Short-term glacier area changes, glacier geometry dependence, and regional climatic variations forcing, King George Island, Antarctica.

This study investigates the transient snowline (TSL) altitude for summer 2020, as well as glacial area loss in King George Island Icefields since 1988 using Sentinel-1 and 2 and Landsat Thematic Mapper (TM) imagery. Trends and anomalies in atmospheric temperature, U-wind, and V-wind were examined using ERA5 solutions. Results show the wet-snow zone corresponds to values of ≤ -13dB, and 44.3% of the glacial area is located above the TSL (≥ 300 m). Glacial area for 2020 is 999.95 km², and losses in the period represent 104.9 km² (error <1%) - a retreat of 3.17 km² / year. Glaciers in Keller Peninsula and Bellingshausen Dome lost the most area (28% and 17%, respectively) and did not have a TSL in 2020; followed by Warszawa (15%), Kraków (13%), and Eastern (10%), where the TSL was verified. Percentage area loss values increased with decreases in dimensions, area above TSL, and maximum elevation. Calving glaciers with ice-flow toward deeper and steeper submarine sectors (Bransfield Strait) exhibited greater glacier variations. The trend in warming atmospheric temperature was greater in the Bransfield Strait than in the Drake Passage. TSL and retreat difference between glaciers were influenced by climatic and ocean input, as well as multiple environmental factors.

Dietary Fruit By-Products Improve the Physiological Status of Nile Tilapias (Oreochromis niloticus) and the Quality of Their Meat.

By-products from fruit industrialization retain nutritional and functional components; thus, they may find use in animal feeding. This study aimed to assess the effects of dietary fruit industrial by-products on the tilapias blood biochemical and oxidative parameters and on the composition and lipid peroxidation of their fillets. Four diets were supplied to the tilapias: a C-control diet, with no fruit meal, and three diets containing 5% of either acerola (ACM), apple (APM) or grape (GRM) meal. The phenolic compounds and the carotenoids in the meals and their antioxidant capacities were measured. Fish were weighed and measured for the calculation of the growth performance data, their blood was analyzed for health and oxidative status biomarkers and their fillets were analyzed for proximal composition and lipid peroxidation. Grape meal had the highest concentration of phenolics and carotenoids and the highest antioxidant activity, followed by acerola and apple meals. The productive performance was similar among the treatments. The fruit by-product diets either maintained or improved the biochemical biomarkers of health and improved the oxidative status of the fish. The fruit by-product diets increased the concentration of lipids in the fillets and slowed down the onset of the lipid peroxidation during frozen storage.

How Personalization Affects Motivation in Gamified Review Assessments.

Personalized gamification aims to address shortcomings of the one-size-fits-all (OSFA) approach in improving students' motivations throughout the learning process. However, studies still focus on personalizing to a single user dimension, ignoring multiple individual and contextual factors that affect user motivation. Unlike prior research, we address this issue by exploring multidimensional personalization compared to OSFA based on a multi-institution sample. Thus, we conducted a controlled experiment in three institutions, comparing gamification designs (OSFA and Personalized to the learning task and users' gaming habits/preferences and demographics) in terms of 58 students' motivations to complete assessments for learning. Our results suggest no significant differences among OSFA and Personalized designs, despite suggesting user motivation depended on fewer user characteristics when using personalization. Additionally, exploratory analyses suggest personalization was positive for females and those holding a technical degree, but negative for those who prefer adventure games and those who prefer single-playing. Our contribution benefits designers, suggesting how personalization works; practitioners, demonstrating to whom the personalization strategy was more or less suitable; and researchers, providing future research directions. Supplementary Information: The online version contains supplementary material available at 10.1007/s40593-022-00326-x.

Motivation and anxiety during the second COVID-19 lockdown in gym exercisers: The mediating role of affects and satisfaction with life.

