Quantifying health utilities of young adult orthodontic patients using the time trade-off method: a cross-sectional study

ABSTRACT Objective: To study the feasibility of time trade-off (TTO) method in quantifying health utility ratings in different types of malocclusion. Material and Methods: In this cross-sectional study, 70 orthodontic patients aged 18 years or above, reporting for treatment/consultation, were included and interviewed. Malocclusion-related health utilities were assessed through the TTO method, and oral health-related quality of life was measured with the help of Orthognathic Quality of Life Questionnaire (OQLQ). Angle's classification of malocclusion was recorded. Bivariate analyses and multivariate Poisson's regression were done to find out an association between the oral health utility values, OQLQ and demographic and clinical characteristics. Results: Patients with skeletal Class III malocclusion had lower health utility values than those with Class I and Class II malocclusions (p=0.013). Poisson's regression showed that Angle's Class II division 1 (0.90, CI 0.84 to 0.97), Class III (0.68, CI 0.59 to 0.95) and Skeletal malocclusion (0.79, CI 0.71 to 0.87) and OQLQ scores (1.0, CI 1 to 1.003) were found to be significant predictors of TTO utility scores. Conclusions: TTO utilities were found to be valid and well correlated with clinical findings. Health utilities could serve as useful and reliable markers of health-related quality of life (HRQL) among individuals or communities and help cost-effective preventive or intervention programs planning.

RESUMO Objetivo: Estudar a viabilidade do método Time trade-off (TTO) para quantificar escores de valoração da saúde em diferentes tipos de má oclusão. Material e Métodos: Neste estudo transversal, foram incluídos e entrevistados 70 pacientes ortodônticos com idade igual ou superior a 18 anos, que compareceram para tratamento/consulta. A valoração da saúde em relação à má oclusão foi avaliada por meio do método TTO e a qualidade de vida relacionada à saúde bucal foi medida com a ajuda do Questionário de Qualidade de Vida Ortognática (Orthognathic Quality of Life Questionnaire, OQLQ). A classificação da má oclusão segundo Angle foi registrada, e análises bivariadas e regressão multivariada de Poisson foram feitas para verificar qualquer associação entre os escores de valoração da saúde bucal, OQLQ e características demográficas e clínicas. Resultados: Os pacientes com má oclusão esquelética de Classe III apresentaram escores de valoração da saúde mais baixos do que aqueles com má oclusão de Classe I e Classe II (p=0,013). A regressão de Poisson mostrou que a Classe II de Angle divisão 1 (0,90, IC 0,84 a 0,97), Classe III (0,68, IC 0,59 a 0,95), má oclusão esquelética (0,79, IC 0,71 a 0,87) e os escores do OQLQ (1,0, IC 1 a 1,003) foram considerados preditores significativos dos escores de valoração pelo método TTO. Conclusões: Os escores do TTO foram considerados válidos e bem correlacionados com os achados clínicos, e podem servir como marcadores úteis e confiáveis da qualidade de vida relacionada à saúde (health-related quality of life, HRQL) entre indivíduos ou comunidades, e ajudar no planejamento de programas de prevenção ou de intervenção, com uma boa relação custo-benefício.

Aspirin for primary prevention: Is this the end of the road?

Aspirin is one of the oldest and most commonly used cardiovascular drugs. Despite there being high-quality evidence supporting the use of aspirin for patients with known cardiovascular disease, a definitive consensus regarding its use for patients at risk for cardiovascular disease (and without established cardiovascular disease) has never been reached. Many randomized control trials have produced conflicting results, and consequently, society guidelines have issued differring recommendations. Three major trials were published in 2018, which supplement the existing data on aspirin's role in primary prevention and provide further guidance on this contentious issue. This article reviews the history of aspirin through the last two decades, with special emphasis on these new trials.

