Impact of Extracellular DNA on Architectural Parameters of Leptospira biflexa Biofilm.

Extracellular DNA (eDNA) is a major component of bacterial biofilms. In this study, we performed a three-dimensional analysis of Leptospira biofilm using advanced imaging by confocal laser scanning microscopy (CLSM) and multi-parameter analysis by COMSTAT 2 software, with quantification of Leptospira and eDNA fluorescence. To investigate the role of eDNA in Leptospira biofilm, we treated Leptospira biflexa biofilms with DNase I enzyme (DNase), which digested eDNA, and compared DNase treated biofilms and controls. There was a significant reduction of the biomass of biofilms treated with DNase, by spectrophotometry and COMSTAT analysis. The multiparameter analysis evidenced for DNase-treated biofilms a significant decrease in the surface area and the average thickness; opposing to a significant augmentation of the surface/biovolume ratio and the roughness coefficient (Ra*), when compared to controls. We analyzed the parameters of DNase-treated biofilms by Pearson's correlation coefficient and found significant positive correlations between biomass and average thickness; biomass and surface area; surface area and average thickness. On the other hand, there were significant negative correlations between Ra* and biomass; Ra* and average thickness; Ra* and surface area. These findings suggest that eDNA digestion results in biofilm instability and alteration of the three-dimensional architecture, justifying the negative correlation between Ra* and the above-mentioned parameters. In conclusion, our study showed that eDNA digestion produced a massive structural loss, instability, and dramatic changes in the three-dimensional architecture of Leptospira biflexa biofilm. These findings contribute to a better understanding of the role of eDNA and highlight the importance of eDNA as a key component in Leptospira biofilms.

A dimension reduction technique applied to regression on high dimension, low sample size neurophysiological data sets.

BACKGROUND: A common problem in neurophysiological signal processing is the extraction of meaningful information from high dimension, low sample size data (HDLSS). We present RoLDSIS (regression on low-dimension spanned input space), a regression technique based on dimensionality reduction that constrains the solution to the subspace spanned by the available observations. This avoids regularization parameters in the regression procedure, as needed in shrinkage regression methods. RESULTS: We applied RoLDSIS to the EEG data collected in a phonemic identification experiment. In the experiment, morphed syllables in the continuum /da/-/ta/ were presented as acoustic stimuli to the participants and the event-related potentials (ERP) were recorded and then represented as a set of features in the time-frequency domain via the discrete wavelet transform. Each set of stimuli was chosen from a preliminary identification task executed by the participant. Physical and psychophysical attributes were associated to each stimulus. RoLDSIS was then used to infer the neurophysiological axes, in the feature space, associated with each attribute. We show that these axes can be reliably estimated and that their separation is correlated with the individual strength of phonemic categorization. The results provided by RoLDSIS are interpretable in the time-frequency domain and may be used to infer the neurophysiological correlates of phonemic categorization. A comparison with commonly used regularized regression techniques was carried out by cross-validation. CONCLUSION: The prediction errors obtained by RoLDSIS are comparable to those obtained with Ridge Regression and smaller than those obtained with LASSO and SPLS. However, RoLDSIS achieves this without the need for cross-validation, a procedure that requires the extraction of a large amount of observations from the data and, consequently, a decreased signal-to-noise ratio when averaging trials. We show that, even though RoLDSIS is a simple technique, it is suitable for the processing and interpretation of neurophysiological signals.

COVID-19 pneumonia: A review of typical CT findings and differential diagnosis.

The standard of reference for confirming COVID-19 relies on microbiological tests such as real-time polymerase chain reaction (RT-PCR) or sequencing. However, these tests might not be available in an emergency setting. Computed tomography (CT) can be used as an important complement for the diagnosis of COVID-19 pneumonia in the current epidemic context. In this review, we present the typical CT features of COVID-19 pneumonia and discuss the main differential diagnosis.

Automatic loudness control in short-form content for broadcasting.

During the early years of the International Telecommunication Union (ITU) loudness calculation standard for sound broadcasting [ITU-R (2006), Rec. BS Series, 1770], the need for additional loudness descriptors to evaluate short-form content, such as commercials and live inserts, was identified. This work proposes a loudness control scheme to prevent loudness jumps, which can bother audiences. It employs short-form content audio detection and dynamic range processing methods for the maximum loudness level criteria. Detection is achieved by combining principal component analysis for dimensionality reduction and support vector machines for binary classification. Subsequent processing is based on short-term loudness integrators and Hilbert transformers. The performance was assessed using quality classification metrics and demonstrated through a loudness control example.

