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MicroRNAs (miRNAs) are typically non-coding RNAs of 18–26 nucleotides (nts) that are produced endogenously and regulated post-transcriptionally through degradation or translational repression. Since miRNAs are evolutionarily conserved, their preservation is essential for important regulatory functions in plant development, growth, and responses to environmental stress. Sorghum bicolor (sbi) is a valuable food and fodder crop which is grown worldwide. A range of sbi miRNAs were identified so far as being connected to plant development and stress responses. Herein, we employed a variety of bioinformatics tools for miRNA profiling in sbi and a PCR-based platform for the validation of these miRNAs. In total, 74 new conserved sbi miRNAs from 52 miRNA families have been predicted. Using the psRNA Target method, 10613 different protein targets of these predicted miRNAs have been attained. These targets include 54 GO-terms which have substantial targets in the biological, molecular, and cellular processes. We particularly found that the sbi-miR1861c and sbi-miR5050 are involved to regulate sulphur compound biosynthetic process, while the significant spliceosomal complex is regulated by sbi-miR815b and sbi-miR7768b. Also, we report that the pre-ribosome, electron transport chain, cell communication, cellular respiration, protein localization, and photosynthesis are controlled by sbi-miR2907b, sbi-miR530, sbi-miR7749, sbi-miR1858a, sbi-mi7729a, and sbi-miR417, respectively. The identification and validation of these novel sbi miRNAs shall contribute a lot in improving the crop yield and ensure sustainable agriculture. [ABSTRACT FROM AUTHOR]

There are various methods for energy production, such as hydro power, nuclear plants, and coal plants, but some of these sources emit CO 2 , posing harm to the environment. Consequently, the global trend is shifting towards renewable energy sources that have minimal environmental impact. The photovoltaic (PV) system is a notable renewable energy source as it generates power without harmful emissions. However, the effectiveness of a PV system varies based on location. This study presents a decision-making procedure to identify an optimal location for a photovoltaic (PV) system in Pakistan. Initially, a geographic information system (GIS)-based multi-criteria decision-making technique is employed to identify factors influencing the selection of an optimal PV system location. An analytic hierarchy process is then utilized to create a comparison decision matrix, balancing four primary criteria and ten sub-criteria, providing a comprehensive evaluation of potential sites. Ten cities across Pakistan, each with a population exceeding 300,000, are selected for assessment. These cities are evaluated and categorized using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach. The results indicate that Karachi is the ideal site for a PV system. This analytical approach aids in early planning, facilitating the identification of optimal locations for PV systems in Pakistan. [ABSTRACT FROM AUTHOR]

As a springboard to explore novel potent inhibitors of cholinesterase enzymes (AChE and BChE) responsible for causing Alzheimer disorder, the current study was conducted to synthesize pyrrole derived triazole based Schiff base scaffolds by facile synthetic route. These compounds were validated by 1HNMR, 13CNMR and HREI-MS. All these scaffolds (1–16) were examined for their inhibitory activity against AChE and BChE in contrast to Donepezil (10.20 ± 0.10 and 10.80 ± 0.20 µM) and Allanzanthone (12.40 ± 0.10 and 13.10 ± 0.10 µM). All pyrrole derived triazole based Schiff base scaffolds (1–16) showed varied range of inhibitory potentials against acetylcholinesterase and butyrylcholinesterase enzymes with lowest inhibition concentration values ranging from 5.10 ± 0.40–27.10 ± 0.10 µM (for AChE) and 5.60 ± 0.30–28.40 ± 0.30 µM (for BChE). SAR analysis of these derivatives revealed analog 7 as lead molecule against targeted enzyme, while analog 6 and 11 were ranked as second and third most potent scaffolds. Binding affinity and selectivity of potent molecules against targeted enzymes were examined by molecular docking and obtained results showed that potent molecule have versatile significant binding interactions with stated enzymes. Furthermore, safety profiles of potent analogues were predicted via ADMET protocols. [ABSTRACT FROM AUTHOR]

