Search Results (204)

This article utilized hourly temperature, humidity, pressure and wind speed data from passion fruit meteorological observation stations in three southwestern cities of Fujian Province (Longyan, Sanming, Zhangzhou) from 2020 to 2022, as well as national ground conventional meteorological observation stations. BP neural network and stepwise regression method were applied to construct temperature prediction models for the passion fruit planting bases. The results showed that: (1) The simulation effect of the passion fruit station temperature prediction model based on BP neural network (referred to as BP model) was better than that of the model based on stepwise regression method (referred to as regression model). The average absolute error (MSE) of BP model (2.75–3.42 °C) was smaller than that of regression model (3.32–3.94 °C). (2) For the simulation results of daily temperature changes in the passion fruit station, the difference in hourly average temperature between the BP model predictions (regression model predictions) and observed temperatures at passion fruit station was −4.1–4.4 °C (−6.0–10.2 °C). The BP model showed a daily temperature trend that was closer to the measured values; (3) For the simulation results of high and low temperatures in the passion fruit station, the BP neural network model (regression model) showed a prediction error range of −5.6 °C to 5.2 °C compared to observed temperatures, while the stepwise regression model’s error range was −4.1 °C to 8.8 °C. The BP model’s predicted temperature trend was closer to the measured values. (4) Both models have significant shortcomings in the prediction of high-temperature individual cases and hourly averages, with relatively large errors (generally exceeding 3 °C), especially during the period from 10 to 16 o’clock. The future version needs to be optimized. Full article

This systematic literature review investigates how the concept of time is taught and learned in early mathematics education. While young children are commonly expected to learn how to tell time, this review explores what additional aspects should be emphasised to foster a deeper and more sustainable understanding of time. Using the EBSCO database, 36 relevant articles published up to December 2024 were identified. To cover different aspects related to the teaching and learning of time, peer-reviewed scientific articles as well as practice-based reports were included in the search. A majority of the articles focused on clock reading as an aspect of time. The aspects duration, sequencing, and measurement of time also frequently appeared whereas expressions of time, or cross-disciplinary aspects were seldom mentioned. Drawing on the findings, this review proposes a comprehensive framework outlining key aspects that should be included in early mathematics education to support the teaching and learning of time. Full article

As the electromagnetic spectrum is a limited and valuable resource, auctions have emerged as an effective tool for promoting efficient allocation and generating revenue. This article proposes a theoretical review of the most commonly used auction formats for spectrum auctions, highlighting the primary strengths and weaknesses of each format. Additionally, comparisons are made between the revenue generated by different auction formats and the corresponding countries in North and South America during the 21st century. The conclusion drawn is that the Combinatorial Clock Auction format is the preferred choice, as it consistently leads to more efficient allocation, as measured by the revenue generated from each auction. Full article

In the present study, a polarization rotation switch (PRS)-based all-optical ternary inverter circuit and ternary clocked SR flip-flop (TCSR) are proposed and discussed. The present scheme is designed by the polarization rotation of light in a waveguide coupled with a micro-ring resonator (MRR). The proposed scheme uses linear polarization-encoded light. Here, the ternary (radix = 3) logical states are expressed by the different polarized light. PRS-MRR explores the polarization-encoded methodology, which depends on polarization conversion from one state to another. All-optical ultrafast switching technology is employed to design the ternary NAND gate. We develop the ternary clocked SR flip-flop by employing the NAND gate; it produces a greater number of possible outputs as compared to the binary logic clocked SR flip-flop circuit. The performance of the proposed design is measured by the Jones parameter and Stokes parameter. The results of the polarization rotation-based ternary inverter and clocked SR flip-flop are realized using a pump–probe structure in the MRR. The numerical simulation results are confirmed by the well-known Jones vector (azimuth angle and ellipticity angle) and Stokes parameter (S₁, S₂, S₃) using Ansys Lumerical Interconnect simulation software. Full article

