Summary
Anthocyanins play a variety of adaptive roles in both vegetative tissues and reproductive organs of plants. The broad functionality of these compounds requires sophisticated regulation of the ...anthocyanin biosynthesis pathway to allow proper localization, timing, and optimal intensity of pigment deposition. While it is well‐established that the committed steps of anthocyanin biosynthesis are activated by a highly conserved MYB‐bHLH‐WDR (MBW) protein complex in virtually all flowering plants, anthocyanin repression seems to be achieved by a wide variety of protein and small RNA families that function in different tissue types and in response to different developmental, environmental, and hormonal cues. In this review, we survey recent progress in the identification of anthocyanin repressors and the characterization of their molecular mechanisms. We find that these seemingly very different repression modules act through a remarkably similar logic, the so‐called ‘double‐negative logic’. Much of the double‐negative regulation of anthocyanin production involves signal‐induced degradation or sequestration of the repressors from the MBW protein complex. We discuss the functional and evolutionary advantages of this logic design compared with simple or sequential positive regulation. These advantages provide a plausible explanation as to why plants have evolved so many anthocyanin repressors.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Chronic non-healing wounds have become a major worldwide healthcare burden. The impact of biofilms on chronic wound infection is well established. Despite increasing understanding of the underlying ...mechanism of biofilm formation in chronic wounds, current strategies for biofilm diagnosis in chronic wounds are still far from ideal. In this review, we briefly summarize the mechanism of biofilm formation and focus on current diagnostic approaches of chronic wound biofilms based on morphology, microbiology, and molecular assays. Innovative biotechnological approaches, such as wound blotting and transcriptomic analysis, may further shed light on this unmet clinical need. The continuous development of these sophisticated diagnostic approaches can markedly contribute to the future implementation of point-of-care biofilm detection in chronic wound care.
The impact of biofilms on delayed wound healing has drawn increasing attention. Their importance led to the establishment of biofilm-based wound care where chronic wounds are treated using multipronged strategies to remove biofilms over wound beds to facilitate the recovery of epithelial integrity.
Current clinical and preclinical diagnostic techniques fail to accurately identify pathogens and the precise location of biofilms over wound surfaces, rendering timely medical or surgical intervention to eradicate biofilms elusive.
Wound blotting is a novel biotechnology that predicts wound outcomes and localizes biofilms on wound surfaces by determining the distribution pattern of tumor necrosis factor-alpha (TNF-α) and biofilm mucopolysaccharides. The rapid and objective analysis offered by this technique may assist clinicians in treating chronic wound biofilms.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The genetic links among rift magmatism, crustal growth and water–rock interaction are an important issue about mass and heat transfer between mantle and crust during supercontinent breakup. A ...combined study of Hf and O isotopes in zircons from Neoproterozoic granitoids in South China provides evidence for growth and reworking of juvenile and ancient crusts with different styles of water–rock interactions along rift tectonic zones. Two generations of the granitoids show contrasting features in both zircon Hf and O isotope compositions, indicating their distinct petrogenesis. The ∼
825 Ma granitoids exhibit negative
ε
Hf(
t) values of −
3.4
±
0.8 to −
1.6
±
0.8 with old model Hf ages of 1.81
±
0.07 to 1.92
±
0.10 Ga, and high
δ
18O values of 8.7 to 10.4‰. These indicate that the source material of granitoid magmas was derived from melting of Paleoproterozoic basement that has the Hf isotope signature similar to the enriched mantle but experienced chemical weathering process before anatexis. Reworking of ancient crust is demonstrated to occur at ∼
825 Ma in the orogenic collapse zone, with overprinting of subsolidus hydrothermal alteration during magma emplacement. In contrast, the 760–750 Ma bimodal intrusives are characterized by positive
ε
Hf(
t) values of 3.5
±
0.8 to 9.9
±
0.8 with young model Hf ages of 0.94
±
0.06 to 1.18
±
0.06 Ga, and both low and high
