229 research outputs found
Ecological factors associated with dengue fever in a central highlands Province, Vietnam
<p>Abstract</p> <p>Background</p> <p>Dengue is a leading cause of severe illness and hospitalization in Vietnam. This study sought to elucidate the linkage between climate factors, mosquito indices and dengue incidence.</p> <p>Methods</p> <p>Monthly data on dengue cases and mosquito larval indices were ascertained between 2004 and 2008 in the Dak Lak province (Vietnam). Temperature, sunshine, rainfall and humidity were also recorded as monthly averages. The association between these ecological factors and dengue was assessed by the Poisson regression model with adjustment for seasonality.</p> <p>Results</p> <p>During the study period, 3,502 cases of dengue fever were reported. Approximately 72% of cases were reported from July to October. After adjusting for seasonality, the incidence of dengue fever was significantly associated with the following factors: higher household index (risk ratio [RR]: 1.66; 95% confidence interval [CI]: 1.62-1.70 per 5% increase), higher container index (RR: 1.78; 95% CI: 1.73-1.83 per 5% increase), and higher Breteau index (RR: 1.57; 95% CI: 1.53-1.60 per 5 unit increase). The risk of dengue was also associated with elevated temperature (RR: 1.39; 95% CI: 1.25-1.55 per 2°C increase), higher humidity (RR: 1.59; 95% CI: 1.51-1.67 per 5% increase), and higher rainfall (RR: 1.13; 95% CI: 1.21-1.74 per 50 mm increase). The risk of dengue was inversely associated with duration of sunshine, the number of dengue cases being lower as the sunshine increases (RR: 0.76; 95% CI: 0.73-0.79 per 50 hours increase).</p> <p>Conclusions</p> <p>These data suggest that indices of mosquito and climate factors are main determinants of dengue fever in Vietnam. This finding suggests that the global climate change will likely increase the burden of dengue fever infection in Vietnam, and that intensified surveillance and control of mosquito during high temperature and rainfall seasons may be an important strategy for containing the burden of dengue fever.</p
Giant Spin Seebeck Effect through an Interface Organic Semiconductor
Interfacing an organic semiconductor C60 with a non-magnetic metallic thin
film (Cu or Pt) has created a novel heterostructure that is ferromagnetic at
ambient temperature, while its interface with a magnetic metal (Fe or Co) can
tune the anisotropic magnetic surface property of the material. Here, we
demonstrate that sandwiching C60 in between a magnetic insulator (Y3Fe5O12:
YIG) and a non-magnetic, strong spin-orbit metal (Pt) promotes highly efficient
spin current transport via the thermally driven spin Seebeck effect (SSE).
Experiments and first principles calculations consistently show that the
presence of C60 reduces significantly the conductivity mismatch between YIG and
Pt and the surface perpendicular magnetic anisotropy of YIG, giving rise to
enhanced spin mixing conductance across YIG/C60/Pt interfaces. As a result, a
600% increase in the SSE voltage (VLSSE) has been realized in YIG/C60/Pt
relative to YIG/Pt. Temperature-dependent SSE voltage measurements on
YIG/C60/Pt with varying C60 layer thicknesses also show an exponential increase
in VLSSE at low temperatures below 200 K, resembling the temperature evolution
of spin diffusion length of C60. Our study emphasizes the important roles of
the magnetic anisotropy and the spin diffusion length of the intermediate layer
in the SSE in YIG/C60/Pt structures, providing a new pathway for developing
novel spin-caloric materials
Effects of salinity and alkalinity on growth and survival of all-male giant freshwater prawn (Macrobrachium rosenbergii De Man, 1879) juveniles
All-male giant freshwater prawns (AMGFPs) have been a popular crop cultivated in the Mekong Delta, Vietnam, due to their proven production efficiency compared to all-female or mixed-sex prawn cultures. However, the crucial water quality factors impacting AMGFP aquaculture efficiency have yet to be elaborately investigated. Two separate experiments were randomly arranged with three replicates to evaluate the effects of salinity or alkalinity on the growth and survival of AMGFP juveniles during the grow-out period. The results show that the prawn survival rate in the salinity range of 0â15â° varied from 66.1 to 74.8ïŒ
and in a salinity range of 0â5â° was relatively low compared to the range of 10-15â°; however, the difference was not significant among salinities after 90 days of culture (p > 0.05). All the prawn growth performance parameters significantly decreased with increasing salinities of 0, 5, 10, and 15â° after 30, 60, and 90 days of culture (p 0.05), and both were significantly higher than those at salinities of 10 and 15â° (p < 0.05) after 90 days of culture. In addition, the survival rate reached 82.5â84.4ïŒ
