bluuebunny/crossref_metadata_2025 huggingface dataset:
Consequences of assisted reproductive technologies for offspring function in cattle
Authors: Siqueira Luiz G. , Silva Marcos V. G. , Panetto João C. , Viana João H.
Published: December 2019

Abnormal fetuses, neonates and adult offspring derived by assisted reproductive technologies (ART) have been reported in humans, rodents and domestic animals. The use of ART has also been associated with an increased likelihood of certain adult diseases. These abnormalities may arise as a result of an excess of or missing maternally derived molecules during invitro culture, because the invitro environment is artificial and suboptimal for embryo development. Nonetheless, the success of ART in overcoming infertility or improving livestock genetics is undeniable. Limitations of invitro embryo production (IVEP) in cattle include lower rates of the establishment and maintenance of pregnancy and an increased incidence of neonatal morbidity and mortality. Moreover, recent studies demonstrated long-term effects of IVEP in cattle, including increased postnatal mortality, altered growth and a slight reduction in the performance of adult dairy cows. This review addresses the effects of an altered preimplantation environment on embryo and fetal programming and offspring development. We discuss cellular and molecular responses of the embryo to the maternal environment, how ART may disturb programming, the possible role of epigenetic effects as a mechanism for altered phenotypes and long-term effects of ART that manifest in postnatal life.
Role of extracellular vesicles during oocyte maturation and early embryo development
Authors: de Ávila A. C. F. C. M. , da Silveira J. C.
Published: December 2019

The follicle is a dynamic microenvironment in the ovary where the oocyte develops. Intercellular communication between somatic cells and the oocyte inside the follicle is essential to generate a competent gamete. Extracellular vesicles are nanoparticles secreted by cells that mediate cell-to-cell communication in the follicle microenvironment and can be obtained from the follicular fluid. These extracellular vesicles have been studied as biomarkers and supplementation tools to mimic physiological conditions during assisted reproductive techniques because they are vehicles of bioactive molecules. Therefore, this paper reviews the importance of changes in the ovarian follicle and the effects of extracellular vesicles from follicular fluid during oocyte maturation and early embryo development. Finally, we propose that is important to consider the source of the extracellular vesicles to improve diagnostic methods and to increase invitro embryo production.
115 Invivo confocal laser endomicroscopy visualisation of fresh and frozen bull spermatozoa in the genital tract of dairy heifers
Authors: Richard C. , Druart X. , Saint-Beuve T. , Gelin V. , Laffont L. , Ruffini S. , Ghazali S. , Saint-Dizier M. , Duranthon V. , Sandra O. , Grimard B. , Mauffre V.
Published: December 2019

Fertility in cattle includes the ability of the uterus to provide the appropriate environment for pregnancy success, including the transport of spermatozoa before fertilization. Confocal laser endomicroscopy technology (Cellvizio) has been previously used in small ruminants to visualise labelled spermatozoa invivo in the uterine horns of ewes (Druart et al. 2009 Reprod. 138, 15-53). Nevertheless, to the best of our knowledge, no invivo study has reported a live visual analysis of the behaviour of spermatozoa in the bovine uterus upon AI. The aim of this study was to develop an experimental procedure to label bull spermatozoa and to visualise their progression in the uterine horns of dairy cows, using Cellvizio and uterine cervix catheterization. Fresh ejaculated bull spermatozoa were double-labelled with octadecyl rhodamine B chloride and MitoTracker Green FM dyes before dilution and freezing processing. At each step of the process, semen quality was evaluated with a semen quality analyzer (SQA-V b, Medical Electronic System) and compared to nonlabelled bull reference semen. The specificity of the labelling was validated invitro. We also developed a specific device to insert the Cellvizio fibre probe into the genital tract, in order to image vagina, cervix, and uterine body, as well as the proximal, middle, and distal parts of the uterine horn, including the utero-tubal junction (UTJ), before and after AI with fresh and frozen labelled spermatozoa. Then, 10 heifers were oestrus synchronized. Video sequences were recorded at oestrus (n=5), just before AI, at the time of AI (7-12h after the onset of oestrus), 30 and 120min after AI, and 14 days after oestrus (n=5; luteal phase), to investigate the effect of the steroid-primed uterine environment on the distribution and progression of spermatozoa in the genital tract. Using our approach, labelled spermatozoa were detected (1) at the day of oestrus and 14 days after oestrus, (2) in the uterine body at the time of AI, (3) in various parts of the genital tract 30min after AI, and (4) in the UTJ, the cervix, and the vagina 120min after AI. In addition, labelling the spermatozoa did not alter the fertilizing capacity: 4 of the 5 oestrus females were pregnant at Day 35. Additionally, an IVF test showed a blastocyst rate of 45.8% for labelled semen vs. 39.4% for the control group (Carvalho et al. 2017 Reprod. 154, 695-710). In conclusion, our study provides a method to phenotype in situ the transport of spermatozoa in the genital tract of heifers. Further investigations are in progress to optimize video quality, to develop an algorithm for an automatic analysis (spermatozoa count, speed, and path) of the recorded sequences.
131 Genetic variants and haplotype combination in the bovine SH2B2 gene and their associations with molecular breeding for body size traits in Qinchuan cattle (Bos taurus)
Authors: Raza S. H. A. , Zan L.
Published: December 2019

