Phloem Alkaloid Tolerance Allows Feeding on Resistant Lupinus angustifolius by the Aphid Myzus persicae

We examined the hypothesis that the polyphagous green peach aphid (Myzus persicae) shows clone-specific adaptation to the narrow-leafed lupin (Lupinus angustifolius) containing toxic quinolizidine alkaloids. We compared the performance of a lupin-feeding clone of M. persicae from Western Australia to that of nine clones of the same species collected from eastern Australian locations, where narrow-leafed lupins rarely occur. Mean relative growth rate (MRGR) and colonization ability varied among the M. persicae clones on one aphid-susceptible and two aphid-resistant lupin varieties. The performance of the lupin-feeding clone was better than that of all other clones on the resistant narrow-leafed lupin varieties “Tanjil” and “Kalya”, indicating that successful lupin feeding is not a characteristic of the species. Gas chromatography-mass spectrometry analyses (GC-MS) of phloem from the different lupin varieties detected differences in the quantities of two alkaloid compounds identified as 13-OH-lupanine and lupanine. The lupin-feeding M. persicae clone also showed better performance on artificial diet amended with lupanine. The results suggest that the M. persicae clone collected from Western Australia is adapted to feed successfully on narrow-leafed lupin, and that this adaptation may involve improved tolerance of lupanine in its diet.     

黄腐酸和羟丙基-β-环糊精对阿司匹林分解的影响比较

研究了黄腐酸（FA）作为一种的新的络合剂,与羟丙基-β-环糊精络合物（Hp-β-CD）相比,对阿司匹林（ASA）分解的影响。ASA与FA以1：0.5、1：1、1：2（物质的量比）络合,并用冷冻干燥、溶剂蒸发和喷雾干燥三种方法进行干燥。ASA-羟丙基-β-环糊精（1：1）络合物通过喷雾干燥制备,并与最佳FA络合物进行比较。将所有的络合物和ASA放入贴好标签的铝塑小包中密封,在温度为40±2℃、相对湿度为75%±5%的稳定暗箱中存放120d。分别在0、30d、60d、90d和120d分析各样品的水杨酸含量。以物质的量比为1：1进行络合的ASA-FA喷雾干燥络合物中水杨酸含量为4.31%,该络合物在所有不同制备方法的络合物中具有最佳稳定性。然而,1：1的ASA-羟丙基-β-环糊精喷雾干燥络合物中测得水杨酸含量只有2.35%。与FA相比,ASA与羟丙基-β-环糊精络合,其稳定性更强。为提高阿司匹林的稳定性,对一种新型FA络合剂进行了研究。与1：1ASA-FA喷雾干燥络合物相比,ASA与羟丙基-β-环糊精1：1络合时,ASA的稳定性有显著改善。     

Evaluation of Antioxidant Activities in Relation to Total Phenolics and Flavonoids Content of Selected Malaysian Wild Edible Plants by Multivariate Analysis

The aim of this study was to determine the antioxidant activity, total phenolics, and total flavonoid content of six freeze dried wild edible plants, namely Helminthostachys zeylanica, Schismatoglottis ahmadii, Heckeria umbelatum, Lasia spinosa, Gonostegia hirta, and Aniseia martinicense from Sabah, Malaysia. All leaves had higher levels of total phenolics, flavonoids, and antioxidant activity than stems and flowers for all extracts, except the stem of Gonostegia hirta. Integrated antioxidant activity index showed the leaf of Heckeria umbellatum and Aniseia martinicense possessed the highest antioxidant activity for all extracts. Principal component analysis identified that the phenolic group present in the hot water and methanolic extracts was the main factor for higher values observed in oxygen radical absorbance capacity and ferric reducing antioxidant power assays. These wild edible plants are good natural sources of antioxidants to be incorporated as functional ingredients in the food industry.     

Wind energy estimation at Quetta

Hourly wind data at Quetta airport (Samungli) for the years 1984–1985, were obtained using a standard anemometer height of 10 m, with a view to work out the feasibility of wind energy utilization. Quetta (lat. 30°11 'N long. 66°57'E) is elevated at 1799 m above sea level. In this paper, we analyse the wind energy data by using the Weibull distribution. Scaling and shaping parameters are determined by using least-squares approximation to a straight line. Actual wind data, weighted Weibull density function and weighted Rayleigh probability density function for regular and continuous periods of 4 weeks up to a year (wind characteristics are being recorded and summarized as diurnal and monthly wind velocity distributions and wind power density roses) are plotted which shows that the Weibull distribution is generally of the right shape to fit low-averaged wind speed frequency curves. However, density function of a normal distribution is also determined. Deviations in wind speed distributions at very low-averaged wind speeds and at comparatively large-averaged wind speeds are found.     

Electrospinning of hollow and core/sheath nanofibers using a microfluidic manifold

In this article, we describe a microfluidic approach to fabricate hollow and core/sheath nanofibers by electrospinning. Key benefits in using microfluidic devices for nanofiber synthesis include rapid prototyping, ease of fabrication, and the ability to spin multiple fibers in parallel through arrays of individual microchannels. Hollow poly (vinylpyrrolidone) (PVP) + titania (TiO₂) composite and core/sheath polypyrrole (PPy)/PVP nanofibers of the order of 100 and 250 nm, respectively, were successfully fabricated using elastomeric microfluidic devices. Fiber characterization was subsequently carried out using a combination of scanning electron microscopy and transmission electron microscopy.     

