Effects of lead contamination on the clonal propagative ability of Phragmites australis (common reed) grown in wet and dry environments

Clonal propagation is important for the survival and maintenance of the common reed Phragmites australis. Pot culture experiments were conducted to investigate the effects of lead (Pb) concentration (0, 500, 1500, 3000, 4500 mg·kg^?1) and water stress on the clonal reproductive ability of this species. The Pb concentration found in plant organs, in decreasing order, was roots >shoots >rhizomes. There was a negative relationship between the growth of clonal propagative modules (excluding axillary shoot buds) and Pb concentrations, which caused a decrease in biomass, rhizome growth and number of axillary and apical rhizome buds. Daughter axillary shoots exhibited a tolerance strategy, with no significant change in their number; the axillary and apical rhizome buds, daughter apical rhizome shoots and rhizomes exhibited compensatory growth during the late stage of Pb (excluding 4500 mg·kg^?1) treatment in a wet environment. Pb applications above 500 mg·kg^?1 reduced these parameters significantly in the drought treatment, except for the number of axillary shoot buds, which did not change. Our results indicate that clonal propagative resistance to Pb contamination can occur via tolerance strategies, compensatory growth and a Pb allocation strategy, enabling these reeds to maintain population stability in wet environments. However, clonal modular growth and reproductive ability were inhibited significantly by the interaction between drought and Pb, which would cause a decline in P. australis populations in a dry environment. Lead concentrations of 4500 and 500 mg·kg^?1 in soils might meet or exceed the Pb tolerance threshold of clonally propagated reeds in wet and dry environments, respectively.     

Survey of stereotypic behavior in prosimians

Captive animals have been observed to perform a variety of stereotypic behaviors. However, little is known about stereotypic behavior in prosimians. We sent surveys to 96 AZA-accredited institutions to examine stereotypic behavior in these primates. Forty-eight surveys were returned, providing information on 440 individuals of 10 genera. According to the responses, 13.2% of the prosimians surveyed exhibited some form of stereotypic behavior. Pacing was the most common behavior. A logistic regression was used to examine intrinsic characteristics that might influence the performance of stereotypic behavior. The genus of the prosimian was a significant predictor of stereotypic behavior. Individuals of the genus Varecia and Microcebuswere more likely to engage in stereotypic behavior than members of the other genera. Rearing history, age, and sex were not significant predictors of stereotypic behavior. To examine the influence of extrinsic variables on stereotypic behavior, we transformed the data into the percentage of individuals within the enclosure that were reported to exhibit stereotypic behavior, and analyzed them at the enclosure level using a general linear model (GLM) analysis of variance (ANOVA). The only environmental variable that significantly predicted stereotypic behavior was the frequency with which enrichment was provided. Frequent enrichment was provided to those exhibits with a higher percentage of prosimians that engaged in stereotypic behavior. The results of this survey suggest that stereotypic behavior in prosimians may be associated with intrinsic factors (i.e., individual or genus differences) in addition to extrinsic factors related to housing. This knowledge may be helpful in identifying the causes of and effective treatments for stereotypic behavior in prosimians.     

Effect of Extracellular pH on Presteady-State and Steady-State Current Mediated bythe Na<Superscript>+</Superscript>/K<Superscript>+</Superscript> Pump

A ouabain sensitive inward current occurs in Xenopus oocytes in Na⁺ and K⁺ -free solutions. Several laboratories have investigated the properties of this current and suggested that acidic extracellular pH (pH_o) produces a conducting pathway through the Na⁺/K⁺ pump that is permeable to H⁺ and blocked by [Na⁺]_o. An alternative suggestion is that the current is mediated by an electrogenic H⁺-ATPase. Here we investigate the effect of pH_o and [Na⁺]_o on both transient and steady-state ouabain-sensitive current. At alkaline or neutral pH_o the relaxation rate of pre-steady-state current is an exponential function of voltage. Its U-shaped voltage dependence becomes apparent at acidic pH_o, as predicted by a model in which protonation of the Na⁺/K⁺ pump reduces the energy barrier between the internal solution and the Na⁺ occluded state. The model also predicts that acidic pH_o increases steady-state current leak through the pump. The apparent pK of the titratable group(s) is 6, suggesting that histidine is involved in induction of the conductance pathway. ²²Na efflux experiments in squid giant axon and current measurements in oocytes at acidic pH_o suggest that both Na⁺ and H⁺ are permeant. The acid-induced inward current is reduced by high [Na⁺]_o, consistent with block by Na⁺. A least squares analysis predicts that H⁺ is four orders of magnitude more permeant than Na⁺, and that block occurs when 3 Na⁺ ions occupy a low affinity binding site (K _0.5=130±30 mM) with a dielectric coefficient of 0.23±0.03. These data support the conclusion that the ouabain-sensitive conducting pathway is a result of passive leak of both Na⁺ and H⁺ through the Na⁺/K⁺ pump.     