The Src homology 2B 2 (SH2B2) gene regulates energy balance and body weight at least partially by enhancing Janus kinase-2 (JAK2)-mediated cytokine signalling, including leptin or GH signalling. Leptin is an adipose hormone that controls body weight. The objective of the current study was to evaluate the association between body measurement traits and SH2B2 gene polymorphisms. For this purpose, we selected four single-nucleotide polymorphisms (SNPs) in the SH2B2 gene, including two in intron 5 (A20545G and G20570A), one synonymous SNP (T20693C) in exon 6, and one in intron 8 (C24070A), and genotyped these through DNA sequencing in Qinchuan cattle. The general linear model (GLM) in SPSS 20.0 software (SPSS Inc.) was used for the association analysis between SNPs and selected traits of carcass quality. The SNPs in sample populations were in medium polymorphism level (0.250<pic<0.500). This association study indicated that the G20570A, T20693C, and C24070A were significantly (P<0.05) associated with body length (BL) and chest circumference (CC) in Qinchuan cattle. In addition, the H4H3 and H5H5 diplotype were associated with significantly (P=0.01) greater BL and rump length than was H4H2. Our investigation will not only extend understanding of genetic variations in the bovine SH2B2 gene but also provide useful information for marker-assisted selection in beef cattle breeding programs.
143 Stimulated glycolysis is able to maintain ATP levels and motility of bull spermatozoa submitted to mitochondrial depolarisation
Authors: Losano J. , Padín J. , Méndez-López I. , Angrimani D. , Montez N. , García A. , Barnabe V. , Nichi M.
Published: December 2019

Studies have reported the importance of mitochondria in sperm metabolism. However, for some species, glycolysis appears to be as essential as oxidative phosphorylation in sperm physiology. On the other hand, these mechanisms have not been fully elucidated for bovine spermatozoa. Therefore, the aim of this study was to evaluate the role of mitochondria and glycolysis in ATP synthesis and sperm kinetics of bovine spermatozoa. For this purpose, sperm from seven bovine epididymides (n=7) was collected and diluted to a concentration of 100×106 spermatozoamL−1 in Tyrode's albumin lactate pyruvate medium. Then, each sample was divided into 10 aliquots and evaluated in a 2×5 factorial design, with the first factor being the presence or absence of glucose (5mM) to stimulate glycolysis and the second factor being treatment with the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 0, 0.1, 0.3, 1, and 3 µM) to deplete mitochondrial ATP. Sperm samples were subjected to measurements of ATP levels using a luminescence technique (CellTiter-Glokit, Promega), with ATP levels measured in duplicate. In addition, sperm samples were subjected to computerised analysis of total and progressive motilities (ISAS, Proiser). Statistical analysis was performed using SAS (SAS Institute Inc.), where the interaction between the factors was analysed using PROC GLM and the comparison between groups was performed using means analysis of variance (least significant difference test). It was considered significant at 5%. Adenosine triphosphate was lower at FCCP concentrations of 0.3 µM (180.3±31.9nM), 1 µM (220.2±40.4nM), and 3 µM (272.3±70.4nM) than at 0 µM (control; 448.6±63.7nM) and 0.1 µM (422.4±41.5nM) in the absence of glucose. However, in the groups treated with FCCP supplemented with glucose, ATP concentrations did not differ among the groups (0 µM: 577.2±70.4 nM; 0.1 µM: 610.8±57.8 nM; 0.3 µM: 606.2±64.2 nM; 1 µM: 670.9±61.9 nM; 3 µM: 696.1±68.5nM). Additionally, total motility was lower in FCCP-treated groups without glucose supplementation. On the other hand, total motility increased in the groups treated with 0.3, 0.1, 1, and 3 µM FCCP supplemented with glucose. A similar effect was verified for progressive motility. Based on these results, we can suggest that glucose supplementation is able to maintain ATP levels and motility in bull sperm undergoing FCCP-induced mitochondrial depolarisation.
144 Serum testosterone profile in Marwari stallions and its relationship with testicular parameters, semen characteristics, reaction time, stallion age, bodyweight, and height
Authors: Chaudhary A. K. , Purohit G. N. , Mehta J. S. , Ravi S. K. , Talluri T. R.
Published: December 2019

The present study investigated the serum testosterone profile of Marwari stallions before and after exposure to a mare and the relationship of serum testosterone profile with scrotal circumference, semen characteristics, reaction time, stallion age, bodyweight, and height. Marwari stallions (n=9) of three age groups (2-4 years, n=3; 4-6 years, n=3; and 6+ years, n=3) were used in the study. Scrotal circumference, height, and bodyweight of each of the stallions were measured. Semen was collected from each stallion twice per week in the early-morning hours using an artificial vagina and a mare in oestrus. Six ejaculates were collected from each stallion for evaluation of various seminal parameters (semen volume, sperm concentration, and progressive sperm motility). Reaction time for each stallion was also recorded. At every alternate semen collection (first, third, and fifth collections), blood samples were taken 15min before exposure to the mare and just before the semen collection for serum testosterone hormone assay using a horse testosterone enzyme-linked immunosorbent assay kit. The data obtained were analysed statistically using SPSS ver. 20.0 (IBM Corp.). The results showed that mean testosterone concentration was significantly different (P ≤ 0.01) among the stallions and was significantly lower (P ≤ 0.01) in the stallions below 4 years of age. No significant difference in testosterone level was observed before and after exposure to a mare. A positive correlation was detected between testosterone and both scrotal circumference (P ≤ 0.05) and sperm concentration (P ≤ 0.05), whereas a negative correlation was observed with reaction time (P ≤ 0.01). It was concluded that exposure to a mare does not change the testosterone level in stallion blood and that there is a relationship of serum testosterone concentration with scrotal circumference, sperm concentration, reaction time, and age but not with height and bodyweight.
197 The use of photostimulation to enhance oocyte cytoplasmic maturation
Authors: Checura C. M. , Pratt S. L. , Campbell L. V. , Farmer K. , Loughlin G. , Mitchell M. , Sandford A. , Treske A. M. , Malter H.
Published: December 2019

