Extrinsic Factors Research Articles

Evidence-based practice in canine artificial insemination.

A number of methods are currently used to predict the optimal date of insemination of the breeding bitch, particularly with the use of frozen-thawed canine semen which has a far shorter lifespan than fresh semen. Aside from confirming cytological oestrus, vaginal cytology is of no assistance in predicting the most fertile day(s) in a bitch; however, a neglected avenue of research suggests that vaginal cytology may be of great importance in confirming the days of optimal fertility retrospectively. Similarly, vaginoscopy provides clues as to the stage of a bitch's cycle but is inadequate as a sole determinant of her most fertile days. Nevertheless, vaginoscopy is useful to identify very late oestrus and the onset of dioestrus, as well as Stage I of labour (cervical dilatation). Due to variations in the rate at which circulating progesterone concentrations rise in individual bitches, the reliability of circulating progesterone concentrations for determining the optimal day(s) of insemination with frozen-thawed semen decreases as values rise. Moreover, progesterone assay results can vary widely due to extrinsic factors such as the time of blood sampling, sample storage conditions and the assay employed. Finally, this review investigates evidence surrounding various insemination routes and suggests that well-performed vaginal insemination, even with frozen-thawed semen, may be an acceptable approach for cases where transcervical insemination is impractical.

A Mesenchymal stem cell Aging Framework, from Mechanisms to Strategies.

Mesenchymal stem cells (MSCs) are extensively researched for therapeutic applications in tissue engineering and show significant potential for clinical use. Intrinsic or extrinsic factors causing senescence may lead to reduced proliferation, aberrant differentiation, weakened immunoregulation, and increased inflammation, ultimately limiting the potential of MSCs. It is crucial to comprehend the molecular pathways and internal processes responsible for the decline in MSC function due to senescence in order to devise innovative approaches for rejuvenating senescent MSCs and enhancing MSC treatment. We investigate the main molecular processes involved in senescence, aiming to provide a thorough understanding of senescence-related issues in MSCs. Additionally, we analyze the most recent advancements in cutting-edge approaches to combat MSC senescence based on current research. We are curious whether the aging process of stem cells results in a permanent "memory" and if cellular reprogramming may potentially revert the aging epigenome to a more youthful state.

Understanding Mechanisms and Key Factors Influencing Melanogenesis for the Management of Melasma: An Updated Review.

Melanocytes are highly specialized dendritic cells that deliver melanin to keratinocytes in melanosomes, which are subcellular organelles where melanin is produced and stored. Mammal's skin, hair, and eyes all contain the complex pigment melanin, which gives them color and ultraviolet protection. Melanins have the potential to be free radical sinks and are strong cation chelators. Amino acid tyrosine and its metabolite, dopa, are the precursors to complex metabolic processes that end with melanin production. Melanocytes generate different types and amounts of melanin, which is defined genetically and is impacted by several extrinsic and intrinsic factors such as hormone fluctuations, inflammation, age, and ultraviolet radiation exposure, leading to the stimulation of numerous melanogenesis pathways. Melasma, a common skin pigmentation condition, is associated with the overproduction of melanin and is characterized by brown to gray-brown and black spots that mostly affect the face. The present review addresses the regulatory mechanisms and signaling pathways involved in skin pigmentation with an emphasis on the altered melanogenesis that causes melasma and hyperpigmentation. The current study also illustrates the available treatment options with cellular and molecular mechanisms for the management of melasma. Understanding the mechanism of the pigmentation process may help researchers develop new therapeutic strategies and novel drugs for the management of melasma.

