In vitro expression and antiserum production against the movement protein of Citrus leprosis virus C (CiLV-C)

Citrus leprosis, caused by Citrus leprosis virus C (CiLV-C), is currently considered the most important viral disease in the Brazilian citrus industry due to the high costs required for the chemical control of its vector, the mite Brevipalpus phoenicis. The pathogen induces a non-systemic infection and the disease is characterized by the appearance of localized lesions on citrus leaves, stems and fruits, premature fruit and leaf drop and dieback of stems. Attempts were made to promote in vitro expression of the putative cell-to-cell movement protein of CiLV-C in Escherichia coli and to produce a specific polyclonal antibody against this protein as a tool to investigate the virus-plant-vector relationship. The antibody reacted strongly with the homologous protein expressed in vitro by ELISA, but poorly with the native protein present in leaf lesion extracts from sweet orange caused by CiLV-C. Reactions from old lesions were more intense than those from young lesions. Western blot and in situ immunolocalization assays failed to detect the native protein. These results suggest low expression of the movement protein (MP) in host tissues. Moreover, it is possible that the conformation of the protein expressed in vitro and used to produce the antibody differs from that of the native MP, hindering a full recognition of the latter.

Manipolazione del metabolismo degli xenobiotici da frutta convenzionale ed attività chemiopreventiva

A reduced cancer risk associated with fruit and vegetable phytochemicals initially dictated chemopreventive approaches focused on specific green variety consumption or even single nutrient supplementations. However, these strategies not only failed to provide any health benefits but gave rise to detrimental effects. In parallel, public-health chemoprevention programmes were developed in the USA and Europe to increase whole vegetable consumption. Among these, the National Cancer Institute (NCI) sponsored plan “5 to 9 a day for a better health” was one of the most popular. This campaign promoted wide food choice through the consumption of at least 5 to 9 servings a day of colourful fruits and vegetables. In this study the effects of the diet suggested by NCI on transcription, translation and catalytic activity of both xenobiotic metabolizing (XME) and antioxidant enzymes were studied in the animal model. In fact, the boost of both antioxidant defences and “good” phase-II together with down-regulation of “bad” phase-I XMEs is still considered one of the most widely-used strategies of cancer control. Six male Sprague Dawley rats for each treatment group were used. According to the Italian Society of Human Nutrition, a serving of fruit, vegetables and leafy greens corresponds to 150, 250 and 50 g, respectively, in a 70 kg man. Proportionally, rats received one or five servings of lyophilized onion, tomato, peach, black grape or lettuce – for white, red, yellow, violet or green diet, respectively - or five servings of each green (“5 a day” diet) by oral gavage daily for 10 consecutive days. Liver subcellular fractions were tested for various cytochrome P450 (CYP) linked-monooxygenases, phase-II supported XMEs such as glutathione S-transferase (GST) and UDP-glucuronosyl transferase (UDPGT) as well as for some antioxidant enzymes. Hepatic transcriptional and translational effects were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. dROMs test was used to measure plasmatic oxidative stress. Routine haematochemical parameters were also monitored. While the five servings administration didn’t significantly vary XME catalytic activity, the lower dose caused a complex pattern of CYP inactivation with lettuce exerting particularly strong effects (a loss of up to 43% and 45% for CYP content and CYP2B1/2-linked XME, respectively; P<0.01). “5 a day” supplementation produced the most pronounced modulations (a loss of up to 60% for CYP2E1-linked XME and a reduction of CYP content of 54%; P<0.01). Testosterone hydroxylase activity confirmed these results. RT-PCR and Western blot analysis revealed that the “5 a day” diet XMEs inactivations were a result of both a transcriptional and a translational effect while lettuce didn’t exert such effects. All administrations brought out none or fewer modulation of phase-II supported XMEs. Apart from “5 a day” supplementation and the single serving of lettuce, which strongly induced DT- diaphorase (an increase of up to 141 and 171%, respectively; P<0.01), antioxidant enzymes were not significantly changed. RT-PCR analysis confirmed DT-diaphorase induction brought about by the administration of both “5 a day” diet and a single serving of lettuce. Furthermore, it unmasked a similar result for heme-oxygenase. dROMs test provided insight into a condition of high systemic oxidative stress as a consequence of animal diet supplementation with “5 a day” diet and a single serving of lettuce (an increase of up to 600% and 900%, respectively; P<0.01). Haematochemical parameters were mildly affected by such dietary manipulations. According to the classical chemopreventive theory, these results could be of particular relevance. In fact, even if antioxidant enzymes were only mildly affected, the phase-I inactivating ability of these vegetables would be a worthy strategy to cancer control. However, the recorded systemic considerable amount of reactive oxygen species and the complexity of these enzymes and their functions suggest caution in the widespread use of vegan/vegetarian diets as human chemopreventive strategies. In fact, recent literature rather suggests that only diets rich in fruits and vegetables and poor in certain types of fat, together with moderate caloric intake, could be associated with reduced cancer risk.