The present study aimed to analyze the association between motivation (self-determined and non-self-determined motivation), positive and negative affect, life satisfaction and state-anxiety in a sample of gym exercisers, during the 2nd COVID-19 lockdown in Portugal. Also, we aimed to analyze the possible mediating role of positive and negative affect and life satisfaction in the relationship between motivation and levels of state-anxiety. A total of 201 gym participants (30.42 ± 11.22) were enrolled in the present study, of which 116 (57.7%) were women and 85 (42.3%) were men. The survey included sociodemographic data as well as the subsequently validated instruments: the State-Trait Anxiety Inventory, the Positive and Negative Affect Schedule, and the Satisfaction with Life Scale. The results revealed a positive association between state-anxiety and negative affect (r = .69), controlled motivation (r = .33), and autonomous motivation (r = .25). Still, state-anxiety was negatively associated with positive affect (r = -.40) and with satisfaction with life (r = -.43),. In addition, the results of mediation analysis, revealed inconsistent mediation of positive affect and life satisfaction in the relationship between autonomous motivation and state-anxiety. However, a total mediation was observed through negative affect and life satisfaction in the relationship between controlled motivation and anxiety since the indirect effect (ß = .27) is higher than the direct effect (ß = .06). Overall, the results reinforce that positive affect and satisfaction with life could act as a possible buffer against state-anxiety in gym exercisers and, thus, should be considered in future interventions and studies.

Intrinsically conductive polymers hybrid bilayer films for the fluorescence molecular diagnosis of the Zika virus.

In 2016, the Zika virus (ZIKV) infection became a major public health problem, after the discovery that an alarming increase in the number of Brazilian newborns with microcephaly could be associated with the occurrence of this viral disease during the pregnancy of their mothers. The urgent need for simple diagnostic methods that allow rapid screening of suspected cases has stimulated the search for low-cost devices capable of detecting specific sequences of nucleic acids. The present work describes the development of nanostructured films formed by bilayers of conjugated polymers for rapid detection of the presence of Zika virus DNA, via fluorescence methods. For this, we initially deposited alternating layers of polyaniline (PANI) and polypyrrole (PPY) on the surface of polyethylene terephthalate (PET) sheets. The films obtained were then characterized by SEM, UV-Vis, ATR-FTIR, and contact angle measurements. For their use as quenchers for the diagnosis of Zika, a single DNA strand-specific for ZIKV was labeled with a fluorophore (FAM-ssDNA). We determined the time required for the saturation of the interaction between probe FAM-ssDNA and the film (180 min) and the time for the maximal hybridization between FAM-ssDNA and target DNA to occur (60 min). The detection limits were estimated as 345 pM and 278 pM for the PET/PPY-PANI and PET/PANI-PPY hybrid films, respectively. The simplicity of the procedure, coupled with the fact that a positive/negative response can be obtained in less than 60 min, suggests that the proposal of using these polymeric bilayer films is a promising methodology for the development of rapid molecular diagnostic tests.

DNA purification using a novel γ-Fe2O3/PEDOT hybrid nanocomposite.

We report the synthesis and characterization of a new hybrid magnetic composite formed by the enveloping of magnetic iron oxide nanoparticles (γ-NP) with chains of the conductive polymer PEDOT, and its use for the efficient separation of DNA molecules from complex biological samples, allowing the high yield separation of a pure and high-quality DNA fraction. The successful formation of the γ-NP/PEDOT composite was confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy, UV visible spectroscopy (UV-Vis), and magnetic hysteresis loop measurements. The nanocomposites showed an excellent capacity of DNA adsorption (Qe âˆ¼ 248 mg/g) in a model system consisting of salmon sperm DNA. When the γ-NP/PEDOT was used in protocols to extract the DNA from complex samples, the corresponding yield was in the range of 6.4 µg (blood) and 7.3 µg (bacteria), as evaluated quality by UV-Vis, PCR analysis, and electrophoresis assays. We also established that the captured DNA does not need to be detached from the nanocomposite for use as seeding material in PCR amplification experiments. These results and the simplicity of the protocols indicate that the γ-NP/PEDOT composite is a promising DNA absorbent, being competitive with the commercially available magnetic purification kits.

Wireless technologies for the connectivity of the future.

This Special Issue originates from the international conference EuCNC 2020 (European Conference on Networks and Communications), which was planned to be held in June 2020 in Dubrovnik (Croatia), but due to the COVID-19 pandemic was changed to an Online Conference. The Technical Programme Chairs of the conference have selected the best papers and invited authors to submit an extended version of their paper, by at least one third of their length. Only the top ranked papers were invited to this Special Issue, in order to fulfil its purpose. The main target was to collect and present quality research contributions in the most recent activities related to systems and networks beyond 5G, already presenting ideas for 6G. Through this Special Issue, the state-of-the-art is presented and the new challenges are highlighted, regarding the latest advances on systems and network perspectives that are already being positioned beyond 5G, bridging as well with the evolution of 5G, including applications and trials. Therefore, the motivation for this Special Issue is to present the latest and finest results on the evolution of research of mobile and wireless communications, coming, but not exclusively (since EuCNC is a conference open to the whole research community), from projects co-financed by the European Commission within its R&D programmes.