Magneto-transport in the monolayer MoS2 material system for high-performance field-effect transistor applications

Electronic transport in monolayer MoS2 is significantly constrained by several extrinsic factors despite showing good prospects as a transistor channel material. Our paper aims to unveil the underlying mechanisms of the electrical and magneto-transport in monolayer MoS2. In order to quantitatively interpret the magneto-transport behavior of monolayer MoS2 on different substrate materials, identify the underlying bottlenecks, and provide guidelines for subsequent improvements, we present a deep analysis of the magneto-transport properties in the diffusive limit. Our calculations are performed on suspended monolayer MoS2 and MoS2 on different substrate materials taking into account remote impurity and the intrinsic and extrinsic phonon scattering mechanisms. We calculate the crucial transport parameters such as the Hall mobility, the conductivity tensor elements, the Hall factor, and the magnetoresistance over a wide range of temperatures, carrier concentrations, and magnetic fields. The Hall factor being a key quantity for calculating the carrier concentration and drift mobility, we show that for suspended monolayer MoS2 at room temperature, the Hall factor value is around 1.43 for magnetic fields ranging from 0.001 to 1 Tesla, which deviates significantly from the usual value of unity. In contrast, the Hall factor for various substrates approaches the ideal value of unity and remains stable in response to the magnetic field and temperature. We also show that the MoS2 over an Al2O3 substrate is a good choice for the Hall effect detector. Moreover, the magnetoresistance increases with an increase in magnetic field strength for smaller magnetic fields before reaching saturation at higher magnetic fields. The presented theoretical model quantitatively captures the scaling of mobility and various magnetoresistance coefficients with temperature, carrier densities, and magnetic fields.

Driver Mutations in Pancreatic Cancer and Opportunities for Targeted Therapy

Pancreatic cancer is the sixth leading cause of cancer-related mortality globally. As the most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) represents up to 95% of all pancreatic cancer cases, accounting for more than 300,000 deaths annually. Due to the lack of early diagnoses and the high refractory response to the currently available treatments, PDAC has a very poor prognosis, with a 5-year overall survival rate of less than 10%. Targeted therapy and immunotherapy are highly effective and have been used for the treatment of many types of cancer; however, they offer limited benefits in pancreatic cancer patients due to tumor-intrinsic and extrinsic factors that culminate in drug resistance. The identification of key factors responsible for PDAC growth and resistance to different treatments is highly valuable in developing new effective therapeutic strategies. In this review, we discuss some molecules which promote PDAC initiation and progression, and their potential as targets for PDAC treatment. We also evaluate the challenges associated with patient outcomes in clinical trials and implications for future research.

Stem cell‐derived cardiomyocyte heterogeneity confounds electrophysiological insights

AbstractHuman induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs) offer potential as an in vitro model for studying drug cardiotoxicity and patient‐specific cardiovascular disease. The inherent electrophysiological heterogeneity of these cells limits the depth of insights that can be drawn from well‐designed experiments. In this review, we provide our perspective on some sources and the consequences of iPSC‐CM heterogeneity. We demonstrate the extent of heterogeneity in the literature and explain how such heterogeneity is exacerbated by patch‐clamp experimental artifacts in the manual and automated set‐up. Finally, we discuss how this heterogeneity, caused by both intrinsic and extrinsic factors, limits our ability to build digital twins of patient‐derived cardiomyocytes. image

Intrinsic and extrinsic contributors to subregional thalamic volume loss in multiple sclerosis.

To evaluate the intrinsic and extrinsic microstructural factors contributing to atrophy within individual thalamic subregions in multiple sclerosis using in vivo high-gradient diffusion MRI. In this cross-sectional study, 41 people with multiple sclerosis and 34 age and sex-matched healthy controls underwent 3T MRI with up to 300 mT/m gradients using a multi-shell diffusion protocol consisting of eight b-values and diffusion time of 19 ms. Each thalamus was parcellated into 25 subregions for volume determination and diffusion metric estimation. The soma and neurite density imaging model was applied to obtain estimates of intra-neurite, intra-soma, and extra-cellular signal fractions for each subregion and within structurally connected white matter trajectories and cortex. Multiple sclerosis-related volume loss was more pronounced in posterior/medial subregions than anterior/ventral subregions. Intra-soma signal fraction was lower in multiple sclerosis, reflecting reduced cell body density, while the extra-cellular signal fraction was higher, reflecting greater extra-cellular space, both of which were observed more in posterior/medial subregions than anterior/ventral subregions. Lower intra-neurite signal fraction in connected normal-appearing white matter and lower intra-soma signal fraction of structurally connected cortex were associated with reduced subregional thalamic volumes. Intrinsic and extrinsic microstructural measures independently related to subregional volume with heterogeneity across atrophy-prone thalamic nuclei. Extrinsic microstructural alterations predicted left anteroventral, intrinsic microstructural alterations predicted bilateral medial pulvinar, and both intrinsic and extrinsic factors predicted lateral geniculate and medial mediodorsal volumes. Our results might be reflective of the involvement of anterograde and retrograde degeneration from white matter demyelination and cerebrospinal fluid-mediated damage in subregional thalamic volume loss.

