Heterogeneous mobile phone ownership and usage patterns in Kenya

The rapid adoption of mobile phone technologies in Africa is offering exciting opportunities for engaging with high-risk populations through mHealth programs, and the vast volumes of behavioral data being generated as people use their phones provide valuable data about human behavioral dynamics in these regions. Taking advantage of these opportunities requires an understanding of the penetration of mobile phones and phone usage patterns across the continent, but very little is known about the social and geographical heterogeneities in mobile phone ownership among African populations. Here, we analyze a survey of mobile phone ownership and usage across Kenya in 2009 and show that distinct regional, gender-related, and socioeconomic variations exist, with particularly low ownership among rural communities and poor people. We also examine patterns of phone sharing and highlight the contrasting relationships between ownership and sharing in different parts of the country. This heterogeneous penetration of mobile phones has important implications for the use of mobile technologies as a source of population data and as a public health tool in sub-Saharan Africa.     

Mobile phone usage and male infertility in Wistar rats

A significant decrease in protein kinase C and total sperm count along with increased apoptosis were observed in male Wistar rats exposed to mobile phone frequencies (2 h/day x 35 days at 0.9 W/kg specific absorption rate). The results suggest that a reduction in protein kinase activity may be related to overproduction of reactive oxygen species (ROS) under microwave field exposure. Decrease in sperm count and an increase in apoptosis may be causative factor due to mobile radiation exposure leading to infertility.     

Effects of intensive and moderate cellular phone use on hearing function

The purpose of this study is to investigate the effects of radiation emitted by mobile phones on the hearing of users. The study was carried out on three groups: 1) 20 men who have used a cellular phone frequently and spoken approximately 2 h per day for four years; 2) 20 men who have used a cellular phone for 10-20 min per day for four years; and 3) 20 healthy men who have never used a cellular phone (the control group). Brainstem evoked response audiometric (BERA) and pure tone audiometric (PTA) methods were used to measure the effects of exposure on hearing function of the subjects. In BERA measurements, I-III, III-V, and I-V interpeak latencies were evaluated. Interpeak latency of subjects in two experimental groups was compared to that of subjects in the control group. The BERA results showed no differences among the groups (p > 0.05). In PTA measurements, detection thresholds at 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz frequencies were measured in all three groups. No differences were observed between moderate mobile phone users (10-20 min. per day) and control subjects. However, detection thresholds in those who talked approximately 2 h per day were found to be higher than those in either moderate users or control subjects. Differences at 4000 Hz for both bone and air conduction for right ears, and 500 Hz, and 4000 Hz bone and air conduction for left ears were significant for mean hearing threshold. This study shows that a higher degree of hearing loss is associated with long-term exposure to electromagnetic (EM) field generated by cellular phones.     

A new concept for medical imaging centered on cellular phone technology

According to World Health Organization reports, some three quarters of the world population does not have access to medical imaging. In addition, in developing countries over 50% of medical equipment that is available is not being used because it is too sophisticated or in disrepair or because the health personnel are not trained to use it. The goal of this study is to introduce and demonstrate the feasibility of a new concept in medical imaging that is centered on cellular phone technology and which may provide a solution to medical imaging in underserved areas. The new system replaces the conventional stand-alone medical imaging device with a new medical imaging system made of two independent components connected through cellular phone technology. The independent units are: a) a data acquisition device (DAD) at a remote patient site that is simple, with limited controls and no image display capability and b) an advanced image reconstruction and hardware control multiserver unit at a central site. The cellular phone technology transmits unprocessed raw data from the patient site DAD and receives and displays the processed image from the central site. (This is different from conventional telemedicine where the image reconstruction and control is at the patient site and telecommunication is used to transmit processed images from the patient site). The primary goal of this study is to demonstrate that the cellular phone technology can function in the proposed mode. The feasibility of the concept is demonstrated using a new frequency division multiplexing electrical impedance tomography system, which we have developed for dynamic medical imaging, as the medical imaging modality. The system is used to image through a cellular phone a simulation of breast cancer tumors in a medical imaging diagnostic mode and to image minimally invasive tissue ablation with irreversible electroporation in a medical imaging interventional mode.     

The influence of microwave radiation from cellular phone on fetal rat brain

The increasing use of cellular phones in our society has brought focus on the potential detrimental effects to human health by microwave radiation. The aim of our study was to evaluate the intensity of oxidative stress and the level of neurotransmitters in the brains of fetal rats chronically exposed to cellular phones. The experiment was performed on pregnant rats exposed to different intensities of microwave radiation from cellular phones. Thirty-two pregnant rats were randomly divided into four groups: CG, GL, GM, and GH. CG accepted no microwave radiation, GL group radiated 10 min each time, GM group radiated 30 min, and GH group radiated 60 min. The 3 experimental groups were radiated 3 times a day from the first pregnant day for consecutively 20 days, and on the 21st day, the fetal rats were taken and then the contents of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), noradrenaline (NE), dopamine (DA), and 5-hydroxyindole acetic acid (5-HT) in the brain were assayed. Compared with CG, there were significant differences (P<0.05) found in the contents of SOD, GSH-Px, and MDA in GM and GH; the contents of SOD and GSH-Px decreased and the content of MDA increased. The significant content differences of NE and DA were found in fetal rat brains in GL and GH groups, with the GL group increased and the GH group decreased. Through this study, we concluded that receiving a certain period of microwave radiation from cellular phones during pregnancy has certain harm on fetal rat brains.     