The COVID-19 epidemic highlighted the relation between leadership approach and organizational success. The research shows the impact of transformational leadership and the COVID-19 shutdown on employees' tension, anxiety, and productivity. The principal objective of this research is to explore the influence of daily perceived stress on mental wellness and its resulting impact on staff productivity. The investigation employed a combination of quantitative and qualitative methodologies, using verifiable knowledge and empirical data provided in numerical form. The results show strong evidence to support the claim that the stress induced by the COVID-19 lockdown significantly impairs workers' performance. However, it also highlights the substantial beneficial influence of transformational leadership on employees' performance. A relationship has found with the COVID-19 pandemic stress and higher levels of negative and upsetting feelings, as well as higher levels of transformative leadership. The effects of the stress on the psychological well-being of employees have been proven worse by the fact that they have already been through it. [ABSTRACT FROM AUTHOR]

The main objective of the research is to investigate the impact of export divergence, and CEO-pay performance sensitivity on CEO compensation. We construct a new degree of export-related diversification for Chinese listed firms and find that higher levels of export-related diversification results in higher levels of CEO compensation. Moreover, export diversification enhances the CEO pay-performance sensitivity. Our findings are consistent with a variety of model assumptions, such as a Difference-In-Difference regression estimate that accounts for missing variables. Finally, we find evidence that export diversification increases CEO compensation by reducing information symmetry. The study on business diversity is expanded in this work, and it offers compelling indication of the link among such diversification and CEO recompense. [ABSTRACT FROM AUTHOR]

Empirical studies provide a convincing argument that a cleaner environment ensures a better standard of living and has far-reaching economic gains. Researchers have widely tested the Environmental Kuznets Curve (EKC) to identify the link between emissions and economic activity. Still, they majorly ignored exploring the factors that could work as policy interventions in shifting or flattening the EKC curve for human wellbeing. This study has explored selected 50 countries for exploring the potential of leadership in moderating the EKC relationship. The Panel data model results showed that leadership is instrumental in moderating EKC. Some of the prominent indicators, like Team-Oriented Leadership and Participatory Leadership have shown an ability to reduce the net Carbon Dioxide (CO2) emissions in the economy. Policymakers could inculcate a sustainable/green leadership environment in achieving several Sustaimable Development Goals (SDGs). [ABSTRACT FROM AUTHOR]

The present research aims to shed light on the effects of monetary policy on China's tourism market development from 2004 to 2016. Monetary policy plays an increasingly important role in China's economy. With the Chinese economy in rapid development, the country's tourism market experienced significant growth. This study uses the Granger Causality test and factor-augmented vector auto-regression (FAVAR) model to identify the effects of monetary policy on China's tourism market through four transmission mechanism channels. Our results show that macroeconomic growth promotes China's tourism market development. Moreover, the money supply channel, exchange rate channel, and other assets channel have significant and adverse effects on China's tourism market development. [ABSTRACT FROM AUTHOR]

This study focused on the spatial effects of CO2 determinants, using data from 43 European countries between 1996 and 2018. Tests proved the existence of the spatial Durbin model. The findings indicate that the logarithm of GDP per capita, urbanization, and energy use have enhancing effects on CO2 emissions, but that these effects are meaningless for trade openness. Most of the coefficients provided insignificant results, while six financial development indicators were entered into the model in a straight line. The addition of the term "interaction between energy intensity and financial development" improved the effects of all of the components significantly. The phrase's negative and significant coefficient predicts increased energy intensity efficiency as a result of the development of multiple financial production components. The analysis of spatial effects reveals that control variables in adjacent countries have negligible effects on CO2 emissions. Overall, the findings show that CO2 emissions are falling as neighboring countries' productivity and financial development rise. The findings indicate that financial development in neighboring countries has comparable effects on CO2 emissions as domestic financial development. As a result of these findings, European countries have reached a point of financial integration. [ABSTRACT FROM AUTHOR]

