Embriogenesis somatica en reproduccion in vitro del cultivo de piña (Ananas comosus L. Merr) cultivar MD-2

La piña es reconocida como una de las frutas más finas de las re giones tropicales y se denomina la reina de todas las frutas. En Nicaragua se consume principalmente como frut a fresca, refresco y otros productos derivados de la industrialización de la piña. Para el estudio de embriogénesis somática en piña cultivar MD - 2 se realizaron diferentes variantes de medios de cultivo en las fases de inducción, multiplicación, formación de plantas , enraizamiento y aclimatación de plantas. En la fase de inducción de callo s con el empleo de explante s de hojas no se produjo iniciación de callos, pero con explantes de ápices meristemáticos se obtuvieron los mejores resultados en los medios qu e contenían 1 mg/l de 2,4 - D y 0 y 0.2 mg/l 6 - B encil - amino - purina . La multiplicación de callos fue mejor en los medios de cultivos que se le suministraron 2 mg/l de Ácido Indolacético y 1.8 mg/l de A cido - naftaleno - acético con agua de coco al 1 5% y 400 mg/ l de carbón activado . La formaci ón de pla n tas se favoreció en el medio de cultivo que contenía 0.38 mg/l de Ácido Indolbutírico y dos mg/l de 6 - Bencil - Amino - Purina. En l a fase de enraizamiento de las plantas resultó ser mejor el medio de cultivo que con tenía 0.5 mg/l de Ácido Indolacé tico y 40 g/l de sacarosa . En la fase de aclimat iz ación de plantas los medios que previamente se desarrollaron en las cinco variantes de medios en la fase de en raizamiento presentaron los mejores resultados con respecto al po rcen taje de sobrevivencia.

PICES Press, Vol. 14, No. 2, July 2006

The 2006 inter-sessional Science Board and Governing Council meeting: A note from the Chairman (pdf, 0.1 Mb) Future Integrative Science Program – Progress report (pdf, 0.2 Mb) Big-picture synthesis requires understanding the small and "in-between" stuff - A summary of the CCCC Synthesis Symposium (pdf, 0.4 Mb) PICES Calendar (pdf, 0.4 Mb) Integration of ecological indicators for the North Pacific with emphasis on the Bering Sea (pdf, 0.2 Mb) Time series of the Northeast Pacific: A symposium to mark the 50th anniversary of Line-P (pdf, 0.1 Mb) PICES hosts an ESSAS workshop in St. Petersberg, Russia (pdf, 0.2 Mb) Professor Mikhail N. Koshlyakov (pdf, 0.5 Mb) The state of the western North Pacific in the second half of 2005 (pdf, 0.8 Mb) Recent trends in waters of the subarctic NE Pacific (pdf, 0.2 Mb) Unusual invertebrates and fish observed in the Gulf of Alaska, 2004-2005 (pdf, 0.1 Mb) The Bering Sea: Current status and recent events (pdf, 0.2 Mb) The Year of the Euphausiid (pdf, 0.01 Mb) Michio J. Kishi awarded 2005 Uda Prize by the Japan Society of Fisheries Oceanography (pdf, 0.03 Mb)

PICES Press, Vol. 12, No. 2, July 2004

The future of PICES [pdf, 1.7 MB] Paris by day - Symposium on "Quantative ecosystem indicators in fisheries management" [pdf, 0.2 MB] The Bering Sea: Current status and recent events [pdf, 0.4 MB] The state of the western North Pacific in the second half of 2003 [pdf, 0.7 MB] The state of the eastern North Pacific entering spring 2004 [pdf, 0.4 MB] PICES-IFEP Workshop on "In-situ iron enrichment experiments in the eastern and western subarctic Pacific" [pdf, 1.4 MB] Canadian SOLAS/PICES-IFEP session on "Response of the upper ocean to meso-scale iron enrichment" [pdf, 0.3 MB] Fisheries and ecosystem responses to recent regime shifts [pdf, 0.8 MB] PICES Interns [pdf, 0.8 MB] Did a regime shift occur in 1998 around Japan?- Highlights from a symposium addressing this question [pdf, 0.8 MB] The Global Ocean Carbon Observing System - Connecting national programs and regional networks [pdf, 1.7 MB] The North Pacific Ecosystem Metadatabase [pdf, 1.2 MB] International GLOBEC Symposium on "Climate variability and Sub-Arctic marine ecosystems" [pdf, 0.2 MB] PICES Calendar [pdf, 0.2 MB] PICES/GLOBEC Symposium on "Climate variability and ecosystem impacts on the North pacific: A basin-scale synthesis" [pdf, 0.2 MB]

