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Sample records for caloric tests

  1. Caloric testing by continuous automatic alternating irrigation.

    Science.gov (United States)

    Reker, U

    1980-01-01

    Quantitative caloric test results show a high variability. They were described as questionable by Frenzel (1955) and a review of the test was recommended by Hood (1973). Thus, we developed a new method: continuous automatic alternating irrigation. An irrigator is connected to two water-baths of 30 degrees C and 44 degrees C. A time-relays switches over from one bath to the other every 60 s. The continuous, but alternating, irrigations produce subsequently alternating exponential temperature waves in the temporal bone. The mathematical model shows a quasi-periodicity and sufficient symmetry of the alternating thermal gradient across the canal, except for the first stimulus. After 11 irrigations of 60 s, a short (20 s) "washout" irrigation terminates the sequence. By the five repetitions of each stimulus and the additional possibility of correlating the response to the paper-marked stimulus periodicity the judgement is far more reliable and therefore, in doubtful cases, despite the five-fold data, quicker. The technical device is simple enough for routine use and inexpensive. The results of the caloric test are now much more clear-cut and the correlation to a known clinical pathology is remarkably high.

  2. Analysis of caloric test responses in sudden hearing loss.

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    Shih, Cheng-Ping; Chou, Yu-Ching; Chen, Hsin-Chien; Lee, Jih-Chin; Chu, Yueng-Hsiang; Wang, Chih-Hung

    2017-02-01

    Sudden sensorineural hearing loss is characterized by a rapid-onset hearing loss that develops within 3 days. Vertigo may also be present. We conducted a retrospective study to investigate whether the severity of a loss of caloric function is associated with the initial hearing loss and with hearing recovery. Our study population was made up of 135 patients-67 men and 68 women, aged 25 to 71 years (mean: 50.9)-with sudden sensorineural hearing loss who had undergone bithermal caloric testing. We compared various patient factors according to patients' hearing level and their response to caloric testing. We also analyzed the canal paresis (CP) value in patients with an abnormal caloric response according to three factors: disease severity, vertigo, and hearing recovery, and we evaluated the correlation between the loss of caloric function and hearing outcomes. We found that an abnormal caloric response was significantly associated with a profound hearing loss at presentation, the presence of vertigo, and poor hearing recovery. Among patients with an abnormal caloric response, the CP value was significantly correlated with hearing recovery (r = 0.503, p = 0.001). Poor hearing recovery was seen in 80% of patients with a CP value of ≥40% but in only 25% of patients with a value of hearing recovery was worse in the patients with a CP value of ≥40% (p = 0.002). We conclude that a CP value of ≥40% is a significant prognostic factor for an unfavorable treatment outcome.

  3. Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints

    Science.gov (United States)

    Mezzalira, Raquel; Bittar, Roseli Saraiva Moreira; do Carmo Bilécki-Stipsky, Marcia Maria; Brugnera, Cibele; Grasel, Signe Schuster

    2017-01-01

    OBJECTIVE: This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. METHODS: A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. RESULTS: Significantly more caloric test results than video head impulse test results were abnormal. CONCLUSIONS: The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints. PMID:28954005

  4. Video head-impulse test (vHIT) in dizzy children with normal caloric responses.

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    Khater, Ahmed Mohammed; Afifi, Pretty O

    2016-08-01

    The caloric test and the video head-impulse test are diagnostic tools to examine dizzy patients through assessing the function of the semicircular canals. There are major differences between the two tests as regards stimulus characteristics, methodology, and function examined. The aim of this study is to evaluate the results of vHIT in children and adolescents with normal caloric test. This work was performed on 63 patients, but 14 were excluded because of technical problems in the caloric test. So, this is a prospective work in 49 patients (27 females and 22 males) with different types of vestibular disease seen because of vertigo in which both procedures were performed the same day. The caloric test was performed with air at two different temperatures in which both ears were irrigated alternately. Then, the video head-impulse test was carried out. Main outcome measures were the gain of vestibulo-ocular reflex, gain asymmetry, and refixation saccades in the vHIT. in all studied cases, caloric test was normal. The mean age of patients was 16 years. By vHIT, in 8 patients (16%) no abnormality was detected, while abnormal findings were found in 41 patients. Single canal affection was seen in 29 patients whereas 12 patients had combined canal affection. The right side was affected in 27 and left side in 22 patients. In single canal affection, isolated horizontal canals were affected in 4, anterior canals in 5 and posterior canals in 20 patients. While in combined canal affection, the affection is seen in the same ear. Moreover the most common pattern seen is affection of left anterior and left posterior canals. The caloric and vHIT is very important tests in diagnosis of dizzy patients. The information from both methods is redundant in some cases but complementary in most. vHIT is a "child friendly," relatively easy-to-use, and simple tool to evaluate each of the 6 semicircular canals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Comparison of caloric and head-impulse tests during the attacks of Meniere's disease.

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    Lee, Sun-Uk; Kim, Hyo-Jung; Koo, Ja-Won; Kim, Ji-Soo

    2017-03-01

    To aid in diagnosis of Meniere's disease (MD) during the attacks using caloric and head-impulse tests (HITs). Retrospective case series review. We analyzed the results of bithermal caloric and HITs during the attacks in 16 patients with MD. Quantitative analyses of HITs were conducted using a magnetic search coil technique. In unilateral MD (14 patients, 42 semicircular canals), the head impulse gain of the vestibulo-ocular reflex (VOR) was either normal (28 of 42, 67%), decreased (8 of 42, 19%), or increased (6 of 42, 14%) for each semicircular canal in the affected ear. Likewise, the head impulse VOR gain was either normal (29 of 42, 69%), increased (11 of 42, 26%), or decreased (2 of 42, 5%) in the intact ear. The VOR gain for the horizontal canal was significantly lower on the affected side (P = 0.013). However, the VOR gains for the anterior and posterior canals did not differ between the sides (P = 0.270, P = 0.282). In bilateral MD (two patients, 12 semicircular canals), the VOR gain was either decreased (6 of 12, 50%) or normal (6 of 12, 50%) in either ear. In contrast, the caloric responses were usually decreased in the affected ear (7 of 11, 64%, including one with bilateral MD). During the attacks of MD, HITs showed varied results between the ears and among the canals, although the caloric responses were usually decreased in the involved ear. These dissociations suggest a frequency-dependent impairment of canal function or mechanical property of the endolymphatic hydrops during the attacks of MD. 4. Laryngoscope, 127:702-708, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. The minimal caloric test asymmetric response in vertigo-free migraine patients

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    Eliana Teixeira Maranhão

    2016-02-01

    Full Text Available ABSTRACT Vertigo symptoms and subclinical vestibular dysfunctions may occur in migraine. The Minimal Caloric Test (MCT, an easy-to-perform, convenient and yet informative procedure was used to test the vestibular function in 30 vertigo-free migraine patients outside attacks and 30 paired controls. Although not statistically significant, a right-to-left nystagmus duration asymmetry greater than 25% was present in both groups. This difference was greater in the patients group, suggesting the presence of subclinical vestibular imbalance in migraine.

  7. Computing simulated endolymphatic flow thermodynamics during the caloric test using normal and hydropic duct models.

    Science.gov (United States)

    Rey-Martinez, Jorge; McGarvie, Leigh; Pérez-Fernández, Nicolás

    2017-03-01

    The obtained simulations support the underlying hypothesis that the hydrostatic caloric drive is dissipated by local convective flow in a hydropic duct. To develop a computerized model to simulate and predict the internal fluid thermodynamic behavior within both normal and hydropic horizontal ducts. This study used a computational fluid dynamics software to simulate the effects of cooling and warming of two geometrical models representing normal and hydropic ducts of one semicircular horizontal canal during 120 s. Temperature maps, vorticity, and velocity fields were successfully obtained to characterize the endolymphatic flow during the caloric test in the developed models. In the normal semicircular canal, a well-defined endolymphatic linear flow was obtained, this flow has an opposite direction depending only on the cooling or warming condition of the simulation. For the hydropic model a non-effective endolymphatic flow was predicted; in this model the velocity and vorticity fields show a non-linear flow, with some vortices formed inside the hydropic duct.

  8. Predictive properties of the video head impulse test: measures of caloric symmetry and self-report dizziness handicap.

    Science.gov (United States)

    McCaslin, Devin L; Jacobson, Gary P; Bennett, Marc L; Gruenwald, Jill M; Green, Andrea P

    2014-01-01

    The purpose of this investigation was to determine whether a predictable relationship existed between self-reported dizziness handicap and video Head Impulse Test (vHIT) results in a large sample of patients reporting to a dizziness clinic. Secondary objectives included describing the characteristics of the vHIT ipsilesional and contralesional vestibulo-ocular reflex slow-phase velocity in patients with varying levels of canal paresis. Finally, the authors calculated the sensitivity and specificity of the vHIT for detecting horizontal semicircular canal impairment using the caloric test as the "gold standard." Participants were 115 adults presenting to a tertiary medical care center with symptoms of dizziness. Participants were administered a measure of self-report dizziness handicap (i.e., Dizziness Handicap Inventory) and underwent caloric testing and vHIT at the same appointment. Results showed that (1) there were no significant group differences (i.e., vHIT normal versus vHIT abnormal) in the Dizziness Handicap Inventory total score, (2) both ipsilesional and contralateral velocity gain decreased with increases in caloric paresis, and (3) a caloric asymmetry of 39.5% was determined to be the cutoff that maximized discrimination of vHIT outcome. The level of self-reported dizziness handicap is not predicted by the outcome of the vHIT, which is consistent with the majority of published reports describing the poor relationship between quantitative tests of vestibular function and dizziness handicap. Further, the study findings have demonstrated that vHIT and caloric data are not redundant, and each test provides unique information regarding the functional integrity of the horizontal semicircular canal at different points on the frequency spectrum. The vHIT does offer some advantages over caloric testing, but at the expense of sensitivity. The vHIT can be completed in less time, is not noxious to the patient, and requires very little laboratory space. However, the

  9. Comparison of Vestibular Evoked Myogenic Potential and Caloric Tests Findings in Noise Induced Hearing Loss-Affected and Healthy Individuals

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    Farinoosh Fakharnia

    2010-06-01

    Full Text Available Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL, based on both vestibular evoked myogenic potentials (VEMP and caloric tests.Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, p13 and n23 latencies, and p13-n23 amplitude. Caloric test was performed only for 20 patients.Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of p13 in the right ear (p=0.003 and left ear (p=0.01 was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03. There was no significant difference between groups in p13-n23 amplitude.Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.

  10. Interpretação e utilidade da prova calórica Interpretation and use of caloric testing

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    Denise Utsch Gonçalves

    2008-06-01

    Full Text Available A prova calórica é o teste da avaliação otoneurológica que verifica a integridade do reflexo vestíbulo-ocular e possibilita avaliar cada labirinto separadamente. Os principais aspectos relacionados à realização, interpretação e utilidade da prova calórica foram revistos. MÉTODOS: Realizou-se revisão sistemática sobre as publicações ocorridas nos últimos cem anos sobre o assunto. Incluíram-se artigos originais transversais e longitudinais, de revisão e meta-análise. Excluíram-se revisões de papeleta, relatos de caso e editoriais. Os descritores utilizados foram: prova calórica, nistagmo, sistema vestibular, preponderância direcional, predomínio labiríntico, teste calórico monotermal, teste calórico com água gelada, fenômeno de Bell. Pesquisou-se as bases de dados COCHRAINE, MEDLINE, LILACS, CAPES. RESULTADOS: De 818 resumos de artigos, selecionou-se inicialmente 93 que preenchiam os critérios de inclusão. A leitura dos artigos resultou na seleção final de 55. Na análise dos artigos, enfatizou-se na discussão fundamentos da prova calórica, tipos de estimulação utilizados, prova calórica monotermal e com água gelada, questões relacionadas à interpretação dos resultados, variáveis e artefatos. COMENTÁRIOS FINAIS: os valores de referência utilizados na prova calórica podem variar de serviço para serviço, com ponto de corte definido a partir de estudos locais. Semiotécnica cuidadosa é fundamental para elevar a sensibilidade do exame.Caloric testing is an otoneurologic evaluation of the status of the vestibular-ocular reflex; it allows an evaluation of each labyrinth separately. The main aspects on the use and interpretation of caloric testing are reviewed. METHOD: A systematic review of papers published in the past one hundred years on caloric testing was undertaken. The inclusion criteria were: cross-sectional, longitudinal, original articles, reviews and meta-analyses. Reviews of patient charts

  11. Comparison of the video head impulse test with the caloric test in patients with sub-acute and chronic vestibular disorders.

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    Burston, Anne; Mossman, Stuart; Mossman, Benjamin; Weatherall, Mark

    2018-01-01

    The aim of this prospective register-based study was to compare video Head Impulse Tests (vHIT) with caloric tests on 173 patients assessed by a tertiary Neurology referral centre who had been referred for investigation of dizziness or vertigo and whose symptom duration was one month or longer. Abnormal vHIT was defined as angular velocity gain (peak eye velocity/peak head velocity) less than 0.79 at 80 ms and 0.75 at 60 ms, which was two standard deviations below our institutions' lower limit of normal; together with refixation saccades. Abnormal bi-thermal caloric testing defined unilateral hypofunction as a 25% difference using Jongkee's formula and bilateral hypofunction was defined by the sum of the peak slow phase velocities over the four irrigations being <20°/s. Sixty patients had abnormal results on one or both tests, of whom 51 had unilateral and nine bilateral hypofunction. With caloric testing considered as the gold standard, the sensitivity (95% CI) of the vHIT was 18/52, 34.6% (22.0-49.1), and the specificity (95% CI) was 113/121, 93.4% (87.4-97.1). However vHIT was more sensitive in the nine patients with bilateral hypofunction with 100% abnormal vHIT results while only 4/9, 44% had abnormal caloric results. In conclusion these results support the continued use of both vHIT and caloric tests in patients with sub-acute and chronic vestibular symptoms, especially if the vHIT is normal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Morphological correlation between caloric tests and vestibular hydrops in Ménière's disease using intravenous Gd enhanced inner ear MRI.

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    Choi, Ji Eun; Kim, Yi-Kyung; Cho, Young Sang; Lee, Kieun; Park, Hyun Woo; Yoon, Sung Hoon; Kim, Hyung-Jin; Chung, Won-Ho

    2017-01-01

    The purpose of this study was to prove the hypothesis that caloric response in Ménière's disease (MD) is reduced by hydropic expansion of the vestibular labyrinth, not by vestibular hypofunction, by evaluating the correlation morphologically using an intravenous Gadolinium (IV-Gd) inner ear MRI. In study I, the prevalence of abnormal video Head Impulse Test (vHIT) results among the patients with definite unilateral MD (n = 24) and vestibular neuritis (VN) (n = 22) were investigated. All patients showed abnormal canal paresis (CP) (> 26%) on caloric tests. The prevalence of abnormal vHIT in patients with abnormal CP was significantly lower in MD patients (12.5%) than that in VN patients (81.8%) (p < 0.001). In study II, morphological correlation between caloric tests and vestibular hydrops level was evaluated in unilateral MD patients (n = 16) who had normal vHIT results. Eleven patients (61%) had abnormal CP. After taking the images of IV-Gd inner ear MRI, the vestibular hydrops ratio (endolymph volume/total lymph volume = %VH) was measured. In addition, the relative vestibular hydrops ratio (%RVH = (%VHaffected ear-%VHunaffected ear) / (%VHaffected ear + %VHunaffected ear)) was calculated. Each ratio (%VH and %RVH) was compared with average peak slow phase velocity (PSPV) and CP, respectively. In the MD patients, %VH of the affected ear correlated significantly with mean PSPV on the same side (rs = -0.569, p = 0.024), while %RVH correlated significantly with CP (rs = 0.602, p = 0.014). In most MD patients (87.5%) compared to VN patients, vHIT results were normal even though the caloric function was reduced. In addition, the reduced caloric function with normal vHIT was related to the severity of the vestibular hydrops measured by the IV-Gd inner ear MRI. These findings concluded that the abnormal caloric tests with normal vHIT in MD indicated severe endolymphatic hydrops rather than vestibular hypofunction.

  13. O estudo da prova calórica em pacientes idoso The study of caloric testing in senior patients

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    Débora Cristina de Oliveira Bezerra

    2008-01-01

    Full Text Available OBJETIVO: realizar o estudo da prova calórica em pacientes idosos com queixa de tontura, acompanhada ou não de zumbido com finalidade de traçar um perfil dos idosos quanto os sintomas vestibulares. MÉTODOS: fizeram parte da amostra 143 pacientes, com faixa etária variando de 60 a 90 anos de idade; todos realizaram o exame otoneurológico. Foram excluídos pacientes idosos com queixa de desequilíbrio e aqueles que apresentaram a queixa de zumbido desacompanhado da tontura. RESULTADOS: o estudo demonstrou que a normorreflexia, em valores absolutos, encontra-se entre 82,3% a 91,2% e os valores relativos são de 93%. Referente aos dados colhidos na anamnese, o que chamou a atenção, foi que do total de pacientes analisados, encontrou-se a tontura acompanhada de zumbido em 69% dos casos e o elevado uso de medicação em pacientes nesta faixa etária. CONCLUSÃO: na população estudada houve um predomínio da tontura acompanhada de zumbido. Em relação à prova calórica, o trabalho demonstrou a alta prevalência de pacientes com valores absolutos e relativos normais.PURPOSE: to accomplish the study of caloric testing in senior patients with dizziness, accompanied or not of with buzzing. METHODS: 143 patients were analyzed with age varying from 60 to 90 years; all of them did an otoneurologic evaluation. Senior patients with unbalance complaints and with buzzing unaccompanied with dizziness were excluded from this study. RESULTS: 82.3% to 91.2% of the patients obtained normoreflexia in absolute values and over 93% obtained normal results in relative values. Referring to the data obtained in the anamnesis, what got attention was 69% of dizziness accompanied with buzzing. And the high medication of the patients in this age group. CONCLUSION: there was a prevalence of dizziness accompanied with buzzing in the studied population. Concerning the caloric testing, the study demonstrated the high prevalence of patients with normal absolute and

  14. Do nistagmo às provas calóricas com ar e com água From nystagmus to the air and water caloric tests

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    Anna Carolina Marques Perrella de Barros

    2012-08-01

    Full Text Available A prova calórica é uma importante ferramenta na avaliação da função labiríntica. OBJETIVO: Comparar o nistagmo pós-calórico da prova com ar a 50ºC e 24ºC com o da prova com água a 44ºC e 30ºC. Desenho científico: Estudo clínico cruzado randomizado. MATERIAL E MÉTODO: 40 indivíduos hígidos submetidos à avaliação da função vestibular incluindo a prova calórica com ar a 50ºC e 24ºC e com água a 44ºC e 30ºC. RESULTADOS: À comparação das provas com ar e com água, não houve diferença significante entre os valores da velocidade angular da componente lenta (VACL do nistagmo pós-calórico quanto à ordem de realização das estimulações, entre as orelhas e entre os valores de predomínio labiríntico e de preponderância direcional. Os valores da VACL foram maiores nas estimulações com água (p = 0,008; p The caloric test is an important tool for the assessment of labyrinthine function. OBJECTIVE: To compare the nystagmus response in the caloric tests with air at 50ºC and 24ºC and with water at 44ºC and 30ºC. Study Design: Randomized crossover clinical trial. MATERIALS AND METHODS: 40 healthy individuals were submitted to a neurotological evaluation, including caloric tests with air at 50ºC and 24ºC and water at 44ºC and 30ºC. RESULTS: Comparing the air and water caloric tests, there were no significant differences among the post-caloric nystagmus slow-phase velocity in relation to the stimulation order, between ears and between the values of unilateral weakness and directional preponderance. The slow-phase velocity values were higher with water (p = 0.008, p < 0.001, and cold stimulation produced stronger responses (p < 0.001. CONCLUSION: Comparing 50ºC and 24ºC air caloric test and 44ºC and 30ºC water caloric test, we observed similar slow-phase velocity values for both ears, higher responses in the cold temperature and in the test with water, and similar results of unilateral weakness or directional

  15. Caloric stimulation

    Science.gov (United States)

    ... hearing and balance. The test also checks for damage to the brain stem. ... eye movements do not occur even after ice cold water is given, there may be damage to the: Nerve of the inner ear Balance ...

  16. Insensitivity of the "Romberg test of standing balance on firm and compliant support surfaces" to the results of caloric and VEMP tests.

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    Jacobson, Gary P; McCaslin, Devin L; Piker, Erin G; Gruenwald, Jill; Grantham, Sarah; Tegel, Lauren

    2011-01-01

    The objective of this study was to assess the sensitivity, specificity, and positive and negative predictive value of the Romberg Test of Standing Balance on Firm and Compliant Support Surfaces (RTSBFCSS) for the identification of patients with vestibular system impairments affecting the horizontal semicircular canal, saccule, and/or inferior and superior vestibular nerves. The RTSBFCSS was developed for the National Health and Nutrition Examination Survey (NHANES) and was used recently to estimate the numbers of individuals aged 40 yr or older with vestibular system impairments among the general population of the United States. A retrospective analysis of the medical records of 103 consecutive patients aged 40 yr or older (mean age 59 ± 12 yr, 71 females) who had undergone vestibular assessment at the Balance Disorders Clinic at the Vanderbilt University School of Medicine. Patients with complete electro- or videonystagmography testing, cervical vestibular evoked myogenic potential (cVEMP) testing, and the RTSBFCSS screening test were included in the analysis. A series of 2 × 2 tables were created that represented the number of "true positives," "true negatives," "false positives," and "false negatives" of the RTSBFCSS under conditions where the caloric test was abnormal and then separately where the cVEMP test was abnormal. The data were analyzed in a manner such that sensitivity, specificity, and both positive and negative predictive value of the RTSBFCSS could be calculated. When the caloric test was used as the criterion standard and the subject selection criteria in the NHANES study were used (i.e., subjects who were able to maintain postural stability for trials 1-3 of the RTSBFCSS; N = 45), the sensitivity and specificity of the RTSBFCSS to impairment of the horizontal semicircular canal or superior vestibular nerve were 55% and 64%, respectively, yielding positive and negative predictive values of 55% and 64%, respectively. When all patients aged 40 yr

  17. Calore e termodinamica

    CERN Document Server

    Zemansky, Mark W

    1970-01-01

    Temperatura ; sistemi termodinamici semplici ; lavoro ; il calore e il primo principio ; gas ideali ; teoria cinetica dei gas ideali ; il secondo principio della termodinamica ; reversibilità e temperatura Kelvin ; entropia ; meccanica statistica sostanze pure ; transizioni di fase, elio liquido ed elio solido ; sistemi particolari ; paramagnetismo, fisica delle basse temperature, temperature negative e terzo principio ; superfluidità e superconduttività ; equilibrio chimico ; reazioni con gas ideali ; sistemi eterogenei.

  18. Estimulação calórica gelada com ar nas vestibulopatias periféricas crônicas com nistagmo espontâneo Ice air caloric test in chronic peripheral vestibular dysfunction with spontaneous nystagmus

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    Flavia Silveira dos Santos Cabral

    2008-01-01

    Full Text Available OBJETIVO: analisar o efeito da estimulação gelada com ar a 10ºC sobre o nistagmo pós-calórico em pacientes com vestibulopatias periféricas crônicas que apresentam nistagmo espontâneo com olhos fechados. MÉTODOS: 61 pacientes foram submetidos às estimulações com ar a 42, 18 e 10ºC. RESULTADOS: em 42 casos (69,8% foram encontrados valores anormais de preponderância direcional e/ou de predomínio labiríntico a 42 e 18ºC. A prova a 10ºC apresentou valores de assimetria dentro dos padrões de normalidade em 52,5% dos casos e valores anormais de assimetria em 16,4% (p=0,012, confirmou hiporreflexia unilateral em 11,5% e identificou anormalidades não evidenciadas a 42 e 18ºC em 8,2%. CONCLUSÃO: a estimulação gelada com ar a 10ºC possibilitou retirar a influência do nistagmo espontâneo de olhos fechados sobre o nistagmo pós-calórico em pacientes com vestibulopatias periféricas crônicas.PURPOSE: to analyze the effect of air caloric stimulation at 10ºC on the post-caloric responses in patients with chronic peripheral dysfunction who presented spontaneous nystagmus with the eyes closed. METHODS: 61 patients with spontaneous nystagmus with closed eyes were submitted to air caloric stimulation under the following temperatures: 42, 18 and 10ºC. RESULTS: in 42 patients (69.8%, abnormal values of directional preponderance and / or unilateral hypoexcitability were observed following the 42ºC and 18ºC stimulations. For the 10ºC stimulations an asymmetry within normal limits was seen in 52.5% of the patients, while abnormal values were seen in 16.4% (p=0.012. Unilateral hypoexcitability was confirmed in 11.5% of the cases. In 8.2% of the patients there were abnormal findings not evidenced under 42ºC and 18ºC stimulations. CONCLUSION: in patients with chronic peripheral labyrinthine disorders who show spontaneous nystagmus with closed eyes, the 10ºC caloric test makes it possible to remove the influence of the spontaneous

  19. [Caloric restriction: about its positive metabolic effects and cellular impact].

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    Ortiz-Bautista, Raúl Julián; Aguilar-Salinas, Carlos Alberto; Monroy-Guzmán, Adriana

    2013-01-01

    Caloric restriction, as a 30 to 60% decrease of ad libitum balanced caloric intake, without malnutrition, is the non-genetic strategy that has consistently extended the average and maximum lifespan of most living beings, and it has been tested from unicellular organisms like yeast Saccharomyces cerevisiae to Rhesus primates. In addition, various genetic and pharmacological caloric restriction models have shown to protect against cancer, cardiovascular and neurodegenerative diseases. Primate studies suggest that this intervention delays the onset of age-related diseases; in humans, it has physiological, biochemical and metabolic effects decreasing diabetes and cardiovascular disease risk factor. Although currently the mechanism by which caloric restriction has its positive effects at the cellular level is unknown, it has been reported to decrease oxidative stress and increase in mitochondrial biogenesis.

  20. Elementi di trasmissione del calore

    CERN Document Server

    Guglielmini, Giovanni

    1990-01-01

    Introduzione ; concetti fondamentali di conduzione termica ; conduzione termica in regime stazionario ; conduzione termica in regime variabile ; analisi numerica nei problemi do conduzione ; concetti fondamentali di convezione termica ; convezione forzata ; convezione naturale ; scambio termico in ebollizione e condensazione ; concetti fondamentali di radiazione termica ; scambio termico per radiazione ; scambiatori di calore ; problemi termici negli edifici.

  1. Modeling microscale heat transfer using Calore.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Rader, Daniel John; Wong, Chung-Nin Channy; Bainbridge, Bruce L.; Torczynski, John Robert; Piekos, Edward Stanley

    2005-09-01

    Modeling microscale heat transfer with the computational-heat-transfer code Calore is discussed. Microscale heat transfer problems differ from their macroscopic counterparts in that conductive heat transfer in both solid and gaseous materials may have important noncontinuum effects. In a solid material, three noncontinuum effects are considered: ballistic transport of phonons across a thin film, scattering of phonons from surface roughness at a gas-solid interface, and scattering of phonons from grain boundaries within the solid material. These processes are modeled for polycrystalline silicon, and the thermal-conductivity values predicted by these models are compared to experimental data. In a gaseous material, two noncontinuum effects are considered: ballistic transport of gas molecules across a thin gap and accommodation of gas molecules to solid conditions when reflecting from a solid surface. These processes are modeled for arbitrary gases by allowing the gas and solid temperatures across a gas-solid interface to differ: a finite heat transfer coefficient (contact conductance) is imposed at the gas-solid interface so that the temperature difference is proportional to the normal heat flux. In this approach, the behavior of gas in the bulk is not changed from behavior observed under macroscopic conditions. These models are implemented in Calore as user subroutines. The user subroutines reside within Sandia's Source Forge server, where they undergo version control and regression testing and are available to analysts needing these capabilities. A Calore simulation is presented that exercises these models for a heated microbeam separated from an ambient-temperature substrate by a thin gas-filled gap. Failure to use the noncontinuum heat transfer models for the solid and the gas causes the maximum temperature of the microbeam to be significantly underpredicted.

  2. Isolated directional preponderance of caloric nystagmus: I. Clinical significance.

    Science.gov (United States)

    Halmagyi, G M; Cremer, P D; Anderson, J; Murofushi, T; Curthoys, I S

    2000-07-01

    To determine the clinical significance of an isolated directional preponderance (DP) on bithermal caloric testing. An isolated caloric DP was defined as a DP, calculated according to the standard Jongkees formula, of > or = 40%, with a spontaneous nystagmus (SN) in darkness of or = 40%. This was followed by a review of the clinical data on the 144 patients identified with such a result and then by a telephone or postal follow-up study of these patients. The study group eventually comprised 114 patients; these were patients in whom a clinical diagnosis could be made at the time the caloric test was done, or who responded to requests for follow-up information. The 34 patients in whom a clinical diagnosis could not be made at the time of the caloric test, and who did not respond to requests for follow-up information, were excluded. A balance disorders clinic in a tertiary referral hospital. All patients underwent standard bithermal caloric testing. Some of the patients also underwent rotational testing. A clinical diagnosis for the cause of the isolated DP, made either at the time of the caloric test or on the basis of information supplied at follow-up by the patient or by the referring physician. Of 114 patients, 39 had benign paroxysmal positioning vertigo, 14 had Ménière's disease, and 5 had migrainous vertigo. Five patients had central nervous system (CNS) disorders, and this was clinically apparent at the time of the caloric test in 4, so that only 1 patient with an isolated DP developed evidence of a CNS disorder after the caloric test was done. In the other 54 patients, no definite diagnosis could be made, but 41 of these 54 were either completely well or much better at follow-up. An isolated DP on caloric testing is usually a transient, benign disorder. About half the patients with an isolated DP have either Ménière's disease or benign paroxysmal positioning vertigo; in most of the other half, no definite diagnosis is made but most of these patients will

  3. Carnot to Clausius: Caloric to Entropy

    Science.gov (United States)

    Newburgh, Ronald

    2009-01-01

    This paper discusses how the Carnot engine led to the formulation of the second law of thermodynamics and entropy. The operation of the engine is analysed both in terms of heat as the caloric fluid and heat as a form of energy. A keystone of Carnot's thinking was the absolute conservation of caloric. Although the Carnot analysis was partly…

  4. Higher Unsaturation and Peroxidizability Indices in Caloric ...

    African Journals Online (AJOL)

    In this report, Drosophila melanogaster were maintained on caloric restricted and normal diets for varying periods, mitochondrial phospholipid fatty acids were extracted and analyzed. Whilst 10 days and 20 days of caloric restriction did not cause any significant change in mitochondrial phospholipid fatty acid composition, ...

  5. Postoral Glucose Sensing, Not Caloric Content, Determines Sugar Reward in C57BL/6J Mice

    Science.gov (United States)

    Zukerman, Steven; Ackroff, Karen

    2015-01-01

    Recent studies suggest that because of their energy value, sugars are more rewarding than non-caloric sweeteners. However, intragastric infusion data indicate that sugars differ in their postoral appetite-stimulating effects. We therefore compared the preference for isocaloric 8% sucrose, glucose, and fructose solutions with that of a non-caloric sweetener solution (0.8% sucralose) in C57BL/6J mice. Brief 2-bottle tests indicated that sucralose was isopreferred to sucrose but more preferred than glucose or fructose. Yet, in long-term tests, the mice preferred sucrose and glucose, but not fructose to sucralose. Additional experiments were conducted with a non-caloric 0.1% sucralose + 0.1% saccharin mixture (S + S), which does not have the postoral inhibitory effects of 0.8% sucralose. The S + S was preferred to fructose in brief and long-term choice tests. S + S was also preferred to glucose and sucrose in brief tests, but the sugars were preferred in long-term tests. In progressive ratio tests, non-deprived and food-deprived mice licked more for glucose but not fructose than for S + S. These findings demonstrate that the nutrient-specific postoral actions, not calories per se, determine the avidity for sugar versus non-caloric sweeteners. Furthermore, sweet taste intensity and potential postoral inhibitory actions must be considered in comparing non-caloric and caloric sweeteners. PMID:25715333

  6. Caloric beverage consumption patterns in Mexican children

    Directory of Open Access Journals (Sweden)

    Rivera Juan A

    2010-10-01

    Full Text Available Abstract Background Mexico has seen a very steep increase in child obesity level. Little is known about caloric beverage intake in this country as well as all other countries outside a few high income countries. This study examines overall patterns and trends in all caloric beverages from two nationally representative surveys from Mexico. Methods The two nationally representative dietary intake surveys (1999 and 2006 from Mexico are used to study caloric beverage intake in 17, 215 children. The volume (ml and caloric energy (kcal contributed by all beverages consumed by the sample subjects were measured. Results are weighted to be nationally representative. Results The trends from the dietary intake surveys showed very large increases in caloric beverages among pre-school and school children. The contribution of whole milk and sugar-sweetened juices was an important finding. Mexican pre-school children consumed 27.8% of their energy from caloric beverages in 2006 and school children consumed 20.7% of their energy from caloric beverages during the same time. The three major categories of beverage intake are whole milk, fruit juice with various sugar and water combinations and carbonated and noncarbonated sugared-beverages. Conclusion The Mexican government, greatly concerned about obesity, has identified the large increase in caloric beverages from whole milk, juices and soft drinks as a key target and is initiating major changes to address this problem. They have already used the data to shift 20 million persons in their welfare and feeding programs from whole to 1.5% fat milk and in a year will shift to nonfat milk. They are using these data to revise school beverage policies and national regulations and taxation policies related to an array of less healthful caloric beverages.

  7. Is contextual-potentiated eating dependent on caloric density of food?

    Directory of Open Access Journals (Sweden)

    Fernando Fernández-Aranda

    2009-01-01

    Full Text Available One experiment tested whether a specific context could elicit eating in rats as a result of Pavlovian conditioning and whether this effect depended on the caloric density of food. Thirty two deprived rats experienced two contexts. They had access to food in context A, but no food was available in context B. During conditioning, half of the animals received high density caloric food (HD groups whereas the other half, low density caloric food (LD groups. Then, half of the rats in each type of food group was tested in context A and the other half in context B. The results demonstrated an effect of context conditioning only in HD groups. These findings suggest the relevance of both contextual conditioning and caloric density of food in eating behaviour. Implications for the aetiology of binge eating will be discussed.

  8. Oxytocin reduces caloric intake in men

    National Research Council Canada - National Science Library

    Lawson, Elizabeth A; Marengi, Dean A; DeSanti, Rebecca L; Holmes, Tara M; Schoenfeld, David A; Tolley, Christiane J

    2015-01-01

    .... Oxytocin effects on nutrition and metabolism in humans are not well defined. It was hypothesized that oxytocin would reduce caloric intake and appetite and alter levels of appetite-regulating hormones...

  9. Epigenetic regulation of caloric restriction in aging

    National Research Council Canada - National Science Library

    Li, Yuanyuan; Daniel, Michael; Tollefsbol, Trygve O

    2011-01-01

    .... The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models...

  10. Fasting or caloric restriction for healthy aging.

    Science.gov (United States)

    Anton, Stephen; Leeuwenburgh, Christiaan

    2013-10-01

    Aging is associated with a host of biological changes that contribute to a progressive decline in cognitive and physical function, ultimately leading to a loss of independence, and increased risk of mortality. To date, prolonged caloric restriction (i.e., a reduction in caloric intake without malnutrition) is the only non-genetic intervention that has consistently been found to extend both mean and maximal life span across a variety of species. Most individuals have difficulty sustaining prolonged caloric restriction, which has led to a search for alternative approaches that can produce similar to benefits as caloric restriction. A growing body of evidence indicates that fasting periods and intermittent fasting regimens in particular can trigger similar biological pathways as caloric restriction. For this reason, there is increasing scientific interest in further exploring the biological and metabolic effects of intermittent fasting periods, as well as whether long-term compliance may be improved by this type of dietary approach. This special will highlight the latest scientific findings related to the effects of both caloric restriction and intermittent fasting across various species including yeast, fruit flies, worms, rodents, primates, and humans. A specific emphasis is placed on translational research with findings from basic bench to bedside reviewed and practical clinical implications discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Strenuous exercise with caloric restriction: effect on luteinizing hormone secretion.

    Science.gov (United States)

    Williams, N I; Young, J C; McArthur, J W; Bullen, B; Skrinar, G S; Turnbull, B

    1995-10-01

    To test whether strenuous exercise with and without caloric restriction alters LH secretion, and whether these changes are apparent in the immediate post-exercise period, LH pulse parameters were studied in four moderately trained eumenorrheic women over three successive menstrual cycles. Blood samples were obtained 5 h before and 5 h after 90 min of running at 74% VO2max. Each test was preceded by a 7-d treatment of controlled diet and exercise (74% VO2max). During CONTROL, subjects were eucaloric on days 1-7, and performed no exercise on days 5-7. During STTI (short-term training increase), subjects were eucaloric and completed 90 min runs on days 5-7. During DIET/STTI, subjects consumed 60% of the calories necessary to maintain weight on days 1-7, and exercised as in STTI. A significant decrease in overall (0700-1830 h) LH pulse frequency during DIET/STTI compared with CONTROL and STTI treatments was observed. No changes were found in mean serum LH levels or peak amplitude. These results suggest that high-volume training combined with caloric restriction may predispose one to exercise-induced changes in LH pulse frequency, while adequate caloric intake may prevent these changes.

  12. Oxytocin reduces caloric intake in men.

    Science.gov (United States)

    Lawson, Elizabeth A; Marengi, Dean A; DeSanti, Rebecca L; Holmes, Tara M; Schoenfeld, David A; Tolley, Christiane J

    2015-05-01

    Preclinical studies indicate that oxytocin is anorexigenic and has beneficial metabolic effects. Oxytocin effects on nutrition and metabolism in humans are not well defined. It was hypothesized that oxytocin would reduce caloric intake and appetite and alter levels of appetite-regulating hormones. Metabolic effects of oxytocin were also explored. A randomized, placebo-controlled crossover study of single-dose intranasal oxytocin (24 IU) in 25 fasting healthy men was performed. After oxytocin/placebo, subjects selected breakfast from a menu and were given double portions. Caloric content of food consumed was measured. Visual analog scales were used to assess appetite, and blood was drawn for appetite-regulating hormones, insulin, and glucose before and after oxytocin/placebo. Indirect calorimetry assessed resting energy expenditure (REE) and substrate utilization. Oxytocin reduced caloric intake with a preferential effect on fat intake and increased levels of the anorexigenic hormone cholecystokinin without affecting appetite or other appetite-regulating hormones. There was no effect of oxytocin on REE. Oxytocin resulted in a shift from carbohydrate to fat utilization and improved insulin sensitivity. Intranasal oxytocin reduces caloric intake and has beneficial metabolic effects in men without concerning side effects. The efficacy and safety of sustained oxytocin administration in the treatment of obesity warrants investigation. © 2014 The Obesity Society.

  13. Higher Unsaturation and Peroxidizability Indices in Caloric ...

    African Journals Online (AJOL)

    The biochemical processes involved in ageing are poorly understood. One of the general approaches to understanding the mechanism of ageing is to study the effect of experimental manipulations on life-span and the properties that are affected by them. Some of these experimental manipulations are caloric restriction and ...

  14. Epigenetic regulation of caloric restriction in aging

    Directory of Open Access Journals (Sweden)

    Daniel Michael

    2011-08-01

    Full Text Available Abstract The molecular mechanisms of aging are the subject of much research and have facilitated potential interventions to delay aging and aging-related degenerative diseases in humans. The aging process is frequently affected by environmental factors, and caloric restriction is by far the most effective and established environmental manipulation for extending lifespan in various animal models. However, the precise mechanisms by which caloric restriction affects lifespan are still not clear. Epigenetic mechanisms have recently been recognized as major contributors to nutrition-related longevity and aging control. Two primary epigenetic codes, DNA methylation and histone modification, are believed to dynamically influence chromatin structure, resulting in expression changes of relevant genes. In this review, we assess the current advances in epigenetic regulation in response to caloric restriction and how this affects cellular senescence, aging and potential extension of a healthy lifespan in humans. Enhanced understanding of the important role of epigenetics in the control of the aging process through caloric restriction may lead to clinical advances in the prevention and therapy of human aging-associated diseases.

  15. Postoral glucose sensing, not caloric content, determines sugar reward in C57BL/6J mice.

    Science.gov (United States)

    Sclafani, Anthony; Zukerman, Steven; Ackroff, Karen

    2015-05-01

    Recent studies suggest that because of their energy value, sugars are more rewarding than non-caloric sweeteners. However, intragastric infusion data indicate that sugars differ in their postoral appetite-stimulating effects. We therefore compared the preference for isocaloric 8% sucrose, glucose, and fructose solutions with that of a non-caloric sweetener solution (0.8% sucralose) in C57BL/6J mice. Brief 2-bottle tests indicated that sucralose was isopreferred to sucrose but more preferred than glucose or fructose. Yet, in long-term tests, the mice preferred sucrose and glucose, but not fructose to sucralose. Additional experiments were conducted with a non-caloric 0.1% sucralose + 0.1% saccharin mixture (S + S), which does not have the postoral inhibitory effects of 0.8% sucralose. The S + S was preferred to fructose in brief and long-term choice tests. S + S was also preferred to glucose and sucrose in brief tests, but the sugars were preferred in long-term tests. In progressive ratio tests, non-deprived and food-deprived mice licked more for glucose but not fructose than for S + S. These findings demonstrate that the nutrient-specific postoral actions, not calories per se, determine the avidity for sugar versus non-caloric sweeteners. Furthermore, sweet taste intensity and potential postoral inhibitory actions must be considered in comparing non-caloric and caloric sweeteners. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Caloric Requirements of Patients With Brain Impairment and Cerebral Palsy Who Are Dependent on Chronic Ventilation.

    Science.gov (United States)

    Gale, Rena; Namestnic, Julia; Singer, Pierre; Kagan, Ilya

    2017-11-01

    Israeli law mandates chronic ventilator support for children and adolescents who are severely brain impaired and show minimal responses. Feeding protocols in these cases have been based on the caloric requirements of healthy children, deducting calories for lack of activity as well as an individual adjustment according to the cerebral palsy growth curves. However, patients are still inclined to gain excessive weight. Our objective was to determine the caloric requirements of these patients. Sixteen patients hospitalized in a dedicated unit who were ventilated through tracheostomies and fed via gastrostomies were included. Patients were aged 3-24 years; duration of ventilation was 1-7.5 years; and diagnoses included congenital genetic or brain malformations (n = 9), hypoxic accidents (n = 4), and postbacterial or postviral encephalitis (n = 3). Resting energy expenditure (REE) was determined by indirect calorimetry. REE values were compared with the caloric requirements of age-comparable healthy children and the calories actually delivered. Data were analyzed with paired t tests, Pearson correlations, and linear regression. The REE of our patients was 46% lower than the estimated caloric requirements of healthy children. In practice, patients received 32% more calories than that measured by REE. These findings were not affected by age, weight, diagnosis, or length of hospitalization. The caloric expenditure of these patients is very low. A diet guided by indirect calorimetry is proposed to aid in providing optimal nutrition support for this unique population to avoid overfeeding and obesity.

  17. Intake of calorically sweetened beverages and obesity

    DEFF Research Database (Denmark)

    Olsen, N J; Heitmann, B L

    2009-01-01

    The prevalence of obesity has increased in the past 30 years, and at the same time a steep increase in consumption of soft drinks has been seen. This paper reviews the literature for studies on associations between intake of calorically sweetened beverages and obesity, relative to adjustment...... for energy intake. Conclusions from previous reviews have been inconsistent, but some included many cross-sectional studies or studies supported by sugar industry. A literature search was performed for prospective and experimental studies using Medline and Scirus. Fourteen prospective and five experimental...... not find effects. Eight prospective studies adjusted for energy intake. Seven of these studies reported associations that were essentially similar before and after energy adjustment. In conclusion, a high intake of calorically sweetened beverages can be regarded as a determinant for obesity. However...

  18. Transferencia de calor a lechos empacados

    OpenAIRE

    Beltrán Feged, Alvaro; Bonilla Melendez, Alberto; Cancelado Arias, Miguel

    2012-01-01

    Consideremos el lecho de solidos granulados de la figura 1.El lecho esta a una temperatura u (z,t), y tiene un calor especifico  cs, que se toma constante. z es la altura del lecho, y t es el tiempo. A este lecho entran G unidades de masa de fluido por unidad de tiempo y de área de sección de lecho(1)(2)

  19. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Science.gov (United States)

    Xu, Xiao-Meng; Cai, Guang-Yan; Bu, Ru; Wang, Wen-Juan; Bai, Xue-Yuan; Sun, Xue-Feng; Chen, Xiang-Mei

    2015-01-01

    Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published. All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI), OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang). The pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by using fixed- or random-effects models. The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR) group was significantly lower than that in the ad libitum-fed (AL) group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL) group. Our findings demonstrate for the

  20. Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

    Directory of Open Access Journals (Sweden)

    Xiao-Meng Xu

    Full Text Available Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published.All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI, OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang. The pooled odds ratios (OR and 95% confidence intervals (95% CI were calculated by using fixed- or random-effects models.The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR group was significantly lower than that in the ad libitum-fed (AL group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL group.Our findings

  1. Use of non-caloric edulcorants in children

    OpenAIRE

    Calzada León Raúl; Altamirano Bustamante Nelly

    2014-01-01

    We analyze the health normativity for the denomination of non caloric edulcorants in Mexico, and the authorization for the use of natural and synthetic non caloric edulcorants in newborn and until puberty. Special emphasis was given to the consecutive points of safety required in order to assure that they are free of secondary effects. For each non caloric edulcorant available in Mexico, we looked into the studies which mention their side effects in terms of growth and overall.

  2. Use of non-caloric edulcorants in children

    Directory of Open Access Journals (Sweden)

    Calzada León Raúl

    2014-07-01

    Full Text Available We analyze the health normativity for the denomination of non caloric edulcorants in Mexico, and the authorization for the use of natural and synthetic non caloric edulcorants in newborn and until puberty. Special emphasis was given to the consecutive points of safety required in order to assure that they are free of secondary effects. For each non caloric edulcorant available in Mexico, we looked into the studies which mention their side effects in terms of growth and overall.

  3. [Comparison of caloric responses between vestibular migraine and Ménière disease patients].

    Science.gov (United States)

    Yang, Yuechang; Zhuang, Jianhua; Zhou, Lili; Tong, Bei; Zhou, Xiaowen; Gao, Bo

    2016-01-01

    To compare the features of caloric tests in vestibular migraine (VM) and Menière's disease (MD) patients, and provide objective evidence for differentiating the 2 groups of patients. This case-control study included 11 MD patients with left ear involved and mild to moderate impaired hearing, and 18 matched cases with VM. All participants received caloric tests. Maximum slow phase velocities (SPVmax) were used to describe horizontal and vertical nystagmus respectively and were compared between the 2 groups. Horizontal and vertical canal parasis(CP) were calculated according to respective SPVmax. Unilateral (UW-VR) or bilateral (BW-VR) weakness of vestibular response, and positive unilateral (UVR) or bilateral (BVR) vertical response or negative bilateral vertical response (NBVR) were judged by the boundary point of SPVmax of 5°/s respectively. Total left (LV) or right (RV) Vertical reactions were calculated accoeding to vertical SPVmax,and inter ears difference of vertical responses (IED-VR) calculated from LV minus RV. There were no significant differences in age and gender between the 2 groups. Horizontal SPVmax of all of caloric tests of VM group,except the left cold (LC), were statistically larger than that of MD group (P VR and BW-VR in VM group (5.56%, 0) were significantly lower than that in MD group (27.27%, 18.18%) (P VR in VM group (left intenser: 16.67%, right intenser: 83.33%) was statistically different from that in MD group (left intenser: 36.36%, right intenser: 9.09%, both no difference: 54.55%) (P Vestibular responses of caloric test are more sensitive, and vertical reactions are more easily induced in VM patients than in MD. Caloric test can be used to differentiate the 2 groups of diseases.

  4. A Dissociation between Recognition and Hedonic Value in Caloric and Non-caloric Carbonated Soft Drinks

    Directory of Open Access Journals (Sweden)

    Franco eDelogu

    2016-01-01

    Full Text Available Consumption of sugar-sweetened beverages (SSBs is considered to be a contributor to diabetes and the epidemic of obesity in many countries. The popularity of non-caloric carbonated soft drinks as an alternative to SSBs may be a factor in reducing the health risks associated with SSBs consumption. This study focuses on the perceptual discrimination of SSBs from artificially sweetened beverages (ASBs. 55 college students rated 14 commercially available carbonated soft drinks in terms of sweetness and likeability. They were also asked to recognize if the drinks contained sugar or a non-caloric artificial sweetener. Overall, participants showed poor accuracy in discriminating drinks’ sweeteners, with significantly lower accuracy for SSBs than ASBs. Interestingly, we found a dissociation between sweetener recognition and drink pleasantness. In fact, in spite of a chance-level discrimination accuracy of SSBs, their taste was systematically preferred to the taste of non-caloric beverages. Our findings support the idea that hedonic value of carbonated soft drinks is dissociable from its identification and that the activation of the pleasure system seems not to require explicit recognition of the sweetener contained in the soft drink. We hypothesize that preference for carbonated soft drinks containing sugar over non-caloric alternatives might be modulated by metabolic factors that are independent from conscious and rational consumers’ choices.

  5. Caloric versus low-caloric sweeteners: Can the body be fooled?

    NARCIS (Netherlands)

    Smeets, P.A.M.

    2010-01-01

    Low-caloric artificial sweeteners have been around for several decades now. Still, the debate over their usefulness in decreasing energy intake is ongoing. In principle, replacing sugar-containing foods with 'light' versions will lead to decreased energy intake. However, the reality of food intake

  6. Nutrigenetics and nutrigenomics of caloric restriction.

    Science.gov (United States)

    Abete, Itziar; Navas-Carretero, Santiago; Marti, Amelia; Martinez, J Alfredo

    2012-01-01

    Obesity is a complex disease resulting from a chronic and long-term positive energy balance in which both genetic and environmental factors are involved. Weight-reduction methods are mainly focused on dietary changes and increased physical activity. However, responses to nutritional intervention programs show a wide range of interindividual variation, which is importantly influenced by genetic determinants. In this sense, subjects carrying several obesity-related single-nucleotide polymorphisms (SNPs) show differences in the response to calorie-restriction programs. Furthermore, there is evidence indicating that dietary components not only fuel the body but also participate in the modulation of gene expression. Thus, the expression pattern and nutritional regulation of several obesity-related genes have been studied, as well as those that are differentially expressed by caloric restriction. The responses to caloric restriction linked to the presence of SNPs in obesity-related genes are reviewed in this chapter. Also, the influence of energy restriction on gene expression pattern in different tissues is addressed. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. The reno-protective effects of dietary caloric restriction against ...

    African Journals Online (AJOL)

    This study has demonstrated that these pathophysiological alterations caused by disturbed glucose homeostasis are reversed by caloric restriction and thus CR may have therapeutic/preventive potential towards the development of diabetic nephropathy. Keywords: dietary caloric restriction; lipid peroxidation; oxidative ...

  8. Combined Salt and Caloric Restrictions: Potential Adverse Outcomes.

    Science.gov (United States)

    Homma, Tsuyoshi; Homma, Mika; Huang, Yuefei; Mayurasakorn, Korapat; Rodi, Nurul Mahamad; Hamid, Anis Amalina Abdul; Hurwitz, Shelley; Yao, Tham; Adler, Gail K; Pojoga, Luminita H; Williams, Gordon H; Romero, Jose R

    2017-10-11

    We hypothesized that caloric restriction (CR) and salt restriction (ResS) would have similar effects on reducing cardiovascular risk markers and that combining CR and ResS would be synergistic in modulating these markers. To test our hypothesis, rats were randomized into 2 groups: ad libitum liberal salt diet (ad libitum/high-sodium, 1.6% sodium) or ResS diet (ad libitum/ResS, 0.03% sodium). CR was initiated in half of the rats in each group by reducing caloric intake to 60% while maintaining sodium intake constant (CR/high-sodium, 2.7% sodium or CR/ResS, 0.05% sodium) for 4 weeks. CR in rats on a high-sodium diet improved metabolic parameters, renal transforming growth factor-β and collagen-1α1 and increased plasma adiponectin and renal visfatin and NAD+ protein levels. Although CR produced some beneficial cardiovascular effects (increased sodium excretion and reduced blood pressure), it also was associated with potentially adverse cardiovascular effects. Adrenal zona glomerulosa cell responsiveness and aldosterone levels and activation were inappropriately increased for the volume state of the rodent. Like CR on HS, CR on a ResS diet also produced relative increased zona glomerulosa responsiveness and an increased blood pressure with no improvement in metabolic parameters. These results suggest that combining CR and ResS may decrease the beneficial effects of each alone. Furthermore, CR, regardless of dietary salt intake, inappropriately activates aldosterone production. Thus, caution should be used in combining ResS and CR because the combination may lead to increased cardiovascular risk. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  9. Focos de Calor na Mata Atlântica do Estado do Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Sara dos Santos Clemente

    Full Text Available Resumo O estudo avaliou a ocorrência de focos de calor nos remanescentes da Mata Atlântica no estado do Rio de Janeiro, sob o aspecto climático. As informações obtidas da base de dados BDQueimadas, do período de junho de 1998 a dezembro de 2015, sofreram estatística descritiva, exploratória e paramétrica. As maiores ocorrências de focos de calor foram registradas nos meses de agosto, setembro e outubro e, os anos com os maiores registros foram nos ciclos 2010/2011 (16,06% e 2014/2015 (41, 24%, ambos somaram 57,30% da série temporal, referente a La Niña e El Niño nas categorias forte e fraco. O teste paramétrico mostrou uma repetição dos meses de abril e junho nos anos avaliados na série temporal de focos de calor. As regiões de Governo Centro-Sul Fluminense e Médio Paraíba registraram os maiores registros de focos de calor, segundo a avaliação espacial. Nossos resultados demonstram que o acesso a uma base gratuita de dados permite a prevenção de danos causados pelas queimadas e incêndios. Com a evolução dos sensores de temperatura e de algoritmos de tratamento de dados, será possível diferenciar os focos de calor que representam incêndios e queimadas daqueles que indicam, por exemplo, atividade de indústrias.

  10. Caloric compensation in preschool children: Relationships with body mass and differences by food category.

    Science.gov (United States)

    Carnell, S; Benson, L; Gibson, E L; Mais, L A; Warkentin, S

    2017-09-01

    Maintaining a healthy weight may involve compensating for previously consumed calories at subsequent meals. To test whether heavier children demonstrated poorer caloric compensation across a range of conditions, and to explore whether compensation failure was the result of inadequate adjustment of overall intake or specific over-consumption of highly palatable, high energy-density 'junk' foods, we administered two compensation tests to a sample of 4-5 y olds. For Test A, preloads varied only in carbohydrate content and were organoleptically indistinguishable (200 ml orange-flavored beverage [0 kcal vs. 200 kcal]). For Test B, the preloads varied substantially in both macronutrient composition and learned gustatory cues to caloric content (200 ml water [0 kcal] vs. 200 ml strawberry milkshake [200 kcal]). Each preload was followed 30 min later by a multi-item ad-libitum meal containing junk foods (chocolate cookies, cheese-flavored crackers) and core foods (fruits and vegetables, bread rolls, protein foods). Testing took place at the children's own school under normal lunch-time conditions. Children were weighed and measured. Caloric compensation occurred in both tests, in terms of total, junk and core food intake (RMANOVA, all p junk food intake (RMANOVA preload-by-weight group interaction p effect for core foods. Our results suggest that caloric compensation is consistently poorer in heavier children, and that overweight/obese children's preferences for junk foods may overwhelm intake regulation mechanisms within meals containing those foods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Peripheral ghrelin enhances sweet taste food consumption and preference, regardless of its caloric content.

    Science.gov (United States)

    Disse, Emmanuel; Bussier, Anne-Lise; Veyrat-Durebex, Christelle; Deblon, Nicolas; Pfluger, Paul T; Tschöp, Matthias H; Laville, Martine; Rohner-Jeanrenaud, Françoise

    2010-09-01

    Ghrelin is one of the most potent orexigens known to date. While the prevailing view is that ghrelin participates in the homeostatic control of feeding, the question arose as to whether consummatory responses evoked by this compound could be related to search for reward. We therefore attempted to delineate the involvement of ghrelin in the modulation of non-caloric but highly rewarding consumption. We tested the effect of intraperitoneally injected ghrelin on the acceptance and preference for a 0.3% saccharin solution using single bottle tests and free-choice preference test procedures in C57BL6/J mice, as well as in mice lacking the ghrelin receptor (GHSR1a -/-) and their wild-type (WT) littermates. In the single bottle tests, peripheral ghrelin consistently increased the consumption of saccharin, independently of availability of caloric food. In the free-choice preference test procedures, ghrelin increased the preference for saccharin in WT mice, while it did had not effect in GHSR1a -/-animals, indicating that the ghrelin receptor pathway is necessary to mediate this parameter. Peripheral ghrelin enhances intake and preference for a sweet food, regardless of whether the food has caloric content. This effect, mediated through the ghrelin receptor pathway, may serve as additional enhancers of energy intake. Copyright 2010 Elsevier Inc. All rights reserved.

  12. Caloric Value of Some Forest Fuels of the Southern United States

    Science.gov (United States)

    Walter A. Hough

    1969-01-01

    The caloric value of a variety of southern forest fuels was determined in an oxygen bomb calorimeter. High heat values ranged between about 3,600 and 5,200 cal./g. for fuels as sampled and between 4,500 and 5,600 cal./g. for fuels on an ash-free basis. Additional tests of forest fuels from the Southern, Eastern, and North Central United States showed a...

  13. Characteristics of non caloric dulcorants and their use in children

    OpenAIRE

    Calzada León Raúl; Altamirano Bustamante Nelly

    2014-01-01

    This is a descriptive review of the elaboration routes, the physical and chemical characteristics, metabolism and clearance, sweetener level, residual flavor, maximal recommended ingestion, security levels and the assessment of growth and development problems in children (from newborns, including prematures, to the end of puberty), of the main no caloric edulcorants used in Mexico. The no caloric edulcorants included in this review are: aspartame, acesulfame-K, sucralose, sacarin, ciclamates,...

  14. Characteristics of non caloric dulcorants and their use in children

    Directory of Open Access Journals (Sweden)

    Calzada León Raúl

    2014-07-01

    Full Text Available This is a descriptive review of the elaboration routes, the physical and chemical characteristics, metabolism and clearance, sweetener level, residual flavor, maximal recommended ingestion, security levels and the assessment of growth and development problems in children (from newborns, including prematures, to the end of puberty, of the main no caloric edulcorants used in Mexico. The no caloric edulcorants included in this review are: aspartame, acesulfame-K, sucralose, sacarin, ciclamates, thaumatin, D- tagatose, estevia and alitame.

  15. Inferior vestibular neuritis: 3 cases with clinical features of acute vestibular neuritis, normal calorics but indications of saccular failure

    Directory of Open Access Journals (Sweden)

    Økstad Siri

    2006-12-01

    Full Text Available Abstract Background Vestibular neuritis (VN is commonly diagnosed by demonstration of unilateral vestibular failure, as unilateral loss of caloric response. As this test reflects the function of the superior part of the vestibular nerve only, cases of pure inferior nerve neuritis will be lost. Case presentations We describe three patients with symptoms suggestive of VN, but normal calorics. All 3 had unilateral loss of vestibular evoked myogenic potential. A slight, asymptomatic position dependent nystagmus, with the pathological ear down, was observed. Conclusion We believe that these patients suffer from pure inferior nerve vestibular neuritis.

  16. Role of caloric homeostasis and reward in alcohol intake in Syrian golden hamsters

    OpenAIRE

    Gulick, Danielle; Green, Alan I.

    2010-01-01

    The Syrian golden hamster drinks alcohol readily, but only achieves moderate blood alcohol levels, and does not go through withdrawal from alcohol. Because the hamster is a model of caloric homeostasis, both caloric content and reward value may contribute to the hamster’s alcohol consumption. The current study examines alcohol consumption in the hamster when a caloric or non-caloric sweet solution is concurrently available and caloric intake in the hamster before, during, and after exposure t...

  17. Use of caloric and non-caloric sweeteners in US consumer packaged foods, 2005–9

    Science.gov (United States)

    Ng, Shu Wen; Slining, Meghan M.; Popkin, Barry M.

    2012-01-01

    Our understanding of the use of caloric (CS) and non-caloric sweeteners (NCS) in the US food supply is limited. This study utilizes full ingredient list and nutrition facts panel (NFP) data from Gladson Nutrition Database, and nationally representative purchases of consumer packaged foods from Nielsen Homescan in 2005 through 2009 to understand the use of CS (including FJC) and NCS in CPG foods. Of the 85,451 uniquely formulated foods purchased during 2005–2009, 75% contain sweeteners (68% with CS only, 1% with NCS only, 6% with both CS and NCS). CS are in >95% of cakes/cookies/pies, granola/protein/energy bars, ready-to-eat cereals, sweet snacks, and sugar-sweetened beverages. NCS are in >33% of yogurts and sports/energy drinks, 42% of waters (plain or flavored), and most diet sweetened beverages. Across unique products, corn syrup is the most commonly listed sweetener, followed by sorghum, cane sugar, high fructose corn syrup and FJC. Also, 77% of all calories purchased in the US in 2005–2009 contained CS and 3% contained NCS, while 73% of the volume of foods purchased contained CS and 15% contained NCS. Trends during this period suggest a shift towards the purchase of NCS-containing products.Our study poses a challenge toward monitoring sweetener consumption in the US by discussing the need and options available to improve measures of CS and NCS, and additional requirements on NFPs on CPG foods. PMID:23102182

  18. Normal physical activity obliterates the deleterious effects of a high-caloric intake.

    Science.gov (United States)

    Krogh-Madsen, Rikke; Pedersen, Maria; Solomon, Thomas P J; Knudsen, Sine Haugaard; Hansen, Louise Seier; Karstoft, Kristian; Lehrskov-Schmidt, Louise; Pedersen, Karin Kaereby; Thomsen, Carsten; Holst, Jens Juul; Pedersen, Bente K

    2014-02-01

    A high-caloric intake combined with a sedentary lifestyle is an important player in the development of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine if the level of physical activity has impact on the metabolic effects of a high-caloric (+2,000 kcal/day) intake. Therefore, healthy individuals on a high-caloric intake were randomized to either 10,000 or 1,500 steps/day for 14 days. Step number, total energy expenditure, dietary records, neuropsychological tests, maximal oxygen uptake (Vo2max), whole body dual-energy X-ray absorptiometry (DXA) and abdominal magnetic resonance imaging (MRI) scans, continuous glucose monitoring (CGM), and oral glucose tolerance tests (OGTT) with stable isotopes were performed before and after the intervention. Both study groups gained the same amount of body weight. However, the inactive group accumulated significantly more visceral fat compared with the active group. Following the 2-wk period, the inactive group also experienced a poorer glycemic control, increased endogenous glucose production, decreased hepatic insulin extraction, increased baseline plasma levels of total cholesterol and LDL, and a decreased cognitive function with regard to capacity of attention. In conclusion, we find evidence to support that habitual physical activity may prevent pathophysiological symptoms associated with diet-induced obesity.

  19. Absorption heat pump integrated in an effluent purification system; Bomba de calor por absorcion integrada a un sistema de purificacion de efluentes

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo, Socrates; Siqueiros, Javier; Heard, Christopher; Santoyo, Edgar [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    The results derived of the integration of an absorption heat pump to an industrial effluents purification system, are presented. The advantages of these heat pumps with respect to heat pumps by mechanical compression of vapor, as well as the advantages in using absorption heat pumps in simple distillation systems, are mentioned. Finally, a description is made of the equipment designed and built, as well as the results obtained in a preliminary test. [Espanol] Se presentan los resultados derivados de la integracion de una bomba de calor por absorcion a un sistema de purificacion de efluentes industriales. Se mencionan las ventajas de este tipo de bombas de calor con respecto a las de calor por compresion mecanica de vapor, asi como las ventajas de usar bombas de calor en sistemas de destilacion simple. Finalmente, se describe el equipo disenado y construido, asi como los resultados obtenidos de una prueba preliminar.

  20. Research on heat pumps in Mexico operating with geothermal energy and waste heat; Investigacion sobre bombas de calor en Mexico operando con energia geotermica y calor de desecho

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, A; Barragan-Reyes, R.M; Arellano-Gomez, V [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx

    2008-01-15

    The Instituto de Investigaciones Electricas and the Comision Federal de Electricidad have done research and development (R&D) on heat pumps (HP) in past years. Tested systems include mechanical compression, absorption and heat-transformers. The main R&D aspects on HP are briefly described, and also a more detailed description about three of the main studies is presented: (a) a mechanical compression HP of the water-water type operated with low-pressure geothermal steam at the Los Azufres; Mich., geothermal field, and designed for purification of brine; (b) an absorption HP for cooling and refrigeration operating with ammonia-water and low-enthalpy geothermal energy, which was tested in the Los Azufres and Cerro Prieto, BC, geothermal fields; and (c) a heat-transformer by absorption-Absorption Heat Pump Type II-tested to assess the performance of several ternary solutions as work fluids. Plans exist to install and test a geothermal heat pump at Cerro Prieto or Mexicali, BC. [Spanish] El Instituto de Investigaciones Electricas y la Comision Federal de Electricidad han realizado trabajo de investigacion y desarrollo (I&D) sobre bombas de calor (BC) en el pasado. Los sistemas probados incluyen compresion mecanica, absorcion y transformadores termicos. Este trabajo describe brevemente los principales aspectos de I&D sobre bombas de calor en forma general, y se da una descripcion mas detallada de tres de los principales estudios: (a) una BC por compresion mecanica tipo agua-agua disenada para purificacion de salmueras operando con vapor geotermico de baja presion en el campo geotermico de Los Azufres, Mich.; (b) una BC por absorcion para enfriamiento y refrigeracion operando con amoniaco-agua y energia geotermica de baja entalpia, la cual fue probada en los campos geotermicos de Los Azufres y Cerro Prieto, BC; y (c) un transformador termico por absorcion -llamado Bomba de Calor por Absorcion Tipo II--, el cual fue probado para evaluar el comportamiento de diversas

  1. General and persistent effects of high-intensity sweeteners on body weight gain and caloric compensation in rats

    Science.gov (United States)

    Swithers, Susan E.; Baker, Chelsea R.; Davidson, T.L.

    2009-01-01

    In four experiments, we assessed the generality of previous findings (Swithers & Davidson, 2008) that increased caloric intake, body weight gain, and reduced caloric compensation are exhibited by rats that consume a diet containing a nonnutritive, high intensity sweetener. In this earlier work, rats consumed a diet in which saccharin was mixed in low-fat yogurt, and animals were provided with a fixed amount of the yogurt. The present experiments showed that the effects of saccharin on energy intake and body weight gain are also obtained when rats were given Acesulfame Potassium (AceK), a nonnutritive high intensity sweetener that is chemically distinct from saccharin. Increased energy intake and body weight gain and impaired caloric compensation were also obtained with a saccharin-sweetened base diet (refried beans) that was calorically similar, but nutritionally distinct from low-fat yogurt. The present studies also extended earlier findings by showing that body weight differences persist after saccharin-sweetened diets are discontinued and following a shift to a diet sweetened with glucose. In addition, rats first exposed to a diet sweetened with glucose still gain additional weight when subsequently exposed to a saccharin sweetened diet. The effect of saccharin on caloric compensation was more complex in that it appeared to depend on the type of diet (yogurt or beans) in which saccharin was consumed prior to testing. The results of these experiments add support to the hypothesis that exposure to weak or non-predictive relationships between sweet tastes and caloric consequences may lead to positive energy balance. PMID:19634935

  2. Heat pump for purification of geothermal brines; Bomba de calor para purificacion de salmuera geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Santoyo-Gutierrez, S; Barragan-Reyes, R.M; Holland, F.A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx

    2007-01-15

    Integrated use of geothermal resources is one of the most important goals for the future. Presently geothermal heat pumps offer two benefits: using heat from residual brines and converting these brines into very pure water. Designs and descriptions are presented of an experimental system to purify geothermal brines integrated to an adsorption heat-pump. The system was constructed and tested in the IIE (Institute for Electrical Research) facilities. During the experimental stage, pure water was obtained. Maximum capacity for pure water was 4.3 kg per hour, presenting an Actual Coefficient of Performance (COP)A of 1.4. The results are encouraging to project units at an industrial level for operating with geothermal and/or solar heat. [Spanish] El aprovechamiento integral de los recursos geotermicos en todas sus formas es una de las metas importantes a lograr en los proximos anos. Hoy en dia, el uso de las bombas de calor en la geotermia ofrece un doble beneficio: aprovechan el calor de los fluidos de desecho y tienen la capacidad de transformar la salmuera geotermica en agua de alta pureza. Se presenta el diseno y descripcion de un sistema experimental para purificacion de salmuera geotermica integrado a una bomba de calor por absorcion, el cual fue construido y probado en el Instituto de Investigaciones Electricas. En toda la etapa de experimentacion se obtuvo agua pura. La capacidad maxima alcanzada de produccion de agua pura de este sistema fue de 4.3 kg por hora, mostrando un rendimiento en terminos del Coeficiente Real de Rendimiento (COP)A de 1.4. Estos resultados se consideran alentadores para la proyeccion de unidades a escala industrial que puedan ser operadas con calor geotermico y/o solar.

  3. Modeling and design aspects of active caloric regenerators

    Science.gov (United States)

    Engelbrecht, Kurt

    2015-03-01

    A cooling device based on a solid caloric material using, for example, the elastocaloric, magnetocaloric, barocaloric or electrocaloric effect has the potential to replace vapor-compression based systems for a variety of applications. Any caloric device using a solid refrigerant may benefit from using a regenerative cycle to increase the operating temperature span. This presentation shows how all active caloric regenerators can be modeled using similar techniques and how they are related to passive regenerator performance. The advantages and disadvantages of using a regenerative cycle are also discussed. The issue of hysteresis in caloric materials is investigated from a system/thermodynamic standpoint and the effects on cooling power and efficiency are quantified using a numerical model of an active regenerator using model caloric materials with assumed properties. The implementation in a working device will be discussed for elastocaloric and magnetocaloric cooling devices. It is shown that demagnetization effects for magnetocaloric systems and stress concentration effects in elastocaloric system reduce the overall effect in the regenerator and care must be taken in regenerator design for both technologies. Other loss mechanisms outside the regenerator such as heat leaks are also discussed. Finally, experimental results for active magnetic regenerative cooler are given for a range of operating conditions. The most recently published device uses a regenerator consisting of Gd and three alloys of GdY and has demonstrated a COP over 3.

  4. Caloric restriction and exercise "mimetics'': Ready for prime time?

    Science.gov (United States)

    Handschin, Christoph

    2016-01-01

    Exercise and diet are powerful interventions to prevent and ameliorate various pathologies. The development of pharmacological agents that confer exercise- or caloric restriction-like phenotypic effects is thus an appealing therapeutic strategy in diseases or even when used as life-style and longevity drugs. Such so-called exercise or caloric restriction "mimetics" have so far mostly been described in pre-clinical, experimental settings with limited translation into humans. Interestingly, many of these compounds activate related signaling pathways, most often postulated to act on the common downstream effector peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in skeletal muscle. In this review, resveratrol and other exercise- and caloric restriction "mimetics" are discussed with a special focus on feasibility, chances and limitations of using such compounds in patients as well as in healthy individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. El clima de las ciudades: isla de calor de Salamanca

    Directory of Open Access Journals (Sweden)

    Mª Salud Alonso García

    2004-12-01

    Full Text Available En este trabajo se ha determinado la existencia de la isla de calor urbana (ICU, en una ciudad de tamaño medio, con un clima extremado y focos industriales de poca actividad. Con lo que se puede comprobar cómo afecta el calentamiento urbano a ciudades de estas características, pudiendo influir en los seres vivos de la zona. La existencia del fenómeno isla de calor, y su evolución en el tiempo, se han observado comparando los datos de temperatura registrados en una estación meteorológica situada en la ciudad, con los de otra estación fuera del radio de acción de la urbe, durante el período 1996-1998. Se han detectado dos fenómenos: la isla de calor nocturna, cuando la diferencia térmica entre la ciudad y la zona rural es positiva, que presenta sus valores más altos en otoño, y la isla de calor diurna, cuando la diferencia es negativa, que presenta sus valores más altos en primavera. Realizando un estudio estadístico de la evolución anual de la isla de calor nocturna en Salamanca, podemos definir isla de calor débil si su intensidad es inferior a 2 oC, moderada si se encuentra entre 2 oC y 4 oC e intensa si supera los 4 oC.

  6. Manejo prehospitalario de las lesiones causadas por el calor

    OpenAIRE

    Gómez Ruano, Juan Carlos

    2017-01-01

    Una de las mayores causas de morbilidad y mortalidad de personas cada verano en nuestro país y en todo el mundo son las enfermedades producidas por el calor, en especial el golpe de calor. Estas enfermedades son ocasionadas por exposiciones prolongadas al sol o a altas temperaturas que junto a otras causas como un consumo disminuido de líquidos, abuso de alcohol, utilización de demasiada ropa o ejercicio físico intenso pueden conducirnos a la muerte. Los primeros signos y síntomas de las e...