Study of Italian isolates of Alternaria spp.: molecular and morphological characterization and pathogenesis on apple tree

It was decided to carry out a morphological and molecular characterization of the Italian Alternaria isolatescollected from apple , and evaluate their pathogenicity and subsequently combining the data collected. The strain collection (174 isolates) was constructed by collecting material (received from extension service personnel) between June and August of 2007, 2008, and 2009. A Preliminary bioassays were performed on detached plant materials (fruit and leaf wounded and unwounded), belonging to the Golden cultivar, with two different kind of inoculation (conidial suspension and conidial filtrate). Symptoms were monitored daily and a value of pathogenicity score (P.S.) was assigned on the basis of the diameter of the necrotic area that developed. On the basis of the bioassays, the number of isolates to undergo further molecular analysis was restricted to a representative set of single spore strains (44 strains). Morphological characteristics of the colony and sporulation pattern were determined according to previous systematic work on small-spored Alternaria spp. (Pryor and Michaelides, 2002 and Hong et al., 2006). Reference strains (Alternaria alternata, Alternaria tenuissima, Alternaria arborescens and four Japanese strains of Alternaria alternata mali pathotype), used in the study were kindly provided by Prof. Barry Pryor, who allows a open access to his own fungal collection. Molecular characterization was performed combining and comparing different data sets obtained from distinct molecular approach: 1) investigation of specific loci and 2) fingerprinting based on diverse randomly selected polymorphic sites of the genome. As concern the single locus analysis, it was chosen to sequence the EndoPG partial gene and three anonymous region (OPA1-3, OPA2- and OPa10-2). These markers has revealed a powerful tool in the latter systematic works on small-spored Alternaria spp. In fact, as reported in literature small-spored Alternaria taxonomy is complicated due to the inability to resolve evolutionary relationships among the taxa because of the lack of variability in the markers commonly used in fungi systematic. The three data set together provided the necessary variation to establish the phylogenetic relationships among the Italian isolates of Alternaria spp. On Italian strains these markers showed a variable number of informative sites (ranging from 7 for EndoPg to 85 for OPA1-3) and the parsimony analysis produced different tree topologies all concordant to define A. arborescens as a mophyletic clade. Fingerprinting analysis (nine ISSR primers and eight AFLP primers combination) led to the same result: a monophyleic A. arborescens clade and one clade containing both A. tenuissima and the A. alternata strains. This first attempt to characterize Italian Alternaria species recovered from apple produced concordant results with what was already described in a similar phylogenetic study on pistachio (Pryor and Michaelides, 2002), on walnut and hazelnut (Hong et al., 2006), apple (Kang et al., 2002) and citurus (Peever et al., 2004). Together with these studies, this research demonstrates that the three morphological groups are widely distributed and occupy similar ecological niches. Furthermore, this research suggest that these Alternaria species exhibit a similar infection pattern despite the taxonomic and pathogenic differences. The molecular characterization of the pathogens is a fundamental step to understanding the disease that is spreading in the apple orchards of the north Italy. At the beginning the causal agent was considered as Alteraria alternata (Marshall and Bertagnoll, 2006). Their preliminary studies purposed a pathogenic system related to the synthesis of toxins. Experimental data of our bioassays suggest an analogous hypothesis, considering that symptoms could be induced after inoculating plant material with solely the filtrate from pathogenic strains. Moreover, positive PCR reactions using AM-toxin gene specific primers, designed for identification of apple infecting Alternaria pathovar, led to a hypothesis that a host specific toxin (toxins) were involved. It remains an intriguing challenge to discover or not if the agent of the “Italian disease” is the same of the one previously typified as Alternaria mali, casual agent of the apple blotch disease.