Motivated from the shortage of the existing research studies on impacts of dangerously contagious diseases on firms' financial performance, this study sheds light on the impacts of Coronavirus (Covid-19) outbreak on financial performance upon on the quarterly data of 126 Chinese listed firms across 16 industries. Overall, the Covid-19 outbreak reduced Chinese listed firms' financial performance proxied by the revenue growth rate, ROA, ROE, and asset turnover. This outbreak's negative effects on Chinese firms' profitability were much smaller than that on their revenue growth rates. While this outbreak's negative effects on financial performance of Chinese listed firms were bigger for those that were seriously affected by this pandemic like airlines, travel, and entertainment (ATE), this pandemic's effects were positive for the medicine industry. In the meanwhile, Chinese listed firms that located in high-risk regions suffered a bigger financial loss during the outbreak, and especially there was a strong Hubei effect. The corporate culture and CSR moderated the inverse relationship between this outbreak and Chinese firms' financial performance. Findings of this study contribute to enrich the existing literature on impacts of the Covid-19 outbreak on firms' financial performance worldwide and suggest helpful practical and theoretical implications. [ABSTRACT FROM AUTHOR]

This research aims to develop an ecological carrying capacity index for the ecological environment under the principle of the pressure-state-response framework model and discusses the coupling coordination of ecological environment pressure, state, and response system of the urban region in china from 2011 to 2020. Furthermore, predicated the degree of security warning for each year while establishing the ecological carrying capacity index and the urban ecological coupling model. Results specify that the coordination degree of urban ecological development in Nanchang, Jiangxi has been improved year by year, the ecological carrying capacity security index shows an upward tendency from the overall view, and the security warning degree rises from comparative insecurity to comparative security. The analysis demonstrates that in the process of national ecological civilization construction demonstration zone construction, the ecological resources and environmental policies adopted by Nanchang city have played a great role in promoting ecological security. However, the ecological security index in Nanchang is still below 0.6, far from the high-security level (0.77), and the government and the public still need to do a lot to improve ecological security. [ABSTRACT FROM AUTHOR]

In today's dynamic environment, delivering exclusive and meaningful consumer interactions is critical for brands to stand out. In this sense, we suggested that consumer loyalty is influenced by online brand interactions due to brand familiarity. In a cross-sectional study conducted on 307 customers of leading and popular online selling brands in China across different industries, we found that online brand experience has significant and positive effect on customer satisfaction. Affective brand experience has a statistically negligible direct impact on customer satisfaction, emotional brand experience has a substantial and optimistic direct effect on customer satisfaction, and behavioural brand experience has a significant and harmful direct effect on customer satisfaction. In addition, it was discovered that brand awareness has a major mediating impact in the relationship between affective and behavioural brand experiences and consumer satisfaction, but no significant mediating influence in the relationship between emotional and cognitive brand experiences and customer satisfaction. [ABSTRACT FROM AUTHOR]

The popularity of green economy as an innovative technique and financial mechanism has soared as a result of this exchange, the gross domestic product (GDP); transition economy (TE); CO2 emissions; human capital (HC); Government Fund Strategy (GFS); green finance (GF) play a very important role. When it comes to advancing genetic civilization, China's achievements in the field of green money have become firm proof of the country's progress. China has come to terms with the fact that it cannot continue on its current path of promoting monetary development at the expense of the environment, both for its own people and for the sake of the global community. The country has prioritized environmental concerns over equality with others through economic, political, social, and other factors. Furthermore, in order to accomplish the enormous goal, China's cross-country coal use must be covered to allow it to peak before 2020, and fossil fuel byproducts must peak before 2030. This article argues that China's "green drive" is a cause for optimism and concludes by arguing that the top 2030 goal for fossil fuel byproducts is ambitious but doable. [ABSTRACT FROM AUTHOR]