  7. Constrained caloric curves and phase transition for hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Borderie, B., E-mail: borderie@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Piantelli, S. [INFN Sezione di Firenze, 50019 Sesto Fiorentino (Italy); Rivet, M.F. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Raduta, Ad.R. [National Institute for Physics and Nuclear Engineering, RO-76900 Bucharest-Magurele (Romania); Ademard, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Bonnet, E. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Bougault, R. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Chbihi, A.; Frankland, J.D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Galichet, E. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Conservatoire National des Arts et Métiers, F-75141 Paris Cedex 03 (France); Gruyer, D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Guinet, D.; Lautesse, P. [Université Claude Bernard Lyon 1, Institut de Physique Nucléaire, CNRS-IN2P3, F-69622 Villeurbanne Cedex (France); Le Neindre, N.; Lopez, O. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Marini, P. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); and others

    2013-06-10

    Simulations based on experimental data obtained from multifragmenting quasi-fused nuclei produced in central {sup 129}Xe+{sup nat}Sn collisions have been used to deduce event by event freeze-out properties in the thermal excitation energy range 4–12 AMeV [S. Piantelli, et al., INDRA Collaboration, Nucl. Phys. A 809 (2008) 111]. From these properties and the temperatures deduced from proton transverse momentum fluctuations, constrained caloric curves have been built. At constant average volumes caloric curves exhibit a monotonic behaviour whereas for constrained pressures a backbending is observed. Such results support the existence of a first order phase transition for hot nuclei.

  8. Prevention of mammary tumorigenesis by intermittent caloric restriction: does caloric intake during refeeding modulate the response?

    Science.gov (United States)

    Cleary, Margot P; Hu, Xin; Grossmann, Michael E; Juneja, Subhash C; Dogan, Soner; Grande, Joseph P; Maihle, Nita J

    2007-01-01

    Chronic caloric restriction (CCR) prevents mammary tumorigenesis in rodents, but a protective effect for intermittent caloric restriction (ICR) is less well documented. We recently reported that ICR reduced mammary tumor (MT) incidence of mouse mammary tumor virus-transforming growth factor (MMTV-TGF)-alpha mice to a greater extent than did CCR. Here, we repeated this protocol and obtained serum and tissue samples. Ad libitum (AL) MMTV-TGF-alpha mice were fed AIN-93M diet. Beginning at 10 weeks of age, ICR mice received isocaloric AIN-93M-mod diet (2-fold increases in protein, fat, vitamins, and minerals) at 50% of ad libitum for 3 weeks followed by 3 weeks refeeding with AIN-93M diet. CCR mice were pair-fed AIN-93M:AIN-93M-mod (2:1) matching intakes for restriction/refeeding cycles. Mice were sacrificed for MT size, at 79 (end of 12th restriction) or at 80 (1 week after 12th refeeding) weeks of age. AL and ICR-80 mice had heavier body weights than ICR-79 and CCR mice (P food intakes of ICR and CCR mice were reduced 12% and 15% versus AL mice (P food than did AL mice during refeeding. MT incidence was 84%, 13%, and 27% for AL, ICR, and CCR mice, respectively. MT weight (P < 0.0011) and number (P < 0.01) were higher for AL mice compared with ICR and CCR mice. AL and ICR-80 mice had similar serum IGF-I levels, but only AL values were higher than those of ICR-79 and CCR mice (P < 0.0017). ICR mice had more MT DNA breaks compared with AL and CCR mice, suggesting enhanced apoptosis (P < 0.02). AL mice had higher mammary fat pad ObR and ObRb leptin receptor mRNA expression than did ICR and CCR mice (P < 0.001), but there was no effect on MTs. These results confirm that ICR prevents development of MTs to a greater extent than does CCR, although "overeating" during refeeding may compromise this protection.

  9. Apuntes de Transmisión del Calor

    OpenAIRE

    Martín Domingo, Agustín

    2013-01-01

    Esta publicacion está basada en unos apuntes para la parte de Transmisión del Calor de las asignaturas de la ETSAM. Sin embargo, con el tiempo se ha añadido otro material extra que excede ampliamente el contenido del curso.

  10. Dal calore all'entropia una introduzione alla termodinamica

    CERN Document Server

    Vicentini Missoni, Matilde

    1992-01-01

    Panta rei : processi ed equilibrio ; l'universo termodinamico : l'aspetto processuale ; il punto di vista dei processi come bilancio tra proprietà dell'equilibrio ; il fluire dell'energia ; automobili, frigoriferi e pompe di calore : informazioni tecnologiche ; e allora ? l'entropia ; la termostatica come teoria assiomatica ; la termodinamica dei processi.

  11. Mechanism-Based Modeling of Gastric Emptying Rate and Gallbladder Emptying in Response to Caloric Intake

    DEFF Research Database (Denmark)

    Guiastrennec, B; Sonne, David Peick; Hansen, M

    2016-01-01

    concentrations, and GBE was developed on data from 33 patients with type 2 diabetes and 33 matched nondiabetic individuals who were administered various test drinks. A feedback action of the caloric content entering the proximal small intestine was identified for the rate of GE. The cholecystokinin...... concentrations were not predictive of GBE, and an alternative model linking the nutrients amount in the upper intestine to GBE was preferred. Relative to fats, the potency on GBE was 68% for proteins and 2.3% for carbohydrates. The model predictions were robust across a broad range of nutritional content and may...

  12. Low-versus high-glycemic index diets in women: effects on caloric requirement, substrate utilization and insulin sensitivity.

    Science.gov (United States)

    Clapp, James F; Lopez, Beth

    2007-09-01

    Lowering dietary glycemic index appears to have positive health effects in obese and/or insulin resistant individuals. However, detailed studies in lean young men show no effect. This study was designed to test the null hypothesis that a diet rich in low-glycemic carbohydrate has no effect on lipid profile, caloric requirements, fat oxidation, or insulin sensitivity in adult women when compared to one rich in high-glycemic carbohydrate. The metabolic feeding protocol used was conducted in both a free-living and in-patient setting using a randomized crossover design. Seven women were studied on each of 2 diets in which 60% of the calories were from either high- or low-glycemic carbohydrate sources. Each diet lasted 20 days with measurements of caloric requirement, resting metabolic rate, glucose and insulin responses to diet and activity, insulin sensitivity, and lipid profile over the last 7 days. Caloric requirement was determined by bomb calorimetry. Other techniques included indirect calorimetry, hydrodensitometry, stable isotope tracers, and the euglycemic clamp. On the low-glycemic index diet the women's caloric requirements were 11% +/- 1% higher, fat oxidation at fasted rest supplied an average of 45% +/- 4% versus 28% +/- 5% of oxidative requirements, average glucose and insulin levels were approximately 40% lower, low density lipoproteins (LDL) and leptin concentrations were lower, and various indices of insulin sensitivity were > 20% higher. In this group of adult women, a diet that lowered glycemic index well below that typically found in western diets increased both daily caloric requirement and fat oxidation, decreased insulin and glucose concentrations and increased insulin sensitivity.

  13. Effect of solid-meal caloric content on gastric emptying kinetics of solids and liquids.

    Science.gov (United States)

    Urbain, J L; Siegel, J A; Mortelmans, L; van Cutsem, E; van den Maegdenbergh, V; de Roo, M

    1989-08-01

    In this study, we have evaluated the effect of the caloric content of a physiological test meal on the gastric emptying kinetics of solids and liquids. 22 healthy male volunteers were studied in two groups matched for age. After an overnight fast, each volunteer underwent the same test procedure; in the first group (G I), 10 volunteers received a meal consisting of bread, 111In-DTPA water and 1 scrambled egg labeled with 99mTc-labelled sulphur colloid; in the second group (G II) 12 volunteers were given the same meal but with 2 labeled eggs in order to increase the caloric content of the solid phase meal. Simultaneous anterior and posterior images were recorded using a dual-headed gamma camera. Solid and liquid geometric mean data were analyzed to determine the lag phase, the emptying rate and the half-emptying time for both solids and liquids. Solid and liquid gastric half-emptying times were significantly prolonged in G II compared to G I volunteers. For the solid phased, the delay was accounted for by a longer lag phase and a decrease in the equilibrium emptying rate. The emptying rate of the liquid phase was significantly decreased in G II compared to G I. Within each group, no statistically significant difference was observed between solid and liquid emptying rates. We conclude that the caloric content of the solid portion of a meal not only alters the emptying of the solid phase but also affects the emptying of the liquid component of the meal.

  14. Caloric Intake on the Sabbath: A Pilot Study of Contributing Factors to Obesity in the Orthodox Jewish Community.

    Science.gov (United States)

    Rosenberg, Deborah A; Swencionis, Charles; Segal-Isaacson, C J

    2016-10-01

    The American Orthodox Jewish community has specific cultural factors that may contribute to overweight and obesity. This study aimed to look at caloric intake on the Sabbath and its contribution to overweight and obesity. Twelve married or previously married women who identify themselves as Orthodox Jews were recruited to do 24-h food recalls over the phone. The participants were divided into three weight groups (normal, overweight, and obese) based on their BMI. The overweight and obese participants' data were combined into one group for the purposes of statistical testing. Paired t tests looking at the data for all participants showed significantly great caloric intake during an average Sabbath day than an average weekday [t(4) = 7.58, p Jewish community.

  15. Lost in processing? Perceived healthfulness, taste and caloric content of whole and processed organic food.

    Science.gov (United States)

    Prada, Marília; Garrido, Margarida V; Rodrigues, David

    2017-07-01

    The "organic" claim explicitly informs consumers about the food production method. Yet, based on this claim, people often infer unrelated food attributes. The current research examined whether the perceived advantage of organic over conventional food generalizes across different organic food types. Compared to whole organic foods, processed organic foods are less available, familiar and prototypical of the organic food category. In two studies (combined N = 258) we investigated how both organic foods types were perceived in healthfulness, taste and caloric content when compared to their conventional alternatives. Participants evaluated images of both whole (e.g., lettuce) and processed organic food exemplars (e.g., pizza), and reported general evaluations of these food types. The association of these evaluations with individual difference variables - self-reported knowledge and consumption of organic food, and environmental concerns - was also examined. Results showed that organically produced whole foods were perceived as more healthful, tastier and less caloric than those produced conventionally, thus replicating the well-established halo effect of the organic claim in food evaluation. The organic advantage was more pronounced among individuals who reported being more knowledgeable about organic food, consumed it more frequently, and were more environmentally concerned. The advantage of the organic claim for processed foods was less clear. Overall, processed organic (vs. conventional) foods were perceived as tastier, more healthful (Study 1) or equally healthful (Study 2), but also as more caloric. We argue that the features of processed food may modulate the impact of the organic claim, and outline possible research directions to test this assumption. Uncovering the specific conditions in which food claims bias consumer's perceptions and behavior may have important implications for marketing, health and public-policy related fields. Copyright © 2017 Elsevier

  16. The effect of a pre-load experiment on subsequent food consumption. Caloric and macronutrient intake in the days following a pre-load manipulation.

    Science.gov (United States)

    Timko, C Alix; Juarascio, Adrienne; Chowansky, Amy

    2012-04-01

    The current study was designed to test potential caloric and macronutrient counter-regulation or compensation amongst 76 participants who participated in a milkshake preload experiment. Participants completed food diaries for 2 days before and 2 days after participating in the pre-load experiment. It was hypothesized that dieters and restrained eaters might respond to the pre-load by compensating or counter-regulating food consumption during the rest of the day following the experiment, and on the 2 days post-experiment. Results indicated that there were no significant differences in caloric or macronutrient consumption between the experimental and control groups on the days after the experiment. There were also no interactions between restraint and dieting status and the experimental condition. However, there was a main effect of caloric intake across dieting status, with those dieting to lose weight showing lower caloric intake than those not dieting and those dieting to maintain weight. The results of this study suggests that disinhibitory food stimuli may be less powerful than once thought or relatively short acting, as long-term counter-regulation or compensation did not occur for most people. Overall, the current study provides additional insight into potential long term caloric counter-regulation or compensation in participants who participated in a preload experiment, but additional research is needed to better understand this phenomenon. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. DESARROLLOS INSTRUMENTALES EN MICROCALORIMETRIA DE CONDUCCIÓN DE CALOR

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo G.

    2010-09-01

    Full Text Available Se presentan aspectos generales de la microcalorimetría de conducción de calor. Se describe el diseño y la operación de microcalorímetros de conducción de calor estático y de flujo construidos en este laboratorio, los cuales fueron calibrados eléctrica y químicamente. Estos equipos se emplean en la caracterización de sólidos porosos por la técnica de calorimetría de inmersión y en la determinación de entalpias de transferencia de solutos; su uso se ilustra con algunos resultados típicos. Se mencionan además otras aplicaciones que se dan actualmente a estos aparatos.

  18. Perspective food addiction, caloric restriction, and dopaminergic neurotransmission

    DEFF Research Database (Denmark)

    Stankowska, Arwen Urrsula Malgorzata; Gjedde, Albert

    2013-01-01

    for a reduced cognitive reward condition. The combination of caloric restriction and food addiction imparts a high risk of relapse as a result of further reduction of dopaminergic neurotransmission and the subsequent loss of reward. As with drugs of abuse, ingestion of large quantities of sugar in circumstances...... by the relationship between dopamine receptor availability in the striatum and sensation-seeking in the form of an inverted U, suggested by recent findings, consistent with two opposite states of hypodopaminergic and hyperdopaminergic neuromodulation....

  19. Macronutrients and caloric intake in health and longevity

    OpenAIRE

    Solon-Biet, Samantha M.; Mitchell, Sarah J.; de Cabo, Rafael; Raubenheimer, David; Le Couteur, David G.; Simpson, Stephen J.

    2015-01-01

    Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of c...

  20. Is caloric restriction associated with development of eating-disorder symptoms? Results from the CALERIE trial.

    Science.gov (United States)

    Williamson, Donald A; Martin, Corby K; Anton, Stephen D; York-Crowe, Emily; Han, Hongmei; Redman, Leanne; Ravussin, Eric

    2008-01-01

    This study tested a secondary hypothesis of the CALERIE trial (Heilbronn et al., 2006) that a 12-month period of intentional dietary restriction would be associated with an increase in eating disorder symptoms. To test this hypothesis, 48 overweight adults were randomly assigned to four treatment arms in a 12-month study: (1) 25% calorie restriction, (2) 12.5% calorie restriction and 12.5% increased energy expenditure by structured exercise, (3) low-calorie diet, and (4) healthy diet (no-calorie restriction). Primary outcome measures for the study were changes in: eating disorder symptoms, mood, dietary restraint, body weight, and energy balance. All three dietary restriction arms were associated with increased dietary restraint and negative energy balance, but not with increased ED symptoms or other harmful psychological effects. Participants in the three calorie restriction arms lost significant amounts of body weight. The psychological and behavioral effects were maintained during a 6-month follow-up period. These results did not support the hypothesis that caloric restriction causes increased eating disorder symptoms in overweight adults. In general, caloric restriction had either benign or beneficial psychological and behavioral effects. (Copyright) 2008 APA.

  1. An In Vivo Magnetic Resonance Spectroscopy Study of the Effects of Caloric and Non-Caloric Sweeteners on Liver Lipid Metabolism in Rats

    NARCIS (Netherlands)

    Janssens, Sharon; Ciapaite, Jolita; Wolters, Justina C.; van Riel, Natal A.; Nicolay, Klaas; Prompers, Jeanine J.

    2017-01-01

    We aimed to elucidate the effects of caloric and non-caloric sweeteners on liver lipid metabolism in rats using in vivo magnetic resonance spectroscopy (MRS) and to determine their roles in the development of liver steatosis. Wistar rats received normal chow and either normal drinking water, or

  2. Remission of anosognosia for right hemiplegia and neglect after caloric vestibular stimulation.

    Science.gov (United States)

    Ronchi, Roberta; Rode, Gilles; Cotton, François; Farnè, Alessandro; Rossetti, Yves; Jacquin-Courtois, Sophie

    2013-01-01

    Neglect and related phenomena, as anosognosia for hemiplegia and somatoparaphrenia, are often associated to right-hemisphere lesions. These deficits can be alleviated by caloric vestibular stimulation, but little is known about the efficacy of this physiological intervention on neglect following left-hemisphere lesions. Here we report the case of an ambidextrous left brain-damaged patient with severe right personal and extrapersonal neglect, anosognosia for right hemiplegia and somatoparaphrenia. These symptoms co-occurred with more typical manifestations of left-brain damage, such as aphasia and apraxia. Neurological examination revealed right hemiplegia, hemianesthesia and hemianopia. Visuo-spatial tests for personal and extrapersonal neglect, as well as an anosognosia questionnaire, were submitted before and after caloric vestibular stimulation. Results showed a dramatic improvement of anosognosia for hemiplegia and neglect; no change was observed for the remaining deficits. The results confirm the notion of the selectivity of vestibular stimulation for neglect and related disorders and extend this notion by showing that similar effects can be obtained after lesion of the left hemisphere, suggesting that similar mechanisms are responsible for left- and right-sided neglect. Such a peculiar association of language and visuo-spatial disorders jointly present after a left-sided lesion opens the question of the link between handedness and lateralization of cognitive functions.

  3. Modeling body mass variation: incorporating social influence into calculations of caloric intake and energy expenditure.

    Science.gov (United States)

    Hernández-Hernández, Ana María; Huerta-Quintanilla, Rodrigo

    2014-01-01

    Variations in individual body mass and composition have long been a key focus in the health sciences, particularly now that overweight and obesity are considered as public health problems. We study a mathematical model that describes body mass variations which are determined by the energy balance between caloric intake and total energy expenditure. To calculate the change in caloric intake and energy expenditure over time, we proposed a relationship for each of these quantities, and we used measured values that are reported in the literature for the initial conditions. To account for small variations in the daily energy balance of an individual, we include social interactions as the multiplication of two terms: social proximity and social influence. We observe that social interactions have a considerable effect when the body mass of an individual is quite constant and social interactions take random values. However, when an individual's mass value changes (either increases or decreases), social interactions do not have a notable effect. In our simulation, we tested two different models that describe the body mass composition, and it resulted that one fits better the data.

  4. AMP activated protein kinase is indispensable for myocardial adaptation to caloric restriction in mice.

    Directory of Open Access Journals (Sweden)

    Kai Chen

    Full Text Available Caloric restriction (CR is a robust dietary intervention known to enhance cardiovascular health. AMP activated protein kinase (AMPK has been suggested to mediate the cardioprotective effects of CR. However, this hypothesis remains to be tested by using definitive loss-of-function animal models. In the present study, we subjected AMPKα2 knockout (KO mice and their wild type (WT littermates to a CR regimen that reduces caloric intake by 20%-40% for 4 weeks. CR decreased body weight, heart weight and serum levels of insulin in both WT and KO mice to the same degree, indicating the effectiveness of the CR protocol. CR activated cardiac AMPK signaling in WT mice, but not in AMPKα2 KO mice. Correspondingly, AMPKα2 KO mice had markedly reduced cardiac function during CR as determined by echocardiography and hemodynamic measurements. The compromised cardiac function was associated with increased markers of oxidative stress, endoplasmic reticulum stress and myocyte apoptosis. Mechanistically, CR down-regulated the expression of ATP5g2, a subunit of mitochondrial ATP synthase, and reduced ATP content in AMPKα2 KO hearts, but not in WT hearts. In addition, CR accelerated cardiac autophagic flux in WT mice, but failed to do so in AMPKα2 KO mice. These results demonstrated that without AMPK, CR triggers adverse effects that can lead to cardiac dysfunction, suggesting that AMPK signaling pathway is indispensible for energy homeostasis and myocardial adaptation to CR, a dietary intervention that normally produces beneficial cardiac effects.

  5. Can we live longer by eating less? A review of caloric restriction and longevity.

    Science.gov (United States)

    Roth, Lauren W; Polotsky, Alex J

    2012-04-01

    Caloric restriction, decreasing caloric intake by 20-30%, was first shown to extend life in rats nearly 80 years ago. Since that time, limiting food intake for longevity has been investigated in species from yeast to humans. In yeast and lower animals, caloric restriction has repeatedly been demonstrated to lengthen the life span. Studies of caloric restriction in non-human primates and in humans are ongoing and initial results suggest prolongation of life as well as prevention of age-related disease. There is also data in rodents suggesting that short term caloric restriction has beneficial effects on fertility. Although caloric restriction has many positive effects on health and longevity, quality of life on a restricted diet as well as the ability to maintain that diet long term are concerns that must be considered in humans. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. The Lexicocalorimeter: Gauging public health through caloric input and output on social media

    CERN Document Server

    Alajajian, S E; Reagan, A J; Alajajian, S C; Frank, M R; Mitchell, L; Lahne, J; Danforth, C M; Dodds, P S

    2015-01-01

    We propose and develop a Lexicocalorimeter: an online, interactive instrument for measuring the "caloric content" of social media and other large-scale texts. We do so by constructing extensive yet improvable tables of food and activity related phrases, and respectively assigning them with sourced estimates of caloric intake and expenditure. We show that for Twitter, our naive measures of "caloric input", "caloric output", and the ratio of these measures---"caloric balance"---are all strong correlates with health and well-being demographics for the contiguous United States. Our caloric balance measure outperforms both its constituent quantities, is tunable to specific demographic measures such as diabetes rates, provides a real-time signal reflecting a population's health, and has the potential to be used alongside traditional survey data in the development of public policy and collective self-awareness. Because our Lexicocalorimeter is a linear superposition of principled phrase scores, we also show we can m...

  7. Cognitive performances are selectively enhanced during chronic caloric restriction or resveratrol supplementation in a primate.

    Directory of Open Access Journals (Sweden)

    Alexandre Dal-Pan

    Full Text Available Effects of an 18-month treatment with a moderate, chronic caloric restriction (CR or an oral supplementation with resveratrol (RSV, a potential CR mimetic, on cognitive and motor performances were studied in non-human primates, grey mouse lemurs (Microcebus murinus.Thirty-three adult male mouse lemurs were assigned to three different groups: a control (CTL group fed ad libitum, a CR group fed 70% of the CTL caloric intake, and an RSV group (RSV supplementation of 200 mg.kg(-1.day(-1 fed ad libitum. Three different cognitive tests, two motor tests, one emotional test and an analysis of cortisol level were performed in each group.Compared to CTL animals, CR or RSV animals did not show any change in motor performances evaluated by rotarod and jump tests, but an increase in spontaneous locomotor activity was observed in both groups. Working memory was improved by both treatments in the spontaneous alternation task. Despite a trend for CR group, only RSV supplementation increased spatial memory performances in the circular platform task. Finally, none of these treatments induced additional stress to the animals as reflected by similar results in the open field test and cortisol analyses compared to CTL animals.The present data provided the earliest evidence for a beneficial effect of CR or RSV supplementation on specific cognitive functions in a primate. Taken together, these results suggest that RSV could be a good candidate to mimic long-term CR effects and support the growing evidences that nutritional interventions can have beneficial effects on brain functions even in adults.

  8. Cognitive Performances Are Selectively Enhanced during Chronic Caloric Restriction or Resveratrol Supplementation in a Primate

    Science.gov (United States)

    Marchal, Julia; Picq, Jean-Luc; Aujard, Fabienne

    2011-01-01

    Effects of an 18-month treatment with a moderate, chronic caloric restriction (CR) or an oral supplementation with resveratrol (RSV), a potential CR mimetic, on cognitive and motor performances were studied in non-human primates, grey mouse lemurs (Microcebus murinus). Thirty-three adult male mouse lemurs were assigned to three different groups: a control (CTL) group fed ad libitum, a CR group fed 70% of the CTL caloric intake, and an RSV group (RSV supplementation of 200 mg.kg−1.day−1) fed ad libitum. Three different cognitive tests, two motor tests, one emotional test and an analysis of cortisol level were performed in each group. Compared to CTL animals, CR or RSV animals did not show any change in motor performances evaluated by rotarod and jump tests, but an increase in spontaneous locomotor activity was observed in both groups. Working memory was improved by both treatments in the spontaneous alternation task. Despite a trend for CR group, only RSV supplementation increased spatial memory performances in the circular platform task. Finally, none of these treatments induced additional stress to the animals as reflected by similar results in the open field test and cortisol analyses compared to CTL animals. The present data provided the earliest evidence for a beneficial effect of CR or RSV supplementation on specific cognitive functions in a primate. Taken together, these results suggest that RSV could be a good candidate to mimic long-term CR effects and support the growing evidences that nutritional interventions can have beneficial effects on brain functions even in adults. PMID:21304942

  9. Macronutrients and caloric intake in health and longevity.

    Science.gov (United States)

    Solon-Biet, Samantha M; Mitchell, Sarah J; de Cabo, Rafael; Raubenheimer, David; Le Couteur, David G; Simpson, Stephen J

    2015-07-01

    Both lifespan and healthspan are influenced by nutrition, with nutritional interventions proving to be robust across a wide range of species. However, the relationship between nutrition, health and aging is still not fully understood. Caloric restriction is the most studied dietary intervention known to extend life in many organisms, but recently the balance of macronutrients has been shown to play a critical role. In this review, we discuss the current understanding regarding the impact of calories and macronutrient balance in mammalian health and longevity, and highlight the key nutrient-sensing pathways that mediate the effects of nutrition on health and ageing. © 2015 Society for Endocrinology.

  10. Effects of caloric restriction and overnight fasting on cycling endurance performance.

    Science.gov (United States)

    Ferguson, Lisa M; Rossi, Kelly A; Ward, Emily; Jadwin, Emily; Miller, Todd A; Miller, Wayne C

    2009-03-01

    In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

  11. Material-based figure of merit for caloric materials

    Science.gov (United States)

    Griffith, L. D.; Mudryk, Y.; Slaughter, J.; Pecharsky, V. K.

    2018-01-01

    The efficient use of reversible thermal effects in magnetocaloric, electrocaloric, and elastocaloric materials is a promising avenue that can lead to a substantially increased efficiency of refrigeration and heat pumping devices, most importantly, those used in household and commercial cooling applications near ambient temperature. A proliferation in caloric material research has resulted in a wide array of materials where only the isothermal change in entropy in response to a handful of different field strengths over a limited range of temperatures has been evaluated and reported. Given the abundance of such data, there is a clear need for a simple and reliable figure of merit enabling fast screening and down-selection to justify further detailed characterization of those material systems that hold the greatest promise. Based on the analysis of several well-known materials that exhibit vastly different magnetocaloric effects, the Temperature averaged Entropy Change is introduced as a suitable early indicator of the material's utility for magnetocaloric cooling applications, and its adoption by the caloric community is recommended.

  12. High monetary reward rates and caloric rewards decrease temporal persistence.

    Science.gov (United States)

    Fung, Bowen J; Bode, Stefan; Murawski, Carsten

    2017-02-22

    Temporal persistence refers to an individual's capacity to wait for future rewards, while forgoing possible alternatives. This requires a trade-off between the potential value of delayed rewards and opportunity costs, and is relevant to many real-world decisions, such as dieting. Theoretical models have previously suggested that high monetary reward rates, or positive energy balance, may result in decreased temporal persistence. In our study, 50 fasted participants engaged in a temporal persistence task, incentivised with monetary rewards. In alternating blocks of this task, rewards were delivered at delays drawn randomly from distributions with either a lower or higher maximum reward rate. During some blocks participants received either a caloric drink or water. We used survival analysis to estimate participants' probability of quitting conditional on the delay distribution and the consumed liquid. Participants had a higher probability of quitting in blocks with the higher reward rate. Furthermore, participants who consumed the caloric drink had a higher probability of quitting than those who consumed water. Our results support the predictions from the theoretical models, and importantly, suggest that both higher monetary reward rates and physiologically relevant rewards can decrease temporal persistence, which is a crucial determinant for survival in many species. © 2017 The Authors.

  13. Isla de calor en Toluca, México

    Directory of Open Access Journals (Sweden)

    Carlos Constantino Morales Méndez

    2007-01-01

    Full Text Available El clima de la ciudad de Toluca y del mundo ha sido modificado como consecuencia del crecimiento de su población y el aumento de las dimensiones de su distribución territorial. Las variaciones atmosféricas son más acusadas entre los espacios urbanos y rurales a medida que las ciudades son más grandes y su mancha urbana es más extensa,así como de la reducción de la vegetación, el aumento en la calefacción en casas y edificios y por la contaminación del aire. Para identificar los espacios con calor más intenso por la infraestructura urbana, se propone una metodología que consiste en la determinación de los valores de temperatura que se registraron en dos días típicos de invierno y verano, durante el día y la noche,mostrando la distribución de la isla de calor en la zona de estudio, a partir de los datos delas estaciones de la Red Automática de Monitoreo Ambiental (RAMA. Asimismo, se considera el comportamiento y variación de algunas variables atmosféricas como humedad relativa, precipitación y viento, para mostrar su comportamiento relativamente anómalo en la zona urbana.

  14. Role of sleep timing in caloric intake and BMI.

    Science.gov (United States)

    Baron, Kelly G; Reid, Kathryn J; Kern, Andrew S; Zee, Phyllis C

    2011-07-01

    Sleep duration has been linked to obesity and there is also an emerging literature in animals demonstrating a relationship between the timing of feeding and weight regulation. However, there is a paucity of research evaluating timing of sleep and feeding on weight regulation in humans. The goal of this study was to evaluate the role of sleep timing in dietary patterns and BMI. Participants included 52 (25 females) volunteers who completed 7 days of wrist actigraphy and food logs. Fifty-six percent were "normal sleepers" (midpoint of sleep ≥5:30 AM). Late sleepers had shorter sleep duration, later sleep onset and sleep offset and meal times. Late sleepers consumed more calories at dinner and after 8:00 PM, had higher fast food, full-calorie soda and lower fruit and vegetable consumption. Higher BMI was associated with shorter sleep duration, later sleep timing, caloric consumption after 8:00 PM, and fast food meals. In multivariate models, sleep timing was independently associated with calories consumed after 8:00 PM and fruit and vegetable consumption but did not predict BMI after controlling for sleep duration. Calories consumed after 8:00 PM predicted BMI after controlling for sleep timing and duration. These findings indicate that caloric intake after 8:00 PM may increase the risk of obesity, independent of sleep timing and duration. Future studies should investigate the biological and social mechanisms linking timing of sleep and feeding in order to develop novel time-based interventions for weight management.

  15. The effect of non-caloric sweeteners on cognition, choice, and post-consumption satisfaction.

    Science.gov (United States)

    Hill, Sarah E; Prokosch, Marjorie L; Morin, Amanda; Rodeheffer, Christopher D

    2014-12-01

    Consumers often turn to non-caloric sweeteners (NCS) as a means of promoting a healthy body weight. However, several studies have now linked their long-term use to increased weight gain, raising the question of whether these products produce unintended psychological, physiological, or behavioral changes that have implications for weight management goals. In the following, we present the results of three experiments bearing on this issue, testing whether NCS-consumption influences how individuals think about and respond to food. Participants in each of our three experiments were randomly assigned to consume a sugar-sweetened beverage, an unsweetened beverage, or a beverage sweetened with NCS. We then measured their cognition (Experiment 1), product choice (Experiment 2), and subjective responses to a sugar-sweetened food (Experiment 3). Results revealed that consuming NCS-sweetened beverages influences psychological processes in ways that - over time - may increase calorie intake. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Fugas de calor y aprovechamiento de efluentes en la optimización de ciclos Brayton totalmente irreversibles

    National Research Council Canada - National Science Library

    Herrera, C. A; Rosillo, M.E; Castaño

    2008-01-01

    ... (maquinas irreversibles, flujos disipativos, consumo de potencia en todo trasiego de fluídos, transmisiones de calor a gradientes de temperatura finitos, fugas de calor, desaprovechamiento de efluentes, restricciones en caídas de presión...

  17. Caloric requirements in patients with inflammatory bowel disease.

    Science.gov (United States)

    Barot, L R; Rombeau, J L; Feurer, I D; Mullen, J L

    1982-01-01

    Measured resting energy expenditure (REE) was compared to predicted basal energy expenditure (BEE) in 35 consecutive patients with nonseptic inflammatory bowel disease (IBD) and 20 healthy volunteers. Patients with IBD were groups greater or less than 90% ideal body weight (IBW). The BEE in kcal/day was found to be equivalent to the measured REE in both patient groups. It is suggested that the BEE be used to determine caloric requirements in nonseptic patients with inflammatory bowel disease. Patients less than 90% IBW had significantly higher measured energy expenditure (26.4 +/- 1.0) per kg body weight than either controls (21.2 +/- 0.7) or patients greater than or equal to 90% IBW (21.2 +/- 0.8), p less than 0.001. It is suggested that this increased expenditure is due to a combined effect of weight loss and intrinsic disease. PMID:7055399

  18. Caloric Restriction Promotes Structural and Metabolic Changes in the Skin

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Forni

    2017-09-01

    Full Text Available Caloric restriction (CR is the most effective intervention known to enhance lifespan, but its effect on the skin is poorly understood. Here, we show that CR mice display fur coat remodeling associated with an expansion of the hair follicle stem cell (HFSC pool. We also find that the dermal adipocyte depot (dWAT is underdeveloped in CR animals. The dermal/vennule annulus vasculature is enlarged, and a vascular endothelial growth factor (VEGF switch and metabolic reprogramming in both the dermis and the epidermis are observed. When the fur coat is removed, CR mice display increased energy expenditure associated with lean weight loss and locomotion impairment. Our findings indicate that CR promotes extensive skin and fur remodeling. These changes are necessary for thermal homeostasis and metabolic fitness under conditions of limited energy intake, suggesting a potential adaptive mechanism.

  19. Caloric restriction and the aging process: a critique.

    Science.gov (United States)

    Sohal, Rajindar S; Forster, Michael J

    2014-08-01

    The main objective of this review is to provide an appraisal of the current status of the relationship between energy intake and the life span of animals. The concept that a reduction in food intake, or caloric restriction (CR), retards the aging process, delays the age-associated decline in physiological fitness, and extends the life span of organisms of diverse phylogenetic groups is one of the leading paradigms in gerontology. However, emerging evidence disputes some of the primary tenets of this conception. One disparity is that the CR-related increase in longevity is not universal and may not even be shared among different strains of the same species. A further misgiving is that the control animals, fed ad libitum (AL), become overweight and prone to early onset of diseases and death, and thus may not be the ideal control animals for studies concerned with comparisons of longevity. Reexamination of body weight and longevity data from a study involving over 60,000 mice and rats, conducted by a National Institute on Aging-sponsored project, suggests that CR-related increase in life span of specific genotypes is directly related to the gain in body weight under the AL feeding regimen. Additionally, CR in mammals and "dietary restriction" in organisms such as Drosophila are dissimilar phenomena, albeit they are often presented to be the very same. The latter involves a reduction in yeast rather than caloric intake, which is inconsistent with the notion of a common, conserved mechanism of CR action in different species. Although specific mechanisms by which CR affects longevity are not well understood, existing evidence supports the view that CR increases the life span of those particular genotypes that develop energy imbalance owing to AL feeding. In such groups, CR lowers body temperature, rate of metabolism, and oxidant production and retards the age-related pro-oxidizing shift in the redox state. Copyright © 2014 The Authors. Published by Elsevier Inc. All

  20. Low Caloric Sweeteners for Diabetes and Obesity Care and Their

    Directory of Open Access Journals (Sweden)

    Mohammad Asif

    2015-10-01

    Full Text Available Diabetes and obesity are two common human disorders that affecting human health and invite various diseases and disorders in normal body functions. These diseases are very common worldwide. Diabetes occurs when high blood sugar levels develop. This happens when body can’t make and use all of the insulin it needs to blood sugar normally to keep blood sugar levels as normal as possible to control diabetes. Diabetic patients will need to follow a diet plan, do exercise and possibly take insulin injections. As part of eating plan, health care provider, and dietitian may ask to limit the amount of carbohydrates eat each day. Low-calorie sweeteners are one easy tool to help for follow eating plan. Obesity is more susceptible and often been associated with frequent ingestion of high energy food in high amount and high intake of sugars such as fermentable sugars such as sucrose, fructose, glucose, and maltose. Both diseases are may be genetically or due to hormonal imbalances. High energy sweeteners may causes caries in the teeth particularly susceptible to the children. Increased calorie intake associated with sugars and carbohydrates, especially when associated with physical inactivity, has been implicated in obesity. Fortunately, low calorie artificial and natural alternatives of sugars have been developed as alternatives to fermentable sugars and have shown promise in these health issues. Although there are only few artificial sweeteners (saccharin, aspartame, acesulfam potassium, sucralose, cyclamate that have been approved as food additives by the Food and Drug Administration and additional other low-caloric sweeteners (sugar alcohols, neotame, stevia, erythritol, xylitol, tagatose that have FDA-generally recognized as safe. Given the health impact of sugars and other carbohydrates, professionals should be aware of the marketed available low caloric sweeteners and both their benefits and potential risks.

  1. The effect of alternate-day caloric restriction on the metabolic consequences of eight days' bed rest in healthy lean men

    DEFF Research Database (Denmark)

    Harder-Lauridsen, Nina Majlund; Nielsen, Signe Tellerup; Porsdam Mann, Sebastian

    2017-01-01

    BACKGROUND: Physical activity and alternate-day fasting/caloric restriction may both ameliorate aspects of the metabolic syndrome, such as insulin resistance, visceral fat mass accumulation, and cognitive impairment, by overlapping mechanisms. OBJECTIVE: To test the hypothesis that alternate-day...... caloric restriction (ADCR) with overall energy balance would reduce insulin resistance and accumulation of visceral fat, in addition to improving cognitive functions, after eight consecutive days in bed. DESIGN: Healthy, lean men (n = 20) were randomized to 1) 8 days' bed rest with 3 daily iso......-energetic meals (control group, n = 10); and 2) 8 days' bed rest with 25% of total energy requirements every other day and 175% of total energy requirements every other day (ADCR group). Oral glucose tolerance testing, DXA scans, magnetic resonance imaging of the abdomen and brain, VO2 max, and tests...

  2. Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea

    Science.gov (United States)

    Young, Jordann K.; Black, Bryan A.; Clarke, Janet T.; Schonberg, Susan V.; Dunton, Kenneth H.

    2017-10-01

    The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific walrus (Odobenus rosmarus divergens). Bivalves were collected over four cruises in the northeastern Chukchi Sea (2009, 2010, 2012, 2013). Our samples were largely dominated by calorie-dense, deposit-feeding species, including Macoma spp., Ennucula tenuis, Nuculana spp. and Yoldia spp. Weight-frequency distributions were strongly right-skewed for most taxa, though some showed evidence of a bimodal distribution. Caloric densities as measured through bomb calorimetry significantly differed among taxa (ANOVA F = 32.57, df = 9, p-valueanimal wet weight was found to be a reliable predictor of whole animal caloric content. Bivalve populations and peak caloric densities were centered on and to the southeast of Hanna Shoal, which coincided with peak Pacific walrus relative density (walruses per km surveyed) from July through October. Significant differences in mean caloric values were found between areas with and without walruses present (student's t-test, t=-2.9088, df = 252.24, p-value = 0.003952), as well as between areas with low and high walrus relative densities in the pooled annual dataset and in each individual month except October (ANOVA, p-value<0.05). The high-calorie deposit feeders that dominate these bivalve communities preferentially consume food sources, such as sea ice algae, that are likely to be affected by shifting sea ice dynamics. As such, continued warming has the potential to alter bivalve communities in the northeastern Chukchi Sea, which may have profound implications for upper trophic levels.

  3. Laboratório caseiro: calorímetro de baixo custo

    OpenAIRE

    Laburú, Carlos Eduardo; UEL - Párana; Rodrigues, Rogério; UEL - Paraná

    1998-01-01

    Este trabalho propõe a construção de um calorímetro de baixo custo, de montagem simples e com materiais facilmente encontrados. Objetiva- se com o calorímetro proposto substituir os normalmente utilizados nos laboratórios de física do secundário. Examina-se a capacidade térmica e o isolamento térmico do calorímetro proposto, comparando-o com um comercial muito utilizado nas escolas.

  4. Prácticas de Física: Calor de fusión

    OpenAIRE

    Beléndez,Augusto; Bernabeu, Guillermo; Vera Guarinos, Jenaro; Pastor Antón, Carlos; Martín García, Agapito

    1988-01-01

    El objetivo de esta práctica de laboratorio es la determinación del calor latente de fusión del hielo mediante el método de las mezclas así como el aprendizaje del manejo del calorímetro como instrumento de trabajo en experiencias térmicas, fundamentalmente de calorimetría. Para desarrollar la experiencia se introduce en un calorímetro una cierta cantidad de líquido a una temperatura superior a la del ambiente y luego añadir una cantidad de hielo a su temperatura de fusión. Es necesario conoc...

  5. Impacto ecológico de los intercambiadores de calor de tubo y coraza

    OpenAIRE

    Reyes–Rodríguez, Maida Bárbara; Moya Rodríguez, Jorge Laureano; Cruz Fonticiella, Oscar Miguel

    2014-01-01

    Los intercambiadores de calor del tipo de coraza y tubo constituyen uno de los equipos más importantes en las plantas de procesos químicos. El diseño de los intercambiadores de calor desde el punto de vista termodinámico se basa en dos aspectos fundamentales, el coeficiente global de transferencia de calor y la caída de presión total. En el año 2007 el Científico chino Guo estableció una nueva propiedad termodinámica denominada “Entransía”, la cual expresa la capacidad de un cuerpo de transfe...

  6. Research and technological development on heat pumps in Mexico operating with geothermal energy; Investigacion y desarrollo tecnologico sobre bombas de calor en Mexico operando con energia geotermica

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Gutierrez, Alfonso; Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    The Instituto de Investigaciones Electricas (IIE) and the Comision Federal de Electricidad (CFE) carried out in the past an extensive work of research and development (R&D) on heat pumps (HP). The systems tried on include heat pumps by mechanical compression, thermal absorption and thermal transformers. This paper briefly describes the main aspects of R&D on heat pumps and presents a more detailed description of three of the main studies: a) a Heat Pump (HP) by mechanical compression water-water type, designed for brine purification, operating with low pressure geothermal steam at the geothermal field Los Azufres, Michoacan, Mexico; b) a HP by absorption for cooling and refrigeration, operating with ammoniac/water and low enthalpy geothermal energy, which was tested in the geothermal fields of Los Azufres, Michoacan and Cerro Prieto, Baja California, and c) a thermal transformer by absorption, named Heat Pump by Absorption Type 2, which was tested to evaluate the behavior of diverse ternary solutions as working fluids. To date, there are plans to install and test a geothermal heat pump (connected to the subsoil), in Cerro Prieto, Mexicali, Baja California, Mexico. [Spanish] El Instituto de Investigaciones Electricas (IIE) y la Comision Federal de Electricidad (CFE) realizaron un trabajo extenso de investigacion y desarrollo (I&D) sobre bombas de calor (BC) en el pasado. Los sistemas que se probaron incluyen bombas de calor por compresion mecanica, absorcion y transformadores termicos. Este trabajo describe brevemente los principales aspectos de I&D sobre bombas de calor y se da una descripcion mas detallada de tres de los principales estudios: a) una Bomba de Calor (BC) por compresion mecanica tipo agua-agua, disenada para purificacion de salmueras, operando con vapor geotermico de baja presion en el campo geotermico de Los Azufres, Michoacan; b) una BC por absorcion para enfriamiento y refrigeracion, operando con amoniaco/agua y energia geotermica de baja entalpia

  7. Caloric intake and Alzheimer's disease. Experimental approaches and therapeutic implications.

    Science.gov (United States)

    Pasinetti, Giulio Maria; Zhao, Zhong; Qin, Weiping; Ho, Lap; Shrishailam, Yemul; Macgrogan, Donal; Ressmann, Wendy; Humala, Nelson; Liu, Xunxian; Romero, Carmen; Stetka, Breton; Chen, Linghong; Ksiezak-Reding, Hanna; Wang, Jun

    2007-01-01

    Alzheimer's disease (AD) is a rapidly growing public health concern with potentially devastating effects. Presently, there are no known cures or effective preventive strategies. While genetic factors are relevant in early-onset cases, they appear to play less of a role in late-onset sporadic AD cases, the most common form of AD. Due to the fact that the disease typically strikes very late in life, delaying symptoms could be as good as a cure for many people. For example, it is now widely accepted that if the onset of the disease could be delayed by even 5 years, the incidence could be cut in half. Both clinical and epidemiological evidence suggests that modification of lifestyle factors such as nutrition may prove crucial to AD management given the mounting experimental evidence suggesting that brain cells are remarkably responsive to "what somebody is doing". Among other nongenetic factors influencing AD, recent studies strongly support the evidence that caloric intake may play a role in the relative risk for AD clinical dementia. Indeed, the effect of diet in AD has been an area of research that has produced promising results, at least experimentally. Most importantly, as mechanistic pathways are defined and their biochemical functions scrutinized, the evidence supporting a direct link between nutrition and AD neuropathology continues to grow. Our work, as well as that of others, has recently resulted in the development of experimental dietary regimens that might promote, attenuate or even reverse features of AD. Most remarkably, while we found that high caloric intake based on saturated fat promotes AD type Beta-amyloidosis, conversely we found that dietary restriction based on reduced carbohydrate intake is able to prevent it. This evidence is very exciting and is, in part, consistent with current epidemiological studies suggesting that obesity and diabetes are associated with a >4-fold increased risk of developing AD. The clarification of the mechanisms

  8. Relationship between caloric intake and length of hospital stay for infants with bronchiolitis.

    Science.gov (United States)

    Weisgerber, Michael C; Lye, Patricia S; Nugent, Melodee; Li, Shun-Hwa; De Fouw, Kari; Gedeit, Rainer; Simpson, Pippa; Gorelick, Marc H

    2013-01-01

    Poor oral intake is a common presenting symptom among infants hospitalized with bronchiolitis. The prevalence, degree, and duration of iminished caloric intake in these infants have not been studied. Our goal was to determine the daily caloric intake among infants admitted with bronchiolitis and to evaluate the relationship between early hospital caloric intake and length of stay (LOS). We conducted a retrospective chart review of infants aged or =183 days. Caloric intake was diminished in the early course of hospitalization for infants who had bronchiolitis and slowest to normalize in infants with the longest LOS. Interventions aimed at decreasing LOS among infants admitted with bronchiolitis should consider the potential significance of nutrition for severely affected infants with this condition.

  9. Palatable Hyper-Caloric Foods Impact on Neuronal Plasticity.

    Science.gov (United States)

    Morin, Jean-Pascal; Rodríguez-Durán, Luis F; Guzmán-Ramos, Kioko; Perez-Cruz, Claudia; Ferreira, Guillaume; Diaz-Cintra, Sofia; Pacheco-López, Gustavo

    2017-01-01

    Neural plasticity is an intrinsic and essential characteristic of the nervous system that allows animals "self-tuning" to adapt to their environment over their lifetime. Activity-dependent synaptic plasticity in the central nervous system is a form of neural plasticity that underlies learning and memory formation, as well as long-lasting, environmentally-induced maladaptive behaviors, such as drug addiction and overeating of palatable hyper-caloric (PHc) food. In western societies, the abundance of PHc foods has caused a dramatic increase in the incidence of overweight/obesity and related disorders. To this regard, it has been suggested that increased adiposity may be caused at least in part by behavioral changes in the affected individuals that are induced by the chronic consumption of PHc foods; some authors have even drawn attention to the similarity that exists between over-indulgent eating and drug addiction. Long-term misuse of certain dietary components has also been linked to chronic neuroimmune maladaptation that may predispose individuals to neurodegenerative conditions such as Alzheimer's disease. In this review article, we discuss recent evidence that shows how consumption of PHc food can cause maladaptive neural plasticity that converts short-term ingestive drives into compulsive behaviors. We also discuss the neural mechanisms of how chronic consumption of PHc foods may alter brain function and lead to cognitive impairments, focusing on prenatal, childhood and adolescence as vulnerable neurodevelopmental stages to dietary environmental insults. Finally, we outline a societal agenda for harnessing permissive obesogenic environments.

  10. Fasting and Caloric Restriction in Cancer Prevention and Treatment.

    Science.gov (United States)

    Brandhorst, Sebastian; Longo, Valter D

    Cancer is the second leading cause of death in the USA and among the leading major diseases in the world. It is anticipated to continue to increase because of the growth of the aging population and prevalence of risk factors such as obesity, smoking, and/or poor dietary habits. Cancer treatment has remained relatively similar during the past 30 years with chemotherapy and/or radiotherapy in combination with surgery remaining the standard therapies although novel therapies are slowly replacing or complementing the standard ones. According to the American Cancer Society, the dietary recommendation for cancer patients receiving chemotherapy is to increase calorie and protein intake. In addition, there are no clear guidelines on the type of nutrition that could have a major impact on cancer incidence. Yet, various forms of reduced caloric intake such as calorie restriction (CR) or fasting demonstrate a wide range of beneficial effects able to help prevent malignancies and increase the efficacy of cancer therapies. Whereas chronic CR provides both beneficial and detrimental effects as well as major compliance challenges, periodic fasting (PF), fasting-mimicking diets (FMDs), and dietary restriction (DR) without a reduction in calories are emerging as interventions with the potential to be widely used to prevent and treat cancer. Here, we review preclinical and preliminary clinical studies on dietary restriction and fasting and their role in inducing cellular protection and chemotherapy resistance.

  11. Coeficientes de transferencia de calor y pérdida de eficiencia en intercambiadores de calor de placas durante el enfriamiento del licor amoniacal

    OpenAIRE

    Enrique Torres-Tamayo; Luís E. Quintana-Charlot; Orlando Vega-Arias; Yoalbys Retirado-Mediaceja

    2011-01-01

    En la planta de Recuperación de Amoniaco de la empresa niquelera Ernesto Che Guevara la pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, se asocia a la incorrecta estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio; lo anterior incrementa el consumo de agua, la energía disponible en el sistema y los costos de mantenimiento. Se realizó una invest...

  12. Comportamentos das Famílias Portuguesas em Épocas de Calor e Durante a Onda de Calor de Agosto de 2003

    OpenAIRE

    Nogueira, Paulo; Paixão, Eleonora; Falcão, José Marinho

    2005-01-01

    Este estudo teve como principal objectivo a caracterização das atitudes e da adopção de medidas de protecção em períodos de calor e em particular conhecer aquelas que efectivamente foram adoptadas durante a onda de calor de Agosto de 2003 (29 de Julho a 15 de Agosto). Foi realizado um inquérito por via postal, aplicando um questionário aos indivíduos de 18 e mais anos das unidades de alojamento (UA), que constituem a amostra ECOS (Em Casa Observamos Saúde) do Observatório Nacional de Saúd...

  13. Comportamentos das famílias portuguesas em épocas de calor e durante a onda de calor de Agosto de 2003

    OpenAIRE

    Nogueira, Paulo Jorge; Paixão, Eleonora de Jesus; Falcão, José Marinho

    2005-01-01

    RESUMO - Este estudo teve como principal objectivo a caracterização das atitudes e da adopção de medidas de protecção em períodos de calor e em particular conhecer aquelas que efectivamente foram adoptadas durante a onda de calor de Agosto de 2003 (29 de Julho a 15 de Agosto). Foi realizado um inquérito por via postal, aplicando um questionário aos indivíduos de 18 e mais anos das unidades de alojamento (UA), que constituem a amostra ECOS (Em Casa Observamos Saúde) do ...

  14. Use of caloric and noncaloric sweeteners in US consumer packaged foods, 2005-2009.

    Science.gov (United States)

    Ng, Shu Wen; Slining, Meghan M; Popkin, Barry M

    2012-11-01

    Our understanding of the use of caloric and noncaloric sweeteners in the US food supply is limited. This study uses full ingredient list and Nutrition Facts label data from Gladson Nutrition Database and nationally representative purchases of consumer packaged foods from Nielsen Homescan in 2005 through 2009 to understand the use of caloric sweeteners (including fruit juice concentrate) and noncaloric sweeteners in consumer packaged foods. Of the 85,451 uniquely formulated foods purchased during 2005 through 2009, 75% contain sweeteners (68% with caloric sweetener only, 1% with noncaloric sweetener only, 6% with both caloric and noncaloric sweeteners). Caloric sweetener are in >95% of cakes/cookies/pies, granola/protein/energy bars, ready-to-eat cereals, sweet snacks, and sugar-sweetened beverages. Noncaloric sweetener are in >33% of yogurts and sport/energy drinks, 42% of waters (plain or flavored), and most dietetic sweetened beverages. Across unique products, corn syrup is the most commonly listed sweetener, followed by sorghum, cane sugar, high-fructose corn syrup, and fruit juice concentrate. Also, 77% of all calories purchased in the United States in 2005-2009 contained caloric sweeteners and 3% contained noncaloric sweeteners, and 73% of the volume of foods purchased contained caloric sweetener and 15% contained noncaloric sweetener. Trends during this period suggest a shift toward the purchase of noncaloric sweetener-containing products. Our study poses a challenge toward monitoring sweetener consumption in the United States by discussing the need and options available to improve measures of caloric sweetener and noncaloric sweetener and additional requirements on Nutrition Facts labels on consumer packaged foods. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  15. Caloric restriction decreases orthostatic tolerance independently from 6° head-down bedrest.

    Directory of Open Access Journals (Sweden)

    John P Florian

    Full Text Available Astronauts consume fewer calories during spaceflight and return to earth with an increased risk of orthostatic intolerance. Whether a caloric deficiency modifies orthostatic responses is not understood. Thus, we determined the effects of a hypocaloric diet (25% caloric restriction during 6° head down bedrest (an analog of spaceflight on autonomic neural control during lower body negative pressure (LBNP. Nine healthy young men completed a randomized crossover bedrest study, consisting of four (2 weeks each interventions (normocaloric bedrest, normocaloric ambulatory, hypocaloric bedrest, hypocaloric ambulatory, each separated by 5 months. Muscle sympathetic nerve activity (MSNA was recorded at baseline following normocaloric and hypocaloric interventions. Heart rate (HR and arterial pressure were recorded before, during, and after 3 consecutive stages (7 min each of LBNP (-15, -30, -45 mmHg. Caloric and posture effects during LBNP were compared using two-way ANOVA with repeated measures. There was a strong trend toward reduced basal MSNA following caloric restriction alone (normcaloric vs. hypocaloric: 22±3 vs. 14±4 burst/min, p = 0.06. Compared to the normocaloric ambulatory, both bedrest and caloric restriction were associated with lower systolic blood pressure during LBNP (p<0.01; however, HR responses were directionally opposite (i.e., increase with bedrest, decrease with caloric restriction. Survival analysis revealed a significant reduction in orthostatic tolerance following caloric restriction (normocaloric finishers: 12/16; hypocaloric finishers: 6/16; χ2, p = 0.03. Caloric restriction modifies autonomic responses to LBNP, which may decrease orthostatic tolerance after spaceflight.

  16. The comparative effect of fasting with and without caloric restriction in Rat on oxidative stress parameters

    OpenAIRE

    Nurina Tyagita; Taufiqurrachman Nasihun; Titiek Sumarawati

    2016-01-01

    Introduction: Fasting, like Islamic Ramadan Fasting, has been associated with health benefits. Islamic Ramadan fasting, a form of caloric restriction (CR) or alternate day fasting that. Studies suggest a comparable effect of ADF and caloric restriction. Despite the fact that fasting can be considered as a form of dietary restriction, fasters tend to have difficulty to reduce their food intake during non-fasting period by overeating leading to the excessive calorie intake. To compare the effec...

  17. Weight Cycling and Cancer: Weighing the Evidence of Intermittent Caloric Restriction and Cancer Risk

    OpenAIRE

    Henry J. Thompson; McTiernan, Anne

    2011-01-01

    Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adv...

  18. Effects of immobilisation and caloric restriction on antioxidant parameters and T-cell apoptosis in healthy young men

    Science.gov (United States)

    Ellinger, S.; Arendt, B. M.; Boese, A.; Juschus, M.; Schaefer, S.; Stoffel-Wagner, B.; Goerlich, R.

    Background: Astronauts are exposed to oxidative stress due to radiation and microgravity, which might impair immune functions. Effects of hypocaloric nutrition as often observed in astronauts on oxidative stress and immune functions are not clear. We investigated, if microgravity, simulated by 6 Head-down tilt (HDT) and caloric restriction (-25%, fat reduced) with adequate supply of micronutrients affect DNA-damage in peripheral leukocytes, antioxidant parameters in plasma, and T-cell apoptosis. Material & Methods: 10 healthy male non-smokers were subjected to 4 different interventions (normocaloric diet or caloric restriction (CR) in upright position (UP) or HDT) for 14 days each (cross-over). DNA-damage in peripheral leukocytes (Comet Assay), trolox equivalent antioxidant capacity (TEAC) and uric acid in plasma were measured before, after 5, 10, and 13 days of intervention, and after 2 days recovery. T-cell apoptosis (Annexin V binding test) was assessed before and after intervention. Results: Preliminary results show that only endogenous, but not ex vivo H2O2-induced DNA strand breaks were reduced by CR compared to normocaloric diet. In upright position, endogenous DNA strand breaks decreased continuously during CR, reaching significance after recovery. During HDT, caloric restriction seems to counteract a temporary increase in DNA strand breaks observed in subjects receiving normocaloric diet. TEAC was reduced during HDT compared to UP in subjects under caloric restriction. An increase in plasma uric acid related to intervention occurred only after 5 days HDT in CR vs. normocaloric diet. T-cell apoptosis was not affected by any kind of intervention. Conclusion: Neither HDT nor CR with sufficient supply of micronutrients seem to induce oxidative stress or T-cell apoptosis in healthy young men. In contrast, CR might prevent endogenous DNA-damage in peripheral leukocytes. As DNA-damage is a risk factor for carcinogenesis, protective effects of energy reduction are

  19. Fatores associados à intensidade das ondas de calor em mulheres em climatério Factors associated with the intensity of hot flashes in climacteric women

    Directory of Open Access Journals (Sweden)

    Danielle Santos-Sá

    2006-12-01

    Full Text Available OBJETIVO: Identificar os fatores associados à intensidade das ondas de calor em mulheres climatéricas em Campinas, São Paulo. MÉTODOS: Análise secundária de banco de dados de estudo descritivo de coorte transversal, de base populacional. Foram selecionadas 334 mulheres com ondas de calor, por amostragem, entre 45-60 anos. Os dados foram coletados por meio de entrevistas domiciliares, com questionários estruturados e pré-testados, fornecidos pela Fundação Internacional de Saúde/Sociedade Internacional de Menopausa, Sociedade Norte-Americana de Menopausa, e adaptados pelos autores, e a intensidade das ondas de calor mensurada por meio do índice circulatório. Avaliou-se a idade, uso de métodos anticoncepcionais, terapia hormonal, laqueadura tubária, índice de massa corpórea, estado menopausal, tempo de menopausa, antecedente de histerectomia, ooforectomia bilateral e tabagismo. Calculou-se a mediana e as freqüências absolutas e relativas, de acordo com o tipo de variável. A medida de associação foi a razão de prevalência (RP. Realizou-se análise bivariada e de regressão múltipla para identificação dos fatores associados à intensidade das ondas de calor, com intervalo de confiança de 95% (IC 95%. RESULTADOS: Mulheres com tempo de menopausa superior a 61 meses (RP: 0,59; IC 95 %: 0,39-0,88 apresentaram chance significativamente menor de referir ondas de calor intensas enquanto o antecedente de ooforectomia bilateral (RP: 1,95; IC 95%: 1,08-3,50 associou-se significativamente à intensidade das ondas de calor. CONCLUSÃO: Os fatores associados às ondas de calor de maior intensidade, tempo de menopausa e ooforectomia bilateral sugerem o hipoestrogenismo como causa comum para as ondas de calor intensas. Mulheres com esses fatores devem receber atenção especializada, minimizando as repercussões negativas das ondas de calor.OBJECTIVE: To identify factors associated with the intensity of hot flashes in 334 climacteric

  20. Alleviation of senescence and epithelial-mesenchymal transition in aging kidney by short-term caloric restriction and caloric restriction mimetics via modulation of AMPK/mTOR signaling.

    Science.gov (United States)

    Dong, Dan; Cai, Guang-Yan; Ning, Yi-Chun; Wang, Jing-Chao; Lv, Yang; Hong, Quan; Cui, Shao-Yuan; Fu, Bo; Guo, Ya-Nan; Chen, Xiang-Mei

    2017-03-07

    Renal fibrosis contributes to declining renal function in the elderly. What is unclear however, is whether epithelial-mesenchymal transition (EMT) contributes to this age-related renal fibrosis. Here, we analyzed indicators of EMT during kidney aging and investigated the protective effects and mechanisms of short-term regimens of caloric restriction (CR) or caloric restriction mimetics (CRMs), including resveratrol and metformin. High glucose was used to induce premature senescence and EMT in human primary proximal tubular cells (PTCs) in vitro. To test the role of AMPK-mTOR signaling, siRNA was used to deplete AMPK. Cellular senescence and AMPK-mTOR signaling markers associated with EMT were detected. CR or CRMs treatment alleviated age-related EMT in aging kidneys, which was accompanied by activation of AMPK-mTOR signaling. High glucose induced premature senescence and EMT in PTCs in vitro, which was accompanied by down-regulation of AMPK/mTOR signaling. CRMs alleviated high glucose-induced senescence and EMT via stimulation of AMPK/mTOR signaling. Activation of AMPK/mTOR signaling protected PTCs from high glucose-induced EMT and cellular senescence. Short-term regimens of CR and CRMs alleviated age-related EMT via AMPK-mTOR signaling, suggesting a potential approach to reducing renal fibrosis during aging.

  1. Palatable Hyper-Caloric Foods Impact on Neuronal Plasticity

    Science.gov (United States)

    Morin, Jean-Pascal; Rodríguez-Durán, Luis F.; Guzmán-Ramos, Kioko; Perez-Cruz, Claudia; Ferreira, Guillaume; Diaz-Cintra, Sofia; Pacheco-López, Gustavo

    2017-01-01

    Neural plasticity is an intrinsic and essential characteristic of the nervous system that allows animals “self-tuning” to adapt to their environment over their lifetime. Activity-dependent synaptic plasticity in the central nervous system is a form of neural plasticity that underlies learning and memory formation, as well as long-lasting, environmentally-induced maladaptive behaviors, such as drug addiction and overeating of palatable hyper-caloric (PHc) food. In western societies, the abundance of PHc foods has caused a dramatic increase in the incidence of overweight/obesity and related disorders. To this regard, it has been suggested that increased adiposity may be caused at least in part by behavioral changes in the affected individuals that are induced by the chronic consumption of PHc foods; some authors have even drawn attention to the similarity that exists between over-indulgent eating and drug addiction. Long-term misuse of certain dietary components has also been linked to chronic neuroimmune maladaptation that may predispose individuals to neurodegenerative conditions such as Alzheimer’s disease. In this review article, we discuss recent evidence that shows how consumption of PHc food can cause maladaptive neural plasticity that converts short-term ingestive drives into compulsive behaviors. We also discuss the neural mechanisms of how chronic consumption of PHc foods may alter brain function and lead to cognitive impairments, focusing on prenatal, childhood and adolescence as vulnerable neurodevelopmental stages to dietary environmental insults. Finally, we outline a societal agenda for harnessing permissive obesogenic environments. PMID:28261067

  2. Cardioprotective Signature of Short-Term Caloric Restriction.

    Directory of Open Access Journals (Sweden)

    Hossein Noyan

    Full Text Available To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR.Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we reveal the pathways that are modulated by short-term CR, which are associated with protection of the mouse heart from ischemia.Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL diet with free access to regular chow, or CR, receiving 30% less food for 7 days (d, prior to myocardial infarction (MI via permanent coronary ligation. At d8, the left ventricles (LV of AL and CR mice were collected for Western blot, mRNA and microRNA (miR analyses to identify cardioprotective gene expression signatures. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI.This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01. mRNA and miR profiles pre-MI (N=5/group identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM. Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38. CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

  3. Replacing sweetened caloric beverages with drinking water is associated with lower energy intake.

    Science.gov (United States)

    Stookey, Jodi D; Constant, Florence; Gardner, Christopher D; Popkin, Barry M

    2007-12-01

    Reduced intake of sweetened caloric beverages (SCBs) is recommended to lower total energy intake. Replacing SCBs with non-caloric diet beverages does not automatically lower energy intake, however. Compensatory increases in other food or beverages reportedly negate benefits of diet beverages. The purpose of this study was to evaluate drinking water as an alternative to SCBs. Secondary analysis of data from the Stanford A TO Z intervention evaluated change in beverage pattern and total energy intake in 118 overweight women (25 to 50 years) who regularly consumed SCBs (>12 ounces/d) at baseline. At baseline and 2, 6, and 12 months, mean daily beverage intake (SCBs, drinking water, non-caloric diet beverages, and nutritious caloric beverages), food composition (macronutrient, water, and fiber content), and total energy intake were estimated using three 24-hour diet recalls. Beverage intake was expressed in relative terms (percentage of beverages). In fixed effects models that controlled for total beverage intake, non-caloric and nutritious caloric beverage intake (percentage of beverages), food composition, and energy expenditure [metabolic equivalent (MET)], replacing SCBs with drinking water was associated with significant decreases in total energy intake that were sustained over time. The caloric deficit attributable to replacing SCBs with water was not negated by compensatory increases in other food or beverages. Replacing all SCBs with drinking water was associated with a predicted mean decrease in total energy of 200 kcal/d over 12 months. The results suggest that replacing SCBs with drinking water can help lower total energy intake in overweight consumers of SCBs motivated to diet.

  4. Estudo do Sujamento da Superfície de Transferência de Calor do Evaporador de uma Bomba de Calor aquecido pelo efluente de uma fábrica de pasta para papel

    OpenAIRE

    Fernandes, Sofia Assunção

    2010-01-01

    O presente trabalho tem como principal objectivo a avaliação do sujamento da superfície de transferência de calor do evaporador de uma bomba de calor, quando se utiliza o efluente da fábrica de pasta e papel da Portucel Soporcel em Cacia como fluido de aquecimento. Para a realização deste estudo montou-se uma instalação, composta por uma bomba de calor, um circuito de água de arrefecimento do condensador da bomba de calor e um circuito de água residual quente para o aquecimento do evaporador ...

  5. Caloric profile of pasteurized milk in the human milk bank at a university hospital.

    Science.gov (United States)

    de Moraes, Priscila Santa; de Oliveira, Márcia Maria B; Dalmas, José Carlos

    2013-01-01

    To verify the caloric and sanitary profile of human milk stored at the Human Milk Bank at Londrina University Hospital. Cross-sectional study. Data were obtained from the Human Milk Bank registry regarding the source, the amount collected in liters, the amount of calories by liter assessed by crematocrit, and the acidity of human milk determined by titration in degrees Dornic. Between 2006 and 2009, 30,846 samples of human milk were collected from donors coming from different locations and analyzed. A total of 5,869L of milk were collected and distributed. From the total human pasteurized milk, 53,5% was classified as hypocaloric (711kcal/L). Regarding the several locations where the milk was collected, the Human Milk Bank at Londrina University Hospital was the location in which a larger number of donations were observed in the three classifications. The result of the Dornic test for acidity of the collected milk revealed that 60.8% had 4.1º to 8.0º Dornic. A large volume of the collected human milk is hypocaloric and appropriate for human consumption. There is the need to intensify collection procedures in order to meet the demand for hypercaloric milk for preterm newborn infants.

  6. Artigos esterilizados em calor úmido: validação do sistema de guarda

    Directory of Open Access Journals (Sweden)

    Zilah Cândida Pereira das Neves

    2004-04-01

    Full Text Available Objetivamos identificar o tempo de validade da esterilização dos artigos processados pelo calor úmido, considerando as condições de esterilização e guarda. A validação deu-se através de testes microbiológicos realizados com instrumentais processados numa mesma carga e avaliados em tempos 0, 7, 10, 15 e 25 dias. Foram analisados 30% do instrumental de cada pacote que foi colocado em caldo Mueller Hinton e incubado a 37ºC por 72 horas. A leitura deu-se pela turvação do caldo. Das amostras avaliadas de nove cargas, em nenhuma houve crescimento microbiológico. Concluiu-se que apesar das condições de esterilização e guarda do material não se adequarem totalmente dentro dos parâmetros recomendados pela literatura, a esterilização ocorreu e manteve-se por um período de 25 dias.

  7. Cardiovascular risk escalation with caloric excess: a prospective demonstration of the mechanics in healthy adults.

    Science.gov (United States)

    Gupta, Alok K; Johnson, William D; Johannsen, Darcy; Ravussin, Eric

    2013-01-24

    The link between weight gain and cardiovascular risk characterized with circadian blood pressure variability [CBPV] and endothelial function [EF] is unexplored. To prospectively demonstrate weight gain in healthy adults, increases body fat [BF], enlarges waist circumference [WC], expands visceral adipose tissue [VAT], exacerbates systemic inflammation [sIF], worsens insulin resistance [IR] and enhances functional cardiovascular disease [CVD] risk. Healthy men [n=11] and women [n=3] provided initial and eight-week post-caloric excess anthropometric and fasting laboratory measures. Functional CVD risk assessments: CBPV and resting EF were also obtained with 7-day automatic ambulatory BP monitoring and increased test finger peripheral arterial tone [PAT] relative to control [reported as relative hyperemia index (RHI)], respectively. After determining individualized mean energy requirements for weight maintenance over 7-days, each participant received a personalized over feeding prescription (1.4 times; 41% carbohydrate, 44% fat, and 15% protein) for 8-weeks. mean (SEM). Participants increased body weight [BW; +7.4(0.1) kg]*, body mass index [BMI; +2.5(0.2) kg/m²]*, BF [+2.0(0.01)%]*, WC [+8.2(1.0) cm]*, and VAT [+0.2(0.03) L]* and intrahepatic lipid [IHL + 0.0004(0.002) L] :*all p risk [measured as abnormal circadian blood pressure variability and impaired resting endothelial function].

  8. Liraglutide suppression of caloric intake competes with the intake-promoting effects of a palatable cafeteria diet, but does not impact food or macronutrient selection.

    Science.gov (United States)

    Hyde, Kellie M; Blonde, Ginger D; le Roux, Carel W; Spector, Alan C

    2017-08-01

    Liraglutide, a Glucagon-Like Peptide-1 (GLP-1) receptor agonist, is used as a treatment for Type 2 diabetes mellitus and obesity because it improves glycemia and decreases food intake. Here, we tested whether chronic activation of the GLP-1 receptor system with liraglutide would induce decreases in intake accompanied by changes in proportional food or macronutrient intake similar to those seen following RYGB in rats when a variety of palatable food options are available. A "cafeteria diet" was used that included: laboratory rodent chow, refried beans (low-fat/low-sugar), low-fat yogurt (low-fat/high-sugar), peanut butter (high-fat/low-sugar) and sugar-fat whip (high-fat/high-sugar). Liraglutide (1mg/kg daily, sc, n=6) induced significant reductions in body weight and total caloric intake compared to saline-injected control rats (n=6). Although access to a cafeteria diet induced increases in caloric intake in both groups relative to chow alone, liraglutide still effectively decreased intake compared with saline-injected rats suggesting that chronic GLP-1 activation competes with the energy density and palatability of available food options in modulating ingestive behavior. Even with the substantial effects on overall intake, liraglutide did not change food choice or relative macronutrient intake when compared to pre-treatment baseline. When drug treatment was discontinued, the liraglutide group increased caloric intake and rapidly gained body weight to match that of the saline group. These results demonstrate that, while liraglutide effectively decreases caloric intake and body weight in rats, it does not cause adjustments in relative macronutrient consumption. Our data also show that drug-induced decreases in intake and body weight are not maintained following termination of treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Efecto del calor aportado en recargues nanoestructurados base hierro

    Directory of Open Access Journals (Sweden)

    Agustín Gualco

    2013-12-01

    Full Text Available En los últimos años se han desarrollado consumibles de soldadura que depositan recubrimientos duros de aleaciones base hierro nanoestructuradas de gran resistencia al desgaste abrasivo. Las resistencias al desgaste erosivo y abrasivo están controladas principalmente por la composición química y la microestructura. A su vez, la microestructura del metal depositado puede presentar variaciones con el procedimiento de soldadura empleado, especialmente en relación al aporte térmico. Los parámetros operativos que definen el aporte térmico (tensión, corriente y velocidad de soldadura afectan aspectos como la geometría del cordón (ancho, penetración y sobremonta y la dilución con el material base. El propósito de este trabajo fue estudiar el efecto del calor aportado sobre las características geométricas del cordón, la dilución y la evolución microestructural de una aleación nanoestructurada base hierro, depositada por FCAW. Se soldaron muestras con aportes térmicos de entre 0,5 y 3,5 kJ/mm. Sobre cada cupón soldado se realizó un relevamiento dimensional, se analizó la composición química y se caracterizó la microestructura usando microscopías óptica y electrónica de barrido y difracción de rayos X. También se midieron la microdureza del depósito, el tamaño de cristalita y el grado de dilución. Se observó una gran influencia de las condiciones de proceso sobre la geometría del cordón. La dilución varió entre un 30 y un 40%, la microdureza del depósito se encontró entre 800 y 870 HV1 y el tamaño de cristalita osciló entre 105 y 130 nm, en función de las variables de proceso empleadas. Las mayores durezas y los menores tamaños de cristalita se obtuvieron con el menor aporte térmico, asociado a una menor dilución.

  10. The Lexicocalorimeter: Gauging public health through caloric input and output on social media.

    Directory of Open Access Journals (Sweden)

    Sharon E Alajajian

    Full Text Available We propose and develop a Lexicocalorimeter: an online, interactive instrument for measuring the "caloric content" of social media and other large-scale texts. We do so by constructing extensive yet improvable tables of food and activity related phrases, and respectively assigning them with sourced estimates of caloric intake and expenditure. We show that for Twitter, our naive measures of "caloric input", "caloric output", and the ratio of these measures are all strong correlates with health and well-being measures for the contiguous United States. Our caloric balance measure in many cases outperforms both its constituent quantities; is tunable to specific health and well-being measures such as diabetes rates; has the capability of providing a real-time signal reflecting a population's health; and has the potential to be used alongside traditional survey data in the development of public policy and collective self-awareness. Because our Lexicocalorimeter is a linear superposition of principled phrase scores, we also show we can move beyond correlations to explore what people talk about in collective detail, and assist in the understanding and explanation of how population-scale conditions vary, a capacity unavailable to black-box type methods.

