Lower Values Research Articles

Valorization of Coffea arabica Wood Waste to Obtain Suspensions of Lignocellulose Microfibrils and Lignocellulose Nanofibrils (LCMF/LCNF) and Production of Eco-Friendly Films for Packaging

Coffee is one of the most consumed commodities globally, and its harvests generate large quantities of wood waste with low industrial value. This study aimed to explore the potential of residual Coffea arabica wood to produce lignocellulose microfibrils and lignocellulose nanofibrils (LCMF/LCNF) and biodegradable films with possible application in packaging. The fibers were treated with 5% NaOH and fibrillated in an ultrarefiner until they formed a gel. The resulting suspensions were used to create films whose physical, morphological, optical, and mechanical properties were analyzed. The NaOH treatment removed extractives and exposed hemicelluloses, allowing the gel point to be reached with just seven passes through the ultrarefiner, saving energy (~4700 kWh/t). More than 65% of the fibers had diameters of less than 100 nm and little sedimentation after 8 h. The films were flexible, thin (24.5 µm), with a high density (~1100 kg/m3) and good resistance to grease, as well as a water vapor permeability of ~1230 g/m2/day, suitable for packaging bread, fruit, and vegetables. However, the higher wettability of the surface may limit its use in humid environments. The films showed moderate tensile strength (~25 MPa) but low puncture resistance (~7 N mm), making them suitable for biodegradable packaging.

Reliability and Educational Suitability of TikTok Videos asa Source of Information on Sleep and Awake Bruxism: ACross-Sectional Analysis.

TikTok contains many videos about bruxism that may help raise the level of awareness on the topic. However, the quality of these videos' information represents the greatest concern. The present cross-sectional analysis aimed to systematically assess the reliability and educational suitability of TikTok videos as a source of information on bruxism. TikTok was searched for relevant videos uploaded until 6 March 2024, using the hashtags #bruxism, #grindingteeth and #jawclenching. Independent pre-calibrated operators conducted video inclusion and data collection, noting videos' characteristics, source, popularity, content, reliability (assessed through the DISCERN scoring system) and educational value (assessed through the Global Quality Score [GQS]). The Kruskal-Wallis test was adopted to compare videos from different sources. Videos with low and high educational value were compared using the Mann-Whitney U-test. Tests were considered significant when the p-value was < 0.05. A total of 105 bruxism videos were analysed. Most videos covered bruxism management and clinical features, and more than 60% were uploaded by healthcare professionals. According to the DISCERN and GQS scoring, the videos' reliability and educational value were judged to be very poor and low, respectively, but on average they were higher for videos uploaded by healthcare professionals compared to those uploaded by laypeople. When comparing videos with high educational value to those with low educational value, differences were found in popularity, content and reliability. The present results suggest the need for greater control of information disseminated on social media to fulfil its potential role in educating laypeople about bruxism.

Assessment of amino acids and metabolites in the supernatant of stored concentrates blood from sickle cell trait (SCT) and reference (non-SCT) donors.

Sickle cell trait (SCT) persons are significant donors, and discarding these blood units reduces their supplies, mainly in the third-world countries. This work focused on 12 metabolites associated with the red blood cell (RBC) storage lesion and 23 amino acids in the supernatants of packed RBC units from SCT and reference (non-SCT) donors stored in the same conditions. All samples of RBC concentrates were collected and separated from the storage of Colsan (Beneficient Association of Blood Collection), where they were routinely processed and separated as packed RBC units and stored in the refrigerator (2°-6°C). The supernatant samples of each packed RBC bag were separated by centrifugation at days 1, 7, 14, 21, 28 and 35 of storage and kept at -80°C till the metabolite analysis together. The quantitation of metabolites and amino acids examined in the supernatant of SCT and reference donors showed no statistical differences along the cold storage. Lactic acid and malic acid releases occur in three phases during RBC storage. Basic and acid amino acids and corresponding amides have low and stable values during the first 14 days of storage, followed by a steep increase. Our metabolomic results give elements that seem not to contraindicate the transfusion of RBC with SCT, besides its more structural fragility.

