ANTIBACTERIAL PROPERTIES OF ZINC OXIDE NANOPARTICLES SYNTHESIZED BY THE SUPERNATANT OF WEISSELLA CONFUSA UPM22MT04

This study was aimed to produce zinc oxide nanoparticles (ZnO-NPs) using the supernatant of Weissella confusa UPM22MT04 and assess their effectiveness in inhibiting methicillin-resistant Staphylococcus aureus (MRSA). An isolate of Weissella confusa UPM22MT04 was isolated from a wastewater treatment plant in Johor, Malaysia, and was utilized to synthesize ZnO-NPs. The synthesized ZnO-NPs were characterized through several techniques, including UV-visible spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and dynamic light scattering. Monodisperse spherical ZnO-NPs of 1.7 - 7.9 nm were obtained with 0.1 M zinc nitrate at 80°C. The biosynthesized ZnO-NPs exhibited vigorous inhibitory activity against MRSA. Results found that ZnO-NPs inhibited MRSA at a minimum concentration of 0.625 mg/mL and were bactericidal at a minimum concentration of 1.25 mg/mL. In MTT assays, ZnO-NPs showed no toxicity to HS-27 fibroblasts. The supernatant of Weissella confusa UPM22MT04 could be used to synthesize ZnO-NPs, which are an antibacterial agent, eco-friendly and non-toxic

The parental care behaviour of Paratilapia polleni (Perciformes, Labroidei), a phylogenetically primitive cichlid from Madagascar, with a discussion of the evolution of maternal care in the family Cichlidae

The parental behaviour of the Madagascan cichlid, Paratilapia polleni , was studied in the laboratory. According to current hypotheses of phylogenetic intrarelationship for the family Cichlidae, Paratilapia is a representative of a phylogenetically primitive cichlid lineage, and as such is of particular interest in comparative evolutionary studies. Given the basal phylogenetic placement of Paratilapia it seems reasonable to expect that, if maternal participation in brood care arose within the extant Cichlidae, then the proposed plesiomorphic system of extensive male care of eggs and embryos may be retained in this taxon. This is not the case, and already by the fertilized-egg interval male and female roles in Paratilapia are strongly differentiated with the female as the primary care giver. In addition to specialized behavioural roles, a unique egg morphology and mobile egg mass is described for Paratilapia . The results of the study are discussed in the context of theories of the evolution of maternal brood care within the Cichlidae.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42636/1/10641_2004_Article_BF00004768.pd

Magnetic Compton scattering study of the ferromagnetic amorphous alloys Fe1-xBx

The boron contribution to the total spin moment in the amorphous alloys Fe1-xBx (x=0.2,0.24) has been determined using magnetic Compton scattering. The magnitude of the induced boron moment was found to be ≈-0.04μB per formula unit which is a factor of ≈2 less than that suggested by supercell linearized muffin-tin orbital electronic structure calculations. © 2001 The American Physical Society

Improved sea level record over the satellite altimetry era (1993–2010) from the Climate Change Initiative project

Sea level is one of the 50 Essential Climate Variables (ECVs) listed by the Global Climate Observing System (GCOS) in climate change monitoring. In the past two decades, sea level has been routinely measured from space using satellite altimetry techniques. In order to address a number of important scientific questions such as "Is sea level rise accelerating?", "Can we close the sea level budget?", "What are the causes of the regional and interannual variability?", "Can we already detect the anthropogenic forcing signature and separate it from the internal/natural climate variability?", and "What are the coastal impacts of sea level rise?", the accuracy of altimetry-based sea level records at global and regional scales needs to be significantly improved. For example, the global mean and regional sea level trend uncertainty should become better than 0.3 and 0.5 mm year?1, respectively (currently 0.6 and 1–2 mm year?1). Similarly, interannual global mean sea level variations (currently uncertain to 2–3 mm) need to be monitored with better accuracy. In this paper, we present various data improvements achieved within the European Space Agency (ESA) Climate Change Initiative (ESA CCI) project on "Sea Level" during its first phase (2010–2013), using multi-mission satellite altimetry data over the 1993–2010 time span. In a first step, using a new processing system with dedicated algorithms and adapted data processing strategies, an improved set of sea level products has been produced. The main improvements include: reduction of orbit errors and wet/dry atmospheric correction errors, reduction of instrumental drifts and bias, intercalibration biases, intercalibration between missions and combination of the different sea level data sets, and an improvement of the reference mean sea surface. We also present preliminary independent validations of the SL_cci products, based on tide gauges comparison and a sea level budget closure approach, as well as comparisons with ocean reanalyses and climate model outputs

