47 research outputs found
Resultados perinatais em gestações tardias
O objetivo do estudo foi comparar resultados perinatais de mulheres com idade igual ou superior a 35 anos com os de mulheres entre 20 e 34 anos. O estudo é retrospectivo e foi realizado a partir da consulta às fichas obstétricas de 1.255 puérperas que tiveram partos no único hospital de Sarandi-PR, no período de janeiro de 2007 a dezembro de 2008. As variáveis analisadas foram: estado civil, escolaridade, idade gestacional, tipo de parto, peso ao nascer, índice de Apgar no 1º e 5º minutos e óbitos fetais. Na regressão logística, a idade materna avançada esteve associada significativamente à cesariana (OR 1,23, IC 95% 0,19-0,44) e a um índice de Apgar menor que 7 no 5º minuto de vida (OR 5,78, IC 95% 0,74-2,76). Esses resultados evidenciam os riscos de complicações em gestantes com idade igual ou superior a 35 anos e a necessidade de que o aconselhamento às mulheres que pretendam postergar a gestação seja realizado
A high quality assembly of the Nile Tilapia (Oreochromis niloticus) genome reveals the structure of two sex determination regions
Background Tilapias are the second most farmed fishes in the world and a sustainable source of food. Like many other fish, tilapias are sexually dimorphic and sex is a commercially important trait in these fish. In this study, we developed a significantly improved assembly of the tilapia genome using the latest genome sequencing methods and show how it improves the characterization of two sex determination regions in two tilapia species. Results A homozygous clonal XX female Nile tilapia (Oreochromis niloticus) was sequenced to 44X coverage using Pacific Biosciences (PacBio) SMRT sequencing. Dozens of candidate de novo assemblies were generated and an optimal assembly (contig NG50 of 3.3Mbp) was selected using principal component analysis of likelihood scores calculated from several paired-end sequencing libraries. Comparison of the new assembly to the previous O. niloticus genome assembly reveals that recently duplicated portions of the genome are now well represented. The overall number of genes in the new assembly increased by 27.3%, including a 67% increase in pseudogenes. The new tilapia genome assembly correctly represents two recentvasagene duplication events that have been verified with BAC sequencing. At total of 146Mbp of additional transposable element sequence are now assembled, a large proportion of which are recent insertions. Large centromeric satellite repeats are assembled and annotated in cichlid fish for the first time. Finally, the new assembly identifies the long-range structure of both a ~9Mbp XY sex determination region on LG1 in O. niloticus, and a ~50Mbp WZ sex determination region on LG3 in the related species O. aureus. Conclusions This study highlights the use of long read sequencing to correctly assemble recent duplications and to characterize repeat-filled regions of the genome. The study serves as an example of the need for high quality genome assemblies and provides a framework for identifying sex determining genes in tilapia and related fish species
Influence of handaxe size and shape on cutting efficiency: a large-scale experiment and morphometric analysis
Handaxes represent one of the most temporally enduring and geographically widespread of Palaeolithic artifacts and thus comprised a key technological strategy of many hominin populations. Archaeologically observable variation in the size (i.e., mass) and shape properties of handaxes has been frequently noted. It is logical to ask whether some of this variability may have had functional implications. Here, we report the results of a large-scale (n = 500 handaxes) experiment designed to examine the influence of variation in handaxe size and shape on cutting efficiency rates during a laboratory task. We used a comprehensive dataset of morphometric (size-adjusted) shape variables and statistical methods (including multivariate methods) to address this issue. Our first set of analyses focused on handaxe mass/size variability. This analysis demonstrated that, at a broad-scale level of variation, handaxe mass may have been free to vary independently of functional (cutting) efficiency. Our analysis also, however, identified that there will be a task-specific threshold in terms of functional effectiveness at the lower end of handaxe mass variation. This implies that hominins may have targeted design forms to meet minimal (task-specific) thresholds, and may also have managed handaxe reduction and discard in respect to such factors. Our second set of analyses focused on handaxe shape variability. This analysis also indicated that considerable variation in handaxe shape may occur independently of any strong effect on cutting efficiency. We discuss how these results have several implications for considerations of handaxe variation in the archaeological record. At a general level, our results demonstrate that variability within and between handaxe assemblages in terms of their size and shape properties will not necessarily have had immediate or strong impact on their effectiveness when used for cutting, and that such variability may have been related to factors other than functional issues