Phototherapy uses monochromatic light from low-power lasers and light-emitting diodes (LEDs) to modulate biological processes. It has been proposed that the red-to-near infrared optical region (~600-1000nm) enhances cellular metabolic activity by activation of the mitochondrial respiratory chain. However, photostimulation induces the generation of oxide free radicals and could create oxidative stress in exposed cells. The main objective was to use photostimulation to affect the cumulus-oocyte complex metabolic state, aiming to enhance cytoplasmic maturation rates and subsequent embryonic development. A secondary objective was to determine the toxicity of the proposed photostimulation protocol. Abattoir-derived ovaries were used. All media was from IVF Biosciences (Falmouth, Cornwall, UK). Follicles 2 to 6mm in diameter were aspirated. Oocytes with compact cumulus and homogeneous cytoplasm were selected, and 50 oocytes/well were placed in invitro maturation medium (0h) and incubated at 38.5°C in 5% CO2 in air with high humidity in the presence (treatment=exposure for 2min to super-bright LED 1 and 2h after the beginning of maturation; LED wavelength of 660-665 nm; NTE30041; NTE Electronics Inc.) or absence (Control) of light. After maturation (22h), oocytes were split into two wells (25 oocytes/well) and subjected to IVF with semen from two different bulls for 18 to 20h. Cumulus cells were separated by vortexing, zygotes were placed in invitro culture medium, and incubated at 38.5°C in 5% CO2 in air with high humidity. Culture medium was renewed every 48h. Cleavage, morula, and blastocyst rates were recorded as a percentage of the number of oocytes subjected to IVF per treatment. The experiment was replicated 4 times. Statistical analysis was conducted using the Mixed procedure (SAS 9.4, SAS Institute Inc.) with repeated-measures and autoregressive covariance. The model's random effect was well within treatment. Fixed effects were bull, stage of development, and treatment. There was no difference (P=0.8) between treatments for any stage of development measured (cleavage: 76.4±2.7 vs. 74.8±4.1; morula: 36.1±4.8 vs. 35.9±5.8; blastocyst: 20.8±3.2 vs. 20.6±4.4 for control and treatment respectively; mean±s.e.). Sire affected development: bull 1 had a greater percentage (P<0.05) cleavage (82.9±0.02 vs. 68.3±0.02), morula (42.6±0.05 vs. 29.4±0.04), and blastocyst (27.8±0.04 vs. 13.6±0.01) development than bull 2. There was no treatment×bull interaction (P=0.9). In conclusion, there were no stimulatory or toxic effects of this preliminary photostimulation protocol. Further research is needed to develop an optimal protocol that shows a metabolic effect and, potentially, an enhancement of invitro cytoplasmic maturation rates and subsequent embryonic development.
81 Linoleic acid required for reduction of apoptosis through nuclear transcription factor-kappa B during pig embryo development
Authors: Lee D. , Choi K. , Oh J. , Kim S. , Lee M. , Cho M. , Lee C.
Published: December 2019

Recent studies suggest that endogenous and exogenous free fatty acids play various important roles in mammalian oocyte and pre-implantation embryo development. Among fatty acids, linoleic acid (LA) has been reported to affect the apoptosis pathway via nuclear transcription factor-kappa B (NF-κB). The transcription factor NF-κB is a key modulator of apoptosis in a variety of cell types, but to date, this specific function of NF-κB has not been demonstrated in porcine pre-implantation embryos. To examine the effect of linoleic acid on invitro-produced parthenogenetic pig embryos, we treated LA by concentration (0, 10, 25, 50, and 100 µM) to identify developmental rate, NF-κB expression, and mRNA level of apoptotic-related genes. In addition, the mechanism was confirmed by examining the protein and mRNA expression of NF-kb and c-jun by immunostaining and quantitative PCR at the blastocyst stage. Linoleic acid had a positive effect on embryo development without toxicity at a certain concentration (25 µM), but toxicity was confirmed at higher (50-100μM) concentrations. Furthermore, it was confirmed that the concentration of NF-κB increased as the treatment concentration of LA increased, which was found to increase even at the concentration at which embryo development decreased. Previous studies have shown that the NF-κB pathway is involved in regulating anti- and pro-apoptotic gene expression. We also investigated the effects of LA on anti- (Bcl-xL, Mcl-1) and pro- (BAX1, TP53, Caspase3) apoptotic genes and NF-κB activation-related genes (RelA, JNK1, JNK2, IL-6) in porcine embryos. We have found that down-regulation of pro-apoptotic gene expression occurs in the LA-treated group. It was also found that Bcl-xL, one of the anti-apoptotic genes, was not affected by LA, which appears to be an effect of IL-6. In contrast, Mcl-1, an anti-apoptotic gene known not to be affected by IL-6, was found to have increased expression mRNA level in LA-treated pig embryos. Furthermore, through double-staining of apoptosis and immunocytochemistry, as the concentration of NF-kB level increases, the nuclear translocation of c-jun, the protein of which was also related with apoptosis, increased gradually depending on the LA concentration. These data could support that porcine embryo can use exogenous LA as a metabolic energy source. The data also demonstrate the important role of NF-kB in porcine early embryo development.
Support was provided by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through the Development of High Value-Added Food Technology program funded by the Ministry of Agriculture, Food and Rural Affairs (MAFRA, 118042-03-1-HD020).
83 Validation of propidium iodide dye for live-dead staining of bovine blastocysts: Preliminary results
Authors: Hellmold H. , Teuteberg D. , Tetens J. , Blaschka C.
Published: December 2019

