High Change Research Articles

Satellite-derived forest canopy greenness shows differential drought vulnerability of secondary forests compared to primary forests in Peru

Understanding tropical secondary forest canopy greenness and responses to climatic conditions is important for climate change mitigation, particularly in the tropics where secondary forest growth is a substantial carbon sink and a promoted natural climate solution. We here test three hypotheses: (a) forest canopy greenness is higher in younger, secondary forests than in older, primary or mature forests, (b) secondary forests are more vulnerable to climatic pressures and (c) there are significant differences between forest types regarding primary–secondary canopy greenness and their differential responses to drought anomalies. To explore these relationships, we monitored wet and dry seasonal greenness from 2001 to 2020, estimated through the enhanced vegetation index (EVI), of Peruvian tropical dry, montane and lowland secondary forests and compared it to nearby primary forests. We developed predictive models of seasonal EVI using remotely sensed variables, including land surface temperature (LST), evapotranspiration (ET), potential evapotranspiration (PET), ratio of ET and PET (ETn), and the standard precipitation index (SPI). Overall, there was a higher change in annual and seasonal EVI for secondary forests compared to primary forests. However, primary forests maintained relatively stable EVI levels during the wet season despite drought anomalies. When decoupling forest type canopy greenness and drought response, primary forest greenness in dry and lowland ecosystems were temporally more stable. Secondary montane had a lower increase in greenness when drought anomalies held during different seasons. Stepwise multiple linear regression models indicated that LST and ETn, a plant water use index, were the most significant factors to predict greening fluctuations in dry and montane forest types. ET and SPI mostly drove wet season mean EVI across all forest types. Predictors of dry season mean EVI varied, but mostly including water availability. Our results suggest that tropical secondary forests are more productive overall yet more vulnerable to prolonged drought.

The Impact of a Vegan Diet on Cardiovascular Disease Risk in Men and Women Through the Gut Microbiome

Studies highlight many benefits of a vegan diet on the composition of the gut microbiome, however little is known how and if these changes contribute to heart health. Trimethylamine (TMA) is a metabolic product produced from the breakdown of choline and L-Carnitine both found abundantly in red meat. TMA is converted to toxic trimethylamine N-oxide (TMAO) in the liver via flavin monooxygense 3 (FMO3). The objective of this study was to examine if vegan diets impact TMA levels thus supporting cardiovascular health. We hypothesize that a vegan diet will foster bacterial diversity that favors decreased TMA/TMAO levels. Zebrafish were initially placed on antibiotics to clear their microbiome, following treatment, fish were fed a control, high fat (HF), or vegan diet for 3 weeks. Fish were sacrificed and intestinal, liver and heart tissue were harvested for analysis. Surprisingly, we observed the most significant increase in bacterial abundance in the HF diets relative to the vegan and control diets (n= 5-6, p< 0.05). Interestingly, when separated by sex, the highest change in bacterial abundance was seen in female fish on a HF diet. We next examined mRNA levels of FMO3. We saw the greatest increase in FMO3 levels in female fish on a HF diet, which corresponds to higher bacterial abundance (n= 5-6, p< 0.05). FMO3 levels were also increased for fish on a HF diet relative to the control diet with no significant differences between male and female fish. These results indicate that vegan diets may alter male and female bacterial composition differently and the impacts of these differences on CV health remain unknown. Funding thus far has come from Elon University. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Optimizing Fine Motor Coordination, Selective Attention and Reaction Time in Children: Effect of Combined Accuracy Exercises and Visual Art Activities.

