University of Hawaii at Manoa

About: University of Hawaii at Manoa is a education organization based out in Honolulu, Hawaii, United States. It is known for research contribution in the topics: Population & Sea surface temperature. The organization has 13693 authors who have published 25161 publications receiving 1023924 citations.

Caloric restriction, the traditional Okinawan diet, and healthy aging: the diet of the world's longest-lived people and its potential impact on morbidity and life span.

Abstract: Long-term caloric restriction (CR) is a robust means of reducing age-related diseases and extending life span in multiple species, but the effects in humans are unknown. The low caloric intake, long life expectancy, and the high prevalence of centenarians in Okinawa have been used as an argument to support the CR hypothesis in humans. However, no long-term, epidemiologic analysis has been conducted on traditional dietary patterns, energy balance, and potential CR phenotypes for the specific cohort of Okinawans who are purported to have had a calorically restricted diet. Nor has this cohort's subsequent mortality experience been rigorously studied. Therefore, we investigated six decades of archived population data on the elderly cohort of Okinawans (aged 65-plus) for evidence of CR. Analyses included traditional diet composition, energy intake, energy expenditure, anthropometry, plasma DHEA, mortality from age-related diseases, and current survival patterns. Findings include low caloric intake and negative energy balance at younger ages, little weight gain with age, life-long low BMI, relatively high plasma DHEA levels at older ages, low risk for mortality from age-related diseases, and survival patterns consistent with extended mean and maximum life span. This study lends epidemiologic support for phenotypic benefits of CR in humans and is consistent with the well-known literature on animals with regard to CR phenotypes and healthy aging.

Interdecadal modulation of El Nino amplitude during the past millennium

Abstract: Our ability to predict El Nino/Southern Oscillation (ENSO) activity is hampered by the relatively short length of the instrumental record. An annually resolved record of ENSO variability over the past millennium based on tree rings indicates that ENSO amplitude varies on a 50–90 year cycle, providing an important constraint for improving predictions. The El Nino/Southern Oscillation (ENSO) is the dominant mode of interannual climate variability on Earth, alternating between anomalously warm (El Nino) and cold (La Nina) conditions in the tropical Pacific at intervals of 2–8 years1,2. The amplitude of ENSO variability affects the occurrence and predictability of climate extremes around the world3,4, but our ability to detect and predict changes in ENSO amplitude is limited by the fact that the instrumental record is too short to characterize its natural variability5,6,7,8. Here we use the North American Drought Atlas9,10—a database of drought reconstructions based on tree-ring records—to produce a continuous, annually resolved record of ENSO variability over the past 1,100 years. Our record is in broad agreement with independent, ENSO-sensitive proxy records in the Pacific and surrounding regions. Together, these records indicate that ENSO amplitude exhibits a quasi-regular cycle of 50–90 years that is closely coupled to the tropical Pacific mean state. Anomalously warm conditions in the eastern Pacific are associated with enhanced ENSO variability, consistent with model simulations11. The quasi-periodic ENSO amplitude modulation reported here offers a key observational constraint for improving models and their prediction of ENSO behaviour linked to global warming.

Design of regular (2,d/sub c/)-LDPC codes over GF(q) using their binary images

Abstract: In this paper, a method to design regular (2, dc)- LDPC codes over GF(q) with both good waterfall and error floor properties is presented, based on the algebraic properties of their binary image. First, the algebraic properties of rows of the parity check matrix H associated with a code are characterized and optimized to improve the waterfall. Then the algebraic properties of cycles and stopping sets associated with the underlying Tanner graph are studied and linked to the global binary minimum distance of the code. Finally, simulations are presented to illustrate the excellent performance of the designed codes.

Adding Biofuels to the Invasive Species Fire

Abstract: Biofuel crops, particularly using non-native species, must be introduced with an understanding of possible risks to the environment.

Development of the ALOHANET

Abstract: The development of the ALOHA system packet broadcasting network at the University of Hawaii illustrates a number of general principles about the relationship between information theory and the design of real information systems. An anecdotal account is given of the development of the ALOHA system, emphasizing the interaction of the theory and the design of the experimental network. In addition, some preliminary results are described on the comparison of ALOHA channels and spread spectrum channels when used for packet communications.