Prescribing Functional Additives for Treating the Poor Performances of High‐Voltage (5 V‐class) LiNi0.5Mn1.5O4/MCMB Li‐Ion Batteries

In this paper, tris(trimethylsilyl) phosphite (TMSP) and 1,3‐propanediolcyclic sulfate (PCS) are unprecedentedly prescribed as binary functional additives for treating the poor performances of high‐voltage (5 V‐class) LiNi_0.5Mn_1.5O₄/MCMB (graphitic mesocarbon microbeads) Li‐ion batteries at both room temperature and 50 °C. The high‐voltage LiNi_0.5Mn_1.5O₄/MCMB cell with binary functional additives shows a preponderant discharge capacity retention of 79.5% after 500 cycles at 0.5 C rate at room temperature. By increasing the current intensity from 0.2 to 5 C rate, the discharge capacity retention of the high‐voltage cell with binary functional additives is ≈90%, while the counterpart is only ≈55%. By characterizations, it is rationally demonstrated that the binary functional additives decompose and participate in the modification of solid–electrolyte interface layers (both electrodes), which are more conductive, protective, and resistant to electrolyte oxidative/reductive decompositions (accompanying active‐Li⁺ consuming parasitic reactions) due to synergistic effects. Specifically, the TMSP additive can stabilize LiPF₆ salt and scavenge erosive hydrofluoric acid. More encouragingly, at 50 °C, the high‐voltage cell with binary functional additives holds an ultrahigh discharge capacity retention of 79.5% after 200 cycles at 1 C rate. Moreover, a third designed self‐extinguishing flame‐retardant additive of (ethoxy)‐penta‐fluoro‐cyclo‐triphosphazene (PFPN) is introduced for reducing the flammability of the aforementioned binary functional additives containing electrolyte.     

Trace element concentration and arsenic speciation in the well water of a Taiwan area with endemic Blackfoot disease

Blackfoot disease is a peripheral vascular disease resulting in gangrene of the lower extremities. Although extensive epidemiological study has implicated high arsenic content in artesian well water in the endemic area, there is more to learn about the etiology of the disease. In this study, effort is paid on multielement determination and arsenic speciation in order to find out whether the trace element concentration pattern in well water in the Blackfoot disease endemic area is different from those of two control areas. Experimental results indicate that the concentrations of Fe, P, Na, and Ba in well water in the Blackfoot disease endemic area are found to be significantly higher than those of the controls, but they are still below the drinking water standard. The total arsenic in well water in the endemic area (671±149 ppb) is much higher than that of one normal control area of Hsin-Chu (<0.7 ppb), but is a similar level as that of other control areas of I-Lan (653±71 ppb) where no Blackfoot disease has ever been found. It was also found that the insoluble arsenic in the endemic area (21.9 ppb) is much higher than that in two control areas (≤1.8 ppb), and the concentration ratio between As(III) and As(V) species in the endemic area (2.6) is much lower than that in one of the control areas, where the total arsenic is also high (14.7). The possible connection of Blackfoot disease with trace elements, arsenic species, and possibly other as yet undefined environmental factors in the artesian well water, is discussed.     

Philosophy of environmental enrichment: Past,present, and future

The brief tenure of environmental enrichment has been influenced both directly and indirectly by the field of psychology, from the work of B.F. Skinner to that of Hal Markowitz. Research on enrichment supports the supposition that an enriched environment does indeed contribute to a captive animal’s well‐being. Critical elements of effective environmental enrichment are 1) assessing the animal’s natural history, individual history, and exhibit constraints and 2) providing species‐appropriate opportunities, i.e., the animal should have some choices within its environment. This paper presents a historic perspective of environmental enrichment, proposes a broader, more holistic approach to the enrichment of animals in captive environments, and describes a framework or process that will ensure a consistent and self‐sustaining enrichment program. Zoo Biol 20:211–226, 2001. © 2001 Wiley‐Liss, Inc.     