  11. SirT1 regulates energy metabolism and response to caloric restriction in mice.

    Directory of Open Access Journals (Sweden)

    Gino Boily

    Full Text Available The yeast sir2 gene and its orthologues in Drosophila and C. elegans have well-established roles in lifespan determination and response to caloric restriction. We have studied mice carrying two null alleles for SirT1, the mammalian orthologue of sir2, and found that these animals inefficiently utilize ingested food. These mice are hypermetabolic, contain inefficient liver mitochondria, and have elevated rates of lipid oxidation. When challenged with a 40% reduction in caloric intake, normal mice maintained their metabolic rate and increased their physical activity while the metabolic rate of SirT1-null mice dropped and their activity did not increase. Moreover, CR did not extend lifespan of SirT1-null mice. Thus, SirT1 is an important regulator of energy metabolism and, like its orthologues from simpler eukaryotes, the SirT1 protein appears to be required for a normal response to caloric restriction.

  12. Determinación del calor de fraguado de cemento por icrocalorimetría

    Directory of Open Access Journals (Sweden)

    Liliana Girlado G.

    2010-07-01

    Full Text Available Se determina el calor de fraguado del cemento Río Claro tipo III (Río Claro, Antioquia, Colombia por microcalorimetría de conducción de calor; así como también los efectos de la glucosa y de la sacarosa en el proceso de fraguado de este material. Al emplear 0,15 y 0,05% ( % en peso de estos aditivos en la preparación de las pastas, se observan retardos considerables en el fraguado de las mismas. Los aditivos también modifican el calor de fraguado: la pasta libre de estos presenta un valor de 38,03 J/g en tanto que la adición de glucosa y sacarosa producen valores menores, excepto en el caso de la sacarosa al 0,05% donde se observa un efecto térmico de 55.80 J/s,

  13. Dietary restriction with and without caloric restriction for healthy aging [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Changhan Lee

    2016-01-01

    Full Text Available Caloric restriction is the most effective and reproducible dietary intervention known to regulate aging and increase the healthy lifespan in various model organisms, ranging from the unicellular yeast to worms, flies, rodents, and primates. However, caloric restriction, which in most cases entails a 20–40% reduction of food consumption relative to normal intake, is a severe intervention that results in both beneficial and detrimental effects. Specific types of chronic, intermittent, or periodic dietary restrictions without chronic caloric restriction have instead the potential to provide a significant healthspan increase while minimizing adverse effects. Improved periodic or targeted dietary restriction regimens that uncouple the challenge of food deprivation from the beneficial effects will allow a safe intervention feasible for a major portion of the population. Here we focus on healthspan interventions that are not chronic or do not require calorie restriction.

  14. Teoria Construtal e desempenho térmico de Trocadores de Calor Solo-Ar

    OpenAIRE

    Ruth da Silva Brum

    2016-01-01

    Trocadores de Calor Solo-Ar (TCSA) são dispositivos usados para melhorar o condicionamento térmico de ambientes construídos. Eles funcionam através da ventilação do ar por um ou mais dutos enterrados, utilizando o solo como fonte ou sumidouro de calor. Em virtude da defasagem entre as temperaturas do ar e das camadas superficiais da Terra, é possível resfriar o ar no verão e aquecê-lo no inverno. Seus princípios de operação baseiam-se na mecânica dos fluidos e transferência de calor, áreas on...

  15. Sex and race differences in caloric intake during sleep restriction in healthy adults.

    Science.gov (United States)

    Spaeth, Andrea M; Dinges, David F; Goel, Namni

    2014-08-01

    Evidence indicates that men and African Americans may be more susceptible to weight gain resulting from sleep loss than women and whites, respectively. Increased daily caloric intake is a major behavioral mechanism that underlies the relation between sleep loss and weight gain. We sought to assess sex and race differences in caloric intake, macronutrient intake, and meal timing during sleep restriction. Forty-four healthy adults aged 21-50 y (mean ± SD: 32.7 ± 8.7 y; n = 21 women, n = 16 whites) completed an in-laboratory protocol that included 2 consecutive baseline nights [10 or 12 h time in bed (TIB)/night; 2200-0800 or 2200-1000] followed by 5 consecutive sleep-restriction nights (4 h TIB/night; 0400-0800). Caloric intake and meal-timing data were collected during the 2 d after baseline sleep and the first 3 d after sleep restriction. During sleep restriction, subjects increased daily caloric intake (P sleep restriction, exhibited a greater increase in caloric intake during sleep restriction (d = 0.62), and consumed a higher percentage of daily calories during late-night hours (d = 0.78, Ps sleep restriction, or meal timing. However, African Americans consumed more carbohydrates, less protein, and more caffeine-free soda and juice than whites did during the study (Ps sleep loss than women due to a larger increase in daily caloric intake, particularly during late-night hours. These findings are relevant to the promotion of public health awareness by highlighting nutritional risk factors and modifiable behaviors for weight gain related to sleep-wake timing. © 2014 American Society for Nutrition.

  16. Moderate exercise training and chronic caloric restriction modulate redox status in rat hippocampus.

    Science.gov (United States)

    Santin, Katiane; da Rocha, Ricardo Fagundes; Cechetti, Fernanda; Quincozes-Santos, André; de Souza, Daniela Fraga; Nardin, Patrícia; Rodrigues, Letícia; Leite, Marina Concli; Moreira, José Cláudio Fonseca; Salbego, Christianne Gazzana; Gonçalves, Carlos Alberto

    2011-11-03

    Physical activity has been related to antioxidant adaptations, which is associated with health benefits, including those to the nervous system. Additionally, available data suggest exercise and a caloric restriction regimen may reduce both the incidence and severity of neurological disorders. Therefore, our aim was to compare hippocampal redox status and glial parameters among sedentary, trained, caloric-restricted sedentary and caloric-restricted trained rats. Forty male adult rats were divided into 4 groups: ad libitum-fed sedentary (AS), ad libitum-fed exercise training (AE), calorie-restricted sedentary (RS) and calorie-restricted exercise training (RE). The caloric restriction (decrease of 30% in food intake) and exercise training (moderate in a treadmill) were carried out for 3 months. Thereafter hippocampus was surgically removed, and then redox and glial parameters were assessed. Increases in reduced glutathione (GSH) levels and total antioxidant reactivity (TAR) were observed in AE, RS and RE. The nitrite/nitrate levels decreased only in RE. We found a decrease in carbonyl content in AE, RS and RE, while no modifications were detected in thiobarbituric acid reactive substances (TBARS). Total reactive antioxidant potential (TRAP), superoxide dismutase (SOD) activity, S100B and glial fibrilary acid protein (GFAP) content did not change, but caloric restriction was able to increase glutamine synthetase (GS) activity in RS and glutamate uptake in RS and RE. Exercise training, caloric restriction and both combined can decrease oxidative damage in the hippocampus, possibly involving modulation of astroglial function, and could be used as a strategy for the prevention of neurodegenerative diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. High-throughput search for caloric materials: the CaloriCool approach

    Science.gov (United States)

    Zarkevich, N. A.; Johnson, D. D.; Pecharsky, V. K.

    2018-01-01

    The high-throughput search paradigm adopted by the newly established caloric materials consortium—CaloriCool®—with the goal to substantially accelerate discovery and design of novel caloric materials is briefly discussed. We begin with describing material selection criteria based on known properties, which are then followed by heuristic fast estimates, ab initio calculations, all of which has been implemented in a set of automated computational tools and measurements. We also demonstrate how theoretical and computational methods serve as a guide for experimental efforts by considering a representative example from the field of magnetocaloric materials.

  18. Effect of consuming different caloric sweeteners on bone health and possible mechanisms.

    Science.gov (United States)

    Tsanzi, Embedzayi; Fitch, Cindy W; Tou, Janet C

    2008-06-01

    Western diets are high in caloric sweeteners and since the 1980s there has been a shift from the use of sucrose as the predominant sweetener to high-fructose corn syrup. This may have important implications for bone, as sugar consumption has been shown to negatively impact mineral balance. This article reviews the existing scientific evidence regarding the effect of caloric sweeteners and the type of sweetener on bone health and the potential mechanisms of action. A better understanding of the role of sugar consumption on mineral balance and bone can contribute to the determination of dietary recommendations to reduce bone loss and the future risk of osteoporosis.

  19. Análisis estructural de un intercambiador de calor de un reactor avanzado

    OpenAIRE

    García Merino, Carlos

    2008-01-01

    El objetivo fundamental de este proyecto consiste en el estudio estructural de un intercambiador de calor de un reactor avanzado de Generación VI. Este intercambiador de calor es el condensador PCCS (Passive Containment Cooling System), sistema de seguridad de una central nuclear ESBWR. El análisis estructural del condensador se ha realizado analítica y numéricamente. El cálculo analítico utiliza expresiones obtenidas del código ASME, para determinar tensiones por presiones internas. Y el cál...

  20. Isotermas e calor isostérico de sementes de Buchenavia capitata (Vahl) Eichler

    OpenAIRE

    Costa,Lílian Moreira; Resende,Osvaldo; Oliveira,Daniel Emanuel Cabral de; Sousa,Kelly Aparecida de

    2015-01-01

    RESUMODiante da importância do conhecimento da higroscopicidade e do calor isostérico para as operações de secagem e armazenamento, objetivou-se neste trabalho determinar as isotermas de dessorção de sementes de Buchenavia capitata (Vahl) Eichler, bem como ajustar diferentes modelos matemáticos aos dados experimentais, selecionando aquele que melhor representa o fenômeno e, assim, utilizá-lo para determinar o calor isostérico de dessorção. Para obtenção do teor de água de equilíbrio higroscóp...

  1. Effects of Experimental Sleep Restriction on Weight Gain, Caloric Intake, and Meal Timing in Healthy Adults.

    Science.gov (United States)

    Spaeth, Andrea M; Dinges, David F; Goel, Namni

    2013-07-01

    Examine sleep restriction's effects on weight gain, daily caloric intake, and meal timing. Repeated-measures experiments assessing body weight at admittance and discharge in all subjects (N = 225) and caloric intake and meal timing across days following 2 baseline nights, 5 sleep restriction nights and 2 recovery nights or across days following control condition nights in a subset of subjects (n = 37). Controlled laboratory environment. Two hundred twenty-five healthy adults aged 22-50 y (n = 198 sleep-restricted subjects; n = 31 with caloric intake data; n = 27 control subjects; n = 6 with caloric intake data). Approximately 8-to-1 randomization to an experimental condition (including five consecutive nights of 4 h time in bed [TIB]/night, 04:00-08:00) or to a control condition (all nights 10 h TIB/night, 22:00-08:00). Sleep-restricted subjects gained more weight (0.97 ± 1.4 kg) than control subjects (0.11 ± 1.9 kg; d = 0.51, P = 0.007). Among sleep-restricted subjects, African Americans gained more weight than Caucasians (d = 0.37, P = 0.003) and males gained more weight than females (d = 0.38, P = 0.004). Sleep-restricted subjects consumed extra calories (130.0 ± 43.0% of daily caloric requirement) during days with a delayed bedtime (04:00) compared with control subjects who did not consume extra calories (100.6 ± 11.4%; d = 0.94, P = 0.003) during corresponding days. In sleep-restricted subjects, increased daily caloric intake was due to more meals and the consumption of 552.9 ± 265.8 additional calories between 22:00-03:59. The percentage of calories derived from fat was greater during late-night hours (22:00-03:59, 33.0 ± 0.08%) compared to daytime (08:00-14:59, 28.2 ± 0.05%) and evening hours (15:00-21:59, 29.4 ± 0.06%; Ps sleep restriction promoted weight gain. Chronically sleep-restricted adults with late bedtimes may be more susceptible to weight gain due to greater daily caloric intake and the consumption of calories during late-night hours

  2. Normal physical activity obliterates the deleterious effects of high-caloric intake

    DEFF Research Database (Denmark)

    Krogh-Madsen, Rikke; Pedersen, Maria; Solomon, Thomas

    2013-01-01

    A high-caloric intake combined with a sedentary lifestyle is an important player in the development of type 2 diabetes mellitus (T2DM). The present study was undertaken to examine if the level of physical activity has impact on the metabolic effects of a high-caloric (+2,000 kcal/day) intake...... function with regard to capacity of attention. In conclusion, we find evidence to support that habitual physical activity may prevent pathophysiological symptoms associated with diet-induced obesity....

  3. Effect of the osmolality of caloric and acaloric liquids on gastric myoelectrical activity in humans.

    Science.gov (United States)

    Syrkiewicz-Trepiak, Danuta; Jonderko, Krzysztof; Kasicka-Jonderko, Anna

    2010-05-01

    The aim was to establish the effect of the osmolality of orally consumed liquids on gastric myoelectrical activity (GMA). Twenty-five healthy volunteers (13 women, 12 men aged 29.4+/-1.4 [SE] years) underwent five examinations on separate days. After a 20-min basal electrogastrographic recording, the volunteers drank 400 ml of a) bi-distilled water, b) 0.9% NaCl, osmolality 286 mmol/kg, c) 2.9% NaCl, osmolality 827 mmol/kg, d) 5% glucose, osmolality 282 mmol/kg, energy density 209 kcal/l, or e) 15% glucose, osmolality 836 mmol/kg, 627 kcal/l. Then the registration of GMA was continued for 60 min. Gastric emptying was measured with the 13C-acetate breath test. Compared with distilled water, the isotonic glucose drink elicited a positive chronotropic influence on and stabilization of GMA. At the transition from isotonicity to hypertonicity, a pronounced destabilization of GMA was observed, with opposite directions of changes brought about by the presence or absence of a caloric load; bradygastria was manifested after the energy-free hypertonic NaCl solution whereas hypertonic glucose evoked a tachygastric pattern. A marked delay in gastric emptying was found with both hypertonic drinks. Osmolality and its interplay with chemical composition/energy density must be taken into account when choosing a test meal for an electrogastrographic examination and interpreting its results. Of the five fluids examined, isotonic glucose appeared to be the drink least disturbing to GMA.

  4. Weight gain in mice on a high caloric diet and chronically treated with omeprazole depends on sex and genetic background.

    Science.gov (United States)

    Saqui-Salces, Milena; Tsao, Amy C; Gillilland, Merritt G; Merchant, Juanita L

    2017-01-01

    The impact of omeprazole (OM), a widely used over-the-counter proton pump inhibitor, on weight gain has not been extensively explored. We examined what factors, e.g., diet composition, microbiota, genetic strain, and sex, might affect weight gain in mice fed a high caloric diet while on OM. Inbred C57BL/6J strain, a 50:50 hybrid (B6SJLF1/J) strain, and mice on a highly mixed genetic background were fed four diets: standard chow (STD, 6% fat), STD with 200 ppm OM (STD + O), a high-energy chow (HiE, 11% fat), and HiE chow with OM (HiE + O) for 17 wk. Metabolic analysis, body composition, and fecal microbiota composition were analyzed in C57BL/6J mice. Oral glucose tolerance tests were performed using mice on the mixed background. After 8 wk, female and male C57BL/6J mice on the HiE diets ate less, whereas males on the HiE diets compared with the STD diets gained weight. All diet treatments reduced energy expenditure in females but in males only those on the HiE + O diet. Gut microbiota composition differed in the C57BL/6J females but not the males. Hybrid B6SJLF1/J mice showed similar weight gain on all test diets. In contrast, mixed strain male mice fed a HiE + O diet gained ∼40% more weight than females on the same diet. In addition to increased weight gain, mixed genetic mice on the HiE + O diet cleared glucose normally but secreted more insulin. We concluded that sex and genetic background define weight gain and metabolic responses of mice on high caloric diets and OM. Copyright © 2017 the American Physiological Society.

  5. Effect of Replacing Sugar with Non-Caloric Sweeteners in Beverages on the Reward Value after Repeated Exposure

    NARCIS (Netherlands)

    Griffioen-Roose, S.; Smeets, P.A.M.; Weijzen, P.L.G.; Rijn, van I.; Bosch, van den I.; Graaf, de C.

    2013-01-01

    Background: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. Objective: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty

  6. False-Positive Head-Impulse Test in Cerebellar Ataxia

    Science.gov (United States)

    Kremmyda, Olympia; Kirchner, Hanni; Glasauer, Stefan; Brandt, Thomas; Jahn, Klaus; Strupp, Michael

    2012-01-01

    The objective of this study was to compare the findings of the bedside head-impulse test (HIT), passive head rotation gain, and caloric irrigation in patients with cerebellar ataxia (CA). In 16 patients with CA and bilaterally pathological bedside HIT, vestibuloocular reflex (VOR) gains were measured during HIT and passive head rotation by scleral search coil technique. Eight of the patients had pathologically reduced caloric responsiveness, while the other eight had normal caloric responses. Those with normal calorics showed a slightly reduced HIT gain (mean ± SD: 0.73 ± 0.15). In those with pathological calorics, gains 80 and 100 ms after the HIT as well as the passive rotation VOR gains were significantly lower. The corrective saccade after head turn occurred earlier in patients with pathological calorics (111 ± 62 ms after onset of the HIT) than in those with normal calorics (191 ± 17 ms, p = 0.0064). We identified two groups of patients with CA: those with an isolated moderate HIT deficit only, probably due to floccular dysfunction, and those with combined HIT, passive rotation, and caloric deficit, probably due to a peripheral vestibular deficit. From a clinical point of view, these results show that the bedside HIT alone can be false-positive for establishing a diagnosis of a bilateral peripheral vestibular deficit in patients with CA. PMID:23162531

  7. Influência do calor armazenado no sistema solo-planta no balanço de energia em pomar de mangueiras Influence of the heat stored in the soil-plant system in the energy balance over a mango orchard

    Directory of Open Access Journals (Sweden)

    Cícera J. R. Borges

    2008-08-01

    Full Text Available Neste estudo se objetivou a avaliação da contribuição do calor armazenado acima das placas de fluxo de calor no solo e no dossel vegetativo sobre os componentes do balanço de energia, no pomar de mangueiras. Os componentes do balanço de energia foram obtidos pelo método do balanço de energia com base na razão de Bowen. O teste t-Student foi usado para avaliar a existência de diferença significativa entre as médias dos componentes do balanço de energia, obtidas mediante as seguintes condições: (i considerando-se o calor armazenado acima dos fluxímetros e (ii desconsiderando-se o calor armazenado acima dos fluxímetros, cujos resultados indicaram que: 1 o efeito do calor armazenado no dossel vegetativo é irrelevante quando comparado com os outros componentes do balanço de energia em pomar de mangueiras; 2 o calor armazenado acima das placas de calor no solo não interfere significativamente no cálculo dos fluxos de calor sensível e latente nem na evapotranspiração da mangueira irrigada; 3 o fluxo de calor no solo, corrigido com o calor armazenado acima dos fluxímetros, difere estatisticamente a nível de 5% de probabilidade, daquele obtido sem a correção do fluxo.The objective of this study was to investigate the contribution of the heat storage above the soil heat flux plates and within the canopy upon the components of the energy balance in the mango orchard. The Bowen energy-ratio balance method was used for obtaining the energy balance components and evapotranspiration of the mango orchard. The t-Student test was applied to evaluate statistical significance of the difference between energy balance component averages under the following conditions: (i considering and (ii not considering the heat storage above the fluximeters. The results suggested that: 1 the canopy heat storage is irrelevant compared to the other energy balance components; 2 the above soil heat plates heat storage does not influence the sensible and

  8. Fluxo de calor sensível em cultivo de feijão-caupi Sensible heat flux in cowpea

    Directory of Open Access Journals (Sweden)

    José R. de S Lima

    2011-10-01

    Full Text Available O presente trabalho objetivou comparar o fluxo de calor sensível obtido pelo método do balanço de energia-razão de Bowen (H_B e pelo método aerodinâmico (H_A, em uma área de 4 ha cultivada com feijão-caupi em Areia-PB (6º 58' 12" S e 35º 42' 15" O, 620 m. Foram coletados dados de saldo de radiação, fluxo de calor no solo, temperatura e umidade do solo, temperatura e umidade relativa do ar, velocidade do vento e precipitação pluvial, os quais eram lidos a cada minuto, e armazenados, em uma central de aquisição de dados, como médias a cada 30 min, com exceção da pluviometria, cujo valor foi totalizado no período. Obteve-se excelente concordância entre H_A e H_B, com um índice "d " de 0,980, um erro padrão (EP de 14,88 W m-2, e sem diferença significativa entre H_A e H_B, pelo teste t-Student. Deste modo, o método aerodinâmico pode ser usado em conjunto com medidas de saldo de radiação e de fluxo de calor no solo, para se estimar o fluxo de calor latente e, consequentemente, a evapotranspiração da cultura do feijão-caupi, para as condições edafoclimáticas do Brejo Paraibano.A study was performed to compare the bulk aerodynamic (H_A and Bowen ratio energy balance (H_B methods in the estimation of the sensible heat flux in a cowpea crop. Data of net radiation, soil heat flux, soil water content, soil temperature, air temperature, relative humidity, wind speed and rainfall were collected on 30-min time intervals in an area of 4 ha belonging to the municipality of Areia, PB (6º 58' 12" S e 35º 42' 15" W, 620 m. Results showed that there was a good agreement between H_A and H_B with an index "d" of 0.98 and standard error of estimate (SEE of 14.88 W m-2, no significant difference between H_A H_B, by the t-Student test. Thus, the bulk aerodynamic method can be used in conjunction with measurements of net radiation and soil heat flux to estimate the evapotranspiration of the cowpea under soil and climatic condition of

  9. Thermoregulatory, Cardiovascular, and Metabolic Responses to Mild Caloric Restriction in the Brown Norway Rat

    Science.gov (United States)

    Caloric restriction (CR) has been demonstrated to prolong the life span of a variety of species. CR-induced reduction in core temperature (Tc) is considered a key mechanism responsible for prolonging life span in rodents; however, little is known on the regulation of CR-induced h...

  10. Biochemical composition and caloric potential of zooplankton from Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sreepada, R.A.; Rivonker, C.U.; Parulekar, A.H.

    .62, 4.95, 1.54, 0.43, 4.4 and 4.16 respectively on wet weight basis. A good correlation of caloric potential with protein and lipid indicated to a certain extent that protein and lipid act as metabolic reserves of the zooplankton in the area...

  11. Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

    Directory of Open Access Journals (Sweden)

    Ken Shinmura

    2013-01-01

    Full Text Available The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

  12. Caloric variability of Corbicula fluminea (Mollusca, Bivalvia in Rosana Reservoir, Brazil

    Directory of Open Access Journals (Sweden)

    Yara Moretto Bagatini

    2007-01-01

    Full Text Available The purpose of the present study was to investigate temporal and longitudinal variation of caloric density of Corbicula fluminea in Rosana Reservoir. Significant differences concerning the caloric density of C. fluminea were observed throughout the year at the three reservoir sites. The caloric density variation during the year was probably related to reproductive activity, which demanded higher allocation of energy in certain period. The food source used by this species might be an important factor in the caloric value temporal and spatial variation of C. fluminea in Rosana Reservoir.O objetivo deste estudo foi investigar a variação temporal e longitudinal da densidade calórica de C. fluminea no reservatório de Rosana. Diferenças significativas na densidade calórica de C. fluminea foram observadas ao longo do ano e nas três estações do reservatório. A variação na densidade calórica de C. fluminea, durante o ano, provavelmente foi relacionada à atividade reprodutiva, que exige uma maior alocação de energia em determinado período. O recurso alimentar utilizado por esta espécie pode ser um importante fator na variação temporal e espacial do valor calórico de C. fluminea no reservatório de Rosana.

  13. Benefits of caloric restriction in the myenteric neuronal plasticity in aging rats

    Directory of Open Access Journals (Sweden)

    JOICE N.B. PEREIRA

    2014-09-01

    Full Text Available Aging is a biologic process characterized by progressive damage of structures and functions of organic systems. In gastrointestinal tract, it can involve enteric nervous system, which plays an important role in digestion and absorption of nutrients, causing hastening of intestinal transit thus reducing its absorptive function. Caloric restriction has been used in several studies with the intention of delaying deleterious effects of aging. This study aimed to evaluate the effects of caloric restriction on myenteric neurons of ileum by aging in rats. 30 Wistar rats were grouped as follows: GI (animals aged 6 months fed with normal diet, GII (animals aged 18 months fed with normal diet and GIII (animals aged 18 months subject to 31% of caloric restriction. The rats of the GI group were euthanized at 6 months of age and after experimental period of 12 months animals of the group GII and GIII were euthanized, the ileum of all groups were collected, measured and processed by NADPH-dp and Acetylcholinesterase. Quantitative analysis of neurons revealed that aging promotes the increasing of myenteric neurons NADPH-dp and reduces Acetylcholinesterase neuronal population. However, in the cellular profile area, were not observed significant differences between the groups. The caloric restriction has been efficient and can be used preventively because it minimizes quantitative changes associated with aging on ileum myenteric plexuses.

  14. Benefits of caloric restriction in the myenteric neuronal plasticity in aging rats.

    Science.gov (United States)

    Pereira, Joice N B; Mari, Renata B; Stabille, Sandra R; de Faria, Haroldo G; Mota, Thais F M; Ferreira, Walter M

    2014-09-01

    Aging is a biologic process characterized by progressive damage of structures and functions of organic systems. In gastrointestinal tract, it can involve enteric nervous system, which plays an important role in digestion and absorption of nutrients, causing hastening of intestinal transit thus reducing its absorptive function. Caloric restriction has been used in several studies with the intention of delaying deleterious effects of aging. This study aimed to evaluate the effects of caloric restriction on myenteric neurons of ileum by aging in rats. 30 Wistar rats were grouped as follows: GI (animals aged 6 months fed with normal diet), GII (animals aged 18 months fed with normal diet) and GIII (animals aged 18 months subject to 31% of caloric restriction). The rats of the GI group were euthanized at 6 months of age and after experimental period of 12 months animals of the group GII and GIII were euthanized, the ileum of all groups were collected, measured and processed by NADPH-dp and Acetylcholinesterase. Quantitative analysis of neurons revealed that aging promotes the increasing of myenteric neurons NADPH-dp and reduces Acetylcholinesterase neuronal population. However, in the cellular profile area, were not observed significant differences between the groups. The caloric restriction has been efficient and can be used preventively because it minimizes quantitative changes associated with aging on ileum myenteric plexuses.

  15. Curcumin Mimics the Neurocognitive and Anti-Inflammatory Effects of Caloric Restriction in a Mouse Model of Midlife Obesity.

    Directory of Open Access Journals (Sweden)

    Marjana Rahman Sarker

    Full Text Available Dietary curcumin was studied for its potential to decrease adiposity and reverse obesity- associated cognitive impairment in a mouse model of midlife sedentary obesity. We hypothesized that curcumin intake, by decreasing adiposity, would improve cognitive function in a manner comparable to caloric restriction (CR, a weight loss regimen. 15-month-old male C57BL/6 mice were assigned in groups to receive the following dietary regimens for 12 weeks: (i a base diet (Ain93M fed ad libitum (AL, (ii the base diet restricted to 70% of ad libitum (CR or (iii the base diet containing curcumin fed AL (1000 mg/kg diet, CURAL. Blood markers of inflammation, interleukin 6 (IL-6 and C-reactive protein (CRP, as well as an indicator of redox stress (GSH: GSSG ratio, were determined at different time points during the treatments, and visceral and subcutaneous adipose tissue were measured upon completion of the experiment. After 8 weeks of dietary treatment, the mice were tested for spatial cognition (Morris water maze and cognitive flexibility (discriminated active avoidance. The CR group showed significant weight loss and reduced adiposity, whereas CURAL mice had stable weight throughout the experiment, consumed more food than the AL group, with no reduction of adiposity. However, both CR and CURAL groups took fewer trials than AL to reach criterion during the reversal sessions of the active avoidance task, suggesting an improvement in cognitive flexibility. The AL mice had higher levels of CRP compared to CURAL and CR, and GSH as well as the GSH: GSSG ratio were increased during curcumin intake, suggesting a reducing shift in the redox state. The results suggest that, independent of their effects on adiposity; dietary curcumin and caloric restriction have positive effects on frontal cortical functions that could be linked to anti-inflammatory or antioxidant actions.

  16. Feed restriction and a diet's caloric value: The influence on the aerobic and anaerobic capacity of rats

    Directory of Open Access Journals (Sweden)

    de Moura Leandro

    2012-03-01

    Full Text Available Abstract Background The influence of feed restriction and different diet's caloric value on the aerobic and anaerobic capacity is unclear in the literature. Thus, the objectives of this study were to determine the possible influences of two diets with different caloric values and the influence of feed restriction on the aerobic (anaerobic threshold: AT and anaerobic (time to exhaustion: Tlim variables measured by a lactate minimum test (LM in rats. Methods We used 40 adult Wistar rats. The animals were divided into four groups: ad libitum commercial Purina® diet (3028.0 Kcal/kg (ALP, restricted commercial Purina® diet (RAP, ad libitum semi-purified AIN-93 diet (3802.7 Kcal/kg (ALD and restricted semi-purified AIN-93 diet (RAD. The animals performed LM at the end of the experiment, 48 h before euthanasia. Comparisons between groups were performed by analysis of variance (p Results At the end of the experiment, the weights of the rats in the groups with the restricted diets were significantly lower than those in the groups with ad libitum diet intakes. In addition, the ALD group had higher amounts of adipose tissue. With respect to energetic substrates, the groups subjected to diet restriction had significantly higher levels of liver and muscle glycogen. There were no differences between the groups with respect to AT; however, the ALD group had lower lactatemia at the AT intensity and higher Tlim than the other groups. Conclusions We conclude that dietary restriction induces changes in energetic substrates and that ad libitum intake of a semi-purified AIN-93 diet results in an increase in adipose tissue, likely reducing the density of the animals in water and favouring their performance during the swimming exercises.

  17. The comparative effect of fasting with and without caloric restriction in Rat on oxidative stress parameters

    Directory of Open Access Journals (Sweden)

    Nurina Tyagita

    2016-09-01

    Full Text Available Introduction: Fasting, like Islamic Ramadan Fasting, has been associated with health benefits. Islamic Ramadan fasting, a form of caloric restriction (CR or alternate day fasting that. Studies suggest a comparable effect of ADF and caloric restriction. Despite the fact that fasting can be considered as a form of dietary restriction, fasters tend to have difficulty to reduce their food intake during non-fasting period by overeating leading to the excessive calorie intake. To compare the effect of fasting with and without caloric restriction in Sprague Dawley rats. Methods: The rats were assigned to one of three groups: ADF with 70 % calorie intake (30% CR, ADF with 100 % calorie intake (0% CR, and ADF with 140 % calorie intake (excessive calorie intake and AL (fed ad libitum. All groups were subjected to 6 hour fasting per day (9 a.m. until 3 p.m. or 15 days. The plasma sample was taken for MDA level assessment. Urinary 8-oxodG levels were determined by using ELISA. Results: ADF with 30% calorie restriction (F70 group had the lowest MDA level. Measurement of 8-oxodG level showed that group F70 had the highest production of 8-oxodG. There was an inverse relationship between MDA level and 8-oxodG level meaning the lower MDA level, the lower 8-oxodG levels were produced. Conclusion: ADF fasting with 30% caloric restriction reduce the MDA level but increase 8-oxodG levels. This study suggest the beneficial effect of fasting requires decrease in overall caloric intake.

  18. Automobilismo: no calor da competição Automovilismo: en el calor de la competición Car racing: in the heat of competition

    Directory of Open Access Journals (Sweden)

    Luiz Oswaldo Carneiro Rodrigues

    2004-06-01

    Full Text Available O presente artigo questiona o papel do calor como um fator de risco adicional para o acidente que vitimou Ayrton Senna. O automobilismo de competição constitui um desafio biológico, uma situação estressante do ponto de vista mental e físico. A manutenção da performance depende da disponibilidade de carboidratos e oxigênio, hidratação adequada e temperatura interna constante entre 37 e 38 graus centígrados. A dissipação do calor produzido pelo metabolismo ocorre através do aumento do fluxo de sangue para pele e produção de suor e manter a temperatura cerebral constante se constitui num problema permanente. Verificou-se experimentalmente que a energia necessária para dirigir um automóvel de corrida é comparável a um esporte como o voleibol. Durante uma corrida, o indivíduo está exposto a um microambiente quente na cabina, que pode atingir 50ºC, gerado por fontes de calor mecânicas e ambientais. O bloqueio da evaporação do suor pelo macacão resulta em umidade e desconforto pessoal, o que implica maior esforço mental para dirigir o carro. As medidas contra o calor começam antes da corrida, cuidando-se do estado nutricional, da hidratação e principalmente do condicionamento físico através de exercícios aeróbios regulares e adequados, que permitem aumentar a capacidade de trabalho e a tolerância ao calor, o que resulta em menor fadiga durante a corrida. Outro procedimento importante deveria ser a aclimatação prévia dos pilotos aos ambientes quentes e úmidos. Deve-se fazer o possível para reduzir o aquecimento do veículo e respeitar o sistema de bandeiras de advertência para os riscos de hipertermia. Em conclusão, embora Ayrton Senna fosse um indivíduo com maior risco de desenvolver hipertermia, independentemente de outras causas, não parece ter havido tempo de corrida suficiente para haver produção de calor metabólico capaz de aumentar excessivamente a temperatura interna do piloto nas condi

  19. Coeficientes de transferencia de calor y pérdida de eficiencia en intercambiadores de calor de placas durante el enfriamiento del licor amoniacal

    Directory of Open Access Journals (Sweden)

    Enrique Torres-Tamayo

    2011-10-01

    Full Text Available En la planta de Recuperación de Amoniaco de la empresa niquelera Ernesto Che Guevara la pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, se asocia a la incorrecta estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio; lo anterior incrementa el consumo de agua, la energía disponible en el sistema y los costos de mantenimiento. Se realizó una investigación en un intercambiador de calor de placas, con el objetivo de determinar los coeficientes de transferencia y la influencia de las incrustaciones en la pérdida de eficiencia de la instalación. Mediante un procedimiento iterativo se determinó la ecuación del número de Nusselt y su dependencia con el Reynolds y Prandtl, para ello se utilizó un diseño experimental multifactorial y mediciones de los parámetros de trabajo de la instalación en función del tiempo. Los resultados predicen el conocimiento de los coeficientes para el cálculo del número de Nusselt, con los valores de Reynolds y Prandtl, para ambos fluidos (licor amoniacal y agua. Los valores de los coeficientes del licor son inferiores, ello se debe a la presencia de componentes gaseosos. La comparación con resultados de otros autores muestra correspondencia con los de Thonon. Se recomienda la limpieza y mantenimiento de la instalación en un período de 27 días debido a la reducción de la eficiencia térmica hasta valores inferiores al 70 %.

  20. Estudio y optimización de los sistemas de intercambio de calor en generación termoeléctrica aplicada al aprovechamiento del calor residual

    OpenAIRE

    Aranguren Garacochea, Patricia

    2015-01-01

    La presente tesis doctoral estudia el aprovechamiento del calor residual mediante generación termoeléctrica para la obtención de potencia eléctrica generada gracias al efecto Seebeck. Dos son las aproximaciones empleadas, la simulación computacional, empleando variables obtenidas experimentalmente y la experimentación de escenarios reales. Ambas dos han obtenido valores muy prometedores para la generación eléctrica a través de los gases residuales. Con el desarrollo de esta tesis doctoral,...

  1. Prácticas de Física: Equivalente en agua de un calorímetro

    OpenAIRE

    Beléndez,Augusto; Bernabeu, Guillermo; Vera Guarinos, Jenaro; Pastor Antón, Carlos; Martín García, Agapito

    1988-01-01

    Esta práctica de laboratorio tiene como objetivo el cálculo del equivalente en agua de un calorímetro con su error, familiarizarse con el uso del mismo y del termómetro. Para el desarrollo de esta práctica se dispone de un calorímetro lleno de agua en el que se ha colocado una resistencia interna. Se hace circular una corriente por la resistencia, de manera que la potencia que disipa la resistencia se convierte en potencia calorífica, por efecto Joule, calentando por un lado el agua en el int...

  2. Incremento de la productividad por recuperación de calor en gases de chimenea de un horno de cubilote

    OpenAIRE

    Mejía Arango, Héctor Daniel; Silva, Claudia; Aristizábal Sierra, Ricardo Emilio

    2003-01-01

    Sobre la base de la primera ley de la termodinámica se realiza el balance de calor para dos cubilotes típicos y para el cubilote de la Universidad de Antioquia, en este último, antes y después de ser instalado y puesto a punto el sistema de recuperación de calor, que opera con dos regeneradores de lecho empacado. Con los resultados obtenidos en el prototipo eco-eficiente se demuestran las ventajas de trabajar un cubilote con sistemas que recuperen calor de los gases de chimenea, resaltando en...

  3. Is the caloric curve a robust signal of the phase transition in hot nuclei?

    Science.gov (United States)

    Vient, E.

    2017-11-01

    The richness of the data set, collected by the INDRA Collaboration during the last twenty years, enabled us to build a set of caloric curves for nuclei of various sizes, by using, for the first time, a single experimental set-up and a single experimental protocol. We will therefore present the different caloric curves ( E^{\\ast}-T obtained by a new calorimetry, for Quasi-Projectiles produced by symmetric or quasi symmetric reactions at different incident energies (Au + Au, Xe + Sn, Ni + Ni). For all these systems, a clear change of the de-excitation process of hot nuclei is observed but this one is neither a plateau nor a back-bending, but a sudden change of slope.

  4. Transferência de calor no escoamento turbulento em desenvolvimento entre placas planas paralelas

    OpenAIRE

    Marcio Bueno dos Santos

    1991-01-01

    O presente trabalho tem por finalidade a análise experimental do problema de convecção forçada entre placas paralelas no escoamento com transição laminar-turbulento, com condições assimétricas do perfil de temperatura. A determinação dos valores locais dos coeficientes de transferência de calor é obtida aplicando-se a técnica se Sublimação de Naftaleno. De acordo com a analogia entre transferência de calor e transferência de massa as condições experimentais correspondem a situação de transfer...

  5. Caloric Intake From Fast Food Among Children and Adolescents in the United States, 2011-2012.

    Science.gov (United States)

    Vikraman, Sundeep; Fryar, Cheryl D; Ogden, Cynthia L

    2015-09-01

    Consumption of fast food has been linked to weight gain in adults (1). Fast food has also been associated with higher caloric intake and poorer diet quality in children and adolescents (2). From 1994 through 2006, caloric intake from fast food increased from 10% to 13% among children aged 2-18 years (3). This report presents the most recent data on the percentage of calories consumed from fast food among U.S. children by sex, age group, race and Hispanic origin, poverty status, and weight status. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

  6. Current and future employment of the heat pumps; Pompe di calore. Presente e futuro

    Energy Technology Data Exchange (ETDEWEB)

    Cassitto, L. [Milan Politecnico, Milan (Italy). Dipt. di Energetica

    2001-12-01

    Heat pumps, mainly the compression type, grant high energy savings together with environment protection because of the free low temperature energy from environment or wasted heat they use. Their large employment depends on the appreciation of the above properties that are will be done. To grant economic savings on using heat pumps, electric energy and natural gas should have fixed and predictable prices. [Italian] Le pompe di calore, in particolare quelle a compressione, hanno elevate prestazioni energetiche e ambientali, grazie all'utilizzo di fonti di calore gratuite a bassa temperatura, naturali o residue di altri processi. La loro diffusione e' legata alla percezione di queste potenzialita' rinunciando alle caldaie tradizionali. Sono indispensabili prezzi dell'energia elettrica e del metano stabili e comunque prevedibili per garantire anche la loro convenienza economica.

  7. Developmental toxicity study in rats and rabbits administered an emulsion containing medium chain triglycerides as an alternative caloric source.

    Science.gov (United States)

    Henwood, S; Wilson, D; White, R; Trimbo, S

    1997-12-01

    Triglyceride-containing lipid emulsions have been designed as caloric sources that can be administered intravenously to patients that cannot meet their nutritional needs by conventional parenteral therapies. In their study, we evaluate the developmental toxicity of a 20% lipid emulsion that contains a 3:1 ratio of medium chain triglyceride (MCT) to one long chain containing lipid emulsion (LCT). This emulsion was administered by intravenous infusion to rats and rabbits at dosages of 1 and 4.28 g lipid/kg body weight (g lipid/kg) at dose volumes of 5 and 21.4 mL/kg, respectively, once daily during organogenesis to assess the potential developmental toxicity of the test article. The control group received 0.9% saline at a dose volume of 21.4 mL/kg. Animals were observed for clinical signs of toxicity and adverse effects on body weights and feed consumption. On Day 20 (rats) or Day 29 (rabbits), females were necropsied and examined for maternal and embryo/fetal toxicity. Fetuses were removed, weighed, and examined for external, soft tissue, and skeletal abnormalities. Dosages of 4.28 g lipid/kg resulted in lower feed consumption for rats and rabbits, an expected finding based on the high-caloric nature of the test article. Potentially test article-related gross necropsy findings, including enlarged lymph nodes and spleen, small thymus, and enlarged renal pelvis, for rats given 4.28 g lipid/kg were present at a low incidence. There were no adverse effects on fetal parameters for rats even in the presence of some maternal toxicity. However, embryo and fetal toxicity (i.e., resorptions) and skeletal abnormalities were present for rabbits given 4.28 g lipid/kg. Under the conditions of this study, the no-observable-effect level for developmental toxicity was greater than or equal to 4.28 g lipid/kg for rats and greater than or equal to 1 g lipid/kg but less than 4.28 g lipid/kg for rabbits.

  8. Caloric restriction in lean and obese strains of laboratory rat: effects on body composition, metabolism, growth and overall health

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data related to obese and lean strains of rat commonly used in the laboratory that are calorically restricted and its effects on physiologic parameters (Body...

  9. Effects of Moderate Aerobic Exercise Combined With Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy I

    2004-01-01

    ... the primary prevention of breast cancer in women. This study has examined the effects of exercise training combined with caloric restriction, resulting in weight loss, on two hormonal biomarkers for breast cancer i.e...

  10. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study

    National Research Council Canada - National Science Library

    Spitoni, Grazia Fernanda; Pireddu, Giorgio; Galati, Gaspare; Sulpizio, Valentina; Paolucci, Stefano; Pizzamiglio, Luigi

    2016-01-01

    .... To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain...

  11. Análise da transferência de calor em paredes compostas por diferentes materiais

    Directory of Open Access Journals (Sweden)

    Luciano Pivoto Specht

    Full Text Available O projeto de edificações energeticamente eficientes necessita de conhecimentos sobre a transferência de calor proveniente do ambiente externo, a fim de criar soluções que associem diferentes materiais e espessuras às condições desejadas de conforto térmico. O objetivo deste trabalho é avaliar diversos tipos e disposições de materiais em paredes de tijolos maciços, sob a ótica da térmica de edifícios. Para a realização dos experimentos, modelos em escala real foram confeccionados, instrumentados e acoplados a uma câmara térmica, desenvolvida especialmente para esse fim. O problema de transferência de calor foi modelado pela equação da energia, resolvida em Diferenças Finitas Centrais, utilizando-se o Método Implícito. As difusividades térmicas dos materiais foram calculadas resolvendo o Problema Inverso de transferência de calor. Também foi calculado o fluxo de calor e o custo total de cada alternativa, finalizando-se com a obtenção da relação termoeconômica para cada parede. Através da análise termoeconômica pode-se constatar que, apesar de o investimento inicial ser relativamente maior nas paredes mais espessas e/ou com isolamento térmico, estas apresentam um comportamento térmico muito superior às tradicionais. Notadamente, a parede com EPS na face exterior apresentou o melhor desempenho.

  12. Caloric beverages were major sources of energy among children and adults in Mexico, 1999-2012.

    Science.gov (United States)

    Stern, Dalia; Piernas, Carmen; Barquera, Simon; Rivera, Juan A; Popkin, Barry M

    2014-06-01

    Mexico, with 1 of the highest obesity prevalences in the world, instituted a 10% excise tax for any sugar-sweetened beverage (SSB) starting on 1 January 2014. Understanding the recent patterns and trends in beverage intake and sales in Mexico provides both background and baseline data for the importance of SSBs and other beverages in the Mexican diet. We analyzed a single 24-h dietary recall from 2 nationally representative surveys: the Mexican Nutrition Survey 1999 (n = 6049) and the National Health and Nutrition Survey 2012 (n = 10,343). To describe trends and patterns in beverages, we calculated the volume and energy intake per capita and per consumer and the proportion of consumers of each beverage group in each survey. A commercial sales dataset was used to describe beverage sales trends from 1999 to 2012. From 1999 to 2012, total daily energy from beverages increased among children aged 5-11 y (+45.3 kcal), females aged 12-19 y (+57.3 kcal), and adult females aged 20-49 y (+96.4 kcal) (P total daily energy intake per capita in children aged 1-19 y and adults aged ≥20 y, respectively. In 2012, flavored milk beverages, caloric soda, and high-fat milk were the top 3 major contributors to total daily energy intake per capita in all children aged 1-19 y. Caloric soda, caloric coffee/tea, and agua fresca were the top 3 major energy contributors in adults aged ≥20 y. From 1999 to 2012, sales of soda, fruit-flavored drinks, and flavored waters increased. In conclusion, consumption of several beverages with added sugars increased among children and adult females in Mexico. Because caloric soda is currently 1 of the top beverages consumed, a 10% tax on SSBs might help to significantly reduce added sugars intake in Mexico. © 2014 American Society for Nutrition.

  13. Influence of Caloric Vestibular Stimulation on Body Experience in Healthy Humans

    OpenAIRE

    Andreas eSchönherr; Christian-Albrecht eMay

    2016-01-01

    The vestibular system has more connections with and influence on higher cortical centers than previously thought. These interactions with higher cortical centers and the phenomena that they elicit require a structural intact cerebral cortex. To date, little is known about the role and influence of the vestibular system on one’s body experience. In this study we show that caloric vestibular stimulation (CVS) in healthy participants has an effect on the perceptive component of one’s body experi...

  14. Shifts in the Distribution of Mass Densities Is a Signature of Caloric Restriction in Caenorhabditis elegans

    OpenAIRE

    Alfonso Reina; Anand Bala Subramaniam; Anna Laromaine; Aravinthan D T Samuel; Whitesides, George M.

    2013-01-01

    Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The dens...

  15. Adipose-immune interactions during obesity and caloric restriction: reciprocal mechanisms regulating immunity and health span

    OpenAIRE

    Dixit, Vishwa Deep

    2008-01-01

    Increasing evidence suggests a tight coupling of metabolic and immune systems. This cross-talk mediated by neuroendocrine peptides as well as numerous cytokines and chemokines is believed to be responsible for integrating energy balance to immune function. These neuroendocrine-immune interactions are heightened during the state of chronic positive energy balance, as seen during obesity, and negative energy balance caused by caloric restriction (CR). Emerging evidence suggests that obesity may...

  16. The effects of cocoa supplementation, caloric restriction, and regular exercise, on oxidative stress markers of brain and memory in the rat model.

    Science.gov (United States)

    Radák, Zsolt; Silye, Gabriella; Bartha, Csaba; Jakus, Judit; Stefanovits-Bányai, Eva; Atalay, Mustafa; Marton, Orsolya; Koltai, Erika

    2013-11-01

    The effects of treadmill running (8 weeks, 5 times/week, 1h/day at 27 m/min), caloric restriction, and cocoa supplementation on brain function and oxidative stress markers were tested. The Morris maze test was used to appraise rat memory. Regular exercise significantly improved spatial learning performance. The level of oxidative stress was measured by the concentration of carbonylated proteins. The free radical concentration increased in brain of the training groups but not the controls. The content of reactive carbonyl derivates did not change with exercise, suggesting that the increased production of reactive oxygen species (ROS) were well tolerated in this experimental model. Caloric restriction (CR) decreased the accumulation of free radicals in the frontal lobe. The protein content of brain-derived neutrophic factors (BDNFs) was evaluated and changes did not occur either with exercise or cocoa supplementation treatments. These data did not show significant effects of the administration of cocoa (2% w/w) on the concentration of ROS, BDNF or on spatial memory. Conversely, exercise and CR can play a role in ROS generation and brain function. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Effects of caloric deprivation and satiety on sensitivity of the gustatory system

    Directory of Open Access Journals (Sweden)

    Zverev Yuriy P

    2004-02-01

    Full Text Available Abstract Background Sensitivity of the gustatory system could be modulated by a number of short-term and long-term factors such as body mass, gender, age, local and systemic diseases and pathological processes, excessive alcohol drinking, drug dependence, smoking, composition of oral fluid, state of oral hygiene, consumption of some foods among many others. A few studies have demonstrated the effects of hunger and caloric satiety on sensitivity of the gustatory system in obese humans and animals. The aim of the present study was to assess the effects of short-term caloric deprivation and satiety on recognition taste thresholds of healthy, non-smoking, non-drinking, non-obese young male subjects. The two-alternative forced-choice technique was used to measure taste threshold. Results Recognition thresholds for sucrose and salt were significantly lower during fasting state than after a meal (t = 2.23, P Conclusions Short-term caloric deprivation in our study model was associated with increased taste sensitivity to sweet and salty substances compared to satiated state while taste sensitivity to bitter substances was not affected by the conditions of measurements. Selective modulation of sensitivity of the gustatory system might reflect the different biological importance of salty, sweet and bitter qualities of taste.

  18. Importance of silvopastoral systems on caloric stress reduction in tropical livestock productions

    Directory of Open Access Journals (Sweden)

    Alexander Navas Panadero

    2010-06-01

    Full Text Available Livestock systems in Colombia have been developed taking concepts and technologies from the green revolution, where gramineous monocrop is privileged over arboreal cover in grazing lands. This model has not taken into account the climatic conditions of the different tropical ecosystems, in which variables as temperature, relative humidity and evaporation can limit the animal´s productive and reproductive efficiency, besides being a risk factor for illness occurrence in the herd. Bos Taurus and Bos Indicus breeds show termoneutral ranges where its genetic potential can be express. However, out of this comfort area animals can enter in caloric stress which in consequence reduces its performance and sometimes can end up causing death. Silvopastoral systems comprise several functions; it contributes to lessen caloric stress since temperature under the tree canopy can reach between 2 and 9°C lower in comparison to open pastures. Differences in temperature reduction have been found among silvopastoral systems and species, being the tree group arrangements and the species with high density canopy, those with superior effect. Interactions among components should be analyzed in order to design systems that incorporate enough arboreal cover to achieve caloric stress reductions, but without affecting forage production in pastures. Silvopastoral systems contribute to improve animal welfare.

  19. CALOR2012 XVth International Conference on Calorimetry in High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Akchurin, Nural .

    2015-05-04

    The International Conferences on Calorimetry in High Energy Physics, or the CALOR series, have always been where the calorimeter experts come together to review the state of calorimetry and bring forth new ideas every two years. The fteenth conference, CALOR2012, in Santa Fe was no exception. Although they were built roughly a decade ago, we are now witnessing the exceptional power of the LHC calorimeters and the crucial role they have been playing in the discovery of the 125 GeV Higgs-like boson. As we ruminate on the coming generation of experiments at the next (linear) collider and on the upgrades at the LHC, we are heartened by the substantial advances we made in calorimetry in the last decade. These advances will certainly help uncover new physics in the years to come, not only at colliders but also in astroparticle experiments that take advantage of natural elements such as air, water, and ice. The proceedings were published by the IOP in Journal of Physics, Vol 404 2011. The conference web site is calor2012.ttu.edu.

  20. Weight cycling and cancer: weighing the evidence of intermittent caloric restriction and cancer risk.

    Science.gov (United States)

    Thompson, Henry J; McTiernan, Anne

    2011-11-01

    Overweight and obese individuals frequently restrict caloric intake to lose weight. The resultant weight loss, however, typically is followed by an equal or greater weight gain, a phenomenon called weight cycling. Most attention to weight cycling has focused on identifying its detrimental effects, but preclinical experiments indicating that intermittent caloric restriction or fasting can reduce cancer risk have raised interest in potential benefits of weight cycling. Although hypothesized adverse effects of weight cycling on energy metabolism remain largely unsubstantiated, there is also a lack of epidemiologic evidence that intentional weight loss followed by regain of weight affects chronic-disease risk. In the limited studies of weight cycling and cancer, no independent effect on postmenopausal breast cancer but a modest enhancement of risk for renal cell carcinoma, endometrial cancer, and non-Hodgkin's lymphoma have been reported. An effect of either intermittent caloric restriction or fasting in protecting against cancer is not supported by the majority of rodent carcinogenesis experiments. Collectively, the data argue against weight cycling and indicate that the objective of energy balance-based approaches to reduce cancer risk should be to strive to prevent adult weight gain and maintain body weight within the normal range defined by body mass index.

  1. Temas de Física para Ingeniería: Temperatura y propagación del calor

    OpenAIRE

    Beléndez Vázquez, Augusto

    1992-01-01

    Acústica, fluidos y termodinámica: "Temperatura y propagación del calor". Introducción. Descripciones macroscópica y microscópica de un sistema. Equilibrio térmico y principio cero de la termodinámica. Termómetros y escala de temperaturas del gas ideal. Dilatación térmica. Propagación del calor.

  2. Ice air caloric test in chronic peripheral vestibular dysfunction with spontaneous nystagmus

    OpenAIRE

    Flavia Silveira dos Santos Cabral; Cristina Freitas Ganança; Fernando Freitas Ganança; Maurício Malavasi Ganança; Heloisa Helena Caovilla

    2008-01-01

    OBJETIVO: analisar o efeito da estimulação gelada com ar a 10ºC sobre o nistagmo pós-calórico em pacientes com vestibulopatias periféricas crônicas que apresentam nistagmo espontâneo com olhos fechados. MÉTODOS: 61 pacientes foram submetidos às estimulações com ar a 42, 18 e 10ºC. RESULTADOS: em 42 casos (69,8%) foram encontrados valores anormais de preponderância direcional e/ou de predomínio labiríntico a 42 e 18ºC. A prova a 10ºC apresentou valores de assimetria dentro dos padrões de norma...

  3. Caloric Beverages Were Major Sources of Energy among Children and Adults in Mexico, 1999–2012123

    Science.gov (United States)

    Stern, Dalia; Piernas, Carmen; Barquera, Simon; Rivera, Juan A.; Popkin, Barry M.

    2014-01-01

    Mexico, with 1 of the highest obesity prevalences in the world, instituted a 10% excise tax for any sugar-sweetened beverage (SSB) starting on 1 January 2014. Understanding the recent patterns and trends in beverage intake and sales in Mexico provides both background and baseline data for the importance of SSBs and other beverages in the Mexican diet. We analyzed a single 24-h dietary recall from 2 nationally representative surveys: the Mexican Nutrition Survey 1999 (n = 6049) and the National Health and Nutrition Survey 2012 (n = 10,343). To describe trends and patterns in beverages, we calculated the volume and energy intake per capita and per consumer and the proportion of consumers of each beverage group in each survey. A commercial sales dataset was used to describe beverage sales trends from 1999 to 2012. From 1999 to 2012, total daily energy from beverages increased among children aged 5–11 y (+45.3 kcal), females aged 12–19 y (+57.3 kcal), and adult females aged 20–49 y (+96.4 kcal) (P agua fresca (fruit water made in stalls or at home, usually with added sugars), and fruit drinks among children aged 5–11 y and females aged 12–19 y and caloric coffee/tea, soda, and agua fresca among adult females aged 20–49 y. In 2012, beverages represented 17.5% (325 kcal) and 19.0% (382 kcal) of the total daily energy intake per capita in children aged 1–19 y and adults aged ≥20 y, respectively. In 2012, flavored milk beverages, caloric soda, and high-fat milk were the top 3 major contributors to total daily energy intake per capita in all children aged 1–19 y. Caloric soda, caloric coffee/tea, and agua fresca were the top 3 major energy contributors in adults aged ≥20 y. From 1999 to 2012, sales of soda, fruit-flavored drinks, and flavored waters increased. In conclusion, consumption of several beverages with added sugars increased among children and adult females in Mexico. Because caloric soda is currently 1 of the top beverages consumed, a 10% tax

  4. Glucocorticoid antagonism limits adiposity rebound and glucose intolerance in young male rats following the cessation of daily exercise and caloric restriction.

    Science.gov (United States)

    Teich, Trevor; Dunford, Emily C; Porras, Deanna P; Pivovarov, Jacklyn A; Beaudry, Jacqueline L; Hunt, Hazel; Belanoff, Joseph K; Riddell, Michael C

    2016-07-01

    Severe caloric restriction (CR), in a setting of regular physical exercise, may be a stress that sets the stage for adiposity rebound and insulin resistance when the food restriction and exercise stop. In this study, we examined the effect of mifepristone, a glucocorticoid (GC) receptor antagonist, on limiting adipose tissue mass gain and preserving whole body insulin sensitivity following the cessation of daily running and CR. We calorically restricted male Sprague-Dawley rats and provided access to voluntary running wheels for 3 wk followed by locking of the wheels and reintroduction to ad libitum feeding with or without mifepristone (80 mg·kg(-1)·day(-1)) for 1 wk. Cessation of daily running and CR increased HOMA-IR and visceral adipose mass as well as glucose and insulin area under the curve during an oral glucose tolerance test vs. pre-wheel lock exercised rats and sedentary rats (all P < 0.05). Insulin sensitivity and glucose tolerance were preserved and adipose tissue mass gain was attenuated by daily mifepristone treatment during the post-wheel lock period. These findings suggest that following regular exercise and CR there are GC-induced mechanisms that promote adipose tissue mass gain and impaired metabolic control in healthy organisms and that this phenomenon can be inhibited by the GC receptor antagonist mifepristone. Copyright © 2016 the American Physiological Society.

  5. Obesity, abdominal obesity, physical activity, and caloric intake in US adults: 1988 to 2010.

    Science.gov (United States)

    Ladabaum, Uri; Mannalithara, Ajitha; Myer, Parvathi A; Singh, Gurkirpal

    2014-08-01

    Obesity and abdominal obesity are associated independently with morbidity and mortality. Physical activity attenuates these risks. We examined trends in obesity, abdominal obesity, physical activity, and caloric intake in US adults from 1988 to 2010. Univariate and multivariate analyses were performed using National Health and Nutrition Examination Survey data. Average body mass index (BMI) increased by 0.37% (95% confidence interval [CI], 0.30-0.44) per year in both women and men. Average waist circumference increased by 0.37% (95% CI, 0.30-0.43) and 0.27% (95% CI, 0.22-0.32) per year in women and men, respectively. The prevalence of obesity and abdominal obesity increased substantially, as did the prevalence of abdominal obesity among overweight adults. Younger women experienced the greatest increases. The proportion of adults who reported no leisure-time physical activity increased from 19.1% (95% CI, 17.3-21.0) to 51.7% (95% CI, 48.9-54.5) in women, and from 11.4% (95% CI, 10.0-12.8) to 43.5% (95% CI, 40.7-46.3) in men. Average daily caloric intake did not change significantly. BMI and waist circumference trends were associated with physical activity level but not caloric intake. The associated changes in adjusted BMIs were 8.3% (95% CI, 6.9-9.6) higher among women and 1.7% (95% CI, 0.68-2.8) higher among men with no leisure-time physical activity compared with those with an ideal level of leisure-time physical activity. Our analyses highlight important dimensions of the public health problem of obesity, including trends in younger women and in abdominal obesity, and lend support to the emphasis placed on physical activity by the Institute of Medicine. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Nutrients, not caloric restriction, extend lifespan in Queensland fruit flies (Bactrocera tryoni).

    Science.gov (United States)

    Fanson, Benjamin G; Weldon, Christopher W; Pérez-Staples, Diana; Simpson, Stephen J; Taylor, Phillip W

    2009-09-01

    Caloric restriction (CR) has been widely accepted as a mechanism explaining increased lifespan (LS) in organisms subjected to dietary restriction (DR), but recent studies investigating the role of nutrients have challenged the role of CR in extending longevity. Fuelling this debate is the difficulty in experimentally disentangling CR and nutrient effects due to compensatory feeding (CF) behaviour. We quantified CF by measuring the volume of solution imbibed and determined how calories and nutrients influenced LS and fecundity in unmated females of the Queensland fruit fly, Bactocera tryoni (Diptera: Tephritidae). We restricted flies to one of 28 diets varying in carbohydrate:protein (C:P) ratios and concentrations. On imbalanced diets, flies overcame dietary dilutions, consuming similar caloric intakes for most dilutions. The response surface for LS revealed that increasing C:P ratio while keeping calories constant extended LS, with the maximum LS along C:P ratio of 21:1. In general, LS was reduced as caloric intake decreased. Lifetime egg production was maximized at a C:P ratio of 3:1. When given a choice of separate sucrose and yeast solutions, each at one of five concentrations (yielding 25 choice treatments), flies regulated their nutrient intake to match C:P ratio of 3:1. Our results (i) demonstrate that CF can overcome dietary dilutions; (ii) reveal difficulties with methods presenting fixed amounts of liquid diet; (iii) illustrate the need to measure intake to account for CF in DR studies and (iv) highlight nutrients rather than CR as a dominant influence on LS.

  7. [Caloric value and ash content of dominant plants in plantation communities in Heshan of Guangdong, China].

    Science.gov (United States)

    Zeng, Xiao-ping; Cai, Xi-an; Zhao, Ping; Rao, Xing-quan

    2009-03-01

    Different parts of twenty dominant plant species in five plantation communities on the subtropical hilly lands in Heshan of Gunagdong as well as the litters from three of the five plantation communities were sampled, and their gross caloric value (GCV) and ash content were measured by using a PARR-1281 oxygen bomb calorimeter and a muffle furnace. Based on the measurements, the ash-free caloric value (AFCV) of the samples was calculated, and the characteristics of caloric value and ash content of the samples, according to plant part, individual, and plant growth form, were analyzed. The results showed that the GCV and AFCV of leaf, branch, stem wood, stem bark, and root were in the range of 10.7-22.17 kJ x g(-1) and 13.89-23.04 kJ x g(-1), respectively. The GCV and AFCV of leaf were significantly higher than those of other parts (P shrub layer (19.46 kJ x g(-1) > herb layer (18.77 kJ x g(-1)), with indigenous coniferous tree (19.86 kJ x g(-1)) > indigenous broad-leaved tree (19.55 kJ x g(-1)) > exotic eucalyptus (19.18 kJ x g(-1)), while the mean ash content was just the opposite. In Acacia mangium, coniferous, and Schima plantation communities, the GCV and AFCV of litters were higher than those of various plant parts (P mangium and coniferous plantations had higher mean GCV and AFCV than the litters and fresh leaves of tree layer, while the fresh leaves of tree layer in Schima plantation showed higher mean GCV and AFCV.

  8. Olas de calor e influencia urbana en Madrid y su área metropolitana

    Directory of Open Access Journals (Sweden)

    Fernández García, F.

    2008-12-01

    Full Text Available The frequency and duration of the warmest temperature episodes, a common phenomenon under the continental Mediterranean conditions of the Spanish Southern Meseta, has increased in the Madrid area since the 80´s, although their magnitude remains unchanged. The effect of the urban environment on those extreme events has exacerbated the heat load due to the persistence of the high temperatures along the night time hours. Nevertheless, the diversity of the urban morphology introduces a spatial variability on the strength of this nocturnal heat load, aggravating it in the densely urbanized areas and mitigating it in the vicinities of the green areas.

    La frecuencia y duración de los episodios cálidos extremos, un fenómeno habitual en el clima mediterráneo continental de la Meseta Meridional, ha aumentado en el área de Madrid desde los años noventa, aunque su magnitud permanece constante. En el interior de la aglomeración urbana, el efecto general de la ciudad sobre estos eventos climáticos extremos ha supuesto una exacerbación del calor, no tanto por un aumento de la temperatura máxima, como por una persistencia del calor en las horas nocturnas. No obstante, la diversidad de la morfología urbana introduce variaciones espaciales en la intensidad de este calor nocturno, agravando sus efectos en las áreas densamente urbanizadas y mitigándolos en las proximidades de las áreas verdes.

  9. Influence on longevity of blueberry, cinnamon, green and black tea, pomegranate, sesame, curcumin, morin, pycnogenol, quercetin, and taxifolin fed iso-calorically to long-lived, F1 hybrid mice.

    Science.gov (United States)

    Spindler, Stephen R; Mote, Patricia L; Flegal, James M; Teter, Bruce

    2013-04-01

    Phytonutrients reportedly extend the life span of Caenorhabditis elegans, Drosophila, and mice. We tested extracts of blueberry, pomegranate, green and black tea, cinnamon, sesame, and French maritime pine bark (Pycnogenol and taxifolin), as well as curcumin, morin, and quercetin for their effects on the life span of mice. While many of these phytonutrients reportedly extend the life span of model organisms, we found no significant effect on the life span of male F1 hybrid mice, even though the dosages used reportedly produce defined therapeutic end points in mice. The compounds were fed beginning at 12 months of age. The control and treatment groups were iso-caloric with respect to one another. A 40% calorically restricted and other groups not reported here did experience life span extension. Body weights were un-changed relative to controls for all but two supplemented groups, indicating most supplements did not change energy absorption or utilization. Tea extracts with morin decreased weight, whereas quercetin, taxifolin, and Pycnogenol together increased weight. These changes may be due to altered locomotion or fatty acid biosynthesis. Published reports of murine life span extension using curcumin or tea components may have resulted from induced caloric restriction. Together, our results do not support the idea that isolated phytonutrient anti-oxidants and anti-inflammatories are potential longevity therapeutics, even though consumption of whole fruits and vegetables is associated with enhanced health span and life span.

  10. Roles of Caloric Restriction, Ketogenic Diet and Intermittent Fasting during Initiation, Progression and Metastasis of Cancer in Animal Models: A Systematic Review and Meta-Analysis: e115147

    National Research Council Canada - National Science Library

    Mengmeng Lv; Xingya Zhu; Hao Wang; Feng Wang; Wenxian Guan

    2014-01-01

      Background The role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments...

  11. The late-luteal leptin level, caloric intake and eating behaviors among women with premenstrual dysphoric disorder.

    Science.gov (United States)

    Ko, Chih-Hung; Yen, Cheng-Fang; Long, Cheng-Yu; Kuo, Yu-Ting; Chen, Cheng-Sheng; Yen, Ju-Yu

    2015-06-01

    A marked increased in food intake in the late-luteal phase is a characteristic symptom of premenstrual dysphoric disorder (PMDD). The aim of the study was to evaluate the leptin level, caloric intake, and eating behaviors of women with PMDD across the menstrual cycle among normal-weight and overweight subjects, respectively. A total of 62 women with PMDD and 69 controls were recruited following psychiatric interviewing and underwent prospective investigation. The leptin level, caloric intake, and three factors related to eating behavior were assessed in both the late-luteal and follicular phases. The women with PMDD had greater increases in caloric intake, sweet caloric intake, and uncontrolled eating in the late-luteal phase than the controls. Among the normal-weight women, the leptin level was negatively correlated with caloric intake. The normal-weight women with PMDD had a lower leptin level, a lower leptin/body fat percentage (BFP), a higher caloric intake, and higher uncontrolled eating and emotional eating in the late-luteal phase than the normal-weight controls. Their leptin level was correlated negatively with sweet caloric intake. On the other hand, the overweight women with PMDD had a higher leptin level than the normal-weight women with PMDD and no decline was observed in their leptin level in the late-luteal phase. There were no differences in the leptin level between the overweight women with PMDD and the overweight controls. They also had a higher sweet caloric intake and higher uncontrolled eating and emotional eating than the overweight controls. A decline in the leptin level is associated with late-luteal overeating among normal-weight women with PMDD. Hyperleptinemia and a high sweet caloric intake of overweight women with PMDD should be monitored and addressed in order to attenuate the risk of leptin resistance. The detailed roles of leptin and other psycho-neuro-endocrinology factors in the mechanism of overeating among women with PMDD should

  12. Evaluation of a direct contact heat exchanger; Evaluacion de un intercambiador de calor de contacto directo

    Energy Technology Data Exchange (ETDEWEB)

    Siqueiros, J.; Bonilla, O. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    In this paper the application areas of the direct contact heat exchangers is discussed, as well as its main characteristics. A description is made of the experimental equipment designed and built at pilot scale including the instrumentation employed. The methodology employed as well as the analysis and the discussion of the results are also presented. [Espanol] Se mencionan las areas de aplicacion de los intercambiadores de calor de contacto directo, asi como sus caracteristicas principales. Se describe el equipo experimental a nivel piloto disenado y construido incluyendo la instrumentacion utilizada. Se presenta la metodologia empleada asi como el analisis y discusion de los resultados.

  13. Diseño de una máquina de rotomoldeo sin aporte de calor

    OpenAIRE

    Montes Cale, Pablo

    2016-01-01

    El presente proyecto consiste en el diseño de una máquina de rotomoldeo sin aporte de calor con la que se puedan generar piezas huecas de plástico de resina autocurable detallando los tipos de estas resinas utilizadas en este sistema al principio. La máquina está construida mediante un sistema modular para facilitar la reparación o el cambio de piezas ante posible rotura. El movimiento de la máquina está gobernado mediante un variador de frecuencia acoplado a un motorreducto...

  14. Identificación de incrustaciones en ciclones recuperadores de calor de hornos DOPOL

    Directory of Open Access Journals (Sweden)

    Triviño Vázquez, Fernando

    1979-12-01

    Full Text Available Not avaible

    En un ciclón recuperador de calor, situado a la entrada del horno de clinquerización tipo DOPOL, se producían unas incrustaciones sedimentarias que terminaban produciendo la obstrucción del ciclón. Simultáneamente aparecían dificultades de marcha durante el crecimiento, por sedimentación- fusión, de dichas incrustaciones. Finalmente era necesaria la parada del horno para la limpieza del ciclón.

  15. Transferencia molecular de calor, masa y/o cantidad de movimiento

    OpenAIRE

    Betancourt Grajales, Ramiro

    2008-01-01

    Este texto fue diseñado para proveer un tratamiento integrado de las tres áreas del transporte: impulso, calor y masa. Las similitudes entre las leyes de flujo permiten aplicar directamente analogías en el cálculo del transporte haciendo una economía en el esfuerzo docente–discente acorde con las pedagogías intensivas. Muchas de las ecuaciones básicas son matemáticamente idénticas cuando se expresan en términos de las variables y densidades de flujo generalizadas. El texto comienza con tra...

  16. Targeting energy metabolism in brain cancer with calorically restricted ketogenic diets.

    Science.gov (United States)

    Seyfried, Thomas N; Kiebish, Michael; Mukherjee, Purna; Marsh, Jeremy

    2008-11-01

    Information is presented on the calorically restricted ketogenic diet (CRKD) as an alternative therapy for brain cancer. In contrast to normal neurons and glia, which evolved to metabolize ketone bodies as an alternative fuel to glucose under energy-restricted conditions, brain tumor cells are largely glycolytic due to mitochondrial defects and have a reduced ability to metabolize ketone bodies. The CRKD is effective in managing brain tumor growth in animal models and in patients, and appears to act through antiangiogenic, anti-inflammatory, and proapoptotic mechanisms.

  17. Relationship of Mediterranean diet and caloric intake to phenoconversion in Huntington disease.

    Science.gov (United States)

    Marder, Karen; Gu, Yian; Eberly, Shirley; Tanner, Caroline M; Scarmeas, Nikolaos; Oakes, David; Shoulson, Ira

    2013-11-01

    Adherence to Mediterranean-type diet (MeDi) may delay onset of Alzheimer and Parkinson diseases. Whether adherence to MeDi affects time to phenoconversion in Huntington disease (HD), a highly penetrant, single-gene disorder, is unknown. To determine if MeDi modifies the time to clinical onset of HD (phenoconversion) in premanifest carriers participating in Prospective Huntington at Risk Observational Study (PHAROS), and to examine the effects of body mass index and caloric intake on time to phenoconversion. A prospective cohort study of 41 Huntington study group sites in the United States and Canada involving 1001 participants enrolled in PHAROS between July 1999 and January 2004 who were followed up every 9 months until 2010. A total of 211 participants aged 26 to 57 years had an expanded CAG repeat length (≥ 37). A semiquantitative food frequency questionnaire was administered 33 months after baseline. We calculated daily gram intake for dairy, meat, fruit, vegetables, legumes, cereals, fish, monounsaturated and saturated fatty acids, and alcohol and constructed MeDi scores (0-9); higher scores indicate higher adherence. Demographics, medical history, body mass index, and Unified Huntington's Disease Rating Scale (UHDRS) score were collected. Cox proportional hazards regression models to determine the association of MeDi and phenoconversion. RESULTS Age, sex, caloric intake, education status, and UHDRS motor scores did not differ among MeDi tertiles (0-3, 4-5, and 6-9). The highest body mass index was associated with the lowest adherence to MeDi. Thirty-one participants phenoconverted. In a model adjusted for age, CAG repeat length, and caloric intake, MeDi was not associated with phenoconversion (P for trend = 0.14 for tertile of MeDi, and P = .22 for continuous MeDi). When individual components of MeDi were analyzed, higher dairy consumption (hazard ratio, 2.36; 95% CI, 1.0-5.57; P = .05) and higher caloric intake (P = .04) were associated with risk of

  18. Efectos no-newtonianos en un cambiador de calor comercial de doble tubo para aplicaciones alimentarias

    OpenAIRE

    Molina Sánchez, Alberto Aurelio

    2006-01-01

    El objetivo del presente proyecto es evaluar la importancia que los efectos no newtonianos de los productos alimentarios ejercen sobre el flujo y la transferencia de calor en procesos industriales. En concreto, el estudio se basa en el comportamiento reológico seudoplástico mostrado por el cremogenado de melocotón durante un proceso de enfriamiento. El proyecto consta de una primera parte de recopilación bibliográfica en la que se exponen los conocimientos necesarios para poder llevar a cabo ...

  19. Tecnologías emergentes para la conservación de alimentos sin calor

    OpenAIRE

    Fernández Molina, Juan José; Barbosa-Cánovas, Gustavo V.; Swanson, Barry G.

    2001-01-01

    Not available

    Se han investigado los principios básicos de tres tecnologías emergentes para pasteurizar y esterilizar alimentos sin empleo del calor Mediante numerosos estudios se ha comprobado la efectividad de los campos eléctricos pulsantes de alta intensidad (CEPAI), los pulsos de luz (PL) y los campos magnéticos oscilantes (CMO) en la destrucción de microorganismos y enzimas de sistemas alimentarios. En la inactivación microbiana por CEPA!, el blanco principal es la me...

