Universal spectrum for interannual variability in COADS global air and sea-surface temperatures

Continuous periodogram spectral analyses of 28 years (1961-1988) of seasonal (September-November) mean COADS global surface (air and sea) temperature time-series show that the power spectra follow the universal inverse power law form of the statistical normal distribution. An inverse power law form for power spectra of temporal fluctuations implies long-range temperal correlation and is a signature of self-organized criticality. Universal quantification for self-organized criticality presented in this paper is consistent with a recently developed cell dynamical system model for atmospheric flows, which predicts such non-local connections as intrinsic to quantum-like mechanis governing flow dynamics. -from Author

The 404 MHZ wind profiler to observe precipitation

This article delineates the tropical precipitation and classification of precipitating systems into stratiform and convective type, using the UHF wind profiler located at the Indian tropical station Pune (18°32'N, 73°51'E). Under moderate rain conditions the two signals arising due to clear air motions and precipitation are clearly distinguished in the power spectra. An algorithm with suitable methodology has been developed that separates clear air and precipitation echoes when they are clearly distinguishable as seen in the power spectrum. This was tested for various power spectra and found to work well under moderate rain conditions. The sensitivity of the threshold was tested for the precipitation observed on 25 July 2005. In addition, case studies of stratiform rain (precipitation observed over the site on 26 July 2005, 0800 h IST) and convective system (a thunderstorm observed on 16 May 2004) are presented and discussed. An attempt has been made to fit a Gaussian distribution curve to determine the actual Doppler shift and spectral width. The observed convective and stratiform precipitation is described in terms of reflectivity, maximum spectral width and Doppler velocity gradient in the vertical

Scale-size calculations, energy dissipation rates and height coverage of a 404 MHz wind profiler at IMD, Pune

The 404 MHz wind profiler at the India Meteorological Department, Pune, is the first wind profiler of this frequency in India. Therefore, it is necessary to achieve maximum possible height to get valuable data. UHF wind profilers have better height and time resolution, which enables us to make reliable and correct estimations of the wind at various altitudes at regular spacing above the observational site. The height coverage of the profiler depends upon various factors like power aperture product and the operating wavelength vis-avis scale sizes available in the atmosphere. In this study, daily averaged second moment data archived during clear-air conditions have been used to estimate the scale-size parameters in terms of eddy dissipation rates, which explicitly indicates that more height coverage of a profiler depends only on the availability of the scale sizes in the atmosphere to which the radar is sensitive, and that in turn depends on where in the inertial subrange the operating wavelength resides. Power aperture product at various C2n values has been estimated. This note explicitly explains why the height coverage of the wind profiler at Pune is limited to 6-8 km under clear-air conditions

Seasonal, annual and inter-annual features of turbulence parameters over the tropical station Pune (18°32' N, 73°51' E) observed with UHF wind profiler

The present study is specifically focused on the seasonal, annual and inter-annual variations of the refractive index structure parameter (Cn2) using three years of radar observations. Energy dissipation rates (ε) during different seasons for a particular year are also computed over a tropical station, Pune. Doppler spectral width measurements made by the Wind Profiler, under various atmospheric conditions, are utilized to estimate the turbulence parameters. The refractive index structure parameter varies from 10−17.5 to 10−13 m−2/3 under clear air to precipitation conditions in the height region of 1.05 to 10.35 km. During the monsoon months, observed Cn2 values are up to 1–2 orders of magnitude higher than those during pre-monsoon and post-monsoon seasons. Spectral width correction for various non-turbulent spectral broadenings such as beam broadening and shear broadening are made in the observed spectral width for reliable estimation of ε under non-precipitating conditions. It is found that in the lower tropospheric height region, values of ε are in the range of 10−6 to 10−3 m2 s−3. In summer and monsoon seasons the observed values of ε are larger than those in post-monsoon and winter seasons in the lower troposphere. A comparison of Cn2 observed with the wind profiler and that estimated using Radio Sonde/Radio Wind (RS/RW) data of nearby Met station Chikalthana has been made for the month of July 200

Designing disordered materials using DNA-coated colloids of bacteriophage fd and gold.

