Sialic acid utilization by Cronobacter sakazakii

Background: The Cronobacter genus is composed of seven species, and can cause infections in all age groups. Of particular concern is C. sakazakii, as this species is strongly associated with severe and often fatal cases of necrotizing enterocolitis and meningitis in neonates and infants. Whole genome sequencing has revealed that the nanAKT gene cluster required for the utilisation of exogenous sialic acid is unique to the C. sakazakii species (ESA_03609-13). Sialic acid is found in breast milk, infant formula, intestinal mucin, and gangliosides in the brain, hence its metabolism by C. sakazakii is of particular interest. Therefore its metabolism could be an important virulence factor. To date, no laboratory studies demonstrating the growth of C. sakazakii on sialic acid have been published nor have there been reports of sialidase activity. The phylogenetic analysis of the nan genes is of interest to determine whether the genes have been acquired by horizontal gene transfer

Draft genome sequences of three newly identified species in the genus Cronobacter, C. helveticus LMG23732T, C. pulveris LMG24059, and C. zurichensis LMG23730T

Cronobacter helveticus, Cronobacter pulveris, and Cronobacter zurichensis are newly described species in the Cronobacter genus, which is associated with serious infections of neonates. This is the first report of draft genome sequences for these species

Draft genome sequence of the earliest Cronobacter sakazakii sequence type 4 strain, NCIMB 8272

The Cronobacter sakazakii clonal lineage defined as sequence type 4 (ST4) is associated with severe cases of neonatal meningitis and persistence in powdered infant formula. For genome sequencing of the earliest deposited culture collection strain of Cronobacter sakazakii ST4, we used the strain NCIMB 8272, originally isolated from milk powder in 1950

Draft genome sequence of a meningitic isolate of Cronobacter sakazakii clonal complex 4, strain 8399

The Cronobacter sakazakii clonal lineage defined as clonal complex 4 (CC4), composed of nine sequence types, is associated with severe cases of neonatal meningitis. To date, only closely related C. sakazakii sequence type 4 (ST4) strains have been sequenced. C. sakazakii strain 8399, isolated from a case of neonatal meningitis, was sequenced as the first non-ST4 C. sakazakii strain

Ujian ricih terus permukaan satah ketakselanjaran granit (Direct shear test of granite discontinuity plane surfaces)

Parameter kekuatan ricih seperti sudut geseran permukaan ketakselanjaran batuan merupakan antara data penting bagi reka bentuk struktur kejuruteraan batuan seperti pengorekan bawah tanah dan cerun potongan. Ujian ricih terus beban normal tetap telah dilakukan pada permukaan buatan potongan gergaji batuan granit segar dan terluluhawa sedikit untuk menentukan sudut geseran asas permukaan satah ketakselanjaran. Sampel granit diperoleh dari Kuari Kajang Rock, Semenyih, Ulu Langat, Selangor, Lebuhraya Silk Kajang (km 14.6), Selangor, Jalan Pos Selim-Kampung Raja (km 30-29), Cameron Highland, Pahang/Perak dan Kuari JKR Bukit Penggorak, Kuantan, Pahang. Sebanyak 84 ujian ricih terus telah dijalankan pada batuan granit iaitu 65 ujian pada batuan segar dan 19 ujian pada batuan terluluhawa sedikit. Untuk batuan granit segar, sudut geseran asas ialah 42° ± 0.6° dengan sisihan piawai sebanyak 2.26 dan pekali penentuan, R2 sebanyak 0.98. Untuk granit terluluhawa sedikit, sudut geseran asas ialah 38° ± 1.9° dengan sisihan piawai sebanyak 3.99 dan pekali penentuan, R2 sebanyak 0.97. Nilai-nilai ini adalah lebih tinggi daripada nilai yang selalu dianggap untuk batuan granit segar iaitu 30°-35°

Keanekaragaman Arthropoda Permukaan Tanah pada Pertanaman Ubikayu (Manihot Utilissima Pohl.) Setelah Perlakuan Olah Tanah dan Pengelolaan Gulma

