2,901 research outputs found
Paxillin facilitates timely neurite initiation on soft-substrate environments by interacting with the endocytic machinery.
Neurite initiation is the first step in neuronal development and occurs spontaneously in soft tissue environments. Although the mechanisms regulating the morphology of migratory cells on rigid substrates in cell culture are widely known, how soft environments modulate neurite initiation remains elusive. Using hydrogel cultures, pharmacologic inhibition, and genetic approaches, we reveal that paxillin-linked endocytosis and adhesion are components of a bistable switch controlling neurite initiation in a substrate modulus-dependent manner. On soft substrates, most paxillin binds to endocytic factors and facilitates vesicle invagination, elevating neuritogenic Rac1 activity and expression of genes encoding the endocytic machinery. By contrast, on rigid substrates, cells develop extensive adhesions, increase RhoA activity and sequester paxillin from the endocytic machinery, thereby delaying neurite initiation. Our results highlight paxillin as a core molecule in substrate modulus-controlled morphogenesis and define a mechanism whereby neuronal cells respond to environments exhibiting varying mechanical properties
By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans.
Pigmentation evolved in ancestral humans to protect against toxic, ultraviolet B irradiation, but the question remains: "what is being protected?" Because humans with dark pigmentation display a suite of superior epidermal functions in comparison with their more lightly pigmented counterparts, we hypothesized and provided evidence that dark pigmentation evolved in Africa to support cutaneous function. Because our prior clinical studies also showed that a restoration of a competent barrier dampens cutaneous inflammation, we hypothesized that resistance to inflammation could have provided pigmented hominins with yet another, important evolutionary benefit. We addressed this issue here in two closely related strains of hairless mice, endowed with either moderate (Skh2/J) or absent (Skh1) pigmentation. In these models, we showed that (a) pigmented mice display a markedly reduced propensity to develop inflammation after challenges with either a topical irritant or allergen in comparison with their nonpigmented counterparts; (b) visible and histologic evidence of inflammation was paralleled by reduced levels of pro-inflammatory cytokines (i.e., IL-1α and INFα); (c) because depigmentation of Skh2/J mouse skin enhanced both visible inflammation and pro-inflammatory cytokine levels after comparable pro-inflammatory challenges, the reduced propensity to develop inflammation was directly linked to the presence of pigmentation; and (d) furthermore, in accordance with our prior work showing that pigment production endows benefits by reducing the surface pH of skin, acidification of albino (Skh1) mouse skin also protected against inflammation, and equalized cytokine levels to those found in pigmented skin. In summary, pigmentation yields a reduced propensity to develop inflammation, consistent with our hypothesis that dark pigmentation evolved in ancestral humans to provide a suite of barrier-linked benefits that now include resistance to inflammation
Langerhans cell hyperplasia in the tumor stage of mycosis fungoides: a mimic of Langerhans cell histiocytosis
AbstractMycosis fungoides is a form of cutaneous T-cell lymphoma (CTCL). Malignant CD4+ T cells have been found to adopt the T-regulatory (Treg) cell phenotype and function. We present the case of a 66-year-old man diagnosed with mycosis fungoides that was progressing from the plaque to the tumor stage. The histopathological examinations showed that the Langerhans cell (LC) infiltration in the skin lesion of the tumor stage was greater than that in the patch/plaque stage; the tumor stage lesions resembled LC histiocytosis pathologically. The associations among LCs, apoptotic tumor cells, Treg CTCL cells, and relevant cytokines are complex. Treg CTCL cells produce the immunosuppressive cytokines interleukin-10 and transforming growth factor beta, which facilitate continuous recruitment of LCs and maintenance of long-term dendritic cell immaturity, thereby explaining the remarkable LC infiltration in the tumor stage samples from our patient. This phenomenon indicates that LCs accompanied by Treg CTCL cells may play an important synergistic role in the tumor progression. The development of immunotherapy directed against Treg CTCL cells and LCs overproduction and other immunosuppressive cytokines may be a potent useful adjuvant and worthy of further investigation
The mPEG-PCL Copolymer for Selective Fermentation of Staphylococcus lugdunensis Against Candida parapsilosis in the Human Microbiome.
