Recommendation model based on opinion diffusion

Information overload in the modern society calls for highly efficient recommendation algorithms. In this letter we present a novel diffusion based recommendation model, with users' ratings built into a transition matrix. To speed up computation we introduce a Green function method. The numerical tests on a benchmark database show that our prediction is superior to the standard recommendation methods.Comment: 5 pages, 2 figure

Improved transient silencing of gene expression in the mosquito female Aedes aegypti

Gene silencing using RNA interference (RNAi) has become a widely used genetic technique to study gene function in many organisms. In insects, this technique is often applied through the delivery of dsRNA. In the adult female Aedes aegypti, a main vector of human‐infecting arboviruses, efficiency of gene silencing following dsRNA injection varies greatly according to targeted genes. Difficult knockdowns using dsRNA can thus hamper gene function analysis. Here, by analysing silencing of three different genes in female Ae. aegypti (p400, ago2 and E75), we show that gene silencing can indeed be dsRNA sequence dependent but different efficiencies do not correlate with dsRNA length. Our findings suggest that silencing is likely also gene dependent, probably due to gene‐specific tissue expression and/or feedback mechanisms. We demonstrate that use of high doses of dsRNA can improve knockdown efficiency, and injection of a transfection reagent along with dsRNA reduces the variability in efficiency between replicates. Finally, we show that gene silencing cannot be achieved using siRNA injection in Ae. aegypti adult females. Overall, this work should help future gene function analyses using RNAi in adult females Ae. aegypti, leading towards a better understanding of physiological and infectious processes

Trapped air metamaterial concept for ultrasonic sub-wavelength imaging in water

Funding for this work was provided through the UK Engineering and Physical Sciences Research Council (EPSRC), Grant Numbers EP/N034163/1, EP/N034201/1 and EP/N034813/1.Acoustic metamaterials constructed from conventional base materials can exhibit exotic phenomena not commonly found in nature, achieved by combining geometrical and resonance effects. However, the use of polymer-based metamaterials that could operate in water is difficult, due to the low acoustic impedance mismatch between water and polymers. Here we introduce the concept of “trapped air” metamaterial, fabricated via vat photopolymerization, which makes ultrasonic sub-wavelength imaging in water using polymeric metamaterials highly effective. This concept is demonstrated for a holey-structured acoustic metamaterial in water at 200–300 kHz, via both finite element modelling and experimental measurements, but it can be extended to other types of metamaterials. The new approach, which outperforms the usual designs of these structures, indicates a way forward for exploiting additive-manufacturing for realising polymer-based acoustic metamaterials in water at ultrasonic frequencies.Publisher PDFPeer reviewe

Gaya kepemimpinan KH. R. Sadad MB. Bukhori di Pondok Pesantren Asyrofuddin Conggeang Sumedang

Kepemimpinan di lembaga pendidikan Islam mempengaruhi lingkungan dalam merealisasikan visi dan misi, termasuk kepemimpinan di pondok pesantren. Keberhasilan suatu kepemimpinan bergantung pada gaya kepemimpinan seseorang. Pondok Pesantren Asyrofuddin bertujuan untuk melahirkan generasi yang berakhlak mulia, cerdas, mandiri dan memiliki tanggung jawab. Tujuan itu dapat tercapai dengan pengelolaan yang baik oleh pimpinannya. Peneliti melihat beberapa pondok pesantren ada yang berkembang dan tidak berkembang. Peneliti menemukan bahwa salah satu faktor berkembang dan tidak berkembangnya di sebabkan oleh pengaruh gaya kepemimpinan. Penelitian ini difokuskan pada gaya kepemimpinan KH. R. Sadad MB. Bukhori di Pondok Pesantren Ayrofuddin Metode yang digunakan dalam penelitian ini adalah deskriptif dengan pendekatan kualitatif. Data yang diperoleh berasal dari sumber primer yang diambil dari hasil penelitian dan data sekunder diambil dari buku-buku dan dokumen-dokumen. Sedangkan tekhnik pengumpulan data dengan cara melakukan observasi, dan wawancara. Kepemimpinan KH. R. Sadad MB. Bukhori berdasarkan penelitian mampu mempengaruhi para anggota kepengurusan supaya bekerja sama guna mencapai tujuan yang sama pada Pondok Pesantren Asyropuddin. Pondok Pesantren Asyropuddin tidak lepas dari peran beliau dengan tipe kepemimpinan demokratis, dikatakan demokratis yaitu, beliau mampu menetapkan faktor manusia sebagai faktor utama dan terpenting. Dalam kepemimpinan ini setiap individu sebagai manusia diakui, sehingga setiap keputusan dan pengawasan beliau tidak ditetapkan oleh sepihak namun di tetapkan secara bersama-sama. Upaya-upaya yang dilakukan KH. R. Sadad MB. Bukhori dalam kepemimpinannya di Pondok Pesantren Asyrofuddin, yaitu pengambilan keputusan dengan proses tidak secara sepihak namun dilakukan dengan proses musyawarah begitupun di setiap pengambilan keputusan beliau melakukan pengambilan keputusan dengan cepat dan sigap walaupun permasalah tersebut merupakan permasalahn kecil, komunikasi dengan proses dimana para anggota melakukan komunikasi atasan terhadap bawahan begitupun bawahan terhadap atasan sehingga menimbulkan timbal balik yang menguntungkan antara dua belah pihak namun dalam hal semua itu tidak ada kecanggungan ataupun batasan dalam berpendapat, dan yang terakhir upaya dalam hal pengawasan dengan proses secara langsung terhadap bawahannya namun dengan cara kekeluargaan adapun pengawasan yang dilakukan beliau bukan untuk mencari kesalahan namun lebih kepada mencari solusi. Keberhasilan yang dicapai dari kepemimpinan beliau secara signifikan meningkatnya, yaitu dapat dilihat dari adanya sistem pendidikan yang diterapkan oleh pesantren dan dari perkembangan sarana yang membaik