Expression profiling in developing peach seed and mesocarp as affected by growth regulators

Jasmonates (JAs) and spermidine (Sd) influence fruit (and seed) development and ripening. In order to unravel their effects in peach fruit, at molecular level, field applications of methyl jasmonate (MJ) and propyl dihydrojasmonate (PDJ), and Sd were performed at an early developmental stage (late S1). At commercial harvest, JA-treated fruit were less ripe than controls. Realtime RT-PCR analyses confirmed a down-regulation of ethylene biosynthetic, perception and signaling genes, and flesh softening-related genes. The expression of cell wall-related genes, of a sugar-transporter and hormone-related transcript levels was also affected by JAs. Seeds from JA-treated fruit showed a shift in the expression of developmental marker genes suggesting that the developmental program was probably slowed down, in agreement with the contention that JAs divert resources from growth to defense. JAs also affected phenolic content and biosynthetic gene expression in the mesocarp. Levels of hydroxycinnamic acids, as well as those of flavan-3-ols, were enhanced, mainly by MJ, in S2. Transcript levels of phenylpropanoid pathway genes were up-regulated by MJ, in agreement with phenolic content. Sd-treated fruits at harvest showed reduced ethylene production and flesh softening. Sd induced a short-term and long-term response patterns in endogenous polyamines. At ripening the up-regulation of the ethylene biosynthetic genes was dramatically counteracted by Sd, leading to a down-regulation of softening-related genes. Hormone-related gene expression was also altered both in the short- and long-term. Gene expression analyses suggest that Sd interfered with fruit development/ripening by interacting with multiple hormonal pathways and that fruit developmental marker gene expression was shifted ahead in accord with a developmental slowing down. 24-Epibrassinolide was applied to Flaminia peaches under field conditions early (S1) or later (S3) during development. Preliminary results showed that, at harvest, treated fruit tended to be larger and less mature though quality parameters did not change relative to controls.

Phylogenetically independent associations between autonomous self-fertilization and plant invasiveness

Many plant species have been introduced from their native ranges to new continents, but few have become naturalized or, ultimately, invasive. It has been predicted that species that do not require the presence of compatible mates and the services of pollinators for reproduction will be favored in establishment after long-distance dispersal. We tested whether this hypothesis, generally referred to as Baker's law, holds for South African species of Iridaceae ( iris family) that have been introduced in other regions for horticultural purposes. Fruit and seed production of flowers from which pollinators had been experimentally excluded was assessed for 10 pairs of species from nine different genera or subgenera. Each species pair comprised one naturalized and one nonnaturalized species, all of which are used in international horticulture. On average, species of Iridaceae that have become naturalized outside their native ranges showed a higher capacity for autonomous fruit and seed production than congeneric species that have not become naturalized. This was especially true for the naturalized species that are considered to be invasive weeds. These results provide strong evidence for the role of autonomous seed production in increasing potential invasiveness in plants.