Optimizing fine motor coordination and cognitive abilities in middle childhood through new intervention programs remains one of the most essential orientations in motor development and skills proficiency. The present study aims to identify the effect of a structure-based program intervention, combining motor accuracy exercises with visual art activities (ceramics, pottery, and creations using raw materials), on fine motor coordination, selective attention, and reaction time in middle childhood. Sixty, right-handed typically developed male schoolchildren (age = 8.29 ± 0.74 years; body height = 130.25 ± 0.05 cm and body mass = 29.83 ± 4.68 kg; mean ± SD) volunteered to participate in the study. They were randomly assigned to a combined group intervention (MG) receiving a mixed program integrating visual art activities and motor accuracy exercises; an accuracy group intervention (AG) receiving oriented motor accuracy exercises; and a control group (CG). Selective attention, reaction time, and fine motor coordination skills (accuracy: darts throw; manual dexterity: grooved pegboard test) were measured. Repeated measure ANOVA, one-way ANOVA, and Kruskal-Wallis ANOVA were performed for analysis. The results showed higher changes in MG compared to AG in manual dexterity (p < 0.001), in motor accuracy (p < 0.001), and in reaction time (p < 0.01), but not in selective attention (p = 0.379). In addition, higher changes were recorded in AG compared to CG in motor accuracy (p < 0.05), reaction time (p < 0.05), and in selective attention (p < 0.01), but not in manual dexterity (p = 0.082). The structured combined program best assists accuracy, manual dexterity, reaction time, and selective attention. Therefore, instructors in sports academies and teachers at schools are advised to use the combined program in the training sessions and in the non-curricular activities, respectively, to improve fine motor coordination, selective attention, and reaction time in middle childhood.

Designing a Scenario-Based Fuzzy Model for Sustainable Closed-Loop Supply Chain Network considering Statistical Reliability: A New Hybrid Metaheuristic Algorithm

In this study, a new nonlinear mathematical programming model of mixed integer was presented to formulate the problem of designing a sustainable closed loop supply chain, in which the three aspects of sustainability, i.e., social effect such as job creation, customer satisfaction, and distributors, environmental effects such as reducing air pollution, and economic effects such as reducing supply chain costs, increasing supply chain reliability, quality of returned products by customers, and product routing were considered. In order to solve the proposed model, a new hybrid metaheuristic algorithm based on the distinctive features of gray wolf algorithm and genetic algorithm was proposed in addition to MOPSO and NSGA-II algorithms. After tuning their parameters by the Taguchi method, their performance in problems with different dimensions was tested and evaluated by MID, DM, and SM criteria. The results of statistical analysis of indices indicated that no significant difference between the performance of the three algorithms at 5% error level. In general, GW-NS, NSGA-II and MOPSO algorithms had better performance in terms of MID index, respectively. In addition, GW-NS, NSGA-II, and MOPSO algorithms performed better in terms of DM index. NSGA-II, MOPSO, and GW-NS algorithms performed better in terms of SM index, respectively. In addition, the variability of DM index in all three algorithms was almost the same, but in MID index, GW-NS algorithm, and in SM index, MOPSO algorithm had the highest change and less sustainability.

Spatio-temporal changes in urban water consumption during 2 years of the COVID-19 pandemic in southern Brazil

Abstract This study investigated the changes that occurred during the COVID-19 pandemic in urban water consumption in residential, commercial, industrial, and public agencies in the city of São Leopoldo, southern Brazil, which has about 55,000 consumers and over 200,000 inhabitants. Overall, the city increased water consumption by 5.6% during the 2-year pandemic, with 5.9% in 2020 and 5.5% in 2021. Residential and industrial consumption increased by 6.77 and 9.92% in the first year, and by 5.47 and 14.45% in the second year, respectively. On the other hand, commercial and public sector consumption decreased by 5.48 and 46.26% in the first year and 1.83 and 40.99% in the second year, respectively. In the first months of the pandemic, there was a sharp increase in residential water consumption at the same time as a reduction in consumption in the other categories. In contrast, there was a slight return to previous water consumption patterns in the following months. Overall, we can affirm that the more central neighborhoods presented higher changes in water consumption than the peripheral neighborhoods. In addition, the water consumption during the pandemic and pre-pandemic periods was statistically different for residential, industrial, and public consumers.

Coercive Force of Low-Carbon Steel Specimens Subjected to Cyclic Loading and Impulse Current

The change in the coercive force of the 10kp5 steel specimens subjected to cyclic loading and impulse current has been studied. The choice of processing methods, including their combination in a certain sequence, was shown to provide the best plastic or strength properties of metal materials. The feasibility and good perspectives of express assessment of the effectiveness of the chosen method or methods of processing metal materials by magnetic properties, e.g., coercive force, without resorting to mechanical tests with the destruction of specimens, are noted. The highest changes towards increase in strength and coercive force in the 10kp5 low-carbon steel have been found after cyclic loading and in a combined mode with cyclic loading at the final stage. The optimal combination of cyclic loading and pulse current can make it possible to control the strength and magnetic properties of ferromagnetic materials.

