ANALISIS INVESTASI SAHAM PERUSAHAAN GO PUBLIC SEKTOR PERTANIAN DI BURSA EFEK JAKARTA

Investors, in a capital market, have to observe and analyze the companies’ stock price movements in order to minimize the risk in having stock investments. One of the techniques in analyzing companies’ performance is the stock investment analysis or portfolio analysis. By using the portfolio analysis, this research finds out the best combination of stock investment of PT PP London Sumatera Tbk. (LSIP) and PT Astra Agro Lestari Tbk. (AALI), as go public agricultural companies listed in Jakarta Stock Exchange. After finding the best combination of stock investment of those companies, this research also finds out whether the combination is at the optimum portfolio which would be on the least risk and a particular return or on the highest return and a particular risk. The research was held in 2006 and the data was taken from January 2004 to December 2005. The data was processed by using statistical software in order to minimize the human error. The result shows that there are two best combinations of stock investment on those companies. Those combinations are at the optimum portfolio. The first combination shows 30% of stock investment in LSIP and 70% stock investment in AALI, while the second combination shows 20% stock investment LSIP and 80% stock investment AALI. Investors should choose one of these combinations, because according to the research, these combinations would give them the best return at the least risk

ANALISIS INVESTASI SAHAM PERUSAHAAN GO PUBLIC SEKTOR PERTANIAN DI BURSA EFEK JAKARTA

Investors, in a capital market, have to observe and analyze the companies’ stock price movements in order to minimize the risk in having stock investments. One of the techniques in analyzing companies’ performance is the stock investment analysis or portfolio analysis. By using the portfolio analysis, this research finds out the best combination of stock investment of PT PP London Sumatera Tbk. (LSIP) and PT Astra Agro Lestari Tbk. (AALI), as go public agricultural companies listed in Jakarta Stock Exchange. After finding the best combination of stock investment of those companies, this research also finds out whether the combination is at the optimum portfolio which would be on the least risk and a particular return or on the highest return and a particular risk. The research was held in 2006 and the data was taken from January 2004 to December 2005. The data was processed by using statistical software in order to minimize the human error. The result shows that there are two best combinations of stock investment on those companies. Those combinations are at the optimum portfolio. The first combination shows 30% of stock investment in LSIP and 70% stock investment in AALI, while the second combination shows 20% stock investment LSIP and 80% stock investment AALI. Investors should choose one of these combinations, because according to the research, these combinations would give them the best return at the least risk

The Discovery of Stellar Oscillations in the Planet Hosting Giant Star Beta Geminorum

We present the results of a long time series of precise stellar radial velocity measurements of the planet hosting K giant star Beta Geminorum. A total of 20 hours of observations spanning three nights were obtained and the radial velocity variations show the presence of solar-like stellar oscillations. Our period analysis yields six significant pulsation modes that have frequencies in the range of 30 - 150 microHz. The dominant mode is at a frequency of 86.9 microHz and has an amplitude of 5.3 m/s. These values are consistent with stellar oscillations for a giant star with a stellar mass of approximately 2 solar masses. This stellar mass implies a companion minimum mass of 2.6 Jupiter masses. Beta Gem is the first planet hosting giant star in which multi-periodic stellar oscillations have been detected. The study of stellar oscillations in planet hosting giant stars may provide an independent, and more accurate determination of the stellar mass.Comment: 12 pages preprint, 2 figures, accepted by ApJ Letter

Hyades Oxygen Abundances from the k6300 [O i] Line: The Giant-Dwarf Oxygen Descrepancy Revisited

