13 results
Interfaces between Biological Theory of Human Development and DIR/Floortime in the understanding and treatment of autism
- P. M. Pacheco, M. D. S. Pacheco, D. R. Molini-Avejonas
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S741-S742
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Introduction
Autism can be described as a mental disorder that displays social interactions and communication impairments as well as a restricted range of activities or interests. Since autism is different for each individual, possible treatments are challenging and should consider individual characteristics at all times. Interactions with peers, family, and teachers are challenging for those with autism as they usually lack behaviors such as eye contact, playing, and talking with other people. It is common to observe sensorial issues as hypersensitivity in these individuals. Patients may have visual, auditive, or even tactile dysfunctions.
Dir/Floortime is a comprehensive model that gives theoretical support and methodological approach to lead to development focusing on the development of individual capacities for sensorial organization, motor planning, language, and many abilities that provide a development trail that will help individuals to achieve essential milestones to infants and adolescents. The DIR/Floortime is based on the development as a lifespan event, individual differences, and relationships established with peers and any other people in the child´s context.
ObjectivesThe aim of this study was to demonstrate that the DIR/Floortime is a comprehensive method of study and intervention since it matches all necessary characteristics to produce development.
MethodsIt was performed a theoretic approach of both DIR/Floortime and Biological Theory of Human Development in search of basis in a contextualist theory to explain a practical method of intervention.
ResultsPsychological theories about human development are important tools for understanding the way individuals interact with their context and produce changes in biopsychosocial characteristics. The Bioecological theory of Human Development is a contextualist theory that considers the interactions established between individuals through a model called PPCT, with their characteristics with people, objects, and symbols through interactions known as proximal processes, considered to be meaningful interactions, occurring frequently, through a long time.
ConclusionsThe TBDH through the PPCT model can show that the DIR/Floortime presented itself as an efficient method for the treatment of autism since it considers the personal characteristics of the patients, especially their sensory and motor characteristics (Personal Characteristics such as Resource, Demand, and Force). This method has in significant interaction the most efficient way to produce development (equivalent to proximal Proximal Processes), takes into account the contexts where the developing individual attends, especially home, school and therapy, and has time as an essential factor for development to occur.
Disclosure of InterestNone Declared
Stressful events among adolescents from public schools in a community in Brazil
- P. M. Pacheco, M. D. S. Pacheco, D. R. Molini-Avejonas
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S907
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Introduction
Adolescence can be seen as a fundamental stage of life for the construction of the subject, resulting from childhood experiences and decisive for adulthood. It is common stressors to appear during adolescence, due to the lack of necessary resources to deal with a stressful problem or event. In this way, the evaluation of a stressful situation by the adolescent is important, because from it he will develop coping strategies that will help him to deal with the problem.
Stressful life experiences, whether important events or even common annoyances, threaten the adolescent’s well-being, in addition to being linked to mental health and behavior problems, both internalizing ones, such as isolation, somatic complaints and anxiety/depression, as well as externalizing factors such as breaking rules and aggressive behavior. Romantic relationships are related to a major source of stress in the lives of these young people when conflicts, jealousy, aggression and infidelity occur, and have a great impact on the mental health of the individuals involved. Breakups, for example, have been linked to the onset of clinical depression in adolescents.
There are three categories of concern for adolescents: (a) related to achievements, such as success in school or opportunity for success in the future; (b) relationships with colleagues or family members; and (c) social problems such as the environment, poverty and unemployment.
ObjectivesTo identify and describe stressful life events in adolescents from public schools in a poor community in Brazil.
MethodsThe study included 64 adolescents, boys (51.56%) and girls (48.43%), aged between 12 and 16 years old (average 13.76%). The Adolescent Perceived Events Scale (APES) was used, which consists of 90 items that correspond to events that may occur in the adolescent’s daily life.
ResultsThe most significant stressors for the adolescents in this study were those dealing with the death of close people, such as a friend (100%), a family member (96.29%) and a relative (94.73%). Also appearing as major stressors were “plans that did not work” (91.89%), use of alcohol or drugs by family members (87.5%), loss of a job by parents (75%), imprisonment of a family member (75%), fights with boyfriend or girlfriend (86.66%), breakup (75%) and concern about their own appearance (76.52%).