Analyzing the Effects of Age, Time of Day, and Experiment on the Basal Locomotor Activity and Light-Off Visual Motor Response Assays in Zebrafish Larvae

The recent availability of commercial platforms for behavioral analyses in zebrafish larvae based on video-tracking technologies has exponentially increased the number of studies analyzing different behaviors in this model organism to assess neurotoxicity. Among the most commonly used assays in zebrafish larvae are basal locomotor activity (BLA) and visual motor responses (VMRs). However, the effect of different intrinsic and extrinsic factors that can significantly alter the outcome of these assays is still not well understood. In this work, we have analyzed the influence of age (5–8 days post-fertilization), time of day (8:00, 10:00, 12:00, 14:00; 16:00, 18:00, and 20:00 h), and experiment (three experiments performed at different days) on BLA and VMR results (4004 analyses for each behavior) in 143 larvae. The results from both behaviors were adjusted to a random-effects linear regression model using generalized least squares (GLSs), including in the model the effect of the three variables, the second-way interactions between them, and the three-way interaction. The results presented in this manuscript show a specific effect of all three intrinsic factors and their interactions on both behaviors, supporting the view that the most stable time period for performing these behavioral assays is from 10:00 am to 04:00 pm, with some differences depending on the age of the larva and the behavioral test.

Nanostructured High Entropy Alloys as Structural and Functional Materials.

Since their introduction in 2004, high entropy alloys (HEAs) have attracted significant attention due to their exceptional mechanical and functional properties. Advances in our understanding of atomic-scale ordering and phase formation in HEAs have facilitated the development of fabrication techniques for synthesizing nanostructured HEAs. These materials hold immense potential for applications in various fields including automobile industries, aerospace engineering, microelectronics, and clean energy, where they serve as either structural or functional materials. In this comprehensive Review, we conduct an in-depth analysis of the mechanical and functional properties of nanostructured HEAs, with a particular emphasis on the roles of different nanostructures in modulating these properties. To begin, we explore the intrinsic and extrinsic factors that influence the formation and stability of nanostructures in HEAs. Subsequently, we delve into an examination of the mechanical and electrocatalytic properties exhibited by bulk or three-dimensional (3D) nanostructured HEAs, as well as nanosized HEAs in the form of zero-dimensional (0D) nanoparticles, one-dimensional (1D) nanowires, or two-dimensional (2D) nanosheets. Finally, we present an outlook on the current research landscape, highlighting the challenges and opportunities associated with nanostructure design and the understanding of structure-property relationships in nanostructured HEAs.

21ST CENTURY PEDAGOGICAL SKILLS AND ACADEMIC MOTIVATION OF TEACHERS IN ENGLISH SUBJECT

In the rapidly evolving landscape of education, the traditional teaching paradigms are being reshaped by the demands of the 21st century. This study conducted in Hagonoy 2 District, Division of Davao del Sur, aimed to explore the relationship between 21st-century pedagogical skills of teachers and learners academic motivation in English subjects. A quantitative research approach employing descriptive-correlational methods was utilized. Data were gathered from 200 English teachers through probability sampling. Statistical tools including mean, Pearson correlation, and regression analysis were employed for data analysis. Findings revealed that the extent of 21st-century pedagogical skills among teachers was very extensive, encompassing critical thinking, collaboration, communication, and creativity and innovation. Similarly, learners academic motivation was found to be extensive, with both intrinsic and extrinsic factors playing significant roles. Importantly, a significant relationship was identified between teachers pedagogical skills and learners academic motivation. The study concluded that effective pedagogy, which goes beyond content delivery, involves understanding students needs and creating engaging learning environments. Recommendations included crafting effective policies to enhance pedagogical skills, providing professional development opportunities for teachers, and fostering continuous monitoring of learners academic motivation. Future research avenues were also suggested to further explore the dynamics between pedagogical skills and academic motivation. KEYWORDS: 21st century pedagogical skills, academic motivation, Hagonoy 2 District, Division of Davao del Sur, Philippines