Prevalence of tooth wear on buccal and lingual surfaces and possible risk factors in young European adults

To assess the prevalence of tooth wear on buccal/facial and lingual/palatal tooth surfaces and identify related risk factors in a sample of young European adults, aged 18-35 years. Calibrated and trained examiners measured tooth wear, using the basic erosive wear examination (BEWE) on in 3187 patients in seven European countries and assessed the impact of risk factors with a previously validated questionnaire. Each individual was characterized by the highest BEWE score recorded for any scoreable surface. Bivariate analyses examined the proportion of participants who scored 2 or 3 in relation to a range of demographic, dietary and oral care variables. The highest tooth wear BEWE score was 0 for 1368 patients (42.9%), 1 for 883 (27.7%), 2 for 831 (26.1%) and 3 for 105 (3.3%). There were large differences between different countries with the highest levels of tooth wear observed in the UK. Important risk factors for tooth wear included heartburn or acid reflux, repeated vomiting, residence in rural areas, electric tooth brushing and snoring. We found no evidence that waiting after breakfast before tooth brushing has any effect on the degree of tooth wear (p=0.088). Fresh fruit and juice intake was positively associated with tooth wear. In this adult sample 29% had signs of tooth wear making it a common presenting feature in European adults.

DNA, Red Tide and the Sea: a new exhibit at Mystic Aquarium & IFE

DNA, Red Tide and the Sea is a new exhibit at Mystic Aquarium & IFE. It was developed by UConn Marine Sciences Professor Senjie Lin, and Mystic Aquarium. Children can extract DNA from fruit and learn about genetic codes and red tides in the ocean.

Estimated current patterns of food consumption and perceived changes among patients with lymphoma

Usual food choices during the past year, self-reported changes in consumption of three important food groups, and weight changes or stability were the questions addressed in this cross-sectional survey and retrospective review. The subjects were 141 patients with Hodgkin's disease or other B-cell types of lymphoma within their first three years following completion of initial treatments for lymphoma at the University of Texas M. D. Anderson Cancer Center in Houston, Texas. ^ The previously validated Block-98 Food Frequency Questionnaire was used to estimate usual food choices during the past year. Supplementary questions asked about changes breads and cereals (white or whole grain) and relative amounts of fruits and vegetables compared with before diagnosis and treatment. Over half of the subjects reported consuming more whole grains, fruits, and/or vegetables and almost three quarters of those not reporting such changes had been consuming whole grains before diagnosis and treatment. ^ Various dietary patterns were defined in order to learn whether proportionately more patients who changed in healthy directions fulfilled recognized nutritional guidelines such as 5-A-day fruits and vegetables and Dietary Reference Intakes (DRIB) for selected nutrients. ^ Small sizes of dietary pattern sub-groups limited the power of this study to detect differences in meeting recommended dietary guidelines. Nevertheless, insufficient and excessive intakes were detected among individuals with respect to fruits and vegetables, fats, calcium, selenium, iron, folate, and Vitamin A. The prevalence of inadequate or excess intakes of foods or nutrients even among those who perceived that they had increased or continued to eat whole grains and/or fruits and vegetables is of concern because of recognized effects upon general health and potential cancer related effects. ^ Over half of the subjects were overweight or obese (by BMI category) on their first visit to this cancer center and that proportion increased to almost three-quarters by their last follow-up visits. Men were significantly heavier than women, but no other significant differences in BMI measures were found even after accounting for prescribed steroids and dietary patterns. ^

Determining the feasibility and acceptability of a garden-based nutrition curriculum for preschoolers