ConclusionsEvents referring to interpersonal relationships were considered the greatest stressors, with percentages above 80%. The present study contributed to the understanding of adolescents’ perceptions of their life events. In this way, we can understand the relationship between stressors and the coping strategies. Furthermore, it allows the proposition of preventive intervention strategies in the school context.
Disclosure of InterestNone Declared
Social and affective support network for public school students experiencing learning problems
- P. M. Pacheco, D. R. Molini-Avejonas, M. D. S. Pacheco
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S740-S741
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Introduction
Adolescence presents itself as a phase of life marked by rapid changes produced by different social contexts and in many cases, it can be configured in a stressful situation. The development of a psychosocial support network is of fundamental importance for adolescents to cope with the pressures of life in challenging situations. Many students, especially living in poor communities, face school problems especially because the curriculum fails to provide relevant knowledge to students in a way it can be meaningful and easier to be taught by teachers and learned by students. When students fail at school usually, they tend to blame themselves and as a result they may develop anxiety, social isolation and even depression.
ObjectivesThrough the Bioecological Theory of Human Development, we sought to understand the psychosocial support networks of adolescents, whether or not experiencing school problems, considering this to be a challenging event.
MethodsIn this research it was used the Five Fields Map, an instrument that evaluated the psychosocial support network for adolescents. The students with and without school problems filled the map in the beginning of the year and then at the end of the same year while facing a school problem as repeating the whole year because of insufficient grades.
ResultsThe number of relationships between students facing and not facing school problems was not different, however, failing students had fewer relationships in the school-church Mesosystem, fewer relationships in the second and third levels in the first and second moments of data collection, and more relationships in level 5 in the second moment.
School Home Church Public spaces Rel. Factor Rel. Factor Rel. Factor Rel. Factor Control Beginning 56 5,2 36 4,97 33 6,3 26 6,77 Control End 42 5,26 33 4,94 38 6,6 20 6,7 Total 98 5,23 69 4,97 71 6,45 46 6,74 School problem Beginning 57 5,52 39 5,36 10 6,3 15 5,26 School Problem End 45 5,4 31 5,67 10 6,3 10 5,6 Total 102 5,47 70 5,51 20 6,3 25 5,53 TOTAL 200 5,3 139 5,23 91 6,37 71 6,06 ConclusionsBoth group of students showed great strength of proximity in their psychosocial support networks, indicating that it provided sufficient support so that the outcome of the failure experience was positive.
Disclosure of InterestNone Declared
Analysis of the individual profile of children in Autism Spectrum Disorder (ASD) and therapeutic strategies in the DIR/Floortime model
- P. M. Pacheco, P. Piacentini, M. D. S. Pacheco, D. R. Molini-Avejonas
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S741
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Introduction
Children with Autism Spectrum Disorder (ASD) have a qualitative deficit in social interaction, engagement, and behavior. The DIR/Floortime model is one of the ways of intervention and is based on the child’s Functional Development, Individual differences, and Relationships. It aims to build the foundation for the social, emotional, and intellectual skills of children, instead of having the focus only on isolated behaviors. The model was developed by Stanley Greenspan and Serena Wieder in the United States and is the result of many years of observations and studies on child development since the 1950s. In the 1980s, they unified knowledge from several related studies on child development and mental health and recognized the importance of relationships and affection for learning. One of the considerations of the DIR/Floortime model on children with autism is the individual profile, that is, their individual differences (the I of the DIR). Each child has a unique way of perceiving the world (sight, sounds, touch) and responding to it. They may have difficulties in processing or responding to sensory information. Their individual differences need to be well known so that we can draw up a therapeutic plan to obtain the best developmental evolution.
ObjectivesRecognize and analyze the individual differences of each child, so that the appropriate therapeutic plan can be traced for the development of their potential.
MethodsParticipated in the study 63 children with ASD, 12 girls (19%) and 51 boys (81%). Global Development Assessment questionnaires were used, based on the FEDC and the FEAS scale of the DIR/Floortime.
