An efficient approach for identifying important biomarkers for biomedical diagnosis

In this paper, we explore the challenges associated with biomarker identification for diagnosis purpose in biomedical experiments, and propose a novel approach to handle the above challenging scenario via the generalization of the Dantzig selector. To improve the efficiency of the regularization method, we introduce a transformation from an inherent nonlinear programming due to its nonlinear link function into a linear programming framework under a reasonable assumption on the logistic probability range. We illustrate the use of our method on an experiment with binary response, showing superior performance on biomarker identification studies when compared to their conventional analysis. Our proposed method does not merely serve as a variable/biomarker selection tool, its ranking of variable importance provides valuable reference information for practitioners to reach informed decisions regarding the prioritization of factors for further investigations.

Analysis of driving factors of spatial distribution of heavy metals in soil of non-ferrous metal smelting sites: Screening the geodetector calculation results combined with correlation analysis

Heavy metals (HMs) discharged from smelting production may pose a major threat to human health and soil ecosystems. In this study, the spatial distribution characteristics of HMs in the soil of a non-ferrous metal smelting site were assessed. This study employed the geodetector (GD) by optimizing the classification condition and supplementing the correlation analysis (CA). The contribution of driving factors, such as production workshop distributions, hydrogeological conditions, and soil physicochemical properties, to the distribution of HMs in soil in the horizontal and vertical dimensions was assessed. The results showed that the main factors underlying the spatial distribution of As, Cd, Hg, Pb, Sb, and Zn in the horizontal direction were the distance from the sintering workshop (the maximum q value of that factor, q=0.28), raw material yard (q=0.14), and electrolyzer (q=0.29), while those in the vertical direction were the soil moisture content (q=0.17), formation lithology (q=0.12), and soil pH (q=0.06). The findings revealed that the CA is a simple and effective method to supplement the GD analysis underlying the spatial distribution characteristics of HMs at site scale. This study provides useful suggestions for environmental management to prevent HMs pollution and control HMs in the soil of non-ferrous metal smelting sites.

Fractional Factorial Designs: An Underutilized Tool for Rapid In Vitro System Development

Anther and microspore culture for producing haploid plants are very complex systems and include general effects where the specific effects must be identified and optimized to develop culture systems capable of producing the large numbers of haploids required by breeding programs. These general effects include genotype, physiological state of the source plant, age of the anthers and microspores, preculture treatments, culture conditions, and culture media. Design of experiments (DoE) is an experimental approach specifically designed to identify and optimize the multiple factors that make up complex systems, and is ideally suited for developing in vitro systems to produce haploids. The basic DoE strategy starts by screening multiple factors thought to affect the responses being measured. Screening identifies factors with large and small effects. Factors with large effects are used to manipulate the system, and are moved to the DoE optimization phase such as response surface methodology. Factors with small or trivial effects are eliminated from further consideration, and this simplifies the system. The basic concepts of fractional factorial designs and how to use them are explained. Fractional factorials are the most important DoE screening tool and are the first experiments run before DoE optimization experiments. To illustrate the unique properties of fractional factorials, a detailed example is provided that includes all of the calculations so that no statistical software is required.

Obstetric Outcome in Pregnant Patients with Low Level of Pregnancy-Associated Plasma Protein A in First Trimester

BACKGROUND

Pregnancy-associated plasma protein A (PAPP-A), is a protease which releases Insulin-like growth factor. The role of this factor is stimulation of cell mitosis, differentiation and trophoblastic invasion of deciduas. Identification of patients with low PAPP-A (under 0.4 MoM in the first trimester has an influence on birth weight, attenuation of fetal growth, preeclampsia, birth and fetal demise.

AIM

The main issue in the study is evaluating an influence of PAPP-A, calculated in the first trimester on the unfavourable outcome of pregnancy.

MATERIAL AND METHODS

Seventy pregnant women with singleton pregnancy underwent first-trimester biochemical screening. The target group were women with PAPP-A below 0.4 MoM, and in control group, PAPP-A were over 0.4 MoM. There was an assessment of the influence on the mode of delivery, gestational week, the presence of intrauterine growth restriction, preeclampsia, temporary birth, intrauterine fetal demise and newborn condition.

RESULTS

In target group, consisted of 35 patients, 16 were delivered at term. From 28 to 37 g.w.- were 7 patient, 22-28 g.w.- 4 and 8 patients were under the 22 g.w (all with fetal demise) there were 19 pretemporary deliveries - 9 with Cesarean Section (SC). In the target group: 5 newborn were with IUGR, 6 women had preeclampsia, 1 had placental abruption. In control group were 35 patients: 28 delivered at term, 9 with SC, 26 vaginal deliveries; with IUGR were 4 newborns. Two newborns were hypertrophic.

CONCLUSION

There is a significant difference in unfavourable outcome in the cases with PAPP-A under 0.4 Mom, particular in the group, with a PAPP-A value under 0.2 MoM. The patients delivered with SC with the main indications in utero hypoxia, growth restriction and elevated blood pressure had PAPP-A between 0.3-0.4 MoM. The patients with intrauterine fetal death and placental abruption in the most of the cases have PAPP-A value under 0.2 MoM. There is a need to be aware in these pregnancies to achieve the preventions of adverse outcome, to decrease perinatal morbidity and mortality.