δ
18O values of 4.2 to 6.2‰ relative to 5.3
±
0.3‰ for the normal mantle zircon. Prompt reworking of juvenile crust is suggested to occur at ∼
750 Ma in the rifted tectonic zone, with occurrence of supersolidus hydrothermal alteration and local low-
18O magmatism during supercontinent breakup. Contributions of the depleted mantle to their magma sources are contrasting in the two episodes of magmatism in association with breakup of the supercontinent Rodinia. While the change in melt source from the crust to the mantle keeps pace with the advance from continental rifting to supercontinent breakup, significant transport of both heat and material from the depleted mantle to the continental crust only occurred along the active rifting zone. In either case, the growth and reworking of continental crust are episodically associated with rift magmatism.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Four populations of zircons are recognized by U–Pb analyses of the Neoproterozoic Liantuo Formation in the northern part of the Yangtze Block, South China. They are grains of detrital zircon older ...than 3.0 Ga, ca. 2.95 Ga, ca. 1.95 Ga and 820–750 Ma, respectively. The oldest zircon has a U–Pb age of 3802±8 Ma with a εHf(t) value of −0.8 and model Hf ages of 3.96 Ga (TDM1) and 4.00 Ga (TDM2). This demonstrates the existence of 3.8 Ga old crustal remnants in South China, with possible crustal growth as early as 4.0 Ga. A series of 3.3 Ga zircons have positive εHf(t) values as high as 4.2, providing compelling evidence for growth of juvenile crust from a depleted mantle reservoir at Paleoarchean. All the zircons have Archean Hf model ages, with prominent peaks at 3.2 to 3.6 Ga, indicating an important period of crustal growth in this period. The other three zircon populations at ∼2.95 Ga, ∼1.95 Ga and 820–750 Ma have negative εHf(t) values and consistent Archean Hf model ages, suggesting multi-stage episodic reworking of Archean crustal materials. The youngest zircons have U–Pb ages of ∼750 Ma, very close to the deposition time of the Liantuo Formation. This indicates rapid recycling of supracrustal materials in a rift basin, possibly in association with breakup of the supercontinent Rodinia at that time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Rheumatoid arthritis is a chronic systemic autoimmune disease characterized by synovial hyperplasia, inflammatory cell infiltration, and proliferation of inflammatory tissue (angiogranuloma). The ...destruction of joints and surrounding tissues eventually causes joint deformities and dysfunction or even loss. The S100 protein family is one of the biggest subtribes in the calcium-binding protein family and has more than 20 members. The overexpression of most S100 proteins in rheumatoid arthritis is closely related to its pathogenesis. This paper reviews the relationship between S100 proteins and the occurrence and development of rheumatoid arthritis. It will provide insights into the development of new clinical diagnostic markers and therapeutic targets for rheumatoid arthritis.
The purpose of this study is to conduct modeling and simulation to understand the effect of shock-induced mechanical loading, in the form of cavitation bubble collapse, on damage to the brain's ...perineuronal nets (PNNs). It is known that high-energy implosion due to cavitation collapse is responsible for corrosion or surface damage in many mechanical devices. In this case, cavitation refers to the bubble created by pressure drop. The presence of a similar damage mechanism in biophysical systems has long being suspected but not well-explored. In this paper, we use reactive molecular dynamics (MD) to simulate the scenario of a shock wave induced cavitation collapse within the perineuronal net (PNN), which is the near-neuron domain of a brain's extracellular matrix (ECM). Our model is focused on the damage in hyaluronan (HA), which is the main structural component of PNN. We have investigated the roles of cavitation bubble location, shockwave intensity and the size of a cavitation bubble on the structural evolution of PNN. Simulation results show that the localized supersonic water hammer created by an asymmetrical bubble collapse may break the hyaluronan. As such, the current study advances current knowledge and understanding of the connection between PNN damage and neurodegenerative disorders.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Sampling Matters in Deep Embedding Learning Chao-Yuan Wu; Manmatha, R.; Smola, Alexander J. ...
2017 IEEE International Conference on Computer Vision (ICCV),
2017-Oct.