Disability Weights for Osteoporosis and Osteoporotic Fractures in South Korea

BACKGROUND: Korea is expected to become an ultra-aged society, in which the elderly population will account for more than 20% of the total population, after 2025. Thus, the social costs due to osteoporotic fractures are expected to increase. Therefore, this study aimed to measure disability weights (DWs) of osteoporosis and osteoporotic fractures in Korea. METHODS: The scenarios were developed to standardize the severity of 6 health statuses: osteoporosis and osteoporotic fractures including wrist, hip, post-hip, vertebral, and post-vertebral fracture. The values for these 6 health statuses were sought via a person trade-off (PTO) approach. We measured the value by PTO and we calculated it to DW of 6 health statuses. Three clinical expertise panels of 33 experts were established, and face-to-face interviews were conducted from July to December 2017. RESULTS: The distribution of DW varied by panel. DWs ranged from 0.5 (Osteoporosis) to 0.857 (Hip fracture) for Panel 1, 0.091 (Osteoporosis) to 0.5 (Hip fracture) for Panel 2, and 0.091 (Osteoporosis) to 0.726 (Hip fracture) for Panel 3. The final values for the 6 health statuses obtained by pooling all data from 3 panels ranged from 0.286 (Osteoporosis) to 0.750 (Hip fracture). There was no significant difference in rankings for the 6 health statuses among the 3 panels. CONCLUSIONS: Comparing the DW of osteoporotic fracture in this study with other diseases in previous studies, it is predicted that osteoporotic fractures, especially hip fractures, will have a considerable burden of disease.

Biomass allocation and nutrients balance related to the concentration of Nitrogen and Phosphorus in Salvinia auriculata (Salviniaceae) / Alocação de biomassa e o Balanço de nutrientes relacionados à concentração de Nitrogênio e Fósforo em Salvinia auriculata (Salviniaceae)

Abstract Aquatic plants can use differential allocation (trade-off) of carbon among their structures depending on the nutrition concentration. Given that N and P are limiting in the growth of plants, our questions were: Are the N and P concentrations in S. auriculata related to the biomass allocation to its structures? Is a differential allocation of N and P between floating and submerged leaves? We evaluated the relation between the nutrients and the biomass allocation, and the trade-off among the leaves using the Spearman correlation. Our results showed that N and P concentrations in S. auriculata are related to the biomass allocation to its structures, and that there is no trade-off of these nutrients between “shoot and root”. Thus, we can see the importance of N and P concentration in the biomass of S. auriculata, and why this plant is capable to development in different environments as a weedy.

Resumo Plantas aquáticas podem realizar alocação diferencial (trade-off) de carbono entre as suas estruturas dependo da disponibilidade de nutrientes. Considerando que N e P são limitantes para o crescimento de plantas, nossas perguntas foram: As concentrações de N e P em S. auriculata estão relacionadas com a alocação de biomassa para suas estruturas? Existe alocação diferencial de N e P entre os folíolos aéreos e a “raiz”? Avaliamos a relação entre os nutrientes e a biomassa, e o trade-off entre as folhas utilizando correlação de Spearman. Os resultados encontrados mostram que as concentrações de N e P em S. auriculata estão relacionadas com a alocação de biomassa para as suas estruturas, e que não há um trade-off de N e P entre os folíolos aéreos e a “raiz”. Dessa maneira, é possível observar a importância de N e P no ganho de biomassa de S. auriculata, e porque a espécie é capaz de se desenvolver em diferentes ambientes como uma planta daninha.

Resource allocation in Copaifera langsdorffii (Fabaceae): how supra-annual fruiting affects plant traits and herbivory?

AbstractPlants have limited resources to invest in reproduction, vegetative growth and defense against herbivorous. Trade-off in resources allocation promotes changes in plant traits that may affect higher trophic levels. In this study, we evaluated the trade-off effect between years of high and low fruiting on the investment of resources for growth and defense, and their indirect effects on herbivory in Copaifera langsdorffii. Our questions were: (i) does the resource investment on reproduction causes a depletion in vegetative growth as predicted by the Carbon/Nutrient Balance hypothesis (CNBH), resulting in more availability of resources to be allocated for defense?, (ii) does the variation in resource allocation for growth and defense between years of high and low fruiting leads to indirect changes in herbivory? Thirty-five trees located in a Cerrado area were monitored during 2008 (year of high fruiting) and 2009 (year of no fruiting) to evaluate the differential investment in vegetative traits (biomass, growth and number of ramifications), plant defense (tannin concentration and plant hypersensitivity) and herbivory (galling attack and folivory). According to our first question, we observed that in the fruiting year, woody biomass negatively affected tannin concentration, indicating that fruit production restricted the resources that could be invested both in growth as in defense. In the same way, we observed an inter-annual variation in herbivorous attack, and found that plants with higher leaf biomass and tannin concentration, experienced higher galling attack and hypersensitive reaction, regardless years. These findings suggested that plants’ resistance to herbivory is a good proxy of plant defense and an effective defense strategy for C. langsdorffii, besides the evidence of indirect responses of the third trophic level, as postulated by the second question. In summary, the supra-annual fruiting pattern promoted several changes on plant development, demonstrating the importance of evaluating different plant traits when characterizing the vegetative investment. As expected by theory, the trade-off in resource allocation favored changes in defense compounds production and patterns of herbivory. The understanding of this important element of insect-plant interactions will be fundamental to decipher coevolutionary life histories and interactions between plant species reproduction and herbivory. Besides that, only through long-term studies we will be able to build models and develop more accurate forecasts about the factors that trigger the bottom-up effect on herbivory performance, as well the top-down effect of herbivores on plant trait evolution. Rev. Biol. Trop. 64 (2): 507-520. Epub 2016 June 01.

