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Find video protocols related to scientific articles indexed in Pubmed.
Juvenile hormone-receptor complex acts on mcm4 and mcm7 to promote polyploidy and vitellogenesis in the migratory locust.
PLoS Genet.
PUBLISHED: 10-01-2014
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Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation.
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Ultra-bright alkylated graphene quantum dots.
Nanoscale
PUBLISHED: 09-06-2014
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Highly efficient and stable photoluminescence (PL) are urgently desired for graphene quantum dots (GQDs) to facilitate their prospective applications as optical materials. Here, we report the facile and straightforward synthesis of alkylated graphene quantum dots (AGQDs) via the solvothermal reaction of propagatively alkylated graphene sheets (PAGenes). In contrast to most GQDs reported so far, the synthesized AGQDs process pH-independent and ultra-bright PL with a relative quantum yield of up to 65%. Structural and chemical composition characterization demonstrated that the synthesized AGQDs are nearly oxygen-defect-free with alkyl groups decorated on edges and basal plane, which may contribute to their greatly improved pH tolerance and high quantum efficiency. The photocatalytic performance of AGQDs-P25 nanocomposites was evaluated by the degradation of Rhodamine B under visible light. The photocatalytic rate is ca. 5.9 times higher than that of pure P25, indicating that AGQDs could harness the visible spectrum of sunlight for energy conversion or environmental therapy.
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Krüppel-homolog 1 mediates juvenile hormone action to promote vitellogenesis and oocyte maturation in the migratory locust.
Insect Biochem. Mol. Biol.
PUBLISHED: 03-13-2014
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Juvenile hormone (JH) prevents insect larval metamorphosis and stimulates processes for adult reproduction. Krüppel-homolog 1 (Kr-h1), a zinc finger transcription factor, is shown to mediate the anti-metamorphic effect of JH in both holometabolous and hemimetabolous insects. However, the role of Kr-h1 in JH-mediated reproduction has not been determined. Using the migratory locust, Locusta migratoria, we showed here that Kr-h1 was expressed in response to JH in female adults, and Kr-h1 transcription was directly regulated by the JH-receptor complex comprised of Methoprene-tolerant (Met) and steroid receptor co-activator. We demonstrated that Kr-h1 RNAi phenocopied Met RNAi and JH-deprived condition during post-eclosion development and vitellogenesis of female locusts. Knockdown of Kr-h1 resulted in substantial reduction of Vg expression in the fat body and lipid accumulation in the primary oocytes, accompanied by blocked follicular epithelium development, oocyte maturation and ovarian growth. Our data therefore reveal a crucial role of Kr-h1 in insect vitellogenesis and egg production. This study suggests that JH-Met-Kr-h1 signaling pathway is also functional in insect reproduction.
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Seroprevalence of Toxoplasma gondii infection in pigs in Jiangxi Province, Southeastern China.
Foodborne Pathog. Dis.
PUBLISHED: 02-19-2014
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Toxoplasma gondii is the causative agent of toxoplasmosis in humans and a wide range of animal species. In the current study, a serological investigation using an indirect hemagglutination (IHA) test was carried out to determine the seroprevalence of T. gondii infection in pigs in Jiangxi Province, southeastern China. A total of 1232 serum samples were collected from pigs in 10 administrative districts in Jiangxi, and specific antibodies were detected in 282 pigs (22.9%) with the titers ?1:64. Positive pigs were found in each administrative district, with prevalence ranging from 5.0% to 46.2%. Age and season were found to be associated with T. gondii infection. Lactating sows (odds ratio [OR]=15.4, 95% confidence interval [CI]=6.8-35.2, p<0.01), pregnant sows (OR=11.5, 95% CI=5.3-24.8, p<0.01), nonpregnant sows (OR=13.7, 95% CI=6.4-29.3, p<0.01), breeding boars (OR=9, 95% CI=3.8-21.4, p<0.01), and fattening pigs (OR=4.9, 95% CI=2.1-11.7, p<0.01) all had a greater risk of acquiring infection compared to the weanling pigs. There is a higher risk of infection in the spring (OR=1.7, 95% CI=1.1-2.6, p=0.01) and the summer (OR=2.1, 95% CI=1.3-3.2, p<0.01) than in the winter. This is the first documentation of T. gondii seroprevalence in pigs in Jiangxi Province, which enriches the epidemiological data of T. gondii infection in pigs in China. The results of this study indicate that pigs in Jiangxi Province are frequently exposed to T. gondii, posing a direct threat to the pig industry as well as to public health. Integrated strategies are needed to strengthen future prevention and control of T. gondii infection in pigs in this region.