This research aims to investigate the effect of foreign direct investment on carbon emissions through the panel ARDL method using annual data for the 1990–2016 period for the newly industrialized countries (NICs), including China, Malaysia, Mexico, Philippines, Thailand, Turkey, India, and Brazil. The stationarity of the series was obtained through LLC, IPS, and Fisher ADF panel unit root tests, the cointegration relationship with the panel ARDL-PMG approach, and the causality relationship with Dumitrescu and Hurlin (DH) tests. As a result of the long-term analysis, the foreign direct investment, energy consumption, and trade openness have a positive and significant impact on carbon emissions, whereas economic growth has a negative and significant impact on carbon emissions. The result shows that a percent increase in foreign direct investment increases carbon emissions by 0.03%. As a result of the short-term analysis, it was seen that the coefficient of the error correction term (ECT) was negative and statistically significant. According to DH panel causality test results, there exists a bidirectional causality relationship among energy consumption and carbon emissions, and a unidirectional causality relationship from economic growth and trade openness to carbon emissions and from carbon emissions to foreign direct investment. As policy implication, in industrialized countries especially China and India, there is a greater need to invest in green energy consumption at a larger scale to achieve future sustainable development goals. [ABSTRACT FROM AUTHOR]

For nations already facing pollution issues, fossil fuel energy consumption is deteriorating living standards. Though prevailing infrastructure makes fossil fuel energy use feasible for production, it still pollutes our environment. This study in the domain of environment and development assesses the impact of fossil fuel energy consumption on the infant mortality rate in 15 Asian economies during 1996 and 2019. The living standards are assessed using infant mortality rate, while non-linear fossil fuel energy consumption is used with gross capital formation, employment, and preprimary education as independent variables. The feasible generalized least square method evaluates the effects. The study concludes that fossil fuel energy consumption follows a U-shaped relationship explaining infant mortality. The results point out that over-consumption of fossil fuel energy is deteriorating the living standards considering low air quality levels in Asian economies. [ABSTRACT FROM AUTHOR]

The present research aims to investigate the impact of air pollution on the number of mortalities caused by COVID-19 per Pakistani province. To do so, for each independent area of Pakistan, the observed mortality due to COVID-19 has been standardized over the entire population using standard age groups ranging from 0 to 4, 5 to 9, 10 to 14,..., 65, and above years, supported by the 2017 state people census. The impact of air pollution and COVID-19 transience among Pakistani areas, Islamabad Capital Territory (ICT), and the Federally Administered Tribal Region (FATA) was analyzed by a multiple-linear regression model, while the broad collection of attributes was observed by the resources of local spatial autocorrelation indicators, including the spatial portion of COVID-19 association. The result indicates that the observed mortality rate is much higher than predicted in certain provinces, namely, the Khyber Pakhtunkhwa and Punjab provinces, and the prevalence of PM10 was independently linked to mortality due to the corona virus. Additionally, the results of the local spatial autocorrelation indicators on the standardized mortality rate and PM10 define a collection of very higher ideologies in the broad range of KPK and the southern part of Punjab province, respectively, with a definite degree of connection between the two distributions in the Khyber Pakhtunkhwa region. In brief, this research seems to find a justification for confirming the existence of a correlation between the possibility of COVID-19 mortality and air pollution, more precisely considering air pollutants (i.e., particulate (PM10) and land take-over. To this end, the need to mediate in favor of measures aimed at eliminating emissions in the environment will be reiterated by speeding up current proposals and policies aimed at all causes of atmospheric pollution: urbanization, water and manufacturing, home heating, and transportation. [ABSTRACT FROM AUTHOR]