Penelitian ini bertujuan untuk mengetahui keanekaragaman arthropoda permukaan tanah pada pertanaman ubikayu setelah perlakuan olah tanah dan pengelolaan gulma. Perlakuan disusun dalam rancangan acak kelompok (RAK) dengan empat perlakuan dan empat ulangan. Keempat perlakuan tersebut ialah olah tanah minimum dan pengelolaan gulma secara manual (non herbisida), olah tanah minimum dan pengelolaan gulma dengan herbisida, olah tanah intensif dan pengelolaan gulma dengan herbisida, serta olah tanah intensif dengan pengelolaan gulma non herbisida. Herbisida yang digunakan berbahan aktif glifosat dan 2,4 D dengan dosis 160 ml Bimastar 240/120 SL dalam 1 liter air per ha diaplikasikan pada awal tanam. Pengambilan sampel arthropoda dengan pitfall trap (diameter 9 cm, tinggi 12 cm) dilakukan sebanyak 8 kali dengan selang waktu 1 minggu. Hasil penelitian menunjukkan bahwa kemelimpahan total arthropoda permukaan tanah pada lahan pertanamanubikayu dengan perlakuan pengolahan tanah dan pengelolaan gulma ialah sebanyak 8910 ekor, yang tercakup dalam 10 ordo dan 27 – 29 famili. Diantara ordo dan famili yang diperoleh, dua ordo dan famili dengan kemelimpahan dan kepadatan populasi relatif tertinggi berturut-turut ialah ordo Collembola dan Hymenoptera, serta famili Paronellidae dan Formicidae. Baik perlakuan pengolahan tanah maupun pengelolaan gulma yang dilakukan pada awal tanam tidak berpengaruh terhadap keanekaragaman arthropoda. Besarnya nilai-nilai indeks Shannon-Wiener dan indeks Simpson tergolong dalam kategori sedang. Selain itu juga diketahui bahwa pada keseluruhan lahan perlakuan, arthropoda permukaan tanah yang didapatkan didominasi oleh arthropoda yang berperan sebagai dekomposer dan predator

Aktivitas Antifidan Ekstrak Daun Mint (Mentha Arvensis L.) dan Buah Lada Hitam (Piper Nigrum L.) terhadap Ulat Krop Kubis (Crocidolompa Pavonana F.)

Salah satu hama yang banyak menimbulkan kerusakan pada tanaman kubis adalah Crocidolomia pavonana (F.). Hama ini menyerang bagian krop tanaman kubis. Salah satu alternatif pengendalian hama yang aman terhadap kesehatan manusia dan lingkungan yaitu dengan menggunakan pestisida nabati. Contohnya yang dapat dimanfaatkan sebagai pestisida nabati adalah tanaman mint (Mentha arvensis) dan buah lada hitam (Piper nigrum) diuji dalam penelitian ini melalui 3 tahapan bioassay. Pengamatan aktivitas antifidan dilakukan 24, 48, dan 72 jsa. Peubah yang diamati adalah luas daun yang dimakan larva. Hasil dari bioassay 1 ekstrak daun mint fraksi air memberikan indeks antifidan lebih tinggi (48,74%) dibanding fraksi etil asetat (21,61%) pada 72 jsa. Sedangkan ekstrak buah lada hitam fraksi etil asetat memiliki indeks antifidan lebih tinggi (58,24% ) dibanding fraksi air (33,8%). Oleh karena itu fraksi air ekstrak daun mint dimasukan kedalam diaion HP 20 kolom kromatografi dan dielusi menjadi 100% H2O, 20% MeOH/H2O, 50% MeOH/H2O dan 100% MeOH. Sedangkan fraksi etil asetat ekstrak buah lada hitam dimasukan kedalam di silika kolom kromatografi dan dielusi menjadi 100% CHCl3, 3%MeOH/ CHCl3, 20% MeOH/ CHCl3, dan 100% MeOH. Dari keempat fraksi ini hasil bioassay 2 menunjukkan bahwa ekstrak daun mint fraksi 100% H2O memiliki indeks antifidan lebih tinggi (38,9%) dibandingkan dengan fraksi lainnya. Fraksi 100% CHCl3 ekstrak buah lada hitam mempunyai indeks antifidan lebih tinggi (49,5%) dibandingkan fraksi lainnya. Selanjutnya fraksi 100% H2O dan 100% CHCl3 diuji dengan konsentrasi 40.000 ppm, 20.000 ppm, 10.000 ppm, 5.000 ppm, 2.500 ppm, 1.250 ppm dan kontrol. Dari keenam konsentrasi ini, pada ekstrak daun mint dan buah lada hitam bioassay 3, penggunaan konsentrasi 40.000 ppm pada metode daun tanpa pilihan dan daun pilihan memberikan indeks antifidan tertinggi

