Floating of the lobes of mosquito (Aedes togoi) larva for respiration

Mosquito (Aedes togoi) larva has to float its siphon on the water surface to breathe air. To elucidate the floating mechanism of the siphon, morphological structures, especially the flap-like lobes and spiracle of the siphon, were observed. Wettability and dynamic behavior of the lobes on the water surface were also experimentally examined. The lobes formed a hollow cone shape under water and expanded on the water surface. The spiracle was located at the base of the cone. The lobes exhibited hydrophobic wettability. During floating process, the lobes were spread into a triangular shape in apical view, and the spiracle was exposed to air. When they were submerged in water, the lobes were folded into a cone shape to seal the spiracle and protect it from water penetration. These dynamic processes occurred at the water surface. In this study, the floating mechanism of the lobes for respiration was described based on the cross-sectional morphology of the lobes with the pressure induced by surface tension and the hydrostatic pressure proportional to depth. This study would be helpful in elucidating the behavior of mosquito larvae near the water surface and may facilitate the formulation of methods to control mosquito larvae.1122Ysciescopu

Transformation completeness properties of SVPC transformation sets

AbstractA set T of permutations of a finite set D is said to be transformation complete if the orbits of 〈T〉, the group generated by T, acting on F(D), the power set of D, are exactly the set of subsets of D having the same cardinality, where the orbit of xϵF(D) is {α(x)|αϵ〈T〉}. This paper studies the transformation completeness properties of suppressed variable permutation and complementation (SVPC) transformations which act on Boolean variables with domain being D = {0, 1}n. An SVPC transformation with r control variables is an identity on the n-cube except on an (n − r)-subcube where the acting is like a variable permutation and complementation (VPC) transformation on n − r variables, 0≤r<n. Let Pnr be the set of all SVPC transformations on n variables with r control variables. It is shown that Pnr is transformation complete for n>r≥1. In particular, it is shown that S2n = 〈Pnn−1〉 = 〈Pnn−2〉 ⊃ 〈Pnn−3〉 = 〈Pnn−4〉 = ⋯ = 〈Pn1〉 = A2n ⊃ 〈Pn0〉, where S2n and A2n are the symmetric group and alternating group of degree 2n, respectively. Pn0, i.e., the VPC transformation group on n variables, is not transformation complete, however. Thus, one control variable is necessary and sufficient to make Pnr transformation complete

Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis

Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.112Ysciescopu

Systematic review of the effects of bisphosphonates on bone density and fracture incidence in childhood acute lymphoblastic leukaemia

Skeletal fragility is a common complication of childhood acute lymphoblastic leukaemia (ALL) but the impact of bisphosphonate therapy on bone mass and fracture is unclear. We aim to conduct a systematic review to evaluate the effects of bisphosphonates on bone mineral density (BMD) and fracture incidence in children with ALL. EMBASE, Medline and the Cochrane Library were thoroughly searched by two researchers. Inclusion criteria was any child under the age of 18 years with a diagnosis of ALL, who had received any bisphosphonate treatment and had serial measurements of bone density performed thereafter. All primary research studies of any study design, excluding case reports, were included. Ten full text papers were identified with two exclusively meeting the inclusion criteria. Both studies administered bisphosphonates to children receiving maintenance chemotherapy for varying durations. Bone density was assessed at regular intervals by dual x-ray absorptiometry (DXA). The majority of participants had an improvement in bone density at the end of each study. However, no size adjustment of DXA data was performed. Limited information on fracture occurrence was provided by one study but did not include routine screening for vertebral fractures. This systematic review identified that there is insufficient evidence to support routine use of prophylactic bisphosphonate therapy in childhood ALL for prevention of fracture and improvement of bone mass. Future well-designed clinical trials in those at highest risk of fractures in ALL are now needed

A Study Of Virtuous Cycle Of Service Participation On Crowdsourcing Platforms

Competition has undoubtedly increased substantially over the last decade for several reasons. The Internet has been far and away the largest contributor to the rise in competitive markets due to establishing an online business has lower operating costs and greater flexibility. Companies must have internet business ideas to survive to stay competitive in today’s markets. Crowdsourcing is a phenomenon receiving highly attention both inside and outside of academia. With the rapid development of Web2.0 and social media, an emerging business model like a raging fire impacts on the market: a crowdsourcing platform. Crowdsourcing platforms provide a good environment to fulfill people’s needs and seize value from providing products and services. It is important to understand what drives people to deliver and capture values from a crowdsourcing platform. The purpose of this paper is to explore how service participation works on successful crowdsourcing platforms in their cycles. We focus on why do participants (both sides of supply and demand) are willing to join into the platform to provide services and request services, finding out their virtuous cycles on the platforms in different applications. This study is the first of its kind to explore how service participation works on successful crowdsourcing platforms in their cycles. We will use a qualitative multiple case study, which facilitated an exploration of the phenomenon in an area that has received little theoretical development and allowed us to study the cycle of service participation on crowdsourcing platform in a real-life context. The results may reveal us some significant driving factors on why people are willing to provide and request services on crowdsourcing platforms and what important strategies should be taken while running a crowdsourcing platform. This not only gives us a more broaden view of crowdsourcing and platform operating, but also provides companies, which use crowdsourcing platform to run their business, a more realistic decision making references

The in vitro effects of dehydroepiandrosterone on human osteoarthritic chondrocytes