Dosimetric assessment of an exposure system for simulating GSM and WCDMA mobile phone usage

An exposure system for investigation of volunteers during simulated GSM and WCDMA mobile phone usage has been designed. The apparatus consists of a dual band antenna with enhanced carrying properties that enables exposure for at least 8 h a day. For GSM a 900 MHz pulse modulated carrier was used. The QPSK modulated WCDMA signal at 1966 MHz comprises a power control scheme, which was designed for investigations of biological effects. The dosimetry of the exposure system by measurements and calculations is described in detail within this paper. It is shown that the SAR distribution of the antenna shows similar characteristics to mobile phones with an integrated antenna. The 10 g averaged localized SAR, normalized to an antenna input power of 1 W and measured in the flat phantom area of the SAM phantom, amounts to 7.82 mW/g (900 MHz) and 10.98 mW/g (1966 MHz). The simulated SAR(10 g) in the Visible Human head model agrees with measured values to within 20%. A variation of the antenna rotation angle results in an SAR(10 g) change below 17%. The increase of the antenna distance by 2 mm with respect to the human head leads to an SAR(10 g) change of 9%.     

Survey of six bee viruses using RT-PCR in Northern Thailand

Six honey bee viruses were surveyed using RT-PCR in Northern Thailand where about 80% of Thai apiaries are located. Tested samples were found to be positive for deformed wing virus (DWV), acute bee paralysis virus (ABPV), sacbrood virus (SBV) and Kashmir bee virus (KBV). In the collected samples, neither chronic bee paralysis virus nor black queen cell virus nucleic acids could be detected. It was found that DWV was the most widespread and ABPV was the second most prevalent. Kashmir bee virus was found only in the Lampang province where high infestation of Varroa destructor mite occurred. Tropilaelaps, European foulbrood, and Chalkbrood diseases were found in some apiaries.     

Survey of aflatoxin-producing fungi in certain fermented foods and beverages in Thailand

Aflatoxin-producing fungi were found in fermented foods and beverages: fermented rice (kaomak), soybean sauce (taotjo), peanut butter, soy sauce (shoyu), Thai red and white wine, and rice sugar wine. These foods were extracted directly and tested for aflatoxins by thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC).Four strains of aflatoxin-producing fungi were isolated from peanut butter, taotjo, and shoyu. Direct extracts of 10% of the peanut butters tested and 5% of the kaomak tested contained large amounts of aflatoxins. The HPLC procedure used in this experiment utilized chloroform-ethyl acetate (31)     

Estimation of relative exposure levels for cellular phone users using a neural network

The wide and growing use of cellular phones has raised questions about the possible health risks associated with radio frequency (RF) electromagnetic fields. It would be helpful for epidemiologists as well as cellular phone users to obtain the relative exposure levels, because the RF exposure level is very difficult to accurately measure and quantify for all individuals. In this study, a neural network model was developed to estimate relative exposure levels on a scale of 0-10 and thus rank the individual risk of exposure using available information. We used parameters such as usage time per day, total usage period, hands-free usage, extension of antenna, specific absorption rate (SAR) of the cellular phone, and flip or folder type, which are related to RF exposure. Using the relative exposure levels obtained from this model, epidemiologists can divide the subjects into exposed and nonexposed groups in a study investigating the relationship between exposure level and brain cancer in the future, provided that more knowledge between the cellular phone usage pattern and the exposure is available.     

大学生生态意识调查研究

本文对河南省部分高校在校大学生的生态意识进行了问卷调查,通过对结果的统计和分析,掌握了大学生生态意识现状,大学生中的大多数能认识到生态环境保护的重要性、必要性和紧迫性,但其认识水平和相应生态学知识并未达到我国可持续发展战略实施的要求,大学生要求面向全校开设生态学课。在调查和分析的基础上,本文认为有必要在大学生中加强生态学基础知识的普及。     