In situ Endothelialization: Bioengineering Considerations to Translation

Improving patency rates of current cardiovascular implants remains a major challenge. It is widely accepted that regeneration of a healthy endothelium layer on biomaterials could yield the perfect blood‐contacting surface. Earlier efforts in pre‐seeding endothelial cells in vitro demonstrated success in enhancing patency, but translation to the clinic is largely hampered due to its impracticality. In situ endothelialization, which aims to create biomaterial surfaces capable of self‐endothelializing upon implantation, appears to be an extremely promising solution, particularly with the utilization of endothelial progenitor cells (EPCs). Nevertheless, controlling cell behavior in situ using immobilized biomolecules or physical patterning can be complex, thus warranting careful consideration. This review aims to provide valuable insight into the rationale and recent developments in biomaterial strategies to enhance in situ endothelialization. In particular, a discussion on the important bio‐/nanoengineering considerations and lessons learnt from clinical trials are presented to aid the future translation of this exciting paradigm.     

Transforming South Africa’s low-income housing projects through backyard dwellings: intersections with households and the state in Alexandra, Johannesburg

South Africa’s ‘housing programme’ transfers a fully-funded serviced site and house to qualifying beneficiaries with aims of progressively addressing poverty through homeownership. Despite delivering close to 3 million houses since 1994, informal housing persists, featuring even in some of these new neighbourhoods. This paper focuses on the intersection between a particular mode of informal housing, backyard dwellings, and state-subsidised low-income housing projects. Backyard dwellings arguably contradict state housing objectives by symbolising informality and disorder; a symptom of inadequacy that the housing programme strives to overcome. We consider first the views and experiences of landlords (owners of state-subsided houses) and tenants (occupiers of privately-provided backyard dwellings) in a section of Alexandra, Johannesburg. We then reflect on the potential of backyard accommodation within post-apartheid housing delivery, arguing that despite challenges, the phenomenon of planned, state-led infrastructure generating secondary accommodation represents an opportunity rather than an example of failed modernity. South Africa’s backyard dwellings resonate with similar forms of self-funded and managed rental stock across the global South. As a quick, flexible and regenerative housing asset, cumulative acceptance of such rental markets is necessary—along with viewing the driving actors as astute innovators in shelter and livelihood provision.     

Erosion–Corrosion of Low Carbon (AISI 1008 Steel) Ring Gasket Under Dynamic High Pressure CO2 Environment

R39 AISI 1008 steel ring gasket, used as sealing element in choke valve of a gas well, suffered erosion–corrosion after being used for a relatively short time, which resulted in the leakage of gas. Scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and hardness testing were used to determine the most probable causes of the failure. The results showed that the composition and hardness of ring gasket were in accordance with the required parameters of API 6A Style R39, Class D ring gasket, and AISI 1008 steel. The composition of corrosion products were mainly Fe₂O₃, Fe₃O₄ and scaling layer were composed of FeCO₃. The investigations indicated that failure of the ring gasket was caused by erosion–corrosion.     

Examining driver injury severity in two vehicle crashes – A copula based approach

A most commonly identified exogenous factor that significantly affects traffic crash injury severity sustained is the collision type variable. Most studies consider collision type only as an explanatory variable in modeling injury. However, it is possible that each collision type has a fundamentally distinct effect on injury severity sustained in the crash. In this paper, we examine the hypothesis that collision type fundamentally alters the injury severity pattern under consideration. Toward this end, we propose a joint modeling framework to study collision type and injury severity sustained as two dimensions of the severity process. We employ a copula based joint framework that ties the collision type (represented as a multinomial logit model) and injury severity (represented as an ordered logit model) through a closed form flexible dependency structure to study the injury severity process. The proposed approach also accommodates the potential heterogeneity (across drivers) in the dependency structure. Further, the study incorporates collision type as a vehicle-level, as opposed to a crash-level variable as hitherto assumed in earlier research, while also examining the impact of a comprehensive set of exogenous factors on driver injury severity. The proposed modeling system is estimated using collision data from the province of Victoria, Australia for the years 2006 through 2010.     

Toward a Consensus Model of the hERG Potassium Channel

Malfunction of hERG potassium channels, due to inherited mutations or inhibition by drugs, can cause long QT syndrome, which can lead to life‐threatening arrhythmias. A three‐dimensional structure of hERG is a prerequisite to understand the molecular basis of hERG malfunction. To achieve a consensus model, we carried out an extensive analysis of hERG models based on various alignments of helix S5. We analyzed seven models using a combination of conventional geometry/packing/normality validation methods as well as molecular dynamics simulations and molecular docking. A synthetic test set with the X‐ray crystal structure of K_v1.2 with artificially shifted S5 sequences modeled into the structure served as a reference case. We docked the known hERG inhibitors (+)‐cisapride, (S)‐terfenadine, and MK‐499 into the hERG models and simulation snapshots. None of the single analyses unambiguously identified a preferred model, but the combination of all three revealed that there is only one model that fulfils all quality criteria. This model is confirmed by a recent mutation scanning experiment (P. Ju, G. Pages, R. P. Riek, P. C. Chen, A. M. Torres, P. S. Bansal, S. Kuyucak, P. W. Kuchel, J. I. Vandenberg, J. Biol. Chem. 2009 , 284, 1000–1008). 1 We expect the modeled structure to be useful as a basis both for computational studies of channel function and kinetics as well as the design of experiments.