Among various plants, corn is the primary host damaged by Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae). After long-term regional colonization, its larvae feed on sweet waxy corn and fresh corn for extended periods. A question arises: Does long-term feeding on different corn varieties affect their rhythms? Currently, there are no reports addressing these issues. To facilitate the formulation of effective prevention and control measures, Zhengdan 958 and Zhenghuangnuo were selected as representative varieties of normal and sweet waxy corn, respectively, for laboratory experiments. S. frugiperda were fed the leaves of these two corn types over nine consecutive generations, thereby establishing distinct S. frugiperda strains associated with each corn variety. Additionally, a strain fed an artificial diet served as the control group. Through a comparative analysis of the emergence, movement, nutritional foraging, dormancy, mating, and oviposition behaviors of adult fall armyworms from different populations, differences in the six behavioral peak times among the strains were identified. RT-qPCR analysis indicated significant differences in the expression levels of four circadian clock genes across different populations and tissues of the fall armyworm. Feeding on different host plants influenced the expression of circadian clock genes and their associated behavioral rhythms. Our study showed that sweet corn is more conducive to pupation, mating, and oviposition. Because of these differences in adult insect rhythms, sweet corn may have an impact on the reproduction of fall armyworms in the Huang–Huai–Hai corn-planting region. Full article

Background: This study aimed to evaluate the impact of physical activity levels on selected biochemical markers (glucose, insulin, cholesterol, triglycerides, interleukin-6 [IL-6]), brain-derived neurotrophic factor (BDNF), cognitive functions, and additional macronutrient intake in postmenopausal women. Method: A total of 72 generally healthy women aged 55–73 from western Poland participated in the study. Physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ), resulting in two distinct groups: 56 women in the lower activity level group and 16 in the higher activity level group. We calculated body mass index (BMI), measured body composition and blood pressure, and conducted cognitive assessments, including the Mini-Mental State Examination (MMSE), motor and psychomotor skills tests, the Clock Drawing Test, and the Geriatric Depression Scale (GDS). Nutritional intake was evaluated using a detailed 3-day food record to analyze macronutrient consumption and total caloric intake. Results: A statistically significant difference in total blood cholesterol levels (p = 0.0277) was observed between the two groups, with the higher physical activity group showing elevated cholesterol levels. Although no other biochemical markers showed statistically significant differences, variations in BDNF, glucose, triglycerides, IL-6, and insulin levels were noted between groups. Moreover, correlations between these markers and cognitive performance, like motor and psychomotor speeds, varied depending on physical activity level. The analyzed dietary pattern of the studied group shows slight deviations from current nutritional recommendations. Conclusions: The findings suggest that physical activity level may influence certain biochemical markers and cognitive functions in postmenopausal women. While these results highlight the potential benefits of physical activity, further research is needed to clarify underlying mechanisms and to validate physical activity as an effective strategy for improving postmenopausal health. Full article

Daylight Saving Time (DST), involving clock shifts forward in spring and backward in autumn, was introduced to promote energy savings. However, its effectiveness remains controversial, especially in buildings with temporary occupancy like academic institutions, which have high daytime use but low summer occupancy. This study investigates the impact of DST transitions on energy consumption across seven campuses of two higher education institutions (HEIs) in northern Portugal and Spain, located in different time zones, using measured data from 2023. The analysis accounted for the structural and operational characteristics of each campus to contextualize consumption patterns. Weekly electricity consumption before and after DST changes were compared using independent samples t-tests to assess statistical significance. Results show that the spring transition to DST led to an average energy saving of 1.7%, while the autumn return to standard time caused an average increase of 1.2%. Significant differences (p < 0.05) were found in five of the seven campuses. Descriptive statistics and confidence intervals indicated that only sites with intervals excluding zero exhibited consistent changes. Seasonal energy demand appeared more influenced by academic schedules and thermal comfort needs—particularly heating—than by DST alone. Higher consumption coincided with periods of intense academic activity and extreme temperatures, while lower demand aligned with holidays and longer daylight months. Although DST yielded modest energy savings, its overall impact on academic campus energy use is limited and highly dependent on local conditions. The findings highlight the need to consider regional climate, institutional policies, user behavior, and smart technology integration in future energy efficiency analyses in academic settings. Full article