DNA has emerged as an exciting binding agent for programmable colloidal self-assembly. Its popularity derives from its unique properties: it provides highly specific short-ranged interactions and at the same time it acts as a steric stabilizer against non-specific van der Waals and Coulomb interactions. Because complementary DNA strands are linked only via hydrogen bonds, DNA-mediated binding is thermally reversible: it provides an effective attraction that can be switched off by raising the temperature only by a few degrees. In this article we introduce a new binary system made of DNA-functionalized filamentous fd viruses of ∼880 nm length with an aspect ratio of ∼100, and 50 nm gold nanoparticles (gold NPs) coated with the complementary DNA strands. When quenching mixtures below the melt temperature Tm, at which the attraction is switched on, we observe aggregation. Conversely, above Tm the system melts into a homogenous particulate 'gas'. We present the aggregation behavior of three different gold NP to virus ratios and compare them to a gel made solely of gold NPs. In particular, we have investigated the aggregate structures as a function of cooling rate and determine how they evolve as function of time for given quench depths, employing fluorescence microscopy. Structural information was extracted in the form of an effective structure factor and chord length distributions. Rapid cooling rates lead to open aggregates, while slower controlled cooling rates closer to equilibrium DNA hybridization lead to more fine-stranded gels. Despite the different structures we find that for both cooling rates the quench into the two-phase region leads to initial spinodal decomposition, which becomes arrested. Surprisingly, although the fine-stranded gel is disordered, the overall structure and the corresponding length scale distributions in the system are remarkably reproducible. Such highly porous systems can be developed into new functional materials.This work would not have been possible without the financial support of various agencies: EE, CPG and ZR thank the Winton Program for the Physics of Sustainability. CPG and ZR acknowledge support from the EU ERC FP7 programme via an advanced fellowship for CPG. RU and SHN received support from the Engineering and Physical Sciences Research Council (EPSRC) for financial support. Work in the GPCS Lab is funded by the BBSRC, UK. DJ acknowledges the financial support from Udayan Care, NTCU and Schlumberger Foundation's FFTF program.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5FD00120

Mycobacterial cultures contain cell size and density specific sub-populations of cells with significant differential susceptibility to antibiotics, oxidative and nitrite stress

The present study shows the existence of two specific sub-populations of Mycobacterium smegmatis and Mycobacterium tuberculosis cells differing in size and density, in the mid-log phase (MLP) cultures, with significant differential susceptibility to antibiotic, oxidative, and nitrite stress. One of these sub-populations (similar to 10% of the total population), contained short-sized cells (SCs) generated through highly-deviated asymmetric cell division (ACD) of normal/long-sized mother cells and symmetric cell divisions (SCD) of short-sized mother cells. The other sub-population (similar to 90% of the total population) contained normal/long-sized cells (NCs). The SCs were acid-fast stainable and heat-susceptible, and contained high density of membrane vesicles (MVs, known to be lipid-rich) on their surface, while the NCs possessed negligible density of MVs on the surface, as revealed by scanning and transmission electron microscopy. Percoll density gradient fractionation of MLP cultures showed the SCs-enriched fraction (SCF) at lower density (probably indicating lipid-richness) and the NCs-enriched fraction (NCF) at higher density of percoll fractions. While live cell imaging showed that the SCs and the NCs could grow and divide to form colony on agarose pads, the SCF, and NCF cells could independently regenerate MLP populations in liquid and solid media, indicating their full genomic content and population regeneration potential. CFU based assays showed the SCF cells to be significantly more susceptible than NCF cells to a range of concentrations of rifampicin and isoniazid (antibiotic stress), H2O2 (oxidative stress),and acidified NaNO2 (nitrite stress). Live cell imaging showed significantly higher susceptibility of the SCs of SC-NC sister daughter cell pairs, formed from highly-deviated ACD of normal/long-sized mother cells, to rifampicin and H2O2, as compared to the sister daughter NCs, irrespective of their comparable growth rates. The SC-SC sister daughter cell pairs, formed from the SCDs of short-sized mother cells and having comparable growth rates, always showed comparable stress-susceptibility. These observations and the presence of M. tuberculosis SCs and NCs in pulmonary tuberculosis patients' sputum earlier reported by us imply a physiological role for the SCs and the NCs under the stress conditions. The plausible reasons for the higher stress susceptibility of SCs and lower stress susceptibility of NCs are discussed

