The effect of heavy metals on some aspects of lichen physiology

1976 ◽  
Vol 54 (23) ◽  
pp. 2695-2703 ◽  
Author(s):  
K. J. Puckett
Keyword(s):  
Heavy Metals ◽  
Absorption Spectrum ◽  
Physicochemical Properties ◽  
Membrane Integrity ◽  
The Other ◽  
Short Term ◽  
Potassium Loss ◽  
Specific Concentration ◽  
Lichen Physiology ◽  
Copper Lead

The effect of the heavy metals cadmium, cobalt, copper, lead, mercury, nickel, and silver on the lichen Umbiliearia muhlenbergii (Ach.) Tuck, is described in terms of membrane integrity, chlorophyll damage, and changes in photosynthetic 14C fixation. Increasing concentrations of copper, mercury, and silver produced a gradual potassium loss from the thallus while the other metals tested initiated an abrupt efflux at a specific concentration. Copper, mercury, and silver caused both a displacement and a decrease in the absorption spectrum of chlorophyll, whereas no detectable changes were induced by the other metals. The relative toxicities of these metals on photosynthesis is reflected in the series Ag. Hg > Co > Cu, Cd > Pb, Ni for short-term exposures, and Ag. [Formula: see text] for extended exposures. The tendency for the metals studied to fall into two distinct groups on the basis of their effects on lichen metabolism is discussed in terms of their physicochemical properties.

scholarly journals EFFECTS OF GAS FLARING ON THE MICROBIAL AND PHYSICOCHEMICAL PROPERTIES OF SOILS IN DELTA STATE

2021 ◽  
pp. e309
Author(s):  
Joseph Enuenwemba ◽  
Nduka Uraih ◽  
William Tanimowo ◽  
Hilda Emmanuel-Akerele
Keyword(s):  
Heavy Metals ◽  
Local Government ◽  
Physicochemical Properties ◽  
Ph Value ◽  
Soil Samples ◽  
Local Government Area ◽  
The Other ◽  
Gas Flaring ◽  
Significant Difference ◽  
The Impact

This study was carried out to determine the impact of gas flaring on microbial and physicochemical characteristics of soil around Ebedei and Kwale Flow Stations in Delta State, Nigeria. Soil samples were collected around Ebedei, in Ukwuani local government area, and Kwale, in Ndokwe West local government area both in Delta State, as well as in their environs. While the soil samples were collected for the analysis of physical, chemical and biological properties of the soil. The highest concentration of the heavy metals was obtained at 10m away from the flaring sites (P < 0.05). In both Ebedei and Kwale, the Fe concentration is significantly higher (1080.33 and 1080.68 mg/kg, respectively) that the other two heavy metals. However, there was a significant difference in the concentration of Zn between Ebedei and Kwale (P < 0.05). In both Ebedei and Kwale, the ECEC concentration is significantly higher (8.16 and 6.57 meq/100g, respectively) that the other chemical parameters. The physicochemical properties were similar at the different distances away from gas flaring sites (P> 0.05). EC decreased from 119.12µs/cm (at 10m) to 50.4 (at 100m) and then to 44.37 (at 200m). pH value remained acidic ranging from 4.97 (at 10m) to 5.9 (at 200m); moisture content ranged from 3.25% (at 10m) to 5.89% (at 200m); organic matter ranged from 1.07% (at 10m) to 1.61 % (at 200m); NO3 reduced sharply from 10.35 mg/kg (at 10m) to 3.92mg/kg (at 100m) and then to 2.4mg/kg (at 200m); phosphate dropped from 0.91mg/kg at (at 10m) to 0.95mg/kg (at 100m) to 0.42mg/kg (at 200m). There was a significant difference in the amount of some physicochemical properties in the soil samples collected from the gas flaring areas in Ebedei and Kwale (P<0.05). Ebedei, Kwale and environs constitute part of the most vegetative and productive areas of the Niger Delta region, these areas are also rich in several pharmacological properties and water resources. The Government should ensure the enforcement of laws aimed at minimizing the amount of gas flared into the atmosphere. Urgent efforts should be geared at cushioning the effect of gas flaring on the communities affected, probably by compensating them or, by relocating them to a more environmental friendly settlement with compensations.