Objectives: The purpose of this study was to evaluate the diagnostic accuracy of glaucoma by establishing normative data on retinal nerve fiber layer (RNFL) thickness, specifically for healthy Koreans, using Huvitz spectral-domain optical coherence tomography (OCT). This study also aimed to compare the obtained RNFL thickness data with normative values provided by the Cirrus OCT system to identify any device-specific differences that could impact glaucoma diagnosis. Methods: This prospective observational study included 148 healthy participants aged 20–69 years at Gangnam Severance Hospital. Participants underwent comprehensive ophthalmologic evaluations, including RNFL thickness measurements using Huvitz OCT, which were compared with existing normative Cirrus OCT data. RNFL thickness was analyzed by quadrant (superior, inferior, nasal, and temporal) and clock-hour sectors. Statistical analysis included one-way analysis of variance (ANOVA) for group comparisons and linear regression to assess age-related changes. Results: The average RNFL thickness was 91.13 ± 13 μm, with the thickest measurements in the superior quadrant (111.85 ± 18.53 μm) and the thinnest in the nasal quadrant (68.35 ± 20.03 μm). Significant age-related thinning was observed across all quadrants, particularly the superior and inferior quadrants. Comparison with the Cirrus OCT system revealed significant differences, with the Huvitz OCT results showing thinner RNFL in the superior and inferior quadrants. Conclusions: This study established normative RNFL thickness data in healthy Koreans using Huvitz OCT, providing essential reference data for clinical glaucoma diagnosis. The differences between Huvitz and Cirrus OCT systems underscore the need for device- and population-specific normative data to improve diagnostic accuracy in glaucoma management. Full article

The evolving understanding of asthma and COPD pathomechanisms led to this study examining chronic obstructive lung diseases’ impact on cognitive decline—a growing concern in aging populations. We explored whether subunits of key inflammatory regulators NF-κB, c-Rel (neuroprotective), and p65 (neurodegenerative), are linked to cognitive impairment. A pilot study with an explorative design across three groups (asthma, COPD, and control) included 78 patients. Participants underwent assessments via 16 questionnaires (covering demographics, quality of life, disease control, and cognitive and psychiatric evaluations), spirometry, and blood sampling to measure c-Rel and p65 mRNA expression. While both c-Rel and p65 are NF-κB subunits, their expression levels differ independently. Median c-Rel expression was highest, and p65 lowest, in the group with the best cognitive function (control). The most notable correlations for both markers with PKA, CREB, MMSE, and HAM-D were in COPD. The significant association between p65 and the Clock-Drawing Test, without a corresponding link to MMSE, may indicate that a future correlation between p65 and cognitive decline, as assessed by CDT, is likely to emerge. Full article

Significant deviations between chronological and biological age can signal the early risk of chronic diseases, driving the need for tools that accurately determine biological age. While DNA methylation-based clocks have demonstrated strong predictive power for biological aging determination, their clinical application is limited by several barriers including high costs, the need to analyze hundreds of methylation sites using sophisticated platforms and the lack of standardized measurement tools and protocols. In this study, we developed a multivariate linear model using the analysis of eight CpGs within the promoter region of the very long chain fatty acid elongase 2 gene (ELOVL2). The model generated predicts biological age with a mean absolute error (MAE) of 5.04, providing a simplified, cost-effective alternative to more complex methylation-based clocks. Additionally, we identified sex-specific biological clocks, achieving MAEs of 4.37 for males and 5.38 for females, highlighting sex-related molecular differences in the methylation of this gene during aging. Our minimal CpG-based clock offers a practical solution for estimating biological age, with potential applications in clinical practice for assessing age-related disease risks and providing personalized healthcare interventions. Full article