Obesity rates around the nation have risen to epidemic proportions. Rates of childhood obesity are at very high levels with 24.4% of preschool-aged children in the U.S. currently considered as overweight or obese. The percentage of childhood obesity is much higher in the southern part of the United States as compared to the rest of the nation. Minority populations, especially African American and Hispanic, are affected more than other ethnic groups. Obesity prevention programs are needed targeting young children <6 years of age from minority populations. Currently, there are few obesity prevention programs that have been implemented and evaluated in children <6 years of age. Gardening programs have been successful in improving the health status of elementary school children by increasing fruit and vegetable intake and increasing preferences for healthier food choices. However, there is no evidence of the feasibility and acceptability of a garden-based obesity prevention program among preschoolers. This pretest study, a classroom-based gardening curriculum program with 16 lesson plans and coordinating activities for preschool age children (3-5 years old) enrolled in Head Start, provides the opportunity to address this need. The study included 103 preschoolers from two centers and 9 teachers or teachers' aides. Qualitative data on feasibility and acceptability was collected from process evaluation forms of individual lesson plans and focus groups with teachers. Teacher questionnaires assessed individual teacher characteristics and provided feedback regarding the curriculum. Quantitative measures of teachers' self-efficacy, attitudes, and knowledge pertaining to nutrition were analyzed from pre and post-test surveys. Results revealed this preschool garden-based nutrition curriculum was both feasible and acceptable. The program improved teacher's self-efficacy, knowledge, and attitudes about nutrition, with teacher's confidence in ability to teach a gardening curriculum increasing from a mean score of 2.14 to 3.00 from pre to post test (P value = 0.0046). These results indicate implementing garden-based nutrition lessons within preschools is achievable. Employing garden-based nutrition lessons in the classroom is the first step in teaching children about nutrition and gardening concepts. Constructing gardening beds for more hands-on learning is the next proposed step in the larger parent study of this program.^

Stages of change and carotene intake in the Paso del Norte region: Que Sabrosa Vida

Understanding a population's dietary behavior is important to promote behaviors which have the most beneficial impact on health. The most recent Dietary Guidelines for Americans (2005) identifies carotenoids as a key nutrient to be consumed through increased intake of fruits and vegetables (FV). While some studies have included or focused on the Hispanic population, few have focused only on Mexican-American populations and staged its intake of FV. Stage of change behavior theory has been used to understand the adoption and promotion of healthy behaviors such as increased intake of FV. It has been shown to effectively aid interventionists' understanding of dietary behavior. Intake patterns of FV of older women, rural residents, and adolescents of Mexican American descent have been conducted but not by stages of change. This study aimed to determine the relationship between stages of change for fruits and vegetables (SOC-FV) and total carotene intake to assess the quality of SOC-FV as a surrogate measure of total carotene. ^ Data from the 2000 Qué Sabrosa Vida Community Nutrition Survey (QSV-CNS) were analyzed to identify the SOC-FV and sources of carotenes in a Mexican American population 18-60 yrs. of the Paso del Norte region. A 107 item interviewer administered food frequency questionnaire (FFQ) specifically calibrated for a Mexican American population was used to collect usual intake of total carotene. The QSV survey study population included 963 participants, 590 (61.3%) women and 373 (38.7%) men. A statistically significant mean difference in caloric intake between men and women was found (p-value = <0.01). When total carotene intake was adjusted for energy, there were significant differences between men and women (p-value = <0.0001) with women consuming a higher amount of total carotene (406 RE/kcal 1,000) than men (332 RE/kcal 1000). The food sources of total carotene for both genders included many items found in a traditional Mexican American diet. Chile, after carrots, was the highest contributor of dietary carotene. Total carotene intake was not associated with stages of change among women or men and their distributions were not linear. Mean differences of total carotene by stages of change were significant for women for pre-contemplation/contemplation (p-value = 0.04) and preparation (p-value = 0.0004) but not for men. ^ SOC-FV may serve as a surrogate measure for dietary carotene intake. This study's Mexican American population had a high carotene quality diet derived from traditional food items irrespective of their stage of change for fruits and vegetables. To better understand this population's dietary intake a measure for acculturation should be included. Interventions aimed at Mexican American populations should aim to promote traditional diets consistent with cultural practices.^ ^