Synergistic in vitro antioxidant activity and observational clinical trial of F105, a phytochemical formulation including Citrus bergamia, in subjects with moderate cardiometabolic risk factors.

We examined the clinical safety and efficacy of F105 in 11 subjects with moderate dyslipidemia. F105 is a combination of bergamot fruit extract (Citrus bergamia, BFE) and 9 phytoextracts selected for their ability to improve the antioxidant and anti-inflammatory activity of BFE. In vitro F105 exhibited a synergistic inhibition of oxygen radical absorbing capacity, peroxynitrite formation, and myeloperoxidase activity. Following 12 weeks of F105 daily, no treatment-related adverse events or changes in body mass were seen. Statistically significant changes were noted in total cholesterol (-7.3%), LDL-cholesterol (-10%), non-HDL cholesterol (-7.1%), cholesterol/HDL (-26%), and apolipoprotein B (-2.8%). A post hoc analysis of 8 subjects with HbA1c > 5.4 and HOMA-IR score > 2 or elevated triglycerides revealed additional statistically significant changes in addition to those previously observed in all subjects including triglycerides (-27%), oxLDL (-19%), LDL/HDL (-25%), triglycerides/HDL (-27%), oxLDL/HDL (-25%), and PAI-1 (-37%). A follow-up case report of a 70-year-old female patient, nonresponsive to statin therapy and placed on F105 daily, demonstrated improved cardiometabolic variables over 12 weeks similar to the subgroup. In summary, F105 was clinically well-tolerated and effective for ameliorating dyslipidemia in subjects with moderate cardiometabolic risk factors, particularly in the individuals with HbA1c > 5.4%.

Relating movement recurrence and expressive timing patterns in music performances.

In this study the movement patterns of ten expert musicians are quantitatively related to expressive timing patterns and the music structure during performances. The hypothesis is that ancillary gestures recurrently employed are closely related to expressive intentions, and that the expressive content imposed in key musical passages is thus reflected in the patterns of gestural recurrence. A movement and an audio analysis of 30 clarinet performances of a Brahms' excerpt are compared. Results show direct correlations between the recurrence pattern of clarinetists' ancillary movements and expressive bar duration manipulations employed by them, associated with melodic phrasing and harmonic transitions.

New studies of second and fourth digit ratio as a morphogenetic trait in subjects with congenital adrenal hyperplasia.

OBJECTIVES: Congenital adrenal hyperplasia (CAH) is a disease that occurs during fetal development and can lead to virilization in females or death in newborn males if not discovered early in life. Because of this there is a need to seek morphological markers in order to help diagnose the disease. In order to test the hypothesis that prenatal hormones can affect the sexual dimorphic pattern 2D:4D digit ratio in individual with CAH, the aim of this study was to compare the digit ratio in female and male patients with CAH and control subjects. METHODS: The 2D:4D ratios in both hands of 40 patients (31 females-46, XX, and 9 males-46, XY) were compared with the measures of control individuals without CAH (100 males and 100 females). RESULTS: Females with CAH showed 2D:4D ratios typical of male controls (0.950 and 0.947) in both hands (P < 0.001). In CAH males the left hand 2D:4D ratio (0.983) was statistically different from that of male controls (P < 0.05). CONCLUSIONS: These finding support the idea that sexual dimorphism in skeletal development in early fetal life is associated with differences between the exposure to androgens in males and females, and significant differences associated with adrenal hyperplasia. Although the effects of prenatal androgens on skeletal developmental are supported by numerous studies, further investigation is yet required to clarify the disease and establish the digit ratio as a biomarker for CAH.

Vibrato and tremor extent spectrum: algorithm and applications.

This work investigated the measurement of vibrato and tremor extent values. Related works have not explored the possibility of measuring extent in the spectra of fundamental frequency (f(0)) low-frequency undulations. It is shown here that by canceling average (DC) values and baseline drifts of f(0) contours, as well as weighting the respective spectra by the time window DC value, extent measures can be promptly obtained in the frequency domain. The method is illustrated with measurements from synthetic and human data.