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Genetic characterization of Toxoplasma gondii from pigs from different localities in China by PCR-RFLP.
Parasit Vectors
PUBLISHED: 06-14-2013
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Toxoplasma gondii is a widely prevalent protozoan parasite that causes serious toxoplasmosis in humans and animals. The present study aimed to determine the genetic diversity of T. gondii isolates from pigs in Jiangxi, Sichuan, Guangdong Provinces and Chongqing Municipality in China using multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology.
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Calcium sensing receptor absence delays postnatal brain development via direct and indirect mechanisms.
Mol. Neurobiol.
PUBLISHED: 01-16-2013
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Calcium sensing receptor (CaSR) is implicated in the establishment of neural connections and myelin formation. However, its contribution to brain development remains unclear. We addressed this issue by analyzing brain phenotype in postnatal CaSR null mice, a model of human neonatal severe hyperparathyroidism. One- and 2-week-old CaSR null mice exhibited decreased brain weight and size with a developmental delay in expression of proliferating cell nuclear antigen. Neuronal and glial differentiation markers, neuronal specific nuclear protein, glial fibrillary acidic protein, and myelin basic protein, were also decreased compared with age-matched wild-type littermates. Moreover, deletion of the parathyroid hormone gene that corrects hyperparathyroidism, hypercalcemia, hypophosphatemia, and whole-body growth retardation normalized brain cell proliferation, but not differentiation, in CaSR null mice. Cultured neural stem cells (NSCs) derived from the subventricular zones of CaSR null neonatal mice exhibited normal proliferation capacity but decreased differentiation capacity, compared with wild-type controls. These results demonstrate that direct effects of CaSR absence impair NSC differentiation, while secondary effects of parathyroid hormone-related endocrine abnormalities impair NSC proliferation, both of which contribute to delayed brain development in CaSR null newborn mice.
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[The application of improved Glasgow coma scale score of 15 as switching point for invasive noninvasive mechanical ventilation in treatment of severe respiratory failure in chronic obstructive pulmonary disease].
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 04-09-2011
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To estimate the feasibility and the efficacy of early extubation and the sequential non invasive mechanical ventilation (MV) in severe respiratory failure of chronic obstructive pulmonary disease (COPD) with the improved Glasgow coma scale (GCS) score of 15 as the switching point.
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TDP-43 in aging and Alzheimers disease - a review.
Int J Clin Exp Pathol
PUBLISHED: 01-28-2011
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Transactive response DNA-binding protein of 43 kDa (TDP-43), an RNA and DNA binding protein involved in transcriptional repression, RNA splicing and RNA metabolism during the stress response, is the major component of neuronal inclusions in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin inclusions, now referred to as FTLD-TDP. While initially thought to be relatively specific to ALS and FTLD-TDP, TDP-43 pathology has now been detected in a number of other neurodegenerative diseases, many associated with tau pathology, including Guam Parkinson dementia complex and Alzheimers disease (AD). TDP-43 pathology is detected in 25% to 50% of AD cases, especially those with more severe clinical phenotype and greater Alzheimer type pathology, as well as AD cases with hippocampal sclerosis (HS). HS is characterized by selective neuronal loss affecting CA1 sector of the hippocampus, and most cases of HS, with or without AD, have TDP-43 pathology. Whether TDP-43 pathology is merely an incidental finding in AD or actually contributing to the more severe clinical phenotype remains unresolved. Presence of TDP-43 in normal elderly, who are at increased risk for AD, would strengthen the argument that it is not merely a secondary or incidental finding in end stage AD. Limited studies suggest that TDP-43 pathology is infrequent in neurologically normal elderly (3% or less). We provide an overview of what is known about TDP-43 in AD, normal aging and in other disorders and suggest that TDP-43 proteinopathies be considered in two classes - primary and secondary.