Environmental challenges are as vast as the universe, allowing for numerous studies on their various dimensions. Using 17 data sets from Asia-Pacific countries between 2000 and 2017, this study attempted to investigate the economic factors influencing the ecological footprint of the fishing sector. The primary contribution of this study is to examine the effects of nine economic freedom indicators, as well as other control variables, on the status of fishery resources due to environmental pressure. The findings confirm the environmental Kuznets curve (EKC) hypothesis in the fishing grounds footprint, indicating that GDP per capita growth has a positive and significant effect, even though its squared form coefficient is negative. Other control variables, including natural resource rents, urbanization, and energy intensity, do not significantly affect the fishing footprint. The different components of economic freedom show different effects, while their cumulative effects in the form of the total economic freedom index positively affect the footprint of fishing and lead to increased extraction from fishing resources. The results show that the government integrity, tax burden, business freedom, and monetary freedom indices increase the fishing footprint. In contrast, indices of trade freedom and investment freedom, by highlighting the adverse effects of fishing on the environment, help countries reduce pressure on their aquatic resources. The findings of this study highlight the importance of examining how various dimensions of economic freedom affect the ability to manage fishery resources effectively. [ABSTRACT FROM AUTHOR]

Nowadays traditional techniques of living and earning are being transformed to modern smart technologies, taking their inspiration from the emerging trends. Agriculture and its supply chain are also one of the major domains of research that need attention for its growth especially in developing countries like Pakistan. Food safety and its supply are drawing the world's attention towards its importance and people are focusing on it because of health hazards. This research, presents a Combo smart model with a novel scheme for the transformation of traditional agriculture to smart agriculture, taking into consideration both blockchain and Internet of Things (IoT) characteristics. The system proves to be reliable, automatic, open, and biological food tracks built with the features of Blockchain IoT devices. This system provides equal opportunity to all stakeholders involved in the agricultural food supply chain; even they are not familiar with each other and may not trust. IoT devices are added to the smart model to reduce human interference for data recording and verification. For validation purposes, the proposed scheme is compared to our own scheme, which uses only IoT devices deployed in the monitoring field without a blockchain. [ABSTRACT FROM AUTHOR]

In Wuhan city, China, a pneumonia-like disease of unknown origin triggered a catastrophe. This disease has spread to 215 nations, affecting a diverse variety of persons. It was formally called extreme acute respiratory syndrome coronavirus 2 (SARS CoV-2), also known as coronavirus disease, by the World Health Organization as a pandemic. This pandemic forced countries to enforce a socio-economic lockdown to avoid its widespread presence. This study focuses on how the pollution of particulate matter during the coronavirus pandemic in the period from 23 March 2020 to 31 December 2020 was reduced compared to the pre-pandemic situation in the country. The improvement in air quality and atmosphere due to the coronavirus pandemic in Pakistan was identified by both ground-based and satellite observations with a primary focus on the four provincial capitals and country capitals, namely, Peshawar, Karachi, Quetta, Lahore, and Islamabad, and statistically verified through paired Student's t test. Both datasets have shown a significant decrease in the levels of PM2.5 pollutions across Pakistan (ranging from 15 to 35% for satellite observations, while 27 to 61% for ground-based observations). The result shows that poor air quality is one of the key factors for a higher COVID-19 spread rate in major Pakistani cities. By extending the same investigation across the nation, there is a greater need to investigate the connections between COVID-19 spread and air pollution. However, both higher population density rates and frequent population exposure can be partially attributed to increased levels of PM2.5 concentrations before the pandemic of the coronavirus. [ABSTRACT FROM AUTHOR]

This paper examined the impacts of financial development on environmental quality in Malaysia, using the sum of financial access, depth, and efficiency as auxiliary variables for financial development from 1987 to 2020. The autoregressive distributed lag method was used to examine whether a level relationship (long run) existed among the variables. The paper found a long-run relationship among the variables. Financial development, population growth, economic growth, and energy usage positively significantly contribute to environmental degradation in both the short and long run, while squared economic growth significantly enhanced environmental quality in both the short and long run. Hence, environmental carbon Kuznets curve (ECKC) hold in Malaysia. [ABSTRACT FROM AUTHOR]