Diabetic fetopathy associated with bilateral adrenal hyperplasia and ambiguous genitalia: a case report

<p>Abstract</p> <p>Introduction</p> <p>Many fetal malformations can occur because of maternal diabetes. However, ambiguous genital organs have never been reported as an associated finding in the literature. This is the first report of associated ambiguous genital organ and bilateral adrenal hyperplasia in a case of diabetic fetopathy.</p> <p>Case presentation</p> <p>A 19-year-old Thai primigravida with familial history of diabetes mellitus (DM) was diagnosed as having gestational DM type 2, based on 100 g oral glucose tolerance test, and was poorly controlled with insulin injections. Delayed targeted ultrasonography at 28 weeks gestation revealed multiple fetal anomalies. The woman underwent low transverse cesarean section at 30 weeks gestation due to preterm labor and transverse lie. The newborn with ambiguous genitalia was delivered but expired after birth. Autopsy findings revealed alobar holoprosencephaly, a prominent forehead, hypotelorism, an absent nose, absent bilateral ears, median cleft lip and palate, preaxial polydactyly of the right hand, accessory spleens, single umbilical artery, markedly enlarged adrenal glands and ambiguous external genitalia The subsequent fetal chromosomal study revealed 46,XX.</p> <p>Conclusion</p> <p>We describe a case of diabetic fetopathy with classic facial malformation and preaxial hallucal polydactyly which has been proposed as a marker of diabetic embryopathy. Bilateral adrenal hyperplasia with ambiguous genitalia, an uncommon associated anomaly, was also identified. It is controversial whether adrenal hyperplasia can be a novel feature of diabetic fetopathy or just a coincidental finding. Further observation and adequate investigation are needed in such cases.</p

Characteristic of enterprise collaboration system and its implementation issues in business management

Collaboration is an extremely useful area for the most of the enterprise systems particularly within Web 2.0 and Enterprise 2.0. The collaboration provides help in enterprise collaboration system (ECS) to achieve the desired goal by unifying completed tasks of employees or people working on a similar or the same task. Thus, the collaboration systems have witnessed significant attention. The ECS provides consistent and off-the-shelf support to processes and managements within organisations. Management techniques of the ECS may be useful to a community which manages ECS systems for collaboration. In this context, this paper focuses on enterprise collaboration system and answers critical questions related to ECS including: 1) what does collaboration really means for an enterprise system; 2) how can the collaboration help to improve internal processes and management of the system; 3) how it is helpful to improve interactions with customers and partners

Molecular Valves for Controlling Gas Phase Transport Made from Discrete Angstrom-Sized Pores in Graphene

An ability to precisely regulate the quantity and location of molecular flux is of value in applications such as nanoscale 3D printing, catalysis, and sensor design. Barrier materials containing pores with molecular dimensions have previously been used to manipulate molecular compositions in the gas phase, but have so far been unable to offer controlled gas transport through individual pores. Here, we show that gas flux through discrete angstrom-sized pores in monolayer graphene can be detected and then controlled using nanometer-sized gold clusters, which are formed on the surface of the graphene and can migrate and partially block a pore. In samples without gold clusters, we observe stochastic switching of the magnitude of the gas permeance, which we attribute to molecular rearrangements of the pore. Our molecular valves could be used, for example, to develop unique approaches to molecular synthesis that are based on the controllable switching of a molecular gas flux, reminiscent of ion channels in biological cell membranes and solid state nanopores.Comment: to appear in Nature Nanotechnolog