ResultsAll 63 children presented sensory alterations such as proprioceptive, visual, and vestibular search or hyper-reactivity, directly impacting abilities such as visuospatial processing and motor planning. In addition, 85% of children have low body tone. Regarding the sensory need for visual search, presented by 86% of the children, as well as the vestibular (90%), a recommended therapeutic strategy is mapping the place, with fewer objects. The therapist needs to be in a fixed position and maintain a pleasant, lower tone of voice. The routine framework for motor and action planning, anticipating, and giving the necessary waiting time for the child to get organized. Motor circuits can also help to work with the tone, as well as with praxis.
ConclusionsThe DIR/Floortime model aims to make the child develop the ability to interact meaningfully and connect with the outside world. The individual differences of the child need to be known so that this work can take place effectively and so that the therapist can better organize the therapy, providing the best development for the child.
Disclosure of InterestNone Declared
In situ and in vitro techniques for estimating degradation parameters and digestibility of diets based on maize or sorghum
- B. C. Silva, M. V. C. Pacheco, L. A. Godoi, F. A. S. Silva, D. Zanetti, A. C. B. Menezes, P. Pucetti, S. A. Santos, M. F. Paulino, S. C. Valadares Filho
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- The Journal of Agricultural Science / Volume 158 / Issue 1-2 / March 2020
- Published online by Cambridge University Press:
- 22 April 2020, pp. 150-158
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An experiment was conducted to evaluate: (1) the effects of ensiling maize or sorghum grains after reconstitution on readily soluble fraction (a), potentially degradable fraction in the rumen (b) and rate constant for degradation of b (c) of dry matter (DM), organic matter (OM) and starch (STA); and (2) an appropriate incubation time for in situ or in vitro procedures to estimate in vivo digestibility. Four rumen-cannulated Nellore bulls (body weight = 262 ± 19.6 kg) distributed in a 4 × 4 Latin square were used. Diets were based on dry ground maize (DGM); or dry ground sorghum (DGS); or reconstituted ground maize silage; or reconstituted ground sorghum silage. In vitro and in situ incubations of the individual grains and diets were simultaneously performed with in vivo digestibility. In general, reconstituted grains and diets based on reconstituted grains presented greater (P < 0.05) fraction a and lower (P < 0.05) fraction b of DM, OM and STA compared to dry grains and diets based on dry grain. However, the magnitude of response of the reconstitution and ensiling process on DM and OM degradability parameter was greater for maize than that for sorghum. Moreover, no differences (P > 0.05) were observed between DGM- and DGS-based diets for c estimates. The results suggest that the reconstitution process promotes grains protein matrix breakdown increasing STA availability. The incubation times required for in vivo digestibility estimations of DM, OM and STA are 24 h for in situ and 36 h for in vitro procedures.
Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas
- M. Castillo-Umaña, O. Balocchi, R. Pulido, P. Sepúlveda-Varas, D. Pacheco, S. Muetzel, R. Berthiaume, J. P. Keim
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Forage brassicas, such as summer turnip (ST; Brassica rapa) and forage rape (FR; Brassica napus), are used as supplementary crops during summer. However, studies with lactating dairy cows fed these forages are limited and report inconsistent productive responses. The aim of this study was to determine dry matter intake, rumen fermentation and milk production responses of dairy cows in mid-lactation supplemented with and without summer (‘ST’ or ‘FR’) brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 × 3 Latin square design balanced for residual effects over three 21-day periods. The control diet consisted of 16.2 kg DM of grass silage, 2.25 kg DM of commercial concentrate and 2.25 kg DM solvent-extracted soybean meal. For the other two dietary treatments, 25% of the amounts of silage and concentrates were replaced with FR or ST. The inclusion of forage brassicas had no effects on milk production (24.2 kg cow/day average) and composition (average milk fat and protein 43.2 and 33.6 g/l, respectively). Dry matter intake was 0.98 kg and 1.12 kg lower for cows supplemented with FR and ST, respectively, resulting in a greater feed conversion efficiency (1.35 kg milk/kg DM for ST and FR v. 1.27 kg milk/kg DM for the control diet). Intraruminal pH was lower for cows supplemented with ST compared to the control diet; however, it did not decrease below pH 5.8 at any time of the day. After feeding, the concentrations of total short-chain fatty acids (SCFAs) in rumen contents increased with ST supplementation compared to the control diet. Inclusion of FR in the diet increased the molar proportion of acetate (68.5 mmol/100 mmol) in total SCFA at the expense of propionate, measured 6 h after feeding of the forage. The molar proportion of butyric acid was greater with ST and FR supplementation (13.1 and 12 mmol/100 mmol, respectively) than in control cows. The estimated microbial nitrogen (N) flow was 89.1 g/day greater when supplementing FR compared to the control diet. Based on the haematological measures, the inclusion of summer brassica forages did not affect the health status of the animals. These results indicate that mid-lactation dairy cows fed brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilization.