Sarcopenia-defining parameters, but not sarcopenia, are associated with cognitive domains in middle-aged and older European men.

Previous research suggests that sarcopenia is associated with lower cognitive functioning. Evidence on the longitudinal relationship between cognition and sarcopenia, according to the revised criteria of the European Working Group on Sarcopenia in Older People (EWGSOP2), is scarce. This study aimed to investigate both cross-sectional and longitudinal associations between sarcopenia and its defining parameters (muscle strength, muscle mass and physical performance) and cognitive performance in middle-aged and older men. This was a secondary analysis of data from the European Male Ageing Study (EMAS), a multicentre cohort study of men aged 40-79years, recruited from population registers in eight European centres. Cognitive functioning was assessed by using a battery of three neuropsychological tests, measuring fluid intelligence: Rey-Osterrieth Complex Figure (ROCF-Copy and ROCF-Recall), Camden Topographical Recognition Memory (CTRM) and Digit Symbol Substitution Test (DSST). Sarcopenia-defining parameters appendicular lean mass (aLM), gait speed (GS), chair stand test (CST) and handgrip strength (HGS) were measured. Sarcopenia was diagnosed according to the criteria of the EWGSOP2. All measurements were performed at baseline and after a follow-up of 4.3years. Cross-sectional associations between cognition, sarcopenia-defining parameters and prevalent sarcopenia (EWGSOP2) were analysed. Longitudinally, the predictive value of baseline cognition on decline in sarcopenia-defining parameters, onset of new sarcopenia and vice versa was examined. Linear and logistic regression were used and adjusted for putative confounders. In the whole cohort (n=3233), ROCF-Copy (β=0.016; P<0.05), ROCF-Recall (β=0.010; P<0.05), CTRM (β=0.015; P<0.05), DSST score (β=0.032; P<0.05) and fluid cognition (β=0.036; P<0.05) were significantly and independently associated with GS at baseline. In the Leuven+Manchester subcohorts (n=456), ROCF-Copy (β=1.008; P<0.05), ROCF-Recall (β=0.908; P<0.05) and fluid cognition (β=1.482; P<0.05) were associated with HGS. ROCF-Copy (β=0.394; P<0.05), ROCF-Recall (β=0.316; P<0.05), DSST (β=0.393; P<0.05) and fluid cognition (β=0.765; P<0.05) were associated with aLM. The prevalence of sarcopenia in this population was 17.8%. No associations were detected between cognition and prevalent or incident sarcopenia. Longitudinal analysis showed that low ROCF-Copy score at baseline was associated with an increase in CST in men ≥70years (β=-0.599; P<0.05). In addition, a decrease in ROCF-Recall was associated with a decrease in GS, and a decrease in DSST was associated with an increase in CST (β=0.155; P<0.0001, β=-0.595; P<0.001, respectively) in persons with the highest change in both cognition and muscle function. Sarcopenia was not associated with cognitive performance in this population, whereas several components of sarcopenia were associated with domain-specific cognitive performance. Longitudinally, baseline and change in subdomains of cognition predicted change in muscle function in specific subgroups.

An investigation on ultrasonic wave velocity of laminated sandstone under freeze-thaw and salt crystallization cycles: Insights from anisotropy effects

In this study, the anisotropy effects on the P (Vp) and S (Vs) wave velocities are investigated in laminated sandstone subjected to freeze-thaw (FT) and salt crystallization (SC) processes. For this purpose, cylindrical core specimens were prepared from sandstone at angles (β) of 0°, 30°, 45°, 60°, and 90° to the lamination direction. Next, FT and SC tests were performed up to 60 cycles. After every 10 cycles, the specimens’ Vp and Vs were determined at various β values. The decay constant (λ), half-life (N1/2), and rate of loss (RL) were used to investigate the anisotropy effects on the Vp and Vs of specimens under FT and SC and compare the effects of FT and SC on the Vp and Vs. The results indicated that anisotropy is an important factor in the durability of the specimens against FT and SC. In this respect, the specimens with β = 0° and β = 60° had the least and the highest changes in the Vp and Vs, respectively. Also, it was found that the anisotropic behavior of the specimens is different at various cycles of FT and SC such that it is intensified at higher cycles. Overall, it was concluded that SC had more significant effects on the Vp and Vs compared to FT. Considering the β values, the effect of a single cycle of the SC test in decreasing the Vp and Vs of the specimens corresponds to 1.34 to 1.94 and 1.28 to 1.70 cycles of the FT test, respectively.