  20. Coeficientes de transferencia de calor en enfriadores de mineral laterítico a escala piloto

    OpenAIRE

    Ángel Legrá-Legrá; Yudmila Spencer-Rodríguez; Yoalbys Retirado-Mediaceja; Ángel O. Columbié-Navarro; Marbelis Lamorú-Urgellés; Ever Góngora-Leyva

    2009-01-01

    En la Planta de Hornos de Reducción de la empresa niquelera Ernesto Guevara las elevadas temperaturas del mineral reducido a la salida de los enfriadores (coolers) afectan el desarrollo eficiente del proceso de lixiviación. Se realizó una investigación, a escala piloto, en los enfriadores de mineral reducido con el fin de evaluar el comportamiento de los parámetros de transferencia de calor que caracterizan el proceso; para ello se registraron los valores de temperatura del agua y del flujo y...

  1. Uso de transdutores de fluxo de calor no estudo da transferência de calor em alimentos embalados The use of heat flux transducers to study heat transfer in canned foods

    OpenAIRE

    Carciofi, B.; S. Güths; J. B. Laurindo

    2002-01-01

    A densidade de fluxo de calor que atravessa uma superfície é classicamente determinada mediante a medição das temperaturas apropriadas e da aplicação da Lei de Fourier. Uma alternativa a esse procedimento é a utilização de transdutores de fluxo de calor, os quais geram um sinal elétrico proporcional ao fluxo térmico que os atravessa. Neste trabalho, processos de aquecimento e de resfriamento de alimentos foram estudados em laboratório, utilizando-se um recipiente de vidro cilíndrico para simu...

  2. Caloric vestibular stimulation as a treatment for conversion disorder: A case report and medical hypothesis

    Directory of Open Access Journals (Sweden)

    Michael eNoll-Hussong

    2014-06-01

    Full Text Available Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation (CVS has been demonstrated to modulate transiently a variety of cognitive functions associated with brain activations, especially in the temporal-parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure.

  3. Coeficientes de transferencia de calor en enfriadores de mineral laterítico a escala piloto

    Directory of Open Access Journals (Sweden)

    Ángel Legrá-Legrá

    2009-03-01

    Full Text Available En la Planta de Hornos de Reducción de la empresa niquelera Ernesto Guevara las elevadas temperaturas del mineral reducido a la salida de los enfriadores (coolers afectan el desarrollo eficiente del proceso de lixiviación. Se realizó una investigación, a escala piloto, en los enfriadores de mineral reducido con el fin de evaluar el comportamiento de los parámetros de transferencia de calor que caracterizan el proceso; para ello se registraron los valores de temperatura del agua y del flujo y la temperatura del mineral, tanto a la entrada como a la salida de la instalación, para valores de flujos de 10 y 19 l/min. Como resultado se obtuvo el procedimiento de cálculo para determinar los coeficientes superficiales de transferencia de calor por unidad de longitud. Se encontró que en los enfriadores de mineral reducido predominan la conducción y radiación del mineral a la pared interior del cilindro cubierta por el sólido así como la convección y evaporación del agua al medio que permite dirigir las acciones hacia estos elementos para aumentar la eficiencia de la instalación.

  4. In-shell pistachio nuts reduce caloric intake compared to shelled nuts.

    Science.gov (United States)

    Honselman, Carla S; Painter, James E; Kennedy-Hagan, Karla J; Halvorson, Amber; Rhodes, Kathy; Brooks, Tamatha L; Skwir, Kaitlin

    2011-10-01

    It was hypothesized that consuming in-shell pistachios, compared to shelled pistachios, causes individuals to consume less. A convenience sample of students at a mid-western university (n=140) was recruited, asking them to evaluate a variety of brands of pistachios. A survey at the end of class determined fullness and satisfaction. Subjects entering the classroom were given a 16-ounce cup and asked to self-select a portion of pistachios. Portion weight was recorded and subjects consumed pistachios at their leisure during class. At class end, pistachios remaining in the cup were weighed and total consumption by weight was determined. The caloric content of each portion was then calculated. In condition one, subjects offered in-shell pistachios consumed an average of 125 calories. In condition two, subjects offered shelled pistachios consumed an average of 211 calories; a difference of 86 calories. Subjects in condition one consumed 41% fewer calories compared to subjects in condition two (p≤.01). Fullness and satisfaction ratings were not significantly different (p≥.01). Caloric intake was influenced by the initial form of the food. The difference in calories consumed may be due to the additional time needed to shell the nuts or the extra volume perceived when consuming in-shell nuts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Transferencia de calor en la colada continua de aceros. I parte. El molde

    Directory of Open Access Journals (Sweden)

    Cicutti, C.

    1997-10-01

    Full Text Available The continuous casting mold plays the important role of receiving the liquid steel and allowing an uniform and defect free solidified skin to be developed. In this work, the different heat transfer mechanisms which are present from the liquid steel to the mold cooling water are reviewed. The effect of operating variables on heat extraction and the relationship between global and distributed heat flux are also analyzed.

    El molde de colada continua cumple la importante función de recibir el acero líquido y permitir que se desarrolle una capa solidificada uniforme y libre de defectos. En este trabajo se revisan los distintos mecanismos implicados en el proceso de transferencia de calor, desde el acero líquido hasta el agua de refrigeración del molde. Se analiza también el efecto de las distintas variables de funcionamiento en la extracción calórica producida y la relación entre el flujo global de calor y su distribución a lo largo del molde.

  6. Comparação dos resultados da aplicação de calor local e crioterapia no alongamento de isquiotibiais em adolescentes

    Directory of Open Access Journals (Sweden)

    Nathália Fernandez de Castro

    2017-04-01

    Full Text Available Objetivo: avaliar a eficácia de dois recursos térmicos no alongamento de isquiotibiais em adolescentes. Método: estudo clínico controlado não randomizado com 45 adolescentes do sexo masculino de 13 e 16 anos. Indivíduos com lesão musculoesquelética em membros inferiores, déficit de sensibilidade ou praticantes de atividade física que possibilitasse ganho da amplitude de movimento (ADM foram excluídos do estudo. A amostra foi dividida em três grupos, sendo crioterapia, calor local e controle. Os grupos foram avaliados no mesmo dia, em horários diferentes. Com o auxílio de um goniômetro, utilizado antes e após a intervenção, foi solicitada uma flexão de quadril juntamente com uma extensão de joelho e dorsiflexão de tornozelo até o máximo de amplitude possível. Após a primeira medida, foram realizadas as intervenções com bolsas de gel, por 20 minutos, em temperatura abaixo de zero graus Celsius no grupo 1, e calor no grupo 2, cuja temperatura era em média de 43°C, diretamente sobre o ventre muscular. As temperaturas foram controladas com o auxílio de um termômetro. Após a intervenção, foi realizada nova medida. No grupo controle foram realizadas apenas duas medidas com o goniômetro espaçadas por 20 minutos. Para a estatística descritiva foram utilizadas a média e o desvio padrão. Para a comparação entre grupos foi utilizada a análise de variância de uma via com post-hoc de Tukey. Já para a análise dentro de cada grupo foi utilizado o teste t pareado. Para a análise dentro de cada grupo foi utilizado o teste t pareado. Resultados: os dois grupos experimentais (crioterapia e calor local aumentaram efetivamente a ADM em relação ao grupo controle com p

  7. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer

    Directory of Open Access Journals (Sweden)

    Zhou Weihua

    2007-02-01

    Full Text Available Abstract Background Malignant brain cancer persists as a major disease of morbidity and mortality in adults and is the second leading cause of cancer death in children. Many current therapies for malignant brain tumors fail to provide long-term management because they ineffectively target tumor cells while negatively impacting the health and vitality of normal brain cells. In contrast to brain tumor cells, which lack metabolic flexibility and are largely dependent on glucose for growth and survival, normal brain cells can metabolize both glucose and ketone bodies for energy. This study evaluated the efficacy of KetoCal®, a new nutritionally balanced high fat/low carbohydrate ketogenic diet for children with epilepsy, on the growth and vascularity of a malignant mouse astrocytoma (CT-2A and a human malignant glioma (U87-MG. Methods Adult mice were implanted orthotopically with the malignant brain tumors and KetoCal® was administered to the mice in either unrestricted amounts or in restricted amounts to reduce total caloric intake according to the manufacturers recommendation for children with refractory epilepsy. The effects KetoCal® on tumor growth, vascularity, and mouse survival were compared with that of an unrestricted high carbohydrate standard diet. Results KetoCal® administered in restricted amounts significantly decreased the intracerebral growth of the CT-2A and U87-MG tumors by about 65% and 35%, respectively, and significantly enhanced health and survival relative to that of the control groups receiving the standard low fat/high carbohydrate diet. The restricted KetoCal® diet reduced plasma glucose levels while elevating plasma ketone body (β-hydroxybutyrate levels. Tumor microvessel density was less in the calorically restricted KetoCal® groups than in the calorically unrestricted control groups. Moreover, gene expression for the mitochondrial enzymes, β-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-ketoacid Co

  8. The calorically restricted ketogenic diet, an effective alternative therapy for malignant brain cancer.

    Science.gov (United States)

    Zhou, Weihua; Mukherjee, Purna; Kiebish, Michael A; Markis, William T; Mantis, John G; Seyfried, Thomas N

    2007-02-21

    Malignant brain cancer persists as a major disease of morbidity and mortality in adults and is the second leading cause of cancer death in children. Many current therapies for malignant brain tumors fail to provide long-term management because they ineffectively target tumor cells while negatively impacting the health and vitality of normal brain cells. In contrast to brain tumor cells, which lack metabolic flexibility and are largely dependent on glucose for growth and survival, normal brain cells can metabolize both glucose and ketone bodies for energy. This study evaluated the efficacy of KetoCal, a new nutritionally balanced high fat/low carbohydrate ketogenic diet for children with epilepsy, on the growth and vascularity of a malignant mouse astrocytoma (CT-2A) and a human malignant glioma (U87-MG). Adult mice were implanted orthotopically with the malignant brain tumors and KetoCal was administered to the mice in either unrestricted amounts or in restricted amounts to reduce total caloric intake according to the manufacturers recommendation for children with refractory epilepsy. The effects KetoCal on tumor growth, vascularity, and mouse survival were compared with that of an unrestricted high carbohydrate standard diet. KetoCal administered in restricted amounts significantly decreased the intracerebral growth of the CT-2A and U87-MG tumors by about 65% and 35%, respectively, and significantly enhanced health and survival relative to that of the control groups receiving the standard low fat/high carbohydrate diet. The restricted KetoCal diet reduced plasma glucose levels while elevating plasma ketone body (beta-hydroxybutyrate) levels. Tumor microvessel density was less in the calorically restricted KetoCal groups than in the calorically unrestricted control groups. Moreover, gene expression for the mitochondrial enzymes, beta-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-ketoacid CoA transferase, was lower in the tumors than in the contralateral normal

  9. Transferencia de calor en el secado solar a la intemperie de menas lateríticas ferroniquelíferas

    Directory of Open Access Journals (Sweden)

    Yoalbys Retirado-Mediaceja

    2011-03-01

    Full Text Available En Moa, las menas lateríticas son sometidas a secado solar a la intemperie para reducirles el contenido de humedad antes de incorporarlas al proceso de secado térmico convencional. Este artículo evalúa los procesos de transferencia de calor fundamentales que tienen lugar durante el secado natural con el propósito de determinar el modo predominante de transferencia de calor. En dos pilas de menas lateríticas expuestas a secado solar natural se midieron las variables climatológicas y termodinámicas que influyen en la transferencia de calor por convección y radiación durante el secado y se calcularon, además, los criterios adimensionales para determinar el tipo predominante de convección. Se comprobó que durante el secado solar a la intemperie predomina la convección y que en las condiciones de experimentación analizadas la radiación tuvo una incidencia secundaria. Los resultados evidenciaron que el calor se transfiere por convección libre, forzada y mixta, predominando la forzada, para la cual los coeficientes de transferencia de calor mínimos y máximos mostraron pequeñas variaciones entre ambas pilas. Los flujos de calor por convección promedios fueron 978,74 y 1 156,58 W/m2 , mientras que los flujos por radiación ascendieron a 324,71 y 355,36 W/m2 para las pilas #1 y #2, respectivamente.

  10. Overeat today, skip the scale tomorrow: An examination of caloric intake predicting nonadherence to daily self-weighing.

    Science.gov (United States)

    Tanenbaum, Molly L; Ross, Kathryn M; Wing, Rena R

    2016-11-01

    Daily self-weighing is an effective weight loss strategy. Little is known about "micro" factors influencing nonadherence to self-weighing (e.g., daily overeating). It was hypothesized that increased caloric intake on a given day would increase odds of not self-weighing the following day. Daily self-reports of weight and caloric intake were collected from 74 adults with overweight and obesity (mean BMI = 31.2 ± 4.5 kg/m2 , age = 50.6 ± 10 years, 69% female, 87% Caucasian) throughout a 12-week Internet-based weight management intervention. Multilevel logistic regression investigated odds of nonadherence to self-weighing on a given day based on the previous day's caloric intake. Self-monitoring adherence was high (weights: 87%; calories: 85%); adherence was associated with greater 12-week weight loss (weighing: r = -0.24, P = 0.04; calories: r = -0.26, P = 0.04). Increased caloric intake on a given day, relative to the individual's average intake, was associated with increased odds of nonadherence to self-weighing the next day (F(1,5106)  = 12.66, P = 0.0004, β = 0.001). For example, following a day of eating 300 calories more than usual, odds of not self-weighing increased by 1.33. Odds of nonadherence to self-weighing increased following a day with higher-than-usual caloric intake. Weight management interventions collecting daily self-monitoring data could provide support to participants who report increased caloric intake to prevent self-weighing nonadherence. © 2016 The Obesity Society.

  11. Addressing the policy cacophony does not require more evidence: an argument for reframing obesity as caloric overconsumption.

    Science.gov (United States)

    Shelley, Jacob J

    2012-11-30

    Numerous policies have been proposed to address the public health problem of obesity, resulting in a policy cacophony. The noise of so many policy options renders it difficult for policymakers to determine which policies warrant implementation. This has resulted in calls for more and better evidence to support obesity policy. However, it is not clear that evidence is the solution. This paper argues that to address the policy cacophony it is necessary to rethink the problem of obesity, and more specifically, how the problem of obesity is framed. This paper argues that the frame "obesity" be replaced by the frame "caloric overconsumption", concluding that the frame caloric overconsumption can overcome the obesity policy cacophony. Frames are important because they influence public policy. Understood as packages that define issues, frames influence how best to approach a problem. Consequently, debates over public policy are considered battles over framing, with small shifts in how an issue is framed resulting in significant changes to the policy environment. This paper presents a rationale for reframing the problem of obesity as caloric overconsumption. The frame "obesity" contributes to the policy cacophony by including policies aimed at both energy output and energy input. However, research increasingly demonstrates that energy input is the primary cause of obesity, and that increases in energy input are largely attributable to the food environment. By focusing on policies that aim to prevent increases in energy input, the frame caloric overconsumption will reduce the noise of the obesity policy cacophony. While the proposed frame will face some challenges, particularly industry opposition, policies aimed at preventing caloric overconsumption have a clearer focus, and can be more politically palatable if caloric overconsumption is seen as an involuntary risk resulting from the food environment. The paper concludes that policymakers will be able to make better sense

  12. Addressing the policy cacophony does not require more evidence: an argument for reframing obesity as caloric overconsumption

    Directory of Open Access Journals (Sweden)

    Shelley Jacob J

    2012-11-01

    Full Text Available Abstract Background Numerous policies have been proposed to address the public health problem of obesity, resulting in a policy cacophony. The noise of so many policy options renders it difficult for policymakers to determine which policies warrant implementation. This has resulted in calls for more and better evidence to support obesity policy. However, it is not clear that evidence is the solution. This paper argues that to address the policy cacophony it is necessary to rethink the problem of obesity, and more specifically, how the problem of obesity is framed. This paper argues that the frame “obesity” be replaced by the frame “caloric overconsumption”, concluding that the frame caloric overconsumption can overcome the obesity policy cacophony. Discussion Frames are important because they influence public policy. Understood as packages that define issues, frames influence how best to approach a problem. Consequently, debates over public policy are considered battles over framing, with small shifts in how an issue is framed resulting in significant changes to the policy environment. This paper presents a rationale for reframing the problem of obesity as caloric overconsumption. The frame “obesity” contributes to the policy cacophony by including policies aimed at both energy output and energy input. However, research increasingly demonstrates that energy input is the primary cause of obesity, and that increases in energy input are largely attributable to the food environment. By focusing on policies that aim to prevent increases in energy input, the frame caloric overconsumption will reduce the noise of the obesity policy cacophony. While the proposed frame will face some challenges, particularly industry opposition, policies aimed at preventing caloric overconsumption have a clearer focus, and can be more politically palatable if caloric overconsumption is seen as an involuntary risk resulting from the food environment. Summary

  13. Transferencia de calor en el secado solar a la intemperie de menas lateríticas ferroniquelíferas

    OpenAIRE

    Yoalbys Retirado-Mediaceja; Marbelis Lamorú-Urgelles; Ever Góngora-Leyva; Enrique Torres-Tamayo; Benigno Leyva-de la Cruz; Daynelis García-Batista

    2011-01-01

    En Moa, las menas lateríticas son sometidas a secado solar a la intemperie para reducirles el contenido de humedad antes de incorporarlas al proceso de secado térmico convencional. Este artículo evalúa los procesos de transferencia de calor fundamentales que tienen lugar durante el secado natural con el propósito de determinar el modo predominante de transferencia de calor. En dos pilas de menas lateríticas expuestas a secado solar natural se midieron las variables climatológicas y termodinám...

  14. PREFACE: XVth International Conference on Calorimetry in High Energy Physics (CALOR2012)

    Science.gov (United States)

    Akchurin, Nural

    2012-12-01

    The XVth International Conference on Calorimetry in High Energy Physics, CALOR2012, was held in Santa Fe, New Mexico from 4-8 June 2012. The series of conferences on calorimetry started in 1990 at Fermilab, and they have been the premier event for calorimeter aficionados, a trend that CALOR2012 upheld. This year, several presentations focused on the status of the major calorimeter systems, especially at the LHC. Discussions on new and developing techniques in calorimetry took a full day. Excellent updates on uses of calorimeters or about ideas that are deeply rooted in particle physics calorimetry in astrophysics and neutrino physics were followed by talks on algorithms and special triggers that rely on calorimeters. Finally, discussions of promising current developments and ongoing R&D work for future calorimeters capped the conference. The field of calorimetry is alive and well, as evidenced by the more than 100 attendees and the excellent quality of over 80 presentations. You will find the written contributions in this volume. The presentations can be found at calor2012.ttu.edu. The first day of the conference was dedicated to the LHC. In two invited talks, Guillaume Unal (CERN) and Tommaso Tabarelli de Fatis (Universita' & INFN Milano Bicocca) discussed the critical role electromagnetic calorimeters play in the hunt for the Standard Model Higgs boson in ATLAS and CMS, respectively. The enhanced sensitivity for light Higgs in the two-gamma decay channel renders electromagnetic calorimeters indispensible. Much of the higher mass region was already excluded for the SM Higgs by the time of this conference, and after less than a month, on 4 July, CERN announced the discovery of a new boson at 125 GeV, a particle that seems consistent with the Higgs particle so far. Once again, without the electromagnetic calorimeters, this would not have been possible. Professor Geoffrey West from the Santa Fe Institute gave the keynote address. His talk, 'Universal Scaling Laws

  15. One-Year Behavioral Treatment of Obesity: Comparison of Moderate and Severe Caloric Restriction and the Effects of Weight Maintenance Therapy.

    Science.gov (United States)

    Wadden, Thomas A.; And Others

    1994-01-01

    Compared weight losses of 49 obese women assigned to 52-week behavioral program combined with moderate or severe caloric restriction. Those in severe caloric restriction group lost significantly more weight during first 26 weeks but regained some weight. Reports of binge eating declined in both groups, and no relationship was observed between…

  16. Caloric Intake from Fast Food among Children and Adolescents in the United States, 2011-2012. NCHS Data Brief. Number 213

    Science.gov (United States)

    Vikraman, Sundeep; Fryar, Cheryl D.; Ogden, Cynthia L.

    2015-01-01

    Consumption of fast food has been linked to weight gain in adults. Fast food has also been associated with higher caloric intake and poorer diet quality in children and adolescents. From 1994 through 2006, caloric intake from fast food increased from 10% to 13% among children aged 2-18 years. This report presents the most recent data on the…

  17. Caloric restriction alters the metabolic response to a mixed-meal: results from a randomized, controlled trial.

    Directory of Open Access Journals (Sweden)

    Kim M Huffman

    Full Text Available To determine if caloric restriction (CR would cause changes in plasma metabolic intermediates in response to a mixed meal, suggestive of changes in the capacity to adapt fuel oxidation to fuel availability or metabolic flexibility, and to determine how any such changes relate to insulin sensitivity (S(I.Forty-six volunteers were randomized to a weight maintenance diet (Control, 25% CR, or 12.5% CR plus 12.5% energy deficit from structured aerobic exercise (CR+EX, or a liquid calorie diet (890 kcal/d until 15% reduction in body weightfor six months. Fasting and postprandial plasma samples were obtained at baseline, three, and six months. A targeted mass spectrometry-based platform was used to measure concentrations of individual free fatty acids (FFA, amino acids (AA, and acylcarnitines (AC. S(I was measured with an intravenous glucose tolerance test.Over three and six months, there were significantly larger differences in fasting-to-postprandial (FPP concentrations of medium and long chain AC (byproducts of FA oxidation in the CR relative to Control and a tendency for the same in CR+EX (CR-3 month P = 0.02; CR-6 month P = 0.002; CR+EX-3 month P = 0.09; CR+EX-6 month P = 0.08. After three months of CR, there was a trend towards a larger difference in FPP FFA concentrations (P = 0.07; CR-3 month P = 0.08. Time-varying differences in FPP concentrations of AC and AA were independently related to time-varying S(I (P<0.05 for both.Based on changes in intermediates of FA oxidation following a food challenge, CR imparted improvements in metabolic flexibility that correlated with improvements in S(I.ClinicalTrials.gov NCT00099151.

  18. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  19. A two year randomized controlled trial of human caloric restriction: feasibility and effects on predictors of health span and longevity

    Science.gov (United States)

    Background: Caloric restriction (CR), energy intake reduced below ad libitum (AL) intake, increases life span in many species. The implications for humans can be clarified by randomized controlled trials of CR. Methods: To determine CRs feasibility, safety, and effects on predictors of longevity, di...

  20. Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

    Directory of Open Access Journals (Sweden)

    Leandro Fabrício Fiori

    2015-09-01

    Full Text Available Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet. The studied sites are located in Northwest of Paraná State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl. Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.

  1. Short-term caloric restriction normalizes hypothalamic neuronal responsiveness to glucose ingestion in patients with type 2 diabetes

    NARCIS (Netherlands)

    Teeuwisse, W.M.; Widya, R.L.; Paulides, M.; Lamb, H.J.; Smit, J.W.A.; Roos, A. de; Buchem, M.A. van; Pijl, H.; Grond, J. van der

    2012-01-01

    The hypothalamus is critically involved in the regulation of feeding. Previous studies have shown that glucose ingestion inhibits hypothalamic neuronal activity. However, this was not observed in patients with type 2 diabetes. Restoring energy balance by reducing caloric intake and losing weight are

  2. Weight loss in obese men by caloric restriction and high-dose diazoxide-mediated insulin suppression.

    NARCIS (Netherlands)

    Boekel, G.A.J van; Loves, S.; Sorge, A van; Ruinemans-Koerts, J.; Rijnders, T.; Boer, H. de

    2008-01-01

    OBJECTIVE: To examine the concept whether high-dose diazoxide (DZX)-mediated insulin suppression, in combination with moderate caloric restriction and increased physical activity, can establish a weight loss of at least 15% in obese hyperinsulinaemic men. DESIGN: Open, uncontrolled, 6-month pilot

  3. Caloric Restriction in Lean and Obese Strains of Laboratory Rat: Effects on Body Composition, Metabolism, Growth, and Overall Health

    Science.gov (United States)

    NEW FINDINGS: What is the central question of this study? How do lean and obese rats respond physiologically to caloric restriction? What is the main finding and its importance? Obese rats show marked benefits compared with lean animals. Reduced body fat is associated with improv...

  4. Tunable magneto-caloric effect in Gd1-xTbx heterostructures thin film

    Science.gov (United States)

    Lambert, C. H.; El Hadri, M. S.; Hamedoun, M.; Benyoussef, A.; Mounkachi, O.; Mangin, S.

    2017-12-01

    The magnetic and magneto-caloric properties of (Gd1-xTbx) alloy thin films and [Gd/Tb] multilayers have been investigated. All the samples had a total thickness of 100 nm and were deposited by DC sputtering. By changing the composition of the system, the ordering temperature (Tc) and the magnetic entropy changes of the compounds could be tuned. The results show that the Tc of the alloy thin films is close to 270 K for x = 0.2. Moreover, creating [Gd/Tb] multilayers with the same thickness and concentration of the studied Gd80Tb20 alloy film enables to strongly increase the relative cooling power, and reach values twice as big as from the corresponding alloys. These results suggest that nanostructuring of [Gd/Tb] multilayers may be a promising route to tailor the magnetocaloric response of materials.

  5. Assessment of potentially harmful elements pollution in the Calore River basin (Southern Italy).

    Science.gov (United States)

    Zuzolo, Daniela; Cicchella, Domenico; Catani, Vittorio; Giaccio, Lucia; Guagliardi, Ilaria; Esposito, Libera; De Vivo, Benedetto

    2017-06-01

    The geographical distribution of concentration values for harmful elements was determined in the Campania region, Italy. The study area consists of the drainage basin of the River Calore, a tributary of the river Volturno, the largest Southern Italian river. The results provide reliable analytical data allowing a quantitative assessment of the trace element pollution threat to the ecosystem and human health. Altogether 562 stream sediment samples were collected at a sampling density of 1 site per 5 km2. All samples were air-dried, sieved to urban settlements and industrial areas. The enrichment factor of these elements is 3-4 times higher than the background values. The southwestern area of the basin is characterized by a moderate/high degree of contamination, just where the two busiest roads of the area run and the highest concentration of industries occurs.

  6. Effects of Caloric Restriction on Cardiovascular Aging in Non-human Primates and Humans

    Science.gov (United States)

    Cruzen, Christina; Colman, Ricki J.

    2009-01-01

    Synopsis Approximately one in three Americans has some form of cardiovascular disease (CVD), accounting for one of every 2.8 deaths in the United States in 2004. Two of the major risk factors for CVD are advancing age and obesity. An intervention able to positively impact both aging and obesity, such as caloric restriction (CR), may prove extremely useful in the fight against CVD. CR is the only environmental or lifestyle intervention that has repeatedly been shown to increase maximum life span and to retard aging in laboratory rodents. In this article, we review evidence that CR in nonhuman primates and humans has a positive effect on risk factors for CVD. PMID:19944270

  7. Aging and Caloric Restriction Research: A Biological Perspective With Translational Potential

    Directory of Open Access Journals (Sweden)

    Priya Balasubramanian

    2017-07-01

    Full Text Available Aging as a research pursuit is fairly new compared with traditional lines of medical research. A growing field of investigators is focused on understanding how changes in tissue biology, physiology, and systemic homeostasis, conspire to create increased vulnerability to disease as a function of age. Aging research as a discipline is necessarily broad; in part because aging itself is multi-faceted and in part because different model systems are employed to define the underlying biology. In this review we outline aspects of aging research that are likely to uncover the pivotal events leading to age-related disease vulnerability. We focus on studies of human aging and discuss the value of research on caloric restriction, an intervention with proven efficacy in delaying aging. We propose that studies such as these will deliver target factors and processes that create vulnerability in human aging, an advance that would potentially be transformative in clinical care.

  8. Caloric Restriction as a Strategy to Improve Vascular Dysfunction in Metabolic Disorders

    Directory of Open Access Journals (Sweden)

    Concha F. García-Prieto

    2016-06-01

    Full Text Available Caloric restriction (CR has proved to be the most effective and reproducible dietary intervention to increase healthy lifespan and aging. A reduction in cardiovascular disease (CVD risk in obese subjects can be already achieved by a moderate and sustainable weight loss. Since pharmacological approaches for body weight reduction have, at present, a poor long-term efficacy, CR is of great interest in the prevention and/or reduction of CVD associated with obesity. Other dietary strategies changing specific macronutrients, such as altering carbohydrates, protein content or diet glycemic index have been also shown to decrease the progression of CVD in obese patients. In this review, we will focus on the positive effects and possible mechanisms of action of these strategies on vascular dysfunction.

  9. Repletion of TNFα or leptin in calorically restricted mice suppresses post-restriction hyperphagia

    Directory of Open Access Journals (Sweden)

    Catherine Hambly

    2012-01-01

    The causes of post-restriction hyperphagia (PRH represent a target for drug-based therapies to prevent obesity. However, the factors causing PRH are poorly understood. We show that, in mice, the extent of PRH was independent of the time under restriction, but depended on its severity, suggesting that PRH was driven by signals from altered body composition. Signals related to fat mass were important drivers. Circulating levels of leptin and TNFα were significantly depleted following caloric restriction (CR. We experimentally repleted their levels to match those of controls, and found that in both treatment groups the level of PRH was significantly blunted. These data establish a role for TNFα and leptin in the non-pathological regulation of energy homeostasis. Signals from adipose tissue, including but not limited to leptin and TNFα, regulate PRH and might be targets for therapies that support people engaged in CR to reduce obesity.

  10. Caloric restriction suppresses apoptotic cell death in the mammalian cochlea and leads to prevention of presbycusis.

    Science.gov (United States)

    Someya, Shinichi; Yamasoba, Tatsuya; Weindruch, Richard; Prolla, Tomas A; Tanokura, Masaru

    2007-10-01

    Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Calorie restricted (CR) mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed a significant reduction in the number of TUNEL-positive cells and cleaved caspase-3-positive cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 24 apoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR can retard this process by suppressing apoptosis in the inner ear tissue.

  11. Adiabatic measurements of magneto-caloric effects in pulsed high magnetic fields up to 55 T

    Science.gov (United States)

    Kihara, T.; Kohama, Y.; Hashimoto, Y.; Katsumoto, S.; Tokunaga, M.

    2013-07-01

    Magneto-caloric effects (MCEs) measurement system in adiabatic condition is proposed to investigate the thermodynamic properties in pulsed magnetic fields up to 55 T. With taking the advantage of the fast field-sweep rate in pulsed field, adiabatic measurements of MCEs were carried out at various temperatures. To obtain the prompt response of the thermometer in the pulsed field, a thin film thermometer is grown directly on the sample surfaces. The validity of the present setup was demonstrated in the wide temperature range through the measurements on Gd at about room temperature and on Gd3Ga5O12 at low temperatures. The both results show reasonable agreement with the data reported earlier. By comparing the MCE data with the specific heat data, we could estimate the entropy as functions of magnetic field and temperature. The results demonstrate the possibility that our approach can trace the change in transition temperature caused by the external field.

  12. Repletion of TNFα or leptin in calorically restricted mice suppresses post-restriction hyperphagia

    Science.gov (United States)

    Hambly, Catherine; Duncan, Jacqueline S.; Archer, Zoë A.; Moar, Kim M.; Mercer, Julian G.; Speakman, John R.

    2012-01-01

    SUMMARY The causes of post-restriction hyperphagia (PRH) represent a target for drug-based therapies to prevent obesity. However, the factors causing PRH are poorly understood. We show that, in mice, the extent of PRH was independent of the time under restriction, but depended on its severity, suggesting that PRH was driven by signals from altered body composition. Signals related to fat mass were important drivers. Circulating levels of leptin and TNFα were significantly depleted following caloric restriction (CR). We experimentally repleted their levels to match those of controls, and found that in both treatment groups the level of PRH was significantly blunted. These data establish a role for TNFα and leptin in the non-pathological regulation of energy homeostasis. Signals from adipose tissue, including but not limited to leptin and TNFα, regulate PRH and might be targets for therapies that support people engaged in CR to reduce obesity. PMID:21954068

  13. Neuroimaging Biomarkers of Caloric Restriction on Brain Metabolic and Vascular Functions.

    Science.gov (United States)

    Lin, Ai-Ling; Parikh, Ishita; Hoffman, Jared D; Ma, David

    2017-03-01

    Non-invasive neuroimaging methods have been developed as powerful tools for identifying in vivo brain functions for studies in humans and animals. Here we review the imaging biomarkers that are being used to determine the changes within brain metabolic and vascular functions induced by caloric restriction (CR), and their potential usefulness for future studies with dietary interventions in humans. CR causes an early shift in brain metabolism of glucose to ketone bodies, and enhances ATP production, neuronal activity and cerebral blood flow (CBF). With age, CR preserves mitochondrial activity, neurotransmission, CBF, and spatial memory. CR also reduces anxiety in aging mice. Neuroimaging studies in humans show that CR restores abnormal brain activity in the amygdala of women with obesity and enhances brain connectivity in old adults. Neuroimaging methods have excellent translational values and can be widely applied in future studies to identify dietary effects on brain functions in humans.

  14. Acute caloric restriction counteracts hepatic bile acid and cholesterol deficiency in morbid obesity.

    Science.gov (United States)

    Straniero, S; Rosqvist, F; Edholm, D; Ahlström, H; Kullberg, J; Sundbom, M; Risérus, U; Rudling, M

    2017-05-01

    Bile acid (BA) synthesis is regulated by BA signalling in the liver and by fibroblast growth factor 19 (FGF19), synthesized and released from the intestine. In morbid obesity, faecal excretion and hepatic synthesis of BAs and cholesterol are strongly induced and caloric restriction reduces their faecal excretion considerably. We hypothesized that the high intestinal food mass in morbidly obese subjects promotes faecal excretion of BAs and cholesterol, thereby creating a shortage of both BAs and cholesterol in the liver. Ten morbidly obese women (BMI 42 ± 2.6 kg m-2 ) were monitored on days 0, 3, 7, 14 and 28 after beginning a low-calorie diet (800-1100 kcal day-1 ). Serum was collected and liver size and fat content determined. Synthesis of BAs and cholesterol was evaluated from serum markers, and the serum levels of lipoproteins, BAs, proprotein convertase subtilisin/kexin type 9 (PCSK9), insulin, glucose and FGF19 were monitored. Fifty-four nonobese women (BMI cholesterol and serum levels of BAs and PCSK9 were elevated in the obese group compared to controls. Already after 3 days on a low-calorie diet, BA and cholesterol synthesis and serum BA and PCSK9 levels normalized, whereas LDL cholesterol increased. FGF19 and triglyceride levels were unchanged, and liver volume was reduced by 10%. The results suggest that hepatic BAs and cholesterol are deficient in morbid obesity. Caloric restriction rapidly counteracts these deficiencies, normalizing BA and cholesterol synthesis and circulating PCSK9 levels, indicating that overproduction of cholesterol in enlarged peripheral tissues cannot explain this phenotype. We propose that excessive food intake promotes faecal loss of BAs and cholesterol contributing to their hepatic deficiencies. © 2017 The Authors. Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine.

  15. Effects of caloric restriction on nitrogen and carbon stable isotope ratios in adult rat bone.

    Science.gov (United States)

    Robertson, Kimberly L; Rowland, Neil E; Krigbaum, John

    2014-10-15

    Stable isotope analysis is a valuable technique for dietary estimation in ecological and archaeological research, yet many variables can potentially affect tissue stable isotope signatures. Controlled feeding studies across a range of species have consistently demonstrated impacts of caloric restriction on tissue stable isotope ratios, but most have focused on juvenile, fasting, and/or starving individuals, and most have utilized soft tissues despite the importance of bone for paleodietary analyses. The goal of this study was to determine whether temporally defined, moderate food restriction could affect stable carbon and/or nitrogen isotope ratios in adult mammalian bone - a tissue that arguably reflects long-term dietary signals. Adult rats fed a standard laboratory diet were restricted to 45% of ad libitum intakes for 3 or 6 months. Relevant anatomical and physiological parameters were measured to confirm that the restriction protocol resulted in significant nutritional stress and to provide independent data to facilitate interpretation of stable isotope ratios. Femoral bone δ(13)Ccollagen, δ(15)Ncollagen, and δ(13)Capatite values were determined by isotope ratio mass spectrometry. Calorie-restricted animals exhibited a small, yet significant enrichment in (15)Ncollagen compared with control animals, reflecting protein-calorie stress. While the δ(13)Ccollagen values did not differ, the δ(13)Capatite values revealed less enrichment in (13)C than in controls, reflecting catabolism of body fat. Independent anatomical and physiological data from these same individuals support these interpretations. Results indicate that moderate caloric restriction does not appreciably undermine broad interpretations of dietary signals in adult mammalian bone. Significant variability among individuals or groups, however, is best explained by marked differences in energy intake over variable timescales. An inverse relationship between the δ(13)Capatite and δ(15)Ncollagen

  16. Caloric intake during the perioperative period and growth failure in infants with congenital heart disease.

    Science.gov (United States)

    Nicholson, George T; Clabby, Martha L; Kanter, Kirk R; Mahle, William T

    2013-02-01

    Infants with congenital heart disease have impaired weight gain during the first several months of life. Efforts have focused on improving weight gain and nutritional status during the first months of life. Close examination of the data suggests that the immediate postoperative period is problematic. Etiology of this early growth failure should be identified to develop effective interventions. This is a retrospective study of neonates who underwent modified systemic-to-pulmonary artery shunt, including Norwood palliation, at Children's Healthcare of Atlanta between January 2009 and July 2011. We analyzed growth from time of surgical intervention to hospital discharge. Measures of calculated weight-for-age Z-score (WAZ score) were performed using the World Health Organization's Anthro Software (version 3.2.2, January 2011; WHO, Geneva, Switzerland). Seventy-three patients were identified. Eight patients did not meet inclusion criteria. Complete data were collected on the remaining 65 patients. Median caloric intake patients received was 50.4 [interquartile range (IQR) 41.6 to 63.6] calories/kg/day while exclusively on parental nutrition. At hospital discharge, the median WAZ score was -2.0 (IQR -2.7 to -1.2) representing an overall median WAZ score decrease of -1.3 (IQR -1.7 to -0.7) from time of shunt palliation to hospital discharge. Despite studies showing poor weight gain in infants with congenital heart disease after neonatal palliation, this study reports the impact of hospital-based nutritional practices on weight gain in infants during the immediate postoperative period. Our data demonstrate that actual caloric intake during the cardiac intensive care unit stay is substantially below what is recommended.

  17. Effects of the dietary approaches to stop hypertension diet, exercise, and caloric restriction on neurocognition in overweight adults with high blood pressure.

    Science.gov (United States)

    Smith, Patrick J; Blumenthal, James A; Babyak, Michael A; Craighead, Linda; Welsh-Bohmer, Kathleen A; Browndyke, Jeffrey N; Strauman, Timothy A; Sherwood, Andrew

    2010-06-01

    High blood pressure increases the risks of stroke, dementia, and neurocognitive dysfunction. Although aerobic exercise and dietary modifications have been shown to reduce blood pressure, no randomized trials have examined the effects of aerobic exercise combined with dietary modification on neurocognitive functioning in individuals with high blood pressure (ie, prehypertension and stage 1 hypertension). As part of a larger investigation, 124 participants with elevated blood pressure (systolic blood pressure 130 to 159 mm Hg or diastolic blood pressure 85 to 99 mm Hg) who were sedentary and overweight or obese (body mass index: 25 to 40 kg/m(2)) were randomized to the Dietary Approaches to Stop Hypertension (DASH) diet alone, DASH combined with a behavioral weight management program including exercise and caloric restriction, or a usual diet control group. Participants completed a battery of neurocognitive tests of executive function-memory-learning and psychomotor speed at baseline and again after the 4-month intervention. Participants on the DASH diet combined with a behavioral weight management program exhibited greater improvements in executive function-memory-learning (Cohen's D=0.562; P=0.008) and psychomotor speed (Cohen's D=0.480; P=0.023), and DASH diet alone participants exhibited better psychomotor speed (Cohen's D=0.440; P=0.036) compared with the usual diet control. Neurocognitive improvements appeared to be mediated by increased aerobic fitness and weight loss. Also, participants with greater intima-medial thickness and higher systolic blood pressure showed greater improvements in executive function-memory-learning in the group on the DASH diet combined with a behavioral weight management program. In conclusion, combining aerobic exercise with the DASH diet and caloric restriction improves neurocognitive function among sedentary and overweight/obese individuals with prehypertension and hypertension.

  18. Experience with Video Head Impulse Testing (vHIT

    Directory of Open Access Journals (Sweden)

    Carmen ÁLVAREZ-SANTACRUZ

    2017-03-01

    Full Text Available Introduction and objective: The diagnosis and study of vestibular pathology has been always guided by the medical history, exploration and caloric test. The caloric test has some limitations because it only allows the study of horizontal semicircular canal and it is also poorly tolerated by patients. Alternatively, the vHIT (Video Head Impulse Test, allows the analysis of all semicircular channels being quicker to perform and less obtrusive. The objective of the following study is to reflect our initial experience with the vHIT and compare it with another diagnosis tests. Method: This is a observational, prospective and descriptive study, of one year of observation in our Healthcare center for all patients who described symptoms of dizziness, unsteadiness or vertigo. Results: A total of 155 patients were included. There was a clear predominance of females, being Meniere's disease the most frequently diagnosed entity. The diagnosis was reached by vHIT. Caloric test was also performed in patients without definite or doubt in the diagnosis. With the data, the statistical relationships were established, being significant between sex with vestibular neuritis and vestibular migraine. There was a statistically significant relationship between vestibule-ocular reflex and caloric test associated with the previous pathologies. Discussion: The head impulse assisted video is a quick, simple and well tolerated technique without adverse symptoms like the caloric test. The disparities of results are due to differences in the stimulated frequencies, being the vHIT more physiological. Conclusions: vHIT facilitates the complementary diagnosis of acute pathology, being a well-tolerated technique. However, in pathologies with central compensation the results by vHIT may be normal, requiring the caloric test for better diagnostic approach.

  19. Determinación experimental mediante DSC de las estabilidades térmicas y las capacidades caloríficas: quinua, kiwicha y cañihua

    OpenAIRE

    Romero Carrión, Violeta; Tirado Rengifo, Arminda; Dávalos Prado, Juan

    2015-01-01

    El objetivo fue determinar mediante Calorímetría diferencial de barrido (“Differential Scanning Calorimetry”, DSC) el calor específico y los parámetros termofísicos de la descomposición completa y la gelatinización, de la quinua (Chenopodium quinoa, kiwicha (Amaranthus caudatus) y la cañihua (Chenopodium pallidicaule). Para la determinación del calor específico se usaron cápsulas de aluminio y tomando de referencia el c.e del zafiro, observándose picos en el termograma, entre 50 y 60°C y calo...

  20. Looking at the label and beyond: the effects of calorie labels, health consciousness, and demographics on caloric intake in restaurants

    Science.gov (United States)

    2013-01-01

    Background Recent legislation has required calorie labels on restaurant menus as a means of improving Americans’ health. Despite the growing research in this area, no consensus has been reached on the effectiveness of menu labels. This suggests the possibility of heterogeneity in responses to caloric labels across people with different attitudes and demographics. The purpose of this study was to explore the potential relationships between caloric intake and diners’ socio-economic characteristics and attitudes in a restaurant field experiment that systematically varied the caloric information printed on the menus. Methods We conducted a field experiment in a full service restaurant where patrons were randomly assigned to one of three menu treatments which varied the amount of caloric information printed on the menus (none, numeric, or symbolic calorie label). At the conclusion of their meals, diners were asked to complete a brief survey regarding their socio-economic characteristics, attitudes, and meal selections. Using regression analysis, we estimated the number of entrée and extra calories ordered by diners as a function of demographic and attitudinal variables. Additionally, irrespective of the menu treatment to which a subject was assigned, our study identified which types of people are likely to be low-, medium-, and high-calorie diners. Results Results showed that calorie labels have the greatest impact on those who are least health conscious. Additionally, using a symbolic calorie label can further reduce the caloric intake of even the most health conscious patrons. Finally, calorie labels were more likely to influence the selection of the main entrée as opposed to supplemental items such as drinks and desserts. Conclusions If numeric calorie labels are implemented (as currently proposed), they are most likely to influence consumers who are less health conscious – probably one of the key targets of this legislation. Unfortunately, numeric labels did

  1. High Caloric Diet for ALS Patients: High Fat, High Carbohydrate or High Protein

    Directory of Open Access Journals (Sweden)

    Sarvin Sanaie

    2015-01-01

    . They showed that patients in the highcarbohydrate/high-calorie groups gained 0.39 kg more weight per month, compared with 0.11kg per month in the control group, and there was an average weight loss of 0.46 kg per month in the high-fat/high-calorie group. However, there are some concerns that highcarbohydrate low-fat diets might increase the risk of ALS and these findings should be interpreted with caution (4. Furthermore, according to Wills et al. high fat-high caloric diets could not be ideal regimens for these patients due to the associated gastrointestinal complications (3. Dorst and associates, in their study, showed that high caloric food supplement with high fat is suitable to establish body weight compared to high carbohydrate formula. Hence, it seems that high protein-high caloric diets could be more appropriate options for both improving negative nitrogen balance and decreasing muscle atrophy in patients with ALS based on the pathophysiology of proteinenergy malnutrition and hypermetabolism which is thought to be due to mitochondria problem. The multifactorial pathophysiology of ALS has resulted in hypotheses that there may be subgroups of patients, eventually defined by a specific underlying etiology or clinical presentation, which selectively respond to a particular regimen. Consequently, further RCTs with larger sample size are required to clarify the best regimen for weight gain and improved survival in ALS patients and it seems that personalized nutritional support or combined regimens might be the best way and could improve the quality of life considering the complex pathophysiology of malnutrition.

  2. Heat transfer in simple houses; Transferencia de calor en casas habitacion

    Energy Technology Data Exchange (ETDEWEB)

    Porta, Miguel Angel; Rubio, Eduardo; Fernandez, Jose Luis [Centro de Investigaciones Biologicas del Noroeste, Baja California Sur, (Mexico); Gomez Munoz, Victor [Centro Interdiciplinario de Ciencias Marinas, Baja California Sur (Mexico)

    2000-07-01

    A lumped parameter model is used to represent, with a high degree of precision, the temperature and comfort evolution with the time of a simple house, under any hot, extreme weather variation. Results are validated by experimental work in physical models, built to scale 1:2, with materials and building techniques typical of social interest housing in Baja California, Mexico. With the mathematical model properly calibrated, adequately validated heat transfer coefficients between walls, ceiling and windows are calculated. Sensitivity analyses lead to values of heat loads in simple houses with varying shapes, orientation, shading devices, and construction materials and techniques. Energy balance in the present work is achieved by means of three simultaneous equations, each depicting energy equilibrium in one of the basic building elements: the window glazing, the building materials, and inside air. Simultaneous solution of the equations is accomplished with of the Kutta method, which yields the representative temperature along the day of each of the components, while heat flow among them is calculated, together with thermal exchange with the environment. Comfort levels, energy consumption and saving are hence easily derived, and the economical pertinence of passive elements can be evaluated. [Spanish] Este trabajo presenta un modelo matematico de parametros concentrados que representa, de manera apropiada, el comportamiento de una casa habitacion tipica a lo largo de un dia cualquiera. Los resultados se validan mediante la experimentacion en modelo fisico, donde se ensayan casetas de material y dimensiones similares a las casas de interes social, a escala 1:2. Una vez que se ha calibrado el modelo, se pueden determinar, mediante corridas apropiadas en computadora, los coeficientes especificos de transferencia de calor en muros, ventanas y techo. Los analisis subsecuentes de sensibilidad producen informacion util para conocer los requerimientos energeticos de cada casa

  3. Hepatic mitochondrial energetics during catch-up fat after caloric restriction.

    Science.gov (United States)

    Crescenzo, Raffaella; Bianco, Francesca; Falcone, Italia; Prisco, Marina; Dulloo, Abdul G; Liverini, Giovanna; Iossa, Susanna

    2010-08-01

    The objective of the study was to investigate whether changes in liver mitochondrial energetics could underlie the enhanced energetic efficiency that drives accelerated body fat recovery (catch-up fat) during refeeding after caloric restriction. Rats were subjected to caloric restriction (50% of ad libitum intake) for 15 days and then refed for 1 or 2 weeks on an amount of chow equal to that of controls matched for weight at the onset of refeeding. Whole-body metabolism was characterized by energy balance and body composition determinations as well as by indirect calorimetric measurements of 24-hour energy expenditure, substrate oxidation, and whole-body de novo lipogenesis estimated from nonprotein respiratory quotient. Hepatic mitochondrial energetics were determined from measurements of liver mitochondrial mass, respiratory capacities, and proton leak (both basal and fatty acid stimulated), whereas hepatic oxidative status was assessed from measurements of hepatic mitochondrial lipid peroxidation, aconitase, and superoxide dismutase activity. Furthermore, hepatic lipogenic capacity was determined from assays of fatty acid synthase activity. Compared with controls, isocalorically refed rats showed an elevated energetic efficiency and body fat gain over both week 1 and week 2 of refeeding, as well as a lower 24-hour energy expenditure and higher rates of whole-body de novo lipogenesis at the end of both week 1 and week 2 of refeeding. Analysis of the liver revealed that after 1 week (but not after 2 weeks) of refeeding, the mitochondrial mass (but not mitochondrial density) was lower in refed rats than in controls, associated with higher state 3 mitochondrial respiratory capacity, increased superoxide dismutase activity, as well as higher fatty acid synthase activity. These results suggest that, although at the whole-body level elevations in energy efficiency and de novo lipogenesis are coordinated toward catch-up fat, the overall hepatic mitochondrial energetic

  4. Accumulation of long-chain glycosphingolipids during aging is prevented by caloric restriction.

    Directory of Open Access Journals (Sweden)

    María José Hernández-Corbacho

    Full Text Available BACKGROUND: Chronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney function declines during aging even in the absence of underlying renal disease. Declining renal function has been associated with age-related cellular damage and dysfunction with reports of increased levels of apoptosis, necrosis, and inflammation in the aged kidney. Bioactive sphingolipids have been shown to regulate these same cellular processes, and have also been suggested to play a role in aging and cellular senescence. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that alterations in kidney sphingolipids play a role in the declining kidney function that occurs during aging. To begin to address this, the sphingolipid profile was measured in young (3 mo, middle aged (9 mo and old (17 mo C57BL/6 male mice. Interestingly, while modest changes in ceramides and sphingoid bases were evident in kidneys from older mice, the most dramatic elevations were seen in long-chain hexosylceramides (HexCer and lactosylceramides (LacCer, with C14- and C16-lactosylceramides elevated as much as 8 and 12-fold, respectively. Increases in long-chain LacCers during aging are not exclusive to the kidney, as they also occur in the liver and brain. Importantly, caloric restriction, previously shown to prevent the declining kidney function seen in aging, inhibits accumulation of long-chain HexCer/LacCers and prevents the age-associated elevation of enzymes involved in their synthesis. Additionally, long-chain LacCers are also significantly elevated in human fibroblasts isolated from elderly individuals. CONCLUSION/SIGNIFICANCE: This study demonstrates accumulation of the glycosphingolipids HexCer and LacCer in several different organs in rodents and humans during aging. In addition, data demonstrate that HexCer and LacCer metabolism is regulated by caloric restriction. Taken together

  5. EFEITO DAS ONDAS DE CALOR NA AGRICULTURA – SAFRA 2013/2014

    Directory of Open Access Journals (Sweden)

    Melhores Trabalhos .

    2015-02-01

    Full Text Available Ao aquecimento global, considerado decorrência do fenômeno popularmente conhecido como efeito estufa, têm sido atribuidas muitas das anomalias climáticas que ultimamente vêm afetando  municípios, regiões, países e até continentes inteiros. Uma dessas anomalias do clima refere-se às recentes ondas de calor ocorridas no verão de 2013/2014, agora findando, registradas nas estações meteorológicas e no desconforto de pessoas, plantas e animais que habitam a região sul da América do Sul, onde estão situados o Estado do Rio Grande do Sul e, nele,  o Município de Cruz Alta. Diante do exposto, este trabalho, na forma de artigo, tem por objetivo descrever e analisar a ocorrência de alguns desastres naturais, resultantes de fenômenos meteorológicos eventuais ou recorrentemente verificados e registrados no Estado e no Município, todos quase sempre capazes de afetar seu desenvolvimento socioeconômico. Os danos anuais causados por diferentes desastres meteorológicos sobre a agricultura são calculados, em termos globais ou mundiais, na ordem de mais 41 bilhões de dólares. Ao se efetuar uma análise sobre causas e efeitos dos fenômenos meteorológicos que incidem sobre a agricultura, tendo por base parte das informações bibliográficas, documentais e midiáticas consultadas para a elaboração deste artigo, tem-se que levar em consideração que esses fenômenos manifestam-se diferenciadamente quanto à quantização de danos e percentualidade de perdas que podem ocasionar aos cultivos agrícolas. Enquanto que os prejuízos causados por granizos, geadas e secas, por exemplo, podem ser avaliados por sintomas manifestos nas plantas (quebra e ruptura de partes de hastes e colmos, necrose foliar; congelamento de tecidos e de folhas, cobertura de gelo sobre plantas e solo; e murcha de folhas, redução de crescimento, etc. e pela visualização da intensidade de ocorrência (tamanho e número de pedras de granizo, cobertura de gelo e

  6. Tolerancia al calor y humedad atmosférica de diferentes grupos raciales de ganado bovino

    Directory of Open Access Journals (Sweden)

    Ariel Guillén T

    2011-04-01

    Full Text Available Objetivo. Comparar algunas respuestas fisiológicas al calor y humedad atmosférica entre bovinos Chinampos (Bos taurus; Ch, ½ Charolais ½ Brahman (CB, Holstein (H y Jersey (J. Materiales y métodos. Se realizó un estudio en La Paz, México. Se utilizaron 12 vacas H, 10 J, 15 Ch y 8 CB. Durante el verano se midieron cada semana (a las 0600 y 1600 horas la frecuencia respiratoria (FR y temperatura rectal (TR. Se registraron las variables climáticas para calcular el índice de temperatura-humedad (ITH. Resultados. Durante todo el verano, la FR en los cuatro grupos estuvo por encima de los valores fisiológicos para el ganado bovino, siendo superior en H y J que en Ch y CB (p<0.01. En todos los grupos, la TR estuvo dentro de los límites fisiológicos de la especie estudiada. El grupo racial más afectado fue H (p<0.05. Cuando las constantes fisiológicas fueron analizadas dentro de cada una de tres categorías de ITH (<72, ≥72<78, y ≥78, las vacas H y J mostraron FR superior a las Ch y CB (p<0.01. La TR aumentó conforme se elevó el ITH siendo más marcado en J y H. El incremento de la FR entre la mañana y la tarde de cada día de medición fue mayor en H y J que en Ch y CB (p<0.05. La TR se incrementó más en H que en Ch (p<0.05. Conclusiones. Los grupos raciales más tolerantes al estrés por calor, determinado con base en FR y TR fueron Ch y CB.

  7. Study of electro-caloric effect in Ca and Sn co-doped BaTiO3 ceramics

    Science.gov (United States)

    Upadhyay, Sanjay Kumar; Fatima, Iram; Raghavendra Reddy, V.

    2017-04-01

    The present work deals with the study of structural, ferroelectric, dielectric and electro-caloric effects in lead free ferroelectric polycrystalline Ba1-x Ca x Ti0.95Sn0.05O3 (x  =  2, 5 and 10%) i.e. Ca, Sn co-doped BaTiO3 (BTO). Phase purity of the samples is confirmed from x-ray data by using Rietveld refinement. 119Sn Mössbauer reveals homogenous phase as well as iso-valent substitution of Sn at Ti site. Enhancements in ferroelectric and dielectric properties have been observed. Indirect method which is based on Maxwell equation has been used to determine the electro-caloric (EC) effect in the studied ferroelectric ceramics and maximum EC coefficient is observed for Ba0.95Ca0.05Ti0.95Sn0.05O3.

  8. Diseño experimental, construcción y calibración de un sensor de flujo de calor para aplicaciones HVAC/R

    OpenAIRE

    Fonseca Díaz, Néstor; Burbano Jaramillo, Juan Carlos

    2007-01-01

    Este artículo presenta los resultados del estudio para el diseño experimental, construcción y calibración de un sensor de flujo de calor de utilidad en la detección de flujos de calor muy pequeños en Calefacción, Ventilación, Acondicionamiento de aire y Refrigeración (HVAC/R). Se propone el diseño de un sensor para medir flujos de calor en paredes de edificios y cuartos fríos del orden de 2 a 30 W/(m2K) con una incertidumbre total máxima de 5 % del flujo de calor medido. Actualmente, para ot...

  9. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study: e0151213

    National Research Council Canada - National Science Library

    Grazia Fernanda Spitoni; Giorgio Pireddu; Gaspare Galati; Valentina Sulpizio; Stefano Paolucci; Luigi Pizzamiglio

    2016-01-01

    .... To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain...

  10. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Science.gov (United States)

    Griffioen-Roose, Sanne; Smeets, Paul A M; Weijzen, Pascalle L G; van Rijn, Inge; van den Bosch, Iris; de Graaf, Cees

    2013-01-01

    The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink) versus nutrient-rich drink (yoghurt drink) on reward value after repeated exposure. We used a randomized crossover design whereby forty subjects (15 men, 25 women) with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2) consumed a fixed portion of a non-caloric sweetened (NS) and sugar sweetened (SS) versions of either a soft drink or a yoghurt drink (counterbalanced) for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18) fMRI was performed to assess brain reward responses to the drinks. Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  11. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Directory of Open Access Journals (Sweden)

    Sanne Griffioen-Roose

    Full Text Available BACKGROUND: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. OBJECTIVE: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink versus nutrient-rich drink (yoghurt drink on reward value after repeated exposure. DESIGN: We used a randomized crossover design whereby forty subjects (15 men, 25 women with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2 consumed a fixed portion of a non-caloric sweetened (NS and sugar sweetened (SS versions of either a soft drink or a yoghurt drink (counterbalanced for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18 fMRI was performed to assess brain reward responses to the drinks. RESULTS: Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. CONCLUSION: Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  12. Caloric restriction and intermittent fasting: Two potential diets for successful brain aging

    Science.gov (United States)

    Martin, Bronwen; Mattson, Mark P.; Maudsley, Stuart

    2008-01-01

    The vulnerability of the nervous system to advancing age is all too often manifest in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. In this review article we describe evidence suggesting that two dietary interventions, caloric restriction (CR) and intermittent fasting (IF), can prolong the health-span of the nervous system by impinging upon fundamental metabolic and cellular signaling pathways that regulate life-span. CR and IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging. There are multiple interactive pathways and molecular mechanisms by which CR and IF benefit neurons including those involving insulin-like signaling, FoxO transcription factors, sirtuins and peroxisome proliferator-activated receptors. These pathways stimulate the production of protein chaperones, neurotrophic factors and antioxidant enzymes, all of which help cells cope with stress and resist disease. A better understanding of the impact of CR and IF on the aging nervous system will likely lead to novel approaches for preventing and treating neurodegenerative disorders. PMID:16899414

  13. Transport of heat in caloric vestibular stimulation. Conduction, convection or radiation?

    Science.gov (United States)

    Feldmann, H; Hüttenbrink, K B; Delank, K W

    1991-01-01

    Experiments in temporal bone specimens were carried out under strictly controlled conditions: temperature (37 degrees C) and humidity kept constant; standardized irrigation of the external ear canal by an automated system (in 15 s, 50 ml of water, 11 degrees C above temperature of specimen), thermistor probes of 0.2 mm diameter placed in different parts of the specimens. In the intact temporal bone such an irrigation causes a rise in temperature with a gradient from the external ear canal across the bony bridge to the lateral semicircular canal as expected with heat conduction. After removal of the bony bridge, which is the main route for heat conduction, the rise in temperature in the lateral semicircular canal is greater and faster than in the intact specimen. This effect again is drastically reduced by placing a reflecting shield between tympanic membrane and labyrinth. In the intact middle ear inserting a reflecting shield or filling the cavity with gel also reduces the heat transfer to the labyrinth, although the bony routes for heat conduction are left untouched. The experiments prove that radiation plays an important part in heat transfer in caloric stimulation.

  14. Caloric restriction in grouped rats: aggregate influence on behavioural and hormonal data.

    Science.gov (United States)

    Moneo, Mikel; Martín Zúñiga, Jesús; Morón, Ignacio

    2017-10-01

    The majority of studies in short- and middle-term caloric restriction (CR) have been primarily focused on physiological parameters, improvements in aging, modulation of oxidative stress, and long-term negative effects on cognitive functions. However, single-housing associated with CR may pose many logistical problems. Thus, it is necessary to study the effects of CR under conditions in which animals are group-housed. The aims of this study were to (i) observe the possible differences in the proportion of the weights and social behaviour under ad libitum and CR (at 70%) conditions; (ii) examine the eventual inequalities in the proportion of the weights and social behaviour (the time spent eating under the feeder as an indicator of dominance and empathy, and the number of 'pushes' as an indicator of aggressiveness) in sibling and non-sibling rats under CR conditions; and (iii) compare the concentrations of corticosterone (stress biomarker) in serum under ad libitum and CR conditions. The results indicated the effectiveness of CR in different groups independent of the relationship between the rats. No extreme changes in weight were observed in the CR rats. Behavioural observations also indicated the differences in the total time spent under the feeder and in the number of pushes (higher in both cases for the sibling rats). However, no significant differences in corticosterone levels were observed. Our results suggest the viability of group-housing rats during long periods of CR maintenance.

  15. Differential responses of white adipose tissue and brown adipose tissue to caloric restriction in rats.

    Science.gov (United States)

    Okita, Naoyuki; Hayashida, Yusuke; Kojima, Yumiko; Fukushima, Mayumi; Yuguchi, Keiko; Mikami, Kentaro; Yamauchi, Akiko; Watanabe, Kyoko; Noguchi, Mituru; Nakamura, Megumi; Toda, Toshifusa; Higami, Yoshikazu

    2012-05-01

    Caloric restriction (CR) slows the aging process and extends longevity, but the exact underlying mechanisms remain debatable. It has recently been suggested that the beneficial action of CR may be mediated in part by adipose tissue remodeling. Mammals have two types of adipose tissue: white adipose tissue (WAT) and brown adipose tissue (BAT). In this study, proteome analysis using two-dimensional gel electrophoresis combined with MALDI-TOF MS, and subsequent analyses were performed on both WAT and BAT from 9-month-old male rats fed ad libitum or subjected to CR for 6 months. Our findings suggest that CR activates mitochondrial energy metabolism and fatty acid biosynthesis in WAT. It is likely that in CR animals WAT functions as an energy transducer from glucose to energy-dense lipid. In contrast, in BAT CR either had no effect on, or down-regulated, the mitochondrial electron transport chain, but enhanced fatty acid biosynthesis. This suggests that in CR animals BAT may change its function from an energy consuming system to an energy reservoir system. Based on our findings, we conclude that WAT and BAT cooperate to use energy effectively via a differential response of mitochondrial function to CR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Evaluation of dysphagia risk, nutritional status and caloric intake in elderly patients with Alzheimer's

    Directory of Open Access Journals (Sweden)

    Vanessa Fernanda Goes

    2014-04-01

    Full Text Available OBJECTIVE: to evaluate the risk of dysphagia and its relationship with the stage of Alzheimer's Disease, as well as the relationship between the risk of dysphagia and nutritional status and caloric intake in elderly people with Alzheimer's disease.METHODS: the sample consisted of 30 subjects of both genders with probable Alzheimer's disease. The stage of the disease, nutritional status, energy intake, and risk of dysphagia were assessed.RESULTS: it was found that increased risk of dysphagia is associated with the advance in the stages of Alzheimer's disease and that even patients in the early stages of disease have a slight risk of developing dysphagia. No association was found between nutritional status and the risk of dysphagia. High levels of inadequate intake of micronutrients were also verified in the patients.CONCLUSION: an association between dysphagia and the development of Alzheimer's disease was found. The results indicate the need to monitor the presence of dysphagia and the micronutrient intake in patients with Alzheimer's disease.

  17. Krebs cycle enzymes from livers of old mice are differentially regulated by caloric restriction.

    Science.gov (United States)

    Hagopian, Kevork; Ramsey, Jon J; Weindruch, Richard

    2004-08-01

    Krebs cycle enzyme activities and levels of five metabolites were determined from livers of old mice (30 months) maintained either on control or on long-term caloric restriction (CR) diets (28 months). In CR mice, the cycle was divided into two major blocks, the first containing citrate synthase, aconitase and NAD-dependent isocitrate dehydrogenase which showed decreased activities, while the second block, containing the remaining enzymes, displayed increased activity (except for fumarase, which was unchanged). CR also resulted in decreased levels of citrate, glutamate and alpha-ketoglutarate, increased levels of malate, and unchanged levels of aspartate. The alpha-ketoglutarate/glutamate and malate/alpha-ketoglutarate ratios were higher in CR, in parallel with previously reported increases with CR in pyruvate carboxylase activity and glucagon levels, respectively. The results indicate that long-term CR induces a differential regulation of Krebs cycle in old mice and this regulation may be the result of changes in gene expression levels, as well as a complex interplay between enzymes, hormones and other effectors. Truncation of Krebs cycle by CR may be an important adaptation to utilize available substrates for the gluconeogenesis necessary to sustain glycolytic tissues, such as brain.

  18. Caloric restriction reveals a metabolomic and lipidomic signature in liver of male mice.

    Science.gov (United States)

    Jové, Mariona; Naudí, Alba; Ramírez-Núñez, Omar; Portero-Otín, Manuel; Selman, Colin; Withers, Dominic J; Pamplona, Reinald

    2014-10-01

    Lipid composition, particularly membrane unsaturation, has been proposed as being a lifespan determinant, but it is currently unknown whether caloric restriction (CR), an accepted life-extending intervention, affects cellular lipid profiles. In this study, we employ a liquid chromatography quadrupole time-of-flight-based methodology to demonstrate that CR in the liver of male C57BL/6 mice: (i) induces marked changes in the cellular lipidome, (ii) specifically reduces levels of a phospholipid peroxidation product, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphatidylcholine, (iii) alters cellular phosphoethanolamine and triglyceride distributional profiles, (iv) affects mitochondrial electron transport chain complexes, increasing complex II and decreasing complex III and (v) is associated with specific changes in liver metabolic pathways. These data demonstrate that CR induces a specific lipidome and metabolome reprogramming event in mouse liver which is associated with lower protein oxidative damage, as assessed by mass spectrometry-based measurements. Such changes may be critical to the increased lifespan and healthspan observed in C57BL/6 mice following CR. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  19. Caloric restriction improves efficiency and capacity of the mitochondrial electron transport chain in Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Choi, Kyung-Mi [College of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr [College of Life Sciences and Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of)

    2011-06-03

    Highlights: {yields} Calorie restriction (CR) increases electron transport chain (ETC) at both RNA and protein level. {yields} CR enhances mitochondrial membrane potential, and, regardless of ages, reduces reactive oxygen species. {yields} CR increases both efficiency and capacity of the ETC. {yields} CR induces intensive modulation at mitochondrial ETC where might be a major site leading to extension of lifespan. -- Abstract: Caloric restriction (CR) is known to extend lifespan in a variety of species; however, the mechanism remains unclear. In this study, we found that CR potentiated the mitochondrial electron transport chain (ETC) at both the transcriptional and translational levels. Indeed, mitochondrial membrane potential (MMP) was increased by CR, and, regardless of ages, overall reactive oxygen species (ROS) generation was decreased by CR. With these changes, overall growth rate of cells was maintained under various CR conditions, just like cells under a non-restricted condition. All of these data support increased efficiency and capacity of the ETC by CR, and this change might lead to extension of lifespan.

  20. Maintenance of cellular ATP level by caloric restriction correlates chronological survival of budding yeast

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon-Seok; Lee, Cheol-Koo, E-mail: cklee2005@korea.ac.kr

    2013-09-13

    Highlights: •CR decreases total ROS and mitochondrial superoxide during the chronological aging. •CR does not affect the levels of oxidative damage on protein and DNA. •CR contributes extension of chronological lifespan by maintenance of ATP level -- Abstract: The free radical theory of aging emphasizes cumulative oxidative damage in the genome and intracellular proteins due to reactive oxygen species (ROS), which is a major cause for aging. Caloric restriction (CR) has been known as a representative treatment that prevents aging; however, its mechanism of action remains elusive. Here, we show that CR extends the chronological lifespan (CLS) of budding yeast by maintaining cellular energy levels. CR reduced the generation of total ROS and mitochondrial superoxide; however, CR did not reduce the oxidative damage in proteins and DNA. Subsequently, calorie-restricted yeast had higher mitochondrial membrane potential (MMP), and it sustained consistent ATP levels during the process of chronological aging. Our results suggest that CR extends the survival of the chronologically aged cells by improving the efficiency of energy metabolism for the maintenance of the ATP level rather than reducing the global oxidative damage of proteins and DNA.

  1. Caloric Restriction Protects against Lactacystin-Induced Degeneration of Dopamine Neurons Independent of the Ghrelin Receptor

    Directory of Open Access Journals (Sweden)

    Jessica Coppens

    2017-03-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder, characterized by a loss of dopamine (DA neurons in the substantia nigra pars compacta (SNc. Caloric restriction (CR has been shown to exert ghrelin-dependent neuroprotective effects in the 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP-based animal model for PD. We here investigated whether CR is neuroprotective in the lactacystin (LAC mouse model for PD, in which proteasome disruption leads to the destruction of the DA neurons of the SNc, and whether this effect is mediated via the ghrelin receptor. Adult male ghrelin receptor wildtype (WT and knockout (KO mice were maintained on an ad libitum (AL diet or on a 30% CR regimen. After 3 weeks, LAC was injected unilaterally into the SNc, and the degree of DA neuron degeneration was evaluated 1 week later. In AL mice, LAC injection significanty reduced the number of DA neurons and striatal DA concentrations. CR protected against DA neuron degeneration following LAC injection. However, no differences were observed between ghrelin receptor WT and KO mice. These results indicate that CR can protect the nigral DA neurons from toxicity related to proteasome disruption; however, the ghrelin receptor is not involved in this effect.

  2. Transferencia de calor en la colada continua de aceros. II parte. Enfriamiento secundario

    Directory of Open Access Journals (Sweden)

    Cicutti, C.

    1997-12-01

    Full Text Available Once the strand leaves the mold, the solidification of steel progresses due to the heat extracted in the secondary cooling zone of the continuous casting machine. In this zone, heat is extracted mainly by: the incidence of water from sprays, radiation to surroundings contact with rolls and run out water accumulated between rolls and strand. In this work, all these mechanisms are evaluated and, when it is possible, they are quantified. Methods which are usually employed to measure solidification profiles in the continuous casting machine are also reviewed. Finally, the incidence of secondary cooling on the quality of cast products is discussed.

    La solidificación del acero iniciada en el molde continúa en la zona de enfriamiento secundario de la máquina donde el calor es extraído, principalmente por la incidencia del agua de los rociadores, la radiación al medio ambiente, el contacto con los rodillos y el agua acumulada en ellos. En este trabajo se revisa cada uno de estos mecanismos determinando, en los casos en que es posible, valores cuantitativos de los mismos. Además, se analizan los distintos métodos empleados para medir el avance del espesor solidificado en la máquina de colada continua. Por último, se discute la incidencia del enfriamiento secundario en la calidad final de los productos colados.

  3. Effects of Low-Dose Non-Caloric Sweetener Consumption on Gut Microbiota in Mice

    Directory of Open Access Journals (Sweden)

    Takashi Uebanso

    2017-06-01

    Full Text Available Abstract: Non-caloric artificial sweeteners (NASs provide sweet tastes to food without adding calories or glucose. NASs can be used as alternative sweeteners for controlling blood glucose levels and weight gain. Although the consumption of NASs has increased over the past decade in Japan and other countries, whether these sweeteners affect the composition of the gut microbiome is unclear. In the present study, we examined the effects of sucralose or acesulfame-K ingestion (at most the maximum acceptable daily intake (ADI levels, 15 mg/kg body weight on the gut microbiome in mice. Consumption of sucralose, but not acesulfame-K, for 8 weeks reduced the relative amount of Clostridium cluster XIVa in feces. Meanwhile, sucralose and acesulfame-K did not increase food intake, body weight gain or liver weight, or fat in the epididymis or cecum. Only sucralose intake increased the concentration of hepatic cholesterol and cholic acid. Moreover, the relative concentration of butyrate and the ratio of secondary/primary bile acids in luminal metabolites increased with sucralose consumption in a dose-dependent manner. These results suggest that daily intake of maximum ADI levels of sucralose, but not acesulfame-K, affected the relative amount of the Clostridium cluster XIVa in fecal microbiome and cholesterol bile acid metabolism in mice.

  4. Caloric restriction preserves memory and reduces anxiety of aging mice with early enhancement of neurovascular functions.

    Science.gov (United States)

    Parikh, Ishita; Guo, Janet; Chuang, Kai-Hsiang; Zhong, Yu; Rempe, Ralf G; Hoffman, Jared D; Armstrong, Rachel; Bauer, Björn; Hartz, Anika M S; Lin, Ai-Ling

    2016-11-08

    Neurovascular integrity plays an important role in protecting cognitive and mental health in aging. Lifestyle interventions that sustain neurovascular integrity may thus be critical on preserving brain functions in aging and reducing the risk for age-related neurodegenerative disorders. Here we show that caloric restriction (CR) had an early effect on neurovascular enhancements, and played a critical role in preserving vascular, cognitive and mental health in aging. In particular, we found that CR significantly enhanced cerebral blood flow (CBF) and blood-brain barrier function in young mice at 5-6 months of age. The neurovascular enhancements were associated with reduced mammalian target of rapamycin expression, elevated endothelial nitric oxide synthase signaling, and increased ketone bodies utilization. With age, CR decelerated the rate of decline in CBF. The preserved CBF in hippocampus and frontal cortex were highly correlated with preserved memory and learning, and reduced anxiety, of the aging mice treated with CR (18-20 months of age). Our results suggest that dietary intervention started in the early stage (e.g., young adults) may benefit cognitive and mental reserve in aging. Understanding nutritional effects on neurovascular functions may have profound implications in human brain aging and age-related neurodegenerative disorders.

