Passive Q-switched and Mode-locked Fiber Lasers Using Carbon-based Saturable Absorbers

This chapter aims to familiarize readers with general knowledge of passive Q-switched and mode-locked fiber lasers. It emphasizes on carbon-based saturable absorbers, namely graphene and carbon nanotubes (CNTs); their unique electronic band structures and optical characteristics. The methods of incorporating these carbon-based saturable absorbers into fiber laser cavity will also be discussed. Lastly, several examples of experiments where carbon-based saturable absorbers were used in generating passive Q-switched and mode-locked fiber lasers are demonstrated

Gene expression of Anx3 in Pb-treated Nicotiana tabacum using a real-time RT-PCR

Lead (Pb) is one of the highly persistent, toxic, and widely distributed heavy metal pollutants in the environment. This heavy metal has a tendency to enter human food chain, thus affecting public health. One effective way to remove heavy metals pollutant is by using plants, a technology known as phytoremediation. One such plant that is routinely employed as an experimental model for such studies is Nicotiana tabacum. As tobacco plants are not generally consumed by herbivores, it minimizes the possibility of Pb from entering food chain. A number of studies suggest that annexins, a calcium-binding protein, does play a role in plant stress response. The expression of annexin gene in plants appeared to be regulated by tissue-specific developmental and environmental signal. A vacuole-associated annexin from N. tabacum, Anx3, was investigated, to observe the involvement of this gene in Pb-induced stress. Reverse transcription following quantitative real-time 0olymerase chain reaction (qRT-PCR) is a useful analysis to study gene expression. In this analysis, a reference gene that acts as internal control (housekeeping gene) is routinely employed for normalization of qRT-PCR against the target gene (Anx3). The candidate reference genes, L25, EF-1α, and Ntubc2, were evaluated using suitable primer pairs in order to select the most stable reference gene for normalization of qRT-PCR in this study. Using geNorm, NormFinder, and BestKeeper programs, the most suitable reference gene identified in this study was L25. The relative quantification of Anx3 gene expression normalizing against L25 was accomplished by REST software. The expression level of Anx3 in Pb-treated N. tabacum was upregulated by 2.2-fold (p < 0.05). The experimental methods used and the participation of Anx3 in defense against Pb stress will be discussed

S-band Q-switched fiber laser using MoSe2 saturable absorber

A passively Q-switched S-band fiber laser using Molybdenum Diselenide (MoSe2) saturable absorber (SA) is proposed and demonstrated. The SA is fabricated by depositing MoSe2 onto two fiber ferrules using the drop-cast method before heating and connecting the two fiber ferrules to form the SA. The passively Q-switched fiber laser designed using the MoSe2 SA has an operational range of 1491.0–1502.0 nm. The output pulse train has a pulse-width ranging from 2.0 μs to 1.0 μs and corresponding repetition rate of between 34.5 kHz and 90 kHz with increasing pump powers, as well as a signal-to-noise of about 35.97 dB. The peak performance of the proposed laser is between 1480.0 and 1490.0 nm, corresponding to the first peak gain region with the S-band

Determination Of Had Kifayah Zakat Among Pre-Graduate Students at Universiti Sains Islam Malaysia (Usim)

This research was supported by Pusat Wakaf dan Zakat, Universiti Sains Islam Malaysia under grant no PPPI/KHAS_PWZ/FSU/051007/15319.Had Kifayah refers to a minimum basic necessity rate set based on the current cost of living. The objective of this paper is to determine the current Had Kifayah for asnaf candidates focusing more on USIM Pre-Graduate students as the target group. The research method used are the qualitative and quantitative which apart from referring to existing writing and references, a survey was conducted to obtain the latest data from asnaf students through previous databases. The survey has been conducted via online instead one to one interview due to Covid-19 pandemic. Through a survey that covers aspects of student spending and income, the average of spending method has been used as per agreed with all team members to determine the Had Kifayah, in line with the method used by the state Islamic religious council as a reference. With the improvements made in the agreed calculation system, a more accurate calculation method has been developed and at the same time can help the process of proper distribution of zakat.Pusat Wakaf dan Zakat, Universiti Sains Islam Malaysia under grant no PPPI/KHAS_PWZ/FSU/051007/1531