ResumenLas plantas tienen recursos limitados para invertir en reproducción, crecimiento vegetativo y defensa contra herbívoros. El cambio en la distribución de recursos promueve variaciones en rasgos vegetales, que pueden afectar los niveles tróficos superiores. Durante dos años consecutivos de alta y baja inversión reproductiva se evaluó el cambio de recursos entre crecimiento vegetativo y defensa, y su efecto indirecto sobre la herbivoría en Copaifera langsdorffii. Nos preguntamos: i) ¿La inversión de recursos para la reproducción causa reducción del crecimiento vegetativo, como predice la hipótesis de equilibrio carbono/nutrientes, haciendo posible gastar más recursos en defensa? ii) ¿La variación en distribución de recursos para crecimiento y defensa entre años de alta y baja fructificación modifica indirectamente la herbivoría? Se monitorearon treinta y cinco árboles durante 2008 (gran fructificación) y 2009 (sin fructificación) en un área de vegetación de cerrado (Brasil), para evaluar la inversión diferencial en rasgos vegetativos (biomasa, crecimiento y No. de ramificaciones), defensa (concentración de taninos e hipersensibilidad vegetal) y herbivoría. De acuerdo a nuestra primera pregunta, se observó que en el año de fructificación la biomasa leñosa afectó negativamente la concentración de taninos, indicando que la producción de frutos redujo los recursos que podían invertirse en crecimiento y defensa. Además, la resistencia de las plantas y el ataque de agallas fueron influidos positivamente por la concentración de taninos y la biomasa foliar, lo que sugiere que la resistencia de los árboles a la herbivoría es un buen indicador de defensa vegetal y una estrategia efectiva de defensa de C. langsdorffii, además hay evidencia de respuesta trófica indirecta, como se postula en la segunda pregunta. En resumen, el patrón de fructificación supra-anual provoca varios efectos en el desarrollo de las plantas, mostrando la importancia de evaluar diversos rasgos vegetales al caracterizar la inversión de recursos de una especie. Como se esperaba, el cambio en la distribución de recursos modifica la producción de compuestos de defensa y los patrones de herbivoría. El entendimiento de este elemento importante de las interacciones insecto-planta será fundamental para descifrar la historia natural coevolutiva y las interacciones entre reproducción vegetal y ataque herbívoro. Además de eso, solo a través de estudios a largo plazo vamos a ser capaces de construir modelos y desarrollar pronósticos más precisos acerca de los factores que desencadenan el efecto de abajo hacia arriba en el rendimiento de la herbivoría, así el efecto de arriba hacia abajo de los herbívoros sobre la evolución de las plantas.

Reproductive strategy of Copaifera langsdorffii (Fabaceae): more seeds or better seeds?

The trade-off seed size/number is a recognized phenomenon capable of shaping ecological processes of colonization and establishment of plant species. Studies that describe trade-offs size/number of seeds in supra-annual fruiting species are still rare. In this study, two predictions for trade-off size/number hypothesis were tested: (i) on a population scale, seeds produced during years of greater reproductive investment showed reduced size, and (ii) on individual scale there is an inverse relationship between size and number of seeds produced by individual plant. To test these predictions, 102 Copaifera langsdorffii adult plants were monitored monthly from January to September during four consecutive years (2008 to 2011) in order to study the reproductive investment of plants. C. langsdorffii plants exhibited reproductive activity only during years 2008 and 2011. The mean number of seeds per branch was 26.4 % greater in 2008 comparatively to 2011. It was also observed that seed size was greater in the year of 2008, when plants produced greater number of fruits. Thus, the data did not support the first prediction of seed size/number hypothesis. In both reproductive years, there was a negative relationship between seed size and number of seeds, supporting the second prediction of the seed size/number hypothesis. The interaction term with the reproductive year suggests that the trade-off size/number of seeds was indeed stronger in 2011, when the plants produced lower seed number. Finally, this study calls the attention to supra-annual fruiting pattern in C. langsdoffii, and suggests that the phenological patterns contribute to explain the wide variation in their seed size and geographical distribution.