Conference Proceeding
Open access
Deep embeddings answer one simple question: How similar are two images? Learning these embeddings is the bedrock of verification, zero-shot learning, and visual search. The most prominent approaches ...optimize a deep convolutional network with a suitable loss function, such as contrastive loss or triplet loss. While a rich line of work focuses solely on the loss functions, we show in this paper that selecting training examples plays an equally important role. We propose distance weighted sampling, which selects more informative and stable examples than traditional approaches. In addition, we show that a simple margin based loss is sufficient to outperform all other loss functions. We evaluate our approach on the Stanford Online Products, CAR196, and the CUB200-2011 datasets for image retrieval and clustering, and on the LFW dataset for face verification. Our method achieves state-of-the-art performance on all of them.
Although single-atomically dispersed metal-N
on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading ...metal-N
is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N
. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O
reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO
reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N
sites for diverse high-performance applications.
A combined study of internal structure, U–Pb age, and Hf and O isotopes was carried out for metamorphic zircons from ultrahigh-pressure eclogite boudins enclosed in marbles from the Dabie orogen in ...China. CL imaging identifies two types of zircon that are metamorphically new growth and recrystallized domain, respectively. The metamorphic zircons have low Th and U contents with low Th/U ratios, yielding two groups of
206Pb/
238U age at 245
±
3 to 240
±
2
Ma and 226
±
4 to 223
±
2 Ma, respectively. Anomalously high δ
18O values were obtained for refractory minerals, with 9.9 to 21.4‰ for garnet and 16.9‰ for zircon. This indicates that eclogite protolith is sedimentary rocks capable of liberating aqueous fluid for zircon growth during continental subduction-zone metamorphism. Most of the zircons are characterized by very low
176Lu/
177Hf ratios of 0.000001–0.000028, indicating their growth in association with garnet recrystallization. A few of them falling within the older age group have comparatively high
176Lu/
177Hf ratios of 0.000192–0.000383, suggesting their growth prior to the formation of garnet in the late stage of subduction. The variations in the Lu/Hf ratios for zircons can thus be used to correlate with garnet growth during eclogite-facies metamorphism. In either case, the zircons have variable
ε
Hf
(
t) values for individual samples, suggesting that their protolith is heterogeneous in Hf isotope composition with localized fluid availability in the bulk processes of orogenic cycle. Nevertheless, a positive correlation exists between
206Pb/
238U ages and Lu–Hf isotope ratios for the metamorphically recrystallized zircons, suggesting that eclogite-facies metamorphism in the presence of fluid has the identical effect on zircon Lu–Hf and U–Th–Pb isotopic systems. We conclude that the zircons of the older group grew in the presence of fluid during the subduction prior to the onset of peak ultrahigh-pressure metamorphism, whereas the younger zircons grew in the presence of fluid released during the initial exhumation toward high-pressure eclogite-facies regime.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In plants, the carotenoid biosynthesis pathway (CBP) is essential for the production of photosynthetic and protective pigments, plant hormones, and visual/olfactory attractants for animal pollinators ...and seed dispersers. The regulation of carotenoid biosynthesis at the transcriptional level is vitally important for all of these functions and has been the subject of intensive research. Many putative transcriptional regulators, both direct and indirect, have been identified through conventional mutant analysis, transcriptome profiling, yeast one-hybrid screening, and candidate gene approaches. Despite this progress, our understanding of the transcriptional regulation of carotenoid biosynthesis remains fragmented and incomplete. Frequently, a stimulus or regulator is known, but the mechanism by which it affects transcription has not been elucidated. In other cases, mechanisms have been proposed (such as direct binding of a CBP gene promoter by a transcription factor), but function was tested only
or in heterologous systems, making it unclear whether these proteins actually play a role in carotenoid regulation in their endogenous environments. Even in cases where the mechanism is relatively well understood, regulators are often studied in isolation, either in a single plant species or outside the context of other known regulators. This presents a conundrum: why so many candidate regulators but so little consensus? Here we summarize current knowledge on transcriptional regulation of the CBP, lay out the challenges contributing to this conundrum, identify remaining knowledge gaps, and suggest future research directions to address these challenges and knowledge gaps.
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