Panax vietnamensis, or Vietnamese ginseng (VG), an endemic Panax species in Vietnam, possesses a unique saponin profile and interesting biological activities. This plant is presently in danger of ...extinction due to over-exploitation, resulting in many preservation efforts towards the geographical acclimatization of VG. Yet, no information on the saponin content of the acclimatized VG, an important quality indicator, is available. Here, we analyzed the saponin content in the underground parts of two- to five-year-old VG plants acclimatized to Lam Dong province. Nine characteristic saponins, including notoginsenoside-R1, ginsenoside-Rg1, -Rb1, -Rd, majonoside-R1, -R2 vina-ginsenoside-R2, -R11, and pseudoginsenoside-RT4, were simultaneously determined by HPLC coupled with UV and with a charged aerosol detector (CAD). Analyzing the results illustrated that the detection of characteristic ocotillol-type saponins in VG by CAD presented a superior capacity compared with that of UV, thus implying a preferential choice of CAD for the analysis of VG. The quantitative results indicating the saponin content in the underground parts of VG showed an increasing tendency from two to five years old, with the root and the rhizome exhibiting different saponin accumulation patterns. This is the first study that reveals the preliminary success of VG acclimatization and thereby encourages the continuing efforts to develop this valuable saponin-rich plant.
This paper compares effectiveness of the different approaches of computing the tilt angle of the horizontal gradient amplitude and tilt angle of the analytic signal amplitude such as use of direct ...expression and frequency domain technique (also called k - function) in terms of their accuracy on the detection of the edges of magnetic and gravity sources. These approaches were performed on both synthetic magnetic and gravity data where the frequency domain technique shows improvements in delineation of the actual edges of the sources compared to the direct expression. Additionally, real magnetic data from Zhurihe (Northeast China), and real gravity data from Tuan Giao (Northwest Vietnam) was considered and the obtained results from applying the different approaches were compared with known geological structures. The results show that the boundaries detected from the use of the frequency domain technique are in accord with the known geological structures.
•We examine the epitaxial PZT thin films with various thicknesses and compositions.•Cantilevers consist of all-oxide piezoelectric stacks and silicon devices.•Reduction in interfacial and clamping ...effects with increasing film thickness.•Transverse piezoelectric coefficient and mass-sensitivity peak on the tetragonal side.•Epitaxial PZT thin film enhances the mass-sensitivity.
The transverse piezoelectric coefficient e31,f and mass-sensitivity were measured on piezoelectric cantilevers based on epitaxial PZT thin-films with film-thicknesses ranging from 100 to 2000nm. The highest values of e31,f and mass-sensitivity were observed at a film thickness of 500–750nm, while the observed remnant polarization Pr and longitudinal piezoelectric coefficient d33,f values become saturated with a film thickness of 750–1000nm. To obtain high performance by making use of its optimal film thickness, PZT thin films with various Zr/Ti ratios from 20/80 to 80/20 were studied. The experimental results indicated that the ferroelectric property reached a highest remnant polarization Pr at a Zr/Ti ratio of 20/80, while the longitudinal piezoelectric coefficient d33,f increased with increasing Zr content and reaches a maximum at a Zr/Ti ratio of 52/48. The findings suggest that the optimal composition for mass-sensitivity and transverse piezoelectric coefficient e31,f was shifted to the tetragonal part of the phase diagram with the Zr/Ti ratios of 45/55 and 40/60, respectively.
Two threatened dipterocarp species,
Dipterocarpus costatus
and
Dipterocarpus alatus
are well-known endangered species in lowland forests of southeastern Vietnam, primarily from habitat loss and ...over-exploitation of their wood. To develop conservation strategies for these species, we analyzed 242 samples using nine microsatellite markers to determine the genetic variability within and among five populations of
D. alatus
and three of
D. costatus
, representing the natural range of dipterocarps in Southeast Vietnam. Results indicated low levels of genetic variability within populations with an average gene diversity of 0.223 for
D. alatus
and 0.152 for
D. costatus
. Results of bottleneck tests indicated a reduction in population size of both species (
P
> 0.05). Genetic differentiation among populations was high (
F
ST
= 0.347 for
D. costatus
and 0.274 for
D. alatus
), indicating limited gene flow (
N
m
= 0.662 for
D. costatus
and 0.47 for
D. alatus
) and isolated populations related to geographical distances. Analysis of molecular variance showed high genetic variation within populations (72.92% for
D. alatus
and 60.81% for
D. costatus
) compared to among populations. Bayesian analysis and UPGMA tree also indicated the two optimal genetic clusters related to geographical distances. These results will provide a platform for the conservation, management and restoration of these species.
Main conclusion
Moderate levels of genetic diversity and differentiation of Anisoptera costata were determined. A population divergence occurred during Younger Dryas. The anthropogenic disturbance ...had significantly affected the genetic diversity of the species in low tropical forests
.