Structural insights into the rare-earth modified La1.4-xSmxSr1.6Mn2O7 layered perovskites and probing their complex magnetic and magnetocaloric properties

In this work, structural characteristics upon rare-earth modification into the Ruddlesden-Popper (R-P) layered compounds La1.4-xSmxSr1.6Mn2O7 (0.00 ≤ x ≤ 0.20) were deeply investigated. The compounds were prepared through conventional ceramic-sintering method. X-ray diffraction (XRD) and Raman spectra collectively disclosed a reduction in the unit cell dimensionality and emergence of structural distortions upon Sm-modification which facilitated the separation of structural phases. Unlike the cubic manganites these distortions impart a chemical pressure mainly along c-axis of the tetragonal cell and favored a weak interbilayer exchange interaction native to layered lattice. The magnetization vs temperature (M-T) curves revealed multiple transitions that were chiefly attributed to such anisotropic exchange coupling and to a separate perovskite phase. The appearance of magnetic clusters was further confirmed in magnetization isotherms (M − H curves) and Arrott plots. The highest change in magnetic entropy (ΔSM) of 2.28 Jkg−1K−1 at 2.5 T field was obtained for pristine compound, the value slightly decreased to 1.78 Jkg−1K−1 for x = 0.05, and then increased up to 1.90 Jkg−1K−1 for x = 0.1 composition. Whereas the relative cooling power (RCP) abruptly enhanced to 100 J/kg, 110 J/kg and 92 J/kg for x = 0.05, 0.10 and x = 0.15 samples, respectively as compared to original value of 84 J/kg. It signifies an excellent magnetocaloric performance for x = 0.05 and 0.1 compositions over various categories of material systems and asserting the technological competence of these compounds for low temperature refrigeration applications.

Including genotypic information in genetic evaluations increases the accuracy of sheep breeding values.

The impact of inclusion of genome-wide genotypes into breeding value predictions for UK Texel sheep is addressed in this article. The main aim was to investigate the level of change in the accuracy values for EBVs when information from animal genotypes is incorporated into the genetic evaluations. New genetic parameters for a range of lamb growth, carcass composition and health traits are described and applied in the estimation of conventional breeding values (EBVs) for almost 822,000 animals as well as genomic breeding values (gEBVs) after adding 10,143 genotypes. Principal component analyses showed that there are no major distinct groups; hence, the population is mainly homogenous and genetically well-linked. Results suggested that the highest change in accuracy was observed for the animals that are not phenotyped but have good links to the reference population. This was seen especially for the lowly heritable health traits thereby proving that the use of genotypes in breeding values estimation may accelerate the genetic gain by producing more accurate values especially for young, un-phenotyped animals.

In vitro investigation of the impact of contemporary restorative materials on cariogenic bacteria counts and gene expression

ObjectivesThe aim of this study was to compare the antibacterial effect of different fluoride-containing and bioactive restorative materials, and their effect on the expression of specific biofilm-associated genes and therefore the caries process. Materials and methodsThe restorative materials utilized in this study included: 1. Filtek Z250, 2. Fuji II LC, 3. Beautifil II, 4. ACTIVA, and 5. Biodentine. For each material, disc-shaped specimens were prepared. The inhibitory effects against Streptococcus mutans, Lactobacillus acidophilus, and Leptotrichia shahii were tested. After incubation for 24 h and 1 week, colony-forming units (CFUs) were enumerated. From the plates dedicated for biomass quantification and RNA purification, the target glucosyltransferase B (gtfB) and glucan-binding protein B (gbpB) genes were chosen for S. mutans. For L. acidophilus, a gene involved in exopolysaccharide synthesis (epsB) was chosen. ResultsExcept for Filtek Z250, all four materials showed statistically significant inhibitory effects on the biofilms of all three species. When biofilms were grown in the presence of the same four materials, the expression of S. mutans gtfB and gbpB genes, was significantly reduced. For L. acidophilus, the decrease in the expression of gtfB gene in the presence of ACTIVA was the highest change seen. The epsB gene expression also decreased. Compared to fluoride-releasing materials, bioactive materials had more inhibitory effect against L. acidophilus, both at 24 h and 1 week. ConclusionsBoth fluoride releasing and bioactive materials exhibited a significant inhibitory effect on the biofilm growth. The expression of the targeted biofilm-associated genes was downregulated by both material groups. Clinical significanceThe findings from this study give insight into the antibacterial effect of fluoride-containing and bioactive materials which would help to reduce the chances for secondary caries and therefore increase the lifetime of dental restorations placed for patients.

