Coherent vibrational and dissociation dynamics of polyatomic radical cations

The ultrafast dynamics of polyatomic radical cat- ions contribute to important processes including energy transfer in photovoltaics, electron transfer in photocataly- sis, radiation-induced DNA damage, and chemical reac- tions in the upper atmosphere and space. Probing these dynamics in the gas phase is challenging due to the rapid dissociation of polyatomic radical cations following elec- tron removal, which arises from excess electronic excita- tion of the molecule during the ionization process. This Concept article introduces the reader to how the pump- probe technique of femtosecond time-resolved mass spectrometry (FTRMS) can overcome this challenge to capture coherent vibrational dynamics on the femtosec- ond timescale in polyatomic radical cations and enable the analysis of their dissociation pathways. Examples of FTRMS applied to three families of polyatomic radical cat- ions are discussed

Health Needs Assessment for Kumasi, Ghana

In early 2006 Professor Jeffrey Sachs, Director of the Earth Institute (EI) at Columbia University, launched Kumasi as a Millennium City. Since then, the EI’s Millennium Cities Initiative (MCI) has conducted research aimed at identifying the services, resources and infrastructure needed for the people of Kumasi to attain the Millennium Development Goals (MDGs), a set of universally endorsed, quantifiable targets established by the United Nations to point the way out of extreme poverty for the planet’s poorest billion

Medical student self-efficacy, knowledge and communication in adolescent medicine

Objectives To evaluate student self-efficacy, knowledge and communication with teen issues and learning activities. Methods Data were collected during the 8-week pediatric rotation for third–year medical students at a local children’s hospital. Students completed a self-efficacy instrument at the beginning and end of the rotation; knowledge and communication skills were evaluated during standardized patient cases as part of the objective structured clinical examination. Self-efficacy, knowledge and communication frequencies were described with descriptive statistics; differences between groups were also evaluated utilizing two-sample t-tests. Results Self-efficacy levels of both groups increased by the end of the pediatric rotation, but students in the two-lecture group displayed significantly higher self-efficacy in confidentiality with adolescents (t(35)=-2.543, p=0.02); interviewing adolescents, assessing risk, sexually transmitted infection risk and prevention counseling, contraception counseling were higher with marginal significance. No significant differences were found between groups for communication; assessing sexually transmitted infection risk was marginally significant for knowledge application during the clinical exam. Conclusions Medical student self-efficacy appears to change over time with effects from different learning methods; this higher self-efficacy may increase future comfort and willingness to work with this high-risk, high-needs group throughout a medical career

Assessment of yield losses due to early and late leaf spots of groundnut (Arachis hypogaea L.)

Early leaf spot (Cercospora arachidicola) and late leaf spot (sporidium personatum) are major limiting factors to groundnut productivity in northern Ghana. Fourteen groundnut entries were evaluated for two seasons (2003 and 2004) at Nyankpala with and without tebuconazole fungicide application. The objective of this study was to determine the yield losses due to combined attack of both diseases, with and without using tebuconazole (Folicur 3.6F) at 0.22 kg a.i. ha-1. The experiments were established in a split-plot design with three replications. Disease rating and pod yield were recorded at harvest maturity. Yield losses varied considerably, depending on entry and its yield potential. Pod yield losses due to both diseases ranged from 9.7 to 81.2 per cent in 2003, and from 19.5 to 65.9 per cent in 2004 when yield of protected entries was compared with yield of unprotected entries. The application of fungicide was effective in controlling leaf spots and improved pod yields across the two seasons. Some entries treated with fungicide produced pod yield of 1,860 to 2,081 kg ha-1, which is more than 2 to 2½-fold increase over present average yields in Ghana. Based on the high yield losses, chemical control and host-plant resistance options for managing both diseases in the north are recommended to enhance groundnut production. La tache à feuilles précoce (Cercospora arachidicola) et la tache à feille tardice (Cercosporidium personatum) sont des facteurs contraignants majeurs à la productivité d\'arachide dans le nord du Ghana. Quartorze variétés d\'arachide étaient évaluées pour deux saisons (2003 et 2004) à Nyankpala avec ou sans application de fongicide. Le but de ce travail de recherche était de déterminer les pertes de rendement en raison d\'attaque combinée des deux maladies en utilsant tébuconazole (Folicur 3.6F) à 0.22 kg a. i./ha. Les expériences étaient étabiles dans un dessin de lot-divisé avec trois répétitions. L\'indice de maladie et le rendement de cosse dues aux deux maladies variant entre 9.7 et 81.2% en l\'année 2003 et entre 19.5 et 65.9% en l\'année 2004 lorsque le rendment des varétés protégées avec fongicide était comparé avec le rendement des variétés non protégées. Application de fongicide était efficace dans la lutte contre les taches à feuille et améliorait également les rendements de cosse au cours de deux saisons. Quelques variétés traitées de fongicide donnaient un rendement de cosse de 1,860 à 2,081 kg/ha qui est plus 2 ou 2½ fois d\'augmentation par rapport aux randements moyens actuels au Ghana. Fondé sur les pertes de tendement élevées, l\'enrayement chimique et les options de plante-hôte résistante sont recommandés pour la lutte contre les deux maladies dans le nord afin d\'améliorer la production d\'arachide. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 21-2