El compromiso o balance adaptativo de las semillas en tamaño/ número (trade-off seed size/number) es un reconocido fenómeno capaz de dar forma a los procesos ecológicos de la colonización y el establecimiento de especies de plantas. Los estudios que describen el compromiso adaptativo de las semillas en tamaño/número en especies con fructificación supra-anual siguen siendo raros. En este estudio, se probaron dos hipótesis predictivas para compromiso adap-tativo de las semillas en tamaño/número: (i) una a escala poblacional, semillas producidas durante el año de mayor inversión reproductiva mostraran un tamaño reducido, y (ii) otra a escala individual que se dará una relación inversa entre el tamaño y número de semillas producidas por la planta individual. Para probar estas predicciones, 102 plantas adultas de Copaifera langsdorffii fueron monitoreadas mensualmente entre enero y septiembre, durante cuatro años consecutivos (2008-2011) con el fin de estudiar la inversión reproductiva de las plantas. Plantas langsdorffii C. exhibieron actividad reproductiva sólo durante el 2008 y 2011. El número promedio de semillas por rama fue 26.4 % mayor en 2008 en comparación con 2011. También se observó que el tamaño de la semilla fue mayor en 2008, cuando las plantas producen mayor número de frutos. Por lo tanto, los datos no apoyan la primera hipótesis de predicción de tamaño/número. En ambos años reproductivos, existía una relación negativa entre el tamaño de la semilla y el número de semillas, comprobando la segunda hipótesis de predicción del tamaño/número de semillas. El periodo de interacción con el año reproductivo sugiere que el compromiso adaptativo de las semillas en tamaño/número fue de hecho más fuerte en 2011, cuando las plantas produjeron baja cantidad de semillas. Por último, este estudio llama la atención por el patrón de fructificación supra-anual en C. langsdoffii, y sugiere que los patrones fenológicos contribuyen a explicar la amplia variación en el tamaño de la semilla y la distribución geográfica.

Optimal Portfolio Construction With Nifty Stocks.

This paper endeavors to build an ideal portfolio by utilizing Sharpe‘s Single index model. For this reason, NSE NIFTY and all the 50 stocks where are a part of it have been utilized as business record for planning portfolio. The everyday information for all the stocks and list for the period of April 2008 to December 2013 has been gathered. The proposed model will define a special cut off point (Cut off rate of return) and chooses stocks having overabundance of their normal return over risk free rate of return surpassing this cut-off point. Rate of venture in each of chosen stocks is then settled on the support of separate weights allocated to each one stock relying upon individual beta value, stock development change unsystematic risk, return on stock and hazard free return versus the cut off rate of return. According to our findings, our optimal portfolio comprises of four stocks chose out of 50 shot recorded scripts, giving the reappearance of 0.116 %.

Reproductive traits and population structure of Astyanax aeneus (Characiformes: Characidae) from a subtropical river in Mexico / Rasgos reproductivos y estructura de la población de Astyanax aeneus (Characiformes: Characidae) de un río subtropical en México