Maximal Extension Interval and Visual Outcomes in a Treat-and-Extend Protocol: A Post Hoc Analysis of the CANTREAT Randomized Trial

Introduction: The Canadian Treat-and-Extend Analysis Trial with Ranibizumab (CANTREAT) was a 2-year, multicentred, randomized clinical trial to evaluate treat-and-extend (T&E) relative to monthly administration of ranibizumab in neovascular age-related macular degeneration (nAMD). This post hoc analysis of the CANTREAT trial explores the relationship between the maximal extension interval tolerated by patients receiving T&E ranibizumab and visual acuity outcomes. Methods: Treatment-naïve patients with nAMD were randomized to receive either a once-monthly dosing or T&E regimen of ranibizumab across 27 treatment centres in Canada and were followed for 24 months. For this post hoc analysis, patients in the T&E cohort were subdivided into the following groups based on maximum extension interval: 4 weeks, 6 weeks, 8 weeks, 10 weeks, and 12 weeks. The primary outcome was the change in ETDRS best-corrected visual acuity (BCVA) from baseline to month 24 while secondary outcomes included change in central retinal thickness (CRT). All results were reported using descriptive statistics. Results: A total of 285 participants undergoing T&E were enrolled in this post hoc analysis. At month 24, the change in BCVA from baseline was +8.5 ± 9.3, +7.7 ± 13.8, +4.4 ± 9.6, +4.4 ± 18.5, and +7.8 ± 14.8 letters in the 4-, 6-, 8-, 10-, and 12-week cohorts, respectively. The change in CRT at month 24 was −79.2 ± 95.0, −143.9 ± 128.9, −97.7 ± 101.1, −120.9 ± 105.3, and −133.2 ± 108.8 μm in the 4-, 6-, 8-, 10-, and 12-week cohorts, respectively. Conclusion: The capacity to extend does not necessarily associate with improved visual acuity outcomes, with the poorest change in BCVA seen in those extended 8–10 weeks. The highest change in BCVA and lowest decrease in CRT was in the group maximally extended for 4 weeks. There was a correlation between change in BCVA and change in CRT for other extension groups. Future studies should establish the predictive factors for successful extension in patients undergoing T&E in nAMD.

Mental fatigue and technical performance in elite rugby league

ABSTRACT The aims of this study were to determine the impact of elite rugby league competition on mental fatigue; and to investigate how mental fatigue influenced in-match technical performance. Twenty elite male rugby league players recorded their pre- and post-game subjective mental fatigue and had their technical performance analysed during matches across one competition season. Metrics were created to assess in-match technical performance and described the percentage of positive, neutral, and negative involvements for each player, while accounting for the context and difficulty of each involvement. Self-reported mental fatigue increased from pre-game to post-game (maximum a posteriori estimation [MAP] = 33.1, 95% high-density interval [HDI] = 26.9–39.8), with backs reporting higher changes in mental fatigue than forwards (MAP = 18.0, 95% HDI = 9.7–26.9). Larger increases in mental fatigue from pre-game to post-game were negatively associated with the adjusted percentage of positive involvements metric (MAP = −2.1, 95% HDI = −5.6 to 1.1). Elite rugby league players reported increased mental fatigue following competitive games, with backs reporting a greater increase than forwards. Mental fatigue impacted technical performance, whereby participants had a lower percentage of positive involvements when they reported being more mentally fatigued.