Public health emergencies and international trade in the context of global value chains: Evidence from COVID‐19 in China

AbstractIn recent years, there has been a notable increase in the frequency of public health emergencies (PHE), which pose a substantial threat to the global supply and demand equilibrium as well as the stability of the global value chains (GVC). The article takes the example of the COVID‐19 pandemic and utilises China's foreign trade monthly data spanning from 2018 to 2021 for an empirical analysis of how COVID‐19 affected China's import and export trade, as well as its participation in GVC collaborations. The findings are as follows: (1) The proliferation of COVID‐19 significantly and negatively impacted China's export trade, while its impact on China's import trade was insignificant. (2) The impact of the COVID‐19 on processing trade exports was more pronounced compared to general trade exports, highlighting the detrimental effect of the pandemic on GVC collaboration. (3) The adverse influence of the COVID‐19 on China's foreign trade and GVC cooperation primarily stemmed from its impact on international effective demand. (4) The pandemic exerted a more substantial negative effect on processing trade involving supplied materials with low production value added compared to processing trade involving imported materials with high value added. And it had a greater adverse impact on low‐tech products as opposed to high‐tech products, indicating that industries with higher value‐added and high‐tech products exhibited greater resilience in the face of trade disruptions by COVID‐19.

Quantifying and Zoning Ecological Compensation for Cultivated Land in Intensive Agricultural Areas: A Case Study in Henan Province, China

Cultivated land ecological compensation (CLEC) is an important way to solve regional development imbalance and cultivated land problems, and the scientific quantification of the ecological value of cultivated land is the key to CLEC. This study quantified the total amount and urgency of CLEC in China’s main grain-producing region using the cropland ecological footprint (EF) and ecosystem service value (ESV) methods. Furthermore, this study analyzed the comprehensive zoning of CLEC considering natural and economic development. The results showed that the spatial distribution of EFs and the ecological carrying capacity of cultivated land in Henan Province are similar, presenting the spatial characteristics of being high in the southeast and low in the northwest; the cultivated land in most of the counties and districts is in a state of ecological surplus, and the cultivated land resources are sufficient to support their own consumption needs. Henan Province as a whole is an ecologically compensated region, with a compensation amount of CNY 1.39 billion, and the total amount of compensation is in a positive value of 94.94%. The Southwest Yu and North Yu economic zone of Henan are the areas of high and low values of cultivated land compensation. The priority compensation region is the most extensive and widely distributed type in the five regions of Henan Province, accounting for 55% of the counties and districts. The degree of compensation is most urgent in the Huanghuai, Southwest Yu, and North Yu economic zones. This study’s findings provide new ideas for the development of differentiated ecological compensation policies, and provide references for the participation of multiple market participants and the diversification of compensation forms.

Optical and Amplified Spontaneous Emission Properties of 4H-Pyran-4-Ylidene-2-Cyanoacetate Fragment Containing 2-Cyanoacetic Acid Derivative in PVK, PSU, or PS Matrix

Organic solid-state lasers are highly promising devices known for their low-cost fabrication processes and compact sizes and the tunability of their emission spectrum. These lasers are in high demand across various industries including biomedicine, sensors, communications, spectroscopy, and military applications. A key requirement for light-emitting materials used in a light-amplifying medium is a low threshold value of the excitation energy of the amplified spontaneous emission (ASE). A newly synthesized non-symmetric red-light-emitting laser dye, Ethyl 2-(2-(4-(bis(2-(trityloxy)ethyl)amino)styryl)-6-tert butyl-4H-pyran-4-ylidene)-2-cyanoacetate (KTB), has shown great promise in meeting this requirement. KTB, with its attached bulky trityloxyethyl groups, has the ability to form amorphous thin films from a solution using a wet-casting method. Recent experiments have demonstrated that KTB exhibits a low ASE threshold value. This study focused on investigating the optical and amplified spontaneous emission properties of KTB in poly(N-vinylcarbazole) (PVK), polysulfone (PSU), and polystyrene (PS) matrices at various concentrations. The results showed that as the concentration of the dye increased, a redshift of the photoluminescence and ASE spectra occurred due to the solid-state solvation effect. The lowest ASE threshold value of 9 µJ/cm2 was achieved with a 20 wt% concentration of KTB in a PVK matrix, making it one of the lowest excitation threshold energies reported to date.