Improving a gold standard: treating human relevance judgments of MEDLINE document pairs

Given prior human judgments of the condition of an object it is possible to use these judgments to make a maximal likelihood estimate of what future human judgments of the condition of that object will be. However, if one has a reasonably large collection of similar objects and the prior human judgments of a number of judges regarding the condition of each object in the collection, then it is possible to make predictions of future human judgments for the whole collection that are superior to the simple maximal likelihood estimate for each object in isolation. This is possible because the multiple judgments over the collection allow an analysis to determine the relative value of a judge as compared with the other judges in the group and this value can be used to augment or diminish a particular judge’s influence in predicting future judgments. Here we study and compare five different methods for making such improved predictions and show that each is superior to simple maximal likelihood estimates

New Insights into Chloramphenicol Biosynthesis in Streptomyces venezuelae ATCC 10712

Comparative genome analysis revealed seven uncharacterized genes, sven0909 to sven0915, adjacent to the previously identified chloramphenicol biosynthetic gene cluster (sven0916–sven0928) of Streptomyces venezuelae strain ATCC 10712 that was absent in a closely related Streptomyces strain that does not produce chloramphenicol. Transcriptional analysis suggested that three of these genes might be involved in chloramphenicol production, a prediction confirmed by the construction of deletion mutants. These three genes encode a cluster-associated transcriptional activator (Sven0913), a phosphopantetheinyl transferase (Sven0914), and a Na(+)/H(+) antiporter (Sven0915). Bioinformatic analysis also revealed the presence of a previously undetected gene, sven0925, embedded within the chloramphenicol biosynthetic gene cluster that appears to encode an acyl carrier protein, bringing the number of new genes likely to be involved in chloramphenicol production to four. Microarray experiments and synteny comparisons also suggest that sven0929 is part of the biosynthetic gene cluster. This has allowed us to propose an updated and revised version of the chloramphenicol biosynthetic pathway

Bioclimatic Architecture and Urban Morphology. Studies on Intermediate Urban Open Spaces

This paper deals with the interactions between biophysical and microclimatic factors on the one hand with, on the other, the urban morphology of intermediate urban open spaces, the relationship between environmental and bioclimatic thermal comfort, and the implementation of innovative materials and the use of greenery, aimed at the users’ well-being. In particular, the thermal comfort of the open spaces of the consolidated fabrics of the city of Rome is studied, by carrying out simulations of cooling strategies relating to two scenarios applied to Piazza Bainsizza. The first scenario involves the use of cool materials for roofs, cladding surfaces, and pavement, while the second scenario, in addition to the cool materials employed in the first scenario, also includes the use of greenery and permeable green surfaces. The research was performed using summer and winter microclimatic simulations of the CFD (ENVI-met v. 3.1) type, in order to determine the dierent influences of the materials with cold colors, trees, and vegetated surfaces on the thermal comfort of the urban morphology itself. Meanwhile, the comfort assessment was determined through the physiological equivalent temperature (PET) calculated with the RayMan program. The first scenario, with the use of cool materials, improves summer conditions and reduces the urban heat island eect but does not eliminate thermal discomfort due to the lack of shaded surfaces and vegetation. The second scenario, where material renovations is matched with vegetation improvements, has a slightly bad eect on winter conditions but drastically ameliorates the summer situation, both for direct users and, thanks to the strong reduction of the urban heat island eect, to urban inhabitants as a whole

A metallic additively manufactured metamaterial for enhanced monitoring of acoustic cavitation‐based therapeutic ultrasound

The combination of ultrasound and microbubbles allows treatment of indications that would be impossible or too risk adverse with conventional surgery. During treatment, subharmonic and ultraharmonic components that can only be generated from microbubbles are of great interest for intraoperative monitoring. However, the microbubble emissions are several orders of magnitude lower in power compared to that of the fundamental frequency component from the ultrasound applicator, resulting in a low signal‐to‐noise ratio (SNR) for monitoring. A 3D acoustic metamaterial (AMM) immersed in water is proposed for suppressing unwanted ultrasound waves, which allows the improved sensitivity for detecting weak microbubble emissions. Numerically, the importance of shear waves on the AMM transfer properties is highlighted, though only longitudinal ultrasound waves are transmitted through water. Experimentally, the design is implemented in titanium using additive manufacturing, with an attenuation level of 40 dB at the fundamental frequency. Consequently, the application of the AMM efficiently improves the SNR for subharmonic and ultraharmonic microbubble emissions by 11.8 and 11.9 dB, respectively. The subharmonic components originally overwhelmed by noise are recovered. This is the first time that AMMs have been applied to passive acoustic monitoring and this work stands to improve treatment outcomes from cavitation‐mediated focused ultrasound therapy

Exchange Bias in Fe@Cr Core–Shell Nanoparticles

We have used X-ray magnetic circular dichroism and magnetometry to study isolated Fe@Cr core−shell nanoparticles with an Fe core diameter of 2.7 nm (850 atoms) and a Cr shell thickness varying between 1 and 2 monolayers. The addition of Cr shells significantly reduces the spin moment but does not change the orbital moment. At least two Cr atomic layers are required to stabilize a ferromagnetic/antiferromagnetic interface and generate the associated exchange bias and increase in coercivity