A Bird in the Hand Isn’t Good for Long

2018 ◽  
Vol 65 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Stefan Scherbaum ◽  
Simon Frisch ◽  
Maja Dshemuchadse
Keyword(s):  
Decision Making ◽  
Cognitive Control ◽  
The Other ◽  
Decision Task ◽  
Short Term ◽  
Additional Time ◽  
Control Processes ◽  
Folk Wisdom ◽  
Study Participants ◽  
Insight Into

Abstract. Folk wisdom tells us that additional time to make a decision helps us to refrain from the first impulse to take the bird in the hand. However, the question why the time to decide plays an important role is still unanswered. Here we distinguish two explanations, one based on a bias in value accumulation that has to be overcome with time, the other based on cognitive control processes that need time to set in. In an intertemporal decision task, we use mouse tracking to study participants’ responses to options’ values and delays which were presented sequentially. We find that the information about options’ delays does indeed lead to an immediate bias that is controlled afterwards, matching the prediction of control processes needed to counter initial impulses. Hence, by using a dynamic measure, we provide insight into the processes underlying short-term oriented choices in intertemporal decision making.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

Pengembangan Kemitraan Koperasi, Usaha Mikro Dan Kecil (KUMK) Dengan Usaha Menengah/Besar Untuk Komoditi Unggulan Lokal

2019 ◽  
Vol 9 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Dandan Irawan
Keyword(s):  
Business Performance ◽  
The Other ◽  
Economic Conditions ◽  
Small Enterprises ◽  
Business Partnerships ◽  
Short Term ◽  
Business Partnership ◽  
Structure Factors ◽  
Micro And Small Enterprises ◽  
Business Entities

Basically a natural partnership will achieve its goal if mutual requirements, mutual reinforcement, and mutual benefit can be maintained and made a strong fundamental commitment among partners. Nevertheless the development seems very slow. The cause is the presence of specific and different conditions and structure factors compared to other countries. Along with that, we still encounter various forms of gaps, such as inequality among regions, among income groups, between sectors, among economic actors, and so forth. The next problem is that in business entities including cooperatives and micro and small enterprises in running their business activities requires business partnerships with medium and large enterprises in order to improve business performance and business scale. While on the other hand our economic conditions and structures are not yet fully conducive to fostering partnerships based on purely business considerations or competitive market motivations but the business partnership of the foundation is strong enough in our country's constitution. Partnerships will work if partners are equally benefiting. Our concept of partnership is like that, although in the short term, there is a party or a party benefiting more from the other side.

EFFECT OF ACTINOMYCIN D ON TSH-INDUCED STIMULATION OF THYROIDAL PROTEIN SYNTHESIS IN THE RAT

1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar
Keyword(s):  
Protein Synthesis ◽  
Actinomycin D ◽  
The Other ◽  
Leucine Incorporation ◽  
Short Term ◽  
Other Hand ◽  
Thyroid Glands ◽  
Translational Level ◽  
Stimulation Of

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

scholarly journals Innovative Ultrasound-Assisted Approaches towards Reduction of Heavy Metals and Iodine in Macroalgal Biomass

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 649
Author(s):  
Estefanía Noriega-Fernández ◽  
Izumi Sone ◽  
Leire Astráin-Redín ◽  
Leena Prabhu ◽  
Morten Sivertsvik ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Dry Weight ◽  
The Other ◽  
Laminaria Hyperborea ◽  
Other Hand ◽  
Macroalgal Biomass ◽  
Ultrasound Assisted ◽  
I 31

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of Laminaria hyperborea. Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg−1 of dry weight, respectively, were found in L. hyperborea blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in L. hyperborea, thus improving the product’s safety for consumers.

scholarly journals Influence of Physicochemical Properties and Parent Material on Chromium Fractionation in Soils