Our research examined the renewable energy consumption, foreign direct investment, international trade, and tourism impact on carbon dioxide discharge using system GMM, FMOLS, and DOLS models in selected developed countries of Europe and developing countries of Asia Pacific of the global employment for a period spanning 2000 to 2020. The results indicate that foreign direct investment and tourism comprise a positive affiliation with carbon discharge. Simultaneously, renewable energy utilization with international trade significantly negatively relates to carbon emissions in developed countries. On the other hand, renewable energy consumption, tourism, and global trade play an essential role in increased carbon emissions. Still, carbon dioxide emission decreases by foreign direct investment in developed countries. It is discovered that with long-run estimators, the long-run relationship of variables through carbon discharge in developed and developing countries. The study findings are considered useful in future planning of renewable energy utilization, FDI, tourism policies, and trade openness to improve ecological excellence. [ABSTRACT FROM AUTHOR]

The use of automated network planning systems is crucial for reducing the deployment cost and planning time of passive optical telecommunication networks. Mixed-integer linear programming (MILP) is well suited for the purpose of modeling passive optical networks; however, excessive computing times for solving large-scale problem instances render these approaches impractical. This research presented a formulation that was based on MILP. It is for the issue of optimum dimensions of fiber equipment of the FTTH optical-access network (FTTH-OANs). The key objective is to minimize the capital expenditure associated with the implementation of FTTH-OAN, i.e. the expense of passive and active tools (splices, fiber terminations, closures, cables, optical splitters, and OLT cards, etc.) site planning costs and the cost of labor needed. This formulation is installed and tested. The key results are derived from practical physical systems installed in homes. [ABSTRACT FROM AUTHOR]

Purpose: Intrafollicular fluid (IFF) melatonin plays a decisive role in maintaining granulosa cells' DNA integrity and protects them against apoptosis. It reduces oxidative stress and improves the oocyte quality with a higher fertilization rate. Method: This prospective study investigated the antioxidant property of IFF melatonin and its impact on IVF outcome parameters. We also explored the relative expression of five microRNAs (miR-663b, miR-320a, miR-766-3p, miR-132-3p, miR-16-5p) and levels of cell-free DNA (cfDNA) by real-time PCR in unexplained infertile patients. We collected 425 follicular fluid (FF) samples containing mature oocytes from 295 patients undergoing IVF. Results: Patients were subgrouped based on IFF melatonin concentration (group A ≤ 30 pg/mL, group B > 70 to ≤ 110 pg/mL, group C > 111 to ≤ 385 pg/mL). Our results showed that patients with ≤ 30 pg/mL IFF melatonin levels have significantly higher oxidative stress markers, cfDNA levels, and lower relative expression of miR-663b, miR-320a, miR-766-3p, miR-132-3p, and miR-16-5p compared to other subgroups (p < 0.001). Similarly, they have a low fertilization rate and a reduced number of high-quality day 3 embryos. Conclusion: Findings suggest that the therapeutic use of melatonin produces a considerable rise in the number of mature oocytes retrieved, fertilization rate, and good-quality embryo selection. Furthermore, miRNA signature enhances the quality of embryo selection, thus, may allow us to classify them as non-invasive biomarkers to identify good-quality embryos. [ABSTRACT FROM AUTHOR]

Optical communication systems (OCSs) mainly represent the backbone of modern long-haul communication networks because of low loss transmission over long distances and ultra-high capacity. However high data-rate transmission through optical fiber suffers from deterioration due to nonlinear impairments, such as four-wave mixing (FWM) in particular. At high launch power levels, which are required for the long-haul transmission over hundreds of km, these nonlinear effects become more severe which imposes a challenge to achieve satisfactory transmission performance. In this paper, a theoretical model for the FWM effects and its mitigation is presented and validated through simulation results. Moreover, two other nonlinear effects, polarization mode dispersion and nonlinear dispersion variations are also investigated for various values of launch power level. The transmission performance of the proposed OCS model is evaluated on the basis of bit error rate, optical signal-to-noise ratio and quality factor using different transmission channel parameters such as effective area, nonlinear refractive index, nonlinear dispersion, and linear dispersion. [ABSTRACT FROM AUTHOR]