We present the results of our abundance analysis of Fe, Ni, and O in high signal-to-noise ratio, high-resolution Very Large Telescope UVES and McDonald 2dcoude´ spectra of nine dwarfs and three giants in the Hyades open cluster. The difference in Fe abundances derived from Fe ii and Fe i lines ([Fe ii/HÀ½Fe i/H)and Ni i abundances derived from moderately high-excitation ( %4:20 eV) lines is found to increase with decreasing Teff for the dwarfs. Both of these findings are in concordance with previous results of overexcitation/overionization in cool young dwarfs. Oxygen abundances are derived from the [O i] k6300 line, with careful attention given to the Ni i blend. The dwarf O abundances are in star-to-star agreement within uncertainties, but the abundances of the three coolest dwarfs (4573 K TeA 4834 K) evince an increase with decreasing Teff. Possible causes for the apparent trend are considered,including the effects of overdissociation of O-containing molecules.O abundances are derived from the near-UV OH k3167 line in high-quality Keck HIRES spectra, and no such effects are found; indeed, the OH-based abundances show an increase with decreasing Teff, leaving the nature and reality of the cool dwarf [O i]-based O trend uncertain. The mean relative O abundance of the six warmest dwarfs (5075 K TeA 5978 K) is ½O/H¼þ0:14 Æ0:02, and we find a mean abundance of ½O/H¼þ0:08 Æ0:02for the giants. Thus, our updated analysis of the [O i] k6300 line does not confirm the Hyades giant-dwarf oxygen discrepancy initially reported by King & Hiltgen, suggesting that the discrepancy was a consequence of analysis-related systematic errors. LTE oxygen abundances from the near-IR, high-excitation O i triplet are also derived for the giants, and the resulting abundances are approximately 0.28 dex higher than those derived from the [O i] line, in agreement with non-LTE predictions. Non-LTE corrections from the literature are applied to the giant triplet abundances; the resulting mean abundance is ½O/H¼þ0:17 Æ0:02, in decent concordance with the giant and dwarf [O i] abundances. Finally, Hyades giant and dwarf O abundances derived from the [O i] k6300 line and high-excitation triplet, as well as dwarf O abundances derived from the near-UV OH k3167 line, are compared, and a mean cluster O abundance of ½O/H¼þ0:12 Æ0:02 is achieved, which represents the best estimate of the Hyades O abundance

Research priorities of women at risk for preterm birth: findings and a call to action.

BACKGROUND:Traditional hierarchical approaches to research give privilege to small groups with decision-making power, without direct input from those with lived experience of illness who bear the burden of disease. A Research Justice framework values the expertise of patients and communities as well as their power in creating knowledge and in decisions about what research is conducted. Preterm birth has persisted at epidemic levels in the United States for decades and disproportionately affects women of color, especially Black women. Women of color have not been included in setting the agenda regarding preterm birth research. METHODS:We used the Research Priorities of Affected Communities protocol to elicit and prioritize potential research questions and topics directly from women of color living in three communities that experience disproportionately high rates of preterm birth. Women participated in two focus group sessions, first describing their healthcare experiences and generating lists of uncertainties about their health and/or healthcare during pregnancy. Women then participated in consensus activities to achieve 'top-priority' research questions and topic lists. The priority research questions and topics produced by each group were examined within and across the three regions for similarities and differences. RESULTS:Fifty-four women participated in seven groups (14 sessions) and generated 375 researchable questions, clustered within 22 topics and four overarching themes: Maternal Health and Care Before, During, and After Pregnancy; Newborn Health and Care of the Preterm Baby; Understanding Stress and Interventions to Prevent or Reduce Stress; and Interpersonal and Structural Health Inequities. The questions and topics represent a wide range of research domains, from basic science, translational, clinical, health and social care delivery to policy and economic research. There were many similarities and some unique differences in the questions, topics and priorities across the regions. CONCLUSIONS:These findings can be used to design and fund research addressing unanswered questions that matter most to women at high risk for preterm birth. Investigators and funders are strongly encouraged to incorporate women at the front lines of the preterm birth epidemic in research design and funding decisions, and more broadly, to advance methods to deepen healthcare research partnerships with affected communities

A Planetary Companion to gamma Cephei A

We report on the detection of a planetary companion in orbit around the primary star of the binary system $\gamma$ Cephei. High precision radial velocity measurements using 4 independent data sets spanning the time interval 1981--2002 reveal long-lived residual radial velocity variations superimposed on the binary orbit that are coherent in phase and amplitude with a period or 2.48 years (906 days) and a semi-amplitude of 27.5 m s$^{-1}$. We performed a careful analysis of our Ca II H & K S-index measurements, spectral line bisectors, and {\it Hipparcos} photometry. We found no significant variations in these quantities with the 906-d period. We also re-analyzed the Ca II $\lambda$8662 {\AA} measurements of Walker et al. (1992) which showed possible periodic variations with the ``planet'' period when first published. This analysis shows that periodic Ca II equivalent width variations were only present during 1986.5 -- 1992 and absent during 1981--1986.5. Furthermore, a refined period for the Ca II $\lambda$8662 {\AA} variations is 2.14 yrs, significantly less than residual radial velocity period. The most likely explanation of the residual radial velocity variations is a planetary mass companion with $M$ sin $i$ = 1.7 $M_{Jupiter}$ and an orbital semi-major axis of $a_2$ $=$ 2.13 AU. This supports the planet hypothesis for the residual radial velocity variations for $\gamma$ Cep first suggested by Walker et al. (1992). With an estimated binary orbital period of 57 years $\gamma$ Cep is the shortest period binary system in which an extrasolar planet has been found. This system may provide insights into the relationship between planetary and binary star formation.Comment: 19 pages, 15 figures, accepted in Ap. J. Includes additional data and improved orbital solutio