PICES Press, Vol. 11, No. 2, July 2003

Cover [pdf, 1.2 Mb] PICES Science Board and Governing Council hold their first joint meeting [pp. 1-3] [pdf, 0.2 Mb] 3rd International Zooplankton Production Symposium [pp. 4-7] [pdf, 0.6 Mb] The state of the eastern North Pacific entering spring 2003 [pp. 8-9] [pdf, 0.4 Mb] The state of the western North Pacific in 2002 [pp. 10-13] [pdf, 0.6 Mb] The Bering Sea: Current status and recent events [pp. 14-15] [pdf. 0.7 Mb] Patricia Livingston [pp. 16-19] [pdf. 0.5 Mb] Recent changes in the abundance of northern anchovy (Engraulis mordax) off the Pacific Northwest, tracking a regime shift? [pp. 20-21] [pdf. 0.6 Mb] Developing new scientific programs in PICES [pp. 22-26] [pdf. 0.2 Mb] Report of the Yokohama 2003 MODEL Task Team Workshop to develop a marine ecosystem model of the North Pacific Ocean including pelagic fishes [pp. 27-29] [pdf. 0.5 Mb] 3rd PICES Workshop on the Okhotsk Sea and adjacent Areas [pp.30-31] [pdf. 0.4 Mb] Recent oceanographic and marine environmental studies at FERHRI [pp.32-34] [pdf. 0.4 Mb] Symposium Announcement [p. 35] [pdf. 0.3 Mb] PICES announcements [p. 36] [pdf. 0.3 Mb]

PICES Press, Vol. 10, No. 2, July 2002

International symposium on North Pacific transitional areas [pp. 1-4] [pdf, 0.8 Mb] PICES Volunteer Observing Ship (VOS) Workshop [pp. 5-7] [pdf, 0.3 Mb] Joint meeting on Causes of marine mortality of salmon [pp. 8-9] [pdf, 0.3 Mb] The state of the western North Pacific in the second half of 2001 [pp. 10-11] [pdf, 0.5 Mb] State of the eastern North Pacific in spring 2002 [pp. 12-13] [pdf. 0.4 Mb] The status of the Bering Sea in the second half of 2001 [pp. 14-15] [pdf. 0.3 Mb] PICES Workshop on “Perturbation analysis” on subarctic Pacific gyre ecosystem models [pp. 16-17] [pdf. 0.4 Mb] Status and future plans for SOLAS-Japan [pp. 18-20] [pdf. 0.5 Mb] China-Korea Joint Ocean Research Center: A bridge across the Yellow Sea to connect Chinese and Korean oceanographic institutes and scientists [pp. 21-22] [pdf. 0.3 Mb] Persistent changes in the California Current ecosystem [pp. 23-24] [pdf. 0.2 Mb] The Hokusei Maru: 53 years of research in the Pacific [pp. 25-28] [pdf. 0.5 Mb] First meeting of the CLIVAR Pacific Panel [pp. 29-30] [pdf. 0.3 Mb] Call for contributions to the North Pacific Ecosystem Status Report [p. 31] [pdf. 0.2 Mb] PICES announcements [p. 32] [pdf. 0.2 Mb]

PICES Press, Vol. 9, No. 2, July 2001

Cover [pdf, 0.2 Mb] Climate, biodiversity and ecosystems of the North Pacific [pp. 1-2] [pdf, 0.2 Mb] The state of the western North Pacific in the second half of 2000 [pp. 3-5] [pdf, 0.8 Mb] The status of the Bering Sea: June – December 2000 [pp. 6-7] [pdf, 1.5 Mb] The state of the eastern North Pacific since autumn 2000 [p. 8] [pdf, 0.3 Mb] Korean Yellow Sea Large Marine Ecosystem Program [pp. 9-12] [pdf, 0.5 Mb] Past and ongoing Mexican ecosystem research in the northeast Pacific Ocean [pp. 13-15] [pdf, 0.3 Mb] Vera Alexander [pp. 16-19] [pdf, 1.0 Mb] North Pacific CO2 data for the new millennium [pp. 20-21] [pdf, 0.3 Mb] PICES Higher Trophic Level Modelling Workshop [pp. 22-23] [pdf, 0.4 Mb] Argo Science Team 3rd Meeting (AST-3) [pp. 24-25] [pdf, 0.3 Mb] 2001 coast ocean / salmon ecosystem event [p. 26-27] [pdf, 0.3 Mb] Shifts in zooplankton abundance and species composition off central Oregon and southwestern British Columbia [pp. 28-29] [pdf, 0.3 Mb] The CLIVAR - Pacific Workshop [p. 30] [pdf, 0.2 Mb] PICES dialogue with Mexican scientists [p. 31] [pdf, 0.2 Mb] Announcements [p. 32] [pdf, 0.2 Mb]

