Bubble bursting is a primary source of marine aerosols, yet little is known about particle emissions due to the bubble bursting in slicks containing oil‐dispersant mixtures. In this study, bubbles ...with mode sizes of 86 μm (denoted as small), 178 μm (medium), and 595 μm (large) are injected into a seawater column covered by slicks of crude oil, pure dispersant, and dispersant premixed with oil at a ratio of 1:25. The aerosol size distributions are monitored in the 0.5‐ to 20‐μm and 10‐ to 380‐nm ranges both in clean and ambient air environments. In ambient air, a tenfold increase in submicron particle concentration occurs when large bubbles burst on slicks of 500‐μm dispersant premixed with oil at a ratio of 1:25 oil or 50‐μm pure dispersant. Yet, in multiple tests performed at different ambient particle concentrations, the elevated size distributions persistently maintain the same shape as that of the ambient air. In contrast, smaller bubbles and tests not involving dispersants do not cause such an increase. Nanodroplets are also generated by large bubbles in particle‐free air, but their concentrations are much lower. All plumes generate micron‐sized aerosols, but trends vary. For the same contaminant, the microdroplet concentration decreases with increasing slick thickness. Particularly striking is a reduction of 2 orders of magnitude in the microdroplet concentration when medium and small bubbles burst on 500‐μm crude oil slicks. Chemical analysis of air and particulates collected from filters sampling the particles confirms the presence of airborne oil above the slicks.
Key Points
Bursting of bubbles in slicks containing crude oil and dispersant mixtures aerosolizes the oil, generating microdroplets and nanodroplets
In ambient air, a tenfold increase in submicron particle concentration occurs when large bubbles burst on slicks containing dispersants
Microdroplets are generated for all bubble plumes and slick types, but their concentration decreases with increasing slick thickness
Shifts in electrostatic surface charge of membranes have recently been highlighted as a significant factor contributing to protein targeting to the plasma membrane and nascent phagosomes. ...Intracellular, vacuole-adapted pathogens may also regulate surface charge of their vacuoles to establish a replicative niche. Since Salmonella enterica serovar Typhimurium controls trafficking of the Salmonella-containing vacuole (SCV) and inhibits its fusion with lysosomes, we investigated the contribution of surface charge to this process. Using recently developed fluorescent biosensors, we show that the bacterial phosphoinositide phosphatase SopB controls membrane surface charge of nascent SCVs by reducing levels of negatively charged lipids phosphatidylinositol-4,5-bisphosphate and phosphatidylserine. This SopB activity results in dissociation of a number of host-cell endocytic trafficking proteins from this compartment and inhibits SCV-lysosome fusion. Moreover, inducible reduction of negative charge rescues DeltasopB bacteria-containing SCVs from fusion with lysosomes. These results reveal a membrane-charge-based mechanism used by S. Typhimurium to control SCV maturation.
Disaster and safety management budgets should be managed efficiently through suitability verification. However, no method has been proposed for efficiency verification in the existing research due to ...limited budget data and absence of a verification decision method. In this study, efficiency was verified by matrix analysis to determine if the disaster and safety management budgets of 16 local governments in South Korea were invested efficiently. Algorithms using the budget data were developed, and case studies conducted on regional budget and damage status data from 16 regions over the past 10 years. The matrix analysis applied the trend of the damage amount and disaster management budget, and results were divided into low- and high-risk groups according to budget and damage status. Results showed that areas in high-risk groups comprise a smaller proportion of the budget, or that the budget was not allocated efficiently. The scale and direction of budgets have been readjusted by applying the algorithms proposed in this study to move the areas from high-risk to low-risk groups. As a result of the readjustment, a risk-reducing effect was identified. Through this study, the efficiency of regions’ disaster management budgets can be improved, contributing to damage reduction. It can contribute to the efficient operation of the budget and the reduction of the damage by identifying areas in which the damage occurs and ensuring that the budget is properly invested in those areas.