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[The effect of 1,25(OH)D3 deficiency in the secondary dentin formation and mineralization and caries of the mice].
Hua Xi Kou Qiang Yi Xue Za Zhi
PUBLISHED: 12-10-2010
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To determine the role of 1,25(OH)2D3 on the secondary dentin formation and mineralization of the mice.
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Expression and functional profiling of neprilysin, insulin-degrading enzyme, and endothelin-converting enzyme in prospectively studied elderly and Alzheimers brain.
J. Neurochem.
PUBLISHED: 07-30-2010
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The brain steady state level of ?-amyloid (A?) is determined by the balance between its production and removal, the latter through egress across blood and CSF barriers as well as A? degradation. The major A?-degrading enzymes are neprilysin (NEP), insulin-degrading enzyme (IDE), and endothelin-converting enzyme (ECE-1). Although evidence suggests that NEP is down-regulated in Alzheimers disease (AD), the role of IDE and ECE in the A? accumulation in aging and dementia remains less certain. In this study, we examined mRNA and protein expression, as well as biological activity of NEP, IDE, and ECE-1 in human frontal cortex by real-time RT-PCR for mRNA, immunoblotting for protein, and highly sensitive and specific fluorescence assays for activity. The relationships between A?-degrading enzymes and pathologic measures and clinical features were also assessed. The results showed that NEP mRNA, protein level, and activity were decreased in AD compared with normal controls with no cognitive impairment (NCI). In contrast, IDE activity was unchanged, but there was higher expression of IDE mRNA, indicating a possible compensatory reaction because of deficits in activity. ECE-1 expression in AD brain showed no significant difference compared with age-matched controls. Correlation analyses suggested that NEP expression was correlated with A? accumulation and clinical diagnosis, being lower in AD than in no cognitive impairment. In contrast, neither IDE nor ECE-1 correlated with A? or clinical diagnosis. These findings provide additional support for NEP as the major protease involved in A? degradation and suggest its possible therapeutic targeting in AD.
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Effects of HNE-modification induced by Abeta on neprilysin expression and activity in SH-SY5Y cells.
J. Neurochem.
PUBLISHED: 02-07-2009
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The cerebral accumulation of beta-amyloid (Abeta) is a consistent feature of and likely contributor to the development of Alzheimers disease. In addition to dysregulated production, increasing experimental evidence suggests reduced catabolism also plays an important role in Abeta accumulation. We have previously shown that neprilysin (NEP), the major protease which cleaves Abetain vivo, is modified by 4-hydroxy-nonenal (HNE) adducts in the brain of Alzheimers disease patients. To determine if these changes affected Abeta, SH-SY5Y cells were treated with HNE or Abeta, and then NEP mRNA, protein levels, HNE adducted NEP, NEP activity and secreted Abeta levels were determined. Intracellular NEP developed HNE adducts after 24 h of HNE treatment as determined by immunoprecipitation, immunoblotting, and double immunofluorescence staining. HNE-modified NEP showed decreased catalytic activity, which was associated with elevations in Abeta1-40 in SH-SY5Y and H4 APP695wt cells. Incubation of cells with Abeta1-42 also induced HNE adduction of NEP. In an apparent compensatory response, Abeta-treated cells showed increased NEP mRNA and protein expression. Despite elevations in NEP protein, the activity was significantly lower compared with the NEP protein level. This study demonstrates that NEP can be inactivated by HNE-adduction, which is associated with, at least partly, reduced Abeta cleavage and enhanced Abeta accumulation.
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Lentivirus-mediated RNAi knockdown of insulin-like growth factor-1 receptor inhibits growth, reduces invasion, and enhances radiosensitivity in human osteosarcoma cells.
