Characterization of Freshwater Natural Dissolved Organic Matter (DOM): Mechanistic Explanations for Protective Effects Against Metaltoxicity and Direct Effects on Organisms

Dissolved organic matter (DOM) exerts direct and indirect influences on aquatic organisms. In order to better understand how DOM causes these effects, potentiometric titration was carried out for a wide range of autochthonous and terrigenous freshwater DOM isolates. The isolates were previously characterized by absorbance and fluorescence spectroscopy. Proton binding constants (pKa) were grouped into three classes:acidic (pKa ≤ 5), intermediate (5 \u3c pKa ≤ 8.5) and basic (pKa \u3e 8.5). Generally, the proton site densities (LT) showed maximum peaks at the acidic and basic ends around pKa values of 3.5 and 10, respectively. More variably positioned peaks occurred in the intermediate pKa range. The acid–base titrations revealed the dominance of carboxylic and phenolic ligands with a trend for more autochthonous sources to have higher total LT. A summary parameter, referred to as the Proton Binding Index (PBI), was introduced to summarize chemical reactivity of DOMs based on the data of pKa and LT. Then, the already published spectroscopic data were explored and the specific absorbance coefficient at 340 nm (i.e. SAC340), an index of DOM aromaticity,was found to exhibit a strong correlation with PBI. Thus, the tendencies observed in the literature that darker organic matter is more protective against metal toxicity and more effective in altering physiological processes in aquatic organisms can now be rationalized on a basis of chemical reactivity to protons

The Influence of Dissolved Organic Matter (DOM) on Sodium Regulation and Nitrogenous Waste Excretion in the Zebrafish (Danio rerio)

Dissolved organic matter (DOM) is both ubiquitous and diverse in composition in natural waters, but its effects on the branchial physiology of aquatic organisms have received little attention relative to other variables (e.g. pH, hardness, salinity, alkalinity). Here, we investigated the effects of four chemically distinct DOM isolates (three natural, one commercial, ranging from autochthonous to highly allochthonous, all at ∼6 mg C l−1) on the physiology of gill ionoregulation and nitrogenous waste excretion in zebrafish acclimated to either circumneutral (7.0–8.0) or acidic pH (5.0). Overall, lower pH tended to increase net branchial ammonia excretion, net K+ loss and [3H]PEG-4000 clearance rates (indicators of transcellular and paracellular permeability, respectively). However, unidirectional Na+ efflux, urea excretion and drinking rates were unaffected. DOM sources tended to stimulate unidirectional Na+ influx rate and exerted subtle effects on the concentration-dependent kinetics of Na+ uptake, increasing maximum transport capacity. All DOM sources reduced passive Na+ efflux rates regardless of pH, but exerted negligible effects on nitrogenous waste excretion, drinking rate, net K+ loss or [3H]PEG4000 clearance, so the mechanism of Na+ loss reduction remains unclear. Overall, these actions appear beneficial to ionoregulatory homeostasis in zebrafish, and some may be related to physicochemical properties of the DOM sources. They are very different from those seen in a recent parallel study on Daphnia magna using the same DOM isolates, indicating that DOM actions may be both species and DOM specific

Carcass characteristics of Karadi lambs as affect by different levels of dietary supplement of rumen degradable nitrogen fed with Nigella sativa

The objective of the work described here was to investigate the effect of two levels of Nigella sativa (0 and 7.5 g NS / kg DM) supplementation to rations of Karadi lambs fed three levels of rumen degradable nitrogen (1, 1.3 and 1.6 g RDN / MJ of ME) on carcass characteristics, using 2 x 3 factorial experiment. Twenty four individual Karadi male lambs were used (four lambs for each treatment). They were weighing approximately 30 kg live weight and 7 months old. The diets were formulated to be given at40% NaOH-treated barley straw DM to 60% concentrates DM. At the end of feeding trial, all the lambs were slaughtered after over night with feeding straw. Live weight gain was improved (P < 0.05) in lambs fed diets supplemented with NS as compared with those lambs fed diet without NS. However, live weight gain was not affected by levels of RDN. Changes in slaughter weight, Killing out proportion, leg cuts tissue, the wholesale cuts weight and fat-tail weight were not significantly affected by both NSsupplementation and levels of RDN. However, the heavier slaughter weights, cold carcass and fat tail weights were associated with lambs fed highest level of RDN supplemented with NS (P < 0.05). Moreover, there is a linear increase in fat-tail weight associated with lambs fed increasing levels of RDN supplemented with NS

Carcass yield and characteristics of Karadi lambs as affected by dietary supplement of rumen undegradable nitrogen fed with Nigella sativa

The objective of this work was to investigate the effect of two levels of rumen undegradable nitrogen (7 and 10 g UDN/kg DM) fed with two levels of Nigella sativa (0 and 7.5 g NS/ kg DM) supplementation to rations of karadi lambs on carcass characteristics, using 2 x 2 factorial experiment. Sixteen individual Karadi male lambs were used (four lambs for each treatment). They were weighing approximately 34 kg live weight and 7 months old. The diets were formulated to be given a 40% NaOH-treated barley straw DM to 60% concentrates DM. At the end of feeding trial the lambs were slaughtered after over night with feeding draw. Differences in daily nutrients intake among treatments were not statistically significantly. The UDN and total N intake were followed the intended treatments composition (P < 0.01). Live weight gain was not significantly affected by levels of UDN and NS supplementation. Slaughter body weight, hot and cold carcass weights and killing out proportion were not significantly affected by both NS supplementation and levels of UDN. Moreover, no differences in leg cut tissue (lean, subcutaneous fat: intramuscular fat and bone) among treatments. The main wholesale cuts weights were not significantly different among treatments. The differences in fat-tail weights between the NS and UDN treatments were not statistically significant.Key words: Lambs, rumen undegredable nitrogen, Nigella sativa, carcass characteristic