A widely used criterion routine laboratories utilise for the selection and classification of oocytes and embryos is morphological appearance. In order to make an objective validation of produced embryos, it is necessary to have a method that can help to distinguish viable cells. One simple and easy-to-perform method is the live-dead staining protocol. Usually, ethidium homodimer (EthD) is used to stain the dead cells, in conjunction with Hoechst 33342 for total cell numbers (Stinshoff et al. 2011). However, EthD is a harmful, toxic, and expensive staining dye. Therefore, the aim of this study was to evaluate propidium iodide (PI) as a viable alternative to EthD. To assess the suitability of PI, groups of 20 cumulus-oocyte complexes were collected from abattoir-derived bovine ovaries and matured in tissue culture medium containing bovine serum albumin and equine chorionic gonadotropin/human chorionic gonadotropin for 24h with 5% CO2. The cumulus-oocyte complexes were then fertilised in Fert-TALP (Tyrode's albumin lactate pyruvate) for 19h with 5% CO2 and finally cultured (n=968) in SOFaa (synthetic oviductal fluid with amino acids) with 5% CO2 and 5% O2 with all steps being performed at 39°C. The development rate on Day 8 was on average 25.4%. Expanded Day 8 blastocysts were then utilised to validate the two different staining protocols. Expanded blastocysts were collected from culture drops and washed in PBS containing polyvinyl alcohol. The blastocysts were then stained with the selective dye and finally counterstained to determine live and dead cells. Four alternative parameters were evaluated: (A) PI 1:5 for 15min, (B) PI 1:10 for 15min, (C) PI 1:5 for 5min, and (D) EthD 1:10 for 15min (control). Counterstaining with Hoechst 33342 was performed for 3min in all groups tested. A minimum number of 10 replicate stainings ((A) n=13, (B) n=13, (C) n=12, (D) n=10) was carried out. The evaluation was performed under a fluorescence microscope (Nikon Eclipse Ci) with the NIS-Elements imaging software (Nikon). The statistical analysis was assessed using R. All data were analysed for normal distribution using a Shapiro-Wilk test. Evaluation of the data was made through the application of t-tests. The total cell numbers observed were in the known range for expanded blastocysts: (A) 106.3±15.3, (B) 109.5±18.8, (C) 119.3±15.0, and (D) 113.1±21.8. The number of dead cells did not differ significantly from the control: (A) 13.3±7.7, (B) 8.5±5.0, (C) 11.8±8.7, and (D) 9.3±2.3. The study indicates that PI could be used as an adequate alternative for EthD. Furthermore, it is possible that the concentration or the incubation time could be reduced to generate similar results to EthD. Further replicates are currently being examined in order to corroborate these results.
We gratefully acknowledge our colleague M. Vopel.
86 Effect of invitro culture conditions on mitochondria functions in mouse embryos
Authors: Czernik M. , Winiarczyk D. , Sampino S. , Greda P. , Modlinski J. A. , Loi P.
Published: December 2019

Mitochondria provide the energy for oocyte maturation, fertilisation, and embryo formation via oxidative phosphorylation. Consequently, any adverse influence on mitochondrial function may negatively affect the development of pre-implantation embryos especially because there is no mitochondrial DNA (mtDNA) replication until post-implantation. Studies in the field of mitochondrial dynamics have identified an intriguing link between energy demand/supply balance and mitochondrial architecture, which may suggest that inappropriate culture conditions may inhibit mitochondrial functions, which may negatively affect embryo development. We wanted to check whether invitro culture (IVC) conditions of mouse embryos affect mitochondrial functionality. The IVC as well as naturally matted (NM) mouse embryos at the 2-cell and blastocyst stage were subjected to mitochondrial analysis (distribution, organisation, and mitochondrial membrane potential), and expression of mRNA and proteins involved in regulation of mitochondria functions, as well as number of mtDNA copies, were evaluated. Significance level was set at 0.05. We observed that the mitochondria in 2-cell IVC embryos were less numerous and localised mainly in the pericortical region of the cytoplasm, whereas mitochondria in NM embryos were numerous and homogeneously distributed in both blastomeres. Drastic differences were observed in blastocysts. Mitochondria in the IVC group were fragmented, rounded, and aggregated mainly in the perinuclear region of the cells, whereas mitochondria of NM blastocysts were numerous and created an elongated mitochondrial network along the cells. Time-lapse analysis showed reduced mitochondrial and mitochondrial membrane activity in IVC blastocysts. Moreover, our results indicate the IVC group had reduced mRNA expression of mitofusin 1, mitofusin 2, and optic atrophy 1 responsible for mitochondrial fusion. Additionally, mtDNA copy number for IVC blastocysts (398 887.45±30 608.65) was significantly lower than that of NM blastocysts (593 367.12±66 540.32; P<0.02). Furthermore, no significant differences were found in mtDNA copy number of IVC 2-cell embryos when compared with NM embryos. The results obtained clearly showed that IVC conditions affect proper mitochondrial functionality and hence embryo development.
97 Loss of aggregation capacity of bovine invitro-produced embryos and blastocyst-derived trophoblasts from Day 6 of development
Authors: Alberio V. , Yauri Felipe M. , Salamone D.
Published: December 2019