The interplay between internal and external load parameters during different strength training sessions in resistance-trained men.

External load influences internal load in resistance training (RT). The purpose of the present study was to compare the total volume-load, perceptual and stress responses during three different RT protocols. Twelve resistance-trained men completed three different RT protocols with the back squat and bench press exercises: (1) power (POW) (5 sets of 6 repetitions at 50%1RM, 2-min of rest), (2) hypertrophy (HYP) (5 sets-to-failure at 75%1RM, 2-min of rest), and (3) strength (STR) (5 sets-to-failure at 90%1RM, 3-min of rest). Volume-load (kg × reps.), session rating of perceived exertion (sRPE), training impulse (TRIMP; reps. × sRPE), cortisol, immunoglobulin A (IgA), lactate, and creatine kinase (CK) were assessed before and/or after the sessions. HYP was the most demanding session in terms of volume-load (p < 0.001), TRIMP (p < 0.001), cortisol (p = 0.001), lactate (p < 0.001), and CK (p = 0.001). Despite POW exhibited a greater volume-load than STR (p = 0.016), the latter exhibiting a greater sRPE (p < 0.001), and a greater post-session CK (p = 0.05). However, the TRIMP of STR and POW were not statistically different (152 vs. 260 AU; p = 0.089). These specific responses could be meditated by the presence of muscular failure. When pooling all the sessions, significant correlations were revealed among external and internal stress markers (r = 0.35-0.80; p ≤ 0.05). The use of TRIMP could be recommended as a simple and valid monitoring tool which integrates into a single parameter the internal and the external loads of RT sessions.

Assessment of functional performance in Chagas heart disease by Human Activity Profile questionnaire.

PURPOSE: To verify the association between Human Activity Profile and functional capacity, functional class and systolic function of the patients with Chagas heart disease (CHD). METHODS: Sixty-two patients with CHD were evaluated by echocardiography, maximal exercise testing and Human Activity Profile questionnaire. The sample was stratified, according to the values of peak oxygen uptake (low or normal), functional class (symptomatic or asymptomatic), and left ventricular ejection fraction (preserved or systolic dysfunction). Linear regression and two-group comparisons analyses were used. Receiver-operating characteristic analysis was used to determine different cutoff values of the Human Activity Profile for low peak oxygen uptake prediction. RESULTS: Peak oxygen uptake was an independent predictor of Human Activity Profile (R2-adjusted = 0.27). Patients with low peak oxygen uptake had lower scores in Human Activity Profile [difference of 6.9 (95%CI 2.5-11.4)] than those with normal peak oxygen uptake. Symptomatic patients also showed lower scores when compared to the asymptomatic [difference of 6.2 (95%CI 1.7-10.8)]. There was no difference between left ventricular ejection fraction classes. The Human Activity Profile score of 76.5 was the optimal cut point value in predicting low peak oxygen uptake (sensitivity = 66.0% and specificity = 71.8%). CONCLUSION: The Human Activity Profile questionnaire is associated with functional capacity of patients with CHD and is able to identify individuals with low peak oxygen uptake.Implications for rehabilitationFunctional impairment is one of the most common clinical findings in all stages and is an important predictor of poor prognosis of the Chagas heart disease;A patient-derived measure of functional capacity is potentially useful in the setting of the Chagas heart disease;The Human Activity Profile questionnaire is effective in the identification of patients with Chagas heart disease with functional impairment and may be a valid method for functional evaluation.

Kinetics and thermodynamic studies of Methyl Orange removal by polyvinylidene fluoride-PEDOT mats.

We report the preparation of poly(3,4-ethylene dioxythiophene) (PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange (MO) from aqueous media. This novel adsorbent material can be used to selectively remove MO on a wide pH range (3.0-10.0), with a maximum capacity of 143.8 mg/g at pH 3.0. When used in a recirculating filtration system, the maximum absorption capacity was reached in a shorter time (20 min) than that observed for batch mode experiments (360 min). Based on the analyses of the kinetics and adsorption isotherm data, one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic. Besides, considering the estimated values for the Gibbs energy, and entropy and enthalpy changes, it was established that the adsorption process is spontaneous and occurs in an endothermic manner. The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles, without significant loss of their characteristics. We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.

Spinel Cobalt Ferrite Nanoparticles for Sensing Phosphate Ions in Aqueous Media and Biological Samples.

