Prevalence estimates for fragile X syndrome vary considerably. This systematic review and meta-analysis was conducted to provide an accurate prevalence estimate for this disorder using primary ...publications in PubMed, Embase, and the Cochrane library. Data were pooled using Bayesian fixed-effects and random-effects models. Primary analyses assessed the frequency of the full mutation and premutation in males and females in the total population (no bias against individuals with intellectual disability) and in female carriers of the premutation in normal populations (biased against individuals with intellectual disability), based on diagnosis by polymerase chain reaction or Southern blotting. A sensitivity analysis included studies using any diagnostic testing method and conference abstracts. Sixty-eight recorded observations provided data for the primary (56 observations) and sensitivity (12 observations) analysis. Using the random-effects model, frequency of the full mutation was 1.4 (95% CI: 0.1-3.1) per 10,000 males and 0.9 (95% CI: 0.0-2.9) per 10,000 females (1:7,143 and 1:11,111, respectively) in the total population. The premutation frequency was 11.7 (95% CI: 6.0-18.7) per 10,000 males and 34.4 (95% CI: 6.3-83.3) per 10,000 for females (1:855 and 1:291, respectively) in the total population. The prevalence of female carriers of the premutation in the normal population was 34.4 (95% CI: 8.9-60.3) per 10,000, or 1:291. Sensitivity analyses resulted in similar prevalence estimates but with wider heterogeneity. Prevalence estimates for the full mutation from this meta-analysis are lower than those in previous reviews of fragile X syndrome epidemiological data.
Interval-censored data can arise in questionnaire-based studies when the respondent gives an answer in the form of an interval without having pre-specified ranges. Such data are called self-selected ...interval data. In this case, the assumption of independent censoring is not fulfilled, and therefore the ordinary methods for interval-censored data are not suitable. This paper explores a quantile regression model for self-selected interval data and suggests an estimator based on estimating equations. The consistency of the estimator is shown. Bootstrap procedures for constructing confidence intervals are considered. A simulation study indicates satisfactory performance of the proposed methods. An application to data concerning price estimates is presented.
The paper explores a testing problem which involves four hypotheses, that is, based on observations of two random variables
X
and
Y
, we wish to discriminate between four possibilities: identical ...survival functions, stochastic dominance of
X
over
Y
, stochastic dominance of
Y
over
X
, or crossing survival functions. Four-decision testing procedures for repeated measurements data are proposed. The tests are based on a permutation approach and do not rely on distributional assumptions. One-sided versions of the Cramér–von Mises, Anderson–Darling, and Kolmogorov–Smirnov statistics are utilized. The consistency of the tests is proven. A simulation study shows good power properties and control of false-detection errors. The suggested tests are applied to data from a psychophysical experiment.
Traditional sourdoughs in Bulgaria were almost extinct during the centralized food production system. However, a rapidly developing trend of sourdough revival in the country is setting the demand for ...increased production and use of commercial starter cultures. The selection of strains for such cultures is based on geographical specificity and beneficial technological properties. In this connection, the aim of this study was to isolate, identify and characterize lactic acid bacteria (LAB) and yeasts from typical Bulgarian sourdoughs for the selection of strains for commercial sourdough starter cultures. Twelve samples of typical Bulgarian sourdoughs were collected from different geographical locations. All samples were analyzed for pH, total titratable acidity and dry matter content. Enumeration of LAB and yeast was also carried out. Molecular identification by 16S rDNA sequence analysis was performed for 167 LAB isolates, and 106 yeast strains were identified by ITS1-5.8S-ITS2 rRNA gene partial sequence analysis. The LAB strains were characterized according to their amylolytic and proteolytic activity and acidification capacity, and 11 strains were selected for further testing of their antimicrobial properties. The strains with the most pronounced antibacterial and antifungal activity are listed as recommended candidates for the development of starter cultures for sourdoughs or other food products.
The regulatory framework regarding food labelling aims to ensure food safety and prevent consumer misleading and food fraud. However, legal compliance cannot be controlled without the use of reliable ...analytical methods. Polymerase chain reaction (PCR) with species-specific primers is considered the most reliable analytical tool for species identification in various raw and processed foods. Duplex PCR methods allow the simultaneous detection of two species within a product, which may considerably reduce analytical time, effort and price. Therefore, the objective of our study was to develop a duplex PCR method for detecting beef and pork in raw and processed meat products. Our research resulted in elaborating a highly specific method, with LOD for each sequence of 0.01 % target DNA in two-component meat mixtures. The application of the duplex PCR for authentication of raw and processed meat products on Bulgarian market showed that 45% of the analysed meat products had labelling incompliances regarding the content of beef and pork. These results demonstrate the need for more stringent and authenticity control in the meat processing sector and at the market by using rapid and reliable analytical methods in order to reduce the current levels of food fraud and protect consumer’s rights.
Sourdough is a spontaneously formed, complex microbial ecosystem of various lactic acid bacteria (LAB) and yeast which, by producing specific metabolites, determines the quality of the baked ...products. In order to design and control the sourdough with preferred nutritional characteristics, it is crucial that the LAB diversity of the product of interest be elucidated.
