Estrogen Receptors Mediated Negative Effects of Estrogens and Xenoestrogens in Teleost Fishes—Review

Estrogen receptors (ERs) play a key role in many biochemical and physiological processes, that are involved in maintaining organism homeostasis. At the most basic level, they can be divided into nuclear estrogen receptors and membrane estrogen receptors that imply their effect in two ways: slower genomic, and faster non-genomic. In these ways, estrogens and xenoestrogens can negatively affect animal health and welfare. Most of the available literature focuses on human and mammalian physiology, and clearly, we can observe a need for further research focusing on complex mutual interactions between different estrogens and xenoestrogens in aquatic animals, primarily fishes. Understanding the mechanisms of action of estrogenic compounds on the ERs in fishes and their negative consequences, may improve efforts in environmental protection of these animals and their environment and benefit society in return. In this review, we have summarized the ER-mediated effects of xenoestrogens and estrogens on teleost fishes metabolism, their carcinogenic potential, immune, circulatory, and reproductive systems.     

On nanotube carbon deposition at equilibrium in catalytic partial oxidation of selected hydrocarbon fuels

Computations of thermodynamic equilibrium conditions for depositing carbon in various crystallographic forms are carried out for C-H-O reformates from methane and LPG. Selected examples of reactions accompanying oxidation or thermal decomposition of C₁ to C₄ hydrocarbons are presented, followed by theoretical fundamentals for chemical equilibrium. Table values of the standard chemical potential of the reactants are cited along with respective reaction equilibrium constants. Thermodynamic critical conditions for deposition of several carbon allotropes from gaseous reformates originated from partial oxidation with either air or pure oxygen are also quantified. Computation results are presented graphically in terms of the oxygen-to-carbon ratio, O/C, against temperature for varied pressure and oxidant. Zones of either carbon deposition or carbon-free are specified for graphite or one of the two carbon nanotubes, CNTs. The maximum effect of increase in the critical O/C for a CNT against pure graphite is estimated at 85%.     

Optimization of Settling Behavior for an Efficient Solvent‐Extraction Process for Biobased Components

Extraction is a downstream process option in biobased processes. Because knowledge of phase‐separation behavior is essential for designing efficient separation processes, this study investigates the settling and coalescence behavior of biobased extraction systems by using a standard laboratory‐scale settling cell. The influence of different buffer media and Escherichia coli cells on coalescence was determined for the reactive extraction of hexane‐1,6‐diamine with isostearic acid and di(2‐ethylhexyl)phosphoric acid by using kerosene and oleyl alcohol as diluents. As a result, an increasing pH value of the buffer significantly increases the settling time. The presence of E. coli cells hinders phase separation of the investigated systems, in particular, with dispersed organic phases.     

An adaptive RAM-DFE for storage channels

A modification of the decision feedback equalizer (DFE), RAM-DFE, is presented and analyzed for use in channels with trailing nonlinear intersymbol interference, especially binary saturation-recording channels. In the RAM-DFE, a look-up table, which can be easily implemented with random access memory, (RAM), replaces the transversal filter feedback section of the DFE. The feedforward section of the equalizer remains linear. A general nonlinear Markov (or finite-state machine) model is used to model the nonlinear intersymbol interference (ISI) channel. With this Markov model, a method is introduced for computing the minimum-mean-squared-error settings of the feedforward filter coefficients and the feedback filter and look-up table contents for the linear DFE and the RAM-DFE, respectively. RAM-DFE with these settings can be significantly better than the linear DFE for channels with trailing nonlinear ISI. Globally convergent gradient-type algorithms for updating the feedforward section coefficients and the contents of the feedback table are introduced and analyzed. Results based on data taken from disk storage units are discussed     

Finding locations for public service centres that compete with private centres: Effects of congestion

We propose a locational model for public service centres when they compete with private centres. Customers may be captured by the centre offering shorter distance or lower waiting times. Both types of centres provide paid services to high-income customers, and public centres also provide subsidised services to low-income customers. Equilibrium must be found in public centres between low-income population coverage and high-income population capture. We analyse the effects of waiting times on the design of the public service and apply the model to data for Santiago, Chile.Received: 8 February 2003, Accepted: 9 September 2003, JEL Classification: C61, I18, L33This research has been partly funded by FONDECYT (Chilean Science and Technology Research Fund) Project Nr. 1020778.     