Cold pulse and rotation reversals with turbulence spreading and residual stress

Transport modeling based on inclusion of turbulence spreading and residual stresses shows internal rotation reversals and polarity reversal of cold pulses, with a clear indication of nonlocal transport effects due to fast spreading in the turbulence intensity field. The effects of turbulence spreading and residual stress are calculated from the gradient of the turbulence intensity. In the model presented in this paper, the flux is carried by the turbulence intensity field, which in itself is subject to radial transport effects. The pulse polarity inversion and the rotation profile reversal positions are close to the radial location of the stable/unstable transition. Both effects have no direct explanation within the framework of classical transport modeling, where the fluxes are related directly to the linear growth rates, the turbulence intensity profile is not considered and the corresponding residual stress is absent. Our simulations are in qualitative agreement with measurements from ohmically heated plasmas. Rotation reversal at a finite radius is found in situations not displaying saturated confinement, which we identify as situations where the plasma is nearly everywhere unstable. As an additional and new effect, the model predicts a perturbation of the velocity profile following a cold pulse from the edge. This allows direct experimental confirmation of both the existence of residual stress caused by turbulence intensity profiles and fundamental ideas of transport modeling presented here. Published by AIP Publishing

New Thermal Taste Actuation Technology for Future Multisensory Virtual Reality and Internet

Today’s virtual reality (VR) applications are mainly based on audio, visual, and haptic interactions between human and virtual world. Integrating the sense of taste into VR is difficult since we are dependent on chemical-based taste delivery systems. Therefore, developing a proper non-chemical digital taste actuation technology can unlock taste experiences in VR applications such as gaming, multisensory entertainment, remote dining, and online shopping. This paper presents the ‘Thermal Taste Machine’, a new digital taste actuation technology that can effectively produce and modify thermal taste sensations on the tongue. This device changes the temperature of the surface of the tongue within a short period of time (from 25 ◦ C to 40 ◦ C while heating and from 25 ◦ C to 10 ◦ C while cooling). We tested this device on human subjects and described the experience of thermal taste using 20 known (taste and non-taste) sensations. Our results suggested that rapidly heating the tongue produce sweetness, fatty/oiliness, electric taste, warmness, and reduced the sensibility for metallic taste. Similarly, participants reported that the cooling the tongue produced mint taste, pleasantness, and coldness. By conducting an another user study on the perceived sweetness of sucrose solutions after the thermal stimulation, we found that heating the tongue significantly enhanced the intensity of sweetness for both thermal tasters and non-thermal tasters. Also, we found that faster temperature rise on the tongue produce more intense sweet sensations for thermal tasters. We believe that this technology will be useful in two ways: First, it can produce taste sensations without using chemicals for the individuals who are sensitive to thermal taste. Second, the temperature rise of the device can be used as a way to enhance the intensity of sweetness. We believe that this technology can be used to digitally produce and enhance taste sensations in future virtual reality applications. The key novelties of this paper are as follows: 1. Development of a thermal taste actuation technology for stimulating the human taste receptors, 2. Characterization of the thermal taste produced by the device based on a set of taste related sensations and non-taste related sensations, 3. Research on enhancing the intensity for sucrose using thermal stimulation, 4. Research on how different speeds of heating affect the intensity of sweetness produced by thermal stimulation