Serum 25 Hydroxy – D in Patients without Vitamin D Supplementation: Perspectives from Cohorts with Rheumatoid Arthritis and Systemic Lupus Erythematosus

Hypovitaminosis D is common in the sunny UAE. This study focusses on the perspectives of 25 hydroxy-D in patients with RA and others with SLE ((Autoimmune disease, ADs)) and to compare them to others of patients without ADs) .The latter were used as control group. All included individuals were without history of vitamin D intake. Hypovitaminosis D was common in the 3 groups (RA, SLE and controls). However, the prevalence of hypovitaminosis D in patients with each of ADs was significantly lower to that of the control group yet with higher means of 25 (OH) D levels. These findings were in contrast to those of number of regional and international studies conducted earlier. Data on the high prevalence of hypovitaminosis D and the low mean values of 25 (OH) D were comparable between the two groups of ADs. Overall, the results of this study may lead to some controversy or perhaps a challenge to the widespread understanding of the contrary as per previous international and regional studies. They also argue further the concept of specific association of hypovitaminosis D and autoimmune disease and certainly encourage wider estimation of 25(OH) D among larger numbers of patients in general medical practice. Finally, the outcomes of this work deserve further study/ies in larger groups in the future.

Perfusion index as an early predictor of hypotension during advanced oncothoracic operations (pilot study)

Introduction. Current standards of intraoperative monitoring significantly reduce the response time to a decrease in blood pressure, but do not include methods for predicting changes in hemodynamics to avoid the effects of systemic hypoperfusion.The objective was to evaluate the usefulness of determining the perfusion index for predicting the development of hypotension and its earlier correction during advanced oncothoracic operations.Materials and methods. A prospective open-label observational study was conducted, which included 100 patients who underwent elective oncothoracic surgery. Standard monitoring was established, as well as continuous monitoring of the perfusion index. The perfusion index value was recorded immediately before induction. The patients were divided into 2 groups: in the 1st group (n = 37), patients experienced a decrease in blood pressure, requiring vasopressor support; in the 2nd group (n = 63), no vasopressor support was required.Results. A moderate linear relationship was revealed with a correlation coefficient (r) equal to (–0.68), p &lt; 0.001, and a strong non-linear relationship with a coefficient (ρ) equal to (–0.95), p &lt; 0.001. To identify the relationship model, polynomial regression analysis was performed. A prognostic formula for the use of vasopressors was calculated depending on the preoperative level of perfusion index. At the next stage, a classification tree for analyzing the data array was used. The entire d data array (n = 100) is randomly divided into training (n = 70) and test samples (n = 30). It was revealed that hypotension requiring vasopressor support occurred in patients whose initial perfusion index was ≤ 2.85. ROC analysis determined an AUC of 0.952 (95% CI: 0.888–1.016).Conclusion. A low PI value before induction of anesthesia during advanced oncothoracic operations can be used to monitor the functional activity of the autonomic nervous system and predict intraoperative hypotension. Patients with a baseline PI ≤ 2.85 have a higher risk of developing hypotension during advanced oncothoracic surgery compared with those with a baseline PI ≥ 2.85. The effectiveness of the method in patients with concomitant pathologies has not been tested.

Assessing the influence of thermal structure variation on Fe and P mobility in sediments cores using Yellow Spring Instrument, diffusive gradient technology, and HR Peeper for sustainable water quality management.

