Selection and validation of reference genes by RT-qPCR under photoperiodic induction of flowering in sugarcane (Saccharum spp.).

Although reference genes have previously been used in the expression analysis of genes involved in sugarcane flowering they had not been experimentally validated for stability and consistency of expression between different samples over a wide range of experimental conditions. Here we report the analysis of candidate reference genes in different tissue types, at different temporal time-points, in both short and long day photoperiodic treatments. The stability of the candidate reference genes in all conditions was evaluated with NormFinder, BestKeeper, and RefFinder algorithms that complement each other for a more robust analysis. As the Normfinder algorithm was more appropriate for our experimental conditions, greater emphasis was placed on Normfinder when choosing the most stable genes. UBQ1 and TUB were shown to be the most stable reference genes to use for normalizing RT-qPCR gene expression data during floral induction, whilst 25SrRNA1 and GAPDH were the least stable. Their use as a reference gene pair was validated by analyzing the expression of two differentially expressed target genes (PIL5 and LHP1). The UBQ1/TUB reference genes combination was able to reveal small significant differences in gene expression of the two target genes that were not detectable when using the least stable reference gene combination. These results can be used to inform the choice of reference genes to use in the study of the sugarcane floral induction pathway. Our work also demonstrates that both PIL5 and LHP1 are significantly up-regulated in the initial stages of photoperiodic induction of flowering in sugarcane.

Corrigendum: Revisiting Meiosis in Sugarcane: Chromosomal Irregularities and the Prevalence of Bivalent Configurations.

[This corrects the article DOI: 10.3389/fgene.2018.00213.].

A predictive model for fall risk in hospitalized adults: A case-control study.

AIM: To develop and validate a predictive model for falls in hospitalized adult clinical and surgical patients, assessing intrinsic (i.e. patient-related) and extrinsic factors (i.e. care process-related). BACKGROUND: To identify factors predictive of falls and enable appropriate management of fall risk it is necessary to understand patient and environmental factors, along with care delivery processes. DESIGN: A matched case-control study. METHODS: This study was conducted in the medical and surgical wards of a Brazilian teaching hospital. The sample included 536 patients, with data collected in 2013-2014. Data analysis included descriptive statistics and conditional logistic regression. Cases of patients aged 18 years or older who fell while hospitalized were included. One patient who did not fall during hospitalization, matched by sex, ward and admission date, was selected as a control for each included case. RESULTS: The SAK Fall Scale (Severo-Almeida-Kuchenbecker) was developed and validated. The scale includes seven variables: disorientation/confusion, frequent urination, walking limitations, lack of caregiver, postoperative status, previous falls and number of medications administered within 72 hr prior to the fall. This scale showed acceptable predictive accuracy. CONCLUSIONS: The newly developed SAK Fall Scale includes five intrinsic and two extrinsic variables and differs from other predictive scales for falls. The findings of this study are broad and the scale, which is easy to apply, can be used worldwide by nurses in health services. In advanced practice, the testing of a new model for fall risk contributes to preventive interventions and thus has an impact on patient safety.

Revisiting Meiosis in Sugarcane: Chromosomal Irregularities and the Prevalence of Bivalent Configurations.

Traditional sugarcane cultivars (Saccharum officinarum) proved highly susceptible to diseases, and this led breeders to progress to interspecific crosses resulting in disease resistance. A backcrossing program to S. officinarum was then required to boost sucrose content. Clonal selection across generations and incorporation of other germplasm into cultivated backgrounds established the (narrow) genetic base of modern cultivars (Saccharum spp.), which have a man-made genome. The genome complexity has inspired several molecular studies that have elucidated aspects of sugarcane genome constitution, architecture, and cytogenetics. However, there is a critical shortage of information on chromosome behavior throughout meiosis in modern cultivars. In this study, we examined the microsporogenesis of a contemporary variety, providing a detailed analysis of the meiotic process and chromosome association at diakinesis, using FISH with centromeric probes. Chromosomal abnormalities were documented by examining high quality preparations of pollen mother cells (700 in total). Approximately 70% of the cells showed abnormalities, such as metaphase chromosomes not lined up at the plate, lagging chromosomes and chromosomal bridges, and tetrad cells with micronuclei. Some dyads with asynchronous behavior were also observed. Due to the hybrid composition of the sugarcane genome, we suggest that bivalent incomplete pairing may occur in the first prophase leading to univalency. The presence of rod bivalents showing the lagging tendency is consistent with a reduction in chiasma frequency. Finally, the presence of chromatin bridges indicates the indirect occurrence of chromosomal inversions, although chromosome fragments were not clearly recognized. Possible reasons for such meiotic abnormalities and the large prevalence of bivalent formation are discussed.