Champotón River is an unknown area within the Mesoamerican hotspot in Southestern México. Reproductive traits and population structure of Astyanax aeneus were analyzed along an environmental gradient of the upper, middle and lower sections of the river, where diverse environmental factors were recorded. For this, nets were cast for 1h at each site and A. aeneus were collected from all sections with sweep nets (5 and 10m long by 5m deep, 0.03m mesh size) and a casting net (0.05m mesh size). At each study site and campaign, a total of 80 specimens (in average) were collected and were fixed in 10% formaldehyde for further analysis. Population structure by size was analyzed for each study site, based on the relative frequencies by standard length classes. The length-weight relationship was determined, and the identification of gonadal developmental stages, reproductive period, size at first sexual maturity, relative fecundity, sex ratio and somatic indexes (gonadosomatic, hepatosomatic and Fulton’s condition factor) were also assessed. Seven size classes were found in the upper and middle sections, and nine downstream, with seasonal and spatial pattern in size-class frequency distribution. Size at first maturity was 45.7mm for females and 40.8mm for males. The maximum relative fecundity was recorded at the downstream site and was positively correlated with body weight and standard length. Sex ratio (1.8:1 males: females) differed significantly from expected values (1:1). Gonadosomatic index scores indicated that the reproductive period of this species in the Champotón River was from April to July, during the warm and wet season. Hepatosomatic index was negatively correlated with the Gonadosomatic index, evidencing transfer of energy from the liver towards gamete production. This strategy enabled A. aeneus to maintain robustness during the study period with tiny changes in condition factor. A. aeneus in the Champotón River, as opposed to South American river congeneric species of similar size, shows early sexual maturity, a short reproductive period with high gonadosomatic index values, and high fecundity, a trade-off for the short reproductive period. Spatio-temporal segregation was evident: breeders congregate down- stream, while juveniles prefer the upper reaches. This pattern allows A. aenus to be successful in a river with high frequency of hurricanes.

El Río Champotón es un área de desconocimiento científico dentro del hotspot de Mesoamérica en el sureste de México. Las características reproductivas y la estructura de la población de Astyanax aeneus fueron analizadas a lo largo de un gradiente ambiental en la porción dulceacuícola del río. Se estudiaron tres sitios: en la parte alta del río San Juan Carpizo, en la porción media San Antonio del Río y río abajo en Ulumal, en cinco períodos entre 2007 y 2008. Se registraron diversos factores ambientales en cada sitio de estudio. Los ejemplares de A. aeneus se recolectaron con redes de arrastre de 5 y 10m de largo por 5m de profundidad (0.03m malla) y atarraya (con luz de malla de 0.05m). Las redes fueron lanzadas durante 1 hora en cada sitio. En cada visita se recolectaron un promedio de 80 especímenes en cada sitio de estudio que se preservaron en formaldehído al 10% para su posterior análisis. Para cada sitio de estudio se analizó la estructura de la población por talla, con base en las frecuencias relativas de las clases de longitud estándar. Se determinó la relación peso-talla, se identificaron las etapas del desarrollo gonadal, la época reproductiva, el tamaño de primera madurez sexual, la fecundidad absoluta y relativa, la proporción de sexos y los índices somáticos (gonadosomático, hepatosomático y el factor de condición de Fulton). Se obtuvieron siete clases de talla en la parte alta y media del río y nueve río abajo, con un patrón de distribución estacional y espacial en las frecuencias de clase de tallas. La talla de primera madurez fue de 45.7mm en hembras y 40.8mm en machos. La máxima fecundidad absoluta se registró río abajo y se correlacionó positivamente con el peso corporal y la longitud estándar. La proporción de sexos (1.8:1 machos: hembras) difiere significativamente de los valores esperados (1:1). Los resultados del índice gonadosomático (IGS) indican que el período reproductivo en el Río Champotón es en julio, durante la temporada húmeda y cálida. El índice hepatosomático se correlacionó negativamente con el IGS, evidenciando la transferencia de energía desde el hígado hacia la producción de gametos. Esta estrategia permitió que A. aeneus mantuviera una condición robusta durante el periodo de estudio con pequeños cambios en el factor de condición. Nuestros resultados indican que A. aeneus en el río Champotón, a diferencia de otras especies del mismo género y de la misma talla en ríos de Sudamérica, presenta una maduración sexual precoz, una temporada reproductiva corta con elevados valores del IGS, y una elevada fecundidad, lo que compensa la temporada de reproducción corta. También se percibe una tendencia a la segregación espacial y temporal: los reproductores se congregan aguas abajo y los juveniles prefieren las partes más altas. Este patrón permite a A. aeneus tener éxito en un río con una alta frecuencia de huracanes.

Quality of life after first- and second- eye cataract surgery on community project in Lombok Island, West Nusa Tenggara, Indonesia.

