2,928 research outputs found

    Effects of red and blue light ratio on the morphological traits and flower sex expression in Cucurbita moschata Duch.

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    Squash (Cucurbita moschata Duch.) is an important fruit vegetable that can be long-term transport and storage. Light-emitting diodes (LEDs) are commercially used light sources applied to improve the producing of leaf vegetables in plant factory. However, the influences of LEDs on the plant growth and flower development of fruit vegetables remain unknown. In this study, five effective light quality treatments, including white light, a 10:8 ratio of blue (B) to red (R) light, a 10:4 mixture of blue/red light, red light, and blue light, were used for growing squash and inducing female flowers to maximize production. Our results show that varying light quality influence morphological traits and flower appearance. Both blue and red light improved the development of first and second internodes and induced larger leaves and petiole lengths, whereas 10:4 mixture caused shorter plant heights and decreased internode and petiole lengths. Although 10:8 mixture treatment reduced chlorophyll content, this spectral regime increased leaf number and influenced flower sex development, inducing more female flowers and more fruits. Light quality manipulation thus beneficially influences the growth and flower sex proportion in squash plants. Squash plants under 10:8 mixture treatment exhibited increase in yield, and can be used as a supplementary light treatment in plant factory

    Using Hybrid Angle/Distance Information for Distributed Topology Control in Vehicular Sensor Networks

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    In a vehicular sensor network (VSN), the key design issue is how to organize vehicles effectively, such that the local network topology can be stabilized quickly. In this work, each vehicle with on-board sensors can be considered as a local controller associated with a group of communication members. In order to balance the load among the nodes and govern the local topology change, a group formation scheme using localized criteria is implemented. The proposed distributed topology control method focuses on reducing the rate of group member change and avoiding the unnecessary information exchange. Two major phases are sequentially applied to choose the group members of each vehicle using hybrid angle/distance information. The operation of Phase I is based on the concept of the cone-based method, which can select the desired vehicles quickly. Afterwards, the proposed time-slot method is further applied to stabilize the network topology. Given the network structure in Phase I, a routing scheme is presented in Phase II. The network behaviors are explored through simulation and analysis in a variety of scenarios. The results show that the proposed mechanism is a scalable and effective control framework for VSNs

    Remaining As A Leader or Not? Technology Spillover Answers

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    Much has been discussed about the advantages and disadvantages of being a first mover. However, discussion regarding the incentives encouraging a firm to remain as leader is absent in most studies. This paper aims to fill this gap and provide theoretical and empirical evidences vis-Ă -vis the incentives of remaining as a leader, by comparing profits between leader and follower when taking technology spillover and technological efficiency into consideration. The findings show that in regard to effective technological efficiency: (i) under the condition of a weak (strong) technology spillover, retaining the position of leader firm is (not) a dominant strategy because of higher (lower) profits than a follower; (ii) the half-shared technology spillover leads to an equal profit between firms, and implies a critical time of action for the leader firm to break the evenly-matched status by reconsidering first mover advantages; (iii) an empirical study on a data set of 352 high-tech and non-high-tech SMEs in manufacturing industry from 1999 until 2006 lends strong support to these results and may also provide useful clues for technology managers or practitioners to make better policies to benefit their market competitiveness

    Nonlinear photoacoustic microscopy via a loss modulation technique: from detection to imaging

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    In order to achieve high-resolution deep-tissue imaging, multi-photon fluorescence microscopy and photoacoustic tomography had been proposed in the past two decades. However, combining the advantages of these two imaging systems to achieve optical-spatial resolution with an ultrasonic-penetration depth is still a field with challenges. In this paper, we investigate the detection of the two-photon photoacoustic ultrasound, and first demonstrate background-free two-photon photoacoustic imaging in a phantom sample. To generate the background-free two-photon photoacoustic signals, we used a high-repetition rate femtosecond laser to induce narrowband excitation. Combining a loss modulation technique, we successfully created a beating on the light intensity, which not only provides pure sinusoidal modulation, but also ensures the spectrum sensitivity and frequency selectivity. By using the lock-in detection, the power dependency experiment validates our methodology to frequency-select the source of the nonlinearity. This ensures our capability of measuring the background-free two-photon photoacoustic waves by detecting the 2nd order beating signal directly. Furthermore, by mixing the nanoparticles and fluorescence dyes as contrast agents, the two-photon photoacoustic signal was found to be enhanced and detected. In the end, we demonstrate subsurface two-photon photoacoustic bio-imaging based on the optical scanning mechanism inside phantom samples