Phosphate ions perform a variety of functions in metabolic processes and are essential for all living organisms. The determination of the concentration of phosphate ions is useful in clinical diagnosis of various diseases as an inadequate phosphate level could lead to many health problems. In the search for a cost-effective method of fast monitoring, we investigated the use of cobalt ferrite nanoparticles (CoFeNPs) in the selective recognition of phosphate ions dissolved in aqueous media and more complex samples, such as human blood serum. We prepared these NPs by a chemical coprecipitation route and subjected them to annealing at 600 °C for 1 h. The successful formation of the NPs was confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and hysteresis loop measurements. The NPs exhibited a ferrimagnetic behavior, a spinel-type crystalline structure, and hexagonal shape in the nanoscale range. We demonstrated that CoFeNPs containing immobilized fluorescent-labeled single-chain DNA (ssDNA*) probes can be applied for the fast selective detection of phosphate ions dissolved in a liquid medium. We have explored the fact that phosphate groups can displace ssDNA* probes attached to the nanoparticles, therefore causing a perceptible change in the fluorescence signal of the supernatant liquid. This detection method has been tested for the sensing of phosphate ions present both in aqueous solutions and in biological samples, with excellent selectivity and a low limit of detection (∼1.75 nM).

On the modelling of wavepacket scattering noise with coherence effects.

An investigation of a wavepacket model for free-jet and jet-surface interaction noise was conducted. The source term for the axisymmetric mode was extracted from a Mach 0.9 jet large eddy simulation and employed to adjust the parameters of a simple source model. Streamwise coherence decay, in particular, was considered. The source model was propagated with both the free-field and tailored Green's function for a semi-infinite flat plate positioned at a distance of r/D = 1 from the jet axis. Significant deviations were observed in the prediction of the low-angle directivity of the isolated jet as well as in the reproduction of the characteristics of the source field. However, the effects of trailing edge noise were well reproduced. The installed jet case, at the region dominated by trailing-edge scattering, showed very little sensitivity to the coherence decay, a crucial feature in the isolated jet case. In this sense, the modelling of the installed-jet case proved to be much simpler.

A novel nucleic acid fluorescent sensing platform based on nanostructured films of intrinsically conducting polymers.

When fluorophores attach to nanostructured films of intrinsically conducting polymers (ICPs), a quenching of their fluorescence may occur. We have exploited these characteristics for the development of polymeric films that can be used in a simple and efficient molecular diagnosis protocol based on the selective detection of nucleic acids. Our procedure rests on the fact that the fluorescence of 6-carboxyfluorescein-labeled single-stranded DNA (FAM-ssDNA) probes is quenched upon their immobilization on nanostructured ICP - polypyrrole (PPY) and polyaniline (PANI) - films deposited on polyethylene terephthalate (PET) substrates. Hybridization occurs whenever a sample with the complementary sequence is brought in contact with the immobilized probe, with the newly formed ds-DNA chains detaching from the flexible polymeric film and causing the restoration of the fluorescence. This sensing system exhibits a low background signal that depends on both the thickness and hydrophobicity of the films. As a model system, we used a FAM-ssDNA probe specific for the Leishmania infantum parasite. The results confirm this procedure as a simple, fast and highly sensitive scheme for the recognition of the target DNA, with a detection limit of the 1.1 nM and 1.3 nM for the PPY/PET and PANI/PET films, respectively. In addition, this biosensor has excellent stability and exhibits a good and reproducible performance even when used for the direct detection of ssDNA in relatively complex biological samples.

Effects of Triple Cryoenergy Application on Lesion Formation and Coronary Arteries in the Developing Myocardium.

To improve long-term outcome after cryoablation of substrates of supraventricular tachycardia, application of two and three consecutive freeze-thaw cycles has been performed. The effect of triple freeze-thaw cycles on lesion formation within developing myocardium and coronary arteries, however, has not been studied yet. In eight piglets (mean age 15 weeks, weight 15-20 kg), 30 cryolesions (three consecutive freeze-thaw cycles) were applied to the atrial aspect of both AV valve annuli (n = 18) as well as to ventricular myocardium below the valves (n = 12). Coronary angiography was performed before and after cryoenergy application. The animals were reevaluated by coronary angiography and intracoronary ultrasound (ICUS) after 48 h. All hearts were removed for histological examination of the lesions subsequently. After staining (hematoxylin-eosin, desmin immunohistochemistry), lesions was measured by planimetry with a digital virtual miscroscope analysis system and volumes of the cryolesions were calculated. Mean atrial lesion volume was 190.68 ± 167.53 mm3 (n = 18), and mean ventricular lesion volume was 184.34 ± 107.42 mm3 (n = 12). Compared with previously reported data on lesion volumes after single and double freeze-thaw cycles, lesions were significantly larger. Coronary arteries were unaffected on coronary angiography as well as on ICUS. No affection of coronary arteries was found on histological examination. Application of three consecutive freeze-thaw cycles resulted in increased lesion volume compared with single and double freeze-thaw cycles. No affection of the coronary arteries was evident. To evaluate the clinical benefit and safety of triple cryoenergy application for catheter ablation, prospective randomized trials are required.

