Low molecular weight oligo-β-hydroxybutyric acids and 3-hydroxy-N-phenethyl-butyramide – new products from microorganisms

Summary A new group of low-molecular weight channel-forming oligo(hydroxybutyric acids) (cPHBs, 1 with n = 8–30; main component MW ≈ 1300 dalton) was isolated from microorganisms of different origin. Inclusion bodies were electron-microscopically visible in cells in the state of autolysis, not in cells in the exponential phase of growth. cPHB and high-molecular poly(l3-hydroxybutyric acid) (sPHB) is cleaved by phenylethylamine and forms the corresponding monomeric hydroxybutyramide and – under drastic conditions, the crotylamide. One of these compounds, the 3-hydroxy-N-phenethyl-butyramide (5), was isolated as a new natural product now. Received: 28 March 2002/Revised version: 26 July 2002/ Accepted: 26 July 2002 RID="*" ID="*"Marine Bakterien, XVII. XVI: R.P. Maskey, R.N. Asolkar, E. Helmke, and H. Laatsch, Chalcomycin B, a new antibiotic from a marine Streptomyces sp. B7064. J. Antibiot., submitted 2002 Correspondence to Hartmut Laatsch, e-mail: hlaatsc@gwdg.de, Fax: +49-551-399660     

Speech segmentation and spoken document processing

Progress in both speech and language processing has spurred efforts to support applications that rely on spoken rather than written language input. A key challenge in moving from text-based documents to such spoken documents is that spoken language lacks explicit punctuation and formatting, which can be crucial for good performance. This article describes different levels of speech segmentation, approaches to automatically recovering segment boundary locations, and experimental results demonstrating impact on several language processing tasks. The results also show a need for optimizing segmentation for the end task rather than independently.     

A Basic Firewall Configuration Strategy for the Protection of Development-related Computer Networks and Subnetworks

ABSTRACT

As more and more development-related networks, both instructional and industry related, are being attached to the Internet, the need for protection from hackers becomes evident. This is largely due to the fact that security breaches have reached epidemic proportions. The article therein examines these issues as well as presents a case study for a basic firewall configuration. The logic behind the case study is based on four different modules containing one or more sections: environmental, forward rules, allow ping, and post-routing rules. A figure and source code is provided to indicate how the logic would appear once the plan had been implemented. The example was designed as such in hopes that a more sophisticated and usable product could emerge. In addition, this template could be considered a useful learning and/or teaching resource when teaching basic firewall configurations.     

Single-particle characterization of summertime Antarctic aerosols collected at King George Island using quantitative energy-dispersive electron probe X-ray microanalysis and attenuated total reflection Fourier transform-infrared imaging techniques

Single-particle characterization of Antarctic aerosols was performed to investigate the impact of marine biogenic sulfur species on the chemical compositions of sea-salt aerosols in the polar atmosphere. Quantitative energy-dispersive electron probe X-ray microanalysis was used to characterize 2900 individual particles in 10 sets of aerosol samples collected between March 12 and 16, 2009 at King Sejong Station, a Korean scientific research station located at King George Island in the Antarctic. Two size modes of particles, i.e., PM(2.5-10) and PM(1.0-2.5), were analyzed, and four types of particles were identified, with sulfur-containing sea-salt particles being the most abundant, followed by genuine sea-salt particles without sulfur species, iron-containing particles, and other species including CaCO(3)/CaMg(CO(3))(2), organic carbon, and aluminosilicates. When a sulfur-containing sea-salt particle showed an atomic concentration ratio of sulfur to sodium of >0.083 (seawater ratio), it is regarded as containing nonsea-salt sulfate (nss-SO(4)(2-)) and/or methanesulfonate (CH(3)SO(3)(-)), which was supported by attenuated total reflection Fourier transform-infrared imaging measurements. These internal mixture particles of sea-salt/CH(3)SO(3)(-)/SO(4)(2-) were very frequently encountered. As nitrate-containing particles were not encountered, and the air-masses for all of the samples originated from the Pacific Ocean (based on 5-day backward trajectories), the oxidation of dimethylsulfide (DMS) emitted from phytoplanktons in the ocean is most likely to be responsible for the formation of the mixed sea-salt/CH(3)SO(3)(-)/SO(4)(2-) particles.     

Development and investigation of cellular light weight bio-briquette ash bricks

The present paper deals with the development of cellular light weight bricks using bio-briquette ash. The necessary physical and chemical tests were conducted on a bio-briquette ash sample to investigate its suitability for the development of bricks. Physico-mechanical, durability and thermal conductivity tests were conducted on cellular light weight bio-briquette ash bricks that fulfilled the requirements of Indian standard. The test results of cellular light weight bio-briquette ash bricks were compared with commercially available fly ash bricks. With reference to fly ash bricks, the cellular light weight bio-briquette ash bricks were found 43 % light in weight, having 13 % higher compressive strength and resulted in 66 % lesser thermal conductivity. A small scale model room (1 m × 1 m × 1 m) made up of fly ash bricks was designed. A similar built form for the cellular light weight bio-briquette ash bricks was also modelled. Both the models were analysed for indoor temperature control and cost. When compared with fly ash model room, cellular light weight bio-briquette ash brick model resulted in a 6 % better indoor temperature control and 29 % cost savings. Thus, the developed cellular light weight bio-briquette ash bricks were found suitable as an alternate construction material for non-load bearing walls.     