    THE EFFECTS OF FUNGAL MEDIUM ON HATCHING RATE OF BITING MIDGE

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    The little black mosquitos, Forcipomyia taiwana, bite human and become one of the most annoying pests in Taiwan. Recently, the population of F. taiwana increases and invades urban and countryside. In order to effectively prevent the harassment of F. taiwana, develop control strategy is urgent and necessary. Our study found that the fungal medium influenced the length and width of the F. taiwana eggs. It also significantly decreased the hatching rate of F. taiwana. Besides, this artificial diet was more non-toxic and environment-friendly than general chemical pesticides. Thus, this study provided critical information to develop potentially useful bait of F. taiwana in the future

    Refrigerant- Lubricant Mixture Properties Influencing Bubble Dynamic Parameters and Heat Transfer Coefficient in Nucleate Pool Boiling

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    We have been successfully developed a model regarding lubricant effect on individual processes of bubble nucleation, growth and departure period for nucleate pool boiling heat transfer. In this study, three type POE refrigeration lubricants with different refrigerant miscibility (POEA/POEB/POEC), two viscosity grades (ISO68 & 170), three kind of refrigerants (R-134a/R-1234ze/R-134yf), and three different saturated temperatures (10℃/0℃/10℃) are taken into calculation under different heat flux ranging from 10 KW/m2 to 80 KW/m2. Based on this model, a knowledge of chemical structures and physical properties of lubricant and refrigerant is sufficient to get bubble dynamic parameters and predict the boiling performance near metal surface. According to calculating results, several key factors play an important role in pool boiling heat transfer and show drastic influence on bubble parameters and HTC, such as refrigerant type, saturated temperature, heat flux and lubricant concentration. Regarding lubricant chemical structure effect on heat transfer performance, it will be direct related to OCR and following influence on HTC in real evaporator environment. But if keeping same lubricant concentration, different results will appear. Various lubricant structures may provide different volume size, adsorption energy on metal surface and interaction force between refrigerant and lubricant, but these factors sometimes offset each other and lead to only a slight difference in bubble size, contact angle, surface coverage concentration, and HTC. The calculation indicates that the presence of lubricant imposes a negative effect on HTC during waiting period of bubble formation and departure period, but a positive effect on HTC may prevail in bubble growth period. Such two effects compete during the boiling process and could lead increase or impair heat transfer performance at a low lubricant concentration

    Plasma levels in sepsis patients of annexin A1, lipoxin A4, macrophage inflammatory protein-3a, and neutrophil gelatinase-associated lipocalin

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    AbstractBackgroundThe relationship between the various cytokine responses that occur during sepsis remains controversial. Emerging evidence indicates that the proinflammatory and anti-inflammatory responses are regulated simultaneously from the beginning of sepsis. However, the roles of the novel anti-inflammatory mediators annexin (Anx)A1 and lipoxin (LX)A4 and the proinflammatory cytokines neutrophil gelatinase-associated lipocalin (NGAL) and macrophage inflammatory protein (MIP)-3a have been studied.MethodsIn this study, the plasma levels of AnxA1, LXA4, NGAL, MIP-3a, interleukin (IL)-8 and IL-6 in patients with sepsis were determined on admission to the intensive care unit. The patients were classified into survivors and non-survivors based on their outcome on day 28.ResultsAnxA1 and LXA4 levels were decreased in sepsis patients compared with control patients, whereas the levels of the proinflammatory cytokines MIP-3a, NGAL, IL-8, and IL-6 were elevated. Furthermore, a significantly higher level of MIP-3a was detected in nonsurviving patients compared with surviving patients (p < 0.05), whereas there were no significant differences between these two groups for the levels of the other mediators. Correlation analysis demonstrated that only NGAL level was closely correlated with the level of IL-6. Univariate analysis indicated that the levels of MIP-3a and IL-8 were independent factors associated with patient survival, but this was not confirmed by the multivariate analysis.ConclusionAnxA1 and LXA4 plasma levels were found to be decreased in sepsis patients, whereas the levels of MIP-3a and NGAL were found to be elevated. This warrants further study in order to determine the clinical implications of these changes
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