and did not significantly differ among alkalinities of 80, 100, 120, 140, and 160 mgCaCO3 Lâ1. However, the growth performance parameters and yield of AMGFPs at an alkalinity of 160 mg Lâ1 were significantly higher than those at lower alkalinities (80, 100, 120, and 140 mg CaCO3 Lâ1) after 90 days of culture. Therefore, it is recommended that a salinity range of 0â5â° and alkalinity of 160 mgCaCO3 Lâ1 is optimal for the growth-out culture of AMGFP juveniles
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A Schrödinger Equation for Evolutionary Dynamics
We establish an analogy between the FokkerâPlanck equation describing evolutionary landscape dynamics and the Schrödinger equation which characterizes quantum mechanical particles, showing that a population with multiple genetic traits evolves analogously to a wavefunction under a multi-dimensional energy potential in imaginary time. Furthermore, we discover within this analogy that the stationary population distribution on the landscape corresponds exactly to the ground-state wavefunction. This mathematical equivalence grants entry to a wide range of analytical tools developed by the quantum mechanics community, such as the RayleighâRitz variational method and the RayleighâSchrödinger perturbation theory, allowing us not only the conduct of reasonable quantitative assessments but also exploration of fundamental biological inquiries. We demonstrate the effectiveness of these tools by estimating the population success on landscapes where precise answers are elusive, and unveiling the ecological consequences of stress-induced mutagenesisâa prevalent evolutionary mechanism in pathogenic and neoplastic systems. We show that, even in an unchanging environment, a sharp mutational burst resulting from stress can always be advantageous, while a gradual increase only enhances population size when the number of relevant evolving traits is limited. Our interdisciplinary approach offers novel insights, opening up new avenues for deeper understanding and predictive capability regarding the complex dynamics of evolving populations
A Schr\"odinger Equation for Evolutionary Dynamics
We establish an analogy between the Fokker-Planck equation describing
evolutionary landscape dynamics and the Schr\"{o}dinger equation which
characterizes quantum mechanical particles, showing how a population with
multiple genetic traits evolves analogously to a wavefunction under a
multi-dimensional energy potential in imaginary time. Furthermore, we discover
within this analogy that the stationary population distribution on the
landscape corresponds exactly to the ground-state wavefunction. This
mathematical equivalence grants entry to a wide range of analytical tools
developed by the quantum mechanics community, such as the Rayleigh-Ritz
variational method and the Rayleigh-Schr\"{o}dinger perturbation theory,
allowing us to not only make reasonable quantitative assessments but also
explore fundamental biological inquiries. We demonstrate the effectiveness of
these tools by estimating the population success on landscapes where precise
answers are elusive, and unveiling the ecological consequences of
stress-induced mutagenesis -- a prevalent evolutionary mechanism in pathogenic
and neoplastic systems. We show that, even in a unchanging environment, a sharp
mutational burst resulting from stress can always be advantageous, while a
gradual increase only enhances population size when the number of relevant
evolving traits is limited. Our interdisciplinary approach offers novel
insights, opening up new avenues for deeper understanding and predictive
capability regarding the complex dynamics of evolving populations
The Distribution of Dengue Virus Serotype in Quang Nam Province (Vietnam) during the Outbreak in 2018