Temporal fermentation and microbial community dynamics in rumens of sheep grazing a ryegrass-based pasture offered either in the morning or in the afternoon
- R. E. Vibart, S. Ganesh, M. R. Kirk, S. Kittelmann, S. C. Leahy, P. H. Janssen, D. Pacheco
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Eight ruminally-fistulated wethers were used to examine the temporal effects of afternoon (PM; 1600h) v. morning (AM; 0800 h) allocation of fresh spring herbage from a perennial ryegrass (Lolium perenne L.)-based pasture on fermentation and microbial community dynamics. Herbage chemical composition was minimally affected by time of allocation, but daily mean ammonia concentrations were greater for the PM group. The 24-h pattern of ruminal fermentation (i.e. time of sampling relative to time of allocation), however, varied considerably for all fermentation variables (P⩽0.001). Most notably amongst ruminal fermentation characteristics, ammonia concentrations showed a substantial temporal variation; concentrations of ammonia were 1.7-, 2.0- and 2.2-fold greater in rumens of PM wethers at 4, 6 and 8h after allocation, respectively, compared with AM wethers. The relative abundances of archaeal and ciliate protozoal taxa were similar across allocation groups. In contrast, the relative abundances of members of the rumen bacterial community, like Prevotella 1 (P=0.04), Bacteroidales RF16 group (P=0.005) and Fibrobacter spp. (P=0.008) were greater for the AM group, whereas the relative abundance of Kandleria spp. was greater (P=0.04) for the PM group. Of these taxa, only Prevotella 1 (P=0.04) and Kandleria (P<0.001) showed a significant interaction between time of allocation and time of sampling relative to feed allocation. Relative abundances of Prevotella 1 were greater at 2h (P=0.05), 4h (P=0.003) and 6h (P=0.01) after AM allocation of new herbage, whereas relative abundances of Kandleria were greater at 2h (P=0.003) and 4h (P<0.001) after PM allocation. The early post-allocation rise in ammonia concentrations in PM rumens occurred simultaneously with sharp increases in the relative abundance of Kandleria spp. and with a decline in the relative abundance of Prevotella. All measures of fermentation and most microbial community composition data showed highly dynamic changes in concentrations and genus abundances, respectively, with substantial temporal changes occurring within the first 8h of allocating a new strip of herbage. The dynamic changes in the relative abundances of certain bacterial groups, in synchrony with a substantial diurnal variation in ammonia concentrations, has potential effects on the efficiency by which N is utilised by the grazing ruminant.