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1073
Author(s):  
Claudia Campillo-Cora ◽  
Laura Rodríguez-González ◽  
Manuel Arias-Estévez ◽  
David Fernández-Calviño ◽  
Diego Soto-Gómez
Keyword(s):  
Physicochemical Properties ◽  
Contaminated Soils ◽  
Research Work ◽  
Parent Material ◽  
The Other ◽  
Oxidation States ◽  
Diethylenetriaminepentaacetic Acid ◽  
Remediation Strategies ◽  
Exchangeable Aluminum ◽  
Efficient Extraction

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.

scholarly journals Prediction of Head Movement in 360-Degree Videos Using Attention Model

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3678
Author(s):  
Dongwon Lee ◽  
Minji Choi ◽  
Joohyun Lee
Keyword(s):  
Machine Learning ◽  
Short Term Memory ◽  
Moving Average ◽  
The Other ◽  
Learning Models ◽  
Short Term ◽  
Term Memory ◽  
Attention Model ◽  
Long Short Term Memory ◽  
Machine Learning Models

In this paper, we propose a prediction algorithm, the combination of Long Short-Term Memory (LSTM) and attention model, based on machine learning models to predict the vision coordinates when watching 360-degree videos in a Virtual Reality (VR) or Augmented Reality (AR) system. Predicting the vision coordinates while video streaming is important when the network condition is degraded. However, the traditional prediction models such as Moving Average (MA) and Autoregression Moving Average (ARMA) are linear so they cannot consider the nonlinear relationship. Therefore, machine learning models based on deep learning are recently used for nonlinear predictions. We use the Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) neural network methods, originated in Recurrent Neural Networks (RNN), and predict the head position in the 360-degree videos. Therefore, we adopt the attention model to LSTM to make more accurate results. We also compare the performance of the proposed model with the other machine learning models such as Multi-Layer Perceptron (MLP) and RNN using the root mean squared error (RMSE) of predicted and real coordinates. We demonstrate that our model can predict the vision coordinates more accurately than the other models in various videos.

scholarly journals Li-Nafion Membrane Plasticised with Ethylene Carbonate/Sulfolane: Influence of Mixing Temperature on the Physicochemical Properties

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1150
Author(s):  
Aigul S. Istomina ◽  
Tatyana V. Yaroslavtseva ◽  
Olga G. Reznitskikh ◽  
Ruslan R. Kayumov ◽  
Lyubov V. Shmygleva ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Ethylene Carbonate ◽  
Membrane Integrity ◽  
Amorphous Structure ◽  
Nafion Membrane ◽  
Polymer Gel ◽  
Scanning Calorimetry ◽  
Practical Applications ◽  
Heating And Cooling ◽  
Solvent Uptake

The use of dipolar aprotic solvents to swell lithiated Nafion ionomer membranes simultaneously serving as electrolyte and separator is of great interest for lithium battery applications. This work attempts to gain an insight into the physicochemical nature of a Li-Nafion ionomer material whose phase-separated nanostructure has been enhanced with a binary plasticiser comprising non-volatile high-boiling ethylene carbonate (EC) and sulfolane (SL). Gravimetric studies evaluating the influence both of mixing temperature (25 to 80 °C) and plasticiser composition (EC/SL ratio) on the solvent uptake of Li-Nafion revealed a hysteresis between heating and cooling modes. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) revealed that the saturation of a Nafion membrane with such a plasticiser led to a re-organisation of its amorphous structure, with crystalline regions remaining practically unchanged. Regardless of mixing temperature, the preservation of crystallites upon swelling is critical due to ionomer crosslinking provided by crystalline regions, which ensures membrane integrity even at very high solvent uptake (≈200% at a mixing temperature of 80 °C). The physicochemical properties of a swollen membrane have much in common with those of a chemically crosslinked polymer gel. The conductivity of ≈10−4 S cm−1 demonstrated by Li-Nafion membranes saturated with EC/SL at room temperature is promising for various practical applications.

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