica la necesidad de revisar y fortalecer el programa de control de cáncer de cuello uterino en el estado.

Use of a negative binomial distribution to describe the presence of Sphyrion laevigatum in Genypterus blacodes / Uso de distribuição binomial negativa para descrever a presença de Sphyrion laevigatum em Genypterus blacodes

This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.

Este artigo descreve a frequência e o número de Sphyrion laevigatum da pele de Genypterus blacodes, o qual é um importante recurso econômico no Chile. A análise baseada em modelos de distribuição espacial, demonstrou que os parasitos tendem a ficar agrupados. A variação numérica de parasitas por hospedeiro pode ser descrita por distribuição binomial negativa. O número máximo observado de parasitas por hospedeiro foi dois.

The Sudden Infant Death Syndrome is a Probability Process.

The Sudden Infant Death Syndrome (SIDS) is sudden-unexpected death of an infant that remains unexplained after thorough forensic autopsy, death scene investigation and review of the infant's medical history. As the results of a few spins of a roulette wheel cannot establish whether the wheel is honest (uniform value distribution), medical investigations of a few SIDS cases have not been able to uncover the mechanistic cause of death. We propose that this is because statistical analyses of large numbers of independent observations may be required to unmask the apparent probability processes that govern these quite different phenomena. The SIDS male fraction ~0.60 appears as a binomial probability sample characteristic of a condition caused by an Xlinked gene. The unique SIDS age distribution (minimum at birth, mode ~63 days, median ~94 days, falling exponentially to zero at ~41.2 months) appears as a probability sample from an underlying Johnson SB (4-parameter lognormal) distribution of ages. The presence of this lognormal distribution is prima facie evidence that a probability process is involved. Matching binomial and SB distribution equations to these physiological phenomena, we propose: The SIDS binomial gender distributions arises from an Xlinked recessive allele (q ≈ 2/3) non-protective against acute anoxic encephalopathy; and SIDS Johnson SB age distributions arise from such genetically susceptible infants having three independent risk factors: neurological prematurity (m + 0.31)-1 decreasing with age in months m; risk of respiratory infection increasing with age (41.2 - m)-1; and risk of physiological anemia rising and falling with age (2ᴨσ2)-1/2[exp(-0.5[(y-μ)/σ]2)] , where y = Log[(m + 0.31)/(41.2 - m)] = μ + σ z, μ is median of y, σ is standard deviation of y, with z a standard normal deviate. We show infant Respiratory Distress Syndrome and Suffocation by Inhalation of Food or Foreign Object have approximately the same male fractions as SIDS, supporting the hypothesis that the same allele of an X-linked gene is responsible for death in all these cases.

Study of space distribution law of death cases of hemorrhagic fever with renal syndrome in Kaijiang county,Dazhou city, Sichuan province / 中国地方病学杂志

Objective To study the space distribution probability model of death cases of hemorrhagic fever with renal syndrome,so as to provide basic information for hemorrhagic fever with renal syndrome prevention and control policy making.Methods Poisson distribution and negative binomial distribution were used to fit the hemorrhagic fever with renal syndrome deaths spatial distribution in Kaijiang county,Dazhou city,Sichuan province between 1979-2010.Results The actual distribution of death cases of hemorrhagic fever with renal syndrome in Kaijiang county was not Poisson distribution (x2 =40.64,P ＜ 0.01),but subjected to the negative binomial distribution(x2 =1.86,P ＞ 0.50).Conclusions The space distribution of death cases of HFRS in Kaijiang county is not random,but has strict regional aggregation,which may be related to the local medical conditions,patient' s lack of knowledge about health care and other factors.

Use of negative binomial distribution to describe the presence of Anisakis in Thyrsites atun / Uso de distribuição binomial negativa para descrever a presença de Anisakis em Thyrsites atun

Nematodes of the genus Anisakis have marine fishes as intermediate hosts. One of these hosts is Thyrsites atun, an important fishery resource in Chile between 38 and 41° S. This paper describes the frequency and number of Anisakis nematodes in the internal organs of Thyrsites atun. An analysis based on spatial distribution models showed that the parasites tend to be clustered. The variation in the number of parasites per host could be described by the negative binomial distribution. The maximum observed number of parasites was nine parasites per host. The environmental and zoonotic aspects of the study are also discussed.