Detection of Methicillin-Resistant Staphylococcus aureus (MRSA) Using Loop Mediated Isothermal Amplification (LAMP)

Staphylococcus aureus is one of the most common pathogens that cause a wide range of infections ranging from skin and soft tissue infections to invasive, life threatening infections. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) substantially increased healthcare burdens associated with Staphylococcal infections because of high morbidity and mortality and increasing the need for efficient and cost-effective screening methods, for high-risk patients. The objective of this study is to develop two molecular methods, real-time PCR and loop-mediated isothermal amplification (LAMP), and validate them following Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathologists (CAP) standards. The real time PCR assay was developed targeting mecA, mecC, nuc, and coa to detect S. aureus and methicillin-resistance. The assay had high precision, a linear range of 104-108 CFU/ml, and 95% accuracy. The assay detects MRSA, MSSA, MR-CoNS, and MS CoNS. The LAMP assay was developed targeting the same genes; however, its lower limit of detection was 106 CFU/ml, which was much higher than that of the real-time PCR assay. Additional studies are required to optimize the performance characteristics of the LAMP assay further. Nevertheless, the real-time PCR assay developed in this study will be useful for the detection of MRSA in a cost-effective manner

A new concept of adaptive complexity

Animate systems can organize their complexities to stay alive. They run in easiest ways within specific boundaries to keep their existence and to maintain highest levels of interaction with their surrounding environments. They are (living) systems of emergent (adaptive) and evolved (survived) complexities. The focus here will be on adaptive complexities of their flexible structures. Man-made systems, like cities, are constructed and shaped by instant and accumulative human decisions. Metaphorical questions about the possibility of these systems to behave alike are re-raised. It is argued that their emergent (generative) processes according to optimal combinations of physical and visual connections would enhance their adaptivity. A different method, derived from space syntax, provides a new tool for detecting and estimating these adaptive complexities. It provides measurable dimensions, as sensitive indicators, of adaptive complexities and explains how their continual and generative (size-dependence) processes emerge. In (2D) systems, it is found that organized complexities have adaptive dimensions of fractal values approach to (DA≈1-2). Also, from results on the grounds, each existing urban fabric has a structure with a specific and comparable local and global adaptive dimension. More supportive researches and applications in various (2D) and (3D) systems are needed to develop the concept

Qualitative Assessment of Pollution Indices for Heavy Metal of The Drinking Water in Kirkuk City, Northern Iraq

The purpose of this study is to determined and examined the qualitative  status of water, with respect to the methods of  heavy metal contamination indices for the drinking water quality of Kirkuk city. The 26 samples have collected in July 2015. The heavy metal concentrations were determined in the drinking water samples by using (ICP-MS) technique. Seven heavy metal concentrations including AS,Cr,Cu,Mn,Pb,Ni, and Zn which have been detected in drinking water, were measured in the selected samples of the Kirkuk city. Then by using quality indices based on heavy metals, Cd, HEI and MI, the impact on the quality of drinking water were measured and evaluated. The results show that the metal pollution of drinking water in the study area is frequently less than the threshold risk. The mean HEI (0.465) was found to be below the heavy metal pollution index value of 400. The result of the MI(0.863) elucidates that the drinking water is pure with regard to heavy metal pollution. The results show that the concentrations of 7 studied metals are little than national standards. Comparing the results of heavy metals concentration in this study with drinking water standards displays that the concentration of studied heavy metals are little than the estimated levels that were announced by the World Health Organization(WHO) and the National Standards Organization of Iraq(IQS). Keywords: Heavy Metal, Drinking Water, Water Quality ,Kirku

Release of soluble metal ions from copper based dental alloys mesured by ICP-MS

Describes the release of soluble metal ions from copper based dental alloys mesured by ICP-MS. Presented at the annual congress of the british toxicology society

Computational analysis of smile weight distribution across the face for accurate distinction between genuine and posed smiles

YesIn this paper, we report the results of our recent research into the understanding of the exact distribution of a smile across the face, especially the distinction in the weight distribution of a smile between a genuine and a posed smile. To do this, we have developed a computational framework for the analysis of the dynamic motion of various parts of the face during a facial expression, in particular, for the smile expression. The heart of our dynamic smile analysis framework is the use of optical flow intensity variation across the face during a smile. This can be utilised to efficiently map the dynamic motion of individual regions of the face such as the mouth, cheeks and areas around the eyes. Thus, through our computational framework, we infer the exact distribution of weights of the smile across the face. Further, through the utilisation of two publicly available datasets, namely the CK+ dataset with 83 subjects expressing posed smiles and the MUG dataset with 35 subjects expressing genuine smiles, we show there is a far greater activity or weight distribution around the regions of the eyes in the case of a genuine smile.Supported in part by the European Union's Horizon 2020 Programme H2020-MSCA-RISE-2017, under the project PDE-GIR with grant number 778035