This article aims to examine the real-time precise point positioning (PPP) solution’s accuracy utilizing the low-cost dual-frequency multi-constellation U-blox ZED-F9P module and real-time GNSS orbit and clock products from five analysis centers, including Bundesamt für Kartographie und Geodäsie (BKG), Centre National d’Etudes Spatiales (CNES), International GNSS Service (IGS), Geo Forschungs Zentrum (GFZ), and GNSS research center of Wuhan University (WHU). Three-hour static quad-constellation GNSS measurements are collected from ZED-F9P modules and geodetic grade Trimble R4s receivers over a reference station in Aswan City, Egypt, for a period of three consecutive days. Since a multi-GNSS PPP processing model is applied in the majority of the previous studies, this study employs the single-constellation GNSS PPP solution to process the acquired datasets. Different single-constellation GNSS PPP scenarios are adopted, namely, GPS PPP, GLONASS PPP, Galileo PPP, and BeiDou PPP models. The obtained PPP solutions from the low-cost module are validated for the positioning and precipitable water vapor (PWV) domains. To provide a reference positioning solution, the post-processed dual-frequency geodetic-grade GNSS PPP solution is applied; additionally, as the station under investigation is not a part of the IGS reference station network, a new technique is proposed to estimate reference PWV values. The findings reveal that the GPS and Galileo 3D position’s accuracy is within the decimeter level, while it is within the meter level for both the GLONASS and BeiDou models. Additionally, millimeter-level PWV precision is obtained from the four PPP models. Full article

Polygain™ (PG), a polyphenolic extract from sugarcane, has recently been identified as a potential additive to reduce methane (CH₄) emissions in livestock. This experiment examined the effects of PG on the enteric CH₄ emission from Holstein Friesian weaned calves. Calves were allocated to annual pasture grazing and received supplementary pellets (200 g/calf/day; Barastoc calf-rearer cubes—Ridley Corporation). The experimental design followed was a completely randomized design (CRD), comprising 24 female calves (4–5 months old) allocated to two equal groups; control (standard pellets) vs. treatment (pellets formulated by adding PG to control pellets to deliver 10 g PG/calf/day). Experimental diets were fed for three months between August and November 2023, including a two-week adaptation period. Calves were weighed at the start and at the end of the study. A GreenFeed (C-Lock Pvt Ltd.) emission monitoring unit (GEM) was used to measure GHG emissions from the experimental calves in their groups in a 2-day rotational cycle. During a visit to the GEM, the calves were encouraged to enter an enclosed area or individual feeding stall where enteric CH₄, CO₂, O₂, H₂, and H₂S measurements were taken. The results indicated a significant effect of PG supplementation on enteric methane emission in calves, with a lower production of CH₄ in calves supplemented with PG (26.66 ± 2.06 g/day) as compared to the control group (35.28 ± 1.39 g/day, p < 0.001). The CO₂/O₂ ratio in the treatment (235 ± 14) and control groups (183 ± 9.6) differed significantly (p < 0.001). Overall, PG supplementation (10 g/calf/day) reduced their average methane emission per day and did not adversely affect the growth and development of experimental calves, confirming its useful anti-methanogenic potential. Full article

Terrestrial and satellite communications, tactical data links, positioning, navigation, and timing (PNT), as well as distributed sensing will continue to require precise timing and the ability to synchronize and disseminate time effectively. However, the supply of space-qualified clocks that meet Global Navigation Satellite Systems (GNSS)-level performance standards is limited. As the awareness of potential disruptions to GNSS due to adversarial actions grows, the current reliance on GNSS-level timing appears costly and outdated. This is especially relevant given the benefits of developing robust and stable time scale references in orbit, especially as various alternatives to GNSS are being explored. The onboard realization of clock ensembles is particularly promising for applications such as those providing the on-demand dissemination of a reference time scale for navigation services via a proliferated Low-Earth Orbit (pLEO) constellation. This article investigates potential inter-satellite network architectures for coordinating time and frequency across pLEO platforms. These architectures dynamically allocate radio resources for clock data transport based on the requirements for pLEO time scale formations. Additionally, this work proposes a model-based control system for wireless networked timekeeping systems. It envisions the optimal placement of critical information concerning the implicit ensemble mean (IEM) estimation across a multi-platform clock ensemble, which can offer better stability than relying on any single ensemble member. This approach aims to reduce data traffic flexibly. By making the IEM estimation sensor more intelligent and running it on the anchor platform while also optimizing the steering of remote frequency standards on participating platforms, the networked control system can better predict the future behavior of local reference clocks paired with low-noise oscillators. This system would then send precise IEM estimation information at critical moments to ensure a common pLEO time scale is realized across all participating platforms. Clock steering is essential for establishing these time scales, and the effectiveness of the realization depends on the selected control intervals and steering techniques. To enhance performance reliability beyond what the existing Linear Quadratic Gaussian (LQG) control technique can provide, the minimal-cost-variance (MCV) control theory is proposed for clock steering operations. The steering process enabled by the MCV control technique significantly impacts the overall performance reliability of the time scale, which is generated by the onboard ensemble of compact, lightweight, and low-power clocks. This is achieved by minimizing the variance of the chi-squared random performance of LQG control while maintaining a constraint on its mean. Full article