New dendroarchaeological evidence of water well constructions reveals advanced Early Neolithic craftsman skills

The first European settlements accompanied by crop and livestock farming occurred approximately 7500 years ago. In this agrarian society, wood was one of the most important raw materials, most notably for construction, but only a little is known about wood use and woodworking technology. Hence, archaeological wooden finds are of particular importance. Dendroarchaeological studies combine the analysis of external and internal characteristics of archaeological wood: traces of tools on the wooden surfaces and the shape of timbers provide information about woodworking techniques, the tree rings allow dendrochronological dating and provide a paleoecological archive. In 2015 and 2016, two water wells with wooden linings from the Early Neolithic Period were discovered in the Czech Republic close to the towns of Velim (Bohemia) and Uničov (Moravia). The timbers were excellently preserved under waterlogged conditions. Here, we present a dendroarchaeological study including tree-ring and woodworking analyses. Furthermore, we consider former forest species composition. Overall, 15 lumbers from both wells were successfully dated by dendrochronology. The oaks used for the wells from Velim and Uničov were felled in 5196/5195 BCE and 5093–5085 BCE, respectively. Additionally, the taxa of 1859 wooden fragments, such as charcoals, branches and chips, were wood anatomically identified. The well lining from Velim with a hollowed tree trunk is already known from other Central European locations. In contrast, the construction from Uničov is unique for this period. Until now, the advanced construction design formed by four corner posts with longitudinal grooves and inserted horizontal planks was only known several thousands years later. The Early Neolithic wells from Uničov and Velim are the oldest archaeological discoveries of wooden artefacts in the Czech Republic that have been dendrochronologically dated. The tree-ring width series extend the Czech oak tree-ring width chronology more than 300 years into the past.     

H2 oxidation in the presence of thiosulfate, by a Thermoanaerobacter strain isolated from an oil-producing well

Abstract A thermophilic rod (strain SEBR 5268), isolated from an oil-producing well, was identified as a Thermoanaerobacter strain that was phenotypically related to T. finnii . Both SEBR 5268 and T. finnii oxidized H₂ by reducing thiosulfate to sulfide using yeast extract as growth substrate. H₂ oxidation in the presence of thiosulfate was significant at the end of the exponential growth of SEBR 5268 and was maintained during the lysis phase. In the absence of thiosulfate, H₂ was inhibitory for both strains. The role of H₂ consumption by these bacteria is discussed with regard to their metabolism on organic compounds.     

Evaluation of antibacterial activity of crude protein extracts from seeds of six different medical plants against standard bacterial strains

A huge group of natural antimicrobial compounds are active against a large spectrum of bacterial strains causing infectious threat. The present study was conducted to investigate the crude extracts of antimicrobial protein and peptide efficacy from six medicinal plant seeds. Extraction was carried out in Sodium phosphate citrate buffer, and Sodium acetate buffer using different pH. Antimicrobial activities of these plants were determined by the microbiological technique using Agar well diffusion Assay. Extremely strong activity was observed in the seed extracts of Allium ascolinicum extracted in sodium phosphate citrate buffer at pH (5.8) against Proteus vulgaris, Escherichia coli and Staphylococcus aureus with zone of inhibition 17 mm, 17 mm and 15 mm and Rumex vesicarius at pH (7.6), Ammi majus at pH (6.8), Cichorium intybus at pH (7.4) and Cucumis sativus at pH (7.8) also showed better sensitivity against the bacterial strains with zone of inhibition ranges 16–10 mm and some of the strains were found to be resistant. Antibacterial activity pattern of different plant extracts prepared in sodium acetate buffer pH (6.5), among all the plant seed extracts used Foeniculum vulgare had shown good inhibition in all the bacterial strains used, with zone of inhibition ranges 11–12.5 mm, The extracts of C. intybus and C. sativus were found to be effective with zone of inhibition 11–6 mm and some of the strains were found to be resistant. Most of the strains found to have shown better sensitivity compared with the standard antibiotic Chloramphenicol (25 mcg). Our results showed that the plants used for our study are the richest source for antimicrobial proteins and peptides and they may be used for industrial extraction and isolation of antimicrobial compounds which may find a place in medicine industry as constituents of antibiotics.