The freshwater ecological characteristics in terms of the daily inventory of thermal stratification, spatial variation of O2 distribution, and the mobility of potentially toxic elements (PTEs) at the water sediment interface (WSI) are prudent freshwater assessment indices for water quality management protocol. The study conducted daily observations within a monsoon-influenced region, utilizing high-resolution techniques such as HR Peeper, Yellow Spring Instrument (YSI), and ZrO-Chelex diffusive gradient technology (DGT) to analyze PTEs, specifically phosphorus (P) and iron (Fe),within the water-sediment interface (WSI) under different temperatures and oxygen conditions. The 66-day field study showed that high thermal structure contributed significantly to production Fe ions and P from sediment under reductive dissolution of FeOOH. The study also revealed that P and Fe exhibited comparable spatial distribution patterns at the WSI, indicating a linked relationship between these PTEs. This correlation was reinforced by high Pearson correlation coefficients ranging from 0.7 to 0.9 (bilateral, p < 0.05) indicating that the concentrations of labile P were predominantly influenced by the release of phosphorus bound to iron. The fluxes of the PTEs were positive with a range of Fe, 3.3-81.5 mg/m2 day and P, 0.03-0.5 mg/m2 day showing the sediments liberated the PTEs into the benthic water. Again, high positive fluxes (Fe≈60 mg/m2 day, P≈0.5 mg/m2 day) for PTEs were obtained when stratification was high (anoxic conditions) and low (Fe≈5 mg/m2 day, P≈0.08 mg/m2 day) when stratification did not exist. This depicts that Fe/P dynamics were hinged mainly on hypoxic conditions in the benthic water under the reductive dissolution of FeOOH. The findings showed that organic materials (both solid and dissolved) correlated (> 0.7) significantly with (positive high values) Fe. This indicates that their interaction contributed to the reservoir water deterioration. However, Ca2⁺ and Mg2⁺ had little impact on the liberation of Fe-DOC-P from sediments due to their inability to compete with Fe for binding to DOC and P, as shown by their low correlation values. The research provides in-depth insights into the dynamics of PTEs on a daily timescale and offers valuable information for water management practices in inland reservoirs, particularly concerning the cycling of phosphorus (P) and its effects on ecosystem health.

The effective elastic thickness along the Emperor Seamount Chain and its tectonic implications

Summary The Hawaiian-Emperor Seamount Chain, a pre-eminent example of a hotspot-generated intraplate seamount chain, provides key constraints not only on the kinematics of plates but also on their rigidity. Previous studies have shown that the effective elastic thickness, Te, a proxy for the long-term strength of the lithosphere, changes abruptly at the Hawaiian-Emperor ‘bend’ from low values (∼16 km) at the Emperor Seamounts to high values (∼27 km) at the Hawaiian Ridge. To better constrain Te along the poorly explored Emperor Seamounts we have used a free-air gravity anomaly and bathymetry gridded data set, together with fully 3-dimensional elastic plate (flexure) models, to estimate the continuity of Te and volcano load and infill densities along 1000 profiles spaced 2 km apart of the chain. Results show that Te generally decreases northward along the chain. The decrease is most systematic between Ojin and Jimmu guyots where Te depends on the age of the lithosphere at the time of volcano loading and is controlled by the 340°C and 400°C oceanic isotherms. The largest variation from these isotherms occurs at the northern and southern ends of the chain where Te is smaller than expected suggesting the influence of pre-existing, older, loads. We use these results to constrain the subsidence, flexural tilt, rheological properties, and tectonic setting along the seamount chain. We found an excess subsidence in the range 1.2-2.4 km, a tilt as large as 2-3°, oceanic lithosphere that is weaker than it is seaward of the weak zone at subduction zones, and a tectonic setting at Detroit and Koko seamounts that, despite their forming an integral part of the hotspot generated seamount chain, retains a memory of their proximity to earlier loads associated with plume influenced mid-oceanic ridges.