Enhanced cellular receptor usage by a bioselected variant of coxsackievirus a21

Decay-accelerating factor (DAF) functions as cell attachment receptor for a wide range of human enteroviruses. The Kuykendall prototype strain of coxsackievirus A21 (CVA21) attaches to DAF but requires interactions with intercellular cell adhesion molecule 1 (ICAM-1) to infect cells. We show here that a bioselected variant of CVA21 (CVA21-DAFv) generated by multiple passages in DAF-expressing, ICAM-1-negative rhabdomyosarcoma (RD) cells acquired the capacity to induce rapid and complete lysis of ICAM-1-deficient cells while retaining the capacity to bind ICAM-1. CVA21-DAFv binding to DAF on RD cells mediated lytic infection and was inhibited by either antibody blockade with a specific anti-DAF SCR1 monoclonal antibody (MAb) or soluble human DAF. Despite being bioselected in RD cells, CVA21-DAFv was able to lytically infect an additional ICAM-1-negative cancer cell line via DAF interactions alone. The finding that radiolabeled CVA21-DAFv virions are less readily eluted from surface-expressed DAF than are parental CVA21 virions during a competitive epitope challenge by an anti-DAF SCR1 MAb suggests that interactions between CVA21-DAFv and DAF are of higher affinity than those of the parental strain. Nucleotide sequence analysis of the capsid-coding region of the CVA21-DAFv revealed the presence of two amino acid substitutions in capsid protein VP3 (R96H and E101A), possibly conferring the enhanced DAF-binding phenotype of CVA21-DAFv. These residues are predicted to be embedded at the interface of VP1, VP2, and VP3 and are postulated to enhance the affinity of DAF interaction occurring outside the capsid canyon. Taken together, the data clearly demonstrate an enhanced DAF-using phenotype and expanded receptor utilization of CVA21-DAFv compared to the parental strain, further highlighting that capsid interactions with DAF alone facilitate rapid multicycle lytic cell infection.     

Clinical features of headache associated with mobile phone use: a cross-sectional study in university students

Background  

Headache has been reported to be associated with mobile phone (MP) use in some individuals. The causal relationship between headache associated with MP use (HAMP) and MP use is currently undetermined. Identifying the clinical features of HAMP may help in clarifying the pathophysiology of HAMP and in managing symptoms of individuals with HAMP. The aim of the present study is to describe the clinical features of HAMP.     

Using concept maps to characterise cellular respiration knowledge in undergraduate students

ABSTRACT

Meaningful learning occurs by relating new information to and revising prior knowledge, making it essential to understand student knowledge before helping them move toward a more scientific understanding. In this study, we characterise prior knowledge about cellular respiration in undergraduate students enrolled in introductory biology by analysing student-constructed concept maps (N = 182) and interviews (N = 9). Students were instructed to create concept maps from a bank of 20 concepts with the purpose of interconnecting the processes of cellular respiration, showing how pools of ATP are generated and used, and identifying where the events of cellular respiration occur. Student maps were analysed for content, quality and organisation of knowledge. Interviews were used to corroborate inferences made from concept maps. Students had a simplified understanding of cellular respiration and its processes as evident by cognitive structures with limited quantities of schemas that were vaguely connected and linearly organised. Furthermore, students had a better understanding of glycolysis than fermentation. Instructors can use these findings to help students build better knowledge of cellular respiration by focusing on incorporating relevant schemas, creating quality connections among schemas, and organising their knowledge of cellular respiration to reflect biological complexity.     

大学生性知识和性行为调查分析

目的:了解大学生性知识、性行为情况,以提高大学生性教育的针对性和质量.方法:对600名18-24岁的大学生志愿者进行关于性传播疾病(STD)、性知识和性行为的问卷调查,通过调查结果探讨大学生性教育存在的问题和解决方案.结果:所有大学生对性传播疾病的名称比较熟悉,但对性传播疾病的症状和传播方式了解不多或有误解,性知识水平较低.大部分大学生没有接受过正规的性教育,对未婚同居和婚前性行为持开放态度,性知识主要来源于书籍和网络.大学生们认为性教育很有必要.结论:大学生性和生殖健康知识贫乏,年轻的大学生应当对他们可能遇到的常见的性传播疾病有所了解.大学生性教育应更加侧重于性传播疾病的传播途径及预防.     

The usage of cell phones and the feeling to them in modern Japanese college students

The aim of this study is to investigate how and to what extent modern people's life is affected by cell phones, which have been rapidly penetrating into the people's individual life. Surveys were conducted by questionnaires to Japanese college students (288 females and 54 males, ages 18 to 21) about their dependency on cell phones and habits of using them. The result was analyzed by the KJ method extracting the typical feelings about cell phones. Forty typical feelings were rated by 5 levels and analyzed in relation to the using years and the frequency per day. About 20% of the students used cell phones more than 30 times a day and for more than 3 hours in average per day. A decisive point concerning the users' dependency on cell phones seemed to exist between the daily use of 30 times and 40 times. At the same time, female students appeared more dependent on cell phones. Those feelings were classified into 6 groups; being 'dependent' on cell phones, regarding cell phones as 'important', 'necessary', 'convenient', just a 'method' of communication, and 'troublesome'. The percentages of those who felt cell phones as convenient, a method, important and necessary were high both in males and females. The dependence on cell phones seemed to be affirmative in both sexes, but males consistently felt cell phones as methods, whereas females tended to be more dependent on them from psychological reasons. Consequently, there were observed some differences between males and females in their use and feelings to cell phones.