Embryo aggregation consists of placing more than one zona-free (ZF) embryo in contact during development to obtain a unique structure. It has been reported in different species that aggregated cloned embryos show certain benefits compared with nonaggregated embryos. One way to obtain these benefits in IVF embryos would be to generate a transient chimera by the introduction of trophoblastic cells. Bovine trophoblastic cells can be obtained by embryo bisection of blastocysts, cutting asymmetrically to use trophoblasts (Tr) for aggregation and leaving aside the portion that contains the inner cell mass (ICM). Taking all this into account, the objectives of this work are to study the aggregation of Tr at different days of development and to determine the appropriate time of aggregation. To this aim, cumulus-oocyte complexes (COCs) collected from slaughterhouse ovaries were matured in tissue culture medium 199 containing 10% fetal bovine serum, 10µgmL−1 FSH, 0.3mM sodium pyruvate, 100mM cysteamine and 2% antibiotic-antimycotic for 24h, at 6.5% CO2 in humidified air and 38.5°C. We performed IVF with 16×106 spermatozoa per mL for 5h. Afterwards, presumptive zygotes were cultured in synthetic oviductal fluid (SOF) for 7 days in a humidified atmosphere at 38.5°C, 5% O2, 5% CO2, and 90% N2. In Experiment 1, embryo bisection of Day 7 blastocysts was performed manually under stereoscopic observation with a microblade to obtain Tr. These were aggregated, with the bisected part containing the ICM (n=22) or with ZF embryos of Days 4 (n=23), 5(n=25), or 6 (n=22) and blastocysts (n=25), and placed in microwells in a 100-μL SOF drop covered by mineral oil (Gambini et al. 2012 Biol. Reprod. 87, 15; https://doi.org/10.1095/biolreprod.112.098855). In Experiment 2, ZF synchronous whole embryos were aggregated in microwells at different developmental days: Day 3 (n=18), 4 (n=18), 5 (n=47), 6 (n=48), and 7 (n=45). In both experiments, aggregation was assessed at Day 8. In Experiment 1, no aggregation was observed between the Tr and the embryos or the bisected ICM. Experiment 2 showed embryo aggregation on Days 3 (55%), 4 (27%), and 5 (61%), whereas on Days 6 and 7 no aggregation was observed. According to these results, we can conclude that, in our culture conditions, Tr obtained by blastocyst bisection have no capacity for aggregation. Day 6 and 7 whole ZF embryos also do not aggregate. As a general conclusion, there is a period from Days 0-5 of the invitro development of bovine embryos in which aggregation is possible. Aggregation of blastocyst-derived Tr to cloned or high-value IVF embryos, aiming for quality improvement, is not an effective strategy.
The politicization of religious communities: effects on intergroup differentiation / La politización de las comunidades religiosas: los efectos en la diferenciación intergrupal
Authors: Krys Sabrina , Simon Bernd , Reininger Michael , Brause Ann-Christin , Galeão-Silva Luis-Guilherme
Published: December 2019

The article reports two studies in which we examined how the politicization of religious communities influences both affective and cognitive intergroup differentiation. In Study 1, we used a longitudinal research design and observed that politicization among members of Protestant communities in Germany negatively affected their feelings towards and perceptions of commonalities with homosexuals and Muslims. In Study 2, we used a cross-sectional design and replicated the results with members of Protestant communities in Brazil as research participants and homosexuals and adherents of Afro-Brazilian religions as target groups. However, unlike politicization, which revolves around demands for greater support directed at the larger society, community solidarity, which focused on engagement for one’s community, was unrelated to affective intergroup differentiation and even negatively related to cognitive intergroup differentiation, especially in the German context.
Relationship between transformational leadership, affective commitment and turnover intention of workers in a multinational company / La relación entre liderazgo transformacional, compromiso afectivo e intención de rotación de los trabajadores en una compañía internacional
Authors: Mañas-Rodríguez Miguel-Ángel , Díaz-Fúnez Pedro-Antonio , Llopis-Marín Juan , Nieto-Escámez Francisco , Salvador-Ferrer Carmen
Published: December 2019

Transformational leadership is the key to achieving excellent organizational outcomes. Some authors point out that the existence of a transformational leader reduces the likelihood that their employees leave the company. In addition, the intention of abandonment is also reduced when there is a high affective commitment. In this sense, the goal of our work is to know if there is a link between transformational leadership and turnover intention, and also to analyse if such a relationship is mediated by affective commitment. The study was performed in a sample of 706 employees in a multinational company. The scales used were the transformational leadership questionnaire, the affective engagement questionnaire (ISA) and the turnover intention scale. The results show that there is a statistically significant relationship between transformational leadership and turnover intention. We also found that this relationship is mediated by affective commitment.
Microsecond pulse erbium-doped fiber laser using WS2 deposited on D-shaped fiber fabricated by polishing wheel technique
Authors: Jafry A A A , Kasim N , Munajat Y , Yusoff R A M , Harun S W
Published: December 2019