Anisoptera costata
Korth, an endangered species, is mainly distributed in the lowland tropical forests of the Southeast region in Vietnam, which has not been explored for genetic diversity and demographic history. In this study, eight polymorphic microsatellite markers were used to analyze 232 wild trees of
A. costata
at nine different populations, representing the natural distribution range of the species in Vietnam. Genetic diversity within the populations was determined with mean values of 0.284 and 0.327 observed and expected heterozygosity, respectively, while genetic differentiation among populations was found with Weir and Cockerham index of 0.12 and Hedrick index of 1.38. These results indicated that habitat fragmentation by the anthropogenic disturbance may be the major factor for the low heterozygosity values and affected the number of alleles in all the targeted populations of
A. costata
in lowland tropical forests. Populations in the Central Southeast area had a higher level of genetic diversity than the populations in the Coastal and Western Southeast areas. The analysis of molecular variance showed that high genetic variation existed within populations (86.15%) compared to the variation among populations. A reduction in the population size of
A. costata
was determined by BOTTLENECK. Different clustering methods (Bayesian analysis, the neighbor-joining tree, and principal coordinate analysis) suggested optimal genetic clusters related to gene flow among different areas. Approximate Bayesian computation suggested that population divergence occurred during Younger Dryas. We also discussed the measures for species conservation based on these results.
Voicify Your UI Vu, Minh Duc; Wang, Han; Li, Zhuang ...
Proceedings of ACM on interactive, mobile, wearable and ubiquitous technologies,
03/2023, Letnik:
7, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Nowadays, voice assistants help users complete tasks on the smartphone with voice commands, replacing traditional touchscreen interactions when such interactions are inhibited. However, the usability ...of those tools remains moderate due to the problems in understanding rich language variations in human commands, along with efficiency and comprehensibility issues. Therefore, we introduce Voicify, an Android virtual assistant that allows users to interact with on-screen elements in mobile apps through voice commands. Using a novel deep learning command parser, Voicify interprets human verbal input and performs matching with UI elements. In addition, the tool can directly open a specific feature from installed applications by fetching application code information to explore the set of in-app components. Our command parser achieved 90% accuracy on the human command dataset. Furthermore, the direct feature invocation module achieves better feature coverage in comparison to Google Assistant. The user study demonstrates the usefulness of Voicify in real-world scenarios.
We present a new planning model for freight consolidation carriers, one that links strategic, resource acquisition, and allocation decisions with tactical, service network design-related decisions. ...Specifically, such as service network design models that recognize resource constraints, the model selects services and routes both commodities and the resources needed to support the services that transport them. In addition, the model recognizes that resources can be grouped into types that differ from one another with respect to capabilities, e.g., speeds, capacities, scheduling rules, etc. Ultimately, along with recognizing resource constraints, the model also makes strategic decisions such as how many resources of each type should be acquired, to what terminal new resources should be assigned, and which existing terminal-based resources should be reassigned. As such, the model can be used from a strategic planning, resource acquisition, mixing, and allocation perspective as it provides an estimate of the impact of such decisions on transportation costs. We extend a matheuristic for a service network design problem with a fixed set (both in number and allocation) of resources of a single type to one that can also make these acquisition and allocation decisions for multiple types of resource. Then, with an extensive computational study, we demonstrate the efficacy of the matheuristic and benchmark its performance against both a leading commercial solver and a column generation-based heuristic. Finally, we perform an extensive computational study to understand how the resource-related and service network design-related components of the model interact, including how freight volumes and cost structures impact how many resources should beacquired.
The AC battery utilizing second-life time batteries has gained great interest currently with the advantages of both power solutions and economic benefits. In this system, the power converters play a ...crucial role in the stable and effective operation of the system. This paper focused on the AC/DC stage with the chosen topology being the interleaved full bridge (IFB) converter due to its flexibility and the ability to increase the power rate of the system. For the sake of high-performance operation, various pulse width modulation (PWM) methods for this converter are analyzed. First, based on the theory of the traditional PWM methods for a full bridge inverter in combination with the interleaved technique, this paper proposed three interleaved PWM methods for the IFB converter. Secondly, the proposed methods are theoretically compared in terms of the output current, common-mode voltage, and power losses. Finally, the evaluation is carried out by both the simulation and the experimental prototype, in which the results are in good agreement with the theoretical analysis.
Shrimp aquaculture is the biggest source of export income in Vietnam. However, the development of the shrimp poses a serious threat to coastal mangroves by converting coastal mangroves into shrimp ...farms. Much effort has been made to replant mangroves and reduce the impacts of shrimp farming on the environment, and maintaining mangrove coverage at 30–50% of total farm area has provided the highest benefits in the integrated mangrove shrimp model. In this study, we re-examine the benefits of forest cover on the survival and yield of tiger shrimp (
Penaeus monodon
) in the integrated mangrove shrimp farming systems in Ca Mau province, Vietnam. The study found positive linear correlations of log transformed survival and yield of tiger shrimp with forest cover of the forms: Ln (survival) = − 1.39 + 0.038 × forest coverage (
r
2
= 0.22;
p
value = 0.0007); Ln (yield) = 3.55 + 0.026 × forest coverage (
r
2
= 0.16;
p
value = 0.004). The households with high forest cover (i.e., > 45%) also had 1.07 ± 0.29 and 1.39 ± 0.36 (CI 95%,
p
value = 0.000) kg ha
−1
higher yield per night harvest than those with medium and low forest cover, respectively. As a result, households with high forest cover have higher benefits than those with lower forest cover. Our findings together with previous published studies lead to the recommendation that farmers maintain mangroves in farming systems for better economic and environmental benefits.
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