A self-phase modulated oscillator and some implications

A self-phase modulated sinewave oscillator is proved to perform as a periodic function generator. The system is investigated comprehensively and is shown to be capable of generating a variety of non-sinusoidal waveforms. The change from the generation of one waveform to the generation of another is attained by the variation of a relatively simple function in a skeletal model which does not change.     

Risk factors for adolescent substance abuse

Reviews research on risk factors for adolescent substance use disorders (SUD) and discusses possible relationships between SUDs and learning disabilities (LD). Individual level factors (genetic, biologic, other familial, and psychiatric) emerge as very important in the risk equation, as well as the interaction between individual risk and environmental conditions. Commonalities between SUD risk and LD include prenatal substance exposure, family history of SUD, conduct disorder, social skills deficits, and academic failure; however, further research is needed to establish whether individuals with LD face a specific risk for SUDs, and if so, what the nature of that risk might be.     

Impact of iodine deficiency on thyroid function in pregnant African women — A possible factor in the genesis of ‘small for dates’ babies

The effect of iodine deficiency (ID) on thyroid function in African women during pregnancy and postnatal period was examined, for which very limited information is available. Serum T₄, T₃, TSH, TBG, thyroxine binding capacity (TBK), free thyroxine index (FT₄I=T₄/TBK) and T₄/TBG were determined by ELISA technique in 32 pregnant women (resident of Plateau state, Nigeria- an ID zone) through pregnancy upto term delivery, and in 5 women up to 6 weeks post delivery. Urinary iodide level was measured at delivery to determine the degree of iodine deficiency. Results were matched with a non pregnant control comprising 44 subjects. 5555 birth weights (BW) of term babies in the region were analysed to determine the prevalence of ‘small for dates’ (SFD) babies in the population. Results show that the level of serum FT₄I was elevated very significantly at late gestation (P<.001) but the women were not hyperthyroid, suggesting a marked disturbance in binding of T₄ with TBG during pregnancy. Five women with SFD babies were found in ‘compensated hypothyroid state’ and showed a significant depression (p<.01) in serum T₄/TBG, T₄, FT₄I and T₃ levels to a low normal range, with a concurrent significant rise (p.<.001) in TSH level (above normal range) throughout pregnancy. Incidence of SFD babies was higher (p.<.001) in ID zone (Bassa 15.2%) compared to control zone (Jos 9.8%). It is concluded that a state of maternal ‘subclinical (compensated) hypothyroidism’ during pregnancy possibly plays an important role in the aetiopathogenesis of SFD babies in Africans. A normal reference range for thyroid parameters at various stages of pregnancy in healthy African women is established for the first time.     

A comparative study of the application of IT in China and the West: Culture and the stages of growth model

A comparison is made between the application of computers and other information technology (IT) in China and the West. Computers started being applied much later in developing countries. China, the largest developing country, geographically, in the world has a wish to catch up with the advanced countries and to build its own information technology infrastructure. Much of the technology, theory, and application methods have been introduced into China from the West and other countries over the past 15 years. There is a problem in that a large proportion of the technology and methods cannot simply be transferred between the West and China. On the one hand Chinese people become suspicious of the results of introducing IT from the West, and on the other hand China is a mysterious country for many western people. What has happened when IT has been introduced to China? Will there be a similar growth pattern for China as in the West? This paper compares the environment in terms of culture and the stages of growth model in an attempt to answer those questions, and improve understanding.     

Alleviation of Dimethylnitrosamine-Induced Liver Injury and Fibrosis by Supplementation of Anabasis articulata Extract in Rats