We demonstrate a stable Q-switching pulse train output centered at 1561 nm by implementing D-shaped fiber deposited tungsten disulphide (WS2) as a saturable absorber in erbium-doped fiber laser. D-shaped fiber was fabricated using a polishing wheel technique with two stages polishing. Proposed Q-switched EDFL generates a maximum repetition rate of 47.28 kHz at a pulse duration of 5.4 us. Under pump power of 104.6 mW, the laser consumed pulse energy of 99.4 nJ with an output power of 4.7 mW. This WS2-D-shaped SA is excellence for the production of Q-switched laser source.
Photochemical reduction of carbonyl group of polyimide by 450 nm diode laser
Authors: Roslan M S , Kamarudin H , Sharip N , Zin A F M , Muhamad A , Agam A , Nayan N , Tariq U
Published: December 2019

In this article, we report directly patterned graphene nanoribbons by laser irradiation. The transformation of polymer into graphene nanostructure by breaking oxygen bonding and followed by graphitization of carbon atoms has been employed by using the photochemical technique. The scalable and fast growth of graphene nanoribbon was carried out by irradiating 450 nm diode laser directly onto polyimide polymer. Patterned graphene was characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Field emission scanning electron microscopy (FESEM). The ability of polyimide to absorb laser light in the near-ultraviolet region contribute to the tailoring of graphene nanoribbon which reduces oxygen bonding as well as paves way for the development of optoelectronics applications.
A study of relative humidity sensor on micro-ball resonator
Authors: Ali U U M , Johari M A M , Jusoh Z , Rahman H A , Harun S W
Published: December 2019

We investigate the use of a class of whispering gallery mode optical resonators, namely, optical micro-ball resonator (MBR) as a relative humidity (RH) sensor. The MBR is fabricated using fusion splicer at the tip of standard optical fibers; single-mode fibers (SMF-28). The MBR is then optically excited by using an 8?? optical microfiber and was found to have a Q-factor of >105. The MBR was then employed as a humidity sensor with an RH range of between 40% to 100%. The MBR RH sensor was found to have a sensitivity 0.284 dB/%, linearity >90% and is superior to the bare microfiber in all measured parameters. The MBR RH sensor was also found to have good repeatability and stability compared to bare microfiber.
PMMA microball resonator for formaldehyde liquid sensing
Authors: Sharif M M , Rahim H R A , Johari M A M , Abdul Khudus M I M , Harun S W
Published: December 2019

This experiment reports the fabrication of the Polymethyl Methaclyrate (PMMA) Microball Resonator (MBlR) as a liquid sensor tested on various level of concentration of the Formaldedhye liquid. The PMMA MBlR is fabricated via the “dipped and twirl” method to create the sphere-shaped ball with diameter Db = 320um. The MBlR is then optically excited using a 9|am PMMA microfiber and was found to have a Q Factor of >104. The MBlR was then employed as a liquid sensor with the level percentage range between 0% to 4% of Formaldehyde liquid and the performance is compared with a non MBlR microfiber. The MBlR sensor was found to have a sensitivity of 6.94 dBm/%, linearity >90% and P-value of more than 105. The PMMA MBlR liquid sensor was also found to have good repeatability and stability over a period of 60 seconds.
Optical comb filter generation in micro cavity employing Zinc Oxide based film
Authors: Burhanuddin H M , Zuikafly S N F , Ibrahim A A , Ambran S , Mikami O , Fujikawa C , Ahmad F
Published: December 2019

Optical comb filter generation was proposed and experimentally demonstrated by using Fabry-Perot interferometer in micro cavity. The change of length of Fabry-Perot interferometer modifies the interference pattern with the adjusted length is from 0 um to 350 nm. The parameter of the generated comb such as free spectral range, extinction ratio, quality factor and finesse was recorded with and without Zinc Oxide based film (nano powder and nano particles). The stable comb filter was generated with a length of 100 um for both Zin Oxide-based film and 150 um for the uncoated mirror. At the maximum length of 350 nm, Zinc Oxide nano particles film generates most stable optical comb filter with free spectral range, extinction ratio, quality factor and finesse of, 3 nm, 8 dB, 1298 and 2.5, respectively.
Q-switched erbium-doped fiber laser employing gold thin film saturable absorber
Authors: Yuzaile Y R , Zakaria Z , Zalkepali N U H H , Awang N A , Latif A A , A H AH , Nik Mahmud N N H E
Published: December 2019

This research demonstrates an erbium-doped fiber laser (EDFL) which was passively Q-switched by gold thin film saturable absorber (SA). A very simple technique was used to fabricate the SA, in which the gold was directly deposited on the fiber end face through DC magnetron sputtering at 120 mA of sputtering current. The SA was then inserted into the single ring cavity and achieved Q-switching at a threshold pump power of 38.8 mW. By gradually increasing the pump power from 38.8 mW to 119.3 mW, the repetition rate increases from 11.34 kHz to 21.72 kHz. Meanwhile, the pulse duration decreases from 13.91 us to 7.44 us. The maximum achievable pulse energy was 13.28 nJ. This research further expands the application of gold thin film S A to the field of Q-switched pulsed fiber laser.
Influence of concentration on the geometry of ZnO nanostructures prepared by chemical bath deposition
Authors: Rosli N , Halim M M , Hashim M R , Maryam W
Published: December 2019