  5. Effects of Caloric Restriction on Age-Related Hearing Loss in Rodents and Rhesus Monkeys

    Science.gov (United States)

    Someya, Shinichi; Tanokura, Masaru; Weindruch, Richard; Prolla, Tomas A.; Yamasoba, Tatsuya

    2014-01-01

    Age-related hearing loss (AHL), also known as presbycusis, is a universal feature of mammalian aging and is the most frequently occurring sensory disorder in the elderly population. AHL is characterized by a decline of auditory function and loss of hair cells and spiral ganglion neurons in the cochlea of the inner ear. It has been postulated that AHL occurs gradually as a result of the cumulative effect with aging of exposure to noise, diet, oxidative damage, and mitochondrial DNA mutations. However, the molecular mechanisms of AHL remain unclear and no preventative or therapeutic interventions have been developed. A growing body of evidence suggests increased oxidative damage with aging to macromolecules such as DNA, proteins, and lipids may play a causal role in aging and age-related diseases. Caloric restriction (CR) extends the lifespan of most mammalian species, delays the onset of multiple age-related diseases, and attenuates both the degree of oxidative damage and the associated decline in physiological function. Here, we review studies on CR’s ability to prevent cochlear pathology and AHL in laboratory animals and discuss potential molecular mechanisms of CR’s actions. PMID:20298166

  6. Entropy Generation and Human Aging: Lifespan Entropy and Effect of Diet Composition and Caloric Restriction Diets

    Directory of Open Access Journals (Sweden)

    Carlos A. Silva

    2009-01-01

    Full Text Available The first and second laws of thermodynamic were applied to statistical databases on nutrition and human growth in order to estimate the entropy generation over the human lifespan. The calculations were performed for the cases of variation in the diet composition and calorie restriction diets; and results were compared to a base case in which lifespan entropy generation was found to be 11 404 kJ/K per kg of body mass, predicting a lifespan of 73.78 and 81.61 years for the average male and female individuals respectively. From the analysis of the results, it was found that changes of diet % of fat and carbohydrates do not have a significant impact on predicted lifespan, while the diet % of proteins has an important effect. Reduction of diet protein % to the minimum recommended in nutrition literature yields an average increase of 3.3 years on the predicted lifespan. Changes in the calorie content of the diet also have an important effect, yielding a % increase in lifespan equal or higher than the % reduction in the diet caloric content. This correlates well experimental data on small mammal and insects, in which lifespan has been increased by diet restriction.

  7. Attentional biases to foods: The effects of caloric content and cognitive restraint.

    Science.gov (United States)

    Forestell, Catherine A; Lau, Pia; Gyurovski, Ivo I; Dickter, Cheryl L; Haque, Sabrina S

    2012-12-01

    The goal of the present study was to determine whether female restrained and unrestrained eaters demonstrated differential levels of attentional bias to high calorie foods when they were presented as distractors in a flanker task. This task consisted of four blocks of 68 trials in which three food pictures were briefly presented simultaneously on a computer screen. On each trial a high or low calorie target food was presented in the center of a pair of high or low calorie food flanker pictures and participants' reaction times to answer a basic question about whether they would consume the target food for breakfast were recorded. In Experiment 1, in which all participants were fed a snack prior to engaging in the flanker task, there was no evidence that restrained (n=29) or unrestrained (n=37) eaters had an attentional bias. However, in Experiment 2, when participants completed the flanker task while hungry, restrained eaters (n=27) experienced response conflict only when low calorie targets were flanked by high calorie distractors, whereas unrestrained eaters (n=46) were distracted by high calorie flankers regardless of the caloric content of the target cue. The results from this implicit task indicate that flankers interfere with hungry participants' responses to varying degrees depending on their cognitive restraint. Whether attentional bias to food cues subsequently affects food choices and eating behavior is a topic for further investigation. Published by Elsevier Ltd.

  8. Historical evolution of slope instability in the Calore River Basin, Southern Italy

    Science.gov (United States)

    Diodato, Nazzareno; Soriano, Marcella; Bellocchi, Gianni; Fiorillo, Francesco; Cevasco, Andrea; Revellino, Paola; Guadagno, Francesco Maria

    2017-04-01

    There is interest in knowing historical spatio-temporal patterns of landslide activity. However, this is challenging to reconstruct because it is difficult to obtain detailed records for past landslide activity. Here, we deal with hydro-geomorphological signatures, such as storms, downpours, floods, snowmelt and mass movement, to detect annual slope instability events (ASIEs) over historical times. In order to obtain ASIEs for each year, a monthly Instability Density Index (IDI) was used and then monthly values were summed up to obtain a yearly value. Classes of monthly IDI varying between 0 (no instability) and 4 (highest instability) were determined from historical documents. We present an application for the Calore River Basin, Southern Italy, using data from a 313-year long series (1701-2013 CE). After 1880 CE the information becomes more valuable with directly observed landslide frequency. By this cataloguing, 129 ASIEs were obtained. Their evolution shows slight instability during the 18th century. Uneven and greater slope instability occurred instead across the 19th century, when an important phase of deforestation coincided with intensification of agricultural activities. Slope instability events continued during the 20th century but their causes are mainly related to anthropisation and the effects of recent climate change. It was determined that stormy autumns until the 19th century and successive winter-times with enhanced snowmelt, may have driven the reactivation of widespread instability events. We also found that mountainous and hilly terrains have an acute sensitivity to climate change.

  9. Adipose-immune interactions during obesity and caloric restriction: reciprocal mechanisms regulating immunity and health span.

    Science.gov (United States)

    Dixit, Vishwa Deep

    2008-10-01

    Increasing evidence suggests a tight coupling of metabolic and immune systems. This cross-talk mediated by neuroendocrine peptides as well as numerous cytokines and chemokines is believed to be responsible for integrating energy balance to immune function. These neuroendocrine-immune interactions are heightened during the state of chronic positive energy balance, as seen during obesity, and negative energy balance caused by caloric restriction (CR). Emerging evidence suggests that obesity may be associated with an immunodeficient state and chronic inflammation, which contribute to an increased risk of premature death. The direct interactions between expanded leukocyte populations within the adipose tissue during obesity and an increased number of adipocytes within an aging lymphoid microenvironment may constitute an important adaptive or pathological response as a result of change in energy balance. In stark contrast to obesity, CR causes negative energy balance and robustly prolongs a healthy lifespan in all of the species studied to date. Therefore, the endogenous neuroendocrine-metabolic sensors elevated or suppressed as a result of changes in energy balance may offer an important mechanism in understanding the antiaging and potential immune-enhancing nature of CR. Ghrelin, one such sensor of negative energy balance, is reduced during obesity and increased by CR. Ghrelin also regulates immune function by reducing proinflammatory cytokines and promotes thymopoiesis during aging and thus, may be a new CR mimetic target. The identification of immune effects and molecular pathways used by such orexigenic metabolic factors could offer potentially novel approaches to enhance immunity and increase healthy lifespan.

  10. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities.

    Science.gov (United States)

    Smith, William R; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-21

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for c P , one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH 3 CH(OH)CH 3 , and for the more complex molecule monoethanolamine, HO(CH 2 ) 2 NH 2 , an important fluid used in carbon capture.

  11. Molecular simulation of caloric properties of fluids modelled by force fields with intramolecular contributions: Application to heat capacities

    Science.gov (United States)

    Smith, William R.; Jirsák, Jan; Nezbeda, Ivo; Qi, Weikai

    2017-07-01

    The calculation of caloric properties such as heat capacity, Joule-Thomson coefficients, and the speed of sound by classical force-field-based molecular simulation methodology has received scant attention in the literature, particularly for systems composed of complex molecules whose force fields (FFs) are characterized by a combination of intramolecular and intermolecular terms. The calculation of a thermodynamic property for a system whose molecules are described by such a FF involves the calculation of the residual property prior to its addition to the corresponding ideal-gas property, the latter of which is separately calculated, either using thermochemical compilations or nowadays accurate quantum mechanical calculations. Although the simulation of a volumetric residual property proceeds by simply replacing the intermolecular FF in the rigid molecule case by the total (intramolecular plus intermolecular) FF, this is not the case for a caloric property. We describe the correct methodology required to perform such calculations and illustrate it in this paper for the case of the internal energy and the enthalpy and their corresponding molar heat capacities. We provide numerical results for cP, one of the most important caloric properties. We also consider approximations to the correct calculation procedure previously used in the literature and illustrate their consequences for the examples of the relatively simple molecule 2-propanol, CH3CH(OH)CH3, and for the more complex molecule monoethanolamine, HO(CH2)2NH2, an important fluid used in carbon capture.

  12. Trombose induzida pelo calor endovenoso: relato de dois casos tratados com rivaroxabana e revisão da literatura

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    Walter Junior Boim de Araujo

    2016-01-01

    Full Text Available Resumo Define-se trombose induzida pelo calor endovenoso como a propagação do trombo a partir de uma veia superficial em direção a uma veia mais profunda. Em geral, é considerada clinicamente insignificante quando não há propagação do trombo para o sistema venoso profundo. Essa condição pode ser tratada com terapia anticoagulante, embora a observação pareça ser suficiente, principalmente para graus menores. Neste estudo, relatamos dois casos de trombose induzida pelo calor endovenoso que teriam indicação de heparina de baixo peso molecular até a resolução do quadro. Porém, optou-se pelo uso da rivaroxabana (15 mg de 12 em 12h, com resolução completa do trombo em 4 semanas (caso 1 e em 7 dias (caso 2. A rivaroxabana pode ser uma alternativa promissora no tratamento da trombose induzida pelo calor endovenoso avançada, pela simplicidade da posologia, sem comprometimento da eficácia ou da segurança. São necessários estudos prospectivos, randomizados e controlados que possibilitem melhor entendimento da condição e o desenvolvimento de recomendações mais definitivas sobre opções de prevenção e tratamento.

  13. Islas de calor urbano en Tampico, México. Impacto del microclima a la calidad del hábitat

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    Carlos Alberto Fuentes Pérez

    2014-01-01

    Full Text Available De todas las modificaciones climáticas por causa urbana, las térmicas son las más conocidas por los propios ciudadanos. La acción transformadora del espacio natural sobre el que se realiza el emplazamiento de la ciudad, llega a ser productora en gran medida de sus condiciones ambientales, incluida la climatología urbana. Todo proceso de urbanización sustituye los suelos y áreas naturales por superficies construidas, cuyos materiales se caracterizan por una baja reflectividad, con disminución de la capacidad de absorción de agua y un comportamiento térmico propicio para el almacenamiento y la emisión de calor. Estos elementos coadyuvan a realzar la temperatura atmosférica de la ciudad en relación con su entorno menos urbanizado a través de un fenómeno conocido como efecto de islas de calor urbano, produciendo un impacto del microclima a la calidad del hábitat. La presente investigación experimental aplicada tiene como objetivo, demostrar la metodología de investigación adoptada, para realizar las islas de calor urbanas en Tampico, México.

  14. Extension of Drosophila Lifespan by Rhodiola rosea Depends on Dietary Carbohydrate and Caloric Content in a Simplified Diet.

    Science.gov (United States)

    Schriner, Samuel E; Coskun, Volkan; Hogan, Sean P; Nguyen, Cindy T; Lopez, Terry E; Jafari, Mahtab

    2016-03-01

    The root and rhizome extract of Rhodiola rosea has been extensively used in traditional medicine to improve physical and mental performance and to protect against stress. We, and others, have reported that R. rosea can extend lifespan in flies, worms, and yeast. We also previously found that the extract can act independently of dietary restriction (DR), a treatment that can extend lifespan in a range of model organisms. In flies, DR is implemented through a reduction in dietary yeast content. Here, we report that the ability of R. rosea extract to extend lifespan in flies is dependent on the carbohydrate and caloric content when supplemented with a simplified diet composed of yeast and sucrose. R. rosea extract elevated the sugar content in flies and down-regulated hexokinase expression, suggesting that it perturbs carbohydrate metabolism in flies. In our previous studies, bananas, barley malt, and corn syrup provided dietary carbohydrates, and R. rosea extract could extend lifespan with a range of caloric levels. We conclude that the lifespan-extending effect of R. rosea extract in flies is dependent on dietary carbohydrate and caloric contents coupled with an interaction with complex dietary components present in bananas, barley, or corn.

  15. PROCEDIMIENTO DE CALIBRACIÓN EN TEMPERATURA Y FLUJO DE CALOR DE UN CALORÍMETRO DIFERENCIAL DE BARRIDO (DSC

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    Pablo E. Reynoso

    2016-01-01

    Full Text Available El calorímetro diferencial de barrido no es un dispositivo de medición absoluta, por lo que su utilización requiere indispensable mente una calibración. En esta contribución se presenta un procedimiento de calibración para el cual s e consideraron las temperaturas y calores de fusión aceptados en la literatura de 5 materiales puros . S e prepararon 6 muestras de dife rentes masas para cada material y s e sometió cada una de ellas a ci clos de calentamiento , desde temperatura ambiente hasta 50 ºC por encima de las temperaturas de fusión , utilizando 6 velocidades distintas por cada probeta. Luego, p ara determinar una relación de ajuste entre los datos experimentales obtenidos y los valores aceptados , se utilizó un método de regresión no lineal mediante un procedimiento matricial desarrollado en el entorno MATLAB . Los resultados obtenidos muestran una corrección con una desviación estándar de 1,2 ºC para el ajuste en temperatura y 2,1 5 J/g para el flujo de calor.

  16. [Index of Nutritional Purchasing Power Parity: comparison of caloric costs of a healthy versus an unhealthy diet].

    Science.gov (United States)

    Mendoza Velázquez, Alfonso

    2012-01-01

    Develop the Index of Nutritional Purchasing Power Parity (Nut3-CiO) as an instrument to compare the caloric costs of a healthy versus an unhealthy diet between regions or cities in a country over time. Indices of caloric prices were constructed and the "law of one price" was used to derive the Nut3-CiO index. Caloric inflation rates were obtained using basic descriptive statistics. The Nut3-CiO was applied in the major cities of Mexico during the period from January 1996 to December 2010. The statistical behavior of the Nut3-CiO revealed that, in Mexican cities, products for a typical diet are less expensive than products for a healthy diet. The findings showed a cyclical behavior to the index, a high correlation between inflation for the typical diet and inflation for the market basket, and a high persistence of prices. The Nut3-CiO index makes it possible to periodically compare the price differential of two types of diets-typical and healthy-between cities in a single country. This instrument could help health authorities identify the cities where it is easier or more difficult for consumers to access a typical or healthy diet in terms of cost. Furthermore, it makes it possible to estimate the percentage adjustment necessary in each city to attain levels of nutritional purchasing power parity.

  17. Neuroimaging to detect cortical projection of vestibular response to caloric stimulation in young and older adults using functional near-infrared spectroscopy (fNIRS).

    Science.gov (United States)

    Karim, H T; Fuhrman, S I; Furman, J M; Huppert, T J

    2013-08-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive and portable neuroimaging technique. The method uses non-ionizing laser light in the range of red to near-infrared to detect changes in cerebral blood oxygenation. In this study, we used fNIRS to investigate cortical hemodynamic changes in the temporo-parietal and frontal regions during caloric vestibular stimulation. Caloric stimulation has previously been investigated using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which serves as a validation of the fNIRS imaging modality toward the measurement of vestibular related brain regions. To date, only a single study has used fNIRS during caloric irrigations, which observed blood volume changes in the temporal-parietal area in healthy younger subjects. In this current study, fNIRS was used to measure cortical vestibular activation in 10 right-handed younger subjects (5 male and 5 female, age 25+/-6 years) and 10 right-handed older subjects (6 male and 4 female, age 74+/-5 years). We investigated both warm (44 °C) and cool (30 °C) unilateral caloric vestibular stimulation. Consistent with previous reports, we found that warm (44 °C) caloric irrigation caused a bilateral activation. In addition, we found that cool (30 °C) caloric irrigation caused contralateral activation of the temporo-parietal area. This study is the first to investigate age effects of the caloric stimulation on brain activity. We found that the older subjects had stronger bilateral effects than the younger subjects. Our results confirm previous fMRI and PET studies that showed cortical activation during caloric vestibular irrigation is dependent on side of irrigation, and temperature of irrigation. Furthermore, our results demonstrate that fNIRS is a viable technique in measuring cortical effects during vestibular tasks. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Serum concentrations and gene expression of sirtuin 1 in healthy and slightly overweight subjects after caloric restriction or resveratrol supplementation: A randomized trial.

    Science.gov (United States)

    Mansur, Antonio P; Roggerio, Alessandra; Goes, Marisa F S; Avakian, Solange D; Leal, Dalila P; Maranhão, Raul C; Strunz, Célia M C

    2017-01-15

    Sirtuin 1 (Sirt1) plays an important role in vascular biology, and influences aspects of age-dependent atherosclerosis. In animals, the sirtuin system is strongly influenced by resveratrol and caloric restriction, but its expression in humans is controversial. This study investigated the effects of resveratrol and caloric restriction on Sirt1 serum concentrations and vascular biomarkers in a healthy human population. Forty-eight healthy participants (24 women) aged 55-65years were randomized to either 30days of resveratrol administration (500mg/day) or caloric restriction (1000cal/day). Blood was collected at baseline and day 30. Laboratory data analyzed were triglycerides, total cholesterol, HDL, VLDL, LDL, apolipoprotein A1, apolipoprotein B, lipoprotein (a), non-esterified fatty acids (NEFA), glucose, insulin, oxidative stress, C-reactive protein, and Sirt1. Expression of the Sirt1 gene was analyzed using real-time PCR. Caloric restriction diminished the abdominal circumference and improved the lipid profile, but not resveratrol intervention. Resveratrol and caloric restriction increased serum concentrations of Sirt1, from 1.06±0.71 to 5.75±2.98ng/mL; presveratrol treatment. Caloric restriction and resveratrol significantly increased plasma concentrations of Sirt1. The long-term impact of these interventions on atherosclerosis should be assessed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. The role of a pre-load beverage on gastric volume and food intake: comparison between non-caloric carbonated and non-carbonated beverage.

    Science.gov (United States)

    Cuomo, Rosario; Savarese, Maria Flavia; Sarnelli, Giovanni; Nicolai, Emanuele; Aragri, Adriana; Cirillo, Carla; Vozzella, Letizia; Zito, Francesco Paolo; Verlezza, Viviana; Efficie, Eleonora; Buyckx, Maxime

    2011-10-14

    There is conflicting data on the effects of carbon dioxide contained in beverages on stomach functions. We aimed to verify the effect of a pre-meal administration of a 300 ml non-caloric carbonated beverage (B+CO2) compared to water or a beverage without CO2 (B-CO2), during a solid (SM) and a liquid meal (LM) on: a) gastric volume, b) caloric intake, c) ghrelin and cholecystokinin (CCK) release in healthy subjects. After drinking the beverages (Water, B-CO2, B+CO2), ten healthy subjects (4 women, aged 22-30 years; BMI 23 ± 1) were asked to consume either an SM or an LM, at a constant rate (110 kcal/5 min). Total gastric volumes (TGV) were evaluated by Magnetic Resonance Imaging after drinking the beverage and at maximum satiety (MS). Total kcal intake at MS was evaluated. Ghrelin and CCK were measured by enzyme immunoassay until 120 min after the meal. Statistical calculations were carried out by paired T-test and analysis of variance (ANOVA). The data is expressed as mean ± SEM. TGV after B+CO2 consumption was significantly higher than after B-CO2 or water (p < 0.05), but at MS, it was no different either during the SM or the LM. Total kcal intake did not differ at MS after any of the beverages tested, with either the SM (Water: 783 ± 77 kcals; B-CO2: 837 ± 66; B+CO2: 774 ± 66) or the LM (630 ± 111; 585 ± 88; 588 ± 95). Area under curve of ghrelin was significantly (p < 0.05) lower (13.8 ± 3.3 ng/ml/min) during SM following B-CO2 compared to B+CO2 and water (26.2 ± 4.5; 27.1 ± 5.1). No significant differences were found for ghrelin during LM, and for CCK during both SM and LM after all beverages. The increase in gastric volume following a 300 ml pre-meal carbonated beverage did not affect food intake whether a solid or liquid meal was given. The consistency of the meal and the carbonated beverage seemed to influence ghrelin release, but were unable, under our experimental conditions, to modify food intake in terms of quantity. Further studies are needed

  20. Meals of differing caloric content do not alter physical activity behavior during a subsequent simulated recess period in children.

    Science.gov (United States)

    Smith, Kelly J; Pohle-Krauza, Rachael; Uhas, Samantha; Barkley, Jacob E

    2016-01-01

    Research on adults and animals has demonstrated that chronic and acute overfeeding can alter physical activity behavior. However, there are no assessments of the acute effects of high-calorie (HC) meals on physical activity behavior in children. This is of importance as a typical school lunch is HC. If this type of meal negatively impacts subsequent physical activity behavior, the ability of post-lunch recess periods as a means to increase energy expenditure may be lessened. To assess the effect of two meals of differing caloric content, HC and low calorie (LC), on children's subsequent physical activity behavior. Nineteen healthy children (aged 6-10) completed two laboratory sessions where they were fed lunch with HC or LC content, but equivalent macronutrient distribution. Children had 15 min to consume as much of the meal as possible per session. Children consumed 659.5 ± 101.3 kcal in the HC condition and 291.8 ± 12.1 kcal in the LC condition. After the meal, children went to a gymnasium for 40 min. In the gymnasium children had free-choice access to obstacle courses, various sports equipment, and a table with sedentary activities. Children could play with any of the activities in any amount they wished for the entire activity session. Children's physical activity was monitored with accelerometers and that data was converted into caloric expenditure. Each child ate all meals and participated in the free-choice activity sessions with no other children present. Caloric expenditure during the free-choice activity sessions was not significantly different (p = 0.4) between the HC (89.2 ± 27.3 kcals) and LC (83.4 ± 34.9 kcals) conditions. However, caloric balance (kcals eaten-kcals expended) was 2.74-fold greater (p < 0.001) in the HC condition (Δ 570.3 ± 92.2 kcals) than the LC condition (Δ 208.4 ± 32.0 kcals). Children did not alter their physical activity behavior during a free-choice activity session after consuming a HC meal

  1. PREFACE: 16th International Conference on Calorimetry in High Energy Physics (CALOR 2014)

    Science.gov (United States)

    Novotny, Rainer W.

    2015-02-01

    The XVIth International Conference on Calorimetry in High Energy Physics - CALOR 2014 - was held in Giessen, Germany from 6-11 April 2014 at the Science Campus of the University. It was hosted by the Justus-Liebig-University and the HIC for FAIR Helmholtz International Center. The series of conferences on calorimetry were started in 1990 at Fermilab and are focusing primarily on operating and future calorimeter systems within the Hadron and High-Energy Physics community without neglecting the impact on other fields such as Astrophysics or Medical Imaging. Confirmed by the impressive list of over 70 oral presentations, 5 posters and over 100 attendees, the field of calorimetry appears alive and attractive. The present volume contains the written contributions of almost all presentations which can be found at http://calor2014.de. Time slots of 15 or 30 minutes including discussion were allocated. The conference was accompanied by a small exhibition of several industrial companies related to the field. The day before the opening of the scientific program, Richard Wigmans gave an excellent and vivid tutorial on basic aspects on calorimetry meant as an introduction for students and conference attendees new in the field. The opening ceremony was used to give an impression of the present and future status and the scientific program of the new FAIR facility nearby at Darmstadt presented by Klaus Peters from GSI. The conference program of the first day was dedicated to the performance and required future upgrade of the LHC experiments, dominated by ATLAS, CMS and LHCb. The program of the next day contained specific aspects on electronics and readout as well as calorimetry in outer space. Several contributions discussed in detail new concepts for hadron calorimeters within the CALICE collaboration completed by a session on sampling calorimeters. The next sections were dedicated to operating and future calorimeters at various laboratories and covering a wide range of

  2. Effect of exercise on the caloric intake of breast cancer patients undergoing treatment

    Directory of Open Access Journals (Sweden)

    C.L. Battaglini

    2008-08-01

    Full Text Available The purpose of this study was to examine the effects of an exercise intervention on the total caloric intake (TCI of breast cancer patients undergoing treatment. A secondary purpose was to determine whether or not a relationship existed between changes in TCI, body fat composition (%BF, and fatigue during the study, which lasted 6 months. Twenty females recently diagnosed with breast cancer, scheduled to undergo chemotherapy or radiation, were assigned randomly to an experimental (N = 10 or control group (N = 10. Outcome measures included TCI (3-day food diary, %BF (skinfolds, and fatigue (revised Piper Fatigue Scale. Each exercise session was conducted as follows: initial cardiovascular activity (6-12 min, followed by stretching (5-10 min, resistance training (15-30 min, and a cool-down (approximately 8 min. Significant changes in TCI were observed among groups (F1,18 = 8.582; P = 0.009, at treatments 2 and 3, and at the end of the study [experimental (1973 ± 419, control (1488 ± 418; experimental (1946 ± 437, control (1436 ± 429; experimental (2315 ± 455, control (1474 ± 294, respectively]. A significant negative correlation was found (Spearman rho(18 = -0.759; P < 0.001 between TCI and %BF and between TCI and fatigue levels (Spearman rho(18 = -0.541; P = 0.014 at the end of the study. In conclusion, the results of this study suggest that an exercise intervention administered to breast cancer patients undergoing medical treatment may assist in the mitigation of some treatment side effects, including decreased TCI, increased fatigue, and negative changes in body composition.

  3. Habitual sleep variability, not sleep duration, is associated with caloric intake in adolescents.

    Science.gov (United States)

    He, Fan; Bixler, Edward O; Berg, Arthur; Imamura Kawasawa, Yuka; Vgontzas, Alexandros N; Fernandez-Mendoza, Julio; Yanosky, Jeff; Liao, Duanping

    2015-07-01

    The objective of this study was to investigate the associations between objectively measured habitual sleep duration (HSD), habitual sleep variability (HSV), and energy and snack intake in adolescents. We used data from 324 adolescents who participated in the Penn State Child Cohort follow-up examination. Actigraphy was used over seven consecutive nights to estimate nightly sleep duration. The seven-night mean and standard deviation of sleep duration were used to represent HSD and HSV, respectively. The Youth/Adolescent Food Frequency Questionnaire was used to obtain the daily average total energy, protein, fat, and carbohydrate intake, and number of snacks consumed. Linear regression models were used to investigate the associations between habitual sleep patterns and caloric, protein, fat, and carbohydrate intake. Proportional odds models were used to associate habitual sleep patterns with snack consumption. After adjusting for age, sex, race, body mass index (BMI) percentile, and smoking status, an increased HSV was associated with a higher energy intake, particularly from fat and carbohydrate. For example, with a 1-h increase in HSV, there was a 170 (66)-kcal increase in the daily total energy intake. An increased HSV was also related to increased snack consumption, especially snacks consumed after dinner. For instance, a 1-h increase in HSV was associated with 65% and 94% higher odds of consuming more snacks after dinner during school/workdays and weekends/vacation days, respectively. Neither energy intake nor snack consumption was significantly related to HSD. High habitual sleep variability, not habitual sleep duration, is related to increased energy and food consumption in adolescents. Maintaining a regular sleep pattern may decrease the risk of obesity in adolescents. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Science.gov (United States)

    Song, Guangyan; Hou, Jihua; Li, Ying; Zhang, Jiahui; He, Nianpeng

    2016-01-01

    Leaf caloric value (LCV) reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP). Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1), defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation) may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  5. Leaf Caloric Value from Tropical to Cold-Temperate Forests: Latitudinal Patterns and Linkage to Productivity.

    Directory of Open Access Journals (Sweden)

    Guangyan Song

    Full Text Available Leaf caloric value (LCV reflects the capacity of a leaf to fix and accumulate solar energy through photosynthesis. We systematically investigated the LCV of 745 plant species in 9 forests, representing a range of tropical to cold-temperate forests along the 4700-km North-South Transect of Eastern China. The goals were to explore the latitudinal patterns of LCV at the levels of species, plant functional group, and community and to establish the relationship between LCV and gross primary productivity (GPP. Our results showed that LCV for all species ranged from 12.85 to 22.15 KJ g-1 with an average of 18.46 KJ g-1. Plant functional groups had a significant influence on LCV, with trees > shrubs > herbs, conifers > broadleaved trees, and evergreens > deciduous trees. The different values of LCV represented the long-term evolution and adaptation of plant species to different environments. Unexpectedly, no apparent latitudinal trends of LCV at community level were observed, although LCV at the species level clearly decreased with increasing latitude. Use efficiency of LCV (CUE, gC KJ-1, defined as the ratio of GPP to total LCV at the community level, varied quadratic with latitude and was lower in the middle latitudes. Climate (temperature and precipitation may explain 52.9% of the variation in spatial patterns of CUE, which was positively correlated with aridity. Our findings are the first large-scale report of the latitudinal patterns of LCV in forests at the species, plant functional group, and community levels and provide new insights into the relationship between LCV and ecosystem functions in forest communities.

  6. Influence of parenteral feeding on spontaneous caloric intake and food selection in rats.

    Science.gov (United States)

    Giner, M; Kawashima, Y; Campos, A C; Meguid, M M

    1992-04-01

    We compared spontaneous caloric intake (SCI) of rats exclusively receiving chow to SCI of rats given the choice of chow or Parmesan cheese, and then examined the influence of parenteral feeding on SCI and food selection. Six rats in a Chow Diet Group were offered Purina chow for 21 days, while five rats in a Choice Diet Group were offered Parmesan cheese or the same chow. Daily SCI (kcal/day) and body weight gain (BWG; g/day) were determined. Rats in the Choice Diet Group ate twice as much cheese as chow for the first 3 days of the experiment. Thereafter, SCI and BWG became comparable in both groups, with no significant differences for the rest of the study. In another group of nine rats, a central venous catheter was inserted. After 7 days, rats were offered chow and water ad libitum during the infusion of normal saline at 3 ml/hour for 3 days (Saline). Then, normal saline was replaced by a total parenteral nutrition (TPN) mixture of glucose, fat, and amino acid providing 85 kcal/day, and rats were randomized to eat either Chow Diet or Choice Diet. In both groups, SCI during TPN was significantly reduced as compared to the SCI on Saline. However, rats in the Choice Diet Group ate three times more chow than cheese during TPN. We conclude that a) food preference can increase SCI for short periods of time; b) TPN reduces SCI; c) TPN modifies food preference; and d) food preference does not increase SCI during TPN.

  7. Magneto-caloric effect in the pseudo-binary intermetallic YPrFe{sub 17} compound

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Pablo [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Gorria, Pedro, E-mail: pgorria@uniovi.es [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Sanchez Llamazares, Jose L. [Division de Materiales Avanzados, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Perez, Maria J. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Franco, Victorino [Departamento de Fisica de la Materia Condensada, ICMSE-CSIC, Universidad de Sevilla, P.O. Box 1065, 41080 Sevilla (Spain); Reiffers, Marian; Kovac, Jozef [Institute of Experimental Physics, Watsonova 47, SK-04001 Kosice (Slovakia); Puente-Orench, Ines [Institute Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble (France); Blanco, Jesus A. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer YPrFe{sub 17} exhibits a broad {Delta}S{sub M}(T) associated with the ferro-to-paramagnetic phase transition (T{sub C} Almost-Equal-To 290 K). Black-Right-Pointing-Pointer We obtain |{Delta}S{sub M}| Almost-Equal-To 2.3 J kg{sup -1} K{sup -1} and RCP Almost-Equal-To 100 J kg{sup -1}for a magnetic field change of 1.5 T. Black-Right-Pointing-Pointer A single master curve for {Delta}S{sub M} is found when compared with other isostructural R{sub 2}Fe{sub 17} binary alloys. - Abstract: We have synthesized the intermetallic YPrFe{sub 17} compound by arc-melting. X-ray and neutron powder diffraction show that the crystal structure is rhombohedral with R3{sup Macron }m space group (Th{sub 2}Zn{sub 17}-type). The investigated compound exhibits a broad isothermal magnetic entropy change {Delta}S{sub M}(T) associated with the ferro-to-paramagnetic phase transition (T{sub C} Almost-Equal-To 290 K). The |{Delta}S{sub M}| ( Almost-Equal-To 2.3 J kg{sup -1} K{sup -1}) and the relative cooling power ( Almost-Equal-To 100 J kg{sup -1}) have been calculated for applied magnetic field changes up to 1.5 T. A single master curve for {Delta}S{sub M} under different values of the magnetic field change can be obtained by a rescaling of the temperature axis. The results are compared and discussed in terms of the magneto-caloric effect in the isostructural R{sub 2}Fe{sub 17} (R = Y, Pr and Nd) binary intermetallic alloys.

  8. Tecnologías emergentes para la conservación de alimentos sin calor

    Directory of Open Access Journals (Sweden)

    Fernández Molina, Juan José

    2001-01-01

    Full Text Available Not available

    Se han investigado los principios básicos de tres tecnologías emergentes para pasteurizar y esterilizar alimentos sin empleo del calor Mediante numerosos estudios se ha comprobado la efectividad de los campos eléctricos pulsantes de alta intensidad (CEPAI, los pulsos de luz (PL y los campos magnéticos oscilantes (CMO en la destrucción de microorganismos y enzimas de sistemas alimentarios. En la inactivación microbiana por CEPA!, el blanco principal es la membrana celular que, al ser sometida a campos eléctricos de alta intensidad, se hace permeable formando huecos o poros cuyo tamaño se incrementa a medida que aumenta la intensidad del campo eléctrico o el tiempo de tratamiento o se reduce la resistencia iónica del medio de pulsación. Por otra parte, los PL inducen reacciones fotoquímicas y fototérmicas en los alimentos, causando la muerte de gran cantidad de microorganismos, especialmente en productos alimenticios envasados. Los CMO producen simulación o inhibición en el crecimiento y reproducción de los microorganismos, un simple pulso de intensidad de 5-10 teslas y frecuencias de 5-500 kHz es suficiente para reducir el número de microorganismos en un mínimo de 2 ciclos logarítmicos. Se ha comprobado que estas tecnologías alargan la vida de anaquel de diversos productos alimenticios y pueden ser consideradas como sustitutos parciales de los procesos convencionales de pasteurización y esterilización de alimentos por tratamientos térmicos.

  9. The ketogenic diet: initiation at goal calories versus gradual caloric advancement.

    Science.gov (United States)

    Bansal, Seema; Cramp, Laura; Blalock, Dan; Zelleke, Tesfaye; Carpenter, Jessica; Kao, Amy

    2014-01-01

    Inpatient initiation of the ketogenic diet has historically involved fasting followed by gradual advancement of calories and/or diet ratio. Complications during this initiation period are common. We sought to determine if the initiation of the diet at goal calories would reduce these complications while maintaining efficacy. Sixty patients were admitted to a tertiary care hospital for elective initiation of the ketogenic diet between October 2007 and January 2013. All patients were placed on a ketogenic diet initiation pathway. In 2010, the pathway was modified from gradual caloric advancement to initiation at goal calories. We selected 30 consecutive patients before and after the change for comparison. Each child's record was reviewed for the occurrence of hypoglycemia, number of days to reach full ketosis (defined as 4 + urine ketones), acidosis requiring commencement of sodium citrate, length of admission, and long-term efficacy. Both methods of initiation had similar rates of dehydration, vomiting, lethargy, and irritability. More patients initiated at goal received sodium citrate (P = 0.005); however, mean daily values of carbon dioxide were not significantly different. Onset of ketosis was slightly delayed (P = 0.009) in patients initiated at goal, but length of stay was not affected (P > 0.1). Hypoglycemia was uncommon and rates were similar between the groups. Efficacy at 3 months was better in patients initiated at full calories (P ketogenic diet full calories is a reasonable alternative to the current standard practice of gradual advancement of calories and/or diet ratio. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Mild caloric restriction up-regulates the expression of prohibitin: A proteome study

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Shoko; Masuda, Junko; Shimagami, Hiroshi [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Ohta, Yutaka; Kanda, Tomomasa [Research Laboratories for Health and Gustatory Science, Asahi Breweries Limited, Ibaraki (Japan); Saito, Kenji [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Corporate Sponsored Research Program ' Food for Life' , The University of Tokyo, Tokyo (Japan); Kato, Hisanori, E-mail: akatoq@mail.ecc.u-tokyo.ac.jp [Department of Applied Biological Chemistry, The University of Tokyo, Tokyo (Japan); Corporate Sponsored Research Program ' Food for Life' , The University of Tokyo, Tokyo (Japan)

    2011-02-18

    Research highlights: {yields} Proteomic analysis was performed to elucidate physiological alterations induced by mild CR. {yields} The results suggest good reproducibility and possibility to grasp the important response of CR. {yields} The increase in prohibitin abundance was observed in CR groups by proteomic analysis. {yields} We hypothesize that prohibitin might be involved in the longevity induced by CR. -- Abstract: Caloric restriction (CR) is well known to expand lifespan in a variety of species and to retard many age-related diseases. The effects of relatively mild CR on the proteome profile in relation to lifespan have not yet been reported, despite the more extensive studies of the stricter CR conditions. Thus, the present study was conducted to elucidate the protein profiles in rat livers after mild CR for a relatively short time. Young growing rats were fed CR diets (10% and 30% CR) for 1 month. We performed the differential proteomic analysis of the rat livers using two-dimensional electrophoresis combined with MALDI-TOF mass spectrometry. The most remarkable protein among the differentially expressed proteins was found to be prohibitin, the abundance of which was increased by 30% CR. Prohibitin is a ubiquitously expressed protein shown to suppress cell proliferation and to be related to longevity. The increase in prohibitin was observed both in 10% and 30% CR by Western blot analysis. Furthermore, induction of AMP-activated kinase (AMPK) protein, related to the actions of prohibitin in promoting longevity, was observed. The increased prohibitin level in response to subtle CR suggests that this increase may be one of the early events leading to the expansion of lifespan in response to CR.

  11. Shifts in the distribution of mass densities is a signature of caloric restriction in Caenorhabditis elegans.

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    Alfonso Reina

    Full Text Available Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The density of worms in synchronized populations of wildtype N2 C. elegans grown under standard solid-phase culture conditions was normally distributed, with distributions peaked sharply at a mean of 1.091 g/cm(3 for L1, L2 and L3 larvae, 1.087 g/cm(3 for L4 larvae, 1.081 g/cm(3 for newly molted adults, and 1.074 g/cm(3 at 24 hours of adulthood. The density of adult worms under starvation stress fell well outside this range, falling to a mean value of 1.054 g/cm(3 after eight hours of starvation. This decrease in density correlated with the consumption of stored glycogen in the food-deprived worms. The density of the worms increased when deprived of food for longer durations, corresponding to a shift in the response of the worms: worms sacrifice their bodies by retaining larvae, which consume the adults from within. Density-based screens with the drug Ivermectin on worms cultured on single plates resulted in a clear bimodal (double-peaked distribution of densities corresponding to drug exposed and non-exposed worms. Thus, measurements of changes in density could be used to conduct screens on the effects of drugs on several populations of worms cultured on single plates.

  12. Shifts in the Distribution of Mass Densities Is a Signature of Caloric Restriction in Caenorhabditis elegans

    Science.gov (United States)

    Laromaine, Anna; Samuel, Aravinthan D. T.; Whitesides, George M.

    2013-01-01

    Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C. elegans. The density of worms in synchronized populations of wildtype N2 C. elegans grown under standard solid-phase culture conditions was normally distributed, with distributions peaked sharply at a mean of 1.091 g/cm3 for L1, L2 and L3 larvae, 1.087 g/cm3 for L4 larvae, 1.081 g/cm3 for newly molted adults, and 1.074 g/cm3 at 24 hours of adulthood. The density of adult worms under starvation stress fell well outside this range, falling to a mean value of 1.054 g/cm3 after eight hours of starvation. This decrease in density correlated with the consumption of stored glycogen in the food-deprived worms. The density of the worms increased when deprived of food for longer durations, corresponding to a shift in the response of the worms: worms sacrifice their bodies by retaining larvae, which consume the adults from within. Density-based screens with the drug Ivermectin on worms cultured on single plates resulted in a clear bimodal (double-peaked) distribution of densities corresponding to drug exposed and non-exposed worms. Thus, measurements of changes in density could be used to conduct screens on the effects of drugs on several populations of worms cultured on single plates. PMID:23922767

  13. Calibration of a Fusion Experiment to Investigate the Nuclear Caloric Curve

    Science.gov (United States)

    Keeler, Ashleigh

    2017-09-01

    In order to investigate the nuclear equation of state (EoS), the relation between two thermodynamic quantities can be examined. The correlation between the temperature and excitation energy of a nucleus, also known as the caloric curve, has been previously observed in peripheral heavy-ion collisions to exhibit a dependence on the neutron-proton asymmetry. To further investigate this result, fusion reactions (78Kr + 12C and 86Kr + 12C) were measured; the beam energy was varied in the range 15-35 MeV/u in order to vary the excitation energy. The light charged particles (LCPs) evaporated from the compound nucleus were measured in the Si-CsI(TI)/PD detector array FAUST (Forward Array Using Silicon Technology). The LCPs carry information about the temperature. The calibration of FAUST will be described in this presentation. The silicon detectors have resistive surfaces in perpendicular directions to allow position measurement of the LCP's to better than 200 um. The resistive nature requires a position-dependent correction to the energy calibration to take full advantage of the energy resolution. The momentum is calculated from the energy of these particles, and their position on the detectors. A parameterized formula based on the Bethe-Bloch equation was used to straighten the particle identification (PID) lines measured with the dE-E technique. The energy calibration of the CsI detectors is based on the silicon detector energy calibration and the PID. A precision slotted mask enables the relative positions of the detectors to be determined. DOE Grant: DE-FG02-93ER40773 and REU Grant: PHY - 1659847.

  14. Balanced Caloric Restriction Minimizes Changes Caused by Aging on the Colonic Myenteric Plexus.

    Science.gov (United States)

    Mari, Renata de Britto; Stabille, Sandra Regina; de Faria, Haroldo Garcia; Pereira, Joice Naiara Bertaglia; Guimarães, Juliana Plácido; Marinsek, Gabriela Pustiglione; de Souza, Romeu Rodrigues

    2017-07-31

    Aging can promote significant morphofunctional changes in the gastrointestinal tract (GIT). Regulation of GIT motility is mainly controlled by the myenteric neurons of the enteric nervous system. Actions that aim at decreasing the aging effects in the GIT include those related to diet, with caloric restriction (CR). The CR is achieved by controlling the amount of food or by manipulating the components of the diet. Therefore, the objective of this study was to evaluate different levels of CR on the plasticity of nicotinamide adenine dinucleotide phosphate- (NADPH-) reactive myenteric neurons in the colon of Wistar rats during the aging process using ultrastructural (transmission electron microscopy) and morphoquantitative analysis. Wistar male rats (Rattus norvegicus) were distributed into 4 groups (n = 10/group): C, 6-month-old animals; SR, 18-month-old animals fed a normal diet; CRI, 18-month-old animals fed a 12% CR diet; CRII, 18-month-old animals fed a 31% CR diet. At 6 months of age, animals were transferred to the laboratory animal facility, where they remained until 18 months of age. Animals of the CRI and CRII groups were submitted to CR for 6 months. In the ultrastructural analysis, a disorganization of the periganglionar matrix with the aging was observed, and this characteristic was not observed in the animals that received hypocaloric diet. It was observed that the restriction of 12.5% and 31% of calories in the diet minimized the increase in density and cell profile of the reactive NADPH neurons, increased with age. This type of diet may be adapted against gastrointestinal disturbances that commonly affect aging individuals.

  15. COMPARAÇÃO ENTRE TÉCNICAS NUMÉRICAS PARA A RESOLUÇÃO DO PROBLEMA DE TRANSFERÊNCIA DE CALOR EM ALIMENTOS ENLATADOS

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    A.D. RODRIGUES

    1998-05-01

    Full Text Available Este trabalho apresenta a comparação das técnicas de resolução numérica de Diferenças Finitas e Runge-Kutta-Gill de 4a ordem com passo de integração variável para a simulação do modelo de transferência de calor em regime transiente bidimensional em coordenadas cilíndricas e unidimensional em coordenadas esféricas, aplicado a alimentos enlatados processados em autoclave, observando-se a rapidez e a precisão de integração comparados aos perfis reais de tempo/temperatura, incluindo desvios de processo. Além disso, uma análise de sensibilidade paramétrica na difusividade térmica foi realizada na tentativa de quantificar a influência que essa propriedade possui na resolução numérica. Para tanto, foram realizados ensaios de penetração de calor em autoclave a vapor, utilizando-se latas cilíndricas de 75x90 e 100x110 contendo simulantes de alimentos com características de aquecimento por condução e convecção.This work presents a comparison of the integration quickness and precision between the techniques of numerical resolution of Finite Differences and Runge-Kutta-Gill of fourth order with variable integration pass, to do simulation of the unsteady-state heat transfer model, two-dimensional in cylindrical coordinates and one-dimensional in spherical coordinates, applied to canned foods processed in retorts, showing advantages for the technique of Runge-Kutta-Gill. It was also accomplished a parametric sensitivity analysis in the thermal diffusivity indicating a great influence of this parameter in the numerical solution. The mathematical simulation were compared with results of real heat penetration tests done in steam retort, using cylindrical cans filled with bentonite suspensions simulating foods with heat characteristics resembling heat conduction and heat convection.

  16. The role of a pre-load beverage on gastric volume and food intake: comparison between non-caloric carbonated and non-carbonated beverage

    Directory of Open Access Journals (Sweden)

    Zito Francesco

    2011-10-01

    Full Text Available Abstract Background There is conflicting data on the effects of carbon dioxide contained in beverages on stomach functions. We aimed to verify the effect of a pre-meal administration of a 300 ml non-caloric carbonated beverage (B+CO2 compared to water or a beverage without CO2 (B-CO2, during a solid (SM and a liquid meal (LM on: a gastric volume, b caloric intake, c ghrelin and cholecystokinin (CCK release in healthy subjects. Methods After drinking the beverages (Water, B-CO2, B+CO2, ten healthy subjects (4 women, aged 22-30 years; BMI 23 ± 1 were asked to consume either an SM or an LM, at a constant rate (110 kcal/5 min. Total gastric volumes (TGV were evaluated by Magnetic Resonance Imaging after drinking the beverage and at maximum satiety (MS. Total kcal intake at MS was evaluated. Ghrelin and CCK were measured by enzyme immunoassay until 120 min after the meal. Statistical calculations were carried out by paired T-test and analysis of variance (ANOVA. The data is expressed as mean ± SEM. Results TGV after B+CO2 consumption was significantly higher than after B-CO2 or water (p 2: 837 ± 66; B+CO2: 774 ± 66 or the LM (630 ± 111; 585 ± 88; 588 ± 95. Area under curve of ghrelin was significantly (p 2 compared to B+CO2 and water (26.2 ± 4.5; 27.1 ± 5.1. No significant differences were found for ghrelin during LM, and for CCK during both SM and LM after all beverages. Conclusions The increase in gastric volume following a 300 ml pre-meal carbonated beverage did not affect food intake whether a solid or liquid meal was given. The consistency of the meal and the carbonated beverage seemed to influence ghrelin release, but were unable, under our experimental conditions, to modify food intake in terms of quantity. Further studies are needed to verify if other food and beverage combinations are able to modify satiation.

  17. Deletion of Suppressor of Cytokine Signaling 3 from Forebrain Neurons Delays Infertility and Onset of Hypothalamic Leptin Resistance in Response to a High Caloric Diet.

    Science.gov (United States)

    McEwen, Hayden J L; Inglis, Megan A; Quennell, Janette H; Grattan, David R; Anderson, Greg M

    2016-07-06

    The cellular processes that cause high caloric diet (HCD)-induced infertility are poorly understood but may involve upregulation of suppressor of cytokine signaling (SOCS-3) proteins that are associated with hypothalamic leptin resistance. Deletion of SOCS-3 from brain cells is known to protect mice from diet-induced obesity, but the effects on HCD-induced infertility are unknown. We used neuron-specific SOCS3 knock-out mice to elucidate this and the effects on regional hypothalamic leptin resistance. As expected, male and female neuron-specific SOCS3 knock-out mice were protected from HCD-induced obesity. While female wild-type mice became infertile after 4 months of HCD feeding, infertility onset in knock-out females was delayed by 4 weeks. Similarly, knock-out mice had delayed leptin resistance development in the medial preoptic area and anteroventral periventricular nucleus, regions important for generation of the surge of GnRH and LH that induces ovulation. We therefore tested whether the suppressive effects of HCD on the estradiol-induced GnRH/LH surge were overcome by neuron-specific SOCS3 knock-out. Although only 20% of control HCD-mice experienced a preovulatory-like LH surge, LH surges could be induced in almost all neuron-specific SOCS3 knock-out mice on this diet. In contrast to females, HCD-fed male mice did not exhibit any fertility decline compared with low caloric diet-fed males despite their resistance to the satiety effects of leptin. These data show that deletion of SOCS3 delays the onset of leptin resistance and infertility in HCD-fed female mice, but given continued HCD feeding this state does eventually occur, presumably in response to other mechanisms inhibiting leptin signal transduction. Obesity is commonly associated with infertility in humans and other animals. Treatments for human infertility show a decreased success rate with increasing body mass index. A hallmark of obesity is an increase in circulating leptin levels; despite this, the

  18. Effect of feeding a weight loss food beyond a caloric restriction period on body composition and resistance to weight gain in dogs.

    Science.gov (United States)

    Floerchinger, Amanda M; Jackson, Matthew I; Jewell, Dennis E; MacLeay, Jennifer M; Paetau-Robinson, Inke; Hahn, Kevin A

    2015-08-15

    To determine the effect of feeding a food with coconut oil and supplemental L-carnitine, lipoic acid, lysine, leucine, and fiber on weight loss and maintenance in dogs. Prospective clinical study. 50 overweight dogs. The study consisted of 2 trials. During trial 1, 30 dogs were allocated to 3 groups (10 dogs/group) to be fed a dry maintenance dog food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 dogs was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1% to 2%/wk (weight loss phase). Next, each dog was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Dogs were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase. During trial 1, dogs in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, dogs lost a significant amount of body weight and fat mass but retained lean body mass (LBM) during the weight loss phase and continued to lose body fat but gained LBM during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism and LBM retention were improved from baseline for dogs fed the test food. Results suggested that feeding overweight dogs the test food caused weight loss and improvements in body condition during the weight-maintenance phase, possibly because the food composition improved energy metabolism.

  19. Effect of feeding a weight loss food beyond a caloric restriction period on body composition and resistance to weight gain in cats.

    Science.gov (United States)

    Floerchinger, Amanda M; Jackson, Matthew I; Jewell, Dennis E; MacLeay, Jennifer M; Hahn, Kevin A; Paetau-Robinson, Inke

    2015-08-15

    To determine the effect of feeding a food with coconut oil and supplemental L-carnitine, lysine, leucine, and fiber on weight loss and maintenance in cats. Prospective clinical study. 50 overweight cats. The study consisted of 2 trials. During trial 1, 30 cats were allocated to 3 groups (10 cats/group) to be fed a dry maintenance cat food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 cats was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1%/wk (weight loss phase). Next, each cat was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Cats were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase. During trial 1, cats in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, cats lost a significant amount of body weight and fat mass but retained lean body mass during the weight loss phase and continued to lose body weight and fat mass but gained lean body mass during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism was improved from baseline for cats fed the test food. Results suggested that feeding overweight cats the test food caused weight loss and improvements in body condition during the weight maintenance phase, possibly because the food composition improved energy metabolism.

  20. Padrão eletroforético de proteínas resistentes ao calor em sementes de milho Electrophorectic pattern of the heat resistant proteins of corn seeds

    Directory of Open Access Journals (Sweden)

    Solange Carvalho Barrios Roveri José

    2005-02-01

    Full Text Available Na aquisição e manutenção da tolerância à dessecação de sementes, há vários mecanismos envolvidos, entre eles a indução das proteínas resistentes ao calor. O objetivo deste trabalho foi avaliar mudanças no padrão eletroforético das proteínas resistentes ao calor de sementes de milho submetidas a alta temperatura de secagem, associando-as à sua tolerância. Foram utilizadas sementes de linhagens, híbridos simples e híbridos recíprocos colhidas com teor de água de aproximadamente 35% e secadas a 45°C. Sementes das linhagens secadas à sombra foram utilizadas como controle e sua qualidade fisiológica foi avaliada por meio do teste de germinação. As proteínas resistentes ao calor foram extraídas de eixos embrionários das sementes em tampão Tris HCl 0,05 M. Não foi possível determinar uma banda específica da fração das proteínas resistentes ao calor que possa servir como marcador da tolerância à alta temperatura de secagem. Houve estabilidade nos padrões de bandas das proteínas provenientes de sementes submetidas à secagem artificial e natural, mesmo quando foram observadas variações nos valores de germinação. Os padrões eletroforéticos das proteínas resistentes ao calor foram semelhantes entre as sementes híbridas e os respectivos recíprocos.Several mechanisms are involved in the acquisition and maintenance of desiccation tolerance by the seeds. One of these mechanisms is related to the induction of heat resitant proteins. The objective of this work was to evaluate changes in the electophorectic patterns of the heat resistant proteins of corn seeds submitted to high drying temperature associating their expression with drying tolerance. Seeds of breeding lines, simple hybrids and respective reciprocals hybrids were utilized. The seeds were harvested with approximately 35% of water content and dried at 45°C. Seeds of lines dried under shadow were used as control and the physiological quality was

  1. The urban climate: urban heat island of Salamanca El clima de las ciudades: isla de calor de Salamanca

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    Mª Salud Alonso García

    2004-12-01

    Full Text Available We have determined the existence of the urban heat island (UHI in a medium-sized city, with an extreme climate and few important foci of industrial pollution. It was seen that urban warming can arise in cities of these characteristics, being able to influence in the alive beings of the zone. By comparing the temperature series in an urban area and those from a nearby rural area, we studied the temporal evolution of the intensity of the UHI for the three-year period between 1996 and 1998. We detected two phenomenons: nocturnal heat island, when the difference of temperature between city and rural zone is positive, and diurnal heat island, when is negative. The most intense nocturnal heat island was seen in autumn, and the most intense diurnal heat island was seen in spring. Statistical study of the annual series corresponding to the night-time heat island permits a definition for Salamanca: a weak island, such as the one showing an intensity lower than 2.0 oC, a moderate island, if the intensity lies between 2.0 oC and 4.0 oC, and an intense island when a values greater than 4.0 oC is passed.En este trabajo se ha determinado la existencia de la isla de calor urbana (ICU, en una ciudad de tamaño medio, con un clima extremado y focos industriales de poca actividad. Con lo que se puede comprobar cómo afecta el calentamiento urbano a ciudades de estas características, pudiendo influir en los seres vivos de la zona. La existencia del fenómeno isla de calor, y su evolución en el tiempo, se han observado comparando los datos de temperatura registrados en una estación meteorológica situada en la ciudad, con los de otra estación fuera del radio de acción de la urbe, durante el período 1996-1998. Se han detectado dos fenómenos: la isla de calor nocturna, cuando la diferencia térmica entre la ciudad y la zona rural es positiva, que presenta sus valores más altos en otoño, y la isla de calor diurna, cuando la diferencia es negativa, que

  2. Soluble Fermentable Dietary Fibre (Pectin) Decreases Caloric Intake, Adiposity and Lipidaemia in High-Fat Diet-Induced Obese Rats

    Science.gov (United States)

    Adam, Clare L.; Thomson, Lynn M.; Williams, Patricia A.; Ross, Alexander W.

    2015-01-01

    Consumption of a high fat diet promotes obesity and poor metabolic health, both of which may be improved by decreasing caloric intake. Satiety-inducing ingredients such as dietary fibre may be beneficial and this study investigates in diet-induced obese (DIO) rats the effects of high or low fat diet with or without soluble fermentable fibre (pectin). In two independently replicated experiments, young adult male DIO rats that had been reared on high fat diet (HF; 45% energy from fat) were given HF, low fat diet (LF; 10% energy from fat), HF with 10% w/w pectin (HF+P), or LF with 10% w/w pectin (LF+P) ad libitum for 4 weeks (n = 8/group/experiment). Food intake, body weight, body composition (by magnetic resonance imaging), plasma hormones, and plasma and liver lipid concentrations were measured. Caloric intake and body weight gain were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Body fat mass increased in HF, was maintained in LF, but decreased significantly in LF+P and HF+P groups. Final plasma leptin, insulin, total cholesterol and triglycerides were lower, and plasma satiety hormone PYY concentrations were higher, in LF+P and HF+P than in LF and HF groups, respectively. Total fat and triglyceride concentrations in liver were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Therefore, the inclusion of soluble fibre in a high fat (or low fat) diet promoted increased satiety and decreased caloric intake, weight gain, adiposity, lipidaemia, leptinaemia and insulinaemia. These data support the potential of fermentable dietary fibre for weight loss and improving metabolic health in obesity. PMID:26447990

  3. ISOTERMAS E CALOR ISOSTÉRICO DE ADSORÇÃO DA ÁGUA DO AMIDO DE QUINOA

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    AUGUSTO PUMACAHUA RAMOS

    2017-07-01

    Full Text Available A quinoa possui mais de 60% de amido, sendo uma alternativa de extração e comercialização. Para isto é necessário conhecer o comportamento do amido frente à temperatura e umidade relativa do ar. O objetivo desta pesquisa foi avaliar as isotermas de adsorção do amido de quinoa em cinco temperaturas (20, 30, 40, 50 e 60ºC e dez atividades de água (0,036 a 0,907. Os pontos experimentais foram ajustados aos modelos matemáticos GAB, Oswin, Henderson, Peleg e Ferro-Foltan. Foram determinadas as energias de ativação da adsorção da água pelas constantes do modelo GAB e o calor isostérico pelo modelo de Peleg. As isotermas mostraram ser do tipo II na classificação de Brunauer. Os teores de água da monocamada (Xm determinados pelo modelo de GAB variaram de 7,90% a 10,38% base seca (b.s. para temperaturas de 60 e 20°C e as energias de ativação obtidas pelas constantes Xm, C e K do modelo de GAB foram de 300; 160 e 6 kJ/kg, respectivamente. O calor isostérico de adsorção foi de 3732 kJ/kg para umidade de equilíbrio de 0,5% b.s. e diminuiu com o aumento da umidade até valor próximo ao calor latente de vaporização da água pura a 36% b.s. As propriedades determinadas são características de amidos com elevado teor de amilopectina.

  4. Soluble Fermentable Dietary Fibre (Pectin Decreases Caloric Intake, Adiposity and Lipidaemia in High-Fat Diet-Induced Obese Rats.

    Directory of Open Access Journals (Sweden)

    Clare L Adam

    Full Text Available Consumption of a high fat diet promotes obesity and poor metabolic health, both of which may be improved by decreasing caloric intake. Satiety-inducing ingredients such as dietary fibre may be beneficial and this study investigates in diet-induced obese (DIO rats the effects of high or low fat diet with or without soluble fermentable fibre (pectin. In two independently replicated experiments, young adult male DIO rats that had been reared on high fat diet (HF; 45% energy from fat were given HF, low fat diet (LF; 10% energy from fat, HF with 10% w/w pectin (HF+P, or LF with 10% w/w pectin (LF+P ad libitum for 4 weeks (n = 8/group/experiment. Food intake, body weight, body composition (by magnetic resonance imaging, plasma hormones, and plasma and liver lipid concentrations were measured. Caloric intake and body weight gain were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Body fat mass increased in HF, was maintained in LF, but decreased significantly in LF+P and HF+P groups. Final plasma leptin, insulin, total cholesterol and triglycerides were lower, and plasma satiety hormone PYY concentrations were higher, in LF+P and HF+P than in LF and HF groups, respectively. Total fat and triglyceride concentrations in liver were greatest in HF, lower in LF and HF+P, and lowest in the LF+P group. Therefore, the inclusion of soluble fibre in a high fat (or low fat diet promoted increased satiety and decreased caloric intake, weight gain, adiposity, lipidaemia, leptinaemia and insulinaemia. These data support the potential of fermentable dietary fibre for weight loss and improving metabolic health in obesity.

  5. Distúrbios causados pelo frio e pelo calor durante corridas de longa distância

    Directory of Open Access Journals (Sweden)

    1999-06-01

    Full Text Available Muitos corredores amadores e de elite participam todos os anos de corridas de longa distância. Quando estes eventos ocorrem em temperaturas altas ou baixas, aumenta o risco de distúrbios térmicos. Contudo, a hipertermia induzida pelo exercício, a hipotermia, a desidratação e outros problemas relacionados podem ser minimizados através de esclarecimentos e um preparo antes do evento. Este documento fornece recomendações para o diretor médico e outras autoridades da organização das corridas nas seguintes áreas: planejamento, profissionais envolvidos na organização, instalações, suprimentos, equipamento e comunicação; fornecimento de esclarecimentos aos participantes; avaliação do estresse térmico; fornecimento de líquidos; e prevenção de questões legais em potencial. Este posicionamento oficial também descreve as condições predisponentes, as formas de diagnóstico e o tratamento dos quatro distúrbios ambientais mais comuns: exaustão pelo calor, colapso pelo calor, hipotermia e congelamento de extremidades. Os objetivos deste documento são: 1 Educar os organizadores e os participantes de corridas de longa distância a respeito das formas mais comuns de distúrbios térmicos incluindo as condições predisponentes, sinais de alerta, suscetibilidade e a redução de sua incidência; 2 Alertar os organizadores sobre as suas responsabilidades civis em potencial no que concerne à segurança do evento e à prevenção de lesões; 3 Recomendar que os organizadores consultem arquivos locais de meteorologia e planejem eventos em horas que provavelmente causem menos estresse térmico de modo a minimizar os efeitos deletérios sobre os participantes; 4 Estimular os organizadores a alertar os participantes sobre o estresse térmico no dia da corrida e as suas implicações no que tange aos distúrbios causados pelo frio e pelo calor; 5 Informar os organizadores sobre as ações preventivas que podem reduzir a incidência dos

  6. Transferencia de calor durante la congelación, el almacenamiento y la descongelación de alimentos

    OpenAIRE

    Salvadori, Viviana Olga

    1994-01-01

    En el presente trabajo se estudian distintos aspectos relacionados con la congelación y el almacenamiento de productos congelados, con los siguientes objetivos: - Optimizar el diseño de sistemas para la congelación o almacenamiento de alimentos a través de un mejor conocimiento de los fenómenos de transferencia de calor que tienen lugar en los mismos. Esto involucra un adecuado dimensionamiento de los equipos con el consiguiente ahorro en los costos de inversión. - Desar...

  7. Adaptación de las TIC al Laboratorio de Transferencia de Calor en el Instituto Minas Fredonia

    OpenAIRE

    Pérez Montes, Ricardo Adolfo

    2014-01-01

    Resumen: Se implementó el laboratorio de Transferencia de Calor con cinco puestos de trabajo computarizado. Cada uno está constituido por un sistema de adquisición utilizando la tarjeta Arduino y sensores de temperatura, sobre el sistema operativo Windows 8. Se probó con una Unidad de Enseñanza Potencialmente Significativa-UEPS para los grados Noveno, décimo y once en la Institución Educativa de Minas Fredonia, institución de media técnica agropecuaria. Para comparar las bondades en la enseña...

  8. Chemotherapy for Isolated Locoregional Recurrence of Breast Cancer: The CALOR Randomised Trial

    Science.gov (United States)

    Aebi, Stefan; Gelber, Shari; Anderson, Stewart J.; Láng, István; Robidoux, André; Martín, Miguel; Nortier, Johan W.R.; Paterson, Alexander H.G.; Rimawi, Mothaffar F.; Cañada, José Manuel Baena; Thürlimann, Beat; Murray, Elizabeth; Mamounas, Eleftherios P.; Geyer, Charles E.; Price, Karen N.; Coates, Alan S.; Gelber, Richard D.; Rastogi, Priya; Wolmark, Norman; Wapnir, Irene L.

    2014-01-01

    BACKGROUND Patients with isolated locoregional recurrences (ILRR) of breast cancer have a high risk of distant metastasis and death from breast cancer. We investigated adjuvant chemotherapy for such patients in a randomised clinical trial. METHODS The CALOR trial (clinicaltrials.gov NCT00074152) accrued patients 2003-2010. The 162 patients with resected ILRR were centrally randomised using permuted blocks and stratified by prior chemotherapy, ER/PgR status, and location of ILRR. Eighty-five were allocated to chemotherapy (type selected by the investigator; multidrug for at least four courses recommended) and 77 to no chemotherapy. Patients with oestrogen receptor-positive ILRR received adjuvant endocrine therapy; radiation therapy was mandated for patients with microscopically involved surgical margins, and anti-HER2 therapy was optional. The primary endpoint was disease-free survival (DFS). All analyses were by intention to treat. FINDINGS At a median follow up of 4·9 (IQR 3.6,6.0) years we observed 24 DFS events and nine deaths in the chemotherapy group compared with 34 DFS events and 21 deaths in the no chemotherapy group. Five-year DFS was 69% vs. 57%, (hazard ratio for chemotherapy versus no chemotherapy, 0·59; 95% confidence interval 0·35 to 0·99; P=0·046) and five-year overall survival was 88% vs. 76%, (hazard ratio, 0·41; 95% CI, 0·19 to 0·89; P=0·02). Adjuvant chemotherapy was significantly more effective for women with oestrogen receptor-negative disease measured in the recurrence (interaction P=0·04), but analyses of DFS based on the oestrogen receptor status of the primary tumour were not statistically significant (interaction P=0·43). Among the 85 patients who received standard chemotherapy, 12 reported SAEs. INTERPRETATION Adjuvant chemotherapy should be recommended for patients with completely resected isolated locoregional recurrences of breast cancer, especially if the recurrence is oestrogen receptor negative. FUNDING Public Service

  9. Chemotherapy for isolated locoregional recurrence of breast cancer (CALOR): a randomised trial.

    Science.gov (United States)

    Aebi, Stefan; Gelber, Shari; Anderson, Stewart J; Láng, István; Robidoux, André; Martín, Miguel; Nortier, Johan W R; Paterson, Alexander H G; Rimawi, Mothaffar F; Cañada, José Manuel Baena; Thürlimann, Beat; Murray, Elizabeth; Mamounas, Eleftherios P; Geyer, Charles E; Price, Karen N; Coates, Alan S; Gelber, Richard D; Rastogi, Priya; Wolmark, Norman; Wapnir, Irene L

    2014-02-01

    Patients with isolated locoregional recurrences (ILRR) of breast cancer have a high risk of distant metastasis and death from breast cancer. We aimed to establish whether adjuvant chemotherapy improves the outcome of such patients. The CALOR trial was a pragmatic, open-label, randomised trial that accrued patients with histologically proven and completely excised ILRR after unilateral breast cancer who had undergone a mastectomy or lumpectomy with clear surgical margins. Eligible patients were enrolled from hospitals worldwide and were centrally randomised (1:1) to chemotherapy (type selected by the investigator; multidrug for at least four courses recommended) or no chemotherapy, using permuted blocks, and stratified by previous chemotherapy, oestrogen-receptor and progesterone-receptor status, and location of ILRR. Patients with oestrogen-receptor-positive ILRR received adjuvant endocrine therapy, radiation therapy was mandated for patients with microscopically involved surgical margins, and anti-HER2 therapy was optional. The primary endpoint was disease-free survival. All analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00074152. From Aug 22, 2003, to Jan 31, 2010, 85 patients were randomly assigned to receive chemotherapy and 77 were assigned to no chemotherapy. At a median follow-up of 4·9 years (IQR 3·6-6 ·0), 24 (28%) patients had disease-free survival events in the chemotherapy group compared with 34 (44%) in the no chemotherapy group. 5-year disease-free survival was 69% (95% CI 56-79) with chemotherapy versus 57% (44-67) without chemotherapy (hazard ratio 0·59 [95% CI 0·35-0·99]; p=0·046). Adjuvant chemotherapy was significantly more effective for women with oestrogen-receptor-negative ILRR (pinteraction=0·046), but analyses of disease-free survival according to the oestrogen-receptor status of the primary tumour were not statistically significant (pinteraction=0·43). Of the 81 patients who

  10. Insights Into The Beneficial Effect Of Caloric/ Dietary Restriction For A Healthy And Prolonged Life

    Directory of Open Access Journals (Sweden)

    Rani ePallavi

    2012-08-01

    Full Text Available Over the last several years, new evidence has kept pouring in about the remarkable effect of caloric restriction (CR on the conspicuous bedfellows- aging and cancer. Through the use of various animal models, it is now well established that by reducing calorie intake one can not only increase life span but, also, lower the risk of various age related diseases such as cancer. Cancer cells are believed to be more dependent on glycolysis for their energy requirements than normal cells and, therefore, can be easily targeted by alteration in the energy-metabolic pathways, a hallmark of CR. Apart from inhibiting the growth of transplantable tumors, CR has been also shown to inhibit the development of spontaneous, radiation and chemically induced tumors. The question regarding the potentiality of the anti-tumor effect of CR in humans has been in part answered by the resistance of a cohort of women, who had suffered from anorexia in their early life, to breast cancer. However, human research on the beneficial effect of CR is still at an early stage and needs further validation. Though the complete mechanism of the anti-tumor effect of CR is far from clear, the plausible involvement of nutrient sensing pathways or IGF-1 pathways proposed for its anti-aging action cannot be overruled. In fact, cancer cell lines, mutant for proteins involved in IGF-1 pathways, failed to respond to CR. In addition, CR decreases the levels of many growth factors, anabolic hormones, inflammatory cytokines and oxidative markers that are deregulated in several cancers.In this review, we discuss the anti-tumor effect of CR, describing experiments done in vitro in tumor models and in vivo in mouse models in which the tumor was induced by means of radiation or chemical exposure, expressing oncogenes or deleting tumor suppression genes. We also discuss the proposed mechanisms of CR anti-tumor action. Lastly, we argue the necessity of gene expression studies in cancerous versus

  11. INDEPENDENCIA DE MALLA EN TUBOS TORSIONADOS PARA INTERCAMBIO DE CALOR: CASO DE ESTUDIO

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    Juan Gonzalo Ardila-Marín

    2016-01-01

    Full Text Available La dinámica de fluidos computacional (Computational Fluids Dynamics – CFD ha sido útil para la predicción del desarrollo dinámico y térmico en intercambiadores de calor de tubos curvados y torsionados, tal como lo hizo Záchar en 2010 cuando investigó la doble mejora del curvado y una vena corrugada helicoidal que simulaba la inserción de un resorte al interior del tubo, pero geometrías comerciales como Turbotec® no han sido investigadas. Además, varias herramientas comerciales para la generación de malla están disponibles, sin embargo, el efecto que la calidad y el número de elementos tienen en la solución y el aumento del costo de cómputo, obliga a equilibrar la precisión con los recursos computacionales disponibles. Esta investigación buscó la discretización del volumen de control de intercambiadores mejorados realistas, para su posterior uso en el desarrollo numérico de correlaciones para dimensionamiento y selección. Luego de una evaluación del estado del arte y del desarrollo geométrico de los volúmenes de control con las herramientas CAD SolidEdge® y DesignModeler®, se empleó la herramienta Meshing® de ANSYS Workbench® para el mallado, evaluando los métodos y las configuraciones globales y locales de malla, para su generación y la verificación de métricas; se desarrollaron estudios de independencia de malla para dos geometrías de intercambiadores, evaluando la incidencia de la calidad y el número de elementos en la convergencia del Número de Nusselt, y se validaron con resultados experimentales disponibles en la literatura. Como resultado principal se seleccionaron las mejores mallas para el estudio numérico de cada geometría y se validó la metodología propuesta. Los resultados de simulación son influenciados por la calidad del mallado, entre otros parámetros; todos deben ser evaluados antes de emplear dichos resultados en la toma de decisiones, y es necesario usar resultados experimentales para

  12. Chronic Caloric Restriction and Exercise Improve Metabolic Conditions of Dietary-Induced Obese Mice in Autophagy Correlated Manner without Involving AMPK

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    Mingxia Cui

    2013-01-01

    Full Text Available Aim. To investigate the role of AMPK activation and autophagy in mediating the beneficial effects of exercise and caloric restriction in obesity. Methods. Dietary-induced obesity mice were made and divided into 5 groups; one additional group of normal mice serves as control. Mice in each group received different combinations of interventions including low fat diet, caloric restriction, and exercise. Then their metabolic conditions were assessed by measuring serum glucose and insulin, serum lipids, and liver function. AMPK phosphorylation and autophagy activity were detected by western blotting. Results. Obese mice models were successfully induced by high fat diet. Caloric restriction consistently improved the metabolic conditions of the obese mice, and the effects are more prominent than the mice that received only exercise. Also, caloric restriction, exercise, and low fat diet showed a synergistic effect in the improvement of metabolic conditions. Western blotting results showed that this improvement was not related with the activation of AMPK in liver, skeletal muscle, or heart but correlates well with the autophagy activity. Conclusion. Caloric restriction has more prominent beneficial effects than exercise in dietary-induced obese mice. These effects are correlated with the autophagy activity and may be independent of AMPK activation.