Anabasis articulata (Forssk) Moq. (Chenopodiaceae) is an herb, grows in Egypt, and used in folk medicine to treat diabetes, fever, and kidney infections. The protective and therapeutic effects of the ethanol extract of A. articulata aerial parts were evaluated against dimethylnitrosamine (DMN)-induced liver fibrosis, compared with the standard drug, silymarin. Hepatic hydroxyproline content, serum transforming growth factor-β1 (TGF-β1), interleukin 10 (IL-10) and fructosamine were measured as liver fibrosis markers. Hepatic malondialdehyde (MDA), nitric oxide (NO), catalase (CAT), glutathione reductase (GR) and glutathione content (GSH) were measured as oxidant/antioxidant markers. Parallel histopathological investigations were also performed. Protective and therapeutic administration of A. articulata (100 mg/kg daily for 4 weeks), markedly prevented DMN-induced loss in body and liver weights. The extract significantly inhibited the elevation of hepatic hydroxyproline, NO and MDA (P < 0.05), as well as serum fructosamine, and TGF-β1 (P < 0.05) induced by DMN while it restored IL-10 to normal level in both protective and therapeutic groups. Furthermore, A. articulata prevented the depletion in CAT, GR, and GSH levels (P ≤ 0.05). In addition, oral administration of A. articulata extract and silymarin to both protective and therapeutic groups reduced the increase in liver function enzyme activities; alanine and aspartate amintransferases, gamma-glutamyl transferase in addition to alkaline phosphatase, and caused significant increase in serum albumin concentration as compared to DMN group. These data corresponded closely with those obtained for the drug silymarin. Histopathological studies confirmed the biochemical data and revealed remarkable improvement in liver architecture. Thus, it could be concluded that, A. articulata extract exhibited in vivo hepatoprotective and therapeutic effects against DMN-induced liver injury and may act as a useful agent in controlling the progression of hepatic fibrosis through reduction of oxidative stress and improving liver function.     

Examining the moderating effect of inconsistent reviews and its gender differences on consumers’ online shopping decision

The prevalence of social media has provided consumers with many opportunities to post online reviews on a wide range of products on the Internet. In this study, we attempt to investigate the moderating effect of inconsistent reviews (i.e., a mix of positive and negative reviews) on consumers’ purchase decision. We further examine whether the effect will differ from female to male consumers.     

香港大学学术库——机构知识库的应用扩展

香港大学学术库是香港大学的机构知识库,是响应大学知识交流政策而建立的知识管理系统。凭借丰富的数据来源以及合理的设计机制,学术库已成为颇具影响力的香港大学人才和科研成果的展示平台,成为校内外学术交流的中心,为学术评估和声誉管理提供了基础。     

The microfluidics of the eccrine sweat gland,including biomarker partitioning,transport, and biosensing implications

Non-invasive and accurate access of biomarkers remains a holy grail of the biomedical community. Human eccrine sweat is a surprisingly biomarker-rich fluid which is gaining increasing attention. This is especially true in applications of continuous bio-monitoring where other biofluids prove more challenging, if not impossible. However, much confusion on the topic exists as the microfluidics of the eccrine sweat gland has never been comprehensively presented and models of biomarker partitioning into sweat are either underdeveloped and/or highly scattered across literature. Reported here are microfluidic models for eccrine sweat generation and flow which are coupled with review of blood-to-sweat biomarker partition pathways, therefore providing insights such as how biomarker concentration changes with sweat flow rate. Additionally, it is shown that both flow rate and biomarker diffusion determine the effective sampling rate of biomarkers at the skin surface (chronological resolution). The discussion covers a broad class of biomarkers including ions (Na⁺, Cl⁻, K⁺, NH₄⁺), small molecules (ethanol, cortisol, urea, and lactate), and even peptides or small proteins (neuropeptides and cytokines). The models are not meant to be exhaustive for all biomarkers, yet collectively serve as a foundational guide for further development of sweat-based diagnostics and for those beginning exploration of new biomarker opportunities in sweat.     

Still Playing Together(?): A Recall to Physical Education and Sport History Intersections

As academic disciplines, Physical Education and Sport History share interests in performance, participation, physique and the politics of corporeal praxis. Engendering unity between the two disciplines, however, has not been without concern. Scholars working within (and across) both fields have highlighted how the potential for shared knowledge production and meaning making has been, to a degree, stymied by epistemological and methodological criticism and trepidation. Issues over contextualization, rigour, narrative schemas, conceptualizations of the body, and notions of agency and power still, in particular, constrain our current educational and historical readings and renderings of physical culture(s). Scholarly schisms and methodological differences can be overcome, however, and need not prohibit disciplinary collaborations that might better address prevailing ethical questions and affect political cause; vis-à-vis the body, the physical and sport. This brief piece is, consequently, recourse to the scholarly symbiosis between Physical Education and Sport History and echoes the encouragement of our earlier colleagues to play, inquire, create and produce together.