Weaned Angus-cross steers (n = 69; body weight [BW] = 233 ± 29 kg) were used for the following purposes: (1) develop an assay to measure 3-methylhistidine (3MH) in blood samples to monitor changes in protein turnover, and (2) evaluate the effects of an implant (Revalor-G, 40 mg of trenbolone acetate, 8 mg of estradiol) or an implant plus individual supplementation via SuperSmart Feeder (SSF; C-Lock Inc., Rapid City, SD, USA) on animal growth, muscle growth, and nitrogen retention patterns in backgrounded beef steers. Steers were blocked by weight, trained to precision supplementation via SSF, and then assigned to one of three treatments: (1) grazing only [G], (2) grazing with implant [GI], or (3) grazing with implant plus individual animal supplementation via SSF at 0.75% BW [GIS] for 56 d of grazing study. Steers grazed a cowpea and pearl millet mixture until d 42, when forage became limiting, and steers were transitioned to an oat and annual ryegrass baleage. Steers were weighed and blood was collected every 14 d to determine plasma urea nitrogen (PUN), creatinine (CREAT), and 3-methylhistidine (3MH) concentrations. Ultrasound measurements of ribeye area (REA) were collected on d 0, 28, and 56. Data were analyzed using the GLIMMIX with treatment, day, and two-way interaction in the model. A novel, robust method for the determination of 3MH was developed and validated. The development of this 3MH method allows us to monitor changes in protein turnover in cattle over time, a metric which is related to production efficiency. A treatment-by-day interaction (p = 0.0050) was observed for BW and REA. Steer BW did not differ (p > 0.05) on d 0, 14, or 28 between treatments; however, on d 42, GI and GIS steers had a greater (p < 0.01) BW than G steers. On d 56, BW was greater (p < 0.0001) for GIS than GI and G, which not differ (p > 0.05). Total BW gain during the 56 d study was greater (p < 0.001) by 54% for GIS compared to GI or G. For GI, the total BW gain was greater (p < 0.01) by 18% compared to G. On d 56, the REA of GI and GIS steers was greater (p < 0.001) than of G steers. Steers in the GI treatment group had a greater PUN and PUN–CREAT ratio concentrations than the GIS steers. Both G and GI steers had greater 3-methylhistidine (3MH) concentrations compared to GIS steers on d 28. Our results demonstrate that the supplementation of implanted steers improves growth and improves nitrogen utilization during backgrounding on forage diets. This research illustrates that animal and muscle growth may be limited in grazing animals implanted with combination implants (estrogenic and androgenic compounds) when supplementation is not included. Full article

As one of the most precise timekeeping instruments ever developed, the optical clock will be used as the measuring equipment for the next generation of second definition. The demand for the miniaturization of optical clocks is progressively urgent. In this paper, a multi-channel radio frequency (RF) module with a 20% volume of the commercial module is designed and implemented for the transportable ⁴⁰Ca⁺ ion optical clock. Based on the double-crystal oscillator interlocking technique, a 1 GHz low-phase noise reference source is developed for direct digital synthesis. Through the simulation and optimization of the signal link design, the frequency range of the low phase-noise RF signal can reach 0–400 MHz with a 4 μHz resolution. Through two-stage power amplifying with different kinds of filters, it can achieve an output power of up to +33 dBm (2 W) at 100 MHz with a 25 dB phase noise lower than the commercial module at 1 Hz, and its third harmonic suppression ratio has been reduced by more than 20 dB at the frequency point of 300 MHz. This multi-channel RF module is used for the power stability and timing control test of a 729 nm clock laser to meet the requirements of the transportable ⁴⁰Ca⁺ optical clock. Additionally, this module can also be applied to other quantum systems such as the quantum absolute gravimeter, quantum gyroscopes, and quantum computers. Full article