Mol. Cell. Biochem.
PUBLISHED: 02-05-2009
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The type 1 insulin-like growth factor receptor (IGF-1R) is essential for tumorigenicity, tumor proliferation, and protection from apoptosis. IGF-1R overexpression has been found in many human cancers including osteosarcoma. To explore its possibility as a therapeutic target for the treatment of osteosarcoma, lentivirus-mediated siRNA was employed to downregulate endogenous IGF-1R expression to study the function of IGF-1R in tumorigenesis and radioresistance of osteosarcoma cells. The IGF-1R expression was persistently and markedly reduced by lentivirus-mediated RNAi. Downregulation of IGF-1R expression in osteosarcoma cells significantly suppressed their growth rates in vitro and reduced the potential of tumorigenicity in vivo. Moreover, the specific downregulation arrested cells in G(0)/G(1) phase of cell cycle and also induced apoptosis which correlated with the activation of Caspase-3. Furthermore, we also observed that suppression of IGF-1R could reduce the invasiveness of osteosarcoma cells and enhance their radiosensitivity. Our study suggested that lentivirus-mediated RNAi silencing targeting IGF-1R could induce potent antitumor activity and radiosensitizing activity in human osteosarcomas.
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[Calling and mating behaviors of bamboo shoot borer Kumasia kumaso].
Ying Yong Sheng Tai Xue Bao
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The calling and mating behaviors of Kumasia kumaso were studied in laboratory at (25 1) degrees C and (60 +/- 10) % RH under a cycle 14 L:10 D photo period, and the EAG response of male K. kumaso to female K. kumaso sex gland extracts was also tested. The calling and mating behaviors of K. kumaso could only be observed in scotophase. The females began calling at the first scotophase following emergence, and the peak of calling occurred during the second scotophase and decreased thereafter. The calling of the females commenced 0-4 h after dark, reached the maximum between the 5th and the 7th hour of the scotophase, and terminated during the last 1-2.5 h of the scotophase. Moth age had significant effects on the calling patterns. With increasing moth age, the onset time of calling advanced gradually, and the mean number of calling bouts as well as the calling length per bout had a gradual increase from calling day 1 to day 4 but decreased on day 5. The peak time and terminated time of calling advanced with increasing moth age. The mating of K. kumaso adults initiated during the first scotophase and terminated till the 5th scotophase following emergence, and the peak of mating was observed during the second scotophase. The peak of mating was observed 5.5-7.0 h after dark, and advanced with increasing moth age. Moth age affected the mean onset time of mating and the copulation duration significantly. With increasing moth age, the mean onset time of mating advanced, and the copulation duration decreased. Sex ratio had significant effects on the mating behavior as well. Treatment 2 female:1 male showed a significantly higher mating percentage, but an earlier onset time of mating and shorter copulation duration, as compared with treatment 1 female:1 male. The results of EAG test indicated that the male adults showed a significant EAG response to the sex gland extracts of 2-day-old virgin females.
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Facile and straightforward synthesis of superparamagnetic reduced graphene oxide-Fe3O4 hybrid composite by a solvothermal reaction.
Nanotechnology
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A superparamagnetic reduced graphene oxide-Fe(3)O(4) hybrid composite (rGO-Fe(3)O(4)) was prepared via a facile and straightforward method through the solvothermal reaction of iron (III) acetylacetonate (Fe(acac)(3)) and graphene oxide (GO) in ethylenediamine (EDA) and water. By this method, chemical reduction of GO as well as the formation of Fe(3)O(4) nanoparticles (NPs) can be achieved in one step. The Fe(3)O(4) NPs are firmly deposited on the surfaces of rGO, avoiding their reassembly to graphite. The rGO sheets prevent the agglomeration of Fe(3)O(4) NPs and enable a uniform dispersion of these metal oxide particles. The size distribution and coverage density of Fe(3)O(4) NPs deposited on rGO can be controlled by varying the initial mass ratio of GO and iron precursor, Fe(acac)(3). With an initial mass ratio of GO and Fe(acac)(3) of 5:5, the surfaces of rGO sheets are densely covered by spherical Fe(3)O(4) NPs with an average size of 19.9 nm. The magnetic-functionalized rGO hybrid exhibits a good magnetic property and the specific saturation magnetization (M(s)) is 13.2 emu g(-1). The adsorption test of methylene blue from aqueous solution demonstrates the potential application of this rGO-Fe(3)O(4) hybrid composite in removing organic dyes from polluted water.