Zinc Oxide (ZnO) nanostructures such as nanorods (NRs), nanowalls (NWs) and nanoflakes (NFs) were successfully grown on a glass substrate via chemical bath deposition (CBD) method by varying solutions concentration (0.01 M, 0.05 M, 0.10 M, 0.15 M, 0.20 M and 0.25 M). Effect of CBD concentration on the growth and morphology of ZnO nanostructures are dignified. The structural and optical properties of ZnO NRs, NWs, and NFs were investigated by Field Emission Scanning Electron Microscope (FESEM), energy-dispersive X-ray (EDX), X-Ray Diffraction (XRD), and UV-Visible (UV-Vis) analyses. Results reveal that as the CBD concentration increases, FESEM images showed differ top-down morphology of ZnO nanostructures from NRs, NWs to NFs. Likewise, the alignment of ZnO cross-section evolved from randomly oriented to vertically oriented. As revealed by EDX, the stoichiometric ratio of Zn:O were mostly towards 1:1. From XRD analyses, the preferred structure was wurtzite hexagonal with c-axis orientation along (002) plane. The UV-Vis analysis exposed the optical band gap energy closes to the standard energy gap value of ZnO at 3.37 eV. Thus, this work introduces a variable geometry of ZnO nanostructures (NRs, NWs, and NFs) grown on glass with high structural and optical quality as standard ZnO. The fabricated materials are potential candidates for investigating random lasing in ZnO from different structural geometry.
Tunable passively Q-switched fiber laser of graphite flakes saturable absorber
Authors: Mahmud Nik N H E N , Esa Fahmiruddin , Awang Noor A , Zakaria Zahariah , Yuzaile Yushazlina R , Zalkepali Noor U H H
Published: December 2019

This study demonstrated the performance of a passively Q-switched fiber laser by using graphite flakes at different EDF absorption which are EDF 1 and EDF 2 at 5.09 dB/m and 7.28 dB/m, respectively. The system is designed as a single ring cavity by employing a graphite flakes saturable absorber (SA) with 23.82% of saturable absorption. The experimental result shows that a wide-band tunable cover from 1544 nm to 1560 nm and 1552 nm to 1570 nm for EDF 1 and EDF 2 respectively. The EDF 2 is the best gain medium due to the conventional wavelength band at C band and L band region.
A study on relative humidity sensors using PVA and PMMA coating
Authors: Harith Zuraidah , Adnan Abdullah Zain Huda , Batumalay Malathy , Wadi Harun Sulaiman
Published: December 2019

Simple relative humidity sensors are demonstrated using tapered silica microfibers. The silica microfibers are tapered using flame brushing method to reduce the fiber’s waist diameter from 128 micrometers to 2.6 micrometers. The tapered silica microfibers were then coated using polyvinyl acetate (PVA) and polymethyl methacrylate (PMMA) before it was used to sense the relative humidity. The tapered silica microfiber coated with PVA performed better compared to tapered silica microfiber coated using PMMA. The tapered silica microfiber with PVA based sensor has better sensitivity of 0.3023 dB/RH%.
Q-switched erbium-doped fiber lasers based on copper nanoparticles saturable absorber
Authors: Ismail E I , Ahmad F , Ambran S , Latiff A A , Harun S W
Published: December 2019

We reported a generation of passively Q-switching pulses in an erbium-doped fiber laser by exploiting copper nanoparticles polyvinyl alcohol polymer composite (CuNP-PVA) based saturable absorber (SA). The modulation depth and the saturation power intensity of the CuNP-PVA film are calculated as 18 % and 0.021 kW/cm2, respectively. A maximum repetition rate of 104.2 kHz, the shortest pulse width of 5.1 µs and pulse energy up to 20.4 nJ was observed at 1558 nm wavelength.
Recalibrating climate prospects
Authors: Lovins Amory B , Ürge-Vorsatz Diana , Mundaca Luis , Kammen Daniel M , Glassman Jacob W
Published: December 2019

IPCC’s 2018 Special Report is a stark and bracing reminder of climate threats. Yet literature, reportage, and public discourse reflect imbalanced risk and opportunity. Climate science often understates changes’ speed and nonlinearity, but Integrated Assessment Models (IAMs) and similar studies often understate realistic mitigation options. Since ∼2010, global mitigation of fossil CO2—including by often-uncounted modern renewable heat comparable to solar-plus-wind electricity—has accelerated to about the pace (if sustained) needed for a 2 °C trajectory. Mitigation has uncertainties, emergent properties, feasibility thresholds, and nonlinearities at least comparable to climate’s, creating opportunities for aggressive action. Renewable electricity’s swift uptake can now be echoed as proven integrative design can make end-use efficiency severalfold larger and cheaper, often with increasing returns (lower cost with rising quantity). Saved energy—the world’s largest decarbonizer and energy ‘source’ (bigger than oil)—can then potentiate renewables and cut supply investments, as a few recent efficiency-centric IAMs confirm. Optimizing choices, combinations, timing, and sequencing of technologies, urban form, behavioral shifts, etc could save still more energy, money, and time. Some rigorous engineering-based national studies outside standard climate literature even imply potential 1.5 °C global trajectories cheaper than business-as-usual. A complementary opportunity—rapidly and durably abating hydrocarbon industries’ deliberate upstream CH4 releases from flares and engineered vents, by any large operator’s profitably abating its own and others’ emissions—could stabilize (or more) the global methane cycle and buy time to abate more CO2. Together, these findings justify sober recalibration of the prospects for a fairer, healthier, cooler, and safer world. Supported by other disciplines, improved IAMs can illuminate this potential and support its refinement. Ambitious policies and aggressive marketplace and societal adoption of profitable new abatement opportunities need not wait for better models, but better models would help them to attract merited attention, scale faster, and turn numbing despair into collectively powerful applied hope.
Snowpack properties vary in response to burn severity gradients in montane forests
Authors: Maxwell Jordan , St Clair Samuel B
Published: December 2019

