Simple Pendulum Revisited

We describe a 8085 microprocessor interface developed to make reliable time period measurements. The time period of each oscillation of a simple pendulum was measured using this interface. The variation of the time period with increasing oscillation was studied for the simple harmonic motion (SHM) and for large angle initial displacements (non-SHM). The results underlines the importance of the precautions which the students are asked to take while performing the pendulum experiment.Comment: 17 pages with 10 figure

1,2,4-TRIAZOLES: SYNTHETIC STRATEGIES AND PHARMACOLOGICAL PROFILES

Multicomponent, solid-phase, microwave and grinding methods are the constructive modes in the sustainable synthesis of 1, 2, 4-triazoles and such reactions have attracted enormous interest in recent years. The alternative reaction conditions getting popularity in the recent ecofriendly-economical time have been thoroughly investigated. Literature studies on 1, 2, 4-triazoles have shown that these derivatives possess broad spectrum of biological activities. This review focuses on synthetic strategies and pharmacological properties of 1, 2, 4-triazoles

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

SYNTHESIS AND ANTIBACTERIAL SCREENING OF FEW NEW 5-MEMBERED HETEROCYCLIC SUGAR HYDRAZONES

Objective: The aim of this study is to synthesize, characterize, and screen some new 5-membered heterocyclic sugar hydrazones for their antibacterialactivities.Methods: A library of sugar hydrazones containing 2-benzofuryl, 2-thiophenyl, and 2-pyrrolyl motifs were synthesized. Structures of the newlysynthesized compounds were deduced based on spectral data and elemental analyses.Results: Antibacterial activity was screened against Gram-positive and Gram-negative bacterial strains. Results were compared to gentamicin.Compound 6a exhibited most potent antibacterial activity against all the tested strains.Conclusion: 2-benzofuryl derivatives were observed to be good antibacterials.Keywords: Benzofuran, Thiophene, Pyrrole, Antibacterial, Sugar

Unraveling the Shift to the Entrepreneurial Economy

A recent literature has emerged providing compelling evidence that a major shift in the organization of the developed economies has been taking place: away from what has been characterized as the managed economy towards the entrepreneurial economy. In particular, the empirical evidence provides consistent support that (1) the role of entrepreneurship has significantly increased, and (2) a positive relationship exists between entrepreneurial activity and economic performance. However, the factors underlying this observed shift have not been identified in a systematic manner. The purpose of this paper is to suggest some of the factors leading to this shift and implications for public policy. In particular, we find that a fundamental catalyst underlying the shift from the managed to the entrepreneurial economy involved the role of technological change. However, we also find that it was not just technological change but rather involved a number of supporting factors, ranging from the demise of the communist system, increased globalization, new competition for multinational firms and higher levels of prosperity. Recognition of the causes of the shift from the managed to the entrepreneurial economy suggests a rethinking of the public policy approach. Rather than the focus of directly and exclusively on promoting startups and SMEs, it may be that the current approach to entrepreneurship policy is misguided. The priority should not be on entrepreneurship policy but rather a more pervasive and encompassing approach, policy consistent with an entrepreneurial economy

Computerised control and data acquisition for corrosion experiments

Electrochemical measurement of corrosion involves imposition of electrical perterbation in the form of potential or current on the test specimen and measuring its response. A potentiostat is most frequently used for this purpose. The present paper describes a menu driven user friendly software developed for corrosion analysis by interfacing the potentiostat with PC-AT. The system was developed around a laboratory developed potentiostat and a PC/AT 486.The interface between the two was devel-oped using a PC plug in PCL 208A card with nominal speci-fications : AD 16 ch., DA 2ch, res 12 bits, max. frequency 100 KHz. The DA channels were modified for bipolar output and fine turfing of potential. Corrosion rates are measu-red by (i) linear polarisation, (ii) Tafel analysis and (iii) increasing pulse polarisation. The corrosion rate is calculated using Stern Greary equation with Rp measured from the polarisation data and known tafel slopes. Alterna-tively it is calculated using a nonlinear least square alg-orithm. Besides corrosion measurement the system is also used for other experiments like potentiodynamic polari-sation, pitting, cyclic voltametry, EPR and transients. The specification for the present system are : control potential range ±2V, resolution 0.488 mV, current sensit-ivity 0.1 uA, scan rate 0.26 uVlsec to 20 Vlsec, pulse potential 1.2 mV to 5V, pulse time 250 ms. to 72 mins. Completely arbitrary waveform can be generated and imposed on specimens. The software has facility for preview of potential wafeform, simultaneous display of acquired potential/current data, drawing of lines and tangents, data viewing and editing and calculation of different corrosion and electrochemical parameters

Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design.

Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer

Future Logistics: What to Expect, How to Adapt

As a result of global societal and economic as well as technological developments logistics and supply chains face unprecedented challenges. Climate change, the need for more sustainable products and processes, major political changes, the advance of “Industry 4.0” and cyber-physical system are some of the challenges that require radical solutions, but also present major opportunities. The authors argue that logistics has to reinvent itself, not only to address these chal-lenges but also to cope with mass individualization on the one hand while exploit-ing broad-fielded business applications of artificial intelligence on the other hand. An essential challenge will be to find a compromise between these two develop-ments – in line and in combination with the known triple-bottom line for sustaina-bility – that will define supply chains and logistics concepts of the future

Sensitivity of the Advanced LIGO detectors at the beginning of gravitational wave astronomy

The Laser Interferometer Gravitational Wave Observatory (LIGO) consists of two widely separated 4 km laser interferometers designed to detect gravitational waves from distant astrophysical sources in the frequency range from 10 Hz to 10 kHz. The first observation run of the Advanced LIGO detectors started in September 2015 and ended in January 2016. A strain sensitivity of better than 10−23/Hz−−−√ was achieved around 100 Hz. Understanding both the fundamental and the technical noise sources was critical for increasing the astrophysical strain sensitivity. The average distance at which coalescing binary black hole systems with individual masses of 30  M⊙ could be detected above a signal-to-noise ratio (SNR) of 8 was 1.3 Gpc, and the range for binary neutron star inspirals was about 75 Mpc. With respect to the initial detectors, the observable volume of the Universe increased by a factor 69 and 43, respectively. These improvements helped Advanced LIGO to detect the gravitational wave signal from the binary black hole coalescence, known as GW150914

Benzothiazinones kill Mycobacterium tuberculosis by blocking arabinan synthesis

New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe the synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class of antimycobacterial agents that kill Mycobacterium tuberculosis in vitro, ex vivo, and in mouse models of TB. Using genetics and biochemistry, we identified the enzyme decaprenylphosphoryl-beta-d-ribose 2'-epimerase as a major BTZ target. Inhibition of this enzymatic activity abolishes the formation of decaprenylphosphoryl arabinose, a key precursor that is required for the synthesis of the cell-wall arabinans, thus provoking cell lysis and bacterial death. The most advanced compound, BTZ043, is a candidate for inclusion in combination therapies for both drug-sensitive and extensively drug-resistant TB