Folic acid-targeted redox responsive polylactic acid-based nanoparticles co-delivering pirarubicin and salinomycin suppress breast cancer tumor growth in vivo.

Targeted cancer therapy using nanocarriers has emerged as a promising solution to the majority of drawbacks associated with conventional chemotherapy. The present research work describes the development of folic acid (FA)-targeted redox responsive [S-(PLA-b-PEG-CONH)]2 polymeric nanoparticles for the co-delivery of pirarubicin (Pira) and salinomycin (Sal). The nanoparticles' redox responsiveness arises from embedded disulfide bonds within the polymer, which gradually break in response to high GSH levels in tumors, enabling sustained drug release. The nanoparticles exhibited a hydrodynamic size of ∼104 nm and a surface charge density of -15.5 mV with low PDI values. Blank nanoparticles (w/o drug) showed negligible toxicity towards both non-malignant human and murine cells and exhibited excellent stability under different environmental conditions for up to 3 weeks. A cellular internalization study conducted using Rho B/C6 dual-dye-encapsulated nanoparticles showed efficient uptake of the nanoparticles after just 1 hour of incubation with SUM-149 2D adherent cells and 3D spheroids. The release of Pira and Sal from Pira/Sal dual-loaded nanoparticles increased significantly in a reducing environment. The % cumulative release of Pira increased from 20.5% ± 1.0 in PBS (pH 7.4) to 40.1% ± 0.4 in dithiothreitol (DTT) after 20 days; similarly, the % cumulative release of Sal increased from 36.2% ± 1.7 in PBS (pH 7.4) to 51.5% ± 1.7 in DTT. The cytotoxicity studies of FA-targeted Pira/Sal dual-loaded nanoparticles with varying Pira : Sal ratios (1 : 1, 3 : 1 and 1 : 3) revealed that the nanoparticles displayed 8-10 fold lower IC50 values than the respective free drug formulations across multiple breast cancer cell lines including SUM-149, MDA-MB-231 and EAC as well as in 3D mammospheres. Balb/c syngeneic mice bearing EAC tumors experienced ∼100% tumor regression upon treatment with FA-targeted Pira/Sal (3 : 1) dual-loaded nanoparticles, indicating synergistic anti-tumor potency. In vivo survival and histopathological studies indicated no significant toxicity in vital organs of the body as compared to free drugs. Based on the performance, the currently investigated FA-targeted Pira/Sal dual-loaded nano-formulation is recommended to be further explored in other cancer types as well as in higher animals for cancer therapy.

Genetic Diversity of Yellow and Red Berries Arabica Coffee Populations Grown in a Mix Populations in Garut, West Java, Indonesia, Based on SSR Markers

Farmers in Garut, West Java, grow mixed varieties of Arabica coffee (Coffea arabica L.). Subsequently, they use harvested beans as seeds. Intercrossing among varieties may result in hybrid progenies and harvesting hybrid progenies as seed results in genetic variations. This research aims to evaluate the genetic diversity of Arabica coffee grown in a mixed population. Ninety-one Arabica coffees comprised 37 Arabica cv. “Ahernt GRT KN” (yellow-), 45 “Sigararutang” (red-), and nine “S795” (red berries) were sampled. Twenty SSR primer pairs were validated using 15 samples representing three varieties; six were polymorphic and used to genotype 91 Arabica accessions. Genetic data were analyzed using PowerMaker 3.25 and Darwin version 6 software. The results showed that the six SSR loci generated from 2 – 3 alleles, with an average of 2.17 alleles per locus. Genetic analysis of Arabica coffee from Garut, West Java, generated SSR markers with an average PIC of 0,33 across loci and varieties. The PIC within Arabica coffee cv. “Ahernt GRT KN” and “Sigararutang” were low, and within “S795” was moderate. Those PICs indicate the presence of more genetic diversity within “S795” than the other two cultivars. The Ho across Arabica coffee cv. “Sigararutang” and “S795” were lower than the He values, confirming their self-pollination nature. However, the Ho values of Arabica coffee cv. “Ahernt GRT KN” was larger than the others, indicating the presence of residual heterozygosity and a low percentage of recent outcrossing. The low Ho values of “Sigararutang” suggest that Arabica coffee is homozygous. Arabica coffee cv. “S795” also showed a low Ho value, but its moderate He value indicates the presence of more genetic diversity than the othercultivars.