The impact of share‐pledging purposes on firm performance and innovation

AbstractResearch questionShare pledging by controlling shareholders can be motivated by business or personal purposes. We investigate whether the firm performance and innovation outputs are different for firms with controlling shareholders pledging shares to support their firm's financing (business‐pledging firms) and those pledging shares for increasing personal wealth (individual‐pledging firms).Research findingsUsing data from publicly listed Chinese firms, we find that business‐pledging firms are associated with higher changes in Tobin's Q and more patent outputs compared with individual‐pledging firms. In additional tests, we show that the impact of share‐pledging purposes on firm performance and innovative outputs is more pronounced for Chinese non‐state‐owned enterprises, which have relatively limited access to traditional bank loans.Theoretical implicationsIn this study, we bring new empirical evidence to agency theory, especially the “principal–principal” problem. We identify two inherently different purposes in share‐pledging cases—business pledging and individual pledging. We show that in business‐pledging cases, pledgers' interests become more aligned with outside shareholders, and pledgers have higher incentives to enhance firm value and innovation productivity, relative to individual pledging. This paper adds to the evidence on the bright side of share pledges.Practitioner implicationsThis paper sheds light on the recent policy debate regarding the costs and benefits of share pledging and has implications for regulators and investors. Thus, it may be vital for publicly listed firms to disclose the purposes of share pledging.

Characterization of the Products of the Catalytic Pyrolysis of Discarded COVID-19 Masks over Sepiolite

This research aims to develop a new strategy to valorize wasted COVID-19 masks based on chemical recycling by pyrolysis to convert them into useful products. First, surgical and filtering face piece masks, as defined in Europe by the EN 149 standard (FFP2), were thermally pyrolyzed at temperatures of 450, 500, and 550 °C, and the yields of valuable solid (biochar), liquid (biooil), and syngas products and their characteristics were determined. At low temperatures, biochar formation was favored over biooil and syngas production, while at high temperatures the syngas product yield was enhanced. The highest yield of biooil was found at a pyrolysis temperature of 500 °C, with both surgical and FFP2 masks achieving biooil yields of 59.08% and 58.86%, respectively. Then, the pyrolysis experiments were performed at 500 °C in a two-stage pyrolysis catalytic reactor using sepiolite as a catalyst. Sepiolite was characterized using nitrogen adsorption–desorption isotherms and Fourier-transform infrared spectroscopy. Results showed that the two-stage process increased the final yield of syngas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks). Furthermore, the composition of the biooils significantly changed, increasing the amount of 2,4-Dimethyl-1-heptene and other olefins, such as 3-Eicosene, (E)-, and 5-Eicosene, (E)-. Additionally, the methane and carbon dioxide content of the syngas product also increased in the two-stage experiments. Ultimately, the effect of sepiolite regeneration for its use in consecutive pyrolysis tests was examined. Characterization data showed that, the higher the use-regeneration of sepiolite, the higher the modification of textural properties, with mainly higher changes in its pore volume. The results indicated that the pyrolysis of face masks can be a good source of valuable products (especially from biooil and syngas products).

Ex-vivo effects of propolis quantum dots-nisin-nanoquercetin-mediated photodynamic therapy on Streptococcus mutans biofilms and white spot lesions.