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The protection of acetylcholinesterase inhibitor on ?-amyloid-induced the injury of neurite outgrowth via regulating axon guidance related genes expression in neuronal cells.
Int J Clin Exp Pathol
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Cognitive deficits in AD correlate with progressive synaptic dysfunction and loss. The Rho family of small GTPases, including Rho, Rac, and Cdc42, has a central role in cellular motility and cytokinesis. Acetylcholinesterase inhibitor has been found to protect cells against a broad range of reagents-induced injuries. Present studies examined if the effect of HupA on neurite outgrowth in A?-treated neuronal cells executed via regulating Rho-GTPase mediated axon guidance relative gene expression. Affymetrix cDNA microarray assay followed by real-time RT-PCR and Western Blotting analysis were used to elucidate and analyze the signaling pathway involved in A? and HupAs effects. The effects of A? and HupA on the neurite outgrowth were further confirmed via immunofluorescence staining. A? up-regulated the mRNA expressions of NFAT5, LIMK1, EPHA1, NTN4 and RAC2 markedly in SH-SY5Y cells. Co-incubation of A? and HupA reversed or decreased the changes of NFAT5, NTN4, RAC2, CDC42 and SEMA4F. HupA treated alone increased NFAT5, LIMK1, NTN4 significantly. Following qRT-PCR validation showed that the correlation of the gene expression ratio between microarray and qRT-PCR is significant. Western blot result showed that the change of CDC42 protein is consistent with the mRNA level while RAC2 is not. The morphological results confirmed that HupA improved, or partly reversed, the A?-induced damage of neurite outgrowth. The protective effect of HupA from A? induced morphological injury might be correlative to, at least partially, regulating the network of neurite outgrowth related genes.
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Vav1 in hematologic neoplasms, a mini review.
Am J Blood Res
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The Vav family of proteins are guanine nucleotide exchange factors which have been shown to be deregulated in several types of human cancer. There are three members of the Vav family that have been identified which are members of the Dbl domain superfamily and have specificity towards Rho/Rac GTPases. The Vav family plays an important role in normal hematologic system development and homeostasis, and Vav1 is largely restricted to the hematologic system. While Vav1 was originally identified as a proto-oncogene, several recent studies have shown that Vav family deletion leads to the development of T-cell malignancies in mice. In addition, Vav1 has been shown to play a role in the ATRA-mediated differentiation of promyelocytic leukemia cells. In this concise review, the gene structure and normal function of Vav1, as well as a possible role for Vav1 in the development of hematologic and other malignancies is reviewed.
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Activation of boron nitride nanotubes and their polymer composites for improving mechanical performance.
Nanotechnology
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Boron nitride nanotubes (BNNTs) are inappropriate for further chemical derivatization because of their chemical inertness. We demonstrate covalent activation of chemically inert BNNTs by isophorone diisocyanate (IPDI) to form isocyanate group (NCO)-terminated BNNT precursors with an NCO anchor ready for further functionalization. As identified by Fourier transform infrared spectroscopy, a number of molecules or polymers with -COOH, -OH or -NH? groups are readily attached to the activated IPDI-BNNTs. The IPDI-BNNT-involving polymer composites have shown mechanical properties are considerably improved due to the good dispersibility of IPDI-BNNTs in the polymer matrix and the strong interfacial interactions between BNNTs and polymers. The methodology reported here provides a promising method to promote the chemical reactivity of BNNTs and covalently modify polymer nanocomposites with improved mechanical performance.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.