Generation of microsecond ytterbium-doped fibre laser pulses using bismuth telluride thin film as saturable absorber

Bismuth telluride (Bi2Te3), a type of topological insulators, is currently in hot pursuit due to its unique physical properties. Therefore, this paper describes a simple Q-switched Ytterbium-doped fiber laser (YDFL) by using Bi2Te3 thin-film as saturable absorber. The few layers Bi2Te3 film was fabricated using optical deposition technique and subsequently, was used in an all-fiber, YDFL setup. As a result, a self-starting Q-switching pulses were first occurred when the laser pumping power reached 88.6 mW. As the pump power level increased, the observed pulses repetition rates had increased steadily from 17 to 29.63 kHz. Hence, this work demonstrated that Bi2Te3 thin-film can be used to successfully generate Q-switching pulses at 1-micron region and is well suited for many photonic applications operated at this wavelength region

Roles of human milk miRNAs and microbiota in infants gut: a systematic review

Early-life breastfeeding practice provides multiple advantages to infant subsequently contributing to significant short- as well as long-term positive health outcomes. The current notion suggested that in the first 1000 days of life, infant’s body is susceptible to external factors and highly inducible towards complex repertoire of components originated from mother’s milk. This condition permits diverse components of human breast milk ranging from microRNA and microbiome to larger size macronutrient to act by supplementing and supporting their under-developed body system in early life. Currently, the discoveries of milk miRNA as key effectors in multiple biological processes in different infant’s organs including gastrointestinal tract are growing rapidly. In addition, the perception on the translocation of bacteria from mother’s intestine to breast milk has given rise to the idea that these bacteria may as well dynamically transferred to the infant and provide protection to poor barrier integrity of their gut. Hence, the aim of this paper is to conduct a systematic review in order to collect, compile, and extract data related to human milk miRNAs and microbiota as well as their functions in infant’s gut following the relevant guidelines of Preferred Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA). A systematic search will be done on at least three databases such as Scopus, PubMed and Medline using relevant Medical Subject Headings (MESH) terms including human milk AND miRNA AND (microbiota OR microbiome) AND (infant OR child OR children) AND (gut OR intestine OR intestinal) from 2011 through 2021. From the databases, papers obtained will be sorted accordingly based on the objective, and inclusion and exclusion criteria and subject to Crowe Critical Appraisal Tool (CCAT) to further assess and ensure the quality, validity and eligibility of the research papers before reviewing thoroughly. This study is expected to provide a comprehensive presentation and information on the types of miRNAs and microbial species as well as their roles, functions and importance in boosting the system within infant’s gut. In depth, the miRNAs that capable of inducing genetic expression of their target genes or regulate particular important signalling pathways that would be beneficial in enhancing the immune system within infant’s gut may be presented in this study. Similarly, for some beneficial microbial species in the gut such as Lactobacilli with unique mechanisms and mode of actions in preventing the colonization of pathogenic bacterial within infant’s gastrointestinal tract and reduce clinical infection

Specific microRNAs among milk siblings: an epigenetics approach towards understanding the basis of milk kinship

Milk kinship is an Islamic belief described as a relationship established when infants receive breast milk from non-biological mothers. This form of kinship is said to bear a very close resemblance to blood relation whereby the recipients’ infants are regarded as milk siblings to the biological children of the breastfeeding mother. Any future marriage between these individuals is forbidden likewise between the recipient infant and the nursing mother herself as they are thought to have a form of consanguinity. The consanguinity formed by virtue of milk sharing might be due to the composition of human breast milk, especially milk microRNAs that are responsible for the epigenetic modulation of gene expression. miRNAs can regulate gene expression by modulating genome-wide epigenetic status of genes, and similarly-shared genes might be the basis that has led to milk kinship formation. Thus, the objective of the present study is to identify potential lactationspecific miRNAs that are similarly shared among milk siblings and their nursing mothers. The study began with molecular extraction of milk RNA from the nursing mothers and cell-free plasma RNA from all milk siblings and their nursing mothers. The RNAs extracted from both sample types were further analyzed using NanoString nCounter® miRNA Panel Analysis (NanoString Technologies, Seattle, WA) to measure the abundance of individual miRNAs biomarkers present within the samples. This study is expected to provide scientific explanation that could divulge the secrets behind milk kinship establishment with thorough presentation on the lactation-specific miRNAs shared between milk siblings. Hence, the way for future research would be paved, making the development of milk kinship identification tool possible