Background: This study aims to assess the quality of life and the time trade off-utility value of the first eye cataract surgery and the second eye cataract surgery in Lombok Island-Indonesia. Methods: This was an epidemiologic survey study on community of cataract surgery. Evaluations of quality of life (QoL) and time trade-off (TTO) were performed using questionnaire prior and three weeks after cataract surgeries who had either first (group A) or second eye cataract surgery (group B). Personal data was noted especially on self-care, mobility, socially, and mentally status. Data was analyzed by chi-square test for categorical data and unpaired t-test or Mann-Whitney test for numeric data. Results: A total of 77 subjects was included in this study, there were 50 subjects in group A and 27 subjects in group B. Elements of QoL were improved after surgeries including self care, mobility, social, and mental status in both groups (p < 0.001). The modified TTO was accepted in 35 subjects in group A and 22 subjects in group B. Quality of life was improved in 46 patients in group A, there was further improvement in 22 patients in group B. The degree of patient’s expectation was good in 87% of all subjects. Conclusion: Second- eye cataract surgery showed further improvement in QoL despite better outcome of the first- eye cataract surgery. The outcome of cataract surgery conducted was relevant to the patient’s expectation.

Assessment of vision-related quality of life in Chinese glaucoma patients by utility analysis / 中华实验眼科杂志

BackgroundThe influence of glaucoma on the quality of life in patients is of increasing concern for ophthalmologists in recent years. However,some studies demonstrated that different types of questionnaires about quality of life have various disadvantages. Therefore, to accurately and fully assess the influencing factors of quality of life in glaucoma patients is very important. ObjectiveThe present study was to survey the self-reported visionrelated quality of life(QOL) in glaucoma patients by means of utility analysis and to tentatively analyze its influencing factors. Methods Patients with glaucoma were recruited from a single tertiary ophthalmic department. Standard face-to-face interviews were conducted. Utility values of linear rating scale ( RS ) and time trade-off ( TTO ) were calculated to evaluate the self-reported vision-related QOL of the patients. The correlations of the utility values with the patients' general and ophthalmologic characteristics were also analyzed. This survey was approved by the Ethic Committee of Beijing Tongren Hospital. Oral informed consent was obtained from the subjects before the study.ResultsA cross-sectional study was designed. A total of 86 glaucoma patients were enrolled in this study with 62 male and 24 female, with a mean age of 44. 67 years old. The mean utility values measured by RS and TTO were 0. 62± 0. 19 and 0. 77 ± 0. 12, respectively, and no evidential correlation was found between these two values ( r =0. 074, P=0. 499 ). The RS value was associated with daily visual acuity,mean deviation(MD) of visual field and the history of trabeculectomy. Neither daily visual acuity nor MD showed a significant correlation with the TTO value. Age, work status and educational background contributed to higher utility value for the TTO method. After adjusting for age, work status and educational level,patients with visual acuity in the worse-seeing eye better than 0. 3 showed a higher TTO value than those with less than 0. 3. Conclusions Utility analysis possesses the advantages of convenience and sensitivity. RS utility value is easily affected by the Objective visual status and surgery history in glaucomatous patients,which reflects the subjective assessment of patients'visual quality. However, TTO value is primarily associated with age,work status and education level rather than visual function in glaucoma patients,which is therefore subjective assessment of the disease-related quality of life. These Results indicate that visual function impairment is not a determining factor for the QOL of glaucoma patients.

Life-history of the South American darter, Characidium pterostictum (Crenuchidae): evidence for small scale spatial variation in a piedmont stream

The present study compares the reproduction, condition and size of the small characiform fish, Characidium pterostictum, sampled at close sites differing in severity of flash flood effects. Data were obtained from seasonal samples in two sites situated 8 km apart in the same stream. In the upstream site, habitat is more severely affected by flash floods than in the downstream site, and this difference was hypothesized to produce differences in life history and individual reproduction trade-off patterns, as predicted by life-history theory. The results provided evidence for small-scale spatial variation in life-history and trade-off patterns within the studied population. At the most severely disturbed site, C. pterostictum displayed a trade-off pattern that favored reproductive life-span (e.g., larger size, higher and seasonally stable condition, larger mean size of mature females) over instantaneous reproductive output (lower gonadosomatic index), while the opposite pattern was observed in the less disturbed site. Because of the differences in disturbance effects between each sampling site, these results suggest that within-stream variability in the severity of hydrological disturbance can influence life-history patterns at small spatial scales. An implication of the results is that fish occupying areas that are hydrologically more variable within a stream are not necessarily at an energetic or reproductive disadvantage, but may be simply under environmental conditions that favor distinct patterns of energy allocation (or trade-offs) and population persistence, as predicted by life-history theory. Therefore, plasticity in life-history is expected to be common in stream fish populations that are widespread in a stream system with spatially variable or patchy habitat characteristics.

