ユーザのブラウジング習慣に基づく携帯端末でのWebページプリフェッチ技法

近年携帯端末の普及に伴って、PC の代わりに携帯端末用Web ブラウザを使用するユーザが増えてきた。そこで、携帯端末用Web ブラウザのパフォーマンスに対する要求が高くなってきた。Web プリフェッチは既存でよくWeb ブラウザのパフォーマンス向上のために使用されている方法の１つである。Web プリフェッチはユーザのWeb 履歴で次にユーザがアクセスする可能性のあるWeb リソースを事前に端末にロードする。次にユーザが使用する時、サーバとのやり取りなしで、速くユーザに画面に表示し、遅延を削減する。既存のPC でのWeb ブラウザのWeb プリフェッチ方法は沢山あるが、携帯端末バッテリ、使用可能な通信データ量、メモリ容量などの制限で流用できないものが多い。その理由としては、速度を出すために、携帯端末ではバッテリの使用が減り、通信データ量が大幅に増えるためである。既存のPC 上のプリフェッチ方法は適用できない。そこで、既存の手法を携帯端末で使用可能に改良する必要がある。本研究では携帯端末でのブラウジング習慣に基づき、ユーザがよくアクセスするWeb ページでマルコフ連鎖を作成し、さらに、条件によりキーワードをベースにしたプリフェッチ方法を合わせ、携帯端末のバッテリ、通信データの節約でき、かつ、ブラウジングパフォーマンスを向上するWeb ページプリフェッチ技法を提案し、実験で評価する。電気通信大学201

Purchasing Behavior, Setting, Pricing, Family: Determinants of School Lunch Participation

Despite growing school lunch availability in Germany, its utilization is still low, and students resort to unhealthy alternatives. We investigated predictors of school lunch participation and reasons for nonparticipation in 1215 schoolchildren. Children reported meal habits, parents provided family-related information (like socioeconomic status), and anthropometry was conducted on-site in schools. Associations between school lunch participation and family-related predictors were estimated using logistic regression controlling for age and gender if necessary. School was added as a random effect. School lunch participation was primarily associated with family factors. While having breakfast on schooldays was positively associated with school lunch participation (ORadj = 2.20, p = 0.002), lower secondary schools (ORadj = 0.52, p < 0.001) and low SES (ORadj = 0.25, p < 0.001) were negatively associated. The main reasons for nonparticipation were school- and lunch-related factors (taste, time constraints, pricing). Parents reported pricing as crucial a reason as an unpleasant taste for nonparticipation. Nonparticipants bought sandwiches and energy drinks significantly more often on school days, whereas participants were less often affected by overweight (OR = 0.66, p = 0.043). Our data stress school- and lunch-related factors as an important opportunity to foster school lunch utilization

ISCEV standard for clinical pattern electroretinography—2007 update

The pattern electroretinogram (PERG) is a retinal response evoked by viewing a temporally alternating pattern, usually a black and white checkerboard or grating. The PERG is important in clinical and research applications because it provides information both about retinal ganglion cell function and, because the stimulus is customarily viewed with central fixation, the function of the macula. The PERG can therefore facilitate interpretation of an abnormal pattern VEP by revealing the retinal responses to a similar stimulus to that used for the VEP. However, practitioners may have difficulty choosing between the different techniques for recording the PERG that have been described in the literature. The International Society for Clinical Electrophysiology of Vision published a standard for clinical PERG recording in 2000 to assist practitioners in obtaining good quality reliable responses and to facilitate inter-laboratory communication and comparison. This document is the scheduled revision of that standard

And yet Again: Having Breakfast Is Positively Associated with Lower BMI and Healthier General Eating Behavior in Schoolchildren

Given the high prevalence of childhood overweight, school-based programs aiming at nutritional behavior may be a good starting point for community-based interventions. Therefore, we investigated associations between school-related meal patterns and weight status in 1215 schoolchildren. Anthropometry was performed on-site in schools. Children reported their meal habits, and parents provided family-related information via questionnaires. Associations between nutritional behavior and weight status were estimated using hierarchical linear and logistic regression. Analyses were adjusted for age, socio–economic status, school type, migration background, and parental weight status. Having breakfast was associated with a lower BMI-SDS (βadj = −0.51, p = 0.004) and a lower risk of being overweight (ORadj = 0.30, p = 0.009), while having two breakfasts resulting in stronger associations (BMI-SDS: βadj = −0.66, p < 0.001; risk of overweight: ORadj = 0.22, p = 0.001). Likewise, children who regularly skipped breakfast on school days showed stronger associations (BMI-SDS: β = 0.49, p < 0.001; risk of overweight: OR = 3.29, p < 0.001) than children who skipped breakfast only occasionally (BMI-SDS: β = 0.43, p < 0.001; risk of overweight: OR = 2.72, p = 0.032). The associations persisted after controlling for parental SES and weight status. Therefore, our data confirm the school setting as a suitable starting point for community-based interventions and may underline the necessity of national programs providing free breakfast and lunch to children

Characteristics of period doubling in the rat cone flicker ERG

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Experimental Eye Research 90 (2010): 196-202, doi:10.1016/j.exer.2009.10.006.When the eye is stimulated by a flickering light, the electroretinogram (ERG) and other electrophysiological responses in the visual pathway often exhibit period doubling. This phenomenon is manifested as an alternation in the shape of the response waveform from cycle to cycle, and also as spectral components at the half-fundamental frequency (F/2) and its odd multiples. Although period doubling has been described in humans as well as in other animals, its features in the rodent flicker ERG have not been characterized. We investigated the properties of period doubling in the rat cone flicker ERG elicited with full field, sinusoidal photic stimuli. Period doubling was observed when the temporal frequency of the stimulus was in the range of 20 to 30 Hz. The F/2 component of the Fourier spectrum of the ERG was more pronounced than its odd harmonics. The magnitude of the cycle-to-cycle variation in amplitude differed depending on whether measurements were based on peak-to-trough or trough-to-peak amplitudes, owing to the relative phase relationship between F/2 and F as a function of stimulus frequency. The frequency-response characteristics of period doubling varied with stimulus contrast, such that reducing the contrast shifted the peak F/2 amplitude to a lower stimulus frequency. Period doubling was evident in rat eyes in which PDA was administered intravitreally, indicating that the phenomenon can occur independently of OFF-pathway activity in the rat retina. The period doubling properties we observed in the flicker ERG response of the rat cone system provide constraints on the nature of the nonlinear feedback mechanism presumed to underlie the period doubling phenomenon.This work was supported by a grant from the Pearle Vision Foundation (HQ), the Joyce Schroeder Fund (HQ), NIH research grant EY08301 (KRA), NIH core grant EY01792, an Alcon Research Institute Award (HR), RPB Senior Scientific Investigator Awards (KRA, HR), and an unrestricted departmental award from Research to Prevent Blindness, Inc