The complete mitochondrial genome of Siganus virgatus Valenciennes (Siganidae: Acanthuriformes).

Siganus virgatus Valenciennes 1835 is an essential species for examining reef ecosystems; however, its mitochondrial genome has not been studied. In this research, the mitogenome of S. virgatus was sequenced and characterized. The results revealed a circular genome of 16,505 bp that was composed of A (28.1%), C (31.3%), G (14%), and T nucleotides (26.6%). The genome contained 13 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. Most genes of the mitogenome were transcribed on the heavy strand (H-strand), whereas ND6 and eight tRNA genes (including tRNA-Ala, -Asn, -Cys, -Gln, -Glu, -Ser (1), -Pro, and -Tyr) were transcribed on the light strand (L-strand). Comparative analysis revealed a high degree of conservation of gene content and order among the Siganus mitogenomes. Phylogenetic analysis inferred from whole mitogenomes exhibited a close relationship between S. virgatus and S. guttatus. The newly completed mitogenome of S. virgatus provides essential genomic data for further studies on population genetics and the evolution of the Siganus genus and the Siganidae family.

Challenges in diagnosis and management of central airway obstruction: Case series.

Central airway obstruction often presents with respiratory symptoms identical to those of common respiratory diseases. Diagnosis of central airway obstruction is challenging in clinical practice, especially misdiagnosed as asthma or chronic obstructive pulmonary disease in case of "normal" chest X-ray. Here, we reported five central airway obstruction cases: the first and fourth cases misdiagnosed as asthma, the second masquerading as chronic obstructive pulmonary disease exacerbation, the third diagnosed incorrectly with non-resolving pneumonia, and the fifth misdiagnosed as chronic obstructive pulmonary disease. We then analyzed diagnostic clues potentially useful to differentiate central airway obstruction from asthma/chronic obstructive pulmonary disease. A multidisciplinary approach to manage central airway obstruction is essential, particularly selecting judiciously the method of respiratory support due to the high risk of completed airway collapse or obstruction during interventional period.

Factors Contributing to Accumulation of 210Po in Freshwater Fishes in Dong Thai Lake, Vietnam and Radiological Hazard Assessment.

210Po (polonium), one of the most toxic naturally occurring radionuclides, is well-known as a common natural radionuclide in fish species. Human consumption of 210Po-contaminated fish could result in a significant internal dose. This study determined by alpha spectrometry the 210Po activity in sixteen selected fish species with different living behaviors (pelagic, demersal), trophic positions (herbivores, carnivores, omnivorous), and masses in Dong Thai Lake, Hanoi, Vietnam. The min, max, and average of the 210Po concentration of sixteen fish species were 0.80 ± 0.44, 12.7 ± 0.20, and 3.54 ± 0.31 Bq kg-1, respectively. Regarding the different living behaviors, trophic positions, and masses, the results showed trending of 210Popelagic > 210Podemersal; 210Poherbivores < 210Pocarnivores < 210Poomnivorous and 210Po<0.2 kg > 210Po0.2-1 kg > 210Po>1 kg, respectively. The 210Po concentrations in muscle tissue were greater in fish species with a small mass, omnivorous trophic position, and pelagic living behavior relative to demersal fish with a larger mass that were herbivores or carnivores. In addition, the results showed an uneven distribution of 210Po activities in atmospheric aerosols, terrestrial soils, surface waters, and lake sediments in the study area. The primary source of 210Po could be supplied from atmospheric aerosols and/or terrestrial soils in the study area. The 210Po annual effective dose for adults due to fish consumption has been calculated with a range from 20 to 400 µSv y-1 and 111 µSv. y-1 on average, and it is far below the allowable limits of 1000 µSv y-1.

Characteristics of 210Po in Asian overbite clam (Potamocorbula laevis) from the coastal area at Thai Binh province, Vietnam.