Believing in the power of belief: a study on the formation mechanism of innovative behavior from the perspectives of intrinsic and extrinsic spiritual inspiration

PurposeThis study reveals the trigger of innovative behavior from the perspective of intrinsic and extrinsic spiritual inspiration and provides a new research idea for the formation mechanism of innovative behavior. The purpose of this study is to provide certain guidance and implications for enterprises to cultivate and enhance employees’ innovative behavior.Design/methodology/approachWe conducted three studies, collected multi-source data (N = 1,175) from different countries longitudinally, as well as used hierarchical regression analysis and fuzzy-set quantitative comparative analysis to verify the theoretical model.FindingsAccording to the findings, both spiritual leadership and career calling have a positive impact on employees’ innovative behavior through the mediating effect of autonomous motivation and the moderating effect of person-vocation fit.Originality/valueInnovative behavior is the positive professional pursuit of employees, which is difficult to form without the motivation of spiritual factors. Spirituality is a complex concept that contains intrinsic and extrinsic spiritual factors, both of which could stimulate employees’ innovative behavior. Although many discussions have been held on this topic in recent years, little attention has been paid simultaneously to the motivating effects of the two perspectives. Drawn from self-determination theory, this study explores the mechanisms of two spiritual motivation paths (i.e. the intrinsic and extrinsic spiritual motivation paths) in the improvement of employees’ innovative behavior.

Enhancing Employee Well-Being and Productivity in Evolving Work Environments

The evolving nature of work environments has led to an increasing emphasis on holistic employee development, recognizing the importance of emotional well-being, spiritual values, restoration, and motivation in the workplace. Research shows that emotional intelligence, workplace spirituality, emotional regulation, and emotional interdependence influence employee well-being and productivity. Spiritual values provide meaning, purpose, interconnectedness, and community, supporting performance. Restoration through natural environments and restorative practices enhances well-being and motivation. Employee engagement involves intrinsic factors like meaningful work, extrinsic factors like rewards, organizational support, work-life balance, training and development, recognition, job design, and organizational culture. Strategies for diverse spiritual beliefs include inclusive policies, nourishing spirit at work, managing beliefs, open expression, humanistic environment, accommodating demands, and studying experiences. Promoting work-life balance involves flexible policies, wellness support, arrangements, connections, formal and informal support, empowerment, family-friendly policies, and assessments. Rest, rejuvenation, and leisure contribute to health, reduced stress, productivity, and motivation. Motivational factors for engagement include intrinsic motivation, extrinsic motivation, organizational support, work-life balance, training and development, recognition, job design, and culture.    Received: 12 February 2024 / Accepted: 19 April 2024 / Published: 5 May 2024

Macroevolution of the plant-hummingbird pollination system.

Plant-hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant-hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre-dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build-up of both diversities coinciding temporally, and hence suggesting co-diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species-level interaction data in macroevolutionary studies.

Do wolves control their own numbers? Understanding and updating the long debate

The population dynamics of animals involve a complex interplay between intrinsic and extrinsic factors. Intrinsic regulation, characterized as population self‐regulation, encompasses mechanisms that moderate growth rates before reaching maximum food‐dependent densities. Conversely, extrinsically regulated populations are constrained by environmental variables such as food availability, predation, and disease. What regulates wolf populations has been debated for decades, with most publications concluding that wolves are extrinsically regulated, despite evidence of intrinsic mechanisms. This paper summarizes one perspective from a debate at the 'Wolves Across Borders' conference in Stockholm, Sweden in May 2023. Since this paper is a summary of a public debate, the paper is neither a review nor research paper, rather a research history and a recommendation on how the long‐term disagreement might be resolved. Wolf population regulation is likely an interplay between both intrinsic and extrinsic factors which is best studied longitudinally by monitoring one population through time.