  13. Transferência de calor transiente na agitação linear intermitente de latas Transient heat transfer by intermittent shake of cans

    Directory of Open Access Journals (Sweden)

    Homero Ferracini Gumerato

    2007-09-01

    Full Text Available Foi estudada a transferência de calor transiente na agitação linear e intermitente (ALI de embalagens metálicas contendo simulantes de alimentos, objetivando-se sua aplicação em processos de pasteurização ou esterilização e conseqüentes tratamentos térmicos mais eficientes, homogêneos e com produto de melhor qualidade. Foram utilizados quatro meios fluidos simulantes de alimentos de diferentes viscosidades e massas específicas: três óleos e água. Foram combinados efeitos de cinco tratamentos, sendo: meio simulante (4 níveis, espaço livre (3 níveis, freqüência de agitação (4 níveis, amplitude de agitação (2 níveis e posição das latas (4 níveis. Os ensaios de aquecimento e resfriamento foram feitos em tanque com água à temperatura de 98 °C e 17-20 °C, respectivamente. Com os dados de penetração de calor em cada experimento, foram calculados os parâmetros de penetração de calor fh, jh, fc e jc. Os resultados foram modelados utilizando-se grupos de números adimensionais e expressos em termos de Nusselt, Prandtl, Reynolds e funções trigonométricas (com medidas de amplitude e freqüência de agitação, espaço livre e dimensões da embalagem. Foram estabelecidas as duas Equações gerais para as fases de aquecimento e resfriamento: Nu = ReA –0,199.Pr –0,288.sen(xa/AM0,406.cos(xf/FA–1,039.cos((xf/FA.(EL/H.p–4,556 Aquecimento Nu = 0,1295.ReA–0,047.Pr –0,193.sen(xa/AM0,114.cos(xf/FA–0,641.cos((xf/FA.(EL/H.p–2,476 Resfriamento O processo de ALI pode ser aplicado em pasteurizadores ou autoclaves estáticas horizontais e verticais, com modificações simples. Concluiu-se que a ALI aumenta significativamente a taxa de transferência de calor, tanto no aquecimento como no resfriamento.The transient heat transfer during the intermittent and linear shaking of tin plate cans containing simulating food was studied in order to apply this technology in the pasteurization and sterilization processes, achieving

  14. Uso de transdutores de fluxo de calor no estudo da transferência de calor em alimentos embalados The use of heat flux transducers to study heat transfer in canned foods

    Directory of Open Access Journals (Sweden)

    B. Carciofi

    2002-12-01

    Full Text Available A densidade de fluxo de calor que atravessa uma superfície é classicamente determinada mediante a medição das temperaturas apropriadas e da aplicação da Lei de Fourier. Uma alternativa a esse procedimento é a utilização de transdutores de fluxo de calor, os quais geram um sinal elétrico proporcional ao fluxo térmico que os atravessa. Neste trabalho, processos de aquecimento e de resfriamento de alimentos foram estudados em laboratório, utilizando-se um recipiente de vidro cilíndrico para simular uma embalagem. Dois transdutores de fluxo de calor a gradiente tangencial foram previamente instalados no recipiente, revestindo completamente a superfície lateral do mesmo. O recipiente contendo a amostra foi inserido em banho de água circulante à temperatura constante. Os sinais fornecidos pelos transdutores e por termopares inseridos no interior do recipiente foram registrados por um sistema de aquisição de dados computadorizado. Os resultados obtidos com o uso dos transdutores foram comparados com aqueles obtidos através de balanços de energia realizados a partir dos dados experimentais de evolução temporal das temperaturas da amostra junto à superfície interna da embalagem e no centro da mesma. A comparação mostrou que os transdutores de fluxo de calor a gradiente tangencial puderam determinar os fluxos de calor, com tempo de resposta característico dos termopares. Os resultados apresentados mostraram a viabilidade de utilização desses fluxímetros no estudo não destrutivo e não invasivo dos processos de aquecimento e de resfriamento de alimentos, fornecendo informações complementares àquelas obtidas pelo uso de termopares instalados no interior da embalagem.Heat flux determination in thermal processes is classically carried out by appropriate temperature measurements and the application of the Fourier Law. An alternative to this procedure is to determine the heat flux that crosses a surface using heat flux

  15. Formation of S-(carboxymethyl)-cysteine in rat liver mitochondrial proteins: effects of caloric and methionine restriction.

    Science.gov (United States)

    Naudí, Alba; Jové, Mariona; Cacabelos, Daniel; Ayala, Victoria; Cabre, Rosanna; Caro, Pilar; Gomez, José; Portero-Otín, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-02-01

    Maillard reaction contributes to the chemical modification and cross-linking of proteins. This process plays a significant role in the aging process and determination of animal longevity. Oxidative conditions promote the Maillard reaction. Mitochondria are the primary site of oxidants due to the reactive molecular species production. Mitochondrial proteome cysteine residues are targets of oxidative attack due to their specific chemistry and localization. Their chemical, non-enzymatic modification leads to dysfunctional proteins, which entail cellular senescence and organismal aging. Previous studies have consistently shown that caloric and methionine restrictions, nutritional interventions that increase longevity, decrease the rate of mitochondrial oxidant production and the physiological steady-state levels of markers of oxidative damage to macromolecules. In this scenario, we have detected S-(carboxymethyl)-cysteine (CMC) as a new irreversible chemical modification in mitochondrial proteins. CMC content in mitochondrial proteins significantly correlated with that of the lysine-derived analog N (ε)-(carboxymethyl)-lysine. The concentration of CMC is, however, one order of magnitude lower compared with CML likely due in part to the lower content of cysteine with respect to lysine of the mitochondrial proteome. CMC concentrations decreases in liver mitochondrial proteins of rats subjected to 8.5 and 25 % caloric restriction, as well as in 40 and 80 % methionine restriction. This is associated with a concomitant and significant increase in the protein content of sulfhydryl groups. Data presented here evidence that CMC, a marker of Cys-AGE formation, could be candidate as a biomarker of mitochondrial damage during aging.

  16. Searching the conditions for a table-like shape of the magnetic entropy in magneto-caloric materials

    Energy Technology Data Exchange (ETDEWEB)

    Álvarez, Pablo, E-mail: pablo.alvarez@ehu.es [Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa (Spain); Departamento de Física, Universidad de Oviedo, c/ Calvo Sotelo, s/n, 33007 Oviedo (Spain); Gorria, Pedro, E-mail: pgorria@uniovi.es [Departamento de Física, Universidad de Oviedo, c/ Calvo Sotelo, s/n, 33007 Oviedo (Spain); Sánchez Llamazares, José L. [División de Materiales Avanzados, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la presa San José 2055, CP 78216 San Luis Potosí (Mexico); Blanco, Jesús A. [Departamento de Física, Universidad de Oviedo, c/ Calvo Sotelo, s/n, 33007 Oviedo (Spain)

    2013-08-15

    Highlights: •The magnetic entropy change for two-ribbon (amorphous) composite materials is investigated. •The conditions to obtain a table-like shape of the magnetic entropy change are specified. •We give the essential ingredients to maximize the effective refrigerant capacity and the efficiency. •Our findings could be used in other magneto-caloric materials to tune the temperature range for the table-like behavior. -- Abstract: We show a systematic study of the magneto-caloric response carried out on a series of FeZrB(Cu) amorphous ribbons with different Curie temperature values in the 210–320 K interval. The main aim of the work is to investigate the conditions to obtain, from the isothermal magnetic entropy change vs. temperature curves, ΔS{sub M}(T), a table-like behavior of the entropy using two-ribbon composites. Even though the maximum value of ΔS{sub M} for the composite is lower than those of the single components, the existence of a table-like behavior maximizes the effective refrigerant capacity, reaching values around 80 J/kg for an applied magnetic field change of 2 T. Furthermore, we discuss how the temperature range for such a table-like behavior can be tuned and the refrigerant capacity enhanced in terms of energy efficiency.

  17. The Concept of Caloric Unequal Exchange and Its Relevance for Food System Analysis: The Ecuador Case Study

    Directory of Open Access Journals (Sweden)

    Jesús Ramos-Martín

    2017-11-01

    Full Text Available The impact of food production patterns and food supply upon consumption patterns is usually explained by economies of scale and affordability. Less attention is given to food trade patterns and global insertion of economies affecting dietary changes. This paper contributes to the discussion using the concept of caloric unequal exchange that defines the deterioration of terms of trade in food in units of calories and complements studies on unequal exchange and ecologically unequal exchange. A new perspective to food systems’ analysis is achieved by using this concept. This paper uses the case study of Ecuador to exemplify its potentiality. Exports and imports to and from Ecuador are analyzed for the period 1988 through 2013 in volume, value, and calories, for different groups of products. The conclusion is that Ecuador is increasingly helping to feed the world, at a caloric cost that is decreasing over time. There is a deterioration of the terms of trade of traded food in terms of calories for Ecuador of more than 250% between 1986 and 2013.

  18. Modelo matemático de la transferencia de calor para predecir el perfil de durezas en probetas Jominy

    Directory of Open Access Journals (Sweden)

    López, E.

    2013-04-01

    Full Text Available The heat transfer coefficient was estimated at the bottom surface at Jominy bar end quench specimen by solution of the heat inverse conduction problem. A mathematical model based on the finite-difference method was developed to predict thermal paths and volume fraction of transformed phases. The mathematical model was codified in the commercial package Microsoft Visual Basic v. 6. The calculated thermal path and final phase distribution were used to evaluate the hardness distribution along the AISI 4140 Jominy bar.En el presente trabajo se estimó el coeficiente de transferencia de calor en la superficie que se encuentra en contacto con el chorro de agua en la probeta Jominy mediante la solución del problema inverso de conducción de calor. Con el objetivo de predecir los perfiles térmicos y las fracciones de fase transformadas se formuló un modelo matemático con el método de diferencias finitas y se codificó en el software comercial Microsoft Visual Basic v. 6. Los perfiles térmicos y las fracciones de fase calculadas se utilizaron para predecir el perfil de durezas en una probeta Jominy de acero AISI 4140 mediante el uso de correlaciones empíricas.

  19. Modelo matemático para la descripción de la transferencia de calor para tierra vertida

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez-Domínguez

    2014-01-01

    Full Text Available La arquitectura de tierra implica procesos constructivos sustentables ya que utiliza materiales vernáculos duraderos cuyos residuos son de bajo impacto al ambiente. La tierra vertida es una técnica a partir de la cual pueden tenerse muros resistentes dentro de la edificación de viviendas pero cuyas propiedades han sido poco evaluadas y representadas a partir de modelos. La transferencia de calor es una de las características más importantes cuando se edifica en zonas calurosas pues implica ciertos niveles de confort para los usuarios. El presente trabajo propone un modelo para determinar la difusividad térmica de tierra vertida con uso potencial para otras determinaciones a diversas temperaturas, algunas implicaciones también son presentadas. Se encontró que el coeficiente de difusividad térmica de muestras de tierra vertida fue de   4.319  10 8 m 2 s 1 , mientras que su calor específico es de 1.1030 kJkg-1K 1 .

  20. High-Caloric and Chocolate Stimuli Processing in Healthy Humans: An Integration of Functional Imaging and Electrophysiological Findings

    Science.gov (United States)

    Asmaro, Deyar; Liotti, Mario

    2014-01-01

    There has been a great deal of interest in understanding how the human brain processes appetitive food cues, and knowing how such cues elicit craving responses is particularly relevant when current eating behavior trends within Westernized societies are considered. One substance that holds a special place with regard to food preference is chocolate, and studies that used functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) have identified neural regions and electrical signatures that are elicited by chocolate cue presentations. This review will examine fMRI and ERP findings from studies that used high-caloric food and chocolate cues as stimuli, with a focus on responses observed in samples of healthy participants, as opposed to those with eating-related pathology. The utility of using high-caloric and chocolate stimuli as a means of understanding the human reward system will also be highlighted, as these findings may be particularly important for understanding processes related to pathological overeating and addiction to illicit substances. Finally, research from our own lab that focused on chocolate stimulus processing in chocolate cravers and non-cravers will be discussed, as the approach used may help bridge fMRI and ERP findings so that a more complete understanding of appetitive stimulus processing in the temporal and spatial domains may be established. PMID:24434747

  1. Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study.

    Directory of Open Access Journals (Sweden)

    Grazia Fernanda Spitoni

    Full Text Available Central post-stroke pain is a neuropathic syndrome characterized by intolerable contralesional pain and, in rare cases, somatic delusions. To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain. Resting-state functional magnetic resonance imaging was used to assess the neurological effects of this treatment. Following vestibular stimulation we observed impressive improvements in motor skills, pain, and somatic delusions. In the functional connectivity study before the vestibular stimulation, we observed differences in the patient's left thalamus functional connectivity, with respect to the thalamus connectivity of a control group (N = 20, in the bilateral cingulate cortex and left insula. After the caloric stimulation, the left thalamus functional connectivity with these regions, which are known to be involved in the cortical response to pain, disappeared as in the control group. The beneficial use of vestibular stimulation in the reduction of pain and somatic delusion in a CPSP patient is now documented by behavioral and imaging data. This evidence can be applied to theoretical models of pain and body delusions.

  2. Behavioural improvement in a minimally conscious state after caloric vestibular stimulation: evidence from two single case studies.

    Science.gov (United States)

    Vanzan, Serena; Wilkinson, David; Ferguson, Heather; Pullicino, Patrick; Sakel, Mohamed

    2017-04-01

    To investigate whether caloric vestibular stimulation, a non-invasive form of neuro-modulation, alters the level of awareness in people residing in a minimally conscious state. Single-case ( n = 2), prospective, controlled (ABAB) efficacy study. Tertiary, neuro-rehabilitation inpatient ward within a university hospital. Two individuals in a minimally conscious state. Left ear caloric vestibular stimulation was performed in two four/five-week blocks interleaved with two four/five-week blocks of sham stimulation. Session duration and frequency gradually increased within each block from once per day for 10 minutes (Week 1) to once per day for 20 minutes (Week 2) to 20 minutes twice per day in the remaining weeks. Wessex Head Injury Matrix, JFK Coma Recovery Scale - Revised. Both participants' Wessex Head Injury Matrix scores indicated a transition from involuntary (i.e. mechanical vocalization) to voluntary (i.e. gesture making, selective responses to family members) behaviour that was time-locked to the onset of active stimulation. In one participant, this improvement persisted for at least four weeks after active stimulation, while in the other it diminished two weeks after stimulation. Allied, although less dramatic, changes were seen on the arousal and auditory subscales of the JFK Coma Recovery Scale - Revised. The data provide the first evidence that vestibular stimulation may help improve outcome in a low awareness state, although further studies are needed to replicate effect and determine longer-term benefit.

  3. Role of VMH ketone bodies in adjusting caloric intake to increased dietary fat content in DIO and DR rats.

    Science.gov (United States)

    Le Foll, Christelle; Dunn-Meynell, Ambrose A; Miziorko, Henry M; Levin, Barry E

    2015-05-15

    The objective of this study was to determine the potential role of astrocyte-derived ketone bodies in regulating the early changes in caloric intake of diet induced-obese (DIO) versus diet-resistant (DR) rats fed a 31.5% fat high-energy (HE) diet. After 3 days on chow or HE diet, DR and DIO rats were assessed for their ventromedial hypothalamic (VMH) ketone bodies levels and neuronal ventromedial hypothalamic nucleus (VMN) sensing using microdialysis coupled to continuous food intake monitoring and calcium imaging in dissociated neurons, respectively. DIO rats ate more than DR rats over 3 days of HE diet intake. On day 3 of HE diet intake, DR rats reduced their caloric intake while DIO rats remained hyperphagic. Local VMH astrocyte ketone bodies production was similar between DR and DIO rats during the first 6 h after dark onset feeding but inhibiting VMH ketone body production in DR rats on day 3 transiently returned their intake of HE diet to the level of DIO rats consuming HE diet. In addition, dissociated VMN neurons from DIO and DR rats were equally sensitive to the largely excitatory effects of β-hydroxybutyrate. Thus while DR rats respond to increased VMH ketone levels by decreasing their intake after 3 days of HE diet, this is not the case of DIO rats. These data suggest that DIO inherent leptin resistance prevents ketone bodies inhibitory action on food intake.

  4. High-Caloric and Chocolate Stimuli Processing in Healthy Humans: An Integration of Functional Imaging and Electrophysiological Findings

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    Deyar Asmaro

    2014-01-01

    Full Text Available There has been a great deal of interest in understanding how the human brain processes appetitive food cues, and knowing how such cues elicit craving responses is particularly relevant when current eating behavior trends within Westernized societies are considered. One substance that holds a special place with regard to food preference is chocolate, and studies that used functional magnetic resonance imaging (fMRI and event-related potentials (ERPs have identified neural regions and electrical signatures that are elicited by chocolate cue presentations. This review will examine fMRI and ERP findings from studies that used high-caloric food and chocolate cues as stimuli, with a focus on responses observed in samples of healthy participants, as opposed to those with eating-related pathology. The utility of using high-caloric and chocolate stimuli as a means of understanding the human reward system will also be highlighted, as these findings may be particularly important for understanding processes related to pathological overeating and addiction to illicit substances. Finally, research from our own lab that focused on chocolate stimulus processing in chocolate cravers and non-cravers will be discussed, as the approach used may help bridge fMRI and ERP findings so that a more complete understanding of appetitive stimulus processing in the temporal and spatial domains may be established.

  5. Resveratrol and caloric restriction prevent hepatic steatosis by regulating SIRT1-autophagy pathway and alleviating endoplasmic reticulum stress in high-fat diet-fed rats.

    Science.gov (United States)

    Ding, Shibin; Jiang, Jinjin; Zhang, Guofu; Bu, Yongjun; Zhang, Guanghui; Zhao, Xiangmei

    2017-01-01

    Studies have demonstrated that resveratrol (a natural polyphenol) and caloric restriction activate Sirtuin-1 (SIRT1) and induce autophagy. Furthermore, autophagy is induced by the SIRT1-FoxO signaling pathway and was recently shown to be a critical protective mechanism against non-alcoholic fatty liver disease (NAFLD) development. We aimed to compare the effects of resveratrol and caloric restriction on hepatic lipid metabolism and elucidate the mechanism by which resveratrol supplementation and caloric restriction alleviate hepatosteatosis by examining the molecular interplay between SIRT1 and autophagy. Eight-week-old male Wistar rats (40) were divided into four groups: the STD group, which was fed a standard chow diet; the HFD group, which was fed a high-fat diet; HFD-RES group, which was fed a high-fat diet plus resveratrol (200 mg/kg.bw); and the HFD-CR group, which was fed a high-fat diet in portions containing 70% of the mean intake of the HFD group rats. The groups were maintained for 18 weeks. Metabolic parameters, Oil Red O and hematoxylin-eosin staining of the liver, and the mRNA and protein expression of SIRT1, autophagy markers and endoplasmic reticulum(ER) stress-associated genes in the liver were assessed after the 18-week treatment. We found that resveratrol (200 mg/kg bw) and caloric restriction (30%) partially prevented hepatic steatosis and hepatocyte ballooning, increased the expression of SIRT1 and autophagy markers while decreasing ER stress markers in the liver and alleviated lipid metabolism disorder. Moreover, caloric restriction provided superior protection against HFD-induced hepatic fatty accumulation compared with resveratrol and the effects were associated with decreased total energy intake and body weight. We conclude that the SIRT1-autophagy pathway and decreased ER stress are universally required for the protective effects of moderate caloric restriction (30%) and resveratrol (a pharmacological SIRT1 activator) supplementation

  6. Comparison of Intermittent Fasting Versus Caloric Restriction in Obese Subjects: A Two Year Follow-Up.

    Science.gov (United States)

    Aksungar, F B; Sarıkaya, M; Coskun, A; Serteser, M; Unsal, I

    2017-01-01

    Caloric restriction (CR) is proven to be effective in increasing life span and it is well known that, nutritional habits, sleeping pattern and meal frequency have profound effects on human health. In Ramadan some Muslims fast during the day-light hours for a month, providing us a unique model of intermittent fasting (IF) in humans. In the present study, we have investigated the effects of IF versus CR on the same non-diabetic obese subjects who were followed for two years according to the growth hormone (GH)/Insulin like growth factor (IGF)-1 axis and insulin resistance. Single-arm Interventional Human Study. 23 female subjects (Body Mass Index (BMI) 29-39, aged between 28-42years). Follow-up is designed as 12 months of CR, after which there was a month of IF and 11 months of CR again, to be totally 24 months. Subjects' daily diets were aligned as low calorie diet during CR and during the IF period, the same subjects fasted for 15 hours in a day for a month and there was no daily calorie restriction. Nutritional pattern was changed as 1 meal in the evening and a late supper before sleeping and no eating and drinking during the day light hours in the IF model. Subjects made brisk walking twice a day during the whole follow-up including both CR and IF periods. BMI, Blood glucose, insulin, TSH, GH, HbA1c, IGF-1, Homa-IR and urinary acetoacetate levels were monitored once in three months and twice in the fasting month. While subjects lost 1250 ± 372g monthly during the CR, in the IF period, weight loss was decreased to 473 ± 146 g. BMI of all subjects decreased gradually and as the BMI decreased, glucose, HbA1c, insulin, Homa-IR and TSH levels were decreased. GH levels were at baseline at the beginning, increased in the first six months and stayed steady during the CR and IF period than began decreasing after the IF period, while IGF-I increased gradually during the CR period and beginning with the 7th day of IF period, it decreased and kept on decreasing till the

  7. DESHIDRATACION Y SOBREHIDRATACION VOLUNTARIAS DURANTE EL EJERCICIO EN EL CALOR: POSIBLES FACTORES RELACIONADOS

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    Andrea Solera Herrera

    2006-12-01

    Full Text Available Los efectos negativos de la deshidratación sobre la salud y el rendimiento han sido bien documentados. Recientemente, también se han documentado problemas por sobrehidratación. La presente investigación se hizo para estudiar los posibles factores que influyen sobre la ingesta voluntaria de líquido durante el ejercicio y determinar si existe relación entre el grado de deshidratación voluntaria y la creencia de que la ingesta de líquido provoca cólico. Para ello, se contó con 94 estudiantes universitarios jóvenes, varones, quienes se ejercitaron a un 60% de su FCmáx durante una hora, alternando cada 10 min. entre bicicleta estacionaria, subir y bajar un escalón, y una máquina simuladora de esquí. Esto se realizó en un laboratorio de ambiente controlado a 30úC, 70% humedad relativa. Durante el ejercicio se midió la ingesta voluntaria de una bebida deportiva, así como también las percepciones de calor ambiental, llenura estomacal, malestar gastrointestinal y palatabilidad de la bebida. Los sujetos fueron pesados desnudos y secos antes y después del ejercicio. Al final se les aplicó un cuestionario sobre la importancia de la hidratación, y sus creencias sobre el cólico. El equilibrio hídrico promedio fue de 0.14 ± 0.98% del peso corporal, con un rango entre -2.38% y 2.84%. La tasa de sudoración promedio fue de 1208.3 ± 381.7ml·h-1; y la ingesta de 1132 ± 610ml·h-1. Dos análisis de regresión múltiple determinaron que: (a los predictores más fuertes de la ingesta voluntaria de líquido fueron la importancia asignada a la hidratación durante el ejercicio (R2 = 0.13; p < 0.0005 y la percepción de llenura estomacal al minuto 25 (R2 = 0.08; p = 0.005; (b los predictores más fuertes del equilibrio hídrico fueron la ingesta voluntaria por kg de peso (R2 = 0.73; p < 0.0005, y la tasa de sudoración (R2 = 0.08; p = 0.006. No obstante, el equilibrio hídrico no estuvo asociado con ninguna de las percepciones, ni con las

  8. Transferencia de calor y su efecto en el proceso de prensado de tableros contrachapados

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    D. Zavala Zavala

    2004-01-01

    Full Text Available El proceso de prensado determina la calidad de los contrachapados (triplay a través de la interrelación de las propiedades tecnológicas de la madera, de las características de los adhesivos y de la interacción de la temperatura y presión que se generan en la prensa. Este trabajo se realizó con la finalidad de analizar el efecto de la transferencia de calor en la polimerización de adhesivos preparados con urea y fenol formaldehído, para determinar la secuela optima de prensado de triplay de 6, 9, 12, 15, 18 y 34 mm de espesor; y para evaluar la compactación de los tableros por efecto de la temperatura y presión durante el prensado. Se utilizó chapa de Pinus herrerai Martínez, P. michoacana Martínez y P. pseudostrobus Lindl., a un contenido de humedad de 6 a 8 %, una prensa calentada con vapor, adhesivo de urea formaldehído para tableros para interiores de 6, 9, 12, 15 y 18 mm y fenol formaldehído para triplay para exteriores de 34 mm de espesor. Se utilizaron ciclos de prensado aplicando temperaturas de 115, 130 y 140 °C y presiones de 10.62 kg·cm-2 (151 psi y 8.51 kg·cm-2 (121 psi en triplay para interiores, y para los tableros tipo exterior de 140, 150 y 160 °C de temperatura y 12.23, 13.29 y 14.34 kg·cm-2 (174, 189 y 204 psi de presión. La temperatura de las líneas de pegamento más externas aumenta rápidamente al cerrarse la prensa y manifiesta una diferencia en relación a las más internas, que tiende a reducirse conforme transcurre el tiempo de prensado, igualándose aproximadamente al 73 % del tiempo para cada tipo de tablero. A través de la evaluación de adhesión de los pegamentos de los tableros para interiores con la norma PS1-95, se determinó que todos pasan las especificaciones requeridas para ese uso En los tableros de 34 mm de espesor, con un incremento de la temperatura de 140 a 160 °C, una presión de 12.23 a 14.34 kg·cm-2 (174 a 204 psi y un contenido de sólidos del fenol formaldehído de 29.9 a 32

  9. Análise teórica e experimental do comportamento de um trocador de calor geotérmico

    OpenAIRE

    Martins, William Marques

    2015-01-01

    Este trabalho apresenta um estudo teórico e experimental de um trocador de calor geotérmico, tipo helicoidal água-solo, para uso como condensador em um sistema de ar condicionado. Para o experimento foi construída uma bancada composta basicamente por um reservatório térmico, uma bomba d’água, medidor de vazão, um trocador de calor com serpentina tipo helicoidal com comprimento e diâmetro de 3 e 0,27 m, respectivamente e enterrado verticalmente no solo no sentido do comprimento. Foi utilizado ...

  10. Estudo da transferência de calor durante o congelamento de cortes de aves em caixas de papelão ondulado

    OpenAIRE

    Santos, Clarice de Ávila

    2005-01-01

    Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia de Alimentos O congelamento de produtos alimentícios é um processo complexo que envolve transferência de calor com mudança de fase e ocorre em uma faixa de temperaturas. É realizado, predominantemente, em túneis com convecção forçada de ar, onde o escoamento de ar ocorre em regime turbulento e a transferência de calor do produto para o ar em regime transiente. Quando...

  11. Modelado de dinámica de fluidos y transferencia de calor y masa en procesos agroalimentarios por método de volúmenes finitos

    OpenAIRE

    Moraga, Nelson O.; ZAMBRA, CARLOS E.; PAUL B. TORRES; ROBERTO A. LEMUS-MONDACA

    2011-01-01

    Se describe la transferencia de momento, calor y masa transiente bi-dimensional en procesos agroalimentarios. Estos procesos son: la pre-cosecha y luego la deshidratación por aire caliente de frutas. La metodología incluye modelación matemática y simulación computacional para describir la convección y difusión de calor y masa conjugada que resulta de la interacción entre el alimento y el aire. El modelo matemático emplea las ecuaciones diferenciales parciales no lineales acopladas de continu...

  12. La ola de calor de 2003 en España, entre la realidad biofísica y el reconocimiento mediático

    OpenAIRE

    Fernández Reyes, Rogelio

    2012-01-01

    Globalización Media permite medios de comunicación para cubrir desastres naturales en una forma mucho más eficaz. Hoy, muchos de esos desastres están relacionados con el cambio climático. Sin embargo, en agosto de 2003, mientras que la ola de calor se estaba produciendo en España apenas existen voces conectadas al cambio climático. Algunos científicos argumentan que no podemos afirmar la ola de calor en 2003 fue causado por el cambio climático. Pero también hay investigaciones y referencias q...

  13. Desenvolvimento, validação e aplicação de um transdutor de fluxo de calor poroso em desconforto térmico /

    OpenAIRE

    Silva, Jesué Graciliano da

    1999-01-01

    Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Em grande parte do Brasil, predomina o trabalho em temperaturas elevadas. Nestas circunstâncias a necessidade de um trabalhador liberar calor para o ambiente é suprida principalmente pela evaporação do suor. Neste trabalho, estuda-se as trocas de calor e massa na interface entre o homem e o ambiente. Para tanto, procurou-se reproduzir as condições da interface através de uma bancada experimental. Neste a...

  14. Estudio sobre los efectos de campo acústico en la transmisión de calor de un calentador de aire de admisión

    OpenAIRE

    RAMÍREZ CARDONA, MARÍA ISABEL

    2015-01-01

    Se ha documentado que la presencia de ondas acústicas puede influir sobre la transferencia de calor, a través de las modificaciones producidas por las ondas en la capa límite. Esta opción presenta a priori ventajas sobre otras formas de mejora de la transferencia de calor, como la corrugación de superficies, ya que su influencia sobre la pérdida de carga es menor y el requerimiento energético es marginal comparado con el del calentador mismo. Se pretende por ello estudiar el potencial de mejo...

  15. Syagrus schizophylla: Unconventional Food Plant of the Caatinga Biome with a high caloric value | Syagrus schizophylla: Planta alimentícia não convencional do bioma de caatinga com alto valor calórico

    Directory of Open Access Journals (Sweden)

    Maria do Rosário Fátima Padilha

    2017-06-01

    Full Text Available In the present day world concern relates to the effects of climate on plantations. In various parts of the world, forests, fields, plantations continue to disappear or are degraded. Brazil is a country that concentrates a great diversity of plants, this also refers to the Caatinga biome that participates in the vegetal cover of the state of Pernambuco, where this vegetation still displays the presence of unconventional food plants (UFP. Seeking to know in more detail the nutritional value of fruits of the palm Syagrus schizophylla known as Catolé coconut, this study sought to assess the centesimal composition of its almonds. Physico-chemical tests were performed in triplicate and according to methodologies of Instituto Adolfo Lutz-IAL. Before the results, it is concluded that the Catolé coconut almond is very nutritious and presents high caloric value.

  16. Respostas pós-colheita de abacaxi 'Pérola' no tratamento com calor e armazenagem refrigerada

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    Rosilene Ferreira Souto

    2014-12-01

    Full Text Available Este trabalho teve como objetivo avaliar o efeito de diferentes temperaturas de armazenamento e do tratamento inicial a 40 ºC, por 24 horas, na preservação de abacaxis 'Pérola'. Os abacaxis foram colhidos no estádio de maturação "pintado", tratados com calor e foram mantidos sob condição de ambiente (25 ºC e 75-80% UR ou refrigerados durante 17 dias, a 8 ºC, ou 14 ºC. Após este período, foram transferidos para condição de ambiente, 25 ºC e 75-80% UR. As avaliações foram realizadas no início (0 dia e após 1; 5; 9; 13 ou 17 dias. Os frutos armazenados sob refrigeração foram transferidos para o ambiente e também foram avaliados aos 21, 25 ou 29 dias. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial (2x3x9, tendo-se os fatores, frutos tratados com calor ou não, três temperaturas de armazenamento e 9 épocas de avaliação. Os frutos foram avaliados quanto à perda de massa fresca, coloração externa, resistência da casca e da polpa, rendimento em polpa, além da intensidade respiratória. A perda de massa fresca e a resistência da casca e da polpa foram maiores nos frutos armazenados sob condição ambiente quando comparada à perda de massa e resistência dos abacaxis armazenados sob refrigeração, com variação na coloração da casca, de verde para amarela, com a evolução do tempo. Os abacaxis mantidos sob refrigeração a 8 ºC ou 14 ºC tiveram vida útil de 29 dias, enquanto os abacaxis mantidos a 25 ºC foram descartados após 17 dias. Abacaxis tratados com calor apresentaram a maior taxa respiratória, enquanto aqueles mantidos a 8 ºC apresentaram a menor atividade respiratória, tanto sob refrigeração como em condição ambiente.

  17. Perda de calor determinada pela exposição das alças intestinais em ratos

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    Luiz Carlos Von Bahten

    Full Text Available OBJETIVO: Esta pesquisa tem por objetivo quantificar a perda de energia calórica que ocorre ao realizarmos uma laparotomia com exposição de alças intestinais à atmosfera em ratos; determinar a perda termodinâmica representada por watts/m² em função da superfície peritoneal exposta do animal e discutir meios de tratamento para a perda de calor. MÉTODO: Foram utilizados 30 ratos machos, Wistar, distribuídos em cinco grupos de seis animais cada, com idade de 8 a 9 semanas, com o peso entre 200 e 220g. No grupo A ou grupo controle, os animais foram submetidos a anestesia inalatória. No grupo B, os ratos foram submetidos a uma laparotomia mediana com exposição das alças intestinais. Nos grupos C, D e E, os ratos foram submetidos a uma laparotomia mediana com exposição das alças intestinais e tratados respectivamente, por gaze úmida, gaze seca e empacotamento com filme de poliéster. RESULTADOS: Observou-se uma significativa perda de energia calórica quando se realiza uma laparotomia com exposição das alças intestinais em ambiente não controlado, da ordem de 620,72 kJ/m² A análise da perda termodinâmica, em função da superfície corpórea exposta do rato, apresentou um valor de 382,97 W/m². CONCLUSÕES: Na avaliação dos diferentes tipos de tratamento utilizados para prevenir a perda de calor corpóreo, ficou evidente que a utilização do filme de poliéster (PVC foi o método mais efetivo na conservação do calor, em relação à gaze seca e, ou úmida respectivamente.

  18. Caloric compensation and eating in the absence of hunger in 5- to 12-y-old weight-discordant siblings123

    Science.gov (United States)

    Kral, Tanja VE; Allison, David B; Birch, Leann L; Stallings, Virginia A; Moore, Reneé H; Faith, Myles S

    2012-01-01

    Background: An impaired ability to compensate for calories and increased eating in the absence of hunger (EAH) has been associated with increased energy intake and weight gain in unrelated children. Objective: The aims of this study were to compare caloric compensation [the percentage compensation index (%COMPX)] and EAH in weight-discordant siblings aged 5–12 y. Design: In a crossover, behavioral genetics design, 47 same-sex sibling pairs (53% female, 55% full siblings) were served dinner once a week for 3 wk. Across conditions, siblings were served the same dinner, but 25 min before dinner, they either consumed in full or did not consume 1 of 2 preloads that varied in energy density (ED; 0.57 or 0.97 kcal/g). On the day when no preload was consumed, EAH was assessed after dinner and defined as the number of calories consumed from snacks. Results: Overweight/obese siblings undercompensated [%COMPX: −48.8 ± 56.3 (mean ± SEM)] and therefore overate after the high-ED preload, whereas normal-weight siblings showed accurate compensation (%COMPX: 101.3 ± 51.9; P = 0.03). Furthermore, overweight/obese siblings consumed 34% more calories (93 kcal) in the absence of hunger than did normal-weight siblings (P = 0.01). Within-pair resemblances for %COMPX and EAH were stronger for full siblings (P siblings (P > 0.23). Conclusions: An impaired ability to regulate short-term energy intake, which includes incomplete adjustment for calorie differences in a preload and eating when satiated, may represent a behavioral phenotype for obesity in children. Future studies should test whether teaching children to focus on internal satiety cues may prevent at-risk children from overeating. This trial was registered at clinicaltrials.gov as NCT01598389. PMID:22854400

  19. Management of multifactorial idiopathic epilepsy in EL mice with caloric restriction and the ketogenic diet: role of glucose and ketone bodies

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    Mantis John G

    2004-10-01

    Full Text Available Abstract Background The high fat, low carbohydrate ketogenic diet (KD was developed as an alternative to fasting for seizure management. While the mechanisms by which fasting and the KD inhibit seizures remain speculative, alterations in brain energy metabolism are likely involved. We previously showed that caloric restriction (CR inhibits seizure susceptibility by reducing blood glucose in the epileptic EL mouse, a natural model for human multifactorial idiopathic epilepsy. In this study, we compared the antiepileptic and anticonvulsant efficacy of the KD with that of CR in adult EL mice with active epilepsy. EL mice that experienced at least 15 recurrent complex partial seizures were fed either a standard diet unrestricted (SD-UR or restricted (SD-R, and either a KD unrestricted (KD-UR or restricted (KD-R. All mice were fasted for 14 hrs prior to diet initiation. A new experimental design was used where each mouse in the diet-restricted groups served as its own control to achieve a 20–23% body weight reduction. Seizure susceptibility, body weights, and the levels of plasma glucose and β-hydroxybutyrate were measured once/week over a nine-week treatment period. Results Body weights and blood glucose levels remained high over the testing period in the SD-UR and the KD-UR groups, but were significantly (p Conclusions The results indicate that seizure susceptibility in EL mice is dependent on plasma glucose levels and that seizure control is more associated with the amount than with the origin of dietary calories. Also, CR underlies the antiepileptic and anticonvulsant action of the KD in EL mice. A transition from glucose to ketone bodies for energy is predicted to manage EL epileptic seizures through multiple integrated changes of inhibitory and excitatory neural systems.

  20. Metabolically distinct weight loss by 10,12 CLA and caloric restriction highlight the importance of subcutaneous white adipose tissue for glucose homeostasis in mice.

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    Laura J den Hartigh

    Full Text Available Widely used as a weight loss supplement, trans-10,cis-12 conjugated linoleic acid (10,12 CLA promotes fat loss in obese mice and humans, but has also been associated with insulin resistance.We therefore sought to directly compare weight loss by 10,12 CLA versus caloric restriction (CR, 15-25%, an acceptable healthy method of weight loss, to determine how 10,12 CLA-mediated weight loss fails to improve glucose metabolism.Obese mice with characteristics of human metabolic syndrome were either supplemented with 10,12 CLA or subjected to CR to promote weight loss. Metabolic endpoints such as energy expenditure, glucose and insulin tolerance testing, and trunk fat distribution were measured.By design, 10,12 CLA and CR caused equivalent weight loss, with greater fat loss by 10,12 CLA accompanied by increased energy expenditure, reduced respiratory quotient, increased fat oxidation, accumulation of alternatively activated macrophages, and browning of subcutaneous white adipose tissue (WAT. Moreover, 10,12 CLA-supplemented mice better defended their body temperature against a cold challenge. However, 10,12 CLA concurrently induced the detrimental loss of subcutaneous WAT without reducing visceral WAT, promoted reduced plasma and WAT adipokine levels, worsened hepatic steatosis, and failed to improve glucose metabolism. Obese mice undergoing CR were protected from subcutaneous-specific fat loss, had improved hepatic steatosis, and subsequently showed the expected improvements in WAT adipokines, glucose metabolism and WAT inflammation.These results suggest that 10,12 CLA mediates the preferential loss of subcutaneous fat that likely contributes to hepatic steatosis and maintained insulin resistance, despite significant weight loss and WAT browning in mice. Collectively, we have shown that weight loss due to 10,12 CLA supplementation or CR results in dramatically different metabolic phenotypes, with the latter promoting a healthier form of weight loss.

  1. Metabolic Benefit of Chronic Caloric Restriction and Activation of Hypothalamic AGRP/NPY Neurons in Male Mice Is Independent of Ghrelin

    Science.gov (United States)

    Rogers, Nicole H.; Walsh, Heidi; Alvarez-Garcia, Oscar; Park, Seongjoon; Gaylinn, Bruce; Thorner, Michael O.

    2016-01-01

    Aging is associated with attenuated ghrelin signaling. During aging, chronic caloric restriction (CR) produces health benefits accompanied by enhanced ghrelin production. Ghrelin receptor (GH secretagogue receptor 1a) agonists administered to aging rodents and humans restore the young adult phenotype; therefore, we tested the hypothesis that the metabolic benefits of CR are mediated by endogenous ghrelin. Three month-old male mice lacking ghrelin (Ghrelin−/−) or ghrelin receptor (Ghsr−/−), and their wild-type (WT) littermates were randomly assigned to 2 groups: ad libitum (AL) fed and CR, where 40% food restriction was introduced gradually to allow Ghrelin−/− and Ghsr−/− mice to metabolically adapt and avoid severe hypoglycemia. Twelve months later, plasma ghrelin, metabolic parameters, ambulatory activity, hypothalamic and liver gene expression, as well as body composition were measured. CR increased plasma ghrelin and des-acyl ghrelin concentrations in WT and Ghsr−/− mice. CR of WT, Ghsr−/−, and Ghrelin−/− mice markedly improved metabolic flexibility, enhanced ambulatory activity, and reduced adiposity. Inactivation of Ghrelin or Ghsr had no effect on AL food intake or food anticipatory behavior. In contrast to the widely held belief that endogenous ghrelin regulates food intake, CR increased expression of hypothalamic Agrp and Npy, with reduced expression of Pomc across genotypes. In the AL context, ablation of ghrelin signaling markedly inhibited liver steatosis, which correlated with reduced Pparγ expression and enhanced Irs2 expression. Although CR and administration of GH secretagogue receptor 1a agonists both benefit the aging phenotype, we conclude the benefits of chronic CR are a consequence of enhanced metabolic flexibility independent of endogenous ghrelin or des-acyl ghrelin signaling. PMID:26812158

  2. The influence of caloric deprivation and food composition on TSH, thyroid hormones and nuclear binding of T3 in mononuclear blood cells in obese women

    DEFF Research Database (Denmark)

    Matzen, L E; Kvetny, J

    1989-01-01

    In vivo changes in thyroid-stimulating hormone (TSH), thyroxin (T4), triiodothyronine (T3) and nuclear binding of T3 (NBT3) in mononuclear blood cells were studied in obese women during seven days of caloric deprivation (maximum 1,100 kcal/d). In seven women given a high protein diet (80% protein...

  3. Roles of caloric restriction, ketogenic diet and intermittent fasting during initiation, progression and metastasis of cancer in animal models: a systematic review and meta-analysis.

    Science.gov (United States)

    Lv, Mengmeng; Zhu, Xingya; Wang, Hao; Wang, Feng; Guan, Wenxian

    2014-01-01

    The role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments. However, the conclusions are controversial. We aim to review the relevant animal studies systematically and provide assistance for further clinical studies. Literatures on associations between dietary restriction and cancer published in PubMed in recent twenty years were comprehensively searched. Animal model, tumor type, feeding regimen, study length, sample size, major outcome, conclusion, quality assessment score and the interferential step of cancer were extracted from each eligible study. We analyzed the tumor incidence rates from 21 studies about caloric restriction. Fifty-nine studies were involved in our system review. The involved studies explored roles of dietary restriction during initiation, progression and metastasis of cancer. About 90.9% of the relevant studies showed that caloric restriction plays an anti-cancer role, with the pooled OR (95%CI) of 0.20 (0.12, 0.34) relative to controls. Ketogenic diet was also positively associated with cancer, which was indicated by eight of the nine studies. However, 37.5% of the related studies obtained a negative conclusion that intermittent fasting was not significantly preventive against cancer. Caloric restriction and ketogenic diet are effective against cancer in animal experiments while the role of intermittent fasting is doubtful and still needs exploration. More clinical experiments are needed and more suitable patterns for humans should be investigated.

  4. Sistemas de transmisión de calor para hornos de vía seca en la fabricación de cemento

    Directory of Open Access Journals (Sweden)

    Tonry, J. Richard

    1961-12-01

    Full Text Available Not availableEn los últimos años se han puesto en marcha numerosos sistemas para mejorar la transmisión de calor en los hornos de vía seca y, en consecuencia, el consumo de combustible en la industria del cemento. El objetivo principal ha sido el ahorro de combustible y la obtención de mayores velocidades de producción en comparación con los hornos horizontales normales. Estos sistemas pueden dividirse en dos grupos: (1 externos, donde fluyen en contracorriente sólidos y gases calientes, 71 (2 internos, con exposición de superficie y radiación de la misma como medio de transmisión de calor. Esta tendencia a sistemas de este tipo puede compararse a la que hubo hace cuarenta años con las calderas de recuperación de calor en hornos de vía seca. El primer objetivo, tanto entonces como ahora, es la mejor utilización del calor en los gases de escape.

  5. Roles of caloric restriction, ketogenic diet and intermittent fasting during initiation, progression and metastasis of cancer in animal models: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Mengmeng Lv

    Full Text Available The role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments. However, the conclusions are controversial. We aim to review the relevant animal studies systematically and provide assistance for further clinical studies.Literatures on associations between dietary restriction and cancer published in PubMed in recent twenty years were comprehensively searched. Animal model, tumor type, feeding regimen, study length, sample size, major outcome, conclusion, quality assessment score and the interferential step of cancer were extracted from each eligible study. We analyzed the tumor incidence rates from 21 studies about caloric restriction.Fifty-nine studies were involved in our system review. The involved studies explored roles of dietary restriction during initiation, progression and metastasis of cancer. About 90.9% of the relevant studies showed that caloric restriction plays an anti-cancer role, with the pooled OR (95%CI of 0.20 (0.12, 0.34 relative to controls. Ketogenic diet was also positively associated with cancer, which was indicated by eight of the nine studies. However, 37.5% of the related studies obtained a negative conclusion that intermittent fasting was not significantly preventive against cancer.Caloric restriction and ketogenic diet are effective against cancer in animal experiments while the role of intermittent fasting is doubtful and still needs exploration. More clinical experiments are needed and more suitable patterns for humans should be investigated.

  6. DETERMINACIÓN EXPERIMENTAL DE LA CANTIDAD DE CALOR EMITIDA POR UN CIRCUITO ELECTRÓNICO EXPERIMENTAL MEASUREMENT OF THE AMOUNT OF HEAT GENERATED BY AN ELECTRONIC CIRCUIT

    Directory of Open Access Journals (Sweden)

    Jeison Marín

    2012-06-01

    Full Text Available El presente artículo describe un calorímetro que en la actualidad se utiliza para la determinación experimental de la cantidad de calor generado por circuitos electrónicos con la particularidad de permitir la entrada de potencia eléctrica al circuito electrónico bajo ensayo, para poder hacer seguimiento de su dinámica de generación de calor por efecto Joule. Para ello, se construyeron varios circuitos electrónicos básicos y cuyos resultados se presentan. Se logró de esta manera disponer de un sistema que permite contrastar las predicciones teóricas realizadas por un diseñador en cuanto a la generación de calor, frente a resultados experimentales.This article describes a calorimeter created for the experimental determination of the amount of heat generated by an electronic circuit. It has the particularity of allowing the power input to the electronic circuit under experiment, with the purpose of making possible to follow its dynamic heat flows generation by Joule effect. Several simple electronic circuits were making and their results are presented. In this way, there is now available a system which allows to evaluate the proposed theoretical predictions done by a designer and related to the heat generation, against experimental results.

  7. Caloric Restriction reduces inflammation and improves T cell-mediated immune response in obese mice but concomitant consumption of curcumin/piperine adds no further benefit

    Science.gov (United States)

    Obesity is associated with low-grade inflammation and impaired immune response. Caloric restriction (CR) has been shown to inhibit inflammatory response and enhance cell-mediated immune function. Curcumin, the bioactive phenolic component of turmeric spice, is proposed to have anti-obesity and anti-...

  8. Effects of caloric restriction on learning and recovery of a spatial task in rats exposed to acute stress

    Directory of Open Access Journals (Sweden)

    Lamprea Rodríguez, Marisol

    2009-06-01

    Full Text Available The purpose of the present study was to describe the effects of caloric restriction on spatial learning and recovery in the Barnes maze in animals experimentally stressed before recovery of the spatial task. Male Wistar rats were exposed for two months to one of two conditions: ad libitum (AL or intermittent fasting (IF. Both groups were exposed then to an experimental form of acute stress, induced by movement restriction for 4 hours. IF subjects had better performance in learning tasks during the acquisition trials but required more time to complete the task after the stressor was applied. These results are discussed in light of previous data reported in the literature emphasizing differences in the instruments used to evaluate spatial learning and its interaction with experimentally induced stress.

  9. Solar thermal power plants for heat and electricity generation; Presentacion de plantas termosolares para generacion de calor y energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Estrada Cajigal, V. [Solartronic S. A. de C. V., Cuernavaca (Mexico); Manzini, F.; Sanchez, A. [Laboratorio de Energia Solar (IIM-UNAM), Temixco (Mexico)

    1992-12-31

    Solar thermal technology is presented for concentration into a point for the production of heat and energy in small and large scale, emphasis is made on the capacity for the combination with current technologies using fossil fuels for electricity generation and process steam, increasing the global efficiency of the power plants and notably reducing the pollutants emission to the air during the insolation hours. It is successfully compared with other solar-thermal technologies. [Espanol] Se presenta la tecnologia termosolar de concentracion puntual para produccion de calor y de energia en pequena y gran escala, se enfatiza su capacidad de combinacion con las tecnologias actuales que utilizan combustibles fosiles para produccion de electricidad y vapor de proceso, aumentando la eficiencia global de las plantas y reduciendo notablemente sus emisiones contaminantes a la atmosfera durante las horas de insolacion. Se le compara exitosamente con otras tecnologias termosolares.

  10. Distinct lipid profiles predict improved glycemic control in obese, nondiabetic patients after a low-caloric diet intervention

    DEFF Research Database (Denmark)

    Valsesia, Armand; Saris, Wim Hm; Astrup, Arne

    2016-01-01

    improvement. DESIGN: We investigated the plasma lipidome of 383 obese, nondiabetic patients within a randomized, controlled dietary intervention in 8 European countries at baseline, after an 8-wk low-caloric diet (LCD) (800-1000 kcal/d), and after 6 mo of weight maintenance. RESULTS: After weight loss......, a lipid signature identified 2 groups of patients who were comparable at baseline but who differed in their capacities to lose weight and improve glycemic control. Six months after the LCD, one group had significant glycemic improvement [homeostasis model assessment of insulin resistance (HOMA-IR) mean...... change: -0.92; 95% CI: -1.17, -0.67)]. The other group showed no improvement in glycemic control (HOMA-IR mean change: -0.26; 95% CI: -0.64, +0.13). These differences were sustained for ≥1 y after the LCD. The same conclusions were obtained with other endpoints (Matsuda index and fasting insulin...

  11. Humedad de equilibrio y calor latente de vaporización del ajonjolí. Sésamun indicum L.

    Directory of Open Access Journals (Sweden)

    Julio E. Ospina M.

    2011-06-01

    Full Text Available El ajonjolí (Sésamun indicum L., es una oleaginosa originaria de África y cultivada en las regiones tropicales y subtropicales de Asia y América. A los 110 días de sembrada se cosecha la semilla la cual se utiliza como materia prima especialmente en la industria de grasas y aceites comestibles. Actualmente se pierden en Colombia, un alto porcentaje de semillas durante el proceso de secado natura en el campo. Debido a la falta de información técnica, científica en secado y almacenamiento del grana de ajonjolí se procedió a estudiar la metodología para determinar, el contenido de humedad por el método de la estufa, las curvas y modelo para cuantificar la humedad de equilibrio y el calor latente de vaporización.

  12. Análisis de la dispersión axial de masa y calor en reactores de lecho fijo

    Directory of Open Access Journals (Sweden)

    Rangel Jara Hermes Augusto

    1997-01-01

    Full Text Available Dentro del espíritu investigativo a nivel teórico del estudio de los reactores químicos, el presente trabajo desarrolla e implementa un análisis conceptual y numérico de los fenómenos de dispersión axial de calor y masa en reactores de lecho fijo. Se pretende disponer de una alternativa numérica que permita en una forma rápida y precisa la solución de las ecuaciones diferenciales junto con las respectivas condiciones de frontera del modelo matemático. Para la simulación del reactor de lecho fijo se empleó un modelo unidimensional pseudohomogeneo con parámetros aglomerados.

  13. Análisis de la dispersión axial de masa y calor en reactores de lecho fijo

    Directory of Open Access Journals (Sweden)

    Rangel Jara Hermes Augusto

    2011-06-01

    Full Text Available Dentro del espíritu investigativo a nivel teórico del estudio de los reactores químicos, el presente trabajo desarrolla e implementa un análisis conceptual y numérico de los fenómenos de dispersión axial de calor y masa en reactores de lecho fijo. Se pretende disponer de una alternativa numérica que permita en una forma rápida y precisa la solución de las ecuaciones diferenciales junto con las respectivas condiciones de frontera del modelo matemático. Para la simulación del reactor de lecho fijo se empleó un modelo unidimensional pseudohomogeneo con parámetros aglomerados.

  14. Hunger in the absence of caloric restriction improves cognition and attenuates Alzheimer's disease pathology in a mouse model.

    Directory of Open Access Journals (Sweden)

    Emily J Dhurandhar

    Full Text Available It has been shown that caloric restriction (CR delays aging and possibly delays the development of Alzheimer's disease (AD. We conjecture that the mechanism may involve interoceptive cues, rather than reduced energy intake per se. We determined that hunger alone, induced by a ghrelin agonist, reduces AD pathology and improves cognition in the APP-SwDI mouse model of AD. Long-term treatment with a ghrelin agonist was sufficient to improve the performance in the water maze. The treatment also reduced levels of amyloid beta (Aβ and inflammation (microglial activation at 6 months of age compared to the control group, similar to the effect of CR. Thus, a hunger-inducing drug attenuates AD pathology, in the absence of CR, and the neuroendocrine aspects of hunger also prevent age-related cognitive decline.

  15. [Caloric nutritional evaluation of the menu served to the university community of the Universidad Nacional de San Luis, Republica Argentina].

    Science.gov (United States)

    Ascar José, M; Molíns de Pedernera, M; Moyano de Pringles, G; Guardia Calderón, C; Rodríguez de Farabelli, N; Luconi de Romero, M; Piola, H

    1993-06-01

    We have analysed the meals for lunch and dinner at the University cafeteria, during one Winter week (June through September); in this season the menus are repeated every week round. A percentage analysis (humidity, ashes, lipids, protein, raw fiber, and nitrogen-free extract) was carried out on the sample, which were appropriately processed, thus allowing us to know the nutrients amount and caloric value of each meal. When examining both the formulas ingredients and the technique applied to the preparation of the meals, it was found that they have the best cooking quality, and also that their amount is sufficient (see tables). As to the meals nutrients, the results allow us to conclude that the diets are hypercaloric as well as hypoproteic, with a preponderance of proteins of animal origin.

  16. PREFACE: XIII International Conference on Calorimetry in High Energy Physics (CALOR 2008)

    Science.gov (United States)

    Livan, Michele

    2009-07-01

    The XIII International Conference on Calorimetry in High Energy Physics was held in Pavia, Italy, 26-30 May 2008, picking up the baton from the 2006 Conference in Chicago. The Conference took place in the unique environment of the Theresian Room of the University Library. The attendees were surrounded by over 40 000 books of general interest and culture, and had the opportunity to see precious volumes written by such people as Galileo, Volta and Faraday. The Workshop brought together more than 120 participants, including senior scientists as well as young physicists, confirming the central and ever-growing role of calorimeters in modern particle physics. The development of these detectors, as stressed by Professor Klaus Pretzl in his lectio magistralis, has made it possible to explore new frontiers in physics, and the present scenario is no exception to this rule. With the LHC experiments almost completely installed and ready to take data, the Conference was an ideal chance to review the status of the different projects, whose development has been followed and discussed throughout the entire Calor series, and to show that they are capable of meeting the design specifications. Other highlights were the performance and physics results of calorimeters installed in currently operating experiments. In the session on astrophysics and neutrinos, the contributions confirmed the key role of calorimeters in this sector and demonstrated their growing application even beyond the field of accelerator physics. Considerable time was devoted to the state-of-the-art techniques in the design and operation of the detectors, while the session on simulation addressed the importance of a thorough understanding of the shower development to meet the demanding requirements of present experiments. Finally, on the R&D side, the particle flow and dual read-out concepts confronted the challenges issued by the next generation of experiments. This complex material was reviewed in 83

  17. Caloric restriction and intermittent fasting alter hepatic lipid droplet proteome and diacylglycerol species and prevent diabetes in NZO mice.

    Science.gov (United States)

    Baumeier, Christian; Kaiser, Daniel; Heeren, Jörg; Scheja, Ludger; John, Clara; Weise, Christoph; Eravci, Murat; Lagerpusch, Merit; Schulze, Gunnar; Joost, Hans-Georg; Schwenk, Robert Wolfgang; Schürmann, Annette

    2015-05-01

    Caloric restriction and intermittent fasting are known to improve glucose homeostasis and insulin resistance in several species including humans. The aim of this study was to unravel potential mechanisms by which these interventions improve insulin sensitivity and protect from type 2 diabetes. Diabetes-susceptible New Zealand Obese mice were either 10% calorie restricted (CR) or fasted every other day (IF), and compared to ad libitum (AL) fed control mice. AL mice showed a diabetes prevalence of 43%, whereas mice under CR and IF were completely protected against hyperglycemia. Proteomic analysis of hepatic lipid droplets revealed significantly higher levels of PSMD9 (co-activator Bridge-1), MIF (macrophage migration inhibitor factor), TCEB2 (transcription elongation factor B (SIII), polypeptide 2), ACY1 (aminoacylase 1) and FABP5 (fatty acid binding protein 5), and a marked reduction of GSTA3 (glutathione S-transferase alpha 3) in samples of CR and IF mice. In addition, accumulation of diacylglycerols (DAGs) was significantly reduced in livers of IF mice (P=0.045) while CR mice showed a similar tendency (P=0.062). In particular, 9 DAG species were significantly reduced in response to IF, of which DAG-40:4 and DAG-40:7 also showed significant effects after CR. This was associated with a decreased PKCε activation and might explain the improved insulin sensitivity. In conclusion, our data indicate that protection against diabetes upon caloric restriction and intermittent fasting associates with a modulation of lipid droplet protein composition and reduction of intracellular DAG species. Copyright © 2015. Published by Elsevier B.V.

  18. Estudio estructural en instalaciones de bomba de calor : Structural study of heat pump´s installations

    Directory of Open Access Journals (Sweden)

    Oscar M. Cruz Fonticiella

    2013-06-01

    Full Text Available Se investigan las irreversibilidades de una bomba de calor, con análisis exergéticos y estructurales. Se utilizó una instalación experimental de una bomba de calor lográndose datos y cálculos de la eficiencia de la compresión, temperaturas medias de los focos caliente y frío del ciclo, diferencia de temperatura a la salida del condensador, media logarítmica del evaporador, caídas de presiones del condensador y el evaporador y un análisis exergético y estructural con las propiedades termodinámicas en los puntos clave del ciclo, coeficiente de comportamiento del ciclo, balances de masas, energías y entropía, entropía generada en cada componente, balance de exergía con las irreversibilidades en cada componente, eficiencia exergética, defecto de eficiencia y coeficientes de vínculos estructurales Se exploraron las potencialidades de mejora de cada componente para una posterior optimización termoeconómica.The irreversibility of a heat pump with exergy and structural analysis is investigated. An experimental installation of a heat pump and calculations achieving data compression efficiency, the average temperature of hot and cold spots in the cycle was used, The temperature difference output condenser, log mean evaporator , pressures drops condenser and evaporator and structural exergy analysis and thermodynamic properties at key points of the cycle, the cycle coefficient of performance, mass balances, energy and entropy, entropy generated in each component, the availability balance irreversibilities in each component , exergetic efficiency, default coefficients efficiency and structural links were obtained. The potential for improvement for each component for further thermoeconomic optimization were explored

  19. Estudio estructural en instalaciones de bomba de calor; Structural study of heat pump´s installations

    Directory of Open Access Journals (Sweden)

    Oscar M. Cruz Fonticiella

    2013-06-01

    Full Text Available Se investigan las irreversibilidades de una bomba de calor, con análisis exergéticos y estructurales. Se utilizó una instalación experimental de una bomba de calor lográndose datos y cálculos de la eficiencia de la compresión, temperaturas medias de los focos caliente y frío del ciclo, diferencia de temperatura a la salida del condensador, media logarítmica del evaporador, caídas de presiones del condensador y el evaporador y un análisis exergético y estructural con las propiedades termodinámicas en los puntos clave del ciclo, coeficiente de comportamiento del ciclo, balances de masas, energías y entropía, entropía generada en cada componente, balance de exergía con las irreversibilidades en cada componente, eficiencia exergética, defecto de eficiencia y coeficientes de vínculos estructurales Se exploraron las potencialidades de mejora de cada componente para una posterior optimización termoeconómica.  The irreversibility of a heat pump with exergy and structural analysis is investigated. An experimental installation of a heat pump and calculations achieving data compression efficiency, the average temperature of hot and cold spots in the cycle was used, The temperature difference output condenser, log mean evaporator , pressures drops condenser and evaporator and structural exergy analysis and thermodynamic properties at key points of the cycle, the cycle coefficient of performance, mass balances, energy and entropy, entropy generated in each component, the availability balance irreversibilities in each component , exergetic efficiency, default coefficients efficiency and structural links were obtained. The potential for improvement for each component for further thermoeconomic optimization were explored.

  20. Predicting effective caloric value of nonnutritive factors: III. Feed form affects broiler performance by modifying behavior patterns.

    Science.gov (United States)

    Skinner-Noble, D O; McKinney, L J; Teeter, R G

    2005-03-01

    Two trials of an experiment were conducted to confirm the relationships among effective caloric value (ECV) of the diet, net energy for gain (NEg), BW, feed conversion ratio (FCR), and broiler behavior. Further, we sought to examine such factors with benefits of pelleting, including feed form history (pellets vs. mash) in females from 2 strains of commercial broilers. Composition of gain was measured on a sample of birds in both trials. In trial 1 birds were reared to 23 d on feed in crumble form, when the birds were provided a feed in pellet or mash form for 7 d. Pelleting the feed increased ECV and total NEg, while decreasing eating and increasing resting behavior. Significant correlations (P strain and feed form history combination were switched to the alternative feed form. Interactions of strain by grower feed form were present for BW, initial fat, and body energy content indicating that pelleted feed was required for optimum broiler performance of 1 strain. Grower feed form by finisher feed form interactions were present and demonstrated that birds switched from pellets or mash to the alternate feed form consumed more feed in less time than birds that remained on their previous feed form. Significant correlations were observed in both trials between behaviors and FCR and ECV, whereas NEg reflected these differences in trial 1 but not trial 2. Regression analysis indicated that FCR and subsequently ECV were best predicted by lean gain, whereas NEg was best predicted by fat gain. Further, regression analysis established interactive equations in which ECV was predicted (R2 > 0.99) by eating and resting behavior. The results of these trials indicate that the effects of feed form are caused by a modification of behavior patterns, that ECV is responsive to such behavior changes, and that ECV is an effective estimator of the relative caloric value of genetic, management, and husbandry influences.

  1. Estimativa do fluxo de calor latente pelo balanço de energia em cultivo protegido de pimentão

    Directory of Open Access Journals (Sweden)

    Cunha Antonio Ribeiro da

    2002-01-01

    Full Text Available O objetivo deste trabalho foi caracterizar e relacionar a radiação líquida com o calor latente equivalente, em mm de água, nos cultivos protegido e de campo, na cultura de pimentão. O experimento foi feito em Botucatu, SP. A estimativa do fluxo de calor latente foi feita pelo método do balanço de energia, por meio da razão de Bowen. Foram feitas medidas instantâneas da radiação líquida (Rn, dos fluxos convectivos de calor latente (LE e sensível (H, do fluxo de calor no solo (G, e dos gradientes psicrométricos sobre a cultura. O cultivo protegido, apesar de receber menor quantidade de radiação solar global, foi mais eficiente na conversão da radiação líquida disponível em matéria seca total e na produtividade de frutos. No balanço de energia, o cultivo protegido apresentou razões G/Rn e LE/Rn inferiores e H/Rn superior, com um fluxo de calor latente, equivalente em milímetros, 45,43% menor que no cultivo no campo. Apresentou, ainda, menor quantidade de radiação líquida disponível e menores perdas de energia, mostrando-se mais eficiente no uso da água.

  2. Determinación del requerimiento de frío y de calor en duraznero [Prunus persica (L. Batsch.] mediante un modelo de correlación

    Directory of Open Access Journals (Sweden)

    CHAAR, J

    2012-11-01

    Full Text Available Los árboles frutales de hoja no persistente poseen un período de reposo entre los ciclos vegetativos. Para salir de reposo invernal, las yemas deben acumular primero frío (endodormancia y luego calor (ecodormancia.El objetivo de este trabajo fue determinar el requerimiento de frío y de calor en cinco cultivares de duraznero mediante un método de correlación, con datos de fecha de plena floración y temperatura del aire de siete años, en el este de Mendoza. El requerimiento de frío varió entre 914 y 1262 unidades de frío, mientras que el de calor fluctuó entre 2177 y 6490 horas grado de crecimiento. Excepto en cv. “Prima”, la variabilidad entre años del requerimiento de frío (coeficiente de variación, CV: 18,3 a 18,9% fue mayor que la correspondiente al requerimiento de calor, (CV: 6,9 a 13,9%. Los requerimientos de calor disminuyeron en años de mayor acumulación de frío e indicaron una compensación. El modelo utilizado, permite disponer de información más precisa sobre los requerimientos térmicos de los cultivares, y así poder realizar una zonificación que racionaliceel cultivo y maximice su aprovechamiento, en las áreas agroclimáticamente adecuadas.

  3. Transferencia de calor incrementada en espacios anulares con elementos helicoidales insertados//Review of augmentation techniques for heat transfer coefficient in annular spaces using helical elements

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    Josué Imbert‐González

    2014-08-01

    Full Text Available La transferencia de calor incrementada por métodos pasivos se emplea en diversosintercambiadores de calor de alta efectividad. El objetivo del trabajo presentado fue la evaluación del estado de las investigaciones en el campo de la transferencia de calor mejorada en espacios anulares, a partir del empleo de elementos turbulizadores helicoidales como técnicas pasivas. La revisión se centró en el empleo de láminas helicoidales y espirales, la obtención de ecuaciones de correlación del coeficiente de transferencia de calor incrementado, el coeficiente de fricción y la evaluación que se realiza de este proceso por parte de diferentes autores. El análisis crítico permitió realizar valoraciones integradas y recomendar sobre los aspectos que podrían ser analizados en el futuro en esta temática.Palabras claves: transferencia de calor incrementada, láminas helicoidales, espirales, espacios anulares, métodos pasivos._______________________________________________________________________________AbstractThe transfer enhancement by passive methods is used in several heat exchanger of high effectiveness. The objective of the presented work was the evaluation of the state of the investigations in heat transfer enhancement in annular spaces, from the employment of elements helical. The revision was centered in the employment of twisted tape and wire coil in spiral, the equations of correlation obtained of the coefficient of transfer of increased heat, the coefficient of friction and the evaluation that was carried out of this process on the part of different authors. From the critical analysis of the published results, the authors recommend on the topics that can be analyzed in the future in this area.Key words: heat transfer enhancement, twisted tape, helical springs, annular spaces, passive methods.

  4. Fatores associados às ondas de calor em mulheres climatéricas: inquérito populacional domiciliar Factors associated with hot flashes in climacteric women: a population-based study

    Directory of Open Access Journals (Sweden)

    Danielle Santos-Sá

    2004-12-01

    Full Text Available OBJETIVO: identificar os fatores associados à ocorrência de ondas de calor em mulheres climatéricas residentes em Campinas, São Paulo. MÉTODOS: análise secundária de banco de dados de estudo descritivo de corte transversal, de base populacional. Foram selecionadas 456 mulheres por processo de amostragem, com idade entre 45-60 anos de idade. Os dados foram coletados por meio de entrevistas domiciliares, com questionários estruturados e pré-testados, fornecidos pela Fundação Internacional de Saúde/Sociedade Internacional de Menopausa e Sociedade Norte-Americana de Menopausa e adaptados pelos autores. As variáveis analisadas foram idade, cor, uso de métodos anticoncepcionais e terapia hormonal, laqueadura tubárea, índice de massa corpórea, estado menopausal, tempo de menopausa, histerectomia e tabagismo. Foram calculados a média, desvio padrão, mediana e razão de prevalência (RP. Realizou-se análise de regressão múltipla, utilizando o processo de seleção passo a passo, com intervalo de confiança de 95% (IC 95%. RESULTADOS: na análise bivariada, mulheres na pós-menopausa (RP: 1,42; IC 95%: 1,06-1,90 e histerectomizadas (RP: 1,50; IC 95%: 1,05-2,14 apresentaram chance significativamente maior de ocorrência de ondas de calor. A análise de regressão múltipla não mostrou associação significativa entre a presença de ondas de calor e as variáveis avaliadas. CONCLUSÃO: os resultados mostraram coerência com estudos anteriores, ou seja, ainda não é possível indicar os fatores que estão associados à ocorrência de ondas de calor.PURPOSE: to identify factors associated with the occurrence of hot flashes in climacteric women living in Campinas, São Paulo. METHODS: data bank secondary analysis of a cross-sectional descriptive population-based study. The selection of 456 women aged 45-60 years was done through area cluster sampling. Data were collected via home interviews using structured, pre-tested questionnaires

  5. Transferencia de Calor y Materia durante la Fritura de Trozos de Ñame (Dioscórea alata) Heat and Mass Transfer during the Frying of Slices of Yam (Dioscórea alata)

    OpenAIRE

    Armando Alvis; Luis E Cortés; Manuel Páez

    2009-01-01

    En el presente trabajo se analizó la transferencia de calor y materia durante el freído de trozos de ñame en aceite de soya a 140, 160, 180°C. Los coeficientes de transferencia de calor y materia fueron determinados a partir de las gráficas de las relaciones adimensionales de temperatura y concentración de humedad versus tiempo. Los coeficientes de transferencia de calor y materia se incrementaron al aumentar la temperatura del aceite. Para la variedad de ñame llamada Pico de Botella, la pérd...

  6. Estudio de la influencia del número de módulos termoeléctricos en la potencia calorífica disipada por un sistema de auto-refrigeración termoeléctrica

    OpenAIRE

    Conde Olazábal, Igor

    2014-01-01

    En el desarrollo del presente trabajo de fin de grado se expone un estudio sobre una de las múltiples aplicaciones de aprovechamiento de calor residual mediante termoelectricidad. Se trata de una aplicación novedosa y de creciente interés conocida por el nombre de “autorrefrigeración termoeléctrica” (ARTE). Dado un dispositivo cualquiera que genera calor, bien puedan ser transistores IGBT para el caso de electrónica de potencia o cualquier otra aplicación con generación de calor en el proceso...

  7. Exercise training improves relaxation response and SOD-1 expression in aortic and mesenteric rings from high caloric diet-fed rats

    Directory of Open Access Journals (Sweden)

    Antunes Edson

    2008-05-01

    Full Text Available Abstract Background Obesity has been associated with a variety of disease such as type II diabetes mellitus, arterial hypertension and atherosclerosis. Evidences have shown that exercise training promotes beneficial effects on these disorders, but the underlying mechanisms are not fully understood. The aim of this study was to investigate whether physical preconditioning prevents the deleterious effect of high caloric diet in vascular reactivity of rat aortic and mesenteric rings. Methods Male Wistar rats were divided into sedentary (SD; trained (TR; sedentary diet (SDD and trained diet (TRD groups. Run training (RT was performed in sessions of 60 min, 5 days/week for 12 weeks (70–80% VO2max. Triglycerides, glucose, insulin and nitrite/nitrate concentrations (NOx- were measured. Concentration-response curves to acetylcholine (ACh and sodium nitroprusside (SNP were obtained. Expression of Cu/Zn superoxide dismutase (SOD-1 was assessed by Western blotting. Results High caloric diet increased triglycerides concentration (SDD: 216 ± 25 mg/dl and exercise training restored to the baseline value (TRD: 89 ± 9 mg/dl. Physical preconditioning significantly reduced insulin levels in both groups (TR: 0.54 ± 0.1 and TRD: 1.24 ± 0.3 ng/ml as compared to sedentary animals (SD: 0.87 ± 0.1 and SDD: 2.57 ± 0.3 ng/ml. On the other hand, glucose concentration was slightly increased by high caloric diet, and RT did not modify this parameter (SD: 126 ± 6; TR: 140 ± 8; SDD: 156 ± 8 and TRD 153 ± 9 mg/dl. Neither high caloric diet nor RT modified NOx- levels (SD: 27 ± 4; TR: 28 ± 6; SDD: 27 ± 3 and TRD: 30 ± 2 μM. Functional assays showed that high caloric diet impaired the relaxing response to ACh in mesenteric (about 13%, but not in aortic rings. RT improved the relaxing responses to ACh either in aortic (28%, for TR and 16%, to TRD groups or mesenteric rings (10%, for TR and 17%, to TRD groups that was accompanied by up-regulation of SOD-1

  8. Melanin-Concentrating Hormone and Its MCH-1 Receptor: Relationship Between Effects on Alcohol and Caloric Intake.

    Science.gov (United States)

    Karlsson, Camilla; Aziz, Abdul Maruf Asif; Rehman, Faazal; Pitcairn, Caleb; Barchiesi, Riccardo; Barbier, Estelle; Wendel Hansen, Mikaela; Gehlert, Don; Steensland, Pia; Heilig, Markus; Thorsell, Annika

    2016-10-01

    Reward and energy homeostasis are both regulated by a network of hypothalamic neuropeptide systems. The melanin-concentrating hormone (MCH) and its MCH-1 receptor (MCH1-R) modulate alcohol intake, but it remains unknown to what extent this reflects actions on energy balance or reward. Here, we evaluated the MCH1-R in regulation of caloric intake and motivation to consume alcohol in states of escalated consumption. Rats had intermittent access (IA) to alcohol and were divided into high- and low-drinking groups. Food and alcohol consumption was assessed after administration of an MCH1-R antagonist, GW803430. Next, GW803430 was evaluated on alcohol self-administration in protracted abstinence induced by IA in high-drinking rats. Finally, the effect of GW803430 was assessed on alcohol self-administration in acute withdrawal in rats exposed to alcohol vapor. Gene expression of MCH and MCH1-R was measured in the hypothalamus and nucleus accumbens (NAc) in both acute and protracted abstinence. High-drinking IA rats consumed more calories from alcohol than chow and GW803430 decreased both chow and alcohol intake. In low-drinking rats, only food intake was affected. In protracted abstinence from IA, alcohol self-administration was significantly reduced by pretreatment with GW803430 and gene expression of both MCH and the MCH1-R were dysregulated in hypothalamus and NAc. In contrast, during acute withdrawal from vapor exposure, treatment with GW803430 did not affect alcohol self-administration, and no changes in MCH or MCH1-R gene expression were observed. Our data suggest a dual role of MCH and the MCH1-R in regulation of alcohol intake, possibly through mechanisms involving caloric intake and reward motivation. A selective suppression of alcohol self-administration during protracted abstinence by GW803430 was observed and accompanied by adaptations in gene expression of MCH and MCH1-R. Selective suppression of escalated consumption renders the MCH1-R an attractive target

  9. Fasting during Ramadan and Associated Changes in Glycaemia, Caloric Intake and Body Composition with Gender Differences in Singapore.