Chemopreventive Potential of Synergy1 and Soybean in Reducing Azoxymethane-Induced Aberrant Crypt Foci in Fisher 344 Male Rats

Synergy1, a prebiotic composed of Inulin and Oligofructose (1 : 1). Soybean meal is a natural source of isoflavones. The objective was to investigate the effects of feeding Synergy1 and SM on the incidence of azoxymethane- (AOM-) induced aberrant crypt foci (ACF) in Fisher 344 male rats. Rats (54) were randomly assigned to 9 groups (n = 6). Control group (C) was fed AIN-93G and treatment groups Syn1 and SM at 5% and 10% singly and in combinations. Rats were injected with two s/c injections of AOM at 7 and 8 weeks of age at 16 mg/kg body weight and killed at 17 weeks by CO2 asphyxiation. Colonic ACF enumeration and hepatic enzyme activities were measured. Reductions (%) in total ACF among treatment groups fed combinations were higher (67–77) compared to groups fed singly (52–64). Synergistic mechanisms among phytochemicals may be responsible suggesting protective role in colon carcinogenesis with implications in food product development

A Smartwatch Step-Counting App for Older Adults: Development and Evaluation Study

Background: Older adults who engage in physical activity can reduce their risk of mobility impairment and disability. Short amounts of walking can improve quality of life, physical function, and cardiovascular health. Various programs have been implemented to encourage older adults to engage in physical activity, but sustaining their motivation continues to be a challenge. Ubiquitous devices, such as mobile phones and smartwatches, coupled with machine-learning algorithms, can potentially encourage older adults to be more physically active. Current algorithms that are deployed in consumer devices (eg, Fitbit) are proprietary, often are not tailored to the movements of older adults, and have been shown to be inaccurate in clinical settings. Step-counting algorithms have been developed for smartwatches, but only using data from younger adults and, often, were only validated in controlled laboratory settings. Objective: We sought to develop and validate a smartwatch step-counting app for older adults and evaluate the algorithm in free-living settings over a long period of time. Methods: We developed and evaluated a step-counting app for older adults on an open-source wrist-worn device (Amulet). The app includes algorithms to infer the level of physical activity and to count steps. We validated the step-counting algorithm in the lab (counting steps from a video recording, n=20) and in free-living conditions—one 2-day field study (n=6) and two 12-week field studies (using the Fitbit as ground truth, n=16). During app system development, we evaluated 4 walking patterns: normal, fast, up and down a staircase, and intermittent speed. For the field studies, we evaluated 5 different cut-off values for the algorithm, using correlation and error rate as the evaluation metrics. Results: The step-counting algorithm performed well. In the lab study, for normal walking (R2=0.5), there was a stronger correlation between the Amulet steps and the video-validated steps; for all activities, the Amulet’s count was on average 3.2 (2.1%) steps lower (SD 25.9) than the video-validated count. For the 2-day field study, the best parameter settings led to an association between Amulet and Fitbit (R2=0.989) and 3.1% (SD 25.1) steps lower than Fitbit, respectively. For the 12-week field study, the best parameter setting led to an R2 value of 0.669. Conclusions: Our findings demonstrate the importance of an iterative process in algorithm development before field-based deployment. This work highlights various challenges and insights involved in developing and validating monitoring systems in real-world settings. Nonetheless, our step-counting app for older adults had good performance relative to the ground truth (a commercial Fitbit step counter). Our app could potentially be used to help improve physical activity among older adults

Combinational Effects of Prebiotics and Soybean against Azoxymethane-Induced Colon Cancer In Vivo

Prebiotic fructans are nondigestible carbohydrates with numerous health benefits. Soybean is a rich source of phytonutrients such as isoflavones. The objective of this study was to evaluate the chemopreventive effects of prebiotics (Synergy1) and soybean meal (SM) at 5% and 10% levels alone and in combination on azoxymethane- (AOM-) induced colon carcinogenesis. After one wk of acclimatization, Fisher 344 male rats (N = 90) were randomly assigned to 9 groups (n = 10). Control rats (C) were fed AIN-93G/M. Two s/c injections of AOM were administered to rats at 7 and 8 wk of age at 16 mg/kg body weight. Rats were killed by CO2 asphyxiation at 45 wk. Tumor incidence (%) in treatment groups ranged from 40 to 75 compared to 100 in C. Results indicate that feeding prebiotics and soybean in combination significantly reduced incidence of AOM-induced colon tumors with implications for food industry in the food-product development