Este estudo compara a estrutura populacional e a reprodução do pequeno caraciforme, Characidium pterostictum, amostrado em locais sujeitos a diferentes efeitos de perturbações hidrológicas naturais (enxurradas). Os dados foram obtidos a partir de amostragens sazonais em dois trechos distando 8 km entre si, no mesmo riacho. No trecho a montante, o habitat é mais severamente afetado pelas enxurradas do que no trecho a jusante e, devido a esta diferença, testou-se a hipótese de que haveria contrastes em padrões de alocação de energia entre reprodução e sobrevivência individual, como previsto pela teoria de história de vida. No trecho a montante, C. pterostictum apresentou características que favorecem a longevidade reprodutiva (como maior tamanho, condição mais elevada e sazonalmente pouco variável, maior tamanho de fêmeas maduras) em relação ao desempenho reprodutivo instantâneo (menor índice gonadossomático). O padrão oposto foi observado no trecho a jusante. Devido às diferenças em termos de efeito de perturbação (enxurradas) em cada trecho, esses resultados sugerem que a variabilidade espacial de perturbações hidrológicas pode influenciar padrões de história de vida dentro de uma população. Outra implicação dos resultados, é que os peixes que ocupam locais hidrologicamente mais variáveis em um riacho não estão necessariamente em desvantagem energética ou reprodutiva, mas podem estar simplesmente sob condições ambientais que favorecem padrões distintos de alocação de energia e persistência da população. Dessa forma, pode-se esperar que a plasticidade de história de vida seja comum em populações de peixes que sejam amplamente distribuídas em um sistema de riachos com características de hábitat espacialmente variáveis ou em mosaico.

Altitudinal distribution and body resource allocation in a High Mountain social wasp (Hymenoptera: Vespidae)

Jame's rule proposes a direct relationship between body size and altitude. There are several studies about this rule; however, few studies analyze proportional changes in body parts along gradients. The morphological variation of Agelaia pallipes (Olivier) in five sites along an altitudinal gradient (2600-3380 m) in the Santuario de Iguaque, Colombia, were studied in order to test whether or not the species follows Jame's rule, and whether body parts follow a homogeneous variation. Body variation analysis was conducted through multivariate analysis of variance (MANOVA) and the relationship between altitude and each morphometric measurement was studied through regression analyses. The MANOVA indicated significant differences among sites. An increase in altitude leads to a reduction in body size, especially in hind femur length and head width. However, measurements linked to flight such as mesosoma height, mesoscutum width, and fore wing size showed a reverse tendency. Possibly all described changes are consequence of both reduction on food availability and lower atmospheric pressure. The low temperature of high areas may strongly limit foraging and thus food availability. Lower atmospheric pressure reduces flight potential and may result in an increase in size of both wings and flight muscles. This paper underscores the need to study in detail the changes in body proportions in species with wide distribution ranges in latitude and altitude.

A regra de Jame propõe uma relação direta entre o tamanho do corpo e a altitude. Muitos estudos são relacionados a essa regra; no entanto, poucos analisam as mudanças proporcionais em partes do corpo ao longo de gradientes. Foi estudada a variação morfológica em Agelaia pallipes (Olivier) em cinco faixas altitudinais (2600-3380 m), no Santuario de Iguaque (Colombia), com o objetivo de testar se a espécie segue a regra de Jame e se o tamanho de determinadas estruturas varia homogeneamente ao longo do gradiente. O efeito da altitude em estruturas foi testado com análise de variância multivariada (MANOVA), e a relação entre cada variável e altitude avaliada com análises de regressão. A MANOVA mostrou diferenças no tamanho das estruturas entre os locais. O aumento na altura conduz à redução no tamanho de corpo, especialmente no comprimento do fêmur traseiro e na largura da cabeça. No entanto, medidas de estruturas relacionadas ao vôo, tais como o comprimento do mesosoma, largura do mesoscutum, e ainda, tamanho da asa anterior, apresentam tendência inversa. É possível que todas as mudanças sejam conseqüência da redução de alimento e da diminuição da pressão atmosférica. A temperatura baixa das altitudes maiores pode limitar o forrageamento e, portanto, os recursos. A baixa pressão atmosférica torna o vôo mais difícil e pode resultar no aumento do tamanho das asas e dos músculos do vôo. Este trabalho enfatiza a necessidade de estudos relacionados a mudanças nas proporções corporais em espécie com amplas distribuições, latitudinal e altitudinal.

