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.

Friends of hot jupiters. i. a radial velocity search for massive, long-period companions to close-in gas giant planets

Abstract: In this paper we search for distant massive companions to known transiting hot Jupiters that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 hot Jupiters obtained using the Keck HIRES instrument, and use these observations to search for long-term radial velocity accelerations. We find new, statistically significant accelerations in seven systems, including: HAT-P-10, HAT-P-20, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 AO imaging data to place constraints on the allowed masses and orbital periods of the companions. The estimated masses of the companions range between 1-500 M_(Jup), with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the short-period hot Jupiters in these systems, making them candidates for influencing the orbital evolution of the inner hot Jupiters. They also appear to occur preferentially in systems with more metal-rich host stars, and with typical orbital separations that are larger than those of multi-planet systems without hot Jupiters. We estimate a total occurrence rate of 55% +11% / -10% for companions with masses between 1-13 M_(Jup) and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions in hot Jupiter systems with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the hot Jupiters included in our survey.

Leadership for Learning: Does Collaborative Leadership Make a Difference in School Improvement?

Abstract: Although there has been a sizable growth spurt in empirical studies of shared leadership over the past decade, the bulk of this research has been descriptive. Relatively few published studies have investigated the impact of shared leadership on school improvement, and even fewer have studied effects on student learning. This longitudinal study examines the effects of collaborative leadership on school improvement and student reading achievement in 192 elementary schools in one state in the USA over a 4-year period. Using latent change analysis, the research found significant direct effects of collaborative leadership on change in the schools' academic capacity and indirect effects on rates of growth in student reading achievement. In addition, the study identified three different growth trajectories among schools, each characterized by variations in associated school improve- ment processes. The study supports a perspective on leadership for learning that aims at building the academic capacity of schools as a means of improving student learning outcomes.

A molecular role for lysyl oxidase in breast cancer invasion.

Abstract: We identified previously an up-regulation in lysyl oxidase (LOX) expression,an extracellular matrix remodeling enzyme, in a highly invasive/metastatic human breast cancer cell line, MDA-MB-231, compared with MCF-7, a poorly invasive/nonmetastatic breast cancer cell line. In this study, we demonstrate that the mRNA expression of LOX and other LOX family members [lysyl oxidase-like (LOXL), LOXL2, LOXL3, and LOXL4] was observed only in breast cancer cells with a highly invasive/metastatic phenotype but not in poorly invasive/nonmetastatic breast cancer cells. LOX and LOXL2 showed the strongest association with invasive potential in both highly invasive/metastatic breast cancer cell lines tested (MDA-MB-231 and Hs578T). To determine whether LOX is directly involved in breast cancer invasion, LOX antisense oligonucleotides were transfected into MDA-MB-231 and Hs578T cells, and found to inhibit invasion through a collagen IV/laminin/gelatin matrix in vitro compared with LOX sense oligonucleotide-treated and untreated controls. In addition, treatment of MDA-MB-231 and Hs578T cells with beta-aminopropionitrile (an irreversible inhibitor of LOX enzymatic activity) decreased invasive activity. Conversely, MCF-7 cells transfected with the murine LOX gene demonstrated a 2-fold increase in invasiveness that was reversible by the addition of beta-aminopropionitrile in a dose-dependent manner. In addition, endogenous LOX mRNA expression was induced when MCF-7 cells were cultured in the presence of fibroblast conditioned medium or conditioned matrix, suggesting a role for stromal fibroblasts in LOX regulation in breast cancer cells. Moreover, the correlation of LOX up-regulation and invasive/metastatic potential was additionally demonstrated in rat prostatic tumor cell lines, and human cutaneous and uveal melanoma cell lines. These results provide substantial new evidence that LOX is involved in cancer cell invasion.

Partner Selection and Venturing Success: The Case of Joint Ventures with Firms in the People's Republic of China

Abstract: It has been hypothesized in the international joint venture IJV literature that partner selection affects interpartner “fit” which in turn influences a synergistic effect on IJV performance. This study investigates the relationship between IJV success and the strategic and organizational traits of local partners. We address this issue in the context of an emerging economy P.R. China. Newly emerging economies have in recent years become major hosts of direct investment by multinational corporations MNCs because these rapidly expanding economies, characterized by an exploding demand previously stifled by ideologically-based government intervention, provide tremendous opportunities which MNCs can preempt. MNCs in such economies, however, face the challenges of structural reform, weak market structure, poorly specified property rights, and institutional uncertainty. Right local partners can help MNCs boost market expansion, obtain insightful information, mitigate operational risks, and provide country-specific knowledge. The analysis of the data obtained from China suggests that both strategic and organizational traits of local partners are significantly associated with some individual dimensions of IJV performance. Among strategic traits, absorptive capacity, product relatedness, and market power are favorable to IJVs' market and financial outcomes. Market power and experience significantly reduce IJVs' operational uncertainties. Of organizational traits, international experience and organizational collaboration are important for IJVs' not only profitability and stability but also local market expansion and export growth. Organizational form and size influence IJVs' local market performance. The findings provided by this study can help MNCs determine what criteria they should use in opting for local partners and what criteria are vital to their goal accomplishment. Those investors seeking local market expansion should select those local partners that have rich market experience, superior market position, high absorptive capacity, and related product diversification with the IJVs. Those seeking profitability and stability should select local firms that have superior international experience, longer organizational collaboration, and greater market power. While MNCs should use appropriate strategic and organizational criteria to select local partners, the host government or local firms can try to make these traits available to attract more stable and profitable foreign direct investment.

The landscape of recombination in African Americans

Abstract: Recombination, together with mutation, gives rise to genetic variation in populations. Here we leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P value < 10(-245)). We identify a 17-base-pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of PRDM9 alleles common in West Africans and rare in Europeans. Sites of this motif are predicted to be risk loci for disease-causing genomic rearrangements in individuals carrying these alleles. More generally, this map provides a resource for research in human genetic variation and evolution.