Understanding Chinese online users and their visits to websites: Application of Zipf's law

Competition for consumers to visit company websites has intensified in recent years. An important indicator of website popularity (and consequent survival) is the extent to which the website can draw consumer visits vis-à-vis other websites. A majority of the current understanding on consumer visits is limited to a single website, and leaves little knowledge on the performance of one website compared with others. In tracking the Internet usage behavior of 200 individuals in Mainland China for 30 consecutive days, we applied Zipf's law to identify the divergence points separating popular websites from non-popular ones. Two measurements were used, namely, visit traffic (number) and visit engagement (time spent). We observed that 94.87% of the entire visit traffic is devoted to 15.08% of all visited websites, whereas 84.63% of engagements are on the top 6.16% visited websites. These findings suggest that few websites accounted for the bulk of online traffic and time. Further, we segmented the dataset based on two key proxy variables of user demographics, which are gender and occupation. The findings on visit traffic remained salient after considering user segments, but the findings on website engagement varied across different user segments. Our further analysis, which categorized the visited websites by their main service, revealed the type of Internet users attracted to popular websites.     

Toward a more reflective teaching practice: Revisiting excellence in teaching

Excellence in teaching has always been a demanding and absorbing concern in institutions of higher learning. Earlier studies, which are numerous, have often dealt with the measurement of teacher qualities but have largely failed to explain the phenomenon of excellence in practice. This study focused on the outstanding professional teachers’ candid revelations of their subjective experiences of becoming and being excellent in their craft. Findings of the study indicated that love is the touchstone of excellence in teaching: that is, loving the students, loving knowledge and loving the teaching process.     

Fluid and electrolyte balance in elite male football (soccer) players training in a cool environment

There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5°C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (?± s) sweat loss during training was 1.69?±?0.45 l (range 1.06?-?2.65 l). Mean fluid intake during training was 423?±?215 ml (44?-?951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r ² = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5?±?13.0 mmol?·?l^?1 and mean sweat potassium concentration was 4.2?±?1.0 mmol?·?l^?1. Total salt (NaCl) loss during training was 4.3?±?1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.     

Curative role of pantothenic acid in brain damage of gamma irradiated rats

Radiation induced brain damage is associated with impairment of mitochondrial functions, variations in the level of neurotransmitters, and oxidative stress. Mitochondrial function is closely linked to the level of neurotransmitters since the precursors are supplied by the Kreb’s cycle intermediates. The objective of this study was to evaluate the influence of pantothenic acid, an essential component in the synthesis of Coenzyme A (CoA), on the activity of the Krebs cycle enzymes, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH), and succinate dehydrogenase (SDH); the level of aspartic, glutamic and GABA; the activity of transaminases, and oxidative stress, in the cerebrum of γ-irradiated rats. Pantothenic acid (26 mg/Kg) was orally administered to the rats, 2 h after irradiation and during the following 5 days. Animals were sacrificed the 7th day post-irradiation. The exposure of male albino rats to γ-rays (5 Gy) has triggered oxidative stress notified by a significant elevation in the level of malondialdehyde (MDA), an end product of lipid peroxidation, associated to a significant decrease in the content of phospholipids, and the antioxidant compound glutathione (GSH). The activity of IDH, α-KGDH, and SDH, has significantly decreased, while the level of aspartic, glutamic and GABA has significantly increased. In parallel to these changes, the activity of alanine and aspartate transaminase has significantly increased, compared to their values in the control rats. Pantothenic acid treatment, has significantly attenuated oxidative stress; enhanced the activity of IDH, α-KGDH, and SDH; minimized the increase in the level of amino acids and the activity of transaminases, compared to their values in the cerebrum of irradiated rats. In conclusion, pantothenic acid could improve the level of neurotransmitters amino acids, which depends on the enzymatic activities of Krebs cycle and linked to oxidative stress.     

Inhibitory activities of microalgal extracts against Epstein-Barr virus DNA release from lymphoblastoid cells

This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus, Synechococcus elongatus, and Spirulina platensis against Epstein-Barr virus (EBV) in three Burkitt's lymphoma (BL) cell lines, namely Akata, B95-8, and P3HR-1. The antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction (PCR) technique. The methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in reducing cell-free EBV DNA (EC(50)<0.01 μg/ml) with a high therapeutic index (>28000). After fractionation by column chromatography, the fraction from Synechococcus elongatus (SEF1) reduced the cell-free EBV DNA most effectively (EC(50)=2.9 μg/ml, therapeutic index>69). Upon further fractionation by high performance liquid chromatography (HPLC), the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA (EC(50)=1.38 μg/ml, therapeutic index>14.5). This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.