    Science.gov (United States)

    Yeoh, Ester C K; Zainudin, Sueziani Binte; Loh, Win Nie; Chua, Chin Lian; Fun, Sharon; Subramaniam, Tavintharan; Sum, Chee Fang; Lim, Su Chi

    2015-06-01

    Millions of Muslim patients with diabetes mellitus (DM) fast during Ramadan. However, little is known about the metabolic impact of Ramadan fasting. We aimed to study the changes in body composition and metabolic profile in this group of patients. We studied 29 Southeast Asian Muslim patients with type 2 diabetes; all underwent pre-Ramadan education. Study variables were weight change, body composition (using multifrequency bioimpedance method, InBody S20®, Biospace, South Korea), blood pressure (BP), glycated haemoglobin (HbA1c), fasting lipid profile, and caloric intake assessment using FoodWorks® nutrient analysis software. Twenty-three subjects fasted ≥15 days; mean ± SD: 57 ± 11 years; 52% were males. HbA1c improved significantly (8.6 ± 2.4% pre-Ramadan vs 8.0 ± 2.3% end-Ramadan, P = 0.017). Despite similar body weight, there was reduction in body fat mass (BFM) (30.9 ± 11 kg vs 29.2 ± 12.2 kg, P = 0.013). Multivariate analysis suggested that the reduction in HbA1c was attributed by reduction in BFM (β = -0.196, P = 0.034). There was no change in visceral adiposity (visceral fat area (VFA)) but stratification by gender showed a reduction amongst females (137.6 ± 24.5 cm2 to 132.5 ± 25.7 cm2, P = 0.017). These changes occurred despite similar total caloric intake (1473.9 ± 565.4 kcal vs 1473.1 ± 460.4 kcal, P = 0.995), and proportion of carbohydrate (55.4 ± 6.3% vs 53.3 ± 7.5%, P = 0.25) and protein intake (17.6 ± 4.1% vs 17.3 ± 5.4%, P = 0.792), before and during Ramadan respectively, but with increased proportion of fat intake (11.9 ± 2.4% vs 13 ± 11.7%, P = 0.04). Seven out of 23 patients had medications adjusted to avert symptomatic hypoglycaemia but none of the patients developed severe hypoglycaemia. Ramadan fasting can be practiced safely with prior patient education and medication adjustment. It also confers modest benefits on metabolic profile and body composition, especially among females.

  10. Flexoelectric Induced Caloric Effect in Truncated Pyramid Shaped Ba0.67Sr0.33TiO3 Ferroelectric Material

    Science.gov (United States)

    Patel, Satyanarayan; Chauhan, Aditya; Madhar, Niyaz Ahamad; Ilahi, Bouraoui; Vaish, Rahul

    2017-07-01

    Solid state refrigeration based on ferroelectric materials can potentially be competing in not-in-kind refrigeration technology. However, their functionality is currently limited to Curie temperatures. Through this article, authors have attempted to describe an unexplored component of the stress-driven caloric effect, obtainable beyond the Curie point. The phenomenon, termed as the flexocaloric effect (FCE), relies on inhomogeneous straining of the crystal lattice to induce polarization in centrosymmetric crystals (flexoelectricity). For this study, a truncated pyramid geometry was selected, and the dependence of sample height on caloric capacity was studied. A peak temperature change of 1.75 K (313 K) was estimated for Ba0.67Sr0.33TiO3 (BST) ceramics employing a truncated pyramid configuration.

  11. Horas frío y horas de calor en zonas climáticas de la España peninsular (2002-2011)

    OpenAIRE

    García Merayo, José Luis; Gallego Abaroa, Teresa; Martínez Núñez, Lourdes

    2015-01-01

    Esta publicación pretende dar una idea aproximada del número de horas frío y horas de calor que se dan en las distintas zonas climáticas peninsulares, así como la aproximación que, a esos valores, proporciona la fórmula de Crossa-Raynaud, la más utilizada para su cálculo. No se trata de proponer, justificar o refutar determinadas hipótesis o métodos para el cálculo de horas frío o de calor, sino simplemente de aceptar la utilidad en las aplicaciones climáticas de estas variables derivadas y h...

  12. Análisis de la incertidumbre del poder calorífico en un motor de combustión interna alternativo

    OpenAIRE

    YILMAZ SOÑORA, NARIN

    2017-01-01

    [ES] Dentro del marco del diagnóstico de la combustión, es interesante el análisis de la incertidumbre del poder calorífico en un motor de combustión interna alternativo. Con ello, se pretende conocer con mayor certeza la energía aprovechable de la cual se dispone en un proceso de combustión. El objetivo de este trabajo es observar la influencia del fenómeno de la disociación sobre el poder calorífico en un motor de combustión interna alternativo. Para ello, a través de las herram...

  13. Construcción de un calorímetro isoperibolico de inmersión de precisión

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo G.

    2010-07-01

    Full Text Available Se diseña y construye un calorímetro isoperibólico tipo submarino para la medida de calores de inmersión de sólidos en líquidos. La celda calorimétrica, de una capacidad aproximada de 85 mi, se fabrica en vidrio Pyrex y va sumergida dentro de una chaqueta submarina construida en bronce cromado. El conjunto se introduce dentro de un termostato de agua estabilizado a 25 ±0,001 °C. El sensor de temperatura está constituido por termisiores NTC colocados en un puente de Maier transpuesto y provisto de una Fuente de intensidad constante. La sensibilidad del termómetro es del orden de 5 * I O' °C/p V cuando la corriente de medida en el puente es del orden de 1 mA.

  14. Determinación del calor isostérico para pulpa de plátano (musa paradisiaca) por isotermas de sorción

    OpenAIRE

    CIRO, HÉCTOR; OSORIO, JAIRO ALEXANDER; CORTÉS, ELKIN ALONSO

    2008-01-01

    Las isotermas de sorción para ser usadas en la simulación y diseño de procesos de secado y almacenamiento de alimentos deben ser representadas por modelos válidos dentro de las condiciones encontradas en la práctica industrial. Usando el modelo de Chung–Pfost y ajustado por desorción el calor isostérico neto y total para pulpa de plátano fueron determinados. El calor neto isotérico neto decreció con el contenido de humedad del producto variando desde 1670 kJ/kg (5%.d.b) a 215 kJ/kg (26%.d.b...

  15. Comparative analysis of the post caloric nystagmus with two and four stimulations by means of the vectoeletronistagmography - doi:10.5020/18061230.2004.p135

    Directory of Open Access Journals (Sweden)

    Renata Parente de Almeida

    2012-01-01

    Full Text Available Vertigo is one of the most common symptoms nowadays and its diagnosis is based on the patient’s clinical history and on the otoneurological exam. This study aimed at analyzing the vestibular dysfunction diagnosis efficacy by using only cold caloric irrigation in vectoeletronistagmography. A retrospective survey of 174 vectoeletronistagmography exams from patients of the Audiology sector of Nucleo de Atenção Médica Integrada (NAMI in the University of Fortaleza was done, by comparing the results with two and four irrigations. From the analysed exams, 64 (36,78 % were symmetrical only with the single caloric irrigation (cold water and 110 (63,22 % were not. This kind of procedure is not efficient for the diagnosis, but it can be useful for screening, although a new study is necessary for validation

  16. Comparison between Human and Bite-Based Methods of Estimating Caloric Intake.

    Science.gov (United States)

    Salley, James N; Hoover, Adam W; Wilson, Michael L; Muth, Eric R

    2016-10-01

    Current methods of self-monitoring kilocalorie intake outside of laboratory/clinical settings suffer from a systematic underreporting bias. Recent efforts to make kilocalorie information available have improved these methods somewhat, but it may be possible to derive an objective and more accurate measure of kilocalorie intake from bite count. This study sought to develop and examine the accuracy of an individualized bite-based measure of kilocalorie intake and to compare that measure to participant estimates of kilocalorie intake. It was hypothesized that kilocalorie information would improve human estimates of kilocalorie intake over those with no information, but a bite-based estimate of kilocalorie intake would still outperform human estimates. Two-hundred eighty participants were allowed to eat ad libitum in a cafeteria setting. Their bite count and kilocalorie intake were measured. After completion of the meal, participants estimated how many kilocalories they consumed, some with the aid of a menu containing kilocalorie information and some without. Using a train and test method for predictive model development, participants were randomly divided into one of two groups: one for model development (training group) and one for model validation (test group). Multiple regression was used to determine whether height, weight, age, sex, and waist-to-hip ratio could predict an individual's mean kilocalories per bite for the training sample. The model was then validated with the test group, and the model-predicted kilocalorie intake was compared with human-estimated kilocalorie intake. Only age and sex significantly predicted mean kilocalories per bite, but all variables were retained for the test group. The bite-based measure of kilocalorie intake outperformed human estimates with and without kilocalorie information. Bite count might serve as an easily measured, objective proxy for kilocalorie intake. A tool that can monitor bite count may be a powerful assistant to

  17. Energy saving in hotels by means of heat pumps application; Ahorro de energia en hoteles mediante la aplicacion de bombas de calor

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes R, Hernando; Ambriz G, Juan Jose [Universidad Autonoma Metropolitana, Unidad Iztapalapa (Mexico)

    2005-07-15

    The thermal energy is presented as an alternate saving technology for utilities by means of the acute implementation of heat pumps. The objective is to demonstrate the technical and economical feasibility of the application of commercial heat pumps to installations where the handling of opposite temperatures for the conditioning of a space and/or of a fluid is required. In this article it is described the functioning of a heat pump, its different operation principles or types as well as the large diversity of applications they can have in industry, utilities and residential buildings. As an application example the substitution of an electric boiler by a heat pump is presented in a hotel installation and its differences in performance regarding the environmental conditioning of a nearby area and the heating of swimming pool water are analyzed. [Spanish] Se presenta la energia termica como una tecnologia de ahorro alterna para empresas de servicios valiendose de la implementacion agudizada de bombas de calor. El objetivo es demostrar la factibilidad tecnica y economica de la aplicacion de bombas de calor comerciales a instalaciones donde se requiere la manipulacion de temperaturas opuestas para el acondicionamiento de un espacio y/o un fluido. Se describe el funcionamiento de una bomba de calor, sus diferentes principios de operacion o tipos, asi como la gran diversidad de aplicaciones que pueden tener en la industria, empresas de servicios y edificios residenciales. Como ejemplo de aplicacion se presenta la sustitucion de una caldera electrica por una bomba de calor en una instalacion hotelera y sus diferencias de rendimiento en el calentamiento de agua de alberca y el acondicionamiento ambiental de un area cercana.

  18. Evaluación de un recuperador de calor en una industria frigorífica//Evaluation of waste heat recovery in frigorific industry

    Directory of Open Access Journals (Sweden)

    Josué Imbert‐González

    2014-01-01

    Full Text Available La recuperación de calor forma parte de las medidas propuestas para el empleo adecuado del amoniaco en países tropicales. Este artículo analiza un sistema de recuperación de calor instalado en una instalación de refrigeración industrial. En el análisis, que parte de las lecturas comparativas de parámetros de operación de la instalación, se determinó la efectividad del intercambio térmico, el incremento en laeficiencia del sistema de refrigeración, así como el combustible ahorrado por concepto de calentamiento del agua en la industria. Los resultados obtenidos reportaron que el diseño térmico basado en intercambio de calor en espacios anulares, permite un ahorro importante de recursos y un elevado índice de aprovechamiento térmico.Palabras claves: recuperación de calor, instalación frigorífica, ahorro de energía.________________________________________________________________________________AbstractThe waste heat recovery by heat pipes is accepted as an excellent way of saving energy and preventing global warming. This article assesses the impact of the use of a heat exchanger used as a heat recovery in the refrigeration industry. Elements are evaluated from the point of view of heat transfer, evaluating the quality of heat exchange process. Is calculated increase in the efficiency of the cooling system. The heated water is used in the steam generation system of the industry. Is calculated fuel consumption savings resulting from this warming. The findings provide elements that show the enormous potential of this technique in the refrigeration industry.Key words: waste heat recovery, Industrial refrigeration, saving energy.

  19. Heat transfer study for convection and radiation in an open cavity; Estudio de de la transferencia de calor por convencion y radiacion en una cavidad abierta

    Energy Technology Data Exchange (ETDEWEB)

    Cabanillas Lopez, Rafael E [Universidad de Sonora, Hermosillo, Sonora (Mexico); Estrada Gasca, Claudio A [Centro de Investigacion en Energia-UNAM, Temixco, Morelos (Mexico); Alvarez Garcia, Gabriela S [CENIDET, Cuernavaca, Morelos (Mexico)

    2000-07-01

    Interaction of natural convection and radiation heat transfer in an open side square cavity has been simulated numerically. Previous studies have shown results of the simulation of heat transfer for convection on this geometry. This paper reports the effect of considering both the convection and the radiation mechanisms. Radiation was found to have a great influence on the total amount of heat lost by the cavity as well as on the pattern of flow and on the temperature field. Computations were performed within the domain of the cavity for two-dimensional laminar flow problem. The average of heat transfer coefficient was calculated for several values of the Grashof number for air (Pr = 0.7), with the bottom wall at 500 K (constant temperature) and the open side at 300 K. [Spanish] Se presenta el estudio de la interaccion conveccion natural-radiacion en una cavidad rectangular abierta. Algunos estudios anteriores han mostrado resultados sobre la transferencia de calor por el mecanismo de conveccion natural sobre cavidades abiertas. Aqui se presenta la influencia de considerar ambos mecanismos de transferencia de calor, la conveccion y la radiacion. Se demuestra que el intercambio radiactivo tiene una gran influencia tanto en la cantidad total de calor perdido por la cavidad al ambiente, como en el patron de flujo y de temperatura dentro de la cavidad. Se resuelven numericamente las ecuaciones gobernantes para flujo laminar en dos dimensiones y se calcula el coeficiente promedio de transferencia de calor para diferentes valores del Grashof en una cavidad llena de aire (Pr 0.7), teniendo la pared del fondo de la cavidad a 500 K y los alrededores a 300 K.

  20. Caloric restriction favorably impacts metabolic and immune/inflammatory profiles in obese mice but curcumin/piperine consumption adds no further benefit

    OpenAIRE

    Wang, Junpeng; Vanegas, Sally M; Du, Xiaogang; Noble, Timothy; Zingg, Jean-Marc A; Meydani, Mohsen; Meydani, Simin Nikbin; Wu, Dayong

    2013-01-01

    Background Obesity is associated with low-grade inflammation and impaired immune response. Caloric restriction (CR) has been shown to inhibit inflammatory response and enhance cell-mediated immune function. Curcumin, the bioactive phenolic component of turmeric spice, is proposed to have anti-obesity and anti-inflammation properties while piperine, another bioactive phenolic compound present in pepper spice, can enhance the bioavailability and efficacy of curcumin. This study sought to determ...

  1. Mixing of acacia bark and palm shells to increase caloric value of palm shells white charcoal briquette

    Science.gov (United States)

    Kurniawan, Edy Wibowo; Amirta, Rudianto; Budiarso, Edy; Arung, Enos Tangke

    2017-06-01

    Indonesia is greatly rich in biomass resources. Acacia bark waste utilization as a source of biomass is still very low, where as 10-20% of the potential of the wood. On the other hand waste palm shells have been partly utilized as boiler fuel oil plant as much as 62.4%, but the rest is still a waste pile or to the hardening of the estate path. This study aims to determine the effect of mixing an acacia bark with palm shells to increase the calorific value of palm shell white charcoal briquettes. The study was conducted by making white charcoal briquettes mixing 7% the acacia bark against of palm shells. As well as white charcoal briquettes control without any acacia bark. Then molds the briquettes in pyrolysis temperature at 600 ° C, 700 ° C and 800 ° C for pyrolysis time within 2 hours, 4 hours, and 6 hours. And the results of briquettes analysis in calorific value. The results showed that the caloric value of palm shell white charcoal briquettes increased from 29691.14 Kcal / kg to 31941.50 Kcal / kg.

  2. Electrocaloric effect in BaTiO3 at all three ferroelectric transitions: Anisotropy and inverse caloric effects

    Science.gov (United States)

    Marathe, Madhura; Renggli, Damian; Sanlialp, Mehmet; Karabasov, Maksim O.; Shvartsman, Vladimir V.; Lupascu, Doru C.; Grünebohm, Anna; Ederer, Claude

    2017-07-01

    We study the electrocaloric (EC) effect in bulk BaTiO3 (BTO) using molecular dynamics simulations of a first principles-based effective Hamiltonian, combined with direct measurements of the adiabatic EC temperature change in BTO single crystals. We examine in particular the dependence of the EC effect on the direction of the applied electric field at all three ferroelectric transitions, and we show that the EC response is strongly anisotropic. Most strikingly, an inverse caloric effect, i.e., a temperature increase under field removal, can be observed at both ferroelectric-ferroelectric transitions for certain orientations of the applied field. Using the generalized Clausius-Clapeyron equation, we show that the inverse effect occurs exactly for those cases where the field orientation favors the higher temperature/higher entropy phase. Our simulations show that temperature changes of around 1 K can, in principle, be obtained at the tetragonal-orthorhombic transition close to room temperature, even for small applied fields, provided that the applied field is strong enough to drive the system across the first-order transition line. Our direct EC measurements for BTO single crystals at the cubic-tetragonal and at the tetragonal-orthorhombic transitions are in good qualitative agreement with our theoretical predictions, and in particular confirm the occurrence of an inverse EC effect at the tetragonal-orthorhombic transition for electric fields applied along the [001] pseudocubic direction.

  3. Stress and hunger alter the anorectic efficacy of fluoxetine in binge-eating rats with a history of caloric restriction.

    Science.gov (United States)

    Placidi, Rachel J; Chandler, Paula C; Oswald, Kimberly D; Maldonado, Christine; Wauford, Pamela K; Boggiano, Mary M

    2004-11-01

    We examined the effect of fluoxetine to suppress binge eating in rats with a history of caloric restriction (CR) and the extent to which this effect was altered by stress and hunger. To detect heightened sensitivity to fluoxetine, young female rats were used to determine a subthreshold anorectic dose (2 mg/kg, intraperitonally). Another group of rats was either fed ad libitum or given multiple CR (to 90% body weight) and refeeding-to-satiety cycles. One half of the rats were then either spared or subjected to foot shock stress before fluoxetine treatment. A history of CR alone produced bingelike eating on palatable food (p stress did not affect intake, it rendered CR rats hypersensitive to the satiety effect of fluoxetine. The feeding-suppression was mainly for chow (p < .05) and the effect was abolished if the rats were in negative energy balance. Results support the utility of this animal model to elucidate serotonergic changes linking dieting to binge eating. The diverse effects of fluoxetine on the type of food, and in hungry versus sated rats, suggest alternate brain mechanisms should be concomitantly targeted for improved treatment of binge eating disorders.

  4. Wide Variability in Caloric Density of Expressed Human Milk Can Lead to Major Underestimation or Overestimation of Nutrient Content.

    Science.gov (United States)

    Sauer, Charles W; Boutin, Mallory A; Kim, Jae H

    2017-05-01

    Very-low-birth-weight infants continue to face significant difficulties with postnatal growth. Human milk is the optimal form of nutrition for infants but may exhibit variation in nutrient content. This study aimed to perform macronutrient analysis on expressed human milk from mothers whose babies are hospitalized in the neonatal intensive care unit. Up to five human milk samples per participant were analyzed for protein, carbohydrate, and fat content using reference chemical analyses (Kjeldahl for protein, high pressure liquid chromatography for carbohydrates, and Mojonnier for fat). Calorie content was calculated. A total of 64 samples from 24 participants was analyzed. Wide variability was found in calorie, protein, carbohydrate, and fat composition. The authors found an average of 17.9 kcal/ounce, with only 34% of samples falling within 10% of the expected caloric density. The assumption that human milk contains 20 kcal/ounce is no longer supported based on this study. This supports promoting an individualized nutrition strategy as a crucial aspect to optimal nutrition.

  5. Caloric restriction and intermittent fasting alter spectral measures of heart rate and blood pressure variability in rats.

    Science.gov (United States)

    Mager, Donald E; Wan, Ruiqian; Brown, Martin; Cheng, Aiwu; Wareski, Przemyslaw; Abernethy, Darrell R; Mattson, Mark P

    2006-04-01

    Dietary restriction (DR) has been shown to increase life span, delay or prevent age-associated diseases, and improve functional and metabolic cardiovascular risk factors in rodents and other species. To investigate the effects of DR on beat-to-beat heart rate and diastolic blood pressure variability (HRV and DPV) in male Sprague-Dawley rats, we implanted telemetric transmitters and animals were maintained on either intermittent fasting (every other day feeding) or calorie-restricted (40% caloric reduction) diets. Using power spectral analysis, we evaluated the temporal profiles of the low- and high-frequency oscillatory components in heart rate and diastolic blood pressure signals to assess cardiac autonomic activity. Body weight, heart rate, and systolic and diastolic blood pressure were all found to decrease in response to DR. Both methods of DR produced decreases in the low-frequency component of DPV spectra, a marker for sympathetic tone, and the high-frequency component of HRV spectra, a marker for parasympathetic activity, was increased. These parameters required at least 1 month to become maximal, but returned toward baseline values rapidly once rats resumed ad libitum diets. These results suggest an additional cardiovascular benefit of DR that merits further studies of this potential effect in humans.

  6. “Entropics”: Science and engineering of caloric phenomena related to itinerant-electron magnetism and spin fluctuations

    Science.gov (United States)

    Fujita, Asaya; Takenaka, Koshi

    2017-06-01

    In this paper, the relationship between giant caloric phenomena and itinerant-electron magnetism is examined in order to construct of a newly proposed concept “Entropics”, which is a fusion of science and technology with the objective of solving and controlling entropic phenomena. An anomalous hall resistivity is present in the paramagnetic state of the La(Fe0.88Si0.12)13 magnetocaloric compound. Further, its coefficient exhibits a Curie-Weiss type temperature dependence, indicating the existence of disordered local moment, even though the Rhodes-Wohlfarth (RW) ratio reveals that the magnetic feature in the system is an itinerant-electron type. In addition, the correlation between the magnitude of the transition entropy change of the itinerant-electron metamagnetic transition and the RW ratio was observed. In the Mn3GaN barocaloric compound, the transition entropy of the first-order antiferromagnetic-paramagnetic phase transition marginally depends on the external pressure, in contrast to the data for Gd5Ge2Si2. The origin of this tendency is phase stability against the pressure, as opposed to large volume change at the transition temperature, which results in an enhancement of the barocaloric effect. The influence of topological frustration is also distinguished by comparing it with that of other Mn-based antiperovskite compounds.

  7. Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo

    Science.gov (United States)

    Novelle, Marta G.; Davis, Ashley; Price, Nathan L.; Ali, Ahmed; Fürer-Galvan, Stefanie; Zhang, Yongqing; Becker, Kevin; Bernier, Michel; de Cabo, Rafael

    2015-01-01

    Caloric restriction (CR) without malnutrition is one of the most consistent strategies for increasing mean and maximal lifespan and delaying the onset of age-associated diseases. Stress resistance is a common trait of many long-lived mutants and life-extending interventions, including CR. Indeed, better protection against heat shock and other genotoxic insults have helped explain the pro-survival properties of CR. In this study, both in vitro and in vivo responses to heat shock were investigated using two different models of CR. Murine B16F10 melanoma cells treated with serum from CR-fed rats showed lower proliferation, increased tolerance to heat shock and enhanced HSP-70 expression, compared to serum from ad libitum-fed animals. Similar effects were observed in B16F10 cells implanted subcutaneously in male C57BL/6 mice subjected to CR. Microarray analysis identified a number of genes and pathways whose expression profile were similar in both models. These results suggest that the use of an in vitro model could be a good alternative to study the mechanisms by which CR exerts its anti-tumorigenic effects. PMID:25948793

  8. Caloric Restriction and the Nutrient-Sensing PGC-1α in Mitochondrial Homeostasis: New Perspectives in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Daniele Lettieri Barbato

    2012-01-01

    Full Text Available Mitochondrial activity progressively declines during ageing and in many neurodegenerative diseases. Caloric restriction (CR has been suggested as a dietary intervention that is able to postpone the detrimental aspects of aging as it ameliorates mitochondrial performance. This effect is partially due to increased mitochondrial biogenesis. The nutrient-sensing PGC-1α is a transcriptional coactivator that promotes the expression of mitochondrial genes and is induced by CR. It is believed that many of the mitochondrial and metabolic benefits of CR are due to increased PGC-1α activity. The increase of PGC-1α is also positively linked to neuroprotection and its decrement has been involved in the pathogenesis of many neurodegenerative diseases. This paper aims to summarize the current knowledge about the role of PGC-1α in neuronal homeostasis and the beneficial effects of CR on mitochondrial biogenesis and function. We also discuss how PGC-1α-governed pathways could be used as target for nutritional intervention to prevent neurodegeneration.

  9. Reversibility of β-Cell-Specific Transcript Factors Expression by Long-Term Caloric Restriction in db/db Mouse

    Directory of Open Access Journals (Sweden)

    Chunjun Sheng

    2016-01-01

    Full Text Available Type 2 diabetes (T2D is characterized by β-cell dedifferentiation, but underlying mechanisms remain unclear. The purpose of the current study was to explore the mechanisms of β-cell dedifferentiation with and without long-term control of calorie intake. We used a diabetes mouse model (db/db to analyze the changes in the expression levels of β-cell-specific transcription factors (TFs and functional factors with long-term caloric restriction (CR. Our results showed that chronic euglycemia was maintained in the db/db mice with long-term CR intervention, and β-cell dedifferentiation was significantly reduced. The expression of Glut2, Pdx1, and Nkx6.1 was reversed, while MafA expression was significantly increased with long-term CR. GLP-1 pathway was reactivated with long-term CR. Our work showed that the course of β-cell dedifferentiation can intervene by long-term control of calorie intake. Key β-cell-specific TFs and functional factors play important roles in maintaining β-cell differentiation. Targeting these factors could optimize T2D therapies.

  10. Caloric restriction increases internal iliac artery and penil nitric oxide synthase expression in rat: Comparison of aged and adult rats

    Directory of Open Access Journals (Sweden)

    Emin Ozbek

    2013-09-01

    Full Text Available Because of the positive corelation between healthy cardiovascular system and sexual life we aimed to evaluate the effect of caloric restriction (CR on endothelial and neuronal nitric oxide synthase (eNOS, nNOS expression in cavernousal tissues and eNOS expression in the internal iliac artery in young and aged rats. Young (3 mo, n = 7 and aged (24 mo, n = 7 male Sprague-Dawley rats were subjected to 40% CR and were allowed free access to water for 3 months. Control rats (n = 14 fed ad libitum had free access to food and water at all times. On day 90, rats were sacrified and internal iliac arteries and penis were removed and parafinized, eNOS and nNOS expression evaluated with immunohistochemistry. Results were evaluated semiquantitatively. eNOS and nNOS expression in cavernousal tis- sue in CR rats were more strong than in control group in both young and old rats. eNOS expression was also higher in the internal iliac arteries of CR rats than in control in young and old rats. As a result of our study we can say that there is a positive link between CR and neurotransmitter of erection in cavernousal tissues and internal iliac arteries. CR has beneficial effect to prevent sexual dysfunction in young and old animals and possible humans.

  11. NT-Pro-B-Type Natriuretic Peptide Levels in Infants with Failure to Thrive due to Caloric Deprivation

    Directory of Open Access Journals (Sweden)

    L. B. Mänhardt

    2010-01-01

    Methods. In a retrospective cohort study, we compared N-BNP levels from all consecutive infants with FTT and bodyweight below the tenth percentile (caloric deprivation (CD group to infants with severe HF. Reference values from infants between 2 and 12 month were taken from the literature and healthy infants. Results. Our results show that infants with FTT (n=15 had significantly (P<.001 elevated N-BNP values compared with the healthy infants (n=23, 530 (119–3150 pg/mL versus 115 (15–1121 pg/mL. N-BNP values in this CD group are comparable to the median value of infants with severe HF (n=12 673 (408–11310 pg/mL. There is no statistical significant difference in age. Conclusion. Nutritional state has an important impact on N-BNP levels in infants with FTT. We could show comparable levels of N-BNP in infants with FTT and infants with severe HF.

  12. comment="please make the changes marked up in the attached pdf"Sex-Dependent Effects of Caloric Restriction on the Ageing of an Ambush Feeding Copepod.

    Science.gov (United States)

    Saiz, Enric; Calbet, Albert; Griffell, Kaiene

    2017-10-04

    Planktonic copepods are a very successful group in marine pelagic environments, with a key role in biogeochemical cycles. Among them, the genus Oithona is one of the more abundant and ubiquitous. We report here on the effects of caloric (food) restriction on the ageing patterns of the copepod Oithona davisae. The response of O. davisae to caloric restriction was sex dependent: under food limitation, females have lower age-specific mortality rates and longer lifespans and reproductive periods; male mortality rates and life expectancy were not affected. Males are more active swimmers than females, and given their higher energetic demands presumably generate reactive oxygen species at higher rates. That was confirmed by starvation experiments, which showed that O. davisae males burn through body reserves much faster, resulting in shorter life expectancy. Compared with common, coastal calanoid copepods, the effects of caloric restriction on O. davisae appeared less prominent. We think this difference in the magnitude of the responses is a consequence of the distinct life-history traits associated with the genus Oithona (ambush feeder, egg-carrier), with much lower overall levels of metabolism and reproductive effort.

  13. Hybrid system: Heat pump-solar air dryer for grains; Sistema hibrido: bomba de calor - calentador solar de aire para el secado de productos agricolas

    Energy Technology Data Exchange (ETDEWEB)

    Soto Gomez, Willfredo [Instituto Tecnologico de Tijuana, Tijuana (Mexico); Ortega Herrera, Jose Angel [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

    2000-07-01

    Design, building, operation and evaluation energy wise of a hybrid experimental type, with heat pump, that uses no chloride, does not destroy the ozone layer. It is solar air dryer for grains. In this research we dry rice. It has tree systems: 1.- A mechanical compression heat pump, 2.- An air solar heater, and 3.- An agriculture products dryer. The drying capacity is 20 pounds of grain /day, with a median daily solar radiation. The costs is approximately U.S. $ 6 000.00. The heat pump used 22 refrigerant first, and now works with refrigerant SUVA 9000. This refrigerant will be available this year in the I.S., it is one of the ecological class that substitutes the chlorofluorocarbonates. [Spanish] Se disena, construye, opera, y evalua energeticamente, un sistema hibrido tipo experimental, con bomba de calor que utiliza refrigerante que no contiene cloro, y no destruye la capa de ozono y un calentador solar de aire, para secar granos. En este trabajo secamos arroz. Se compone de tres sistemas: 1.- Bomba de calor por compresion mecanica, 2.- Calentador solar de aire, 3.- Secador de productos agricolas. La capacidad de secado es de 10 Kilos de granos/dia promedio. Tiene un costo aproximado de $ 60 000. La bomba de calor utiliza refrigerante 22 en una primera generacion, y actualmente opera con un refrigerante SUVA 9000, en una segunda generacion, este refrigerante se comercializara en este ano, en la Union Americana, pertenece a la familia de los llamados refrigerantes ecologicos, sustitutos de los clorofluorocarbonados.

  14. Índice de reflectancia solar de revestimientos verticales: potencial para la mitigación de la isla de calor urbana

    Directory of Open Access Journals (Sweden)

    Noelia Liliana Alchapar

    Full Text Available La condición artificial del medio urbano modifica el consumo de energía y el confort térmico. El incremento de las temperaturas de una ciudad en relación a las áreas periféricas conduce a la formación de una Isla de Calor Urbana. Es por ello, que trabajar sobre las propiedades termofísicas de los materiales (techos, pavimentos y fachadas es una estrategia de mitigación viable para disminuir las temperaturas de una ciudad. El objetivo principal de éste trabajo es estudiar la capacidad de 80 revestimientos para fachadas disponibles regionalmente para mitigar los efectos negativos de la Isla deCalor Urbana, mediante la determinación del Índice de Reflectancia Solar (SRI. El material que posee el comportamiento más eficiente es el Acrílico Rulato Travertino fino marfil (SRI = 100%, Temp. Sup.= 35 ºC, mientras el más ineficiente es el Acrílico Llaneado fino gris plomo (SRI = 29%, Temp. Sup.= 74 ºC. No obstante existen alternativas intermedias que resultan del efecto combinado de la composición del material, su color y textura. Esta situación demuestra que es posible mitigar el efecto de isla de calor a partir de una adecuada selección de revestimientos verticales.

  15. Caloric restriction induces energy-sparing alterations in skeletal muscle contraction, fiber composition and local thyroid hormone metabolism that persist during catch-up fat upon refeeding

    Directory of Open Access Journals (Sweden)

    Paula Bresciani M. De Andrade

    2015-09-01

    Full Text Available Weight regain after caloric restriction results in accelerated fat storage in adipose tissue. This catch-up fat phenomenon is postulated to result partly from suppressed skeletal muscle thermogenesis, but the underlying mechanisms are elusive. We investigated whether the reduced rate of skeletal muscle contraction-relaxation cycle that occurs after caloric restriction persists during weight recovery and could contribute to catch-up fat. Using a rat model of semistarvation-refeeding, in which fat recovery is driven by suppressed thermogenesis, we show that contraction and relaxation of leg muscles are slower after both semistarvation and refeeding. These effects are associated with (i higher expression of muscle deiodinase type 3 (DIO3 which inactivates tri-iodothyronine (T3, and lower expression of T3-activating enzyme, deiodinase type 2 (DIO2, (ii slower net formation of T3 from its T4 precursor in muscles, and (iii accumulation of slow fibers at the expense of fast fibers. These semistarvation-induced changes persisted during recovery and correlated with impaired expression of transcription factors involved in slow-twitch muscle development.We conclude that diminished muscle thermogenesis following caloric restriction results from reduced muscle T3 levels, alteration in muscle-specific transcription factors, and fast-to-slow fiber shift causing slower contractility. Energy-sparing effects persist during weight recovery and likely contribute to catch-up fat.

  16. APLICAÇÃO DO MÉTODO DE BALANÇO DE CALOR NA DETERMINAÇÃO DA TRANSPIRAÇÃO DE MUDAS DE LIMOEIRO

    Directory of Open Access Journals (Sweden)

    J.E. TREJO-CHANDIA

    1997-09-01

    Full Text Available O método de balanço de calor é usado para monitorar fluxo de seiva em plantas de diversas espécies. Neste trabalho, estudou-se o desempenho e aplicabilidade do método, em mudas de limoeiro com diâmetros em torno de 18 mm. Os sensores foram avaliados em plantas envasadas, em casa de vegetação, sob condições naturais de temperatura e radiação solar. O desempenho do método foi avaliado comparando-se o fluxo de massa computado e as medidas gravimétricas de perda de massa, fazendo-se depois, análise de regressão. Os resultados indicam que os sensores tiveram uma precisão de 8% na escala horária e 11% na escala diária. A constante de tempo foi de 12 minutos, o que é um indicativo de que o método é adequado para medir fluxo de seiva em mudas de citros com boa precisão, e suficientemente apropriado para ser usado em aplicações agronômicas e fisiológicas.The heat balance method is widely used to measure sap flow of different plant species. This work focused on the performance and applicability of the method, using 2-year old lemon plants, with 18 mm in diameter, the sensors were evaluated on potted-plants in a greenhouse under natural temperature and solar radiation conditions. The method performance was tested by comparing the computed mass flow with weight losses. A regression equation was used to analyse the data collected. The results showed that sensor precision reached 8% in the hourly scale and 11% in the daily scale. The time constant of 12 minutes indicated that the method was accurate to measure sap flow with good precision. Also we concluded that the method is adequate for agronomic and physiological use.

  17. Lower extremity muscle size and strength and aerobic capacity decrease with caloric restriction but not with exercise-induced weight loss

    Science.gov (United States)

    Weiss, Edward P.; Racette, Susan B.; Villareal, Dennis T.; Fontana, Luigi; Steger-May, Karen; Schechtman, Kenneth B.; Klein, Samuel; Ehsani, Ali A.; Holloszy, John O.

    2015-01-01

    Caloric restriction (CR) results in fat loss; however, it may also result in loss of muscle and thereby reduce strength and aerobic capacity (V̇O2 max). These effects may not occur with exercise-induced weight loss (EX) because of the anabolic effects of exercise on heart and skeletal muscle. We tested the hypothesis that CR reduces muscle size and strength and V̇O2 max, whereas EX preserves or improves these parameters. Healthy 50- to 60-yr-old men and women (body mass index of 23.5–29.9 kg/m2) were studied before and after 12 mo of weight loss by CR (n = 18) or EX (n = 16). Lean mass was assessed by dual-energy X-ray absorptiometry, thigh muscle volume by MRI, isometric and isokinetic knee flexor strength by dynamometry, and treadmill V̇O2 max by indirect calorimetry. Both interventions caused significant decreases in body weight (CR: −10.7 ± 1.4%, EX: −9.5 ± 1.5%) and lean mass (CR: −3.5 ± 0.7%, EX: −2.2 ± 0.8%), with no significant differences between groups. Significant decreases in thigh muscle volume (−6.9 ± 0.8%) and composite knee flexion strength (−7.2 ± 3%) occurred in the CR group only. Absolute V̇O2 max decreased significantly in the CR group (−6.8 ± 2.3%), whereas the EX group had significant increases in both absolute (+15.5 ± 2.4%) and relative (+28.3 ± 3.0%) V̇O2 max. These data provide evidence that muscle mass and absolute physical work capacity decrease in response to 12 mo of CR but not in response to a similar weight loss induced by exercise. These findings suggest that, during EX, the body adapts to maintain or even enhance physical performance capacity. PMID:17095635

  18. Um estudo a respeito das concepções alternativas sobre calor e temperatura

    OpenAIRE

    Köhnlein, Janete F. Klein; Peduzzi, Sônia S.

    2011-01-01

    Neste trabalho, foi realizada uma investigação que teve por objetivo verificar se um planejamento de ensino, tendo como ponto de partida as concepções alternativas dos alunos da 2ª série do Ensino Médio, resultava em uma aprendizagem mais eficiente.  Também foram identificadas, através de um teste, as similaridades entre as concepções alternativas apresentadas por estes alunos com as de três cursos de formação de professores (Magistério, Licenciatura Plena em Matemática e Licenciatura Plena e...

  19. Study of the internal heat transfer of the water flow in nucleate boiling; Estudio de la transferencia de calor del flujo interno de agua en ebullicion nucleada

    Energy Technology Data Exchange (ETDEWEB)

    Payan Rodriguez, Luis Alfredo

    2003-09-01

    In this paper the development of a research project oriented to the analysis of the heat transfer of the water flow in nucleate boiling is presented. Here a mathematical model is described to characterize the water flow in boiling condition in vertical tubes by means of which the temperature distributions in the tube wall and in the water flow are obtained, including the calculation of the pressure drop throughout the tube. In addition, a mechanistic model focused to the prediction of the critical heat flow in vertical tubes uniformly heated was modified to be applied in non-uniform heat flow conditions. The proposed mathematical models were used in a case study derived from a real problem in a thermoelectric power plant, where it was required to simulate the process of boiling in fireplace tubes of the steam generator to determine the causes of the faults that happened in a considerable number of tubes. With the obtained results it was possible to establish that the faults in the tubes of the analyzed steam generator were originated because the heat transfer rate in the fireplace reached critical values that caused the deviation of the nucleate boiling to film boiling, causing the diminution of the heat transfer coefficient with the consequent sudden increase in the tube wall temperature. [Spanish] En este trabajo se presenta el desarrollo de un proyecto de investigacion orientado al analisis de la transferencia de calor en flujo de agua en ebullicion nucleada. Aqui se describe un modelo matematico para caracterizar el flujo de agua en ebullicion en tubos verticales mediante el cual se obtienen las distribuciones de temperatura en la pared del tubo y en el flujo de agua, incluyendo el calculo de la caida de presion a lo largo del tubo. Ademas, un modelo mecanistico enfocado a la prediccion del flujo de calor critico en tubos verticales uniformemente calentados fue modificado para aplicarlo en condiciones de flujo de calor no uniforme. Los modelos matematicos

  20. Análisis exergético comparativo entre intercambiadores de calor // A comparative exergetic analysis of compact heat exchangers

    Directory of Open Access Journals (Sweden)

    Rubén Borrajo-Pérez

    2011-08-01

    Full Text Available Los intercambiadores de calor son equipos de importancia primordial en la industria y enaplicaciones domésticas en general. El trabajo está relacionado con el area de la intensificacion de latransferencia de calor en intercambiadores de calor compactos y la comparación entre diferentestipos de superficies intensificadas. La comparación es realizada a partir del análisis de la exergíadestruída por la superfície de intercambio como resultado de las perdidas por fricción y delintercambio térmico entre cuerpos con diferencia finita de temperaturas. El análisis de Segunda Leyde la Termodinámica permite identificar en que superfície de intercambio se genera mas entropía.Como resultado fundamental se obtiene la dependencia entre la exergía destruída y elespaciamiento transversal para una superfície formada por una fila de tubos elipticos a diferentesvalores del numero de Reynolds. Se identifica al intercambio térmico como la de mayor aporte a laentropía generada. Finalmente se demuestra la viabilidad de la intensificación de la transferencia decalor empleando generadores de vórtices en intercambiadores de calor.Palabras claves: generadores de vórtices, intecambiadores de calor compactos, tubos elípticos, exergía.__________________________________________________________________AbstractThe heat exchangers are important devices in both industry and household applications. This work isabout heat transfer enhancement in heat exchangers surface. Many heat transfer enhancementtechniques can be applied and then a comparative tool is needed to evaluate its performance.Thermodynamics is one of these tools and the exergetic analysis can be applied to heat exchangersurfaces. The exergy destroyed because both of thermal exchange between bodies with differenttemperatures and destroyed by friction drag is calculated. These results are used to compare heatexchanger surfaces. Heat exchanger surfaces in smooth configuration and the same surfaces

  1. Coeficientes de transferencia de calor experimental para el enfriamiento de licor en intercambiadores de placas//Experimental heat transfer coefficients for the liquor cooling in plate heat exchanger

    Directory of Open Access Journals (Sweden)

    Enrique Torres‐Tamayo

    2014-01-01

    Full Text Available La pérdida de eficiencia del proceso de enfriamiento del licor amoniacal, mediante el uso de intercambiadores de calor de placas, está asociada a imprecisiones en la estimación de los coeficientes de transferencia de calor y la acumulación de incrustaciones en la superficie de intercambio. El objetivo de la investigación es determinar los coeficientes de transferencia de calor y la influencia de lasincrustaciones en la pérdida de eficiencia de la instalación. Mediante un procedimiento iterativo se estableció la ecuación del número de Nusselt y su relación con el número de Reynolds y Prandtl. Se utilizó un diseño experimental multifactorial. Los resultados predicen el conocimiento de los coeficientespara el cálculo del número de Nusselt en ambos fluidos. Los valores de los coeficientes del licor amoniacal son inferiores, ello se debe a la presencia de componentes gaseosos. La ecuación obtenida muestra correspondencia con el modelo de Buonapane, el error comparativo es del 3,55 %.Palabras claves: intercambiador de calor de placas, coeficientes de transferencia de calor, eficiencia térmica.______________________________________________________________________________AbstractThe loss of efficiency of the ammonia liquor cooling process, by means of the plate heat exchanger, is associated to the incorrect estimate of the heat transfer coefficients and the accumulation of inlays in the exchange surface. The objective of the investigation is to determine the transfer coefficients and the influence of the inlays in the efficiency loss of the installation. By means of an iterative procedure was obtained the Nusselt number equation and the relationship with the Reynolds and Prandtl number, for it was used it a design experimental multifactorial. The results predict the knowledge of the coefficients forthe calculation of the Nusselt number for both fluids. The ammonia liquor coefficients values are inferior, due to the presence of gassy

  2. Efeitos do calor no OBLA: comparação entre ambiente quente e temperado

    Directory of Open Access Journals (Sweden)

    Cristiano Lino Monteiro de Barros

    2013-06-01

    Full Text Available O OBLA (onset of blood lactate accumulation é um método utilizado para estimar o limiar de lactato (LL. Entretanto, ainda não está claro o efeito da temperatura ambiente sobre o OBLA. O objetivo do presente estudo foi comparar o OBLA em ambiente quente (40ºC e temperado (22ºC. Nove homens (idade: 23,9±2,4 anos; massa corporal: 75,9±7,3 kg e VO2máx: 47,8±4,9 mL•kg-1•min-1 realizaram teste progressivo em cicloergômetro para determinação da potência máxima (Wmáx e do OBLA nos dois ambientes. A Wmáx (195±25W vs 225±28W e a potência no OBLA (153±30W vs 165±32W foram menores no ambiente quente do que no temperado. A frequência cardíaca no OBLA-40 foi maior do que no OBLA-22 (171±8 vs 153±10 bpm, respectivamente. Não foi observada diferença no consumo de oxigênio no OBLA-22 e OBLA-40 (31,65±5,21 vs 31,12±6,82 mL•kg-1•min-1. Estes resultados indicam que as condições ambientais influenciam a determinação do OBLA.

  3. Effect of intermittent fasting with or without caloric restriction on prostate cancer growth and survival in SCID mice.

    Science.gov (United States)

    Buschemeyer, W Cooper; Klink, Joseph C; Mavropoulos, John C; Poulton, Susan H; Demark-Wahnefried, Wendy; Hursting, Stephen D; Cohen, Pinchas; Hwang, David; Johnson, Tracy L; Freedland, Stephen J

    2010-07-01

    Caloric restriction (CR) delays cancer growth in animals, though translation to humans is difficult. We hypothesized intermittent fasting (i.e., intermittent extreme CR), may be better tolerated and prolong survival of prostate cancer (CaP) bearing mice. We conducted a pilot study by injecting 105 male individually-housed SCID mice with LAPC-4 cells. When tumors reached 200 mm(3), 15 mice/group were randomized to one of seven diets and sacrificed when tumors reached 1,500 mm(3): Group 1: ad libitum 7 days/week; Group 2: fasted 1 day/week and ad libitum 6 days/week; Group 3: fasted 1 day/week and fed 6 days/week via paired feeding to maintain isocaloric conditions to Group 1; Group 4: 14% CR 7 days/week; Group 5: fasted 2 days/week and ad libitum 5 days/week; Group 6: fasted 2 day/week and fed 5 days/week via paired feeding to maintain isocaloric conditions to Group 1; Group 7: 28% CR 7 days/week. Sera from mice at sacrifice were analyzed for IGF-axis hormones. There were no significant differences in survival among any groups. However, relative to Group 1, there were non-significant trends for improved survival for Groups 3 (HR 0.65, P = 0.26), 5 (0.60, P = 0.18), 6 (HR 0.59, P = 0.16), and 7 (P = 0.59, P = 0.17). Relative to Group 1, body weights and IGF-1 levels were significantly lower in Groups 6 and 7. This exploratory study found non-significant trends toward improved survival with some intermittent fasting regimens, in the absence of weight loss. Larger appropriately powered studies to detect modest, but clinically important differences are necessary to confirm these findings.

  4. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    Science.gov (United States)

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits.

  5. Chronological analysis of caloric restriction-induced alteration of fatty acid biosynthesis in white adipose tissue of rats.

    Science.gov (United States)

    Okita, Naoyuki; Tsuchiya, Takuro; Fukushima, Mayumi; Itakura, Kaho; Yuguchi, Keiko; Narita, Takumi; Hashizume, Yukari; Sudo, Yuka; Chiba, Takuya; Shimokawa, Isao; Higami, Yoshikazu

    2015-03-01

    The beneficial actions of caloric restriction (CR) could be mediated in part by metabolic remodeling of white adipose tissue (WAT). Recently, we suggested that CR for 6 months increased the expressions of proteins involved in de novo fatty acid (FA) biosynthesis in WAT of 9-month-old rats. Herein, we compared the CR-induced chronological alterations of the expression of mRNAs and/or proteins involved in FA biosynthesis in the WAT and liver of rats subjected to CR starting from 3 months of age and their age-matched controls fed ad libitum. The findings suggested that CR was more effective on FA biosynthesis in WAT than in liver. In WAT, CR markedly increased the expressions of mRNAs and/or proteins involved in FA biosynthesis, including sterol regulatory element-binding protein 1c (SREBP1c), a master transcriptional regulator of FA biosynthesis, throughout the experimental period. Interestingly, the CR-enhanced upregulation was temporally attenuated at 5 months of age. CR markedly increased the nuclear phosphorylated form of Akt only at 3.5 months of age. In contrast, CR significantly reduced the expression of leptin at 9 months of age. The CR-induced upregulation was not observed in obese fa/fa Zucker rats homozygous for nonfunctional leptin receptor. Collectively, these data indicate that the V-shaped chronological alterations in WAT are regulated via SREBP1c, which is probably activated by CR duration-dependent modulation of both insulin and leptin signaling. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Sterol regulatory element-binding protein-1c orchestrates metabolic remodeling of white adipose tissue by caloric restriction.

    Science.gov (United States)

    Fujii, Namiki; Narita, Takumi; Okita, Naoyuki; Kobayashi, Masaki; Furuta, Yurika; Chujo, Yoshikazu; Sakai, Masahiro; Yamada, Atsushi; Takeda, Kanae; Konishi, Tomokazu; Sudo, Yuka; Shimokawa, Isao; Higami, Yoshikazu

    2017-06-01

    Caloric restriction (CR) can delay onset of several age-related pathophysiologies and extend lifespan in various species, including rodents. CR also induces metabolic remodeling involved in activation of lipid metabolism, enhancement of mitochondrial biogenesis, and reduction of oxidative stress in white adipose tissue (WAT). In studies using genetically modified mice with extended lifespans, WAT characteristics influenced mammalian lifespans. However, molecular mechanisms underlying CR-associated metabolic remodeling of WAT remain unclear. Sterol regulatory element-binding protein-1c (Srebp-1c), a master transcription factor of fatty acid (FA) biosynthesis, is responsible for the pathogenesis of fatty liver (steatosis). Our study showed that, under CR conditions, Srebp-1c enhanced mitochondrial biogenesis via increased expression of peroxisome proliferator-activated receptor gamma coactivator-1α (Pgc-1α) and upregulated expression of proteins involved in FA biosynthesis within WAT. However, via Srebp-1c, most of these CR-associated metabolic alterations were not observed in other tissues, including the liver. Moreover, our data indicated that Srebp-1c may be an important factor both for CR-associated suppression of oxidative stress, through increased synthesis of glutathione in WAT, and for the prolongevity action of CR. Our results strongly suggested that Srebp-1c, the primary FA biosynthesis-promoting transcriptional factor implicated in fatty liver disease, is also the food shortage-responsive factor in WAT. This indicated that Srebp-1c is a key regulator of metabolic remodeling leading to the beneficial effects of CR. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  7. Estudo da Ilha de Calor na Região Metropolitana do Rio de Janeiro Usando Dados do MODIS

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    Caio Atila Pereira Sena

    2014-07-01

    Full Text Available A Região Metropolitana do Rio de Janeiro (RMRJ apresenta uma série de problemas ambientais, dentre eles, a ocorrência de Ilhas de Calor Urbanas (ICU e este trabalho tem como objetivo examinar as características da ICU na RMRJ. Para tal, foram usadas composições de 8 dias de dados de Temperatura Superficial Continental (TSC geradas pelo sensor MODIS (Moderate-resolution Imaging Spectroradiometer a bordo dos satélites Aqua e Terra no período de janeiro de 2003 a dezembro de 2010. A análise foi feita agrupando-se os dados para as diferentes estações do ano e posteriormente calculando-se a média de TSC para cada estação com o intuito de verificar a variação sazonal da ICU. Observou-se que, algumas zonas apresentaram temperaturas próximas dos 50°C durante a primavera e o verão. Ao longo do outono e do inverno as médias atingiram 40°C sobre a maior parte da região de estudo. Foram registradas amplitudes térmicas de até 25°C entre áreas com diferentes níveis de urbanização, durante a primavera. No verão a amplitude foi de 20°C entre as mesmas áreas. No outono a diferença foi de 15°C e no inverno, de 10°C.

  8. The effect of aging and caloric restriction on murine CD8+ T cell chemokine receptor gene expression

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    Mo RuRan

    2007-11-01

    Full Text Available Abstract Background The mechanism explaining the increased disease susceptibility in aging is not well understood. CD8+ T cells are crucial in anti-viral and anti-tumor responses. Although the chemokine system plays a critical role in CD8+ T cell function, very little is known about the relationship between aging and the T cell chemokine system. Results In this study we have examined the effect of aging on murine CD8+ T cell chemokine receptor gene expression. Freshly isolated splenic CD8+ T cells from old C57BL/6 mice were found to have higher CCR1, CCR2, CCR4, CCR5 and CXCR5, and lower CCR7 gene expression compared to their younger cohort. Anti-CD3/anti-CD28 stimulation elicited a similar robust chemokine receptor response from young and old CD8+ T cells. Western blot analyses confirmed elevated protein level of CCR4 and CCR5 in aged CD8+ T cells. Increases in T cell CCR1 and CCR5 expression also correlate to increased in vitro chemotaxis response to macrophage-inflammatory protein-1 α(MIP-1α. Finally, caloric restriction selectively prevents the loss of CD8+ T cell CCR7 gene expression in aging to the level that is seen in young CD8+ T cells. Conclusion These findings are consistent with the notion that aging exists in a state of low grade pro-inflammatory environment. In addition, our results provide a potential mechanism for the reported aging-associated impaired T cell lymphoid homing and allograft response, and reduced survival in sepsis.

  9. Fisetin as a caloric restriction mimetic protects rat brain against aging induced oxidative stress, apoptosis and neurodegeneration.

    Science.gov (United States)

    Singh, Sandeep; Singh, Abhishek Kumar; Garg, Geetika; Rizvi, Syed Ibrahim

    2018-01-15

    In the present study, attempts have been made to evaluate the potential role of fisetin, a caloric restriction mimetic (CRM), for neuroprotection in D-galactose (D-gal) induced accelerated and natural aging models of rat. Fisetin was supplemented (15mg/kg b.w., orally) to young, D-gal induced aged (D-gal 500mg/kg b.w subcutaneously) and naturally aged rats for 6weeks. Standard protocols were employed to measure pro-oxidants, antioxidants and mitochondrial membrane potential in brain tissues. Gene expression analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to assess the expression of autophagy, neuronal, aging as well as inflammatory marker genes. We have also evaluated apoptotic cell death and synaptosomal membrane-bound ion transporter activities in brain tissues. Our data demonstrated that fisetin significantly decreased the level of pro-oxidants and increased the level of antioxidants. Furthermore, fisetin also ameliorated mitochondrial membrane depolarization, apoptotic cell death and impairments in the activities of synaptosomal membrane-bound ion transporters in aging rat brain. RT-PCR data revealed that fisetin up-regulated the expression of autophagy genes (Atg-3 and Beclin-1), sirtuin-1 and neuronal markers (NSE and Ngb), and down-regulated the expression of inflammatory (IL-1β and TNF-α) and Sirt-2 genes respectively in aging brain. The present study suggests that fisetin supplementation may provide neuroprotection against aging-induced oxidative stress, apoptotic cell death, neuro-inflammation, and neurodegeneration in rat brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Curcumin and piperine supplementation of obese mice under caloric restriction modulates body fat and interleukin-1β.

    Science.gov (United States)

    Miyazawa, Taiki; Nakagawa, Kiyotaka; Kim, Sharon H; Thomas, Michael J; Paul, Ligi; Zingg, Jean-Marc; Dolnikowski, Gregory G; Roberts, Susan B; Kimura, Fumiko; Miyazawa, Teruo; Azzi, Angelo; Meydani, Mohsen

    2018-01-01

    Dietary bioactive compounds capable of improving metabolic profiles would be of great value, especially for overweight individuals undergoing a caloric restriction (CR) regimen. Curcumin (Cur), a possible anti-obesity compound, and piperine (Pip), a plausible enhancer of Cur's bioavailability and efficacy, may be candidate agents for controlling body fat, metabolism and low grade inflammation. 47 eight-week-old male C57BL/6 mice were fed a high fat diet (HFD) for 23 weeks to induce obesity. Then, mice were divided into 5 groups. Group 1 continued on HFD ad libitum. The other 4 groups underwent CR (reduced 10% HFD intake for 10 weeks, 20% for 20 weeks) with Cur, Pip, Cur + Pip or none of these. Percent body fat, plasma inflammatory markers associated with obesity (interferon (IFN)-γ, interleukin (IL)-10, IL-12 p70, IL-1β, IL-6 and KC/GRO), plasma Cur metabolites and liver telomere length were measured. Compared to the other groups, obese mice who underwent CR and received Cur + Pip in their diet lost more fat and had significantly lower IL-1β and KC/GRO. Tandem mass spectrometry analysis of plasma from obese mice under CR showed no difference in Cur metabolite levels between groups supplemented with Cur alone or combined with Pip. However, plasma IL-1β levels were inversely correlated with curcumin glucuronide. Minor modulation of telomere length were observed. It is plausible that supplementing the high fat diet of CR mice with Cur + Pip may increase loss of body fat and suppresses HFD induced inflammation. Combination of Cur and Pip has potential to enhance CR effects for the prevention of metabolic syndrome.

  11. Caloric restriction protects against electrical kindling of the amygdala by inhibiting the mTOR signaling pathway

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    Bryan Victor Phillips-Farfan

    2015-03-01

    Full Text Available Caloric restriction (CR has been shown to possess antiepileptic properties; however its mechanism of action is poorly understood. CR might inhibit the activity of the mammalian or mechanistic target of rapamycin (mTOR signaling cascade, which seems to participate crucially in the generation of epilepsy. Thus, we investigated the effect of CR on the mTOR pathway and whether CR modified epilepsy generation due to electrical amygdala kindling. The former was studied by analyzing the phosphorylation of adenosine monophosphate-activated protein kinase, protein kinase B and the ribosomal protein S6. The mTOR cascade is regulated by energy and by insulin levels, both of which may be changed by CR; thus we investigated if CR altered the levels of energy substrates in the blood or the level of insulin in plasma. Finally, we studied if CR modified the expression of genes that encode proteins participating in the mTOR pathway. CR increased the after-discharge threshold and tended to reduce the after-discharge duration, indicating an anti-convulsive action. CR diminished the phosphorylation of protein kinase B and ribosomal protein S6, suggesting an inhibition of the mTOR cascade. However, CR did not change glucose, β-hydroxybutyrate or insulin levels; thus the effects of CR were independent from them. Interestingly, CR also did not modify the expression of any investigated gene. The results suggest that the anti-epileptic effect of CR may be partly due to inhibition of the mTOR pathway.

  12. Climatologia e variabilidade sazonal do número de ondas de calor e de frio no Rio Grande do Sul associadas ao ENOS Climatology and seasonal variability of the number of warm and cold waves in Rio Grande do Sul associated to ENOS

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    Mári Ândrea Feldman Firpo

    2012-03-01

    Full Text Available Este trabalho investiga a variabilidade sazonal das ocorrências de ondas de frio e calor no Rio Grande do Sul e suas relações com os eventos El Niño e La Niña. Foram utilizados dados de 13 estações de superfície bem distribuídas pelo Estado, no período de 39 anos, compreendido entre 1967 e 2005. As relações entre ondas e ENOS foram obtidas a partir da análise de tabelas de contingência 2 x 2 para os meses centrais de cada estação do ano. A significância estatística foi avaliada através do teste exato de Fischer. Observou-se que a variabilidade sazonal das ondas de frio é diferente da variabilidade das ondas de calor. Ocorrem mais ondas de frio nos meses com as temperaturas mínimas mais baixas, e as ondas de calor têm comportamento mais heterogêneo. Na maioria das localidades, é em julho que as relações entre a ocorrência de ondas de calor e os eventos El Niño são mais significativas. Para La Niña e ondas de Frio, o mês com relações mais significativas foi abril. Em ambos os casos, nota-se que há defasagem entre a ocorrência dos eventos El Niño/La Niña e o seu impacto no surgimento de ondas de calor/frio.This work investigates the seasonal variability occurrence of cold and warm waves in the Brazilian State of Rio Grande do Sul and its relationships with El Niño and La Niña events. 39 years (1967-2005 temperature data series from 13 uniformly distributed meteorological stations over the State were used. The relationships between waves and ENOS were obtained from 2x2 contingence table analysis for the central months of each season. The statistical significance was evaluated using the Fisher exact test. It was observed that the seasonal variability of cold waves is different than the warm wave variability. There are more cold waves during the months with lowest minimum temperatures, and the warm waves have a more heterogeneous behavior. In most localities, the relationships between the occurrence of the warm

  13. Determinación del coeficiente global de transferencia de calor en secaderos rotativos de cáscara de limón Determination of global heat transfer coefficient in lemon peel rotary dryers

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    Marcos A. Golato

    2005-12-01

    Full Text Available En la bibliografía consultada no se encontraron trabajos de secado de cáscara de limón en secaderos rotativos. Se realizaron ensayos de medición en secaderos rotativos de cáscara de limón en una instalación agroindustrial del noroeste argentino. Se desarrolló un modelo matemático semiempírico mediante la resolución de los balances de materia y energía. Se obtuvo una correlación estadística para la predicción de los coeficientes globales volumétricos de transferencia de calor aparentes para secaderos rotativos de cáscara de limón.No papers on lemon peel drying in rotary dryers were actually found in the sources consulted. Measurement tests were carried out in the assessment of rotary dryer systems used to dehydrate lemon peel in an agroindustrial plant of Northwestern Argentina. A semiempirical mathematic model was developed solving mass and energy balances. A statistical correlation for predicting global heat transfer coefficient in rotary dryer lemon peel dehydration was obtained.

  14. Respuestas al estrés por calor en los cultivos. I. Aspectos moleculares, bioquímicos y siológicos.

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    Néstor Felipe Chaves-Barrantes

    2016-12-01

    Full Text Available El objetivo de esta revisión fue integrar los mecanismos por los cuales las plantas responden al estrés por calor a lo largo del continuo suelo-planta-atmósfera, desde una perspectiva agronómica. Esta revisión presenta las bases siológicas del estrés por calor, para lo cual se examinaron las temperaturas óptimas y los umbrales de estrés por calor en los cultivos, las metodologías para su estudio, y las respuestas moleculares, bioquímicas y siológicas de las plantas a altas temperaturas. Se describe el efecto de las altas temperaturas sobre la estructura y el metabolismo celular, la respiración y la aclimatación de la Q10, la estabilidad de las membranas, la acumulación de osmolitos compatibles, la producción de pigmentos y metabolitos secundarios, la producción de especies reactivas de oxígeno (ROS y enzimas antioxidantes, la producción de proteínas de estrés, y el efecto sobre la fotosíntesis y la partición de asimilados. Además, se discuten los cambios hormonales que regulan la respuesta de las plantas en el campo, su señalización y la aclimatación al estrés térmico.

  15. The nature of heat: after two centuries, will it be that the caloric theory is still in some way an attractive idea or, even, useful?

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    Antônio Bráz de Pádua

    2009-03-01

    Full Text Available In the beginning of the 19th Century, there were two theories absolutely different on the nature of the heat: the Mechanical Theory of the Heat and the Caloric Theory. For the first theory, heat was considered as ‘a vibration’ of the atoms that compose the matter. Thus, the temperature represented the intensity of those vibrations and their propagation was a transfer of heat. When two bodies of different temperatures were put in contact, the atoms of the hottest body communicated part of its vibrations to that of the coldest body by means of collisions until the atoms of both bodies vibrated with the same intensities. For the second theory, the heat was considered a subtle fluid that filled the interior of the bodies. Spread all over the nature, that fluid was propagated or conserved by the bodies according to their properties and temperatures. Before being replaced by the conception of heat as a form of energy, in the middle of the 19th Century, the Caloric Theory reached great successes with the works of Jean-Baptiste Fourier (1768 – 1830 in 1822, Sadi Carnot (1796 – 1832, in 1824 and Émile Clapeyron (1799 – 1864 in 1834. By means of a careful revision of the analytic results of Clapeyron, developed under the basis of the Caloric Theory, we propose in this work to re-adapt these results and to compare them with current experimental data and theories, and to show that we can still understand some characteristics of the thermal phenomena, without considering heat as a form of energy. Especially in the study of the gases, we could obtain objective and precise information about absorption and liberation of heat in the isothermal processes, efficiency of the thermal machine of Carnot and the relationship among specific heats.

  16. A maternal high-fat/high-caloric diet delays reflex ontogeny during lactation but enhances locomotor performance during late adolescence in rats.

    Science.gov (United States)

    Cadena-Burbano, Erika Vanesa; Cavalcanti, Carolina Cadete Lucena; Lago, Amanda Braz; Benjamim, Raquel de Arruda Campos; Oliveira, Thaynan Raquel Dos Prazeres; Silva, Jacqueline Maria; Manhães-De-Castro, Raul; Da Silva Aragão, Raquel

    2017-07-28

    The main goal of the present study was to investigate the effects of two maternal high-fat diets with different energy densities on the somatic growth, reflex ontogeny, and locomotor activity of offspring. Twenty-nine female Wistar rats (220-250 g) were mated and grouped into three different dietary conditions: control (n = 11, AIN-93G diet, 3.6 kcal/g), high-fat/high-caloric (HH, n = 9, 51% of the calories from fat, 4.62 kcal/g), and high-fat/isocaloric (HI, n = 9, 51% of the calories from fat, 3.64 kcal/g). The fat source was mainly lard. The dietary groups were maintained during gestation and lactation. From postnatal day 1 (PND1) until weaning, the somatic growth, maturation of physical features, and reflex ontogeny of the male pups were evaluated. The locomotor activity was evaluated in an open field at PND8, PND14, PND17, PND21, PND30, PND45, and PND60. HH dams had a lower food intake but no difference in caloric intake or body weight gain. The HH pups had higher body weights, greater tail and body lengths, and an increased axis of the head at weaning. The prediction of ear unfolding, delayed palmar grasp, and cliff avoidance maturation were also observed in the HH offspring. At PND60, the HH pups showed an increased average speed as well as an average potency and kinetic energy in the open field. A high-fat/high-caloric maternal diet increases somatic growth, predicts the maturation of physical features, and delays reflex ontogeny during lactation, and it enhances motor performance during late adolescence. A maternal HI diet does not elicit the same influences on offspring development compared with the HH diet.

  17. Impact of adiposity, age, sex and maternal feeding practices on eating in the absence of hunger and caloric compensation in preschool children.

    Science.gov (United States)

    Remy, E; Issanchou, S; Chabanet, C; Boggio, V; Nicklaus, S

    2015-06-01

    Between the ages of 3 and 5 years, children may become less responsive to internal cues of satiation and more responsive to external cues, which may induce overeating and lead to weight gain. This study aimed to compare eating in the absence of hunger (EAH) and caloric compensation in 3- to 6-year-old children, and to relate the measurements with children's adiposity, age, sex and maternal feeding practices. According to a within-subject three sequential condition design, food intake in children (n=236) was measured at lunch during three sessions, once a week. The same meal (565 kcal) was offered at each session. The first session (control) was only composed of the meal. Thirty minutes before the second meal, children were offered an energy preload (137 kcal; caloric compensation condition). Ten minutes after the third meal, children were exposed to a post-meal snack (430 kcal; EAH condition). Individual caloric compensation score (COMPX) and EAH score were calculated. Maternal characteristics were measured by questionnaire. Child anthropometrics were measured by a medical doctor. On average, children compensated 52±4% of the energy preload and ate 24±1% of the energy provided by their meal in the absence of hunger. COMPX and EAH score were not correlated and did not vary with children's adiposity or age. EAH score was higher in boys (P=0.006). Maternal use of food as reward was associated with higher EAH score (P=0.01) but greater COMPX (P=0.005). As early as the age of 3 years children did not fully compensate the energy brought by a snack and ate in the absence of hunger. Parents should be advised to avoid these situations where overeating may occur and to limit the use of food as reward.

  18. FLUJO INTERNO MIXTO CON DIFUSIÓN DOBLE DE CALOR Y MASA EN UNA CAVIDAD RECTANGULAR MIXED INTERNAL FLOW WITH DOUBLE DIFFUSION OF HEAT AND MASS

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    Carlos H Salinas Lira

    2008-09-01

    Full Text Available El presente trabajo muestra resultados de transporte de calor y masa (Doble al interior de una cavidad rectangular ocasionado por un flujo convectivo forzado y natural (Mixto. El modelo matemático consta de las ecuaciones de Navier-Stokes para describir el flujo laminar de un fluido incompresible. Además es modelado el transporte de calor y masa a través de dos ecuaciones diferenciales lineales de segunda orden, incorporando en forma lineal los efectos de los gradientes de concentración y de temperaturas. El modelo matemático es resuelto numéricamente a través del Método de Volúmenes Finitos descrito en coordenadas curvilíneas y variables colocalizadas, representando los términos difusivos a través de diferencia central y usando un esquema potencial para los términos convectivos. Se muestran resultados originales de patrones de flujo: Isotermas, isoconcentraciones y números de Nusselt y de Sherwood en regiones características para el problema de flujo interno mixto con difusión de calor y masa.The present work shows the relationship of the transport of heat and mass (double in a rectangular cavity caused by a forced and natural convection. The mathematical model consists of the Navier-Stokes equations to describe the incompressible laminar flow. The transport of heat and mass are modelled through two second order no-linear differential equations, incorporating in linear way the effects of gradients of concentrations and temperature. The mathematical problems is solved numerically through the Finite Volumes Method, in curvilinear coordinated and co-located variables, representing the diffusion through central difference and using a potential schemes for the convection terms. Original results of flow models are shown: Isotherms, isoconcentrations and numbers of Nusselt and Sherwood in characteristic regions for the mixed internal flow problem with heat and mass are shown.

  19. IDENTIFICAÇÃO DE ILHAS DE CALOR POR MEIO DE SENSORIAMENTO REMOTO: ESTUDO DE CASO NO MUNICÍPIO DE GOIÂNIA – GO/2001

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    Diego Tarley Ferreira Nascimento

    2009-06-01

    Full Text Available No presente trabalho são utilizadas técnicas de sensoriamento remoto para identificação e análise do fenômeno de ilhas de calor em Goiânia-GO, tendo como recorte temporal o ano de 2001. Foi utilizada a proposta metodológica de Monteiro (1976, do Sistema de Clima Urbano – SCU, em particular o subsistema Termodinâmico, visando proceder a uma análise do funcionamento, desempenho e organização do fenômeno de ilhas de calor. A elaboração do trabalho baseou-se na classificação da cobertura do solo e em um mapeamento do campo térmico do município de Goiânia, por meio das imagens das bandas 3, 4, 5 e 6 (banda termal do Landsat 7, nas quais foram considerados como instrumentos de análise: a urbanização, as características geoecológicas (topografia e o sistema meteorológico (clima regional. Os resultados demonstram que o fenômeno de ilha de calor é constatado no município de Goiânia, havendo diferenças de temperatura de até 10°C entre a área urbana e a rural do município, sendo possível caracterizar determinados usos antrópicos (classes de cobertura do solo e intervalos altimétricos como potencializadores de maiores valores de temperatura.

  20. Tackling the aging process with bio-molecules: a possible role for caloric restriction, food-derived nutrients, vitamins, amino acids, peptides, and minerals.

    Science.gov (United States)

    Dabhade, Prachi; Kotwal, Swati

    2013-01-01

    Aging is a multifactorial process leading to general deterioration in many tissues and organs, accompanied by an increased incidence and severity of a wide variety of chronic, incurable, and often fatal diseases. A possibility of slowing down the aging process and improving the quality of life in old age by nutritional intervention has renewed the interest of the scientific world in anti-aging therapies. These include potential dietary interventions, adherence to nutrition, hormonal and cell-based therapies, genetic manipulations, and anti-aging supplements or nutrients. This review addresses strategies to slow the aging process by caloric restriction and the use of nutritional supplements.

  1. Growth of very low birth weight infants fed with milk from a human milk bank selected according to the caloric and protein value

    OpenAIRE

    Marisa Matta Aprile; Rubens Feferbaum; Nerli Andreassa; Claudio Leone

    2010-01-01

    OBJECTIVE: To describe growth and clinical evolution of very low birth weight infants fed during hospital stay with milk from a human milk bank according to the caloric-protein value. METHOD: Forty very low birth weight infants were included: 10 were fed milk from their own mothers (GI), and 30 were fed human milk bank > 700 cal/L and 2 g/dL of protein. Growth curves were adjusted using nonlinear regression to the measured growth parameters. RESULTS: full enteral diet was reached in 6.3 da...

  2. Direct experimental evidence for a negative heat capacity in the liquid-to-gas like phase transition in hydrogen cluster ions backbending of the caloric curve

    CERN Document Server

    Gobet, F; Carré, M; Farizon, B; Farizon, M; Gaillard, M J; Maerk, T D; Scheier, P

    2002-01-01

    By (i) selecting specific decay reactions in high energy collisions (60 keV/amu) of hydrogen cluster ions with a helium target (utilizing event-by-event data of a recently developed multi-coincidence experiment) and by (ii) deriving corresponding temperatures for these microcanonical cluster ensembles (analyzing the respective fragment distributions) we are able to construct caloric curves for ii sub 3 sup + (ii sub 2) sub m cluster ions (6 <= m <= 14). All individual curves and the mean of these curves show a backbending in the plateau region thus constituting direct evidence for a negative microcanonical heat capacity in the liquid-to-gas like transition of these finite systems.