Ages of lunar impact breccias: Limits for timing of the Imbrium impact

Since the Apollo 14 mission delivered samples of the Fra Mauro formation, interpreted as ejecta of the Imbrium impact, defining the age of this impact has emerged as one of the critical tasks required for the complete understanding of the asteroid bombardment history of the Moon and, by extension, the inner Solar System. Significant effort dedicated to this task has resulted in a substantial set of ages centered around 3.9 Ga and obtained for the samples from most Apollo landing sites using a variety of chronological methods. However, the available age data are scattered over a range of a few tens of millions of years, which hinders the ability to distinguish between the samples that are truly representative of the Imbrium impact and those formed/reset by other, broadly contemporaneous impact events. This study presents a new set of U-Pb ages obtained for the VHK (very high K) basalt clasts found in the Apollo 14 breccia sample 14305 and phosphates from (i) several fragments of impact-melt breccia extracted from Apollo 14 soil sample 14161, and (ii) two Apollo 15 breccias 15455 and 15445. The new data obtained for the Apollo 14 samples increase the number of independently dated samples from this landing site to ten. These Apollo 14 samples represent the Fra Mauro formation, which is traditionally viewed as Imbrium ejecta, and therefore should record the age of the Imbrium impact. Using the variance of ten ages, we propose an age of 3922 ± 12 Ma for this event. Samples that yield ages within these limits can be considered as possible products of the Imbrium impact, while those that fall significantly outside this range should be treated as representing different impact events. Comparison of this age for Imbrium (determined from Apollo 14 samples) with the ages of another eleven impact-melt breccia samples collected at four other landing sites and a related lunar meteorite suggests that they can be viewed as part of Imbrium ejecta. Comprehensive review of 40Ar/39Ar ages available for impact melt samples from different landing sites and obtained using the step-heating technique, suggests that the majority of the samples that gave robust plateau ages are indistinguishable within uncertainties and altogether yield a weighted average age of 3916 ± 7 Ma (95 % conf., MSWD = 1.1; P = 0.13) and a median average age of 3919 + 14/-12 Ma, both of which agree with the confidence interval obtained using the U-Pb system. These samples, dated by 40Ar/39Ar method, can be also viewed as representing the Imbrium impact. In total 36 out of 41 breccia samples from five landing sites can be interpreted to represent formation of the Imbrium basin, supporting the conclusion that Imbrium material was distributed widely across the near side of the Moon. Establishing temporal limits for the Imbrium impact allows discrimination of ten samples with Rb-Sr and 40Ar/39Ar ages about 50 Ma younger than 3922 ± 12 Ma. This group may represent a separate single impact on the Moon and needs to be investigated further to improve our understanding of lunar impact history

The Working Curve and Commodity Storage under Backwardation

There remains controversy over whether the empirical curve relating intertemporal commodity price spreads and stocks, originally drawn by Holbrook Working in 1933 (i.e., the Working curve), is a valid stylized fact in commodity markets. The core of the controversy is the portion of the curve representing commodity stocks under backwardation. In this article we analyze the original data used by Working, plus more disaggregated numbers. We find that the Working curve is indeed valid. The diversity of stockholders and different stockholding motives most likely explain the empirical Working curve relationship. Copyright 2007, Oxford University Press.