Many human skin diseases, such as seborrheic dermatitis, potentially occur due to the over-growth of fungi. It remains a challenge to develop fungicides with a lower risk of generating resistant fungi and non-specifically killing commensal microbes. Our probiotic approaches using a selective fermentation initiator of skin commensal bacteria, fermentation metabolites or their derivatives provide novel therapeutics to rein in the over-growth of fungi. Staphylococcus lugdunensis (S. lugdunensis) bacteria and Candida parapsilosis (C. parapsilosis) fungi coexist in the scalp microbiome. S. lugdunensis interfered with the growth of C. parapsilosis via fermentation. A methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG-PCL) copolymer functioned as a selective fermentation initiator of S. lugdunensis, selectively triggering the S. lugdunensis fermentation to produce acetic and isovaleric acids. The acetic acid and its pro-drug diethyleneglycol diacetate (Ac-DEG-Ac) effectively suppressed the growth of C. parapsilosis in vitro and impeded the fungal expansion in the human dandruff. We demonstrate for the first time that S. lugdunensis is a skin probiotic bacterium that can exploit mPEG-PCL to yield fungicidal short-chain fatty acids (SCFAs). The concept of bacterial fermentation as a part of skin immunity to re-balance the dysbiotic microbiome warrants a novel avenue for studying the probiotic function of the skin microbiome in promoting health
Does Product Type Affect Electronic Word-of-Mouth Richness Effectiveness? Influences of Message Valence and Consumer Knowledge
Drawing on the information richness theory, this study attempts to address how valence of electronic word-of-mouth (eWOM), product type and consumer knowledge will yield different levels of eWOM richness. The results based on an experimental study suggest that negative eWOM has a stronger effect in producing eWOM information richness than does positive eWOM, and such effect is more pronounced for a leisure farm tour (experience goods) than for digital camera (search goods). The tendency that negative eWOM will provide richer information for the leisure farm tour is more evident for high-knowledge consumers than for low-knowledge consumers. The study’s results caution against the aggravated harm of negative eWOM incurred from the dissatisfactory experience of a leisure farm tour
Pengembangan Suplemen Pembelajaran Fisika Gelombang Elektromagnetik Cahaya Sebagai Partikel Memanfaatkan Virtual Laboratorium
This research has been done to make a supplement for physics learning about light electromagnetic wave as a particle using virtual laboratory. The population of this research was the second year science-students at SMA Muhammadiyah 1 Metro. This development is begun by needs analysis, then identification of resource which is the background of this developmental research. The next step is, identifying the product specification then developing products which contained a tutorial book for teacher and a work sheet for student (LKS). The material and design expert test result is that those products were approved. The external test resulted by users show that the LKS was attractive, very easy to use, and useful. It also was effective to be used as a learning resource because 80% of students reached the passing grade.Telah dilakukan penelitian untuk mengembangkan suplemen pembelajaran fisika gelombang elektromagnetik cahaya sebagai partikel dengan memanfaatkan virtual laboratorium. Populasi penelitian pengembangan ini adalah siswa kelas XI IPA di SMA Muhammadiyah 1 Metro. Pengembangan ini diawali dengan analisis kebutuhan, kemudian identifikasi sumber daya yang melatar belakangi pengembangan. Langkah selanjutnya identifikasi spesifikasi produk yang dilanjutkan dengan mengembangkan produk berupa LKS untuk siswa dan buku panduan untuk guru. Hasil uji internal oleh ahli materi dan ahli desain menyatakan produk yang dikembangkan layak digunakan sebagai media pembelajaran. Hasil uji eksternal oleh pengguna menunjukkan kualitas media pembelajaran menarik, sangat mudah digunakan, dan bermanfaat serta efektif digunakan sebagai media pembelajaran dengan presentase hasil belajar sebesar 80% siswa telah memenuhi KKM
MelHuBERT: A simplified HuBERT on Mel spectrograms
Self-supervised models have had great success in learning speech
representations that can generalize to various downstream tasks. However, most
self-supervised models require a large amount of compute and multiple GPUs to
train, significantly hampering the development of self-supervised learning. In
an attempt to reduce the computation of training, we revisit the training of
HuBERT, a highly successful self-supervised model. We improve and simplify
several key components, including the loss function, input representation, and
training in multiple stages. Our model, MelHuBERT, is able to achieve favorable
performance on phone recognition, speaker identification, and automatic speech
recognition against HuBERT, while saving 31.2% of the pre-training time, or
equivalently 33.5% MACs per one second speech. The code and pre-trained models
are available in https://github.com/nervjack2/MelHuBERT.Comment: ASRU 202
- …
