This paper proposes an improvement to a recent Peak-to-Average-Power-Ratio (PAPR) reduction technique for Orthogonal Frequency Division Multiplexing (OFDM), the GreenOFDM. This technique, which is inspired by SeLected Mapping (SLM), generates several waveform candidates using a given number of Inverse Fast Fourier Transforms (IFFT), and selects the one with the lowest PAPR for the transmission of the OFDM symbol. In GreenOFDM, we show that for (U) IFFTs, it provides better PAPR reduction capabilities than SLM-OFDM as it increases the number of waveform candidates from U (available for SLM-OFDM) to U^2/4. In this work, we propose a simple and clever extension of the GreenOFDM that further increases the number of waveform candidates by a factor 4 (from U^2/4 to U^2), or equivalently reduces by a factor of 2 the number of IFFTs for a same PAPR performance. Compared to SLM-OFDM, the improved GreenOFDM technique reduces the complexity by requiring only the square-root of the number of IFFTs for a same PAPR reduction performance.

This study focused on the characterization of lactic acid bacteria (LAB) in a renowned traditional Italian cheese, Pecorino di Farindola, to select an autochthonous culture and investigate its po-tential for the improvement of safety and functional properties. Two hundred and six LAB isolated throughout production and maturation from nine cheese lots of three farms were identified by 16S rRNA gene sequencing and tested for the presence of genes encoding virulence factors, vancomycin resistance (for enterococci), biogenic amines (BAs) and bacteriocin production, for antimicrobial activity, and for the capacity to survive in the gastro-intestinal tract (GIT) based on tolerance to low pH and bile salts and adhesion to CaCo-2 cells. A Lacticaseibacillus paracasei isolate was used in cheese making and determined a decline of spiked Listeria monocytogenes and Escherichia coli O157 faster than in control cheese. The autochthonous bacterial groups were numerically unaffected, apart from lactobacilli that were recovered in higher numbers in the cheese with added L. paracasei. Based on Repetitive Extragenic Palyndrome (Rep) PCR profiles, the added strain possibly dominated until day 88 in cheese. Results encourage further trials with autochthonous cultures to efficiently inhibit hazardous bacteria and enrich a functional microbiota in Pecorino di Farindola and similar cheeses.

Human pluripotent stem cells (hPSCs) have widespread potential biomedical applications. There is a need for large-scale in vitro production of hPSCs, and optimal culture methods are vital in achieving this. Physiological oxygen (2% O2) improves key hPSCs attributes, including genomic integrity, viability, and clonogenicity, however, its impact on hPSC metabolism remains un-clear. Here, Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) was used to detect and quantify metabolic Volatile Organic Compounds (VOCs) in the headspace of hPSCs and their differentiated progeny. hPSCs were cultured in either 2% O2 or 21% O2. Media was collected from cell cultures and transferred into glass bottles for SIFT-MS measurement. The VOCs acetaldehyde and dimethyl sulfide (DMS)/ethanethiol were significantly increased in undifferentiated hPSCs compared to their differentiating counterparts, and these observations were more apparent in 2% O2. Pluripotent marker expression was consistent across both O2 concentrations tested. Transcript levels of ADH4, ADH5, and CYP2E1, encoding enzymes involved in converting ethanol to acetaldehyde, were upregulated in 2% O2, and chemical inhibition of ADH and CYP2E1 decreased acetaldehyde levels in hPSCs. Acetaldehyde and DMS/ethanethiol may be indicators of altered metabolism pathways in physiological oxygen culture conditions. The identification of non-destructive biomarkers for hPSC characterization has the potential to facilitate large-scale in vitro manufacture for future biomedical application.