Low Sintering Temperature Effect on Crystal Structure and Dielectric Properties of Lead-Free Piezoelectric Bi0.5Na0.5TiO3-NaFeTiO4

Bi0.5Na0.5TiO3 (BNT) emerges as a promising ferroelectric and piezoelectric lead-free candidate to substitute the contaminant Pb[TixZr1−x]O3 (PZT). However, to obtain optimal ferroelectric and piezoelectric properties, BNT must be sintered at high temperatures. In this work, the reduction of sintering temperature by using iron added to BNT is demonstrated, without significant detriment to the dielectric properties. BNT-xFe with iron from x = 0 to 0.1 mol (∆x = 0.025) were synthesized using high-energy ball milling followed by sintering at 900 °C. XRD analysis confirmed the presence of rhombohedral BNT together with a new phase of NaFeTiO4 (NFT), which was also corroborated using optical and electronic microscopy. The relative permittivity, in the range of 400 to 500 across all the frequencies, demonstrated the stabilization effect of the iron in BNT. Additionally, the presence of iron elevates the transition from ferroelectric to paraelectric structure, increasing it from 330 °C in the iron-free sample to 370 °C in the sample with the maximum iron concentration (0.1 mol). The dielectric losses maintain constant values lower than 0.1. In this case, low dielectric loss values are ideal for ferroelectric and piezoelectric materials, as they ensure minimal energy dissipation. Likewise, the electrical conductivity maintains a semiconductor behavior across a range of 50 Hz to 1 × 106 Hz, indicating the potential of these materials for applications at different frequencies. Additionally, the piezoelectric constant (d33) values decrease slightly when low concentrations of iron are added, maintaining values between 30 and 48 pC/N for BNT-0.025Fe and BNT-0.05Fe, respectively.

Clinical Factors Associated with Suspicious 18F-DCFPyL PSMA PET Activity in Patients Initially Managed with Radical Prostatectomy including PSA

There is limited data on PSMA PET/CT for work-up of recurrence after radical prostatectomy (RP) at low PSA values. We evaluated a PSMA PET/CT cohort of post-RP patients, focusing on patients with PSA <0.5 ng/mL. We identified a retrospective cohort who underwent piflufolastat F-18 PSMA PET/CT across an eleven-hospital system from 7/2021-2/2023. PSMA positivity was determined by radiology reports. Univariable and multivariable logistic regression identified factors associated with suspicious PSMA activity. Median PSA was 0.37 ng/mL (IQR 0.15, 1.29 ng/mL), with 49% of patients overall having at least one suspicious PSMA-avid lesion. Rates of scan positivity among patients with PSA <0.2 and 0.2-0.5 ng/mL were 34% and 38%, respectively. Among all patients, 25% (104/415) had pelvic disease (prostate bed or N1), and 24% (100/415) had M1 disease. Among patients with PSA <0.5 ng/mL, prior post-operative radiation was associated with suspicious PSMA activity. In the overall cohort, age, PSA at PSMA PET/CT, and RP Gleason Grade (GG) were associated with PSMA positivity. PSADT, EAU risk, and CAPRA-S were all associated with suspicious PSMA activity. Over one-third of patients with PSAs <0.2 ng/mL had imaging findings concerning for recurrence. Prior post-operative radiation was associated with higher rates of PSMA positivity among patients with PSA <0.5 ng/mL, and half of patients with evidence of PSMA avid distant metastatic disease underwent metastasis directed therapy. PET-PSMA imaging at low PSAs can be considered to inform salvage therapies.