Device engineering of Sb2X3 antimony chalcogenide for loss analysis and strategies for maximizing photovoltaic efficiency

Abstract Antimony chalcogenide (Sb2X3; X=S, Se) is reportedly stable in ambient open-air, abundant, and composition-dependent absorption tunability. We simulated the Sb2X3 device utilizing the reported optical and electrical properties to analyze its reported efficiency critically and the extent of achievable performance. Initially, we benchmarked the simulated device with the experimental reported device. The temperature-VOC, illumination-VOC characterization of the benchmarked device revealed contact issue responsible for the VOC deficit. The suboptimal device configuration is major performance-limiting factor. Contact optimization improved efficiency to 15% and 20% in Sb2S3 and Sb2Se3, respectively. The optimization of trap-assisted Shockley Read Hall (SRH) recombination in bulk and interface has improved efficiency to 19% and 26% in Sb2S3 and Sb2Se3, respectively. When extrinsic factors are optimised, such as resistance losses (series resistance as high as 2 Ωcm2 and shunt resistance as low as 1000 Ωcm2), efficiency increased to 27.5%. Finally, with ideal intrinsic recombination parameters (radiative and Auger recombination), efficiency improved to theoretical limits (corresponding to their band gap). The study highlights the possibility of immediate gain upon contact passivation in Sb2S3 and Sb2Se3.

Methods and techniques of forming the perceptions and motivation of English teachers

The article explores the dynamic methodologies and strategies used to shape perceptions and enhance motivation among English teachers. Recognizing the crucial role educators play in language acquisition and proficiency, it provides a comprehensive review of innovative methods designed to invigorate and empower these teachers. The study incorporates interdisciplinary perspectives from psychology, pedagogy, and cognitive sciences to examine approaches like positive reinforcement, professional development programs, peer collaboration, and technology integration. It also assesses the impact of intrinsic and extrinsic motivational factors on teacher efficacy and classroom dynamics. By integrating empirical research and best practices, the article offers valuable insights for educational stakeholders aiming to create a vibrant and engaging learning environment for teachers and students alike.

Unveiling machine learning's impact on in vitro callogenesis optimization in Crocus sativus L

Saffron is a spice derived from its flower (Crocus sativus L.) and it is grown for its medicinal and culinary uses worldwide. Callus is an intermediate stage between explant and in vitro organogenesis. The fate of embryogenesis and organogenesis depends on the quality of the callus. Callogenesis is a complex biological process and is affected by various intrinsic and extrinsic factors. Machine learning (ML), can effectively cope with the time and cost constraints of experiments. In this study, we emphasized the effects of sucrose and phytohormones (auxin, and abscisic acid) on callogenesis with the aid of a machine-learning algorithm. Among the different tested hormone combinations, maximum callus proliferation was observed in the MS media plate containing 3 % sucrose, supplemented with 100 µM ABA, 2 and 4 mg/L NAA, and 2,4-D. A total of eight different ML tools were used to predict the efficacy of inputs on callogenesis. Out of all applied algorithms, Xtreme Gradient Boosting (XGB) and Gradient Boosted Regression (GBR) provide better prediction performance than other models on callus induction and proliferation. SHAP analysis reveals the significance of sucrose, plant growth regulators (NAA, 2,4-D, and ABA), and time on callogenesis. Therefore, machine learning programs can effectively save cost and time by guiding experiments and facilitating optimization.

Concentration-QTc modeling of sitravatinib in patients with advanced solid malignancies.