Nematóides do gênero Anisakis têm nos peixes marinhos seus hospedeiros intermediários. Um desses hospedeiros é Thyrsites atun, um importante recurso pesqueiro no Chile entre 38 e 41° S. Este artigo descreve a freqüência e o número de nematóides Anisakis nos órgãos internos de Thyrsites atun. Uma análise baseada em modelos de distribuição espacial demonstrou que os parasitos tendem a ficar agrupados. A variação numérica de parasitas por hospedeiro pôde ser descrita por distribuição binomial negativa. O número máximo observado de parasitas por hospedeiro foi nove. Os aspectos ambientais e zoonóticos desse estudo também serão discutidos.

Pooled sampling method under given sensitivity and specificity in improving accuracy of point estimator of population rate / 第二军医大学学报

Objective: To use the pooled sampling method to reduce the error caused by the detecting precision, so as to improve the accuracy of population rate estimates. Methods: A formula was deduced on how to obtain the ideal rate under given sensitivity and specificity, and the mean relative errors of rate estimation with different pool sizes were simulated and calculated using software SAS 9.1. Results: When the actual rate was lower than the ideal rate, the errors caused by the detecting precision could be greatly reduced through adjusting the rate of mixed samples. Conclusion: When the population rate is low, the accuracy of rate estimation can be improved and the numbers of tests can be reduced by using pooled sampling method under given specificity and sensitivity.

Distribuição espacial de Tenuipalpus heveae Baker (Acari: Tenuipalpidae) na cultura da seringueira / Spatial distribution of Tenuipalpus heveae Baker (Acari: Tenuipalpidae) on rubber tree plantations

The objective of this work was to study the spatial distribution of Tenuipalpus heveae Baker in rubber tree plantations. The experimental area was located in Marinópolis, State of São Paulo, and corresponded to a total of 1,000 plants (clone RRIM 600) divided in 100 plots of ten plants each. A total of 16 samplings were conducted, approximately once every 10 days, between December 2007 and June 2008. On each date, samples were taken from two plants per plot, each sample corresponding to the top 30 cm of a branch randomly taken from the median region of the canopy of each plant. The number of T. heveae was evaluated on three leaflets randomly taken from each sample, using a 20x power pocket magnifying glass. The number of mites was evaluated in two areas of 1 cm² delimited on the lower surface of each leaflet, being one along the midrib and the other along a lateral vein. The calculated dispersion indexes were: variance/mean relationship (I), index of Morisita (I´), coefficient of Green (Cx) and k exponent of negative binomial distribution. Tenuipalpus heveae showed aggregate distribution. The negative binomial distribution model was the most appropriate to represent the spatial distribution of the mite in the rubber tree plantation.

Study on risk factors of gastric cancer in Wuwei city of Gansu province / 肿瘤研究与临床

Objective The incidence of gastric carcinoma(GC) has significantly difference in different areas because it has different cancerogenic and stimulative factors in different areas. Through displaying the epidemic factors of popular GC in Wuwei city, it can supply etiological clue of the first-level prevention to GC. Methods The research methods about epidemiology of migrant were used to investigate the case fatality rate of GC about the people in Qitai county of Xinjiang province who immigrated from Wuwei. According to the information of GC-death registered, we fitted local cluster analyse with Possion-distribution model, and then the results were processed with case-control study of chi square test; Binomial distribution (p+q)n model was used to familial cluster analysis, and the statistical method of X2 was used to compare the difference between the actual incidence and theoretical incidence of GC. Adopting the history arrangement analysis, the canceration of four precancerous diseases were observed. Nitrogen content of nitrate and nitrite in drinking water were respectively measured by using ultraviolet spectrophotometric and hydrochloride naphthaline ethylenediamine methods. Results The death rates of GC of the first-generation and their descendants of emigrants were much lower than those contemporary beings in Wuwei, but were higher than those contemporary beings in Qitai country. The prevalence of GC had region and familial aggregation. The year canceration proportion of people who had precancerous diseases such as stomach polypus, atrophyic gastritis,gastric ulcer, and remnant stomach were 0.459 %, 0.431%, 0.381% and 0.178 % respectively. The percentage of crowd attributive risk were 41.26 %, 29.35 %, 4.68 % and 3.39 % respectively. Nitrogen contents of nitrate and nitrite either in surface water or in shallow water were significantly higher in Wuwei city than that in Lanzhou city (P＜0.01). Conclusion Death rates of GC for the emigrants of the first-generation and their descendants are much lower than their ancestry, but higher than those of the generation in Qitai county. The prevalence of GC has region and familial aggregation. It is the immanent factor of popular GC in Wuwei City that there are higher contents of nitrogen content of nitrate and nitrite in residenter' s drinking water and four precancerous diseases including stomach polypus, atrophyic gastritis, gastric ulcer,and remnant stomach.