Patterns of investment of the reproductive strategy of two stream-dwelling Characidae

The reproductive strategy of two congeneric species (Astyanax janeiroensis - AJ and Astyanax hastatus - AH) was assessed, in order to address the costs imposed by different investment patterns, on four major life history characters: migratory behaviour, breeding time, fecundity and egg size. Altitudinal segregation of young and adult individuals plus data from the literature indicated that AJ is a migratory species, whereas AH is non migratory. Breeding season (BS) analysis revealed that AH was reproductively active year-round (12 months), whereas AJ breeds during 9 months. Brood costs (Ovarian Investment) were almost the same for both species (AJ - 364 oocytes / g and egg volume = 0.52 mm³; AH -702 oocytes / g and egg volume = 0.27 mm³). Reproductive costs (RC), considered as product of gamete production (OI) and gamete output (BS), were 1,703.7 for AJ and 2,274.0 for AH; thus RC is 25 percent higher in AH. It is concluded that the costs with OI (egg size and egg numbers) are equal for both species but as breeding season is larger for AH the overall strategy is 25 percent more expensive in AH. Thus, it is hypothesized that this 25 percent should be considered as the extra costs that AJ uses during migration and is compensated by its shorter breeding time (9 months versus 12 months of AH).

A estratégia reprodutiva de duas espécies congenéricas (Astyanax janeiroensis - AJ e Astyanax hastatus - AH) foi analisada a fim de se determinar os custos energéticos impostos por diferentes padrões de investimento em quatro dos principais caracteres da história de vida de peixes: comportamento migratório, estação reprodutiva, fecundidade e tamanho dos ovócitos. A segregação espacial dos indivíduos jovens e adultos associada a informações da literatura indicaram que AJ é uma espécie migratória enquanto AH não migra. A análise sobre a estação reprodutiva (ER) revelou que AH se reproduz ao longo de todo o ciclo anual (12 meses) enquanto AJ se reproduz durante 9 meses. Os custos com a desova (Investimento Ovariano - IO) foram similares nas duas espécies (AJ - 364 ovócitos/g e volume dos ovócitos = 0,52 mm³; AH - 702 ovócitos/g e volume dos ovócitos = 0,27 mm³). O custo da reprodução (CR), considerado como o produto da produção de gametas (IO) e o tempo de liberação dos gametas (ER), foram 1.703,7 para AJ e 2.274,0 para AH; assim CR é 25 por cento superior em AH. Concluímos assim, que os custos com IO (tamanho e número de ovócitos) são iguais para as duas espécies, mas como a estação reprodutiva é maior para AH, a estratégia como um todo é mais custosa para AH. Dessa forma, sugerimos que os 25 por cento excedentes podem ser considerados como os custos extras que AJ necessita para a migração e são compensados pelo menor tempo da estação reprodutiva (9 meses em AJ versus 12 meses em AH).

A Conjoint-Based Approach to Analyze the Importance of Brand Choice Attributes: Pizza Restaurant Cases / 대한지역사회영양학회지

The purposes of this study were (1) to understand how customers trade off one attribute against another when they choose a pizza restaurant, (2) to compare the importance of individual attributes with their relative importance and (3) to compare customers' brand choice patterns with the prediction of pizza restaurant operators. Empirical data for this study were collected from the customers (n = 307) and operators (n = 273) of four famous pizza franchise restaurants in Korea, Pizza Hut, Mister Pizza, Domino's Pizza and Pizza Mall. The attributes and attribute levels for the hypothetical profiles were decided from the focus group discussion. A total of 16 profiles was selected from fractional factorial designs. The SPSS conjoint procedure was used to calculate utility scores and simulate profiles. The overall group statistics showed the relative importance of all attributes compared with one other. Taste was the most important attribute (32.48%) in choosing a pizza restaurant, followed by service (21.87%), atmosphere (17.23%), price (15.17%) and speed of delivery (13.26%). There was a difference between the customers' ratings of the importance of the individual attributes and the ranking of the same attributes' relative importance as derived from the conjoint analysis. The operators rated service (26.54%) as also being important, as well as taste (27.76%), in choosing a pizza restaurant. The rankings of relative importance for pizza taste, service and price were statistically different in the customers' and operators' data (p < .001, p < .01, p < .05). Operators who want to differentiate themselves from their competitors should make decisions based on an increased understanding of their customers' brand choice decision process and measure the hidden needs of their customers.