Sitravatinib (MGCD516) is an orally available, small molecule, tyrosine kinase inhibitor that has been evaluated in patients with advanced solid tumors. Concentration-corrected QT interval (QTc; C-QTc) modeling was undertaken, using 767 matched concentration-ECG observations from 187 patients across two clinical studies in patients with advanced solid malignancies, across a dose range of 10-200 mg, via a linear mixed-effects (LME) model. The effect on heart rate (HR)-corrected QT interval via Fridericia's correction method (QTcF) at the steady-state maximum concentration (Cmax,ss) for the sitravatinib proposed therapeutic dosing regimen (100 mg malate once daily [q.d.]) without and with relevant intrinsic and extrinsic factors were predicted. No significant changes in HR from baseline were observed. Hysteresis between sitravatinib plasma concentration and change in QTcF from baseline (ΔQTcF) was not observed. There was no significant relationship between sitravatinib plasma concentration and ΔQTcF. The final C-QTc model predicted a mean (90% confidence interval [CI]) ΔQTcF of 3.92 (1.95-5.89) ms and 2.94 (0.23-6.10) ms at the proposed therapeutic dosing regimen in patients with normal organ function (best case scenario) and patients with hepatic impairment (worst-case scenario), respectively. The upper bounds of the 90% CIs were below the regulatory threshold of concern of 10 ms. The results of the described C-QTc analysis, along with corroborating results from nonclinical safety pharmacology studies, indicate that sitravatinib has a low risk of QTc interval prolongation at the proposed therapeutic dose of 100 mg malate q.d.

Techno-functional and physicochemical properties of corn flours as potential food ingredients

Background and Objectivescorn plays a crucial role in food security and nutrition. This study aimed to assess the impact of three corn cultivars (Advanta, Leptra, and Porva) and varying particle sizes of flours on estimated glycemic index (eGI), techno-functional properties, and rheological behaviors, crucial in defining their technological properties. FindingsWAI and WSI presented differences among particle sizes for Advanta and Leptra corn flours, whereas Porva flour displayed consistent results regardless of particle sizes. Notably, while Advanta and Leptra did not showed differences in eGI and its fractions, Advanta (174.4 µm) demonstrated the lowest eGI at 32.21, alongside higher water-holding capacity (WHC) compared to wheat flours. Further findings included an initial Emulsification Activity Index (EAI) of 40.55 m2/g and a minimum gelation concentration (LGC) of 12%. Additionally, rheological characterization indicated a non-Newtonian and pseudoplastic behavior. Conclusionsthis study presented a corn flour with high resistant starch content and low glycemic index with functional properties that could be applied to manufacture healthy food requiring high water solubility, greater emulsification capacity, and water retention capacity greater than conventional flours. Significance and Noveltythe study on intrinsic and extrinsic factors that can modulate the glycemic index of corn becomes crucial. This exploration holds the potential to design healthy commercially viable products.

Wicked problem of improving fishery livelihoods through capacity building

Development programs can train fishers in value-adding but factors influencing who is likely to benefit are not well understood. Small-scale fishers worldwide often fall short increasing the value of their catch and wellbeing benefits from their harvests. Here, we sought to improve technical capacity of sea cucumber fishers in postharvest processing and examine intrinsic and extrinsic factors that shape long-term livelihood impacts. Manuals, videos and village-based workshops were used to train hundreds of fishers in 29 villages across seven island regions in Fiji. Our linear mixed models found that trained fishers spent more time processing their catch and were more likely to report increased sale prices. However, the fishery was in decline and so fishers’ weekly incomes did not improve overall. The capacity building led to gender-transformative outcomes by motivating women to increase catch rates and it improved their weekly fishery income. Perceived changes in trading prices and economic dependence on the fishery varied regionally, implying inconsistent trader behaviour. Our study reveals that improving fishery livelihoods can be a “wicked problem” involving a complexity of external factors that hinder livelihood impacts. Capacity-building of fishers was insufficient on its own to markedly improve wellbeing. Income also depended on the fishery stocks, equitable behaviour of traders and access of fishers to raw materials for postharvest processing. Development programs should consider a holistic approach through partnerships with institutions to improve the management of natural resources, value chains and technical capacity of fishers.