The article titled "The COVID-19 pandemic and its impact on environment: the case of the major cities in Pakistan" has been retracted by the publisher due to concerns regarding the peer review process, references, and the article's alignment with the journal's scope. The publisher, in consultation with the Editor-in-Chief, no longer has confidence in the article's results and conclusions. However, the author, Yousaf Ali Khan, disagrees with the retraction. Springer Nature, the publisher, remains neutral regarding jurisdictional claims and institutional affiliations. [Extracted from the article]

The article titled "Investigating the impact of renewable energy, international trade, tourism, and foreign direct investment on carbon emission in developing as well as developed countries" has been retracted by the publisher due to concerns regarding the peer review process, references, and the article's alignment with the journal's scope. The publisher, in consultation with the Editor-in-Chief, no longer has confidence in the results and conclusions of the article. The authors of the article disagree with this retraction. Springer Nature, the publisher, remains neutral regarding jurisdictional claims and institutional affiliations. [Extracted from the article]

Every wireless communication system comes with an innate problem of multipath propagation, which results in spreading the resultant symbols on a time scale and thus causes the symbols to overlap and end up in Inter-symbol Interference (ISI). The overall signal is distorted and the receiver is unable to recover the original signal. ISI from the signal must be removed and the signal must be brought back to its original form as it was sent or as close to it as possible; and process of equalization is used in all wireless communication system for this purpose. Two types of equalization processes are common in modern wireless communication systems. Training based equalization requires the sender block of communication system to constantly send a pilot/training signal in order to update the receiver about the original signal. The receiver removes the ISI and extracts the unadulterated signal. The second equalization process is called blind equalization and it does not require any pilot signal. The receiver only needs to know the type of constellation scheme used in modulation and then the original signal is extracted based on that information. In this paper we have thoroughly reviewed four equalization algorithms, two from each type of equalization for 16-QAM constellation and 64-QAM constellation. We came up with constellation diagrams for each equalization algorithm and comparison of BER, residual ISI and MSE for 16-QAM and 64-QAM is done through simulations. In case of LMS and RLS algorithm for 16 QAM, the performance of RLS gets slightly better than LMS at 6 dB, however, at around 12–14 dB and onwards the BER of RLS leads and there is a significantly better BER than LMS. In future, we will compare these algorithms in order to figure out the best algorithms for the current and upcoming 5G and 6G communication technologies. [ABSTRACT FROM AUTHOR]

Fiber-optic communication systems predominantly when employ in the nonlinear regime, generally do not perform truly as theory would speculate. This paper researched the theoretical model, power budget and transmission power penalties of the high capacity long haul optical network under the influence of nonlinear impairments. The presume model is affirmed using important nonlinear factors like effective area, launch power, received power, refractive index and length of the fiber. The power budget and transmission performance of the high capacity long haul optical network are analyzed on the basis of bit error rate and optical signal noise to ratio against launch power, length of the fiber, effective area and nonlinear refractive index. The simulation results manifest significant impact of nonlinear impairments on power budget and transmission power penalties of the high capacity long haul optical networks. [ABSTRACT FROM AUTHOR]

Conventional tree-based optical code division multiple access (OCDMA) systems do not provide any protection between optical line terminal and optical network units. This makes the entire OCDMA system significantly vulnerable to failures. This paper proposes a novel dual-ring spectral amplitude coding (SAC) OCDMA system, which consists of a single ring at the feeder level and two semi-rings at the distribution level. Analysis shows that the proposed system immediately detects and restores the flow of affected traffic and ensures survivability of the entire network. Moreover, comparison of the proposed system with exiting protection schemes shows that the proposed dual-ring SAC-OCDMA system provides desirable availability, 99.9995%, with minimum expenditure through simple architecture and simultaneous protection against failures at both feeder and distribution rings. [ABSTRACT FROM AUTHOR]

Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The original article can be found online at https://doi.org/10.1007/s11356-022-20781-2. B Correction to: Environmental Science and Pollution Research b https://doi.org/10.1007/s11356-022-20781-2 The correct assigned Author affiliations is revised in the original published proof. [Extracted from the article]

We propose the single feeder fiber architecture for wavelength division multiplexing passive optical network (WDM-PON) based on directly modulated chirp managed laser (CML). The downlink (DL) signal output from the laser is converted to return-to-zero (RZ) differential phase shift signal using a pulse carver. The downstream signal is reused as a carrier for the upstream using intensity modulation technique. Simulation results show the error-free performance at symmetric data rate of 10 Gbit/s per channel with negligible power penalty and improved receiver sensitivity for the uplink (UL), over 25 km standard single-mode fiber (SSMF). A low-cost and reduced circuitry network design is implemented on a single feeder fiber with the elimination of differential encoder and one external modulator. [ABSTRACT FROM AUTHOR]

We propose an arrayed waveguide grating (AWG)-based 10 Gbit/s per channel full duplex wavelength division multiplexing passive optical network (WDM-PON). A chirp managed directly modulated laser with return-to-zero (RZ) differential phase shift keying (DPSK) modulation technique is utilized for downlink (DL) direction, and then the downlink signal is re-modulated for the uplink (UL) direction using intensity modulation technique with the data rate of 10 Gbit/s per channel. A successful WDM-PON transmission operation with the data rate of 10 Gbit/s per channel over a distance of 25 km without any optical amplification or dispersion compensation is demonstrated with low power penalty. [ABSTRACT FROM AUTHOR]

The performance of colorless wavelength-division multiplexed passive optical network (WDM-PON) systems suffers from the transmission impairments mainly due to Rayleigh backscattering (RB). In this paper, we propose and demonstrate a single fiber colorless WDM-PON which enhances the tolerance to RB induced noise. The high extinction ratio in both return-to-zero (RZ)-shaped differential phase shift keying (DPSK) downstream (DS) data signal and intensity-remodulated upstream (US) data signal helps to improve the tolerance to RB induced noise. Simulation results show that downstream and upstream signals can achieve error-free performance at 10 Gbit/s with negligible penalty and improve the tolerance to RB induced noise over 25 km standard single-mode fiber. [ABSTRACT FROM AUTHOR]

We experimentally demonstrate and analyze a 10 Gbit/s full duplex wavelength division multiplexing passive optical network (WDM-PON) system. A non-return-to-zero differential phase shift keying (NRZ-DPSK) modulation technique is first utilized for downlink direction, and then the downlink signal is re-modulated for the uplink direction using intensity modulation technique of on-off keying (OOK) with a data rate of 10 Gbit/s per channel. An effective colorless WDM-PON full duplex transmission system is achieved for the data rate of 10 Gbit/s per channel with a channel spacing of 60 GHz over the distance of 25 km with low power penalty. [ABSTRACT FROM AUTHOR]

This paper investigates how to reduce the cost of wavelength division multiplexing passive optical network (WDMPON) by comparing the transmission performance of bidirectional single feeder fiber and dual feeder fiber. Comparison is performed on the basis of power budgeting and cost of both arrangements. Simulation results using Optisystem show that the performance of a single feeder fiber is almost equivalent to that of a dual feeder fiber. Therefore, the single feeder fiber WDM-PON can efficiently replace the dual feeder fiber WDM-PON with the minimum deterioration in system performance and reduction in cost. [ABSTRACT FROM AUTHOR]