The 1995-1996 Decline of R Coronae Borealis - High Resolution Optical Spectroscopy

A set of high-resolution optical spectra of RCrB acquired before, during, and after its 1995-1996 decline is discussed. All of the components reported from earlier declines are seen. This novel dataset provides new information on these components including several aspects not previously seen in declines of RCrB and other RCBs. In the latter category is the discovery that the decline's onset is marked by distortions of absorption lines of high-excitation lines, and quickly followed by emission in these and in low excitation lines. This 'photospheric trigger' implies that dust causing the decline is formed close to the star. These emission lines fade quickly. After 1995 November 2, low excitation narrow (FWHM ~12 km s-1) emission lines remain. These appear to be a permanent feature, slightly blue-shifted from the systemic velocity, and unaffected by the decline except for a late and slight decrease of flux at minimum light. The location of the warm, dense gas providing these lines is uncertain. Absorption lines unaffected by overlying sharp emission are greatly broadened, weakened, and red-shifted at the faintest magnitudes when scattered light from the star is a greater contributor than direct light transmitted through the fresh soot cloud. A few broad lines are seen at and near minimum light with approxiamately constant flux: prominent among these are the He I triplet series, Na I D, and [N II] lines. These lines are blue-shifted by about 30 km s(-1) relative to the systemic velocity with no change in velocity over the several months for whicht he lines were seen. It is suggested that these lines, especially the He I lines, arise from an accretion disk around an unseen compact companion, which may be a low-mass white dwarf. If so, R CrB is similar to the unusual post-AGB star 89 Her.Comment: 31 pages, 26 figure

High-Resolution Spectroscopy of the Planetary Host HD 13189: Highly-Evolved and Metal-Poor

We report on the abundances of 13 elements in the planetary host HD 13189, a massive giant star. Abundances are found to be sub-solar, with [Fe/H] = -0.58 +/- 0.04$; HD 13189 is one of the most metal-poor planetary hosts yet discovered. Abundance ratios relative to Fe show no peculiarities with respect to random field stars. A census of metallicities of the seven currently known planet-harboring giants results in a distribution that is more metal-poor than the well-known metal-rich distribution of main sequence (MS) planetary hosts. This finding is discussed in terms of accretion of H-depleted material, one of the possible mechanisms responsible for the high-metallicity distribution of MS stars with planets. We estimate the mass of the HD 13189 progenitor to be 3.5 M_sun but cannot constrain this value to better than 2-6 M_sun. A stellar mass of 3.5 M_sun implies a planetary mass of m sin i = 14.0 +/- 0.8 M_J, placing the companion at the planet/brown dwarf boundary. Given its physical characteristics, the HD 13189 system is potentially unique among planetary systems, and its continued investigation should provide invaluable data to extrasolar planetary research.Comment: 14 pages, 2 figures; Accepted for publication in ApJ Letter

On the Stellar Companion to the Exoplanet Hosting Star 30 Arietis B

A crucial aspect of understanding planet formation is determining the binarity of the host stars. Results from radial velocity (RV) surveys and the follow-up of Kepler exoplanet candidates have demonstrated that stellar binarity certainly does not exclude the presence of planets in stable orbits and the configuration may in fact be relatively common. Here we present new results for the 30 Arietis system which confirms that the B component hosts both planetary and stellar companions. Keck AO imaging provides direct detection of the stellar companion and additional RV data are consistent with an orbiting star. We present a revised orbit of the known planet along with photometry during predicted transit times. Finally, we provide constraints on the properties of the stellar companion based on orbital stability considerations

Searching for Planets in the Hyades. I. The Keck Radial Velocity Survey

We describe a high-precision radial velocity search for jovian-mass companions to main sequence stars in the Hyades star cluster. The Hyades provides an extremely well controlled sample of stars of the same age, the same metallicity, and a common birth and early dynamical environment. This sample allows us to explore the dependence of the process of planet formation on only a single independent variable: the stellar mass. In this paper we describe the survey and summarize results for the first five years.Comment: 8 pages, 3 figures; To appear in the July 2002 issue of The Astronomical Journa