Proteinopathy in neurodegenerative diseases is typically characterized by deteriorating activity of specific protein aggregates. In tauopathies, including Alzheimer's disease (AD), tau protein ...abnormally accumulates and induces dysfunction of the affected neurons. Despite active identification of tau modifications responsible for tau aggregation, a critical modulator inducing tau proteinopathy by affecting its protein degradation flux is not known. Here, we report that anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase, is crucial for the tau-mediated AD pathology. ALK caused abnormal accumulation of highly phosphorylated tau in the somatodendritic region of neurons through its tyrosine kinase activity. ALK-induced LC3-positive axon swelling and loss of spine density, leading to tau-dependent neuronal degeneration. Notably, ALK activation in neurons impaired Stx17-dependent autophagosome maturation and this defect was reversed by a dominant-negative Grb2. In a Drosophila melanogaster model, transgenic flies neuronally expressing active Drosophila Alk exhibited the aggravated tau rough eye phenotype with retinal degeneration and shortened lifespan. In contrast, expression of kinase-dead Alk blocked these phenotypes. Consistent with the previous RNAseq analysis showing upregulation of ALK expression in AD 1, ALK levels were significantly elevated in the brains of AD patients showing autophagosomal defects. Injection of an ALK.Fc-lentivirus exacerbated memory impairment in 3xTg-AD mice. Conversely, pharmacologic inhibition of ALK activity with inhibitors reversed the memory impairment and tau accumulation in both 3xTg-AD and tauC3 (caspase-cleaved tau) transgenic mice. Together, we propose that aberrantly activated ALK is a bona fide mediator of tau proteinopathy that disrupts autophagosome maturation and causes tau accumulation and aggregation, leading to neuronal dysfunction in AD.
Sepsis has a high mortality rate, but no specific drug has been proven effective, prompting the development of new drugs. Immunologically, sepsis can involve hyperinflammation, immune paralysis, or ...both, which might pose challenges during drug development. Recently, mitochondrial transplantation has emerged as a treatment modality for various diseases involving mitochondrial dysfunction, but it has never been tested for sepsis.
We isolated mitochondria from L6 muscle cells and umbilical cord mesenchymal stem cells and tested the quality of the isolated mitochondria. We conducted both in vivo and in vitro sepsis studies. We investigated the effects of intravenous mitochondrial transplantation on cecal slurry model in rats in terms of survival rate, bacterial clearance rate, and the immune response. Furthermore, we observed the effects of mitochondrial transplantation on the immune reaction regarding both hyperinflammation and immune paralysis. To do this, we studied early- and late-phase cytokine production in spleens from cecal slurry model in rats. We also used a lipopolysaccharide (LPS)-stimulated human PBMC monocyte model to confirm the immunological effects of mitochondrial transplantation. Apoptosis and the intrinsic apoptotic pathway were investigated in septic spleens.
Mitochondrial transplantation improved survival and bacterial clearance. It also mitigated mitochondrial dysfunction and apoptosis in septic spleens and attenuated both hyperinflammation and immune paralysis in the spleens of cecal slurry model in rats. This effect was confirmed with an LPS-stimulated human PBMC study.
In rat polymicrobial cecal slurry model, the outcome is improved by mitochondrial transplantation, which might have an immunomodulatory effect.
Types of mechanoreceptors may differ between the medial and lateral menisci, suggesting that postural stability may differ between patients with medial and lateral meniscus tears. However, to date, ...postural stability has not been compared in patients with medial and lateral meniscus tears. This study used stabilometry to compare postural stability in patients with medial and lateral meniscus tears.
Postural stability and thigh muscle strength were assessed in 24 patients with medial and 18 patients with lateral meniscus tears. Postural stability was determined by measuring the anteroposterior (APSI), mediolateral (MLSI), and overall (OSI) stability indices using stabilometry. Maximal torque (60°/s) of the quadriceps and hamstring was evaluated using an isokinetic testing device.
The three stability indices, OSI, APSI, and MLSI, in both involved and uninvolved knees were all significantly greater in patients with lateral than with medial meniscus tears.
(P<0.001 for all OSI, APSI, and MLSI in both involved and uninvolved knees, except for P=0.005 for MLSI of involved knees). In patients with medial meniscus tears, both OSI (1.4±0.4 vs. 1.1±0.4, P=0.037) and MLSI (0.9±0.3 vs. 0.8±0.3, P=0.041) were significantly higher on the injured than the uninjured side. In patients with lateral meniscus tears, none of the stability indices differed significantly between injured and uninjured knee joints.
Postural stability of both the injured and uninjured knee joints was poorer in patients with lateral than with medial meniscus tears.