The AusBeef model for beef production: II. sensitivity analysis
- H. C. DOUGHERTY, E. KEBREAB, M. EVERED, B. A. LITTLE, A. B. INGHAM, J. V. NOLAN, R. S. HEGARTY, D. PACHECO, M. J. MCPHEE
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- The Journal of Agricultural Science / Volume 155 / Issue 9 / November 2017
- Published online by Cambridge University Press:
- 03 August 2017, pp. 1459-1474
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The present study evaluated the behaviour of the AusBeef model for beef production as part of a 2 × 2 study simulating performance on forage-based and concentrate-based diets from Oceania and North America for four methane (CH4)-relevant outputs of interest. Three sensitivity analysis methods, one local and two global, were conducted. Different patterns of sensitivity were observed between forage-based and concentrate-based diets, but patterns were consistent within diet types. For the local analysis, 36, 196, 47 and 8 out of 305 model parameters had normalized sensitivities of 0, >0, >0·01 and >0·1 across all diets and outputs, respectively. No parameters had a normalized local sensitivity >1 across all diets and outputs. However, daily CH4 production had the greatest number of parameters with normalized local sensitivities >1 for each individual diet. Parameters that were highly sensitive for global and local analyses across the range of diets and outputs examined included terms involved in microbial growth, volatile fatty acid (VFA) yields, maximum absorption rates and their inhibition due to pH effects and particle exit rates. Global sensitivity analysis I showed the high sensitivity of forage-based diets to lipid entering the rumen, which may be a result of the use of a feedlot-optimized model to represent high-forage diets and warrants further investigation. Global sensitivity analysis II showed that when all parameter values were simultaneously varied within ±10% of initial value, >96% of output values were within ±20% of the baseline, which decreased to >50% when parameter value boundaries were expanded to ±25% of their original values, giving a range for robustness of model outputs with regards to potential different ‘true’ parameter values. There were output-specific differences in sensitivity, where outputs that had greater maximum local sensitivities displayed greater degrees of non-linear interaction in global sensitivity analysis I and less variance in output values for global sensitivity analysis II. For outputs with less interaction, such as the acetate : propionate ratio and microbial protein production, the single most sensitive term in global sensitivity analysis I contributed more to the overall total-order sensitivity than for outputs with more interaction, with an average of 49, 33, 15 and 14% of total-order sensitivity for microbial protein production, acetate : propionate ratio, CH4 production and energy from absorbed VFAs, respectively. Future studies should include data collection for highly sensitive parameters reported in the present study to improve overall model accuracy.
The AusBeef model for beef production: I. Description and evaluation
- H. C. DOUGHERTY, E. KEBREAB, M. EVERED, B. A. LITTLE, A. B. INGHAM, R. S. HEGARTY, D. PACHECO, M. J. MCPHEE
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- The Journal of Agricultural Science / Volume 155 / Issue 9 / November 2017
- Published online by Cambridge University Press:
- 03 August 2017, pp. 1442-1458
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As demand for animal products, such as meat and milk, increases, and concern over environmental impact grows, mechanistic models can be useful tools to better represent and understand ruminant systems and evaluate mitigation options to reduce greenhouse gas emissions without compromising productivity. The objectives of the present study were to describe the representation of processes for growth and enteric methane (CH4) production in AusBeef, a whole-animal, dynamic, mechanistic model for beef production; evaluate AusBeef for its ability to predict daily methane production (DMP, g/day), gross energy intake (GEI, MJ/day) and methane yield (MJ CH4/MJ GEI) using an independent data set; and to compare AusBeef estimates to those from the empirical equations featured in the current National Academies of Sciences, Engineering and Medicine (NASEM, 2016) beef cattle requirements for growth and the Ruminant Nutrition System (RNS), a dynamic, mechanistic model of Tedeschi & Fox, 2016. AusBeef incorporates a unique fermentation stoichiometry that represents four microbial groups: protozoa, amylolytic bacteria, cellulolytic bacteria and lactate-utilizing bacteria. AusBeef also accounts for the effects of ruminal pH on microbial degradation of feed particles. Methane emissions are calculated from net ruminal hydrogen balance, which is defined as the difference between inputs from fermentation and outputs due to microbial use and biohydrogenation. AusBeef performed similarly to the NASEM empirical model in terms of prediction accuracy and error decomposition, and with less root mean square predicted error (RMSPE) than the RNS mechanistic model when expressed as a percentage of the observed mean (RMSPE, %), and the majority of error was non-systematic. For DMP, RMSPE for AusBeef, NASEM and RNS were 24·0, 19·8 and 50·0 g/day for the full data set (n = 35); 25·6, 18·2 and 56·2 g/day for forage diets (n = 19); and 21·8, 21·5 and 41·5 g/day for mixed diets (n = 16), respectively. Concordance correlation coefficients (CCC) were highest for GEI, with all models having CCC > 0·66, and higher CCC for forage diets than mixed, while CCC were lowest for MY, particularly forage diets. Systematic error increased for all models on forage diets, largely due to an increase in error due to mean bias, and while all models performed well for mixed diets, further refinements are required to improve the prediction of CH4 on forage diets.