Free dialysis in Nepal: Logistical challenges explored

Nepal's Ministry of Health began offering free lifetime hemodialysis (HD) in 2016. There has been a large growth in renal replacement therapy (RRT) services offered in Nepal since 2010, when the last known data on the subject was published. In 2016, 42 HD centers existed (223% increase since 2010) serving 1975 end stage renal disease patients (303% increase since 2010); 36 nephrologists were registered (200% increase since 2010), 12 were trained in transplantation, and 790 transplants had been performed to date. We estimate the incidence of end stage renal disease to be 2900 patients (100 per million population). With an annual cost of approximately US$2300 per dialysis patient, offering free dialysis could potentially cost the government US$6.7 million per year, suggesting that 2.1% of the annual health budget would be allocated to 0.01% of the population. The geographic zone surrounding the capital city, Kathmandu, contains 50% of HD centers, but only 14.5% of Nepal's population. Forty‐eight percent of the population lives within zones without HD service, therefore infrastructure challenges exist in providing equitable access to RRT. The aim of this article is to summarize the current statistics of RRT in Nepal.     

Mixing State of Size-Selected Submicrometer Particles During Photochemical and Combustion Events Measured with the Tandem System

A tandem differential mobility analyzer (TDMA) was applied to determine the mixing state of size-resolved submicrometer particles, in an urban area of Gwangju in Korea, when enhanced concentrations of particles were observed (e.g., photochemical and combustion events). The existence of a nonvolatile core was identified after removing volatile species with increasing temperature up to ～250°C. Data showed that in the combustion event, the accumulation mode particles (137–139 nm) increased significantly and they had a nonvolatile core coated with volatile species, while in the photochemical event, the nucleation mode (15–30 nm) particles enhanced and there was no such nonvolatile core (i.e., they were completely evaporated below 250°C). When hygroscopic growth factor (HGF) of the core particles was measured in the combustion event, their values were close to one, suggesting that they consist of nonvolatile and nonhygroscopic species like black carbon. In the photochemical event, the nucleation mode particles were completely evaporated at 250°C and had some volatile fractions at 100°C, unlike pure ammonium sulfate, and had C and S elements in their TEM/EDS data, suggesting that they have an internal mixture of sulfate and organics. Also, the HGF of the remaining particles after removing volatile species at 150°C increased, but not as much as expected for the case of complete evaporation of volatile species at this temperature. Data for evaporative behaviors of laboratory-generated aerosols (i.e., ammonium sulfate and succinic acid) suggest that evaporation of volatile species in a well-mixed mixture was delayed compared to those existing as single species.

Copyright 2013 American Association for Aerosol Research     

Dynamic and seismic performance of old multi-tiered temples in Nepal

Old temples built in ancient time in Nepal are traditional and monumental structures with historic and archaeological importance. It is now an essential issue to evaluate their seismic safety for future earthquakes. Seismic evaluation method needs the fundamental dynamic properties of the temples. In this paper, dynamic properties of selected 10 typical multi-tiered temples are obtained by using the finite element method. Three of those temples are tested by ambient vibration methods under wind-induced excitation to obtain the real dynamic properties and validate the finite element models. Based on validated finite element model from the test, an empirical formula is proposed to estimate the natural period of vibration of Nepalese temples. Seismic capacity evaluation is then performed using the seismic coefficient method. To achieve a more realistic result, 3D dynamic analysis is carried out by the response spectrum method. Results show that the masonry temples in Nepal have fundamental time period less than 0.6 s. Damping ratio lies between 1% and 6%. The most crucial parts of Nepalese temples are the piers between the openings at the base level. Most of the failure modes are associated with tensile and compressive stresses.     

Improving the Stability of R2R Printed 1‐Bit Code Generator through Spin‐Coated Multilayer‐Encapsulation Method

Roll‐to‐roll (R2R) printed electronic devices have great advantages for developing large scale flexible and disposable devices when compared to current Si‐based technology. For practical realization of these advantages, however, R2R printed devices need to surmount device functionality limitations, most urgently high‐power dissipation and poor device stability. To resolve both imperative challenges at once, herein, an all R2R printed complementary metal‐oxide‐semiconductor (CMOS) 1‐bit code generator with spin‐coated multilayer encapsulation method is developed. In order to print CMOS devices by an all‐R2R gravure printing method, electrical amphoteric property of the single walled carbon nanotube (SWCNT) is utilized to fabricate both p‐type and n‐type SWCNT based thin film transistors (TFTs). In addition, printable encapsulating polymeric materials (CYTOP and FG‐3650) are developed to effectively prevent H₂O permeation. The resulting CMOS 1‐bit code generator is able to continuously operate for 2 h under ambient conditions without any variation in output voltage and frequency.     

Assessing public preferences for design and environmental attributes of an urban automated transportation system

This study investigates public preferences toward design and environmental aesthetic attributes of an automated transportation system—Personal Rapid Transit (PRT) in an urban setting. The goal of the study was to understand the perceived visual aesthetic quality of the PRT within diverse architectural and natural elements composing the town's main spatial and visual structure and to separate the various components that determine a cumulative visual experience. We utilized human perceptual judgments as indicators of visual aesthetic quality, and referred to a psychophysical method to assess the perceived visual aesthetic quality of the scenes. Perceptions were captured using a rank ordering process of most and least preferred scenes on presented panels and responses were analyzed using correlation and regression statistical techniques. Results indicate that specific design attributes such as pillar shape or size, and type of fascia, did not emerge as significantly influencing public perception, while the relationship between automated structure and vehicular infrastructure, and the position of the observer are particularly important. Overall findings indicate that studies conducted on automated transportation should consider the effect of context on the perception of the system. The findings improve our understanding of visual strengths and weaknesses of automated transportation structures within the urban environment and can be useful in the planning for similar transportation systems.