Chemical composition and toxic activity of essential oil of Caryopteris incana against Sitophilus zeamais

During our screening program for new agrochemicals from Chinese medicinal herbs, essential oil of Caryopteris incana aerial parts was found to possess strong insecticidal activities against the maize weevil, Sitophilus zeamais. A total of 37 components of the essential oil were identified by GC and GC/MS. Estragole (24.8%) and linalool (14.0%) are the two main components of the essential oil followed by 1,8-cineol (5.2%) and δ-guaiene (4.1%). The essential oil possesses strong fumigant toxicity against S. zeamais adults with an LC50 value of 10.05 mg/L air. The essential oil of C. incana also showed contact toxicity against S. zeamais adults with an LD50 value of 122.65 μg/adult. The essential oil C. incana may have potential to be developed as a new natural fumigant/insecticide for the control of stored product insects.Key words: Caryopteris incana, Sitophilus zeamais, fumigant, contact toxicity, essential oil composition, estragole, linalool

Impact of organic hydroperoxides on rat testicular tissue and epididymal sperm

Organic hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide have been implicated to cause oxidative stress leading to damage in membrane lipids, proteins, carbohydrates and DNA. This study was aimed to develop an in vivo animal model. The effects of  hydroperoxides on testicular tissue and epididymal sperm were investigated. Male Wistar rats aged 10 - 12 weeks were randomly placed in groups and received standard rat chow and water ad libitum. Animals were injected intraperitoneally with saline (0.5 ml), t-butyl hydroperoxide (5, 10, 20 and 40 ìM; 0.5 ml) or cumene hydroperoxide cHP (2.5, 5, 10 and 20 ìM; 0.5 ml) over a 60 day period. It was found that cumenehydroperoxide cHP (10 and 20 ìM) and t-butyl hydroperoxide tbHP (20 and 40 ìM) led to significantly lower epididymal sperm concentrations and motility. Superoxide dismutase and glutathione activities were also higher with an accompanying increase in lipid peroxidation in both testicular tissue and epididymal sperm. It can be concluded that in vivo intraperitoneal administration of organic hydroperoxides negatively affect the male reproductive system. We have therefore successfully createdan animal model to test the adverse effects of oxidative stress on male reproductive parameters, thereby, enabling us to study possible in vivo treatments

Computation Energy Efficiency Maximization for Intelligent Reflective Surface-Aided Wireless Powered Mobile Edge Computing

A wide variety of Mobile Devices (MDs) are adopted in Internet of Things (IoT) environments, resulting in a dramatic increase in the volume of task data and greenhouse gas emissions. However, due to the limited battery power and computing resources of MD, it is critical to process more data with less energy. This paper studies the Wireless Power Transfer-based Mobile Edge Computing (WPT-MEC) network system assisted by Intelligent Reflective Surface (IRS) to enhance communication performance while improving the battery life of MD. In order to maximize the Computation Energy Efficiency (CEE) of the system and reduce the carbon footprint of the MEC server, we jointly optimize the CPU frequencies of MDs and MEC server, the transmit power of Power Beacon (PB), the processing time of MEC server, the offloading time and the energy harvesting time of MDs, the local processing time and the offloading power of MD and the phase shift coefficient matrix of Intelligent Reflecting Surface (IRS). Moreover, we transform this joint optimization problem into a fractional programming problem. We then propose the Dinkelbach Iterative Algorithm with Gradient Updates (DIA-GU) to solve this problem effectively. With the help of convex optimization theory, we can obtain closed-form solutions, revealing the correlation between different variables. Compared to other algorithms, the DIA-GU algorithm not only exhibits superior performance in enhancing the system's CEE but also demonstrates significant reductions in carbon emissions

Effects of hydrogen bond and solvent polarity on the C=O strectching of bis(2-thienyl)ketone in solution

The optimized structural parameters, the absorption and the resonance Raman spectra have been investigated for the bis(2-thienyl)ketone in gas phase, in cyclohexane, methanol, and acetonitrile solvents by means of time dependent density functional theory calculations, the solvent electronic polarization effect on the solvation shift is examined and in well accordance with the calculation. The effect of increasing the polarity of the solvent is well represented by the polarizable continuum model, both for the absorption spectra and resonance Raman intensities. The Raman spectra of the C=O stretching mode, which is sensitive to the intermolecular interaction for bis(2-thienyl)ketone dissolved in solvents, were systematically studied. It was found that the hydrogen bond effect plays an important role in reducing the carbonyl stretching wavenumbers. The results of Raman shifts were interpreted through the dilution effect, solvation effects, and hydrogen bond-forming effects. Furthermore, the excitation profiles of several important Raman bands of bis(2-thienyl)ketone molecule in different solvents have been critically analyzed. The solvent effects on structural and symmetry properties of the molecule in S2 electronic state as well as the short-time photo relaxation dynamics have been discussed.published_or_final_versio

Microstructures and resistivity of cuprate/manganite bilayer deposited on SrTiO3 substrate

Thin Yba[SUB2]Cu[SUB3]O[SUB7-δ/La[SUB0.67]Ca[SUB0.33]MnO[SUB3] (YBCO/LCMO) films were grown on SrTiO[SUB3](STO)substrates by magnetron sputtering technique. The microstructures of the bilayers were characterized and a standard four-probe technique was applied to measure the resistivity of the samples. The interdiffusions at the YBCO/LCMO and LCMO/STO interfaces formed two transient layers with the thickness of about 3 and 2 nm, respectively. All the bilayers were well textured along the c axis. At low temperature, the superconductivity can only be observed when the thickness of YBCO is more than 25 nm. When the thickness of YBCO is less than 8 nm, the bilayers show only ferromagnetism. The superconductivity and ferromagnetism perhaps coexist in the bilayer with the YBCO thickness of 12.5 nm. These interesting properties are related to the interaction between spin polarized electrons in the manganites and the cooper pairs in the cuprates. © 2003 American Institute of Physics.published_or_final_versio

Nitisinone Arrests but Does Not Reverse Ochronosis in Alkaptonuric Mice.