锰含量对LiNi_(0.85-x)Co_(0.15)Mn_xO_2结构及形貌的影响

采用共沉淀法先合成出氢氧化物前驱体Ni0.85-xCo0.15Mnx(OH)2,其中X=0、0.1、0.2和0.4,前驱体与Li2CO3在空气气氛中固相烧结制得正极材料LiNi0.85-xCo0.15MnxO2。用XRD、SEM研究了锰含量对材料结构和形貌的影响。研究发现,LiNi0.85Co0.15O2的X射线衍射图中存在微量第二相,而锰掺杂有利于减小反应过程中锂离子损失和镍离子占据锂位,容易形成有序层状结构材料。随着Mn离子替代Ni离子量的增加,晶胞参数a减小,晶胞参数c、c/a及I003/I104值增大。SEM结果表明前驱体和最终产物形貌均随锰含量增加颗粒均匀性增强,粒子尺寸变小,粒径分布变窄。

PICES Press, Vol. 16, No. 2, July 2008

The 2008 Inter-Sessional Science Board Meeting (pp.1-2, pdf, 0.1 Mb) FUTURE – From Science Plan to Implementation Plan (pp. 3-4, pdf, 0.1 Mb) CFAME Task Team Workshop – Linking and Visualising (p. 5, pdf, 0.1 Mb) PICES WG 21 Meets in Busan, Korea: The Database Meeting (pp. 6-7, pdf, 0.1 Mb) ICES-PICES-IOC Symposium on Climate Change (pp. 8-12, pdf, 1.2 Mb) Zooplankton and Climate: Response Modes and Linkages (pp. 13-15, pdf, 0.2 Mb) PICES Fishery Science Committee Workshop in Gijón (pp. 16-18, pdf, 0.1 Mb) The North Pacific Continuous Plankton Recorder Survey (pp. 19-21, pdf, 0.4 Mb) PICES Ecosystem Status Report Wins Design Award (p. 21, pdf, 0.4 Mb) Canada’s Three Oceans (C3O): A Canadian Contribution to the International Polar Year (pp. 22-25, pdf, 0.8 Mb) New Surface Mooring at Station Papa Monitors Climate (pp. 26-27, pdf, 0.2 Mb) The State of the Western North Pacific in the Second Half of 2007 (pp. 28-29, pdf, 0.4 Mb) The Bering Sea: Current Status and Recent Events (pp. 30-31, pdf, 0.4 Mb) Recent Trends in Waters of the Subarctic NE Pacific (pp.32-33, pdf, 0.3 Mb) 2009 Vintage of Fraser River Sockeye Salmon: A Complex Full Bodied Redd with Mysterious Bouquet (p. 34, pdf, 0.1 Mb) Pacific Biological Station Celebrates Centennial Anniversary, 1908–2008 (p. 35, pdf, 0.3 Mb) Marine and Coastal Fisheries: American Fisheries Society Open Access E-journal (p. 36, pdf, 0.1 Mb) Latest and Upcoming PICES Publications (p. 36, pdf, 0.1 Mb)

PICES Press, Vol. 17, No. 2, July 2009

Major Outcomes from the 2009 PICES Annual Meeting: A Note from the Chairman (pdf, 0.1 Mb) The FUTURE is Here (pdf, 0.1 Mb) PICES Harmful Algal Bloom International Seafood Safety Project (pdf, 0.3 Mb) PICES at the 2009 GLOBEC Open Science Meeting (pdf, 0.4 Mb) Modeling Ecosystems and Ocean Processes Workshop (pdf, 0.1 Mb) Krill Biology and Ecology Workshop (pdf, 0.1 Mb) Polar and Sub-Polar Marine Ecosystems Workshop (pdf, 0.4 Mb) Biogeochemistry of the Oceans in a Changing Climate Workshop (pdf, 0.1 Mb) Continuous Plankton Recorder Surveys of the Global Oceans (pdf, 0.4 Mb) Plankton Phenology Workshop (pdf, 0.2 Mb) Workshop on “Climate Impact on Ecosystem Dynamics of Marginal Seas” (pdf, 0.1 Mb) Erratum (pdf, 0.4 Mb) The State of the Western North Pacific in the Second Half of 2008 (pdf, 0.2 Mb) State of the Northeast Pacific into early 2009 (pdf, 0.1 Mb) Current Status of the Bering Sea Ecosystem (pdf, 0.1 Mb) 2009 Salmon Forecasting Forum (pdf, 0.3 Mb) The Third Argo Science Workshop: “The Future of Argo” (pdf, 0.1 Mb) 2009 ESSAS Annual Science Meeting (pdf, 0.1 Mb) A Visit Fit for an Emperor and Empress of Japan (pdf, 0.9 Mb)