210Po concentration in the edible muscle tissue and digestive diverticulum organs of Asian overbite clam at the near-shore Thai Binh, Vietnam was analyzed using alpha detectors. The 210Po activity in muscle tissue and digestive diverticulum organs ranged from 5 ± 1 to 178 ± 10 and from 118 ± 7 to 812 ± 12 Bq.kg-1 with the average value of 25 and 324 Bq.kg-1, respectively. Results showed that 210Po activity in the digestive diverticulum was significantly higher than in the muscle tissue. There was a slightly inverse correlation between 210Po activity in muscle tissue, digestive diverticulum, and clam weight and size. The annual committed effective dose was calculated from 210Po due to the consumption of Asian overbite clam for adults in the study area was higher than the guideline value of 0.2 - 1 mSv.y-1.

Gross beta and alpha activities in the selected commercial freshwater fish species in Vietnam.

The baseline data of radioactivity levels in food is one of the main factors for the assessment of resident's health risk. Gross beta and alpha activity was identified for selected commercial freshwater fish species, including 29 types of fish species by a gas-flow proportional detector. The samples were collected from wholesale markets in Hanoi city, Vietnam. The highest gross alpha activity was recorded in blotched snakehead, a pelagic and carnivorous species, and the lowest one was recorded in common carp, a demersal and omnivorous species. Meanwhile, the gross beta activity was much higher than the gross alpha activity with the highest value of gross beta, observed in Wels catfish, a demersal and carnivorous species, and the lowest one found in Mudskipper a demersal, herbivores species. Regarding feeding types, the gross alpha activity was observed in the order of Alcarnivores > Alomnivores > Alherbivores whereas the gross beta was non-distinction. In terms of living behavior, the gross alpha activity in pelagic species was much higher than that in demersal species (Alpelagic > > Aldemersal) and indifferent for gross beta. There was an insignificant relationship between the trophic level with gross beta and alpha activities in freshwater fish species. The calculated annual effective dose ​​ranged from 0.19 to 1.88 and 0.78 mSv.y-1 on average, being within the limited dose for the public as reported by UNSCEAR in which gross beta activity has a strong correlation with the total annual effective dose.

Distribution and annual committed effective dose assessment of 210Po in popular marine species at the near-shore Binh Thuan province, Vietnam.

210Po concentration in thirty popular marine species (twenty five fishes, four bivalves and one crab) with different habitats, feeding types, and trophic levels at the near-shore Binh Thuan, Vietnam was analyzed using the alpha detectors. The 210Po activities were widely ranged from 3.07 ± 0.18 in a fish species (Bumpnose trevally) to 78.6 ± 5.3 Bq/kg w.w in a bivalve species (Green mussel) with the average value of 16.6 Bq/kg w.w. The results showed that the species with lower trophic level value have higher 210Po concentration. Regarding the feeding types, the 210Po concentration in the omnivorous species is about 2.9 times higher than in the carnivorous species. The species living in demersal zone accumulated a high 210Po in comparison with species living in reef-associated and pelagic-neritic zones. The calculated annual committed effective dose from 210Po due to the ingestion of seafood from demersal zone and bivalve species of the area was significant high.

Simulation exercises and after action reviews - analysis of outputs during 2016-2019 to strengthen global health emergency preparedness and response.