A descriptive analysis of the consumers at farm stands outside WIC clinics

Because fruit and vegetable intake remains low in low-income populations, the attention of public health researchers has focused on different strategies to reach this population. One possible method of reaching low income populations is through government food assistance programs like the WIC's Farmers Market Nutrition Program (FMNP). This program provides vouchers to WIC recipients that are redeemable only at farmers' markets. In the summer of 2010, two farm stands near WIC clinics in Austin were surveyed in order to establish socio-demographic characteristics of the clientele of the markets. The overall purpose of this pilot study was to describe the clientele of the markets and to examine associations between food insecurity, acculturation, socio-demographic factors, and farmers' market participants' fruit and vegetable intake. The sample was a convenience sample of farmers' market customers. One hundred study participants completed self-administered surveys. Independent t-tests were used to explore the differences in means of fruit and vegetable intake according to acculturation and food insecurity levels. The overall mean (SD) of daily fruit and vegetable intake was 4.20±2.69 for customers of both markets. Significant differences were reported between the two markets in overall fruit and vegetable intake and specifically in the following: 100% juice (P=.023), fruit consumption (P=.028), green salad (P=.003), and salsa (P=.044). The differences showed that customers at the market in a more busy location were on average reporting eating more fruits and vegetables than customers at another market that was located in a more secluded location. When examined by level of food security, individuals who were more food secure consumed more fruit (P=.016). When examined by level of acculturation, the overall fruit and vegetable intake was not significantly different between levels of acculturation. The overall findings in this report suggest that the population at these markets consists of individuals who are food insecure and on government assistance programs. While there were no significant differences between fruit and vegetable intake, acculturation and food insecurity, this report suggests the need for culturally tailored interventions that serve the Hispanic population and would assist this population to become more food secure.^

Effects of a health advocacy program to promote physical activity and nutrition behaviors among adolescents: An evaluation of the Young Leaders for Healthy Change program

Background. This study was designed to evaluate the effects of the Young Leaders for Healthy Change program, an internet-delivered program in the school setting that emphasized health advocacy skills-development, on nutrition and physical activity behaviors among older adolescents (13–18 years). The program consisted of online curricular modules, training modules, social media, peer and parental support, and a community service project. Module content was developed based on Social Cognitive Theory and known determinants of behavior for older adolescents. ^ Methods. Of the 283 students who participated in the fall 2011 YL program, 38 students participated in at least ten of the 12 weeks and were eligible for this study. This study used a single group-only pretest/posttest evaluation design. Participants were 68% female, 58% white/Caucasian, 74% 10th or 11th graders, and 89% mostly A and/or B students. The primary behavioral outcomes for this analysis were participation in 60-minutes of physical activity per day, 20-minutes of vigorous- or moderate- intensity physical activity (MVPA) participation per day, television and computer time, fruit and vegetable (FV) intake, sugar-sweetened beverage intake, and consumption of breakfast, home-cooked meals, and fast food. Other outcomes included knowledge, beliefs, and attitudes related to healthy eating, physical activity, and advocacy skills. ^ Findings. Among the 38 participants, no significant changes in any variables were observed. However, among those who did not previously meet behavioral goals there was an 89% increase in students who participated in more than 20 minutes of MVPA per day and a 58% increase in students who ate home-cooked meals 5–7 days per week. The majority of participants met program goals related to knowledge, beliefs, and attitudes prior to the start of the program. Participants reported either maintaining or improving to the goal at posttest for all items except FV intake knowledge, taste and affordability of healthy foods, interest in teaching others about being healthy, and ease of finding ways to advocate in the community. ^ Conclusions. The results of this evaluation indicated that promoting healthy behaviors requires different strategies than maintaining healthy behaviors among high school students. In the school setting, programs need to target the promotion and maintenance of health behaviors to engage all students who participate in the program as part of a class or club activity. Tailoring the program using screening and modifying strategies to meet the needs of all students may increase the potential reach of the program. The Transtheoretical Model may provide information on how to develop a tailored program. Additional research on how to utilize the constructs of TTM effectively among high school students needs to be conducted. Further evaluation studies should employ a more expansive evaluation to assess the long-term effectiveness of health advocacy programming.^

