Analytical‐Based Methodologies for Examining the In Vitro Absorption,Distribution, Metabolism,and Elimination (ADME) of Silver Nanoparticles

The clinical applications of silver nanoparticles (AgNPs) remain limited due to the lack of well‐established methodologies for studying their nanokinetics. Hereby, the primary goal is to adapt a suite of analytical‐based methodologies for examining the in vitro absorption, distribution, metabolism, and elimination of AgNPs. Vero 76 and HEK 293 cells are exposed to ≈10‐nm spherical AgNPs⁺ and AgNPs^? at relevant concentrations (0–300 µg mL^?1) and times (4–48 h). Absorption: Inductively coupled plasma optical emission spectroscopy (ICP‐OES) demonstrates that the two AgNP formulations are not bioequivalent. For example, different bioavailabilities (C _maximum < 20.7 ± 4% and 6.82 ± 0.4%), absorption times (T _maximum > 48 and ≈24 h), and absorption rate laws (first‐ and zeroth‐order at 300 µg mL^?1) are determined in Vero 76 for AgNPs⁺ and AgNPs^?, respectively. Distribution: Raman and CytoViva hyperspectral imaging show different cellular localizations for AgNPs⁺ and AgNPs^?. Metabolism: Cloud point extraction (CPE)‐tangential flow filtration (TFF) reveal that ≤ 11% ± 4% of the administered, sublethal AgNPs release Ag⁺ and contribute to the observed cytotoxicity. Elimination: ICP‐OES‐CPE suggests that AgNPs are cleared via exocytosis.     

Biosynthetic approach for the production of new aminoglycoside derivative

Aminoglycoside antibiotics can be classified into two major groups; streptamine containing and 2-deoxystreptamine containing antibiotics. Here, we report a biosynthetic approach for the fusion of spectinomycin and kanamycin biosynthetic gene clusters to yield the new aminoglycoside derivative, oxykanamycinC, in a non-aminoglycoside producing heterologous host.     

Designing Nanoscale Logic Circuits Based on Markov Random Fields

As devices and operating voltages are scaled down, future circuits will be plagued by higher soft error rates, reduced noise margins and defective devices. A key challenge for the future is retaining high reliability in the presence of faulty devices and noise. Probabilistic computing offers one possible approach. In this paper we describe our approach for mapping circuits onto CMOS using principles of probabilistic computation. In particular, we demonstrate how Markov random field elements may be built in CMOS and used to design combinational circuits running at ultra low supply voltages. We show that with our new design strategy, circuits can operate in highly noisy conditions and provide superior noise immunity, at reduced power dissipation. If extended to more complex circuits, our approach could lead to a paradigm shift in computing architecture without abandoning the dominant silicon CMOS technology.     

Residential fuelwood consumption in the Southeastern U.S.

A telephone survey of households in 13 states in the southeastern U.S. determined residential fuelwood acquisition and use for heating during the 1991 heating season. Although wood burning accounted for only 10% of the total household heat requirement of the region, it accounted for 51% of the total heat requirements of wood-burning households. One-quarter (25%) of the households burned wood, consuming almost 9 million standard cords. Three-quarters (77%) of wood-burning households reported that wood burning contributed to household heating requirements. Wood as a source of home heating was particularly important to low income households, both rural and urban. Wood is the sole source of home heating for 17% of the wood-burning households in the region.     

An assessment by subsistence farmers of the risks to food security attributable to climate change in Makwanpur,Nepal

The potential impacts of climate change on the food security of subsistence farmers is a serious concern. This article explores the food security situations of two categories of subsistence farm households, vegetable- and cereal-based farming systems, in the Makwanpur district of Nepal in the context of climate change. Local climate data for the past 30 years were analyzed. Interviews with local farmers and key informants, and focus group discussions were carried out to collect the primary data. Empirical data showed that changes in climate variables for the study period were in line with farmers’ perceptions and that farming communities were negatively impacted. Perceived impacts were erratic rainfall, increased frequency of floods and droughts, soil degradation and insect pests, weeds and diseases. Farmers have modified traditional cropping patterns and calendar, changed crop varieties and increased fertilizer and pesticide applications in order to maintain crop yields. They have also sought off-farm employment. However, agricultural productivity in the area is declining and only one third of all households in the area were food secure. Household food insecurity was at mild to moderate levels, but vegetable-based households were more secure than cereal-based ones. At the household level, locally successful adaptive measures, such as rainwater harvesting, mulching, planting date adjustments, off-farm opportunities, including infrastructure and extension support, could increase production and contribute to reversing the impact of increased risk attributed to climate change.     

Himalayan waters at the crossroads: issues and challenges

The Hindu Kush Himalayas are called the water towers of Asia as they are the source of 10 major rivers and have the largest snow and ice deposits outside the two poles. Water emanating from the HKH provides food, energy and ecosystem services to up to 1.3 billion people. Climate change and socio-economic and demographic changes have put unprecedented pressure on these water resources, leading to uncertain supplies, increased demands and higher risks of extreme events like floods and droughts. The eight articles in this special issue highlight various dimensions of the Himalayan water resources by focusing on both physical and social science aspects of water management.     

Improving the usability of standard schemas

Due to the development of XML and other data models such as OWL and RDF, sharing data is an increasingly common task since these data models allow simple syntactic translation of data between applications. However, in order for data to be shared semantically, there must be a way to ensure that concepts are the same. One approach is to employ commonly usedschemas—called standard schemas —which help guarantee that syntactically identical objects have semantically similar meanings. As a result of the spread of data sharing, there has been widespread adoption of standard schemas in a broad range of disciplines and for a wide variety of applications within a very short period of time. However, standard schemas are still in their infancy and have not yet matured or been thoroughly evaluated. It is imperative that the data management research community takes a closer look at how well these standard schemas have fared in real-world applications to identify not only their advantages, but also the operational challenges that real users face.     

New shakedown criterion and permanent deformation properties of unbound granular materials

Railway Engineering Science - Unbound granular material specifications for road pavements in Australia are primarily based on physical material specification rather than mechanical...