Dietary diversity and associated factors among beneficiaries of 77 child care centers: Central Regional,Venezuela

The aim of this study was to estimate household measure diet quality, using a dietary diversity score, and its associated demographic and socio-economic factors. One hundred fifty three households representatives of the Capital District and Miranda State belonging of seventy seven day care children centers were studied. To gather data on dietary diversity, we used the food register method, collecting data on household food availability during a month. Dietary diversity at day care centers of the Capital District was 46 foods differed from that found, in Miranda State was 39 foods (p = 0.005). Likewise it differed in beneficiaries' households of the Capital District was 33 foods compared to those in Miranda State was 25 foods (p = 0.000). There were 13 and 14 foods more between day care centers and the households in both states. State (Capital District or Miranda), money spent on food per person, households size and social level were variables that explained 28.9% of dietary diversity variation in households studied. Households in the Capital District had less members, spent more money on food, and a greater proportion were non-poor compared to those in Miranda. These factors could partially explain differences in diet quality among households in the two States. Whatever perspective studied indicates that the dietary diversity had a statistically significant difference between day care centers and households in states studied. Miranda State was more deficiency than Capital District. Higher dietary diversity reflects a better quality diet at day care centers compared to households studied.     

Sequence Features of Drosha and Dicer Cleavage Sites Affect the Complexity of IsomiRs

The deep-sequencing of small RNAs has revealed that different numbers and proportions of miRNA variants called isomiRs are formed from single miRNA genes and that this effect is attributable mainly to imprecise cleavage by Drosha and Dicer. Factors that influence the degree of cleavage precision of Drosha and Dicer are under investigation, and their identification may improve our understanding of the mechanisms by which cells modulate the regulatory potential of miRNAs. In this study, we focused on the sequences and structural determinants of Drosha and Dicer cleavage sites, which may explain the generation of homogeneous miRNAs (in which a single isomiR strongly predominates) as well as the generation of heterogeneous miRNAs. Using deep-sequencing data for small RNAs, we demonstrate that the generation of homogeneous miRNAs requires more sequence constraints at the cleavage sites than the formation of heterogeneous miRNAs. Additionally, our results indicate that specific Drosha cleavage sites have more sequence determinants in miRNA precursors than specific cleavage sites for Dicer and that secondary structural motifs in the miRNA precursors influence the precision of Dicer cleavage. Together, we present the sequence and structural features of Drosha and Dicer cleavage sites that influence the heterogeneity of the released miRNAs.     

An effect of suint on sheep wool impedance and heat resistance values

ABSTRACT

The phenomenon of impedance finds an application in many areas of science; however, no studies relate to wool. Thus, the aim of the study was an examination of an effect of from the presence of suint layer on sheep wool fibers on impedance and heat resistance values. Electrical characteristics (impedance [Ω]) and heat resistance were compared in terms of wool washing effect. The impedance of wool samples was tested in the frequency range of 10 Hz to 1 MHz. In order to measure electrical characteristics and heat resistance values, five samples of greasy wool were collected from different sheep breeds, standardized by weight. After the analyses, the samples were washed and reexamined. The results showed significant differences in the impedance between the greasy and washed wool samples in each of the tested breed (p > 0.05). The suint layer reduces the impedance level, which was also confirmed by a heat resistance test results demonstrating that absence of suint layer on wool fibers significantly reduced this feature value (p > 0.05). This was also reflected in the weight differences between the examined wool samples before and after their washing.     

Broad-band frequency characterization of double Y-branch nanojunction operating as room-temperature RF to DC rectifier

Room-temperature dc and broad-band high-frequency (HF) to dc conversion measurements of a double Y-branch junction (YBJ) are presented and discussed. Nonlinear dc characteristics of the devices at room temperature are observed and HF to dc conversion up to 40 GHz at room temperature is presented. The HF to dc conversion efficiency degradation is found to be partly due to losses in interconnects feeding the device. A small-signal equivalent circuit of the YBJ is proposed in order to verify the frequency dependence of intrinsic elements.