The role of youth sports in public health

Study 1: Schools provide a range of opportunities for youth to be active, however, over the past decade, these opportunities have been declining. Sports teams are a promising venue to promote physical activity yet limited research has examined the gender an ethnic differences in sport participation. The purpose of this study is to examine trends in sport participation from 1991-2009 among US high school students. Secondly, we examined the association between gender and ethnicity with sports over time. This serial cross-sectional study used surveillance data from the Youth Risk Behavior Survey, a probability based sample weighted to represent gender and race/ethnic subpopulations of US high school students. The findings of this paper reveal persistent gender and ethnic disparities for sports participation among US youth. Since sports teams may provide a substantial source of physical activity, greater efforts should be undertaken to increase the participation of girls, especially minorities, in sports teams. ^ Study 2: Sports team participation is congruent with teaching and supporting healthy eating, yet limited research has examined the association between sports participation and dietary behaviors. This study aims to determine the association between youth sports participation and dietary behaviors among elementary-aged children. Significant dose-response associations were observed between number of sports teams and consumption of most fruits and vegetables. The likelihood of eating fruit for boys increased with the number of sports teams (1 team: OR=1.89; 3 teams: OR=3.44, p<0.001) and the likelihood of consuming green vegetables for girls was higher with the number of sports teams (1 team: OR=1.50; 3 teams: OR=2.39; p<0.001). For boys, the odds of consuming fruit-flavored drinks was higher ( p=0.019) and the odds of drinking soda was lower (p=0.018) with participation in increasing number of sports teams whereas for girls, sports participation was positively associated with diet soda consumption (p=0.006). ^ Study 3: Parents and peers have been shown to have a strong influence over the physical activity, dietary, and sedentary behaviors of youth. Youth sports teams have the potential to offer physical activity, displace sedentary behaviors, and promote a healthy diet. The purpose of this study is to assess how peer and parental support for physical activity and healthy eating, coupled with sport participation, is associated obesity related risk factors including diet and sedentary behaviors. A secondary analysis of data from the School Physical Activity and Nutrition study, a state-representative survey, was conducted. Eighth (n=3,931) and 11th (n=2,785) grade students were categorized into four groups based upon the level of peer and parental support derived from a three item scale and their participation in sports (sports/high support, sports/low support, no sports/high support, no sports/low support). Linear models were conducted to determine the difference in means between these groups for the following outcome variables: previous day fruit and vegetable intake, scores for an unhealthy and healthy food index, and hours spent watching television, playing video games, and working on a computer. Eighth graders had significantly greater levels of parental support for healthy eating and physical activity compared to 11th grade. Both 8 th and 11th graders in the sport/high support for healthy eating from peers and parents scored significantly higher on the healthy food index than other groups. Eighth and 11th graders in the sport/high support for physical activity from peers participated in fewer hours of sedentary behaviors than any other group (p ≤ 0.032). Although it is thought that sport participation may offer opportunities to support a healthy diet and displace sedentary time by offering providing physical activity, our study found that parental and peer support for activity and healthy eating may further attenuate this association. Parents and peer support should be an important target when developing strategies to improve healthy diets and reduce sedentary time among youth, especially in the context of youth sports. (Abstract shortened by UMI.)^

Structural conservations and diversities of dsRNA viruses: Structural studies of the cytoplasmic polyhedrosis virus by electron cryomicroscopy and 3D reconstruction