AbstractObjective: To investigate the in vitro effects of dehydroepiandrosterone (DHEA) on human osteoarthritic chondrocytes.Design: Chondrocytes isolated from human osteoarthritic knee cartilage were three-dimensionally cultured in alginate beads, except for cell proliferation experiment. Cells were treated with DHEA in the presence or absence of IL-1β. The effects on chondrocytes were analyzed using a 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay (for chondrocyte proliferation), a dimethylmethylene blue (DMB) assay (for glycosaminoglycan (GAG) synthesis), and an indole assay (for DNA amount). Gene expressions of type I and II collagen, metalloproteinase-1 and -3 (MMP-1 and -3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) as well as the IL-1β-induced gene expressions of MMP-1 and -3 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The protein synthesis of MMP-1 and -3 and TIMP-1 was determined by Western blotting.Results: The treatment of chondrocytes with DHEA did not affect chondrocyte proliferation or GAG synthesis up to 100μM of concentration. The gene expression of type II collagen increased in a dose-dependent manner, while that of type I decreased. DHEA suppressed the expression of MMP-1 significantly at concentrations exceeding 50μM. The gene expression of MMP-3 was also suppressed, but this was without statistical significance. The expression of TIMP-1 was significantly increased by DHEA at concentrations exceeding 10μM. The effects of DHEA on the gene expressions of MMP-1 and -3 were more prominent in the presence of IL-1β, in which DHEA suppressed not only MMP-1, but also MMP-3 at the lower concentrations, 10 and 50μM, respectively. Western blotting results were in agreement with RT-PCR, which indicates that DHEA acts at the gene transcription level.Conclusions: Our study demonstrates that DHEA has no toxic effect on chondrocytes up to 100μM of concentration and has an ability to modulate the imbalance between MMPs and TIMP-1 during OA at the transcription level, which suggest that it has a protective role against articular cartilage loss

Antioxidant activity and contents of total phenolic compounds and anthocyanins according to grain colour in several varieties of Sorghum bicolor (L.) Moench

Sorghum bicolor (L.) Moench contains various phenolic compounds such as anthocyanin. Eleven sorghum accessions were classified into five groups by grain colour and their antioxidant activities were measured as well as the contents of total phenolic compounds (TPC) and anthocyanins in sorghum grains. The grain colour was related to TPC content, but not to monomelic anthocyanin content. Moreover, the overall patterns of antioxidant activity levels in 2,2-Diphenyl-1-picrylhydrazyl (DPPH) or 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay were similar to those of the TPC content. Correlations between TPC and anthocyanin contents were statistically significant and positive (P < 0.05). TPC content showed also a strong positive correlation to DPPH and ABTS antioxidant activities. The results provide the basic data for breeding of sorghum varieties containing large amounts of antioxidants

The use of small stents to delay surgical intervention in very young children with critical congenital heart disease

Introduction: Surgery in very young children with critical obstructive congenital heart disease has a high morbidity and mortality. The aim of this study was to determine whether the use of small stents is feasible and if it could delay surgery. Materials and methods: Nineteen children were included in a retrospective review spanning 7 years. Patients were included in circumstances where surgery needed to be delayed and the use of a small stent could alleviate the underlying obstruction. Results: All attempts at stenting were successful (100%). Indications were diverse and included: aortic obstruction (n=9), right ventricular outfl ow tract obstruction (n=3), systemic-to-pulmonary artery shunt occlusion (n=5), infradiaphragmatic pulmonary vein obstruction (n=1) and salvage of a discontinuous left pulmonary artery (n=1). Reasons patients were not fi t for surgical intervention included: low weight (n=4), poor general clinical condition (n=12), surgical technical diffi culty (n=2) and unavailability of a critical care bed (n=1). Median age and weight at procedure was 4.6 months (range: 0.1 - 18.3) and 4.5kg (range: 1.7 - 9.5), respectively. Pressure gradients and saturations showed signifi cant improvement post stenting. Periprocedural complications were few (n=3) and there were no fatalities. Last follow-up was at a median of 7.8 months (range: 0.1 -9.0) post initial procedure. Nine cases proceeded to corrective surgery. Surgery was delayed by a median 13.5 months (range: 0.3 - 69.0 months) and weight increased to a median of 10.3kg (p&lt;0.001). Five cases demised at a median of 73 days (range: 1 - 422) post initial stent placement, most at home secondary to unknown causes. Four patients remain in follow-up. One patient was lost to follow-up. Conclusion: The placement of stents in small, ill children is feasible. It immediately relieves the obstruction and improves the general clinical condition. Surgery can be delayed for weeks or months, thus giving the opportunity for somatic growth

Discrete Multitone Modulation for Maximizing Transmission Rate in Step-Index Plastic Optical Fibres

The use of standard 1-mm core-diameter step-index plastic optical fiber (SI-POF) has so far been mainly limited to distances of up to 100 m and bit-rates in the order of 100 Mbit/s. By use of digital signal processing, transmission performance of such optical links can be improved. Among the different technical solutions proposed, a promising one is based on the use of discrete multitone (DMT) modulation, directly applied to intensity-modulated, direct detection (IM/DD) SI-POF links. This paper presents an overview of DMT over SI-POF and demonstrates how DMT can be used to improve transmission rate in such IM/DD systems. The achievable capacity of an SI-POF channel is first analyzed theoretically and then validated by experimental results. Additionally, first experimental demonstrations of a real-time DMT over SI-POF system are presented and discusse

Spin symmetry breaking in bilayer quantum Hall systems

Based on the construction of generalized Halperin wave functions, we predict the possible existence of a large class of broken spin symmetry states in bilayer quantum Hall structures, generalizing the recently suggested canted antiferromgnetic phase to many fractional fillings. We develop the appropriate Chern-Simons theory, and establish explicitly that the low-lying neutral excitation is a Goldstone mode and that the charged excitations are bimerons with continuously tunable (through the canted antiferromagnetic order parameter) electric charge on the individual merons.Comment: 4 page