White spot lesions (WSLs) remain one of the most critical adverse sequelae of fixed orthodontic treatment, despite materials and techniques advances in orthodontics. WSLs seem to be a multi-factorial interaction including increased microbial plaque due to intrabuccal appliances that limit the oral-cleansing mechanism and change in the oral microbiome during fixed appliance wear. The aim of this study was to investigate the synergistic effect of propolis quantum dots (PQD), nisin (Nis), and quercetin nanoparticles (nQCT)-mediated photodynamic therapy (PQD-Nis-nQCT-mediated aPDT) in the eradication of Streptococcus mutans biofilms and the remineralization of WSLs ex-vivo. The cytotoxicity of PQD-Nis-nQCT composite on human gingival fibroblasts was evaluated using neutral red. Intracellular reactive oxygen species (ROS) generation following PQD-Nis-nQCT-mediated aPDT was measured. Enamel slabs were prepared and demineralized using a demineralization solution containing S. mutans. Demineralized enamel slabs were divided into 9 groups (n=10) and treated in the following groups: 1) Artificial saliva (negative control), 2) 2% neutral sodium fluoride gel (NSF; positive control or treatment control, 3) PQD, 4) Nis, 5) nQCT, 6) Nis-nQCT, 7) PQD-Nis-nQCT 8) Blue laser irradiation (light), 9) PQD-Nis-nQCT with irradiation (PQD-Nis-nQCT-mediated aPDT). Then, the surface changes, microhardness, and surface topography of the demineralized slabs were examined following each treatment using DIAGNOdent Pen reading, digital hardness tester, and SEM, respectively. After the determination of minimum biofilm eradication concentration (MBEC) of PQD, Nis, and nQCT by microtiter plate assay, the synergistic antimicrobial effects of PQD and Nis-nQCT were determined via evaluation of fractional biofilm eradication concentration (FBEC) index. The anti-biofilm effects of each treatment on S. mutans were assessed using a colorimetric assay. Thevirulence‑associated gtfB gene expression was assessed following PQD-Nis-nQCT-mediated aPDT byquantitative real‑time PCR. PQD-Nis-nQCT at 2048µg/mL had no significant cell cytotoxicity on human gingival fibroblasts compared to the control group (P > 0.05). A significantly increased (7.6 fold) in intracellular ROS was observed following PQD-Nis-nQCT-mediated aPDT (13.9 ± 1.41) when compared to the control (1.83 ± 0.13). Following each treatment, the microhardness of the demineralized enamel surface significantly increased except for the artificial saliva (negative) and blue laser irradiation groups. The highest change in microhardness improvement was detected in the PQD-Nis-nQCT-mediated aPDT group (P < 0.05). Also, DIAGNODent Pen reading revealed the highest significant improved change in the level of mineralization degree in the PQD-Nis-nQCT-mediated aPDT group. Nis and blue light irradiation groups, like the artificial saliva-treated demineralized enamel slabs (control group), did not lead to remineralization (P > 0.05). Also, the PQD-Nis-nQCT-mediated aPDT treatment results obtained from SEM revealed that remineralization of demineralized enamel slabs in that group has significantly improved compared to the others. Light-activated nQCT, PQD, Nis-nQCT, and PQD-Nis-nQCT composite significantly reduced pre-formed biofilms of S. mutans compared with unactivated forms of test materials. The relative expression level of the virulence gtfB gene was significantly decreased (7.53-fold) in the presence of PQD-Nis-nQCT-mediated aPDT (P < 0.05). PQD-Nis-nQCT-mediated aPDT can be used for the eradication of S. mutans biofilms and remineralization of WSLs. The found in vitro efficacy should be tested further through clinical studies.

Climatic analysis of drought and its impact on the vegetation cover in the district of Heet using geographic information systems

The research concluded that the drought in the study area was clear, as the moderately dry variety ranked first with a total of (33) repetitions, then came the moderately humid variety with a frequency of (32) repetitions, while the very, very dry and very very wet cultivars were the lowest. Repeatedly, it reached (1, 3) repetitions for each of them, respectively, and the change of rainfall in the Heet station, which is the highest change among the rest of the studied stations, as the change during the study period reached (-40.92 mm), while the Ramadi station was the least changeable, as The change in rainfall during the study period at that station was (-3.135 mm). As for the vegetation cover, it was found through the research that the category of weak vegetation cover recorded a clear variation, as the highest area was during the year (2009) when it reached (6160.5) square kilometers, with a rate of (78.4)%, and this indicates that this year is the driest among the The years studied, while the year (2018) was the least of the years, as the area of this class amounted to (2612.9) square kilometers, with a rate of (33.3%). As for the very dense vegetation category, which is the highest degree of vegetation cover, it had the highest area during the year (2018), when it reached ( 426.8) km 2, with a rate of (5.4)%, and this indicates that this year is the most humid among the study years, which

Color stability of three commercial resin cements after accelerated aging.