  3. Modelado de la transferencia de calor e índices de calidad durante el escaldado convencional y asistido por ultrasonidos de champiñones.

    OpenAIRE

    LESPINARD, ALEJANDRO; Bon Corbín, José; Carcel Carrión, Juan Andrés; Benedito Fort, José Javier; Mascheroni, Rodolfo Horacio

    2013-01-01

    En la industria de los alimentos, el uso de ultrasonidos (US) en combinación con procesos convencionales ofrece nuevas posibilidades para la mejora de los procesos de alimentos, que van desde el ahorro de energía a aumentos en el rendimiento del proceso o la calidad del producto; en este sentido ha demostrado ser una tecnología emergente que permite mejorar la transferencia de calor y materia. No obstante, aún es necesario realizar estudios concretos para los diferentes procesos y/o productos...

  4. Calores de Solución y Propiedades Termodinámicas Relacionadas: Un método Gráfico General de Cálculo

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    Alfredo Gómez O.

    2009-07-01

    Full Text Available Se presenta un método gráfico de cálculo con el cual es posible evaluar a partir de datos de calor de solución. diferentes propiedades termodinámicas de interés tales como: caloresres diferenciales de solución del soluto y del solvente. A HD,P 2 V ^ HOIF.I • calor de solución a dilución infinita A tH°; entalpias molares parciales relativas del soluto y del solvente. Lj y L,. y la entalpia molar aparente relativa, L^. El método está basado en la representación gráfica del calor integral de solución expresado por mol de soluto, A H||,fr.2 en función de la relación entre el número de moles de solvente y soluto, n^/nj. Cuando k>s datos experimentales de calor de solución son tomados hasta alta dilución, puede obtenerse con precisión el vak>r de A H°, con to cual el diagrama propuesto corresponde también a la representación gráfica de(^L2 en función de n^/nj. Se discute el significado f fsk» de las propiedades consideradas así como las relaciones existentes entre ellas. El diagrama propuesto presenta ventajas ya que además de su carácter más general, resulta más preciso y conveniente que k>s métodos particulares comúnmente empleados, especialmente en la evaluación de las propiedades citadas para el caso del soluto en soluciones muy diluidas. de(^L2 en función de n^/nj. Se discute el signifteado f fsk» de las propiedades conskJeradas asi como las relaciones existentes entre ellas. El diagrama propuesto presenta ventajéis ya que además de su caráctermás general, resulta más preciso y conveniente que k>s métodos particulares comúnmente empleados, especialmente en la evaluackin de las propiedades citadas para el caso del soluto en soluctones muy diluidas.

  5. El fenómeno de la isla de calor en dos ciudades turísticas. Los casos de Ibiza y Lloret de Mar

    OpenAIRE

    Serra Pardo, Juan

    2016-01-01

    [spa] El estudio del clima urbano ha permitido analizar la modificación que las ciudades ejercen sobre el clima regional a escala local, especialmente la alteración térmica que supone. Esta alteración, conocida con el nombre de isla de calor urbana (ICU), es el elemento más significativo y mejor conocido del clima urbano. De este modo, desde diferentes disciplinas se ha estudiado el fenómeno, estableciendo sus características, causas, impactos y consecuencias, en primer lugar, para luego desa...

  6. Uma formulação de elementos finitos estabilizada de segunda-ordem no tempo para escoamentos viscosos com transferência de calor

    OpenAIRE

    CURY, Marcos Filardi

    2011-01-01

    Com os problemas de aquecimento global e a busca por fontes energéticas limpas, o aumento do emprego de energia nuclear é esperado. Assim, o desenvolvimento de tecnologias e estudos científicos para o uso de usinas nucleares é imprescindível, em particular na área de engenharia de reatores. No desenvolvimento de reatores nucleares, a mecânica de fluidos e a transferência de calor assumem papel de destaque. A fluidodinâmica computacional computacional, conhecida como CFD a partir da sigla em I...

  7. Modelo de transmisión de calor por radiación en una piscina de combustible gastado mediante TRACE

    OpenAIRE

    Sanchez Saez, Francisco; Carlos Alberola, Sofía; Martorell Alsina, Sebastián Salvador; Villanueva López, José Felipe

    2013-01-01

    El trabajo desarrollado consiste en la simulación termohidráulica de una piscina de combustible gastado al producirse un transitorio de pérdida de refrigerante con pérdida de refrigeración a través del canal de transferencia. La simulación se realiza con el código Best Estimate TRACE. Para seguir la evolución del comportamiento de la piscina, una variable importante a seguir es la temperatura de vaina, cuya evolución depende del calor que consiga emitir. En esta simulación se h...

  8. Impact of Age, Caloric Restriction, and Influenza Infection on Mouse Gut Microbiome: An Exploratory Study of the Role of Age-Related Microbiome Changes on Influenza Responses

    Directory of Open Access Journals (Sweden)

    Jenna M. Bartley

    2017-09-01

    Full Text Available Immunosenescence refers to age-related declines in the capacity to respond to infections such as influenza (flu. Caloric restriction represents a known strategy to slow many aging processes, including those involving the immune system. More recently, some changes in the microbiome have been described with aging, while the gut microbiome appears to influence responses to flu vaccination and infection. With these considerations in mind, we used a well-established mouse model of flu infection to explore the impact of flu infection, aging, and caloric restriction on the gut microbiome. Young, middle-aged, and aged caloric restricted (CR and ad lib fed (AL mice were examined after a sublethal flu infection. All mice lost 10–20% body weight and, as expected for these early time points, losses were similar at different ages and between diet groups. Cytokine and chemokine levels were also similar with the notable exception of IL-1α, which rose more than fivefold in aged AL mouse serum, while it remained unchanged in aged CR serum. Fecal microbiome phyla abundance profiles were similar in young, middle-aged, and aged AL mice at baseline and at 4 days post flu infection, while increases in Proteobacteria were evident at 7 days post flu infection in all three age groups. CR mice, compared to AL mice in each age group, had increased abundance of Proteobacteria and Verrucomicrobia at all time points. Interestingly, principal coordinate analysis determined that diet exerts a greater effect on the microbiome than age or flu infection. Percentage body weight loss correlated with the relative abundance of Proteobacteria regardless of age, suggesting flu pathogenicity is related to Proteobacteria abundance. Further, several microbial Operational Taxonomic Units from the Bacteroidetes phyla correlated with serum chemokine/cytokines regardless of both diet and age suggesting an interplay between flu-induced systemic inflammation and gut microbiota. These

  9. Energía termofotovoltaica: la conversión fotovoltaica del calor y su aplicación en sistemas de almacenamiento de energía

    OpenAIRE

    Datas Medina, Alejandro

    2015-01-01

    Del mismo modo que una célula solar convierte la luz del sol en electricidad, una célula termofotovoltaica convierte en electricidad la radiación térmica que emiten objetos incandescentes. Es decir, realizan una conversión directa del calor en electricidad, sin necesidad de emplear partes móviles ni fluidos. Entre las muchas aplicaciones de esta tecnología, en el Instituto de Energía Solar de la UPM estamos trabajando en un nuevo concepto de almacenamiento de energía térmica que utiliza silic...

  10. Simulación numérica de flujo de aire y transferencia de calor en un enfriador vertical con puerta panorámica

    OpenAIRE

    Narváez Buestán, Freddy Eduardo

    2017-01-01

    En este proyecto de investigación se analizan los flujos de aire y transferencia de calor en el interior de un Enfriador vertical. El aire sale por el cobertor y se visualiza mediante el software Ansys Fluent como el diseño influye en la distribución de flujo. Se propone una mejora en el diseño del Cobertor optimizando la distribución del flujo. In this research project the air flows and heat transfer inside a Vertical Cooler are analyzed. The air comes out through the cover panel freez...

  11. La recuperación termoeléctrica del calor residual, una fuente de energía ambientalmente amigable

    OpenAIRE

    Rodríguez, Julio E.

    2012-01-01

    El incremento del precio de los combustibles fósiles acompañado por el deterioro medioambiental asociado al calentamiento global generó un incremento en la actividad científica dirigida a identificar y desarrollar fuentes de potencia eléctrica no contaminantes. En este sentido, la conversión directa de energía térmica en eléctrica mediante dispositivos termoeléctricos utilizando calor residual como fuente de calentamiento, podría contribuir a solucionar los problemas energéticos de la socieda...

  12. Trocador de calor e umidade: proteção contra infecções pulmonares? Estudo piloto Heat and moisture exchanger: protection against lung infections? Pilot study

    OpenAIRE

    Luciana Alcoforado; Daniela Paiva; Filipe Souza da Silva; André Martins Galvão; Valdecir Galindo Filho; Daniella Cunha Brandão; Heloísa Ramos Lacerda; Armele Dornelas de Andrade

    2012-01-01

    O objetivo deste trabalho foi realizar um estudo bacteriológico comparativo entre os sistemas de umidificação aquoso aquecido (UAA) e filtro trocador de calor e umidade (FTCU) quanto à colonização bacteriana e a incidência de infecção respiratória em pacientes submetidos à ventilação mecânica (VM). Trata-se de uma pesquisa prospectiva, controlada e randomizada, na qual 15 pacientes internados na Unidade de Terapia Intensiva (UTI) foram distribuídos em dois grupos. O primeiro fez uso de UAA (n...

  13. Perfiles de temperatura generados por fuentes esféricas de calor durante el tratamiento del cáncer por hipertermia local

    OpenAIRE

    Giordano, Mauricio A.; Gutiérrez, Gustavo; Massa, Julio C.

    2011-01-01

    En este trabajo se derivan soluciones analíticas para el modelo de Pennes de difusión de calor en medios biológicos usando funciones de Green. El objetivo es predecir los perfiles de temperatura que se pueden obtener en tumores de forma esférica durante el tratamiento del cáncer por hipertermia usando fluidos magnéticos. El dominio matemático consta de dos regiones, la interna se corresponde con el tejido canceroso de dimensión finita; y la externa con tejido sano que se extiende ...

  14. Impacto ecológico de los Intercambiadores de calor de tubo y coraza; Ecological impact of Shell and tube heat exchangers

    Directory of Open Access Journals (Sweden)

    Maida Bárbara Reyes Rodríguez

    2015-04-01

    Full Text Available Los intercambiadores de calor de tubo y coraza son de los equipos más importantes en la industria. Su diseño termodinámico se basa en el coeficiente global de transferencia de calor y la caída de presión total. En 2007 se estableció una nueva propiedad termodinámica denominada “Entransía”, que expresa la capacidad de un cuerpo de transferir calor. A la pérdida de esa capacidad se le denomina “Disipación de Entransía”. Para evaluar el impacto ecológico de las máquinas térmicas, Angulo-Brown creó en 1991 la llamada función ecológica. En el presente trabajo se combinó la disipación de entransía con la función ecológica y se creó una nueva expresión para evaluar el impacto ambiental de los intercambiadores de calor. Se realizó además la optimización muti-objetivo de estos equipos. Fueron utilizadas como funciones objetivo la función ecológica y el costo. Para realizar la optimización se utilizó el método de los Algoritmos Genéticos.Shell and tube heat exchangers are ones the most important equipment in the industry. Their thermodynamic design is based on the global heat transference coefficient and the pressure drop. In 2007 was settled a new thermodynamic property denominated “Entransy”, which expresses the capacity of a body to transfer heat. The loss of this capacity is denominated “Entransy Dissipation”. For evaluating the ecological impact of thermal machines, Angulo-Brown created in 1991 the “ecological function”. In this paper the“entransy dissipation” and the ecological function were combined and a new expression for evaluating the ecological impact of shell and tube heat exchangers was created. A multi-objective optimization of this equipment wasalso realized. The ecological function and the cost wereused as objective functions. For carry out the optimization the method of the Genetic Algorithms was used.

  15. Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial1234

    Science.gov (United States)

    Turner-McGrievy, Gabrielle; Lyons, Elizabeth; Stevens, June; Erickson, Karen; Polzien, Kristen; Diamond, Molly; Wang, Xiaoshan; Popkin, Barry

    2012-01-01

    Background: Replacement of caloric beverages with noncaloric beverages may be a simple strategy for promoting modest weight reduction; however, the effectiveness of this strategy is not known. Objective: We compared the replacement of caloric beverages with water or diet beverages (DBs) as a method of weight loss over 6 mo in adults and attention controls (ACs). Design: Overweight and obese adults [n = 318; BMI (in kg/m2): 36.3 ± 5.9; 84% female; age (mean ± SD): 42 ± 10.7 y; 54% black] substituted noncaloric beverages (water or DBs) for caloric beverages (≥200 kcal/d) or made dietary changes of their choosing (AC) for 6 mo. Results: In an intent-to-treat analysis, a significant reduction in weight and waist circumference and an improvement in systolic blood pressure were observed from 0 to 6 mo. Mean (±SEM) weight losses at 6 mo were −2.5 ± 0.45% in the DB group, −2.03 ± 0.40% in the Water group, and −1.76 ± 0.35% in the AC group; there were no significant differences between groups. The chance of achieving a 5% weight loss at 6 mo was greater in the DB group than in the AC group (OR: 2.29; 95% CI: 1.05, 5.01; P = 0.04). A significant reduction in fasting glucose at 6 mo (P = 0.019) and improved hydration at 3 (P = 0.0017) and 6 (P = 0.049) mo was observed in the Water group relative to the AC group. In a combined analysis, participants assigned to beverage replacement were 2 times as likely to have achieved a 5% weight loss (OR: 2.07; 95% CI: 1.02, 4.22; P = 0.04) than were the AC participants. Conclusions: Replacement of caloric beverages with noncaloric beverages as a weight-loss strategy resulted in average weight losses of 2% to 2.5%. This strategy could have public health significance and is a simple, straightforward message. This trial was registered at clinicaltrials.gov as NCT01017783. PMID:22301929

  16. The effects of exercise training and caloric restriction on the cardiac oxytocin natriuretic peptide system in the diabetic mouse

    Directory of Open Access Journals (Sweden)

    Broderick TL

    2017-01-01

    Full Text Available Tom L Broderick,1 Marek Jankowski,2 Jolanta Gutkowska2 1Department of Physiology, Laboratory of Diabetes and Exercise Metabolism, Midwestern University, Glendale, AZ, USA; 2Department of Medicine, Laboratory of Cardiovascular Biochemistry, Centre Hospitalier de l‘Université de Montréal-Hôtel-Dieu, Montréal, QC, Canada Background: Regular exercise training (ET and caloric restriction (CR are the frontline strategies in the treatment of type 2 diabetes mellitus with the aim at reducing cardiometabolic risk. ET and CR improve body weight and glycemic control, and experimental studies indicate that these paradigms afford cardioprotection. In this study, the effects of combined ET and CR on the cardioprotective oxytocin (OT–natriuretic peptide (NP system were determined in the db/db mouse, a model of type 2 diabetes associated with insulin resistance, hyperglycemia, and obesity. Methods: Five-week-old male db/db mice were assigned to the following groups: sedentary, ET, and ET + CR. Nonobese heterozygote littermates served as controls. ET was performed on a treadmill at moderate intensity, and CR was induced by reducing food intake by 30% of that consumed by sedentary db/db mice for a period of 8 weeks. Results: After 8 weeks, only ET + CR, but not ET, slightly improved body weight compared to sedentary db/db mice. Regardless of the treatment, db/db mice remained hyperglycemic. Hearts from db/db mice demonstrated reduced expression of genes linked to the cardiac OT–NP system. In fact, compared to control mice, mRNA expression of GATA binding protein 4 (GATA4, OT receptor, OT, brain NP, NP receptor type C, and endothelial nitric oxide synthase (eNOS was decreased in hearts from sedentary db/db mice. Both ET alone and ET + CR increased the mRNA expression of GATA4 compared to sedentary db/db mice. Only ET combined with CR produced increased eNOS mRNA and protein expression. Conclusion: Our data indicate that enhancement of eNOS by combined

  17. Hombre, calor y aislamiento

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1961-11-01

    Full Text Available Con los nuevos tipos estructurales y con los adelantos de las ciencias biológicas en lo que se refiere a los procesos orgánicos, mis ideas sobre aislamiento, y las de casi todos los demás arquitectos y constructores, han sufrido una evolución interesantísima en los últimos veinticinco años. Y me complace subrayar que los que, como yo, estudiamos el decorado humano, podemos hacer mucho en beneficio de nuestros clientes. No hace aún mucho tiempo toda la protección de una casa contra el peligro de transferencia térmica se confiaba exclusivamente a muros y cubiertas no aislantes. Los propietarios se limitaban a culpar al tiempo de su falta de confort. Pero esta falta de comodidad en cuanto a calefacción no era la única consecuencia; tras ella aparecían daños de efectos duraderos y patológicos.

  18. Clinical vestibular testing assessed with machine-learning algorithms.

    Science.gov (United States)

    Priesol, Adrian J; Cao, Mengfei; Brodley, Carla E; Lewis, Richard F

    2015-04-01

    Dizziness and imbalance are common clinical problems, and accurate diagnosis depends on determining whether damage is localized to the peripheral vestibular system. Vestibular testing guides this determination, but the accuracy of the different tests is not known. To determine how well each element of the vestibular test battery segregates patients with normal peripheral vestibular function from those with unilateral reductions in vestibular function. Retrospective analysis of vestibular test batteries in 8080 patients. Clinical medical records were reviewed for a subset of individuals with the reviewers blinded to the vestibular test data. A group of machine-learning classifiers were trained using vestibular test data from persons who were "manually" labeled as having normal vestibular function or unilateral vestibular damage based on a review of their medical records. The optimal trained classifier was then used to categorize patients whose diagnoses were unknown, allowing us to determine the information content of each element of the vestibular test battery. The information provided by each element of the vestibular test battery to segregate individuals with normal vestibular function from those with unilateral vestibular damage. The time constant calculated from the rotational test ranked first in information content, and measures that were related physiologically to the rotational time constant were 10 of the top 12 highest-ranked variables. The caloric canal paresis ranked eighth, and the other elements of the test battery provided minimal additional information. The sensitivity of the rotational time constant was 77.2%, and the sensitivity of the caloric canal paresis was 59.6%; the specificity of the rotational time constant was 89.0%, and the specificity of the caloric canal paresis was 64.9%. The diagnostic accuracy of the vestibular test battery increased from 72.4% to 93.4% when the data were analyzed with the optimal machine-learning classifier

  19. [Otolith function tests--a differentiated, quality-assured screening system].

    Science.gov (United States)

    Düwel, P; Walther, L E; Sanders, M; Ilgner, J; Westhofen, M

    2005-09-01

    More than 30% of all otogenic vestibular disorders are related to isolated macular dysfunction. Videooculographic examination techniques for the otolith-ocular reflex, e. g. by means of eccentric rotation tests, are not widely used in clinical routine as these put a considerable strain on technical and staff resources. Thus, there is a considerable risk of "false negative" classification of vertigo disorders being labelled as "non-otogenic". By means of vestibular-evoked myogenic potentials (VEMPs) and caloric irrigation in prone and supine position, several examination techniques for a side-related investigation of macula-induced vestibulo-ocular reflexes are available. The objective of this study is to compare and evaluate these techniques as screening tests. In 32 patients with vestibular disorders we performed investigations for VEMPs, eccentric rotation tests, as well as caloric irrigation for macular reaction in prone and supine position. In addition, we performed other audiologic and vestibular function tests which were complemented by the clinical course in order to differentiate each case between otogenic and non-otogenic vertigo with or without macular affection. The technical feasibility as well as patients' acceptance for VEMP testing is better than for eccentric rotation tests. The sensitivity index for VEMPs (89%) as well as for caloric irrigation in prone and supine position for macular examination (71%) is satisfactory. However, the specificity of VEMPs is inferior (53%) to eccentric rotation (100%). Both the examination for VEMPs as well as caloric macular testing in prone and supine position carry features which make them feasible for screening, even though these two procedures test for two different parts of the otolith system. However, to confirm a diagnosis and to set up a therapeutic concept for macular function disorders, eccentric rotation should be added.

  20. Modelamiento y simulación del efecto de la entrada de calor en la penetración de una junta soldada

    Directory of Open Access Journals (Sweden)

    Lina Gómez

    2003-01-01

    Full Text Available En esta investigación se realizó el simulador SimVol, en el cual se experimentó con el fin de encontrar una relación entre la entrada de calor y la penetración de la junta soldada. SimVol se basó en un modelo en 2D, que describe el flujo de calor y el flujo de metal líquido en el charco de una soldadura realizada con el proceso GTAW (Gas Tungsten Arc Welding. En el modelo matemático se incluyen las ecuaciones de Navier-Stokes y la ecuación de energía, las cuales constituyen un sistema de ecuaciones diferenciales parciales de segundo orden, no-lineales, no homogéneas y transitorias. El modelo numérico se desarrolla en Volúmenes Finitos en un esquema totalmente implícito, con malla regular y escalonada; además, debido al desconocimiento del campo de presión es necesario utilizar el algoritmo SIMPLE (Semi-Implicit Method for Pressure-Linked Equations. La investigación también incluye una serie de experimentos que permitieron validar el modelo planteados.

  1. Adequate Nutrition May Get You Home: Effect of Caloric/Protein Deficits on the Discharge Destination of Critically Ill Surgical Patients.

    Science.gov (United States)

    Yeh, D Dante; Fuentes, Eva; Quraishi, Sadeq A; Cropano, Catrina; Kaafarani, Haytham; Lee, Jarone; King, David R; DeMoya, Marc; Fagenholz, Peter; Butler, Kathryn; Chang, Yuchiao; Velmahos, George

    2016-01-01

    Macronutrient deficit in the surgical intensive care unit (ICU) is associated with worse in-hospital outcomes. We hypothesized that increased caloric and protein deficit is also associated with a lower likelihood of discharge to home vs transfer to a rehabilitation or skilled nursing facility. Adult surgical ICU patients receiving >72 hours of enteral nutrition (EN) between March 2012 and May 2014 were included. Patients with absolute contraindications to EN, protein deficit (APACHE II), and initiation of EN were not significantly different between groups. On logistic regression, adjusting for BMI and APACHE II score, the high-caloric and protein-deficit groups were less likely to be discharged home (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.08-0.96; P = .04 and OR, 0.29; 95% CI, 0.0-0.89, P = .03, respectively). In surgical ICU patients, inadequate macronutrient delivery is associated with lower rates of discharge to home. Improved nutrition delivery may lead to better clinical outcomes after critical illness. © 2015 American Society for Parenteral and Enteral Nutrition.

  2. Energy saving in heat exchangers of industrial refrigeration systems; Ahorro de energia en intercambiadores de calor en los sistemas de refrigeracion industrial

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, A.; Romero Paredes, Hernando; Ambriz, Juan Jose [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1994-12-31

    This paper presents the energy losses of the heat exchangers utilized in industrial refrigeration systems . The effects of the different scaling products on the heat transfer rates are presented and the energy not transferred because of them is evaluated. A simplified method for the evaluation is developed and applied to the evaporators and condensers more frequently employed in the industrial refrigeration systems. The internal and external heat transfer coefficients are evaluated in different types of heat exchangers. The energy losses as a function of the scale thickness on the heat exchanger is shown. [Espanol] El trabajo presenta las perdidas energeticas que se tienen en los intercambiadores de calor usados en los sistemas de refrigeracion industrial. Se presentan los efectos que tienen los diferentes incrustantes en las tasas de transferencia de calor y se evalua la energia que no se transfiere causada por aquellos. Se desarrolla un metodo simplificado de evaluacion y se aplica a los evaporadores y condensadores mas comunes empleados en los sistemas de refrigeracion industrial. Se evaluan los coeficientes internos y externos en diferentes tipos de intercambiadores. Se muestran las perdidas energeticas en funcion del espesor del incrustante en la pared del intercambiador.

  3. Observational study of caloric and nutrient intake, bone density, and body composition in infants and children with spinal muscular atrophy type I.

    Science.gov (United States)

    Poruk, Katherine E; Davis, Rebecca Hurst; Smart, Abby L; Chisum, Benjamin S; Lasalle, Bernie A; Chan, Gary M; Gill, Gurmail; Reyna, Sandra P; Swoboda, Kathryn J

    2012-11-01

    Clinical experience supports a critical role for nutrition in patients with spinal muscular atrophy (SMA). Three-day dietary intake records were analyzed for 156 visits in 47 SMA type I patients, 25 males and 22 females, ages 1month to 13years (median 9.8months) and compared to dietary reference intakes for gender and age along with anthropometric measures and dual-energy X-ray absorptiometry (DEXA) data. Using standardized growth curves, twelve patients met criteria for failure to thrive (FTT) with weight for age <3rd percentile; eight met criteria based on weight for height. Percentage of body fat mass was not correlated with weight for height and weight for age across percentile categories. DEXA analysis further demonstrated that SMA type I children have higher fat mass and lower fat free mass than healthy peers (p<0.001). DEXA and dietary analysis indicates a strong correlation with magnesium intake and bone mineral density (r=0.65, p<0.001). Average caloric intake for 1-3years old was 68.8±15.8kcal/kg - 67% of peers' recommended intake. Children with SMA type I may have lower caloric requirements than healthy age-matched peers, increasing risk for over and undernourished states and deficiencies of critical nutrients. Standardized growth charts may overestimate FTT status in SMA type I. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Solución numérica de procesos de transferencia de calor en aleaciones con condiciones de contorno no lineales

    Directory of Open Access Journals (Sweden)

    Alhama, F.

    2005-12-01

    Full Text Available Thermal properties of a great number of alloys, especially specific heat, show a sharply temperature dependence both during the phase change and the allotropic transformations. This fact, in conjunction with the existence of convection or radiation boundary conditions, or both simultaneously, increase the complexity of the transient heat transfer problem because of the inherent no linearity. The numerical model proposed for the solution of this problem is able to assume the above hypothesis as well as the temperature dependencies of the thermal conductivity. Applications to alloys are presented.

    Las propiedades térmicas de numerosas aleaciones, especialmente la capacidad calorífica, acusan una marcada dependencia con la temperatura tanto en los cambios de fase como en las transformaciones alotrópicas. Este hecho, junto con la aplicación de condiciones de contorno de convección, radiación o ambas, simultáneamente, aumentan la complejidad del problema de transferencia de calor en los procesos transitorios debido a la no linealidad inherente. El modelo numérico propuesto para la solución de este problema es capaz de asumir las hipótesis anteriores así como las posibles dependencias de la conductividad térmica con la temperatura. Se presentan aplicaciones a procesos térmicos en aleaciones.

  5. MODELADO DE DINÁMICA DE FLUIDOS Y TRANSFERENCIA DE CALOR Y MASA EN PROCESOS AGROALIMENTARIOS POR MÉTODO DE VOLÚMENES FINITOS

    Directory of Open Access Journals (Sweden)

    NELSON O. MORAGA

    2011-01-01

    Full Text Available Se describe la transferencia de momento, calor y masa transitorio bi-dimensional en procesos agroalimentarios. Estos procesos son: la pre-cosecha y la deshidratación por aire caliente de frutas. La metodología incluye modelación matemática y simulación computacional para describir la convección y difusión de calor y masa conjugada que resulta de la interacción entre el alimento y el aire. El modelo matemático emplea las ecuaciones diferenciales parciales no lineales acopladas de continuidad, momento lineal, energía y materia. Se considera que las propiedades físicas de las frutas calculadas mediante correlaciones empíricas, varían con la temperatura y la concentración de humedad. El método de volúmenes finitos junto el algoritmo SIMPLE se utiliza para obtener los resultados de la variación en el tiempo de las distribuciones de velocidades (v, temperaturas (T y concentraciones de humedad (C para los procesos en estudio. Las propiedades termofísicas variables de los alimentos se obtuvieron a partir de modelos empíricos. Los resultados obtenidos incluyen distribuciones de las variables dependientes (v, T, C en el tiempo, los cuales se comparan con resultados experimentales y numéricos de la literatura especializada.

  6. Computational program to design heat pumps by compression (ciclo 1.0); Programa computacional para diseno de bombas de calor por compresion (ciclo 1.0)

    Energy Technology Data Exchange (ETDEWEB)

    De Alba Rosano, Mauricio [CIE, UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    A new computational program has been developed in order to design single stage compression heat pumps. This software, named CICLO 1.0 allows the design of water-water, water-air, air-water and air-air heat pumps, for industrial and residential applications. CICLO 1.0 simulates three types of compressors: reciprocating, screw and scroll. Also has a data base created with REFPROP software which includes eleven refrigerants. The condenser and evaporator simulation includes global conductance (UA) determination, and when one or both are shell and tube's type, this software shows the even number of tube passes by shell. The software determines the best compressor and refrigerant setup taking the COP as a parameter; in order to obtain this, is necessary to know the inlet/outlet conditions of the fluid to be heated, the inlet conditions of the fluid that gives heat, and the electric motor efficiency that drives the compressor. The afforded results by CICLO 1.0 are: operation conditions from compression cycle, that means, pressures and temperatures at the inlet/outlet from every heat pump component are determined: as well as refrigerant mass flux, COP, power required by compressor, volumetric and isentropic efficiencies, heat exchangers global conductance and more data. CICLO 1.0 has been executed with heat pump data that nowadays are operating, and the results from the simulation have been very similar each other with data reported from operational facilities. [Spanish] Se ha desarrollado un nuevo programa computacional para el diseno de bombas de calor por compresion de vapor de una sola etapa. Este programa, CICLO 1.0, permite el diseno de bombas de calor de tipo: agua-agua, agua-aire, aire-agua y aire-aire, que se utilicen para aplicaciones industriales, de servicios y residenciales. CICLO 1.0 simula tres tipos de compresores: reciprocante, de tornillo y scroll: cuenta con una base de datos de refrigerantes creada con el programa REFPROP la cual incluye once

  7. Efectos fisiológicos de la deshidratación. ¿Por qué los deportistas deben ingerir líquidos durante el ejercicio en el calor?

    OpenAIRE

    González-Alonso, José; F. Coyle, Edward

    1998-01-01

    Durante el ejercicio prolongado realizado en condiciones de calor ambiental, los deportistas incurren en niveles de deshidratación bastante acusados debido principalmente a las grandes pérdidas de agua a través del sudor (1-2 l/h). Datos recientes demuestran que esta deshidratación progresiva causa alteraciones significativas de los sistemas cardiovascular, metabólico, termorregulador y endocrino, que a su vez pueden anticipar la aparición de la fatiga, ocasionar un golpe de calor o incluso c...

  8. Exposure to a highly caloric palatable diet during pregestational and gestational periods affects hypothalamic and hippocampal endocannabinoid levels at birth and induces adiposity and anxiety-like behaviors in male rat offspring

    Directory of Open Access Journals (Sweden)

    Maria Teresa eRamírez-López

    2016-01-01

    Full Text Available Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and, although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory and emotions.

  9. Concepciones alternativas de los docentes en formación del Instituto Pedagógico Superior Juan Demóstenes Arosemena sobre los conceptos de energía, calor y temperatura

    Directory of Open Access Journals (Sweden)

    Rodríguez, Viterbo

    2012-09-01

    Full Text Available Resumen: El artículo presenta los resultados de una investigación realizada en el año 2009 en el Instituto Pedagógico Superior Juan Demóstenes Arosemena. La metodología utilizada en el estudio es del tipo descriptiva cuantitativa y se utilizó una prueba de elección múltiple para recoger los datos. Cada ítem de la prueba centraba la atención en las concepciones alternativas sobre energía, calor y temperatura. Dicha prueba, después de su validación y pilotaje, fue desarrollada por 241 estudiantes de licenciatura de este Instituto. Luego de analizar las respuestas de los ítems, se obtuvo suficiente evidencia para concluir, significativamente, que los docentes en formación tienen concepciones alternativas: el 63.8% sobre el concepto de energía; 69% sobre el concepto de calor, y el 70.7% sobre el concepto de temperatura y movimiento (p=0.05. Las respuestas proporcionadas por los estudiantes demuestran que un elevado número considera que las transformaciones de energía ocurren sin ningún tipo de intercambio ni degradación de la misma. Esto revela su falta de comprensión de las leyes de la termodinámica. Las concepciones alternativas sobre el concepto de energía sugieren tres áreas o líneas principales de problemas: el concepto mismo de energía, los procesos que implican la transferencia de energía y el principio de conservación de la energía.Abstract: This article presents the results of research conducted in 2009 in the Instituto Pedagógico Superior Juan Demóstenes Arosemena. The methodology used in the study is descriptive research with a predominantly quantitative approach. A test was used with multiple-choice questions to collect data. Each item of the test was focused on alternative conceptions about energy, heat and temperature. The test, after validation and Piloting, was solved by 241 undergraduate students from the teaching training programs at Instituto Pedagógico. After analyzing the answers of the items, we

  10. Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, Hernando; Sanchez, I.; Lazcano, L. C.; Ambriz, Juan Jose; Alvarez, M. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O. [Comision Federal de Electricidad, Tula (Mexico)

    1996-12-31

    The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

  11. Playing Music May Improve the Gait Pattern in Patients with Bilateral Caloric Areflexia Wearing a Cochlear Implant: Results from a Pilot Study

    Directory of Open Access Journals (Sweden)

    Ann Hallemans

    2017-08-01

    Full Text Available HypothesisAuditory information through an active cochlear implant (CI influences gait parameters in adults with bilateral caloric areflexia and profound sensorineural hearing loss.BackgroundPatients with bilateral caloric areflexia suffer from imbalance, resulting in an increased risk of falling. In case of simultaneous deafness, the lack of auditory feedback results in less awareness of the auditory scene. This combination might produce significant challenges while walking and navigating. Auditory cues can be restored to some extent with a CI. Electrical stimulation through a CI can also produce a vestibulocollic reflex through current spread, which can be measured as cervical vestibular-evoked myogenic potentials.MethodsAdults (seven males, one female, mean age 61 ± 14 years, wearing a CI to treat profound sensorineural hearing loss and presenting with bilateral caloric areflexia walked barefoot, over ground, at self-selected speed in three different conditions: with CI turned on, while listening to music and with CI turned off. Spatiotemporal and kinematic parameters of gait were calculated using the conventional gait model.ResultsRemoving auditory feedback by turning off the CI decreased stride time (mean difference 0.03 ± 0.15 s and slightly increased stride length (mean difference 0.5 ± 1.2 cm compared to the control condition with the CI on. Walking while playing music positively affected gait compared to walking with the CI on but without auditory feedback. By increasing the motion of the pelvis (mean difference 1.3° ± 0.4°, the knee (mean difference 3.9° ± 0.8° and the ankle (mean difference 2.2° ± 0.2°, stride length increased (7.8 ± 1.2 cm, while stride time decreased (0.059 ± 0.016 s.ConclusionAlthough a practice effect cannot be completely ruled out, this pilot study suggests that playing music while wearing an active CI may improve gait in patients with bilateral otovestibular

  12. Desenvolvimento e avaliação de calorímetros por nitrogênio líquido e fluxo contínuo para medição de aporte térmico Development and assessment of calorimeters using liquid nitrogen and continuous flow (water for heat input measurement

    Directory of Open Access Journals (Sweden)

    Hernán Dario Hernández Arevalo

    2012-09-01

    Full Text Available Um dos parâmetros mais influentes no processo de soldagem a nível industrial e de pesquisa é o calor entregue à chapa (aporte térmico devido a sua direta ligação com a mudança das características metalúrgicas e propriedades mecânicas da junta soldada. Para o estudo e quantificação do calor aportado na peça de trabalho, tem-se utilizado tanto métodos teóricos (analíticos e numéricos, quanto experimentais (calorimetria. Estas técnicas apresentam ampla dispersão dos resultados obtidos para o rendimento térmico. Desta forma, a proposta deste trabalho é apresentar o projeto, construção e avaliação de um calorímetro de nitrogênio líquido e fluxo contínuo (água para a medição do aporte térmico e rendimento térmico de processos GTAW e GMAW. Para o processo GTAW, cordões sobre chapa foram realizados com Ar puro e chapas de aço ao carbono ASTM A36 e variou-se os parâmetros de soldagem como corrente, comprimento do arco, velocidade de soldagem e comprimento do cordão de solda. Foram também realizadas soldagens sobre chapa com o processo GMAW em transferência por curto-circuito e goticular (spray, onde o arame utilizado foi AWS ER70S-6 (1,2 mm de diâmetroe gás de proteção Ar+25%CO2 (curto-circuito e Ar+5%O2 (goticular. Para os processos derivativos (STT - Surface Tension Transfer, RMD - Regulated Metal Deposition, CMT - Cold Metal Transfer, GMAW-P - Pulsado e GMAW-PV - Polaridade Variável foram tomados como base parâmetro de soldagem encontrados por outros autores no Laprosolda (Centro para Pesquisa e Desenvolvimento de Processos de Soldagem. De modo geral, o calorímetro de nitrogênio líquido apresentou boa repetibilidade com diferença máxima de 3%. Também foi observado que durante os testes realizados no calorímetro de nitrogênio liquido apresentaram resultados coerentes para as diferentes condições de soldagem e reportando valores de rendimento térmico global de 70,3% para o processo GTAW, 78

  13. Diseño, Construcción y Calibración de un calorímetro de solución de precisión media

    Directory of Open Access Journals (Sweden)

    Alfredo Gómez O.

    2009-07-01

    Full Text Available Se descriten los criterios de diseño, la construcción y la calibración de un calorímetro isoperit> ólico de solución de precisión media y de bajo costo. Se miden los cambios térmicos mediante un termistor de 15.000 otimios a 293 K, cuya calibración permite encontrar la expresión AT = -52,495 log,o (Rf/Ri para el cambio de temperatura en función de la resistencia, en el rango de trabajo, 297 a 299 K, La sensibilidad termométríca es 0,00158 K/otimio. El error relativo máximo en las medidas calorimétricas con el sistema de calibración benceno-cíclotiexano es de 3%. el de la capacidad calorífica es de 2,74% y el correspondiente a la diferencia de temperatura es de 1,66%, Se encuentran problemas por la gran pendiente de pérdidas de calor, 0,048 K/mln. (valor máximo observado. El coeficiente de transferencia de calor de las paredes del vaso calorimétrico resultó elevado aunque cumple las especificaciones exigidas.

  14. Heat transfer coefficients obtainment by means of naphthalene sublimation in air; Obtencion de coeficientes de transferencia de calor por medio de la tecnica de sublimacion de naftalina en aire

    Energy Technology Data Exchange (ETDEWEB)

    Perez Galindo, Jose Arturo; Garcia Gutierrez, Alonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    This work describes the experimental technique for the sublimation of naphthalene in air which measures heat transfer coefficients through the use of the analogy between the transference phenomena of heat and mass. The technique used to substitute the experimental measurements of heat transfer, in which it is difficult to control the border thermal conditions, when they are dimmed by the omnipresent problem of heat conduction through the walls of the transference surfaces. Two examples are included of the application technique and its potential is outlined. [Espanol] En este trabajo se describe la tecnica experimental de la sublimacion de naftalina en aire mediante la que se miden coeficientes de transferencia de masa. Los datos asi obtenidos pueden convertirse en coeficientes de transferencia de calor a traves del uso de la analogia entre los fenomenos de transferencia de calor y masa. La tecnica se utiliza para substituir las mediciones experimentales de transferencia de calor, en las que es dificil controlar las condiciones termicas de frontera, cuando las empana el problema omnipresente de la conduccion de calor a traves de las paredes de las superficies de transferencia. Se incluyen dos ejemplos de la aplicacion de la tecnica y se destaca su potencial.

  15. Análise de viabilidade técnico-econômica de sistemas solares combinados a bombas de calor para aquecimento de água

    OpenAIRE

    Gonçalves, Juliana Emanuella

    2016-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2016. Uma análise da viabilidade técnico-econômica de sistemas solares com-binados a bombas de calor para aquecimento de água é conduzida neste trabalho com o objetivo de estimular o uso de energia solar térmica no Brasil. Duas configurações distintas são propostas: (1) sistema solar com dois reservatórios conectados em série e uma bomba de c...

  16. Influência da idade e do estresse cíclico de calor no perfil bioquímico sérico em frangos de corte

    Directory of Open Access Journals (Sweden)

    João Paulo Rodrigues Bueno

    2017-06-01

    Full Text Available Objetivou-se avaliar a influência da idade e do estresse cíclico por calor durante uma hora por dia, nas concentrações das proteínas, metabólitos e enzimas séricas em frangos de corte de 21 a 42 dias de idade. Foram utilizados 420 pintos de corte machos, da linhagem Cobb Avian48TM, em um delineamento inteiramente casualizado, composto de dois tratamentos e seis repetições. Os tratamentos foram constituídos de dois ambientes térmicos: um para frangos de corte criados em condições naturais de temperatura e umidade do primeiro ao 42° dia de idade (controle; e outro para estressados por calor à 36 °C do 16° ao 42° dia, durante uma hora do dia (12h00m às 13h00m. No 21º, 28º, 35º e 42º dias de idade, foram coletados em duas aves por repetição aproximadamente 5mL de sangue por punção cardíaca. Foram determinadas em cada amostra de soro as concentrações de proteína total, albumina, globulinas, relação A/G, aspartato aminotransferase, alanina aminotransferase, gama glutamiltransferase, ácido úrico, creatinina, colesterol total, triacilgliceróis, lipoproteínas de alta densidade, lipoproteínas de muito baixa densidade, lipoproteínas de baixa densidade e glicose. Para as concentrações de glicose, ácido úrico, alanina aminotransferase, triacilgliceróis e lipoproteínas de muito baixa densidade, não houve diferenças significativas para ambiente e idade. Observou-se interação significativa entre ambiente e idade para os valores de colesterol e lipoproteínas de baixa densidade. Aos 21 dias de idade o colesterol e as LDL-C foram maiores nas aves em estresse comparados àquelas do tratamento controle, o que não ocorreu nas demais idades. A aspartato aminotransferase nos frangos sob estresse cíclico de calor foi maior em comparação ao tratamento controle e apresentou efeito cúbico para ambiente. A idade das aves influenciou os valores de proteínas totais, albumina, globulina, albumina: globulina, creatinina

  17. Diseño óptimo de un disipador de calor para luminaria LED mediante moderación modelación computacional

    Directory of Open Access Journals (Sweden)

    Daniel Cahue Díaz

    2014-01-01

    Full Text Available En el presente trabajo se desarrolla una selección de materiales y simulación térmica en el diseño de disipadores de calor para sistemas de iluminación de estado sólido (SSL mejor conocidos como luminarias LEDs. Se desarrolló un modelo matemático con la capacidad de predecir el comportamiento térmico de la luminaria cuando se encuentra en operación. El modelo matemático fue resuelto mediante un software de distribución libre el cual permite resolver ecuaciones diferenciales mediante el método de elemento finito. Los resultados obtenidos en el modelo matemático planteado fueron validados con los resultados obtenidos mediante experimentación usando imágenes termográficas.

  18. Desenvolvimento de um simulador com interface amigável de um módulo didático de transferência de calor em aletas

    Directory of Open Access Journals (Sweden)

    Welington Pereira Santos

    2001-05-01

    Full Text Available Neste trabalho, foi implementado um simulador com interface amigável de um módulo didático clássico de transferência de calor em aletas, utilizado em várias instituições de ensino superior. O simulador foi desenvolvido em linguagem orientada a objetos DELPHI e apresenta um formulário de entrada de dados interativo em uma janela, enquanto o resultado da simulação é visualizado na forma gráfica. O simulador possui um banco de correlações de literatura para a estimação das propriedades físicas e dos parâmetros térmicos do modelo

  19. Estudo da transferência de calor em fluidos não-newtonianos em dutos circulares e não-circulares

    OpenAIRE

    Conceição, Wagner André dos Santos

    2002-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Alimentos. Sistemas de trocas térmicas são de grande importância na indústria de alimentos. O objetivo principal deste trabalho é fazer uma revisão de correlações para transferência de calor em fluidos não-newtonianos em dutos circulares e não-circulares, que são apresentadas em artigos, e ainda não foram divulgadas adequadamente, e também propor modificações em ...

  20. COMPARAÇÃO ENTRE TÉCNICAS NUMÉRICAS PARA A RESOLUÇÃO DO PROBLEMA DE TRANSFERÊNCIA DE CALOR EM ALIMENTOS ENLATADOS

    OpenAIRE

    A. D. Rodrigues; SCHMIDT F.L.; VITALI,A.A.; TEIXEIRA NETO,R.O.; TEIXEIRA,A.A.; S.P.M. GERMER; SADAHIRA,M.S.

    1998-01-01

    Este trabalho apresenta a comparação das técnicas de resolução numérica de Diferenças Finitas e Runge-Kutta-Gill de 4a ordem com passo de integração variável para a simulação do modelo de transferência de calor em regime transiente bidimensional em coordenadas cilíndricas e unidimensional em coordenadas esféricas, aplicado a alimentos enlatados processados em autoclave, observando-se a rapidez e a precisão de integração comparados aos perfis reais de tempo/temperatura, incluindo desvios de pr...

  1. Análisis de la máxima intensidad de la isla de calor urbana nocturna de la ciudad de Rancagua (Chile y sus factores explicativos.

    Directory of Open Access Journals (Sweden)

    Pablo Sarricolea

    2008-12-01

    Full Text Available Las ciudades constituyen el hábitat por excelencia de los seres humanos, y pese a su diversidad presentan características ambientales (clima urbano comunes en muchas partes del mundo, como por ejemplo la presencia de la Isla de Calor Urbana (ICU, que corresponde a un aumento de origen antrópico de las temperaturas de la ciudad en comparación con su entorno inmediato de carácter natural y rural, siendo más intensa dicha diferencia en las noches. Por ello, el propósito de esta investigación es analizar la Máxima Intensidad de la Isla de Calor Urbana (MIICU de Rancagua a partir de mediciones de las temperaturas con transectos móviles y estaciones meteorológicas fijas. Se ha determinado que la máxima intensidad de la isla de calor urbana de Rancagua bordea los 6°C en verano y primavera, y 3°C para invierno y otoño. Los factores que explican las distribuciones de las temperaturas urbanas de Rancagua corresponden a las distancias a fuentes húmedas (río Cachapoal y las densidades poblacionales; y en menor medida las características topográficas del emplazamiento de la ciudad y las áreas verdes urbanas medidas a partir del índice normalizado de diferencias vegetales (NDVI. La principal conclusión de esta investigación indica que la ausencia de parques urbanos en Rancagua explica la distribución de las temperaturas y la elevada intensidad de la isla de calor, y también la no significativa relación entre temperaturas y NDVI. De no revertirse esta situación, la sostenibilidad ambiental futura de la ciudad de Rancagua se verá muy amenazada por el crecimiento urbano.Cities are the environment for excellence in human beings, and despite their diversity, environmental features (urban climate are common in many parts of the world, such as the presence of the Urban Heat Island (UHI. This corresponds to a temperature increase due to human activities in the city compared with its immediate natural and rural surroundings, the difference

  2. REDUCCIÓN DE LA CANTIDAD DE Vibrio mimicus CON CALOR O ÁCIDO ACÉTICO EN HUEVO DE TORTUGA (Lepidochelys olivacea)

    OpenAIRE

    M\\u00F3nica Pereira-Zamora; Eric Wong-Gonz\\u00E1lez

    2010-01-01

    Este estudio se realizó en el Ce ntro Na cional de Cie ncia y Tecnología de Alimentos en el año 2000, con el fin de determinar la reducción de Vibrio mimicus en huevo de tortuga lora utilizando calor o ácido acético. Para ellos se determinó el tiempo de coagulación a diferentes temperaturas o niveles de pH con el fin de seleccionar los que podían utilizarse para la reducción del patógeno sin afectar las cualidades sensoriales del huevo crudo. Los huevos inoculados con Vibrio mimicus con carga...

  3. Protein-pacing caloric-restriction enhances body composition similarly in obese men and women during weight loss and sustains efficacy during long-term weight maintenance

    DEFF Research Database (Denmark)

    Arciero, Paul J; Edmonds, Rohan; He, Feng

    2016-01-01

    /day) in obese adults. Less is known whether obese men and women respond similarly to P-CR during weight loss (WL) and whether a modified P-CR (mP-CR) is more efficacious than a HH diet during long-term (52 week) weight maintenance (WM). The purposes of this study were to evaluate the efficacy of: (1) P......) completed WM. mP-CR regained significantly less body weight (6%), TBF (12%), and ABF (17%) compared to HH (p weight loss, body composition and biomarkers, and maintains these changes for 52-weeks compared to a traditional HH diet.......Short-Term protein-pacing (P; ~6 meals/day, >30% protein/day) and caloric restriction (CR, ~25% energy deficit) improves total (TBF), abdominal (ABF) and visceral (VAT) fat loss, energy expenditure, and biomarkers compared to heart healthy (HH) recommendations (3 meals/day, 15% protein...

  4. Software para la enseñanza de la dinámica y control de intercambiadores de calor de tubos y coraza

    Directory of Open Access Journals (Sweden)

    Fiderman Machuca

    2008-01-01

    Full Text Available Este trabajo presenta la estructura de un software desarrollado para la enseñanza y aprendizaje de la dinámica y control de intercambiadores de calor de tubos y coraza. El programa presenta, de manera numérica y gráfica, el comportamiento dinámico en lazo abierto y cerrado del proceso para diferentes parámetros de diseño y condiciones de operación variables. El software permite modificar condiciones tanto de operación como de diseño, por ejemplo, temperatura y caudales de entrada a los tubos y coraza, número y longitud de tubos, número de pasos, diámetro externo e interno de los tubos, diámetro interno de coraza y factor de ensuciamiento.

  5. Less-than-expected weight loss in normal-weight women undergoing caloric restriction and exercise is accompanied by preservation of fat-free mass and metabolic adaptations.

    Science.gov (United States)

    Koehler, K; De Souza, M J; Williams, N I

    2017-03-01

    Normal-weight women frequently restrict their caloric intake and exercise, but little is known about the effects on body weight, body composition and metabolic adaptations in this population. We conducted a secondary analysis of data from a randomized controlled trial in sedentary normal-weight women. Women were assigned to a severe energy deficit (SEV: -1062±80 kcal per day; n=9), a moderate energy deficit (MOD: -633±71 kcal per day; n=7) or energy balance (BAL; n=9) while exercising five times per week for 3 months. Outcome variables included changes in body weight, body composition, resting metabolic rate (RMR) and metabolic hormones associated with energy conservation. Weight loss occurred in SEV (-3.7±0.9 kg, Pweight loss was significantly less than predicted (SEV: -11.1±1.0 kg; MOD: -6.5±1.1 kg; both P0.33). RMR decreased by -6±2% in MOD (P=0.020). In SEV, RMR did not change on a group level (P=0.66), but participants whose RMR declined lost more weight (P=0.020) and had a higher baseline RMR (P=0.026) than those whose RMR did not decrease. Characteristic changes in leptin (P=0.003), tri-iodothyronine (P=0.013), insulin-like growth factor-1 (P=0.016) and ghrelin (P=0.049) occurred only in SEV. The energy deficit and adaptive changes in RMR explained 54% of the observed weight loss. In normal-weight women, caloric restriction and exercise resulted in less-than-predicted weight loss. In contrast to previous literature, weight loss consisted almost exclusively of fat mass, whereas fat-free mass was preserved.

  6. Areal and volumetric bone mineral density and geometry at two levels of protein intake during caloric restriction: a randomized, controlled trial.

    Science.gov (United States)

    Sukumar, Deeptha; Ambia-Sobhan, Hasina; Zurfluh, Robert; Schlussel, Yvette; Stahl, Theodore J; Gordon, Chris L; Shapses, Sue A

    2011-06-01

    Weight reduction induces bone loss by several factors, and the effect of higher protein (HP) intake during caloric restriction on bone mineral density (BMD) is not known. Previous study designs examining the longer-term effects of HP diets have not controlled for total calcium intake between groups and have not examined the relationship between bone and endocrine changes. In this randomized, controlled study, we examined how BMD (areal and volumetric), turnover markers, and hormones [insulin-like growth factor 1 (IGF-1), IGF-binding protein 3 (IGFBP-3), 25-hydroxyvitamin D, parathyroid hormone (PTH), and estradiol] respond to caloric restriction during a 1-year trial using two levels of protein intake. Forty-seven postmenopausal women (58.0 ± 4.4 years; body mass index of 32.1 ± 4.6 kg/m(2) ) completed the 1-year weight-loss trial and were on a higher (HP, 24%, n = 26) or normal protein (NP, 18%, n = 21) and fat intake (28%) with controlled calcium intake of 1.2 g/d. After 1 year, subjects lost 7.0% ± 4.5% of body weight, and protein intake was 86 and 60 g/d in the HP and NP groups, respectively. HP compared with NP diet attenuated loss of BMD at the ultradistal radius, lumbar spine, and total hip and trabecular volumetric BMD and bone mineral content of the tibia. This is consistent with the higher final values of IGF-1 and IGFBP-3 and lower bone-resorption marker (deoxypyridinoline) in the HP group than in the NP group (p bone loss at certain sites in postmenopausal women. Copyright © 2011 American Society for Bone and Mineral Research.

  7. Intragastric pH and pressure profiles after intake of the high-caloric, high-fat meal as used for food effect studies.

    Science.gov (United States)

    Koziolek, M; Schneider, F; Grimm, M; Modeβ, Chr; Seekamp, A; Roustom, T; Siegmund, W; Weitschies, W

    2015-12-28

    The intraluminal conditions of the fed stomach are critical for drug release from solid oral dosage forms and thus, often associated with the occurrence of food effects on oral bioavailability. In this study, intragastric pH and pressure profiles present after the ingestion of the high-caloric, high-fat (964 kcal) FDA standard breakfast were investigated in 19 healthy human subjects by using the telemetric SmartPill® capsule system (26 × 13 mm). Since the gastric emptying of such large non-digestible objects is typically accomplished by the migrating motor complex phase III activity, the time required for recurrence of fasted state motility determined the gastric emptying time (GET). Following the diet recommendations of the FDA guidance on food effect studies, the mean GET of the telemetric motility capsule was 15.3 ± 4.7 h. Thus, the high caloric value of the standard breakfast impeded gastric emptying before lunch in 18 out of 19 subjects. During its gastric transit, the capsule was exposed to highly dynamic conditions in terms of pH and pressure, which were mainly dependent on further meal and liquid intake, as well as the intragastric capsule deposition behavior. Maximum pH values in the stomach were measured immediately after capsule intake. The median pH value of the 5 min period after capsule ingestion ranged between pH 3.3 and 5.3. Subsequently, the pH decreased relatively constantly and reached minimum values of pH 0-1 after approximately 4 h. The maximum pressure within the stomach amounted to 293 ± 109 mbar and was clearly higher than the maximum pressure measured at the ileocaecal junction (60 ± 35 mbar). The physiological data on the intraluminal conditions within the fed stomach generated in this study will hopefully contribute to a better understanding of food effects on oral drug product performance.

  8. Method to allow the estimation of heat transfer coefficients in solar stills; Metodo para determinar coeficientes locales de transferencia de calor en destiladores solares

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Cerda, Eduardo; Porta Gandara, Miguel A [CIBNOR, Mexico D.F (Mexico); Fernandez Zayas, Jose Luis [UNAM Mexico, D.F. (Mexico)

    2000-07-01

    This work reports an experimental method that allows to estimate the heat transfer coefficients in the neighborhood of walls or flat plates subject to convective transport phenomena. This method can be applied to a great variety of thermal systems since it is based on the knowledge of the border condition for the temperature at the surface of the plate, and the temperature profile that characterize the dimensionless coefficient of heat transfer in the fluid, according to its definition given by the Nusselt number. The approach of this work are the foundations of the method and the system that has been developed to apply it, that incorporates automatic acquisition equipment for continuos monitoring of the information and elements to control the parameters of interest. In addition, the experimental cavities on which the method will be evaluated are discussed, considering two different scales, as well as experiments in cavities filled with air, and with a mixture of air and steam water, as is the case for solar distillation. [Spanish] En este trabajo se presenta un metodo que permite determinar de manera experimental coeficientes de transferencia de calor por conveccion. Este metodo puede ser aplicado a una gran variedad de sistemas termicos ya que se fundamenta en el conocimiento de la condicion de frontera para la temperatura en la superficie de la placa, y del perfil de temperaturas que caracteriza el coeficiente adimensional de transferencia de calor en el fluido, de acuerdo a la definicion de este, dada por el numero de Nusselt. El trabajo que aqui se reporta esta enfocado a la fundamentacion del metodo y al equipamiento que se ha desarrollado para instrumentarlo, que incorpora equipos automaticos de adquisicion continua de informacion y elementos de control para los parametros de interes. Se presentan ademas, las cavidades experimentales sobre las que sera evaluado el metodo, que considera dos escalas diferentes, asi como experimentos en cavidades llenas de aire

  9. Composição centesimal e valor calórico de alimentos de origem animal Proximate food composition and caloric value of foods from animal origen

    Directory of Open Access Journals (Sweden)

    Elizabeth A.F.S TORRES

    2000-08-01

    Full Text Available Dados sobre composição de alimentos são importantes para inúmeras atividades, porém são escassos ou inexistentes em nosso país. O presente trabalho teve como objetivo determinar o valor calórico dos alimentos de origem animal comumente usados na dieta: carne, leite e ovos a fim de compará-los com os dados das tabelas de composição centesimal mais utilizadas por profissionais da área. Observou-se que de um modo geral, ocorrem variações entre os valores das tabelas consultadas e os analisados, sendo estes menores para ovos, seguidos de laticínios, carnes suínas, carnes bovinas e aves. Salientamos portanto, a importãncia de obtenção dados sobre a composição de alimentos condizentes com diferenças regionais do Brasil, visto que a maioria das tabelas disponíveis são compilações de dados internacionais.Proximate food composition data are very important to any professionals of food science and human nutrition area. In Brazil they are rare or do not exist. The food composition of items, of animal origin, usually consumed in the diet: meat, milk e eggs, were analyzed in order to determine their caloric value. After that they were compared with the data in the Tables of Food Composition (TFC commonly used to our professionals. It was observed that there are smaller differences in the values obtained for eggs, than milk, pork, beef, chicken. Although significant difference was not detected between determined caloric values and the ones from TFC, these report should be considered to professionals that use the TFC.

  10. CONCEPCIONES ALTERNATIVAS SOBRE LOS CONCEPTOS DE ENERGÍA, CALOR Y TEMPERATURA DE LOS DOCENTES EN FORMACION DEL INSTITUTO PEDAGÓGICO EN SANTIAGO, PANAMÁ

    Directory of Open Access Journals (Sweden)

    Viterbo Rodríguez

    2012-01-01

    Full Text Available El artículo presenta los resultados de una investigación realizada en el año 2009 en el Instituto Pedagógico Superior Juan Demóstenes Arosemena. La metodología utilizada en el estudio es del tipo descriptiva cuantitativa y se utilizó una prueba de elección múltiple para recoger los datos. Cada ítem de la prueba centraba la atención en las concepciones alternativas sobre energía, calor y temperatura. Dicha prueba, después de su validación y pilotaje, fue desarrollada por 241 estudiantes de licenciatura de este Instituto. Luego de analizar las respuestas de los ítems, se obtuvo suficiente evidencia para concluir, significativamente, que los docentes en formación tienen concepciones alternativas: el 63.8% sobre el concepto de energía; 69% sobre el concepto de calor, y el 70.7% sobre el concepto de temperatura y movimiento (p=0.05. Las respuestas proporcionadas por los estudiantes demuestran que un elevado número considera que las transformaciones de energía ocurren sin ningún tipo de intercambio ni degradación de la misma. Esto revela su falta de comprensión de las leyes de la termodinámica. Las concepciones alternativas sobre el concepto de energía sugieren tres áreas o líneas principales de problemas: el concepto mismo de energía, los procesos que implican la transferencia de energía y el principio de conservación de la energía.

  11. Thermal and friction drop characteristic of heat exchangers with elliptical tubes and smooth fins//Caracterización térmica e hidráulica de intercambiadores de calor con tubos elípticos y aletas lisas

    Directory of Open Access Journals (Sweden)

    Rubén Borrajo-Pérez

    2012-09-01

    Full Text Available Pressure drop and heat transfer are the most important parameters in compact heat exchanger. There is a lack of information in the literature about heat exchanger with elliptical tube. The objective of this work was the experimental characterization of compact heat exchangers models using elliptical tube with eccentricity of 0,5 and smooth fins. The Reynolds numbers and the spacing were varied and always inside laminar regime. The experiments were conducted in an open wind tunnel using sublimation of naphthalene and the heat and mass transfer analogy. As results, the average and local Nusselt number and friction factor for 36 models were obtained. Correlations for Colburn and friction factors were presented. This correlations were obtained for 200calor son importantes parámetros en intercambiadores de calor. Existe falta de información cuando de intercambiadores de calor y tubos elípticos se trata. El objetivo del trabajo fue caracterizar experimentalmente modelos de intercambiadores de calor con tubos elípticos yaletas lisas. El numero de Reynolds y los espaciamientos fueron variados, dentro del régimen laminar. Los experimentos fueron desarrollados en un túnel de viento de circuito abierto usando la sublimación de naftaleno y la analogía calor y masa. Los números de Nusselt medio, locales y el factor de fricción fueronobtenidos en forma de correlaciones de Factores de Fricción y Colburn. Las correlaciones, validas para 200

  12. Modelación y simulación de disipadores de calor para procesadores de computadora en COMSOL Multiphysics Modeling and simulation of heat sinks for computer processors in COMSOL Multiphysics

    Directory of Open Access Journals (Sweden)

    Sulin Garro Acón

    2012-11-01

    Full Text Available En este estudio se analizó la transferencia de calor en tres disipadores de calor utilizados para enfriar los procesadores de computadoras de escritorio. El objetivo de estos disipadores es evitar el sobrecalentamiento de la unidad de procesamiento y la consecuente reducción de la vida útil del computador. Los disipadores de calor se modelaron usando COMSOL Multiphysics con las dimensiones reales de los dispositivos y la generación de calor se modeló con una fuente puntual. Luego se modificaron los diseños de los disipadores para lograr una temperatura más baja en la zona más caliente del procesador. El resultado fue una reducción en la temperatura en el rango de 5-78 grados Kelvin, al rediseñarse el disipador de calor con variaciones feasibles como la reducción del grosor de las placas de intercambio de calor y el aumento de su número. Esto demuestra la posibilidad de desarrollar diseños optimizados para disipadores de calor que no requieran más materiales sino una mejor ingeniería. El trabajo se inició como parte del curso CM-4101 Modelización y Simulación.In this study, the heat transfer of three desktop- computer heat sinks was analyzed. The objective of using these heat sinks is to avoid overheating of the computer’s processing unit and in turn reduce the corresponding loss in the unit’s service time. The heat sinks were modeled using COMSOL Multiphysics with the actual dimensions of the devices, and heat generation was modeled with a point source. In the next step, the heat sink designs were modified to achieve a lower temperature in the higher temperature location on the heat sink. The results were temperature reductions in the range of 5-78 degrees Kelvin, by making feasible variations in design such as reducing the thickness of the heat exchanger fins and increasing their number. This paper demonstrates that there is room to develop improved designs that do not require more materials but rather a better engineering

  13. Efficiency tests on the pyrolysis gasifier stove Peko Pe

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts

    1996-01-01

    This paper presents results from water boiling tests on the pyrolysis gasifier stove Peko Pe, which has been developed by the Norwegian Paal Wendelbo. The stove efficiency determined vary between 21 and 29% when burning dry Danish woodchips (10% moisture) with an estimated caloric value of 16 MJ...... the water content in the grass. In Adjumani refugee camp it was furthermore found that the stove was able to provide sufficient energy from solid combustion, after the pyrolysis was stopped, to boil water for additional 25-30 minutes with lid. This effect was not seen in the tests on woodchips in Denmark...

  14. Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy

    2002-01-01

    ...) to support her development as a breast cancer researcher, and to conduct a study to test whether a program of moderate aerobic exercise that is combined with a moderate level of dietary restriction...

  15. Effects of Moderate Aerobic Exercise Combined with Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy

    2003-01-01

    ... in the reduction of the risk of breast cancer by testing whether moderate aerobic exercise can reduce the levels of two hormonal biomarkers, circulating estrogens and insulin-like growth factor I (IGF...

  16. Modelación de la transferencia de calor y masa en el absorbedor de una máquina de refrigeración por absorción. Resultados para un banco de tubos. // Heat and mass transference modeling in the absorbent of an absorbator cooling machine.( Results for a bank

    OpenAIRE

    C. A. Cisneros Ramírez

    2002-01-01

    En este artículo se presenta el comportamiento de la temperatura, la concentración y el coeficiente de traspaso de calor,tanto local como promedio, durante el proceso de absorción sobre un banco de tubos. Además se presenta la ecuaciónobtenida a partir del modelo presentado en artículos anteriores, que caracteriza el comportamiento del producto delcoeficiente global de traspaso de calor (U) por el área de traspaso de calor (A) para el banco de tubos.Palabras claves: Modelación, absorbedores, ...

  17. Relevance of vestibulospinal tests after unilateral neurolabyrinthitis

    Directory of Open Access Journals (Sweden)

    Babić Borivoj B.

    2003-01-01

    Full Text Available In this paper we wanted to assess clinical relevance of two vestibulospinal tests: standing test (derived from Romberg test and past pointing test. In retrospective and prospective study 42 patients have been tested with standing test and 50 patients with past pointing test. All patients suffered from unilateral neurolabyrinthitis that had started from one day to two years prior to examination. All patients had unilateral areflexion, or hyporeflexion on caloric test using 10°C water. Control group consisted of 32 healthy individuals for both tests. Results show that both tests correctly indicate side of the lesion but only during first week of illness. Moreover, even during that first week sensitivity of both tests was below 50 %, which means that more then half results from patients fall within normal findings. We conclude that vestibulospinal tests do not deserve prominent place in assessing patients with vestibular syndrom. Conclusions must be made according to findings obtained from much more precise vestibuloocular tests.

  18. NÍVEL DE PROTEÇÃO TÉRMICA DA CASCA DE QUATRO ESPÉCIES LENHOSAS E A RELAÇÃO DA ARQUITETURA DA CASCA COM A TRANSFERÊNCIA DE CALOR

    Directory of Open Access Journals (Sweden)

    Ailton Teixeira do Vale

    2014-12-01

    Full Text Available A casca é um tecido protetor do câmbio e a exposição a temperaturas acima de 60°C durante 1 a 2 minutos é um dos principais fatores que causam a mortalidade de árvores em incêndios florestais. Neste trabalho foi estudado o nível de proteção da casca, como isolante térmico, de três espécies do cerrado: Pterodon pubescens, Vochysia thyrsoidea e Sclerolobium paniculatum e do Eucalyptus grandis e a influência da arquitetura da casca na transferência de calor. Foram retiradas amostras na forma de painéis da casca de cinco árvores de cada espécie. Determinou-se o tempo necessário para que a temperatura no câmbio alcançasse 60ºC (temperatura letal e o coeficiente de rugosidade (arquitetura pela relação entre a área real e a área nominal da amostra. O Sclerolobium paniculatum, com menor espessura de casca, possui o menor tempo de resistência ao calor e o Eucalyptus grandis e o Pterodon pubescens os maiores tempos de resistência ao calor. A exceção foi a gomeira que com a maior espessura de casca possui um dos menores tempos de resistência ao calor. A espécie com maior correlação entre o tempo de resistência ao calor e a espessura de casca total foi o Sclerolobium paniculatum (r = 0,93. O Pterodon pubescens e o Eucalyptus grandis possuem r = 0,73 e r = 0,56, respectivamente, e a gomeira possui um baixo coeficiente de correlação (r = 0,34. A rugosidade da gomeira foi maior e diferiu significativamente das demais. No entanto, o coeficiente de correlação entre o tempo e a rugosidade não foi significativo para todas as espécies, sugerindo que o aumento da rugosidade não influenciou a transferência de calor através da casca.

  19. Análise da distribuição de focos de calor no município de Novo Progresso, Pará

    Directory of Open Access Journals (Sweden)

    Andréia Caroline Lima Lopes

    2017-06-01

    Full Text Available Os incêndios são um dos principais causadores de danos aos ecossistemas florestais. Existem diversas formas de detecção dos focos de calor. Entretanto, para países com grande extensão territorial como o Brasil, é mais eficiente e barato o monitoramento por imagens de satélite. A partir disso, objetivou-se analisar a distribuição de focos de calor no município de Novo Progresso, Pará no período de 2010 a 2015, por meio de dados do monitoramento realizado por satélites de referência pertencentes ao Instituto Nacional de Pesquisas Espaciais. Após a organização das informações obtidas através do Banco de Dados de Queimadas, foram feitas análises dos fatores socioeconômicos e ambientais que intensificam o surgimento de focos de incêndios com o auxílio da literatura científica. Observou-se que os focos se concentraram na região nordeste do munícipio, ao longo da BR-163, apresentando maior ocorrência nos meses de agosto e setembro, o que pode estar relacionado com o período de estiagem do município. Analysis of the Distribution of hotspots in the Novo Progresso Town, Pará, BrazilAbstract: Fires are a major cause of damage to forest ecosystems. There are several ways of detecting hotspots. However, for countries with a vast territory as Brazil, the monitoring by satellite images is more efficient and cheaper. The aim of this study was to analyze the distribution of hotspots in the county of Novo Progresso, Pará, from 2010 to 2015 through data monitoring performed by reference satellites of the National Institute for Space Research. After organizing the information obtained through the Hotspots Database, analyses of socioeconomic and environmental factors that enhance the appearance of fire outbreaks were made with the assistance of scientific literature. It was observed that the outbreaks are concentrated in the northeastern area of the county along the BR-163, presenting higher occurrence in August and September, which

  20. Short-term trajectories of use of a caloric-monitoring mobile phone app among patients with type 2 diabetes mellitus in a primary care setting.

    Science.gov (United States)

    Goh, Glenn; Tan, Ngiap Chuan; Malhotra, Rahul; Padmanabhan, Uma; Barbier, Sylvaine; Allen, John Carson; Østbye, Truls

    2015-02-03

    Self-management plays an important role in maintaining good control of diabetes mellitus, and mobile phone interventions have been shown to improve such self-management. The Health Promotion Board of Singapore has created a caloric-monitoring mobile health app, the "interactive Diet and Activity Tracker" (iDAT). The objective was to identify and describe short-term (8-week) trajectories of use of the iDAT app among patients with type 2 diabetes mellitus in a primary care setting in Singapore, and identify patient characteristics associated with each trajectory. A total of 84 patients with type 2 diabetes mellitus from a public primary care clinic in Singapore who had not previously used the iDAT app were enrolled. The app was demonstrated and patients' weekly use of the app was monitored over 8 weeks. Weekly use was defined as any record in terms of food entry or exercise workout entry in that week. Information on demographics, diet and exercise motivation, diabetes self-efficacy (Diabetes Empowerment Scale-Short Form), and clinical variables (body mass index, blood pressure, and glycosylated hemoglobin/HbA1c) were collected at baseline. iDAT app use trajectories were delineated using latent-class growth modeling (LCGM). Association of patient characteristics with the trajectories was ascertained using logistic regression analysis. Three iDAT app use trajectories were observed: Minimal Users (66 out of 84 patients, 78.6%, with either no iDAT use at all or use only in the first 2 weeks), Intermittent-Waning Users (10 out of 84 patients, 11.9%, with occasional weekly use mainly in the first 4 weeks), and Consistent Users (8 out of 84 patients, 9.5%, with weekly use throughout all or most of the 8 weeks). The adjusted odds ratio of being a Consistent User, relative to a Minimal User, was significantly higher for females (OR 19.55, 95% CI 1.78-215.42) and for those with higher exercise motivation scores at baseline (OR 4.89, 95% CI 1.80-13.28). The adjusted odds ratio

  1. Effects of Moderate Aerobic Exercise Combined With Caloric Restriction on Circulating Estrogens and IGF-I in Premenopausal Women

    National Research Council Canada - National Science Library

    Williams, Nancy

    2002-01-01

    ... cancer, circulating estrogens and IGF-I. We will also test whether this type of diet/exercise program will produce significant reductions in the peripheral production of estrone by adipose tissue through its impact on the reduction of fat mass...

  2. Estudi comparatiu entre un sistema de climatització solar amb planta d’absorció geotèrmica i un sistema de climatització amb bomba de calor geotèrmica

    OpenAIRE

    Costillo Javier, Sergi

    2009-01-01

    Disseny i dimensionat d’una instal•lació de climatització, durant tot l'any, i comparació entre un sistema de climatització solar amb una planta d’absorció geotèrmica i un sistema de climatització mitjançant una bomba de calor geotèrmica, per al despatx de professors i becaris del nou laboratori d’ energia de l’EPS, mitjançant la utilització d’un sistema d’energia solar tèrmica de baixa temperatura, com a medi d’aportació de calor, i per energia geotèrmica per a la climatització integral...

  3. Início da tuberização, duração do ciclo vegetativo e tolerância ao calor em genótipos de batata

    OpenAIRE

    Lyra, Danilo Hottis; Ribeiro, Guilherme Henrique Martins Rodrigues; Figueiredo, Izabel Cristina Rodrigues de; Guedes, Marcio Lisboa; Carneiro, Otávio Luiz Gomes; Pinto, César Augusto Brasil Pereira; Pereira, Arione da Silva

    2015-01-01

    Resumo: O objetivo deste trabalho foi avaliar a relação do tempo para o início da tuberização e da duração do ciclo vegetativo com a tolerância ao calor em batata. Grupos de clones com diferentes tempos para o início de tuberização e durações do ciclo vegetativo foram definidos e avaliados em dois ambientes, e seus índices morfofisiológicos foram estimados em condições de estresse de calor. A amplitude para o início da tuberização foi de 31,8 dias e para a duração do ciclo vegetativo de 30,3 ...