Contributors
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- By Victoria M. Allen, Frederic Amant, Sarah Armstrong, Thomas F. Baskett, Michael A. Belfort, Meredith Birsner, Renee D. Boss, Leanne Bricker, Josaphat K. Byamugisha, Giorgio Capogna, Michael P. Casaer, Frank A. Chervenak, Vicki Clark, Filip Claus, Malachy O. Columb, Charles Cox, Jean T. Cox, Vegard Dahl, John Davison, Jan Deprest, Clifford S. Deutschman, Roland Devlieger, Karim Djekidel, Steven Dymarkowski, Roshan Fernando, Clare Fitzpatrick, Sreedhar Gaddipati, Thierry Girard, Emily Gordon, Ian A. Greer, David Grooms, Sina Haeri, Katy Harrison, Edward J. Hayes, Michelle Hladunewich, Andra H. James, Tracey Johnston, Bellal Joseph, Erin Keely, Ruth Landau, Stephen E. Lapinsky, Susanna I. Lee, Larry Leeman, Hennie Lombaard, Stephen Lu, Alison MacArthur, Laura A. Magee, Paul E. Marik, Laurence B. McCullough, Alexandre Mignon, Carlo Missant, Jack Moodley, Lisa E. Moore, Kate Morse, Warwick D. Ngan Kee, Catherine Nelson-Piercy, Clemens M. Ortner, Geraldine O’Sullivan, Luis D. Pacheco, Fathima Paruk, Melina Pectasides, Nigel Pereira, Patricia Peticca, Sharon T. Phelan, Felicity Plaat, Lauren A. Plante, Michael P. Plevyak, Dianne Plews, Wendy Pollock, Laura C. Price, Peter Rhee, Leiv Arne Rosseland, Kathryn M. Rowan, Helen Ryan, Helen Scholefield, Neil S. Seligman, Nadir Sharawi, Alex Sia, Bob Silver, Mieke Soens, Ulrich J. Spreng, Silvia Stirparo, Nova Szoka, Andrew Tang, Kha M. Tran, Els Troost, Lawrence C. Tsen, Derek Tuffnell, Kristel Van Calsteren, Marc Van de Velde, Marcel Vercauteren, Chris Verslype, Peter von Dadelszen, Carl Waldman, Michelle Walters, Linda Watkins, Paul Westhead, Cynthia A. Wong, Gerda G. Zeeman, Joost J. Zwart
- Edited by Marc van de Velde, Helen Scholefield, Lauren A. Plante
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- Maternal Critical Care
- Published online:
- 05 July 2013
- Print publication:
- 04 July 2013, pp ix-xiv
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- By Krista Adamek, Ana Luisa K. Albernaz, J. Marcio Ayres†, Andrew J. Baker, Karen L. Bales, Adrian A. Barnett, Christopher Barton, John M. Bates, Jennie Becker, Bruna M. Bezerra, Júlio César Bicca-Marques, Richard Bodmer, Jean P. Boubli, Mark Bowler, Sarah A. Boyle, Christini Barbosa Caselli, Janice Chism, Elena P. Cunningham, José Maria C. da Silva, Lesa C. Davies, Nayara de Alcântara Cardoso, Manuella A. de Souza, Stella de la Torre, Ana Gabriela de Luna, Thomas R. Defler, Anthony Di Fiore, Eduardo Fernandez-Duque, Stephen F. Ferrari, Wilsea M.B. Figueiredo-Ready, Tracy Frampton, Paul A. Garber, Brian W. Grafton, L. Tremaine Gregory, Maria L. Harada, Amy Harrison-Levine, Walter C. Hartwig, Stefanie Heiduck, Eckhard W. Heymann, André Hirsch, Leandro Jerusalinsky, Gareth Jones, Richard F. Kay, Martin M. Kowalewski, Shawn M. Lehman, Laura Marsh, Jesús Martinez, William A. Mason, Hope Matthews, Wynlyn McBride, Shona McCann-Wood, W. Scott McGraw, D. Jeffrey Meldrum, Sally P. Mendoza, Nohelia Mercado, Russell A. Mittermeier, Mirjam N. Nadjafzadeh, Marilyn A. Norconk, Robert Gary Norman, Marcela Oliveira, Marcelo M. Oliveira, Maria Juliana Ospina Rodríguez, Erwin Palacios, Suzanne Palminteri, Liliam P. Pinto, Marcio Port-Carvalho, Leila Porter, Carlos Portillo-Quintero, George Powell, Ghillean T. Prance, Rodrigo C. Printes, Pablo Puertas, P. Kirsten Pullen, Helder L. Queiroz, Luis Reginaldo R. Rodrigues, Adriana Rodríguez, Alfred L. Rosenberger, Anthony B. Rylands, Ricardo R. Santos, Horacio Schneider, Eleonore Z.F. Setz, Suleima S.B. Silva, José S. Silva Júnior, Andrew T. Smith, Marcelo C. Sousa, Antonio S. Souto, Wilson R. Spironello, Masanaru Takai, Marcelo F. Tejedor, Cynthia L. Thompson, Diego G. Tirira, Raul Tupayachi, Bernardo Urbani, Liza M. Veiga, Marianela Velilla, João Valsecchi, Jean-Christophe Vié, Tatiana M. Vieira, Suzanne E. Walker-Pacheco, Rob Wallace, Patricia C. Wright, Charles E. Zartman
