Income inequality and environmental degradation in Egypt: evidence from dynamic ARDL approach

Environmental Science and Pollution Research - Over the past four decades, the Egyptian economy has suffered from both income inequality and environmental degradation. This dual problem raises the...     

Biomonitoring of bisphenol A, 4-nonylphenol,and 4-t-octylphenol in Turkish population: exposure and risk assessment

Environmental Science and Pollution Research - Biomonitoring studies are important tools to understand the effects of endocrine-disrupting compounds on human health. Up to now, there have been no...     

A bibliometric review on the inter-connection between climate change and rice farming

Environmental Science and Pollution Research - Rice is an important cereal and a staple food in many countries in the world. Climate change is a significant challenge that affects paddy production...     

Female tactile cues maximize paternal behavior in prairie voles

Most monogamous male mammals display parental care, but the mechanism by which they become motivated to care for infants remains unknown. We used prairie voles (Microtus ochrogaster) as a model of biparental species to test the hypothesis that physical contact with a female enhances male parental responsiveness before the birth of offspring. We tested four groups of males: mated with physical contact with their mate, mated with only distal cues from their mate, mated with no cues, and unmated with distal cues from a female. The subjects were placed in an oversized cage divided into two compartments by a perforated barrier. At mid-gestation, the bedding and females were removed, and the males’ responses toward two infants were videotaped. Although most males behaved parentally, mated males exposed to their mate’s tactile or distal cues approached the young faster and were more likely to care for both infants than unmated males which received female distal cues. Males who had physical contact with their mate showed “kyphosis” (a crouching position over infants) and contacted infants more frequently than mated males which received no cues from their mate or unmated males which received female distal cues. Furthermore, the frequency of non-social behaviors was lowest in mated males that had physical contact with their mate. The data suggest that exposure to female distal cues after mating is sufficient to increase male parental attentiveness, but female somatosensory cues affect the male's tendency to remain in physical contact with infants.     

Protective effect of Spirulina platensis against aluminium-induced nephrotoxicity and DNA damage in rats

The protective effect of Spirulina platensis (SP) powder against aluminium-induced nephrotoxicity and DNA damage in rats was studied. Male rats receiving daily 40 mg/kg b.wt. aluminium chloride (AlCl₃) orally had increased serum levels of urea and creatinine, up regulated kidney injury molecule-1 and tissue inhibitor of metalloproteinase-1 genes, down regulated catalase and glutathione peroxidase genes, and increased all parameters of kidney DNA damage using comet assay. Treatment with SP alleviated all AlCl₃-induced effects of toxicity, especially when the animals were pre-treated.     

Synthesis,extraction, and identification of light polycyclic aromatic hydrocarbons (PAH) in microwave oven fried Aseel chicken tissues

The present study was conducted to determine the effects of microwave oven frying on production of four, light polycyclic aromatic hydrocarbons (PAH) anthracene, fluorene, phenathrene, and pyrene in four tissues heart, liver, neck, and wings of Aseel chickens. The microwave oven-fried samples of tissues along with respective control after appropriate preparation were analyzed using high-performance liquid chromatography. These PAH were identified by comparing retention time of the unknown with known ones and concentration was calculated. Data showed that among the four chicken tissues, the neck contained the maximum level (0.079 mg/kg) of anthracene while wings contained the minimum (0.006 mg/kg). Similarly, in case of flourene, the fried heart showed greater percentage increase (225.04%) while wings showed 16.18% fluorene compared with other two organs, while phenanthrene and pyrene were maximal in wings at 0.249 mg/kg and 0.094 mg/kg, respectively. Results demonstrate that high-temperature treatment such as microwave oven frying of chicken meat might be responsible to generate these toxicants. Further study is to determine the production of other PAH under the different barbecuing conditions using various meat varieties.     

Characterization of Environmentally Friendly Polymers by Inverse Gas Chromatography: I Amylopectin

Amylopectin, as a potato starch based polymer, with a molecular weight of six million gram/mol was characterized using the Inverse Gas Chromatography Method (IGC). DSC method was also used to measure the glass and melting temperatures. Both DSC and IGC agreed well on a T_g of 105°C and T_m of 160–166°C. Nineteen solutes (solvents) were injected onto a chromatographic column containing amylopectin. These solutes revealed the interaction of alkanes with AP, and the wettability and water intake of AP. Alkanes showed exothermic values of interaction parameters which were increased as the temperature increased and as the number of carbons in the alkane series decreased. Retention diagrams of these solutes in a temperature range of 80–200°C revealed two zones, crystalline and amorphous. T_g and T_m were measured using these zones which complimented the DSC values. The two zones were used to calculate the degree of crystallinity below the melting temperature which ranged from 85% at 104°C to 0% at 161°C. The dispersive component of the surface energy of amylopectin was measured using alkanes which ranged from 25.35 mJ/m² at 80°C to 8.47 mJ/m² at 200°C. This is attributed to the weak crystalline surface of AP at 80°C and when the surface melted at 160°C the surface energy decreased due to the thermal expansion of the surface.     

Mineral potential and scope of investment in the Republic of Yemen

On 22 May 1990 the Yemen Arab Republic and Peoples Democratic Republic of Yemen were unified to form the Republic of Yemen, with a population of about 14 million people in an area of about 580 000 km². The Republic of Yemen is hoping to develop its mineral industry. Possessing a well established geological database plus a newly issued mining law and investment law, Yemen is inviting all investors, whether from the Yemeni private sector or foreign companies, either solely or in joint ventures to investigate opportunities in minerals and construction and industrial materials.     

Functional wildlife parks: The views of Kenyan children who live with them

This study reports on Kenyan school children's ideas about wildlife parks in their country. A comparison is made between the responses of school children in primary school, before they receive any science education, and those of secondary school pupils at the end of the secondary cycle. The findings show little difference between the two groups of students in terms of their ideas about wildlife parks. This has serious implications for science and environmental education in Kenya. Parks are understood by these pupils in terms of real life issues, as derived from social consequences. The children's ideas are all based on the role that parks play in society, but the function of parks to support biodiversity conservation does not seem to be important to the students. While it is satisfying to note that the school children have a good understanding of parks in their social context, it is essential to address fully the scientific and ecological role of parks in order that biodiversity becomes more valued in our society.     

Effect of shape of nanoparticle on heat transfer and entropy generation of nanofluid-jet impingement cooling

ABSTRACT

Al₂O₃/water nanofluid has been numerically examined for the first time with different nanoparticle shapes including, cylindrical, blade, brick, platelet and spherical, on the flat and triangular-corrugated impinging surfaces. The volume fractions of 1.0%, 2.0% and 3.0% nanoparticles have been used. The Reynolds number is between 100–500 depending on the slot diameter. The finite volume method is utilized to determine the governing equations. The study is analyzed to determine how the flow features, heat transfer features and entropy production were affected by the diversity of nanoparticle shape, nanoparticle volume fraction, and shape of impinging surface. Darcy friction factor and Nusselt number are studied in detail for different conditions. The temperature contours are presented in the case of different nanoparticle volume fractions, nanoparticle shapes and both impinging surfaces. The results of the study suggest that the nanoparticle shape of the platelet shows the highest heat transfer development due to the thinner thermal boundary layer. Heat transfer augments with increasing volume fraction of nanoparticles. In addition, the study is consistent with the results of the literature on heat transfer and flow properties.