The Reoviridae virus family is a group of economically and pathologically important viruses that have either single-, double-, or triple-shelled protein layers enclosing a segmented double stranded RNA genome. Each virus particle in this family has its own viral RNA dependent RNA polymerase and the enzymatic activities necessary for the mature RNA synthesis. Based on the structure of the inner most cores of the viruses, the Reoviridae viruses can be divided into two major groups. One group of viruses has a smooth surfaced inner core, surrounded by complete outer shells of one or two protein layers. The other group has an inner core decorated with turrets on the five-fold vertices, and could either completely lack or have incomplete outer protein layers. The structural difference is one of the determinant factors for their biological differences during the infection. ^ Cytoplasmic polyhedrosis virus (CPV) is a single-shelled, turreted virus and the structurally simplest member in Reoviridae. It causes specific chronic infections in the insect gut epithelial cells. Due to its wide range of insect hosts, CPV has been engineered as a potential insecticide for use in fruit and vegetable farming. Its unique structural simplicity, unparalleled capsid stability and ease of purification make CPV an ideal model system for studying the structural basis of dsRNA virus assembly at the highest possible resolution by electron cryomicroscopy (cryoEM) and three-dimensional (3D) reconstruction. ^ In this thesis work, I determined the first 3D structure of CPV capsids using 100 kV cryoEM. At an effective resolution of 17 Å, the full capsid reveals a 600-Å diameter, T = 1 icosahedral shell decorated with A and B spikes at the 5-fold vertices. The internal space of the empty CPV is unoccupied except for 12 mushroom-shaped densities that are attributed to the transcriptional enzyme complexes. The inside of the full capsid is packed with icosahedrally-ordered viral genomic RNA. The interactions of viral RNA with the transcriptional enzyme complexes and other capsid proteins suggest a mechanism for RNA transcription and subsequent release. ^ Second, the interactions between the turret proteins (TPs) and the major capsid shell protein (CSPs) have been identified through 3D structural comparisons of the intact CPV capsids with the spikeless CPV capsids, which were generated by chemical treatments. The differential effects of these chemical treatment experiments also indicated that CPV has a significantly stronger structural integrity than other dsRNA viruses, such as the orthoreovirus subcores, which are normally enclosed within outer protein shells. ^ Finally, we have reconstructed the intact CPV to an unprecendented 8 Å resolution from several thousand of 400kV cryoEM images. The 8 Å structure reveals interactions among the 120 molecules of each of the capsid shell protein (CSP), the large protrusion protein (LPP), and 60 molecules of the turret protein (TP). A total of 1980 α-helices and 720 β-sheets have been identified in these capsid proteins. The CSP structure is largely conserved, with the majority of the secondary structures homologous to those observed in the x-ray structures of corresponding proteins of other reoviruses, such as orthoreovirus and bluetongue virus. The three domains of TP are well positioned to play multifunctional roles during viral transcription. The completely non-equivalent interactions between LPP and CSP and those between the anchoring domain of TP and CSP account for the unparalleled stability of this structurally simplest member of the Reoviridae. ^

Tecnologías de conservación por métodos combinados en pimiento, chaucha y berenjena

La tecnología de los métodos combinados permite reducir la intensidad del tratamiento térmico y mantener las propiedades organolépticas en el producto final, mediante una combinación de obstáculos que aseguran la estabilidad y seguridad microbiana. El objetivo de este trabajo fue aplicar dicha tecnología en la conservación de tres hortalizas: pimiento, chaucha y berenjena y analizar la calidad y vida útil de los productos obtenidos. La elaboración de las conservas se efectuó del siguiente modo: las hortalizas fueron cortadas y posteriormente escaldadas en solución de ácidos cítrico, láctico y acético. Terminada esta etapa se envasaron con la solución de relleno, constituida por los ácidos de la solución de escaldado con la adición de ácido ascórbico. Los análisis que se realizaron tanto en el material fresco como en los productos procesados fueron: humedad, pH, hidratos de carbono, lípidos, proteína, vitamina C, °Brix, actividad enzimática y acidez total. En los productos ya procesados se realizó el control microbiológico. Los resultados indican que la aplicación de los métodos combinados permite conservar los productos elaborados a temperatura ambiente y se mantiene su seguridad microbiológica.