Sarcopenia is defined as the involuntary loss of skeletal muscle mass and function with aging and is associated with several adverse health outcomes. Recently, the disruption of regular circadian ...rhythms, due to shift work or nocturnal lifestyle, is emerging as a novel deleterious factor for the development of sarcopenia. The underlying mechanisms responsible for circadian disruption-induced sarcopenia include molecular circadian clock and mitochondrial function associated with the regulation of circadian rhythms. Exercise is a potent modulator of skeletal muscle metabolism and is considered to be a crucial preventative and therapeutic intervention strategy for sarcopenia. Moreover, emerging evidence shows that exercise, acting as a zeitgeber (time cue) of the skeletal muscle clock, can be an efficacious tool for re-setting the clock in sarcopenia. In this review, we provide the evidence of the impact of circadian disruption on skeletal muscle loss resulting in sarcopenia. Furthermore, we highlight the importance of exercise timing (i.e., scheduled physical activity) as a novel therapeutic strategy to target circadian disruption in skeletal muscle.
We investigated the effects of a potential probiotic strain Lactococcus lactis subsp. lactis I2 on the immune response and growth of olive flounder (Paralichthys olivaceus), and their capacity to ...prevent streptococcosis after Streptococcus iniae challenge. The L. lactis subsp. lactis I2 strain, isolated from olive flounder intestine, was supplemented orally as a feed additive (~108CFUg−1) to fish for 5weeks. Compared with the untreated group, the rate of growth was increased in the I2-diet group. The administration of I2 to olive flounder enhanced non-specific immune parameters, such as lysozyme, antiprotease, serum peroxidase and blood respiratory burst activities. At 9days after challenge with S. iniae (108CFU), the untreated control group experienced a 90% mortality rate, whereas all of the I2-cell-supplemented fish survived. These results show that L. lactis subsp. lactis I2 exerted beneficial effects as a probiotic and has potential as an alternative to antibiotics for the prevention of streptococcosis in aquaculture.
► The growth rate of fish was increased in the I2-cell supplemented group. ► Non-specific immune parameters enhanced in fish supplemented with I2-cell. ► 100% survivability was observed in I2-group after challenge with S. iniae.
Protein homo-oligomerization is an important molecular mechanism in many biological processes. Therefore, the ability to control protein homo-oligomerization allows the manipulation and interrogation ...of numerous cellular events. To achieve this, cryptochrome 2 (CRY2) from Arabidopsis thaliana has been recently utilized for blue light-dependent spatiotemporal control of protein homo-oligomerization. However, limited knowledge on molecular characteristics of CRY2 obscures its widespread applications. Here, we identify important determinants for efficient cryptochrome 2 clustering and introduce a new CRY2 module, named ''CRY2clust'', to induce rapid and efficient homo-oligomerization of target proteins by employing diverse fluorescent proteins and an extremely short peptide. Furthermore, we demonstrate advancement and versatility of CRY2clust by comparing against previously reported optogenetic tools. Our work not only expands the optogenetic clustering toolbox but also provides a guideline for designing CRY2-based new optogenetic modules.Cryptochrome 2 (CRY2) from A. thaliana can be used to control light-dependent protein homo-oligomerization, but the molecular mechanism of CRY2 clustering is not known, limiting its application. Here the authors identify determinants of CRY2 clustering and engineer fusion partners to modulate clustering efficiency.
Members of the Rab guanosine triphosphatase (GTPase) family are key regulators of membrane traffic. Here we examined the association of 48 Rabs with model phagosomes containing a non-invasive mutant ...of Salmonella enterica serovar Typhimurium (S. Typhimurium). This mutant traffics to lysosomes and allowed us to determine which Rabs localize to a maturing phagosome. In total, 18 Rabs associated with maturing phagosomes, each with its own kinetics of association. Dominant-negative mutants of Rab23 and 35 inhibited phagosome-lysosome fusion. A large number of Rab GTPases localized to wild-type Salmonella-containing vacuoles (SCVs), which do not fuse with lysosomes. However, some Rabs (8B, 13, 23, 32, and 35) were excluded from wild-type SCVs whereas others (5A, 5B, 5C, 7A, 11A, and 11B) were enriched on this compartment. Our studies demonstrate that a complex network of Rab GTPases controls endocytic progression to lysosomes and that this is modulated by S. Typhimurium to allow its intracellular growth.
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