SNP genotyping allows an in-depth characterisation of the genome of sugarcane and other complex autopolyploids.

Many plant species of great economic value (e.g., potato, wheat, cotton, and sugarcane) are polyploids. Despite the essential roles of autopolyploid plants in human activities, our genetic understanding of these species is still poor. Recent progress in instrumentation and biochemical manipulation has led to the accumulation of an incredible amount of genomic data. In this study, we demonstrate for the first time a successful genetic analysis in a highly polyploid genome (sugarcane) by the quantitative analysis of single-nucleotide polymorphism (SNP) allelic dosage and the application of a new data analysis framework. This study provides a better understanding of autopolyploid genomic structure and is a sound basis for genetic studies. The proposed methods can be employed to analyse the genome of any autopolyploid and will permit the future development of high-quality genetic maps to assist in the assembly of reference genome sequences for polyploid species.

Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukey's post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.

As bases protéticas em resina acrílica podem sofrer alteração de cor com o tempo em função do acúmulo de pigmentos em seu interior, porém há carência de informação sobre o efeito do consumo de chimarrão neste processo. Este trabalho avaliou o efeito de cinco bebidas diferentes, incluindo chimarrão, na cor de resinas acrílicas processadas por três técnicas diferentes. Vinte e cinco discos de resina acrílica (3 mm de espessura x 20 mm de diâmetro) foram fabricados a partir de cada uma das técnicas de processamento (P1 ­ polimerização por microondas / resina termopolimerizável por microondas; P2 ­ termopolimerização convencional / resina termopolimerizável convencional e P3 ­ polimerização por microon - das / resina termopolimerizável convencional). Os discos foram aleatoriamente divididos em cinco (n=5) grupos por técnica: G1 ­ água; G2 ­ refrigerante à base de cola; G3 ­ café; G4 ­ chimarrão e G5 ­ vinho tinto, e foram mantidos imersos em cada uma das respectivas soluções por 30 dias a 37 ºC, com trocas das soluções a cada 3 dias. A cor final foi medida na escala CIE-L*a*b* com um colorímetro Konica-Minolta CR-10 e comparada com os valores originais de L*a*b* prévios à imersão de cada corpo-de-prova. Análise de Variância para dois fatores não encontrou diferenças entre as técnicas e apontou diferença estatisticamente significativa (p<0,05) entre as soluções. Teste complementar de Tukey mostrou que as menores variações de cor ocorreram para água e refrigerante à base de cola; o café apresentou a segunda menor variação de cor; o chimarrão apresentou a segunda maior variação enquanto a maior variação de cor foi encontrada para o vinho tinto. Conclusões: Concluiu-se que quase toda solução utilizada provoca mudança de cor nas resinas acrílicas, principalmente com chimarrão e vinho, consideradas distinguíveis por profissionais e clinicamente inaceitáveis respectivamente.

Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine. / Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukeys post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.

Functional markers for gene mapping and genetic diversity studies in sugarcane.

BACKGROUND: The database of sugarcane expressed sequence tags (EST) offers a great opportunity for developing molecular markers that are directly associated with important agronomic traits. The development of new EST-SSR markers represents an important tool for genetic analysis. In sugarcane breeding programs, functional markers can be used to accelerate the process and select important agronomic traits, especially in the mapping of quantitative traits loci (QTL) and plant resistant pathogens or qualitative resistance loci (QRL). The aim of this work was to develop new simple sequence repeat (SSR) markers in sugarcane using the sugarcane expressed sequence tag (SUCEST database). FINDINGS: A total of 365 EST-SSR molecular markers with trinucleotide motifs were developed and evaluated in a collection of 18 genotypes of sugarcane (15 varieties and 3 species). In total, 287 of the EST-SSRs markers amplified fragments of the expected size and were polymorphic in the analyzed sugarcane varieties. The number of alleles ranged from 2-18, with an average of 6 alleles per locus, while polymorphism information content values ranged from 0.21-0.92, with an average of 0.69. The discrimination power was high for the majority of the EST-SSRs, with an average value of 0.80. Among the markers characterized in this study some have particular interest, those that are related to bacterial defense responses, generation of precursor metabolites and energy and those involved in carbohydrate metabolic process. CONCLUSIONS: These EST-SSR markers presented in this work can be efficiently used for genetic mapping studies of segregating sugarcane populations. The high Polymorphism Information Content (PIC) and Discriminant Power (DP) presented facilitate the QTL identification and marker-assisted selection due the association with functional regions of the genome became an important tool for the sugarcane breeding program.