Using the opportunities of next-generation sequencing (NGS) of the V1-V3 hypervariable gene region of 16S rRNA, we studied the microbial ecosystem of a whole grain sourdough made of
, originating from Southwestern Bulgaria. Since the DNA extraction method is considered crucial for the accuracy of the sequencing results, as it can introduce significant differences in the examined microbiota, we used three different commercial kits for DNA isolation and analyzed their impact on the observed bacterial diversity.
All three DNA extraction kits provided bacterial DNA which passed quality control and was successfully sequenced on Illumina MiSeq platform. The results received from the different DNA protocols showed variations in the microbial profiles. Alpha diversity indices (ACE, Chao1, Shannon, and Simpson) were also different among the three groups of results. Nevertheless, a strong dominance of phylum Firmicutes, class Bacilli, order Lactobacillales, represented mostly by family Lactobacillaceae, genus
(relative abundance of 63.11-82.28%) and family Leuconostocaceae, genus
(relative abundance of 3.67-36.31%) was observed.
and
with relative abundance of 16.15-31.24% and 6.21-16.29% respectively, were the two dominant species identified in all three DNA isolates.
The presented results give insight into the taxonomic composition of bacterial community of a specific Bulgarian sourdough. Having in mind that the sourdough is a difficult matrix for DNA isolation on the one hand, and that there is no standardized DNA extraction protocol for this matrix on the other hand, this pilot study aims to give a small contribution to the future establishment and validation of such a protocol, which will allow accurate assessment of the specific microbiota of sourdough samples.
Interval-censored data may arise in questionnaire surveys when, instead of being asked to provide an exact value, respondents are free to answer with any interval without having pre-specified ranges. ...In this context, the assumption of noninformative censoring is violated, and thus, the standard methods for interval-censored data are not appropriate. This paper explores two schemes for data collection and deals with the problem of estimation of the underlying distribution function, assuming that it belongs to a parametric family. The consistency and asymptotic normality of a proposed maximum likelihood estimator are proven. A bootstrap procedure that can be used for constructing confidence intervals is considered, and its asymptotic validity is shown. A simulation study investigates the performance of the suggested methods.
Sourdough has played a significant role in human nutrition and culture for thousands of years and is still of eminent importance for human diet and the bakery industry. Lactobacillus sanfranciscensis ...is the predominant key bacterium in traditionally fermented sourdoughs.The genome of L. sanfranciscensis TMW 1.1304 isolated from an industrial sourdough fermentation was sequenced with a combined Sanger/454-pyrosequencing approach followed by gap closing by walking on fosmids. The sequencing data revealed a circular chromosomal sequence of 1,298,316 bp and two additional plasmids, pLS1 and pLS2, with sizes of 58,739 bp and 18,715 bp, which are predicted to encode 1,437, 63 and 19 orfs, respectively. The overall GC content of the chromosome is 34.71%. Several specific features appear to contribute to the ability of L. sanfranciscensis to outcompete other bacteria in the fermentation. L. sanfranciscensis contains the smallest genome within the lactobacilli and the highest density of ribosomal RNA operons per Mbp genome among all known genomes of free-living bacteria, which is important for the rapid growth characteristics of the organism. A high frequency of gene inactivation and elimination indicates a process of reductive evolution. The biosynthetic capacity for amino acids scarcely availably in cereals and exopolysaccharides reveal the molecular basis for an autochtonous sourdough organism with potential for further exploitation in functional foods. The presence of two CRISPR/cas loci versus a high number of transposable elements suggests recalcitrance to gene intrusion and high intrinsic genome plasticity.
Purpose: The present study is aimed at the analysis of the extent to which the collected taxes and the structure thereof have an impact on the economic growth of the Balkan region. ...Design/Methodology/Approach: Linear regression models have been developed and applied. Data for the period 2005-2018 have been used from the annual reports on the execution of the consolidated budget, published by the Ministries of finance of the Balkan countries and macroeconomic data from their Central banks and National statistical institutions. The estimation is made using the ordinary least squares (OLS) method. Findings: The results of the applied models show that the increase of the tax burden during the period under review and the restructuring of the tax systems have a restraining effect in the search for higher economic growth. The countries in the Balkan region where the tax burden is lower, as well as the countries where indirect taxes occupy a larger relative share, show better economic results. Practical Implications: The present study provides a good starting point for the conduct of fiscal policy by the ruling governments in the countries of the Balkan region. The guidelines are on how these governments manage the tax burden on the economic agents and what the appropriate structure of applicable taxes would be to achieve sustainable economic development. Originality/Value: The study contributes to the scientific literature by conducting an extensive analysis of some of the already studied relationships between taxation and economic growth, on the one hand, and examines the extent to which opinions already expressed are applicable to Balkan countries’ policy, on the other hand. The study also identifies the reason for some of the dynamic processes in the Balkan economies in the period 2005-2018.
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