Immobilization of chlorophyll by using layer-by-layer technique for controlled release systems and photodynamic inactivation.

The development of systems for the controlled release of drugs is important because they allow the control of drug absorption and tissue distribution and also can reduce local toxicity. This study aimed to assemble and characterize two types of release systems, consisting of layer-by-layer films obtained from poly(allylamine) hydrochloride with chlorophyll (PAH/CHL films) or chlorophyll incorporated into dipalmitoylphosphatidylcholine liposomes (PAH/Lip+CHL films). For these systems, the molecular aggregation, growth process, thermally stimulated desorption, wettability, and controlling release of CHL was studied by using UV-vis spectroscopy and wetting contact angle analysis. In addition, experiments of photodynamic inactivation using PAH/CHL or PAH/Lip+CHL films with a 633-nm laser light were performed and the susceptibility of Candida albicans (C. albicans) to this approach was examined. Fluorescence and atomic force microscopies were used to investigate the surface morphology after the application of the photoinactivation procedure. A redshift of the UV-vis spectrum associated to films when compared with the spectrum of the CHL solution indicated a molecular aggregation of CHL molecules in the films. The film growth process was determined by a nucleation and a growth of spheroids or rods for either PAH/Lip+CHL or PAH/CHL films, respectively. Thermally activated desorption experiments indicated that interactions between CHL and PAH (126kJ/mol) in PAH/CHL or between Lip+CHL and PAH (140kJ/mol) in PAH/Lip+CHL films may be governed by electrostatic interactions. The wettability of PAH/Lip+CHL films was larger than that for PAH/CHL films, which can be attributed to hydrophilic groups on the surface of the DPPC liposomes. Release experiments revealed that free CHL in PAH/CHL films was released more slowly than its partner incorporated into liposomes. After the photodynamic inactivation, results of survival fraction and fluorescence microscopy revealed that C. albicans presented similar susceptibility for the two kinds of films. AFM supported the fluorescence one suggesting that cell death of C. albicans may occur due to damages to its cell wall by C. albicans.

The effect of acid-base clustering and ions on the growth of atmospheric nano-particles.

The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.

Morphological analysis and interaction of chlorophyll and BSA.

Interactions between proteins and drugs, which can lead to formation of stable drug-protein complexes, have important implications on several processes related to human health. These interactions can affect, for instance, free concentration, biological activity, and metabolism of the drugs in the blood stream. Here, we report on the UV-Visible spectroscopic investigation on the interaction of bovine serum albumin (BSA) with chlorophyll (Chl) in aqueous solution under physiological conditions. Binding constants at different temperatures--obtained by using the Benesi-Hildebrand equation--were found to be of the same order of magnitude (~10(4)M(-1)) indicating low affinity of Chl with BSA. We have found a hyperchromism, which suggested an interaction between BSA and Chl occurring through conformational changes of BSA caused by exposition of tryptophan to solvent. Films from BSA and Chl obtained at different Chl concentrations showed fractal structures, which were characterized by fractal dimension calculated from microscopic image analysis.

Oxidation products of biogenic emissions contribute to nucleation of atmospheric particles.

Atmospheric new-particle formation affects climate and is one of the least understood atmospheric aerosol processes. The complexity and variability of the atmosphere has hindered elucidation of the fundamental mechanism of new-particle formation from gaseous precursors. We show, in experiments performed with the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN, that sulfuric acid and oxidized organic vapors at atmospheric concentrations reproduce particle nucleation rates observed in the lower atmosphere. The experiments reveal a nucleation mechanism involving the formation of clusters containing sulfuric acid and oxidized organic molecules from the very first step. Inclusion of this mechanism in a global aerosol model yields a photochemically and biologically driven seasonal cycle of particle concentrations in the continental boundary layer, in good agreement with observations.