Specific MicroRNAs among milk siblings: an epigenetics approach towards understanding the basis of milk kinship

Introduction: Milk kinship is an Islamic belief described as a relationship established when infants receive breast milk from non-biological mothers. This form of kinship is said to bear a very close resemblance to blood relation whereby the recipients’ infants are regarded as milk siblings to the biological children of the breastfeeding mother. Any future marriage between these individuals is forbidden likewise between the recipient infant and the nursing mother herself as they are thought to have a form of consanguinity. The consanguinity formed by virtue of milk sharing might be due to the composition of human breast milk, especially milk microRNAs that are responsible for the epigenetic modulation of gene expression. miRNAs can regulate gene expression by modulating genome-wide epigenetic status of genes, and similarly-shared genes might be the basis that has led to milk kinship formation. Thus, the objective of the present study is to identify potential lactation-specific miRNAs that are similarly shared among milk siblings and their nursing mothers. Methods: The study began with molecular extraction of milk RNA from the nursing mothers and cell-free plasma RNA from all milk siblings and their nursing mothers. The RNAs extracted from both sample types were further analyzed using NanoString nCounter® miRNA Panel Analysis (NanoString Technologies, Seattle, WA) to measure the abundance of individual miRNAs biomarkers present within the samples. Expected Outcomes: This study is expected to provide scientific explanation that could divulge the secrets behind milk kinship establishment with thorough presentation on the lactation-specific miRNAs shared between milk siblings. Hence, the way for future research would be paved, making the development of milk kinship identification tool possible

Scleractinian coral (Cnidaria, Hexacorallia, Scleractinia) diversity of the Mersing Islands, Peninsular Malaysia

We present a comprehensive checklist of scleractinian (hard) corals for the Mersing Islands, Malaysia based on surveys conducted at 24 reefs across protected and unprotected marine areas. A total of 261 species of corals from 16 families and one incertae sedis (Pachyseris spp.) were recorded, along with ten records that are new for the east coast of Peninsular Malaysia. Compared against the IUCN Red List, 46.7% of coral species found in the Mersing Islands were of Least Concern (LC), 29.5% as Near Threatened (NT) and 16.4% Vulnerable (V). Only one recorded species, Pectinia maxima (Moll & Best, 1984), was listed as Endangered (EN). Baseline species diversity data are essential for the monitoring and management of marine biodiversity, especially within marine protected areas. With both protected and unprotected coral reef areas in the vicinity of the widely scattered Mersing Islands, the diversity and distribution of coral species can be used as the basis for area-based conservation and management strategies. The diversity and abundance of scleractinian corals of each island or area should be surveyed periodically to ensure the appropriate level of protection is afforded to retain scleractinian biodiversity in this region

A Fiber Bragg Grating—Bimetal Temperature Sensor for Solar Panel Inverters

This paper reports the design, characterization and implementation of a Fiber Bragg Grating (FBG)-based temperature sensor for an Insulted-Gate Bipolar Transistor (IGBT) in a solar panel inverter. The FBG is bonded to the higher Coefficient of Thermal Expansion (CTE) side of a bimetallic strip to increase its sensitivity. Characterization results show a linear relationship between increasing temperature and the wavelength shift. It is found that the sensitivity of the sensor can be categorized into three characterization temperature regions between 26 °C and 90 °C. The region from 41 °C to 90 °C shows the highest sensitivity, with a value of 14 pm/°C. A new empirical model that considers both temperature and strain effects has been developed for the sensor. Finally, the FBG-bimetal temperature sensor is placed in a solar panel inverter and results confirm that it can be used for real-time monitoring of the IGBT temperature