Wildfires are altering ecosystems globally as they change in frequency, size, and severity. As wildfires change vegetation structure, they also alter moisture inputs and energy fluxes which influence snowpack and hydrology. In unburned forests, snow has been shown to accumulate more in small clearings or in stands with low to moderate forest densities. Here we investigate whether peak snowpack varies with burn severity or percent overstory tree mortality post-fire in a mid-latitude, subalpine forest. We found that peak snowpack across the burn severity gradients increased 15% in snow-water equivalence (SWE) and 17% in depth for every 20% increase in overstory tree mortality due to burn severity. Snowpack quantity varied greatly between the two winter seasons sampled in this study with 114% more snow in 2016 versus 2015, yet the effect of burn severity on snowpack remained consistent. These data support previous studies showing increases in peak snow depth and SWE in burned forests but for the first time provides novel insights into how snow depth and SWE change as a function of burn severity. We conclude that changes not only in the frequency and size of wildfires, but also in the severity, can alter peak snow depth and SWE, with important potential implications for watershed hydrology.
Corrigendum: GAN-Based Augmentation for Improving CNN Performance of Classification of Defective Photovoltaic Module Cells in Electroluminescence Images (IOP Conf. Ser.: Earth Environ. Sci. 354 012106)
Authors: Luo Z , Cheng S Y , Zheng Q Y
Published: December 2019

The corresponding author acknowledges not correctly referencing the content taken fromhttps://github.com/zae-bayern/elpv-dataset. The author apologises for the error.

Corrigendum published: 29 November 2019
Preparation and characterization of chromium metal organic framework with trimesic or terephthalic acid in carbon dioxide adsorption
Authors: Chong K C , Foo P L , Lai S O , Thiam H S , Lee S S , Lau W J
Published: December 2019

Greenhouse gases (GHGs) have greatly changed the global climate in the recent year. Metal organic frameworks (MOFs) is one of the solutions which can be utilized as gas adsorbents to capture carbon dioxide (CO2), the main contributor of greenhouse effect. MOF possesses good CO2 adsorption ability attributed to its high surface area to volume ratio and pore size. Nevertheless, the success of the MOF is greatly depend on the fabrication parameter such as fabrication methods, type of metal oxide, type of organic linkers used and the molar ratio of the reactant. In this study, chromium (VI) oxide, trimesic acid and terephthalic acid were used to fabricate MOFs by solvothermal method to investigate the performance of CO2 adsorption. The characterization tests by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) shows that Cr-TMA-1:5 amongst the rest of the fabricated MOF possess the shape of small irregular diagonal with highest surface area to volume ratio which was ideal in CO2 adsorption. Furthers, the result CO2 adsorption test carried by thermogravimetric analyser (TGA) suggested the MOF Cr-TMA-1:5 possesses the highest the CO2 adsorption capacity recorded at 0.099 mmol/g. This had revealed that MOFs composed of chromium (VI) oxide and trimesic acid possess the potential to be applied in CO2 adsorption.
Theory and derivation of unsymmetrical rotor equation of the foil-air bearing rotor system and its validation with experiment data
Authors: Hassan M F
Published: December 2019

This manuscript presents the theory and derivation of rotor equation using rigid body modelling used to validate the modal transformation approach for solving foil-air bearing rotor system. Numerical coefficient of the rotor equation for both methods only different less than 3%. The reasonable correlation in term of orbit’s orientation with experimental data, has proved that the rotor was correctly modelled and adapted with simultaneous solution technique and modal model of foil structure.
Fundamental study on the optimal path of centrifugal pendulum vibration absorbers in automatic transmissions
Authors: Ryu T , Nakae T , Matsuzaki K , Ozaki J
Published: December 2019

In recent years, high-power and low-cylinder engines have seen increasingly widespread use. These engines produce a strong torsional vibration due to engine combustion. Furthermore, automatic transmissions necessitate the use of a lock-up clutch system that directly links the engine and gear train when the engine rotational speed is low. Using a torsional spring called a lock-up damper in the torque converter is not sufficient to absorb the torsional vibration. Therefore, the centrifugal pendulum vibration absorber (CPVA) has been developed to suppress the torsional vibration. The natural frequency of a CPVA is proportional to the engine rotational speed, and it is expected to suppress the torsional vibration over a wide range of speeds. However, the natural frequency of the CPVA varies because of the nonlinearity when the vibration amplitude of the CPVA is large. In this study, the optimal path of the CPVA to suppress the torsional vibration of the engine was investigated.
Effect of metal cutting fluid (MCF) conditions on tool wear and thrust force in drilling Ti-6Al-4V using coated carbide tools
Authors: Rashid R A , Murad M N , Hamidon R , Shariffuddin S
Published: December 2019

Titanium alloy (Ti-6Al-4V) is well known as difficult to cut material due to their low machinability rating. Machining Ti-6Al-4V generate high cutting temperature close to the cutting edge of the tool. The high cutting temperature, mostly during the deformation process and friction at the tool–chip and tool–workpiece interfaces. This circumstances will lead to the rapid tool wear. This study focuses on the growth of tool wear and development of the thrust force. Drilling tests were conducted using coated (TiAlN) carbide tool with diameter of 6 mm under two different condition of metal cutting fluid (MCF). The MCF used were minimum quantity lubrication (MQL) and minimum quantity cooling lubrication (MQCL). The outcomes of this study indicates MQL performed better coolant-lubricant effect during drilling Ti-6Al-4V as the results of thrust force development are consistent with the trends of tool wear growth.