- Edited by Liza M. Veiga, Universidade Federal do Pará, Brazil, Adrian A. Barnett, Roehampton University, London, Stephen F. Ferrari, Universidade Federal de Sergipe, Brazil, Marilyn A. Norconk, Kent State University, Ohio
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- Evolutionary Biology and Conservation of Titis, Sakis and Uacaris
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- 05 April 2013
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- 11 April 2013, pp xii-xv
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Deriving fractional rate of degradation of logistic-exponential (LE) model to evaluate early in vitro fermentation
- M. Wang, X. Z. Sun, S. X. Tang, Z. L. Tan, D. Pacheco
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Water-soluble components of feedstuffs are mainly utilized during the early phase of microbial fermentation, which could be deemed an important determinant of gas production behavior in vitro. Many studies proposed that the fractional rate of degradation (FRD) estimated by fitting gas production curves to mathematical models might be used to characterize the early incubation for in vitro systems. In this study, the mathematical concept of FRD was developed on the basis of the Logistic-Exponential (LE) model, with initial gas volume being zero (LE0). The FRD of the LE0 model exhibits a continuous increase from initial (FRD0) toward final asymptotic value (FRDF) with longer incubation time. The relationships between the FRD and gas production at incubation times 2, 4, 6, 8, 12 and 24 h were compared for four models, in addition to LE0, Generalization of the Mitscherlich (GM), cth order Michaelis–Menten (MM) and Exponential with a discrete LAG (EXPLAG). A total of 94 in vitro gas curves from four subsets with a wide range of feedstuffs from different laboratories and incubation periods were used for model testing. Results indicated that compared with the GM, MM and EXPLAG models, the FRD of LE0 model consistently had stronger correlations with gas production across the four subsets, especially at incubation times 2, 4, 6, 8 and 12 h. Thus, the LE0 model was deemed to provide a better representation of the early fermentation rates. Furthermore, the FRD0 also exhibited strong correlations (P < 0.05) with gas production at early incubation times 2, 4, 6 and 8 h across all four subsets. In summary, the FRD of LE0 model provides an alternative to quantify the rate of early stage incubation, and its initial value could be an important starting parameter of rate.
Stellar and Circumstellar Activity in the Be Star EW Lac from the Multi-site 1993 Campaign
- A.M. Hubert, M. Floquet, R. Hirata, D. McDavid, J. Zorec, D. Gies, M. Hahula, E. Janot-Pacheco, E. Kambe, N.V. Leister, S. Stefl, A. Tarasov
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- International Astronomical Union Colloquium / Volume 175 / 2000
- Published online by Cambridge University Press:
- 12 April 2016, pp. 550-553
- Print publication:
- 2000
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The Be shell star EW Lac was observed in September 1993 during a multi-site campaign. Results from visual spectroscopy and polarimetry are summarized here. He I 6678 profiles have been compared to previous observations held in 1989 and show an additional complex and highly variable circumstellar component which can due to material expelled from the star just prior to these observations. Two groups of frequencies are found again in 1993 observations compared with 1989 ones. In the frame of nrp, they could be associated to low degree g-modes.