Objectives: Quang Nam province in the Centre of Vietnam has faced an outbreak of dengue hemorrhagic fever (DHF) in 2018. Although DHF is a recurrent disease in this area, no epidemiological and microbiological reports on dengue virus serotypes have been conducted mainly due to lack of facilities for such a kind of advanced surveillance. The aim of this study was to detect different dengue virus serotypes in patientsâ blood samples. Design and Methods: Suspected cases living in Quang Nam province (Vietnam) and presenting clinical and hematological signs of dengue hemorrhagic fever were included in the study. The screening was performed, and the results were compared by using two methodologies: RT real-time PCR (RT-rPCR) and the Dengue NS1 rapid test. Results: From December 2018 to February 2019, looking both at RT-rPCR [+] and NS1 [+] methodologies, a total of 488 patients were screened and 336 were positive for dengue virus detection (74 children and 262 adults); 273 of these patients (81.3%) underwent viral serotype identification as follows: 12.82% (35/273) D1 serotype, 17.95% (49/273) D2, 0.37% (1/273) D3, 68.50 (187/283) D4, and 0.37% (1/273) D2+D4 serotypes. The RT-rPCR outcomes showed higher sensitivity during the first three days of infection compared to NS1 (92.3% vs. 89.7%). The NS1 increased sensitivity after the first 3 days whilst the RT-rPCR decreased. Conclusions: Advanced surveillance with dengue virus serotypes identification, if performed routinely, may help to predict and prevent further DHF epidemics based on the exposure of the different serotypes during different periods that lead to the intensification of disease severity as a consequence of antibody-dependent enhancement (ADE)
Making Atomic-Level Magnetism Tunable with Light at Room Temperature
The capacity to manipulate magnetization in two-dimensional dilute magnetic
semiconductors (2D-DMSs) using light, specifically in magnetically doped
transition metal dichalcogenide (TMD) monolayers (M-doped TX2, where M = V, Fe,
Cr; T = W, Mo; X = S, Se, Te), may lead to innovative applications in
spintronics, spin-caloritronics, valleytronics, and quantum computation. This
Perspective paper explores the mediation of magnetization by light under
ambient conditions in 2D-TMD DMSs and heterostructures. By combining magneto-LC
resonance (MLCR) experiments with density functional theory (DFT) calculations,
we show that the magnetization can be enhanced using light in V-doped TMD
monolayers (e.g., V-WS2, V-WSe2, V-MoS2). This phenomenon is attributed to
excess holes in the conduction and valence bands, as well as carriers trapped
in magnetic doping states, which together mediate the magnetization of the
semiconducting layer. In 2D-TMD heterostructures such as VSe2/WS2 and
VSe2/MoS2, we demonstrate the significance of proximity, charge-transfer, and
confinement effects in amplifying light-mediated magnetism. This effect is
attributed to photon absorption at the TMD layer (e.g., WS2, MoS2) that
generates electron-hole pairs mediating the magnetization of the
heterostructure. These findings will encourage further research in the field of
2D magnetism and establish a novel direction for designing 2D-TMDs and
heterostructures with optically tunable magnetic functionalities, paving the
way for next-generation magneto-optic nanodevices
Regulation of SOX11 expression through CCND1 and STAT3 in mantle cell lymphoma
The neural transcription factor SOX11 is usually highly expressed in typical mantle cell lymphoma (MCL), but it is absent in the more indolent form of MCL. Despite being an important diagnostic marker for this hard-to-treat malignancy, the mechanisms of aberrant SOX11 expression are largely unknown. Herein, we describe 2 modes of SOX11 regulation by the cell-cycle regulator cyclin D1 (CCND1) and the signal transducer and activator of transcription 3 (STAT3). We found that ectopic expression of CCND1 in multiple human MCL cell lines resulted in increased SOX11 transcription, which correlated with increased acetylated histones H3K9 and H3K14 (H3K9/14Ac). Increased H3K9/14Ac and SOX11 expression was also observed after histone deacetylase 1 (HDAC1) or HDAC2 was depleted by RNA interference or inhibited by the HDAC inhibitor vorinostat. Mechanistically, we showed that CCND1 interacted with and sequestered HDAC1 and HDAC2 from the SOX11 locus, leading to SOX11 upregulation. Interestingly, our data revealed a potential inverse relationship between phosphorylated Y705 STAT3 and SOX11 expression in MCL cell lines, primary tumors, and patient-derived xenografts. Functionally, inactivation of STAT3 by inhibiting the upstream Janus kinase (JAK) 1 or JAK2 or by STAT3 knockdown was found to increase SOX11 expression, whereas interleukin-21 (IL-21)âinduced STAT3 activation or overexpression of the constitutively active form of STAT3 decreased SOX11 expression. In addition, targeting SOX11 directly by RNA interference or indirectly by IL-21 treatment induced toxicity in SOX11^+ MCL cells. Collectively, we demonstrate the involvement of CCND1 and STAT3 in the regulation of SOX11 expression, providing new insights and therapeutic implications in MCL
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