Alkaptonuria (AKU) is an ultrarare autosomal recessive disorder resulting from a deficiency of homogentisate 1,2 dioxygenase (HGD), an enzyme involved in the catabolism of phenylalanine and tyrosine. Loss of HGD function prevents metabolism of homogentisic acid (HGA), leading to increased levels of plasma HGA and urinary excretion. Excess HGA becomes deposited in collagenous tissues and subsequently undergoes polymerisation, principally in the cartilages of loaded joints, in a process known as ochronosis. This results in an early-onset, devastating osteoarthropathy for which there is currently no effective treatment. We recently described the natural history of ochronosis in a murine model of AKU, demonstrating that deposition of ochronotic pigment begins very early in life and accumulates with age. Using this model, we were able to show that lifetime treatment with nitisinone, a potential therapy for AKU, was able to completely prevent deposition of ochronotic pigment. However, although nitisinone has been shown to inhibit ochronotic deposition, whether it can also facilitate removal of existing pigment has not yet been examined. We describe here that midlife administration of nitisinone to AKU mice arrests further deposition of ochronotic pigment in the tibiofemoral joint, but does not result in the clearance of existing pigment. We also demonstrate the dose-dependent response of plasma HGA to nitisinone, highlighting its efficacy for personalised medicine, where dosage can be tailored to the individual AKU patient

Economic factors influencing zoonotic disease dynamics: demand for poultry meat and seasonal transmission of avian influenza in Vietnam

While climate is often presented as a key factor influencing the seasonality of diseases, the importance of anthropogenic factors is less commonly evaluated. Using a combination of methods-wavelet analysis, economic analysis, statistical and disease transmission modelling-we aimed to explore the influence of climatic and economic factors on the seasonality of H5N1 Highly Pathogenic Avian Influenza in the domestic poultry population of Vietnam. We found that while climatic variables are associated with seasonal variation in the incidence of avian influenza outbreaks in the North of the country, this is not the case in the Centre and the South. In contrast, temporal patterns of H5N1 incidence are similar across these 3 regions: periods of high H5N1 incidence coincide with Lunar New Year festival, occurring in January-February, in the 3 climatic regions for 5 out of the 8 study years. Yet, daily poultry meat consumption drastically increases during Lunar New Year festival throughout the country. To meet this rise in demand, poultry production and trade are expected to peak around the festival period, promoting viral spread, which we demonstrated using a stochastic disease transmission model. This study illustrates the way in which economic factors may influence the dynamics of livestock pathogens

Urban green infrastructure and ecosystem services in sub-Saharan Africa

Africa is urbanizing at an astonishing rate. To meet many of the Sustainable Development Goals there will be a requirement for cities in sub-Saharan Africa to plan for, and manage, the rapid rise in the urban population. Green infrastructure has the potential to provide multiple ecosystem services to benefit the urban population. The general objective of this review is to consolidate research undertaken on urban green infrastructure and the associated ecosystem services in sub-Saharan African cities. The 68 reviewed papers spanned 20 countries and included 74 urban areas. However, only 38% of sub-Saharan countries had any research carried out in them. The most represented ecosystem services were regulating and provisioning, with supporting services getting the least attention. Overall there was a lack of in-depth studies on all ecosystem services, especially supporting and cultural services. Seven overarching categories of barriers and challenges to the sustainable delivery of ecosystem services emerged from the reviewed papers, namely: (i) socio-cultural values, traditions and perceptions; (ii) lack of capacity; (iii) governance, urban planning and social inequality; (iv) lack of data and/or case studies; (v) ecosystem disservices; (vi) spatial trade-offs and conflicts; (vii) climate change. These barriers we identified will need to be addressed if the future, long-term sustainable provision of ecosystem services in sub-Saharan African cities is to be assured

Spin pumping in magnetic trilayer structures with an MgO barrier

We present a study of the interaction mechanisms in magnetic trilayer structures with an MgO barrier grown by molecular beam epitaxy. The interlayer exchange coupling, A ex, is determined using SQUID magnetometry and ferromagnetic resonance (FMR), displaying an unexpected oscillatory behaviour as the thickness, t MgO, is increased from 1 to 4 nm. Transmission electron microscopy confirms the continuity and quality of the tunnelling barrier, eliminating the prospect of exchange arising from direct contact between the two ferromagnetic layers. The Gilbert damping is found to be almost independent of the MgO thickness, suggesting the suppression of spin pumping. The element-specific technique of X-ray detected FMR reveals a small dynamic exchange interaction, acting in concert with the static interaction to induce coupled precession across the multilayer stack. These results highlight the potential of spin pumping and spin transfer torque for device applications in magnetic tunnel junctions relying on commonly used MgO barriers