BACKGROUND: Under the International Health Regulations (2005) [IHR (2005)] Monitoring and Evaluation Framework, after action reviews (AAR) and simulation exercises (SimEx) are two critical components which measure the functionality of a country's health emergency preparedness and response under a "real-life" event or simulated situation. The objective of this study was to describe the AAR and SimEx supported by the World Health Organization (WHO) globally in 2016-2019. METHODS: In 2016-2019, WHO supported 63 AAR and 117 SimEx, of which 42 (66.7%) AAR reports and 56 (47.9%) SimEx reports were available. We extracted key information from these reports and created two central databases for AAR and SimEx, respectively. We conducted descriptive analysis and linked the findings according to the 13 IHR (2005) core capacities. RESULTS: Among the 42 AAR and 56 SimEx available reports, AAR and SimEx were most commonly conducted in the WHO African Region (AAR: n = 32, 76.2%; SimEx: n = 32, 52.5%). The most common public health events reviewed or tested in AAR and SimEx, respectively, were epidemics and pandemics (AAR: n = 38, 90.5%; SimEx: n = 46, 82.1%). For AAR, 10 (76.9%) of the 13 IHR core capacities were reviewed at least once, with no AAR conducted for food safety, chemical events, and radiation emergencies, among the reports available. For SimEx, all 13 (100.0%) IHR capacities were tested at least once. For AAR, the most commonly reviewed IHR core capacities were health services provision (n = 41, 97.6%), risk communication (n = 39, 92.9%), national health emergency framework (n = 39, 92.9%), surveillance (n = 37, 88.1%) and laboratory (n = 35, 83.3%). For SimEx, the most commonly tested IHR core capacity were national health emergency framework (n = 56, 91.1%), followed by risk communication (n = 48, 85.7%), IHR coordination and national IHR focal point functions (n = 45, 80.4%), surveillance (n = 31, 55.4%), and health service provision (n = 29, 51.8%). For AAR, the median timeframe between the end of the event and AAR was 125 days (range = 25-399 days). CONCLUSIONS: WHO has recently published guidance for the planning, execution, and follow-up of AAR and SimEx. Through the guidance and the simplified reporting format provided, we hope to see more countries conduct AAR and SimEx and standardization in their methodology, practice, reporting and follow-up.

Adaptive dynamics of hematopoietic stem cells and their supporting stroma: a model and mathematical analysis.

We propose a mathematical model to describe the evolution of hematopoietic stem cells (HSCs) and stromal cells in considering the bi-directional interaction between them. Cancerous cells are also taken into account in our model. HSCs are structured by a continuous phenotype characterising the population heterogeneity in a way relevant to the question at stake while stromal cells are structured by another continuous phenotype representing their capacity of support to HSCs. We then analyse the model in the framework of adaptive dynamics. More precisely, we study single Dirac mass steady states, their linear stability and we investigate the role of parameters in the model on the nature of the evolutionary stable distributions (ESDs) such as monomorphism, dimorphism and the uniqueness properties. We also study the dominant phenotypes by an asymptotic approach and we obtain the equation for dominant phenotypes. Numerical simulations are employed to illustrate our analytical results. In particular, we represent the case of the invasion of malignant cells as well as the case of co-existence of cancerous cells and healthy HSCs.

Dispersal towards food: the singular limit of an Allen-Cahn equation.

The effect of dispersal under heterogeneous environment is studied in terms of the singular limit of an Allen-Cahn equation. Since biological organisms often slow down their dispersal if food is abundant, a food metric diffusion is taken to include such a phenomenon. The migration effect of the problem is approximated by a mean curvature flow after taking the singular limit which now includes an advection term produced by the spatial heterogeneity of food distribution. It is shown that the interface moves towards a local maximum of the food distribution. In other words, the dispersal taken in the paper is not a trivialization process anymore, but an aggregation one towards food.

Modal decomposition technique for multimode fibers.

We propose a new solution for modal decomposition in multimode fibers, based on a spectral and spatial imaging technique. The appearance of spurious modes in the spectral and spatial processing of the images at the output of the fiber under test when it has more than two modes is demonstrated theoretically. The new method, which allows us to identify spurious modes, is more accurate, simpler, and faster than previously reported methods. For demonstration, measurements in a standard step-index multimode fiber and a small-core microstructured fiber are carried out successfully.

Self-phase-modulation-based 2R regenerator including pulse compression and offset filtering for 42.6 Gbit/s RZ-33% transmission systems.

We report on the experimental and theoretical study of a self-phase-modulation-based regenerator at 42.6 Gbit/s with a return-to-zero 33% format. We point out some detrimental effects such as intrachannel interactions and Brillouin scattering. An efficient solution, relying on a self-phase-modulation-based pulse compressor in combination with the regenerator, is proposed to overcome these detrimental phenomena. The experimental demonstration shows the effectiveness of a wavelength-transparent regenerator at 42.6 Gbit/s with a sensitivity-improvement of more than 5 dB and an eye-opening improvement of 2.3 dB in a back-to-back configuration, as well as a 10 times maximum transmission distance improvement for a BER of 10(-4).