This study aimed to assess the color stability of resin cements subjected to xenon radiation and evaluate their color change (ΔE) during time. In this in vitro experimental study, 15 specimens (8 mm in diameter and 2 mm in height) were made from a light-cured resin cement (Choice 2, Bisco, USA) and two dual-cured resin cements (Panavia F2 and V5, Kuraray Co, Ltd, Osaka, Japan). For assessment of color change, ΔE parameters were measured immediately (ΔE1) and 24 h (ΔE2) after polymerization using XRiteCi64 spectrophotometer. Next, they were subjected to xenon lamp radiation (122 h at 35C° and 22% humidity in off mode and 95% in light mode). Then, their color change was measured again (ΔE3). The mean ΔE and standard deviation of all specimens were calculated, and data analysis was done using analysis of variance and Tukey's honestly significant difference. L* values had a tendency to decrease and Panavia F2 and Choice 2 had the highest change after accelerated aging. The comparison of Δa and Δb showed no significant difference between cements except Δa in Panavia F2. All the values were clinically acceptable (ΔE >3.3). The lowest Δ E1 was for Panavia V5 and the highest Δ E1 was measured for Panavia F2. After accelerated aging, there was no significant difference between Panavia V5 and choice 2 (P > 0/05). Following polymerization and under xenon radiation, ΔE of all the specimens was clinically acceptable.

Response of Maize Yield and Nutrient Uptake to Indigenous Organic Fertilizer from Corn Cobs

Indonesia’s corn harvest area is decreasing so that corn production is also decreasing. The use of suboptimal land can be done to increase the harvested corn area by adding nutrients with organic fertilizers. One of the organic fertilizer ingredients is corn cob waste. The aim of the study was to examine the role of corn cob fertilizer on the growth, yield and nutrient uptake of corn. The study used a completely randomized block design with one fertilization factor with six levels, namely chemical fertilizers and corn cob organic fertilizer at a dose of 2.5, 5, 7.5, 10 or 12.5 tons/ha. Corn cob organic fertilizer has met the standard as an organic fertilizer with an organic C content of 62.21% and organic matter of 85.71%, ranking it in the high category. The total nitrogen is 1.44%, total phosphate is 1.43% and total potassium is 2.17%. Corn cob organic fertilizer had an effect on the leaf area index, root length, levels of chlorophyll a and chlorophyll b, weight of 100 seeds, cob diameter and phosphate uptake. Doses of 12.5 tons/ha produced the highest changes in chlorophyll a and b, root length and phosphate uptake. Phosphate and potassium uptake correlated with plant biomass and root length. Therefore, the results of the present study suggest that corn cob organic fertilizer is able to support the growth, yield and nutrient uptake of corn in sub-optimum land. Several gaps and research priorities in soil fertility have been identified, which need to be addressed in the future.

In vitro comparison of natural tooth-whitening remedies and professional tooth-whitening systems

BackgroundAn increasing number of patients are using natural homemade remedies such as strawberries, banana peels, coconut oil rinse, basil, lemon, activated charcoal, apple cider vinegar, baking soda, and turmeric to obtain whiter teeth. However, studies on these natural whitening products are limited. AimTo evaluate the effectiveness of different homemade tooth-whitening agents in vitro. Materials and methodsNinety caries-free extracted anterior and premolar teeth were collected, cleaned, and sectioned at the roots. The teeth were mounted in epoxy resin (buccal surface) and stored in 0.2 % thymol solution, and were treated with one of the following six whitening agents: baking soda, activated charcoal, lemon juice, strawberries, Colgate Optic Whitening toothpaste, and Opalescence 20 % home-bleaching system. The enamel shade in each sample was measured four times using a spectrophotometer. Baseline measurements for ΔE and (L*, a*, b*) were obtained, and the second measurement was obtained after 5 days. The third reading was obtained on the 10th day, and the fourth reading was obtained at the 4th week to measure colour stability. One-way analysis of variance and post-hoc Tukey tests were used for statistical analysis. ResultsΔE measurements showed a significant difference on the 10th day in all groups except the lemon group (P = 0.164), while all groups showed a statistically significant difference at the 4th week. The mean colour change differed remarkably between the first and fourth readings. The highest change was observed in the lemon group (44.0 ± 2.9), closely followed by the Opalescence 20 % and Colgate Optic Whitening toothpaste groups. The lowest change was observed with strawberries (38.2 ± 4.8). ΔE showed a significant difference in all groups except the turmeric group. ConclusionStatistically significant differences were obtained with baking soda, activated charcoal, strawberries, lemon juice, Colgate Optic Whitening toothpaste, and Opalescence 20%. Further studies are required to evaluate the effects of these agents on surface roughness and colour stability.