A review of the global use of fishmeal and fish oil and the Fish In:Fish Out metric.

Aquacultured carnivorous species consume most of the world's fishmeal and fish oil (FMFO), which itself is primarily derived from small pelagic fish. This has raised concerns about the practice's impact on wild fish stocks, ecosystems, and coastal communities that rely on these fish. The aquaculture industry claims a decreasing dependence on wild fish, relying on the Fish In:Fish Out (FIFO) metric as a ratio of the quantity of wild fish required for farmed fish production. This is misleading because it usually assumes constant FM or FO yields, inclusion rates and feed conversion ratios, which vary widely. Thus, a constant FIFO value for a given species cannot be assumed. Furthermore, low FIFO values resulting from averaging carnivores and herbivores conceal the high feed requirements of carnivore species. The increasing use of FMFO from by-products does not demonstrate a decreased use of wild fish but rather reflects a growing demand for FMFO, particularly for the fast growing and valuable salmon and shrimp farming industries.

Public information dissemination and its impact on force account implementation in Kalambo district council, Tanzania

The study assessed dissemination of public information and its impact on implementation of force accounts in Kalambo District Council in Tanzania. A cross-sectional design was employed in collecting data at one point in time with a mixed methods research approach which was used in an attempt to gain detailed information. A total of 145 participants which includes ward development committees, construction committees and community members were involved whereby 46 key informants were selected purposely based on their positions while simple random sampling technique was used in selecting 99 respondents from the community. The survey, interview, focus group discussion and documentary review method were used to gather both quantitative and qualitative data. Quantitative data were analysed using descriptive statistical analysis whereas qualitative data were analysed using content analysis. The study findings revealed that information is not easily accessible to the public and a few shared information is not clear due to confidentiality and technical language. The findings also indicate that the public is unaware about the progress force account due to ineffective dissemination of information which leads to untimely completion of works and misuse of resources. The study concludes that there is inadequate information in the implementation of force account projects, thus resulting in poor support, acceleration of low value for money and lack of accountability due to poor public scrutiny. The study recommends that the government institutions should emphasise the use of authorised social and religious gathering in an attempt to raise awareness. Moreover, the selected committee must engage the public in decision making in order to improve transparency in implementation of projects.

Physical fitness as a factor in the effectiveness of the competitive activity of 17-18-year-old football players during the transition to professional teams

The need to demonstrate high results, on which a coach's career depends, forces the latter to practically ignore the psychophysiological features of the body of athletes aged 17-21 during the educational and training process and measures to restore players after exertion. As a result, the demands of professional football for most of the talented youth become excessive, which leads to overfatigue and a high level of injuries. The most rational approach to solving the problem of training football players during the transition to professional teams should be based on a systematic training methodology that will ensure effective development of sportsmanship, systematic growth of functional capabilities and their proper implementation. It should be noted that the indicators of physical and technical fitness of football players after graduating from the children's and youth football school do not meet the requirements of professional football. The article is devoted to solving the problem of the effectiveness of the competitive activity of 17-18-year-old football players during the transition to professional teams. The work revealed that the age range from 17 to 21 years falls on the period of an athlete's life, when the formation of all functional systems, which ensure high performance and immunity of the body against adverse factors that appear during intense training, is basically completed. It was noted that the physical and technical fitness indicators of football players after graduating from the children's and youth football school do not meet the requirements of professional football. The peculiarities of physical fitness in relation to the effective competitive activity of 17-18-year-old football players at the stage of specialized basic training were analyzed. The data of the study served as indicators of the players' physical fitness. As a result of the conducted correlational analysis of the physical fitness of young football players aged 17-18 years, an average and low value of the relationship was determined, which implies a fairly close relationship between the level of physical fitness and almost all indicators of the sportsmen's motor qualities, except for the indicator that characterizes the starting speed. It has been confirmed that the preparedness of athletes in football depends on their functional indicators, which, in turn, determine the effectiveness of certain tactical and technical actions.

Structure and properties of mixed valent CeFe2Al8

Temperature dependent magnetic, electrical transport and thermal properties of polycrystalline orthorhombic CeFe2Al8intermetallic compound have been studied along with its isostructural La counterpart, LaFe2Al8. For the cerium compound, low fielddcmagnetization exhibits an antiferromagnetic like ordering (TN) ∼ 4 K. The main feature of the magnetic susceptibility plot is a broad hump spanning a large temperature range, indicating mixed valence of Ce in the compound, in good agreement with reported literature. However, contrary to the reported observations we find that the mixed valence state is very robust and was evident even up to very high magnetic fields (> 2 T). Further, in this work we report 3d core level photoemission spectra of cerium in CeFe2Al8, to understand the valence state of cerium ions in this system. Additionally, from resistivity measurements it is found that, CeFe2Al8is metallic with no indication of any anomaly, till the lowest temperature of measurement. Specific heat measurements show very low value of heat capacity and electronic contribution. The isostructural La analogue, LaFe2Al8compound shows broadness in susceptibility with maxima around 44 K which may be attributed to ordering of Fe moments. The comparison of Ce and La compounds brings out the role of Fe magnetic moments which may be responsible for competing with cerium moments and resulting in the dilution of long-range magnetic order, also contributing to magnetic frustration in CeFe2Al8.

Ideology at Work? Rethinking Reproduction

The low value of reproductive labor, and the related “crisis of care,” are often attributed to gendered attitudes about work. This article traces this explanation to the attempted synthesis of Marxist and feminist theories of ideology in the 1970s and offers a sympathetic critique with implications for both contemporary theories of labor and the “new ideology critique.” It reconstructs the explanatory role of ideology in feminist analyses of unwaged housework and tracks its uptake in theories of “reproductive labor” more broadly, via what I call the “naturalization thesis.” While these analyses have been influential, I show that they do not provide a convincing account of either gender oppression or the low value of reproductive labor. I offer an alternative explanation for the latter rooted in labor processes and patterns of capital accumulation and argue for the reintegration of ideology critique with the critique of political economy.

Properties of Sn-Doped PBZT Ferroelectric Ceramics Sintered by Hot-Pressing Method.

This work investigated the structure, microstructure, and ferroelectric and dielectric behavior of (Pb0.97Ba0.03)(Zr0.98Ti0.02)1-xSnxO3 (PBZT_xSn) solid solution with variable tin content in the range x = 0.00-0.08. Synthesis was carried out using the powder calcination method, and sintering was carried out using the hot-pressing method. For all the PBZT_xSn samples at room temperature, X-ray diffractograms confirmed the presence of an orthorhombic (OR) crystal structure with space group Pnnm, and the microstructure is characterized by densely packed and properly shaped grains with an average size of 1.36 µm to 1.73 µm. At room temperature, PBZT_xSn materials have low permittivity values ε' ranging from 265 to 275, whereas, at the ferroelectric-paraelectric phase transition temperature (RE-C), the permittivity is high (from 8923 to 12,141). The increase in the tin dopant in PBZT_xSn lowers permittivity and dielectric loss and changes the scope of occurrence of phase transitions. The occurring dispersion of the dielectric constant and dielectric loss at low frequencies, related to the Maxwell-Wagner behavior, decreases with increasing tin content in the composition of PBZT_xSn. Temperature studies of the dielectric and ferroelectric properties revealed anomalies related to the phase transitions occurring in the PBZT_xSn material. With increasing temperature in PBZT_xSn, phase transitions occur from orthorhombic (OR) to rhombohedral (RE) and cubic (C). The cooling cycle shifts the temperatures of the phase transitions towards lower temperatures. The test results were confirmed by XRD Rietveld analysis at different temperatures. The beneficial dielectric and ferroelectric properties suggest that the PBZT_xSn materials are suitable for micromechatronic applications as pulse capacitors or actuator elements.