2,4-dimethylene-1,3-cyclobutanediyl and 2,4-dimethylenebicyclobutane. Synthesis, spectroscopy, and reactivity of a triplet biradical and its covalent isomer

The preparation and direct observation of triplet 2,4-dimethylene-1,3- cyclobutanediyl (1), the non-Kekule isomer of benzene, is described. The biradical was generated by photolysis of 5,6-dimethylene-2,3- diazabicyclo[2.1.1]hex-2-ene (2) (which was synthesized in several steps from benzvalene) under cryogenic, matrix-isolation conditions. Biradical 1 was characterized by EPR spectroscopy (‌‌‌‌‌│D/hc│ =0.0204 cm^(-1), │E/hc│ =0.0028 cm^(-1)) and found to have a triplet ground state. The Δm_s= 2 transition displays hyperfine splitting attributed to a 7.3-G coupling to the ring methine and a 5.9-G coupling to the exocyclic methylene protons. Several experiments, including application of the magnetophotoselection (mps) technique in the generation of biradical 1, have allowed a determination of the zero-field triplet sublevels as x = -0.0040, y = +0.0136, and z = -0.0096 cm^(-1), where x and y are respectively the long and short in-plane axes and z the out-of-plane axis of 1.

Triplet 1 is yellow-orange and displays highly structured absorption (λ_(max)= 506 nm) and fluorescence (λ_(max) = 510 nm) spectra, with vibronic spacings of 1520 and 620 cm^(-1) for absorption and 1570 and 620 cm^(-1) for emission. The spectra were unequivocally assigned to triplet 1 by the use of a novel technique that takes advantage of the biradical's photolability. The absorption є = 7200 M^(-1) cm^(-1) and f = 0.022, establishing that the transition is spin-allowed. Further use of the mps technique has demonstrated that the transition is x-polarized, and the excited state 1s therefore of B_(1g) symmetry, in accord with theoretical predictions.

Thermolysis or direct photolysis of diazene 2 in fluid solution produces 2,4- dimethylenebicyclo[l.l.0]butane (3), whose ^(l)H NMR spectrum (-80°C, CD_(2)Cl_(2)) consists of singlets at δ 4.22 and 3.18 in a 2:1 ratio. Compound 3 is thermally unstable and dimerizes with second-order kinetics between -80 and -25°C (∆H^(‡) = 6.8 kcal mol^(-1), (∆s^(‡) = -28 eu) by a mechanism involving direct combination of two molecules of 3 in the rate-determining step. This singlet-manifold reaction ultimately produces a mixture of two dimers, 3,8,9- trimethylenetricyclo[5.1.1.0^(2,5)]non-4-ene (75) and trans-3,10-dimethylenetricyclo[6.2.0.0^(2,5)]deca-4,8-diene (76t), with the former predominating. In contrast, triplet-sensitized photolysis of 2, which leads to triplet 1, provides, in addition to 75 and 76t, a substantial amount of trans-5,10- dimethylenetricyclo[6.2.0.0^(3,6)]deca-3,8-diene (77t) and small amounts of two unidentified dimers.

In addition, triplet biradical 1 ring-closes to 3 in rigid media both thermally (77-140 K) and photochemically. In solution 3 forms triplet 1 upon energy transfer from sensitizers having relatively low triplet energies. The implications of the thermal chemistry for the energy surfaces of the system are discussed.

Measurement of the neutron (^3He) spin structure function at low Q^2 : a connection between the Bjorken and Drell-Hearn-Gerasimov sum rules

The spin dependent cross sections, σT_1/2 and σT_3/2 , and asymmetries, A_∥ and A_⊥ for ³He have been measured at the Jefferson Lab's Hall A facility. The inclusive scattering process ³He(e,e)X was performed for initial beam energies ranging from 0.86 to 5.1 GeV, at a scattering angle of 15.5°. Data includes measurements from the quasielastic peak, resonance region, and the deep inelastic regime. An approximation for the extended Gerasimov-Drell-Hearn integral is presented at a 4-momentum transfer Q² of 0.2-1.0 GeV².

Also presented are results on the performance of the polarized ³He target. Polarization of ³He was achieved by the process of spin-exchange collisions with optically pumped rubidium vapor. The ³He polarization was monitored using the NMR technique of adiabatic fast passage (AFP). The average target polarization was approximately 35% and was determined to have a systematic uncertainty of roughly ±4% relative.

Measurement of the galactic cosmic ray antiproton flux from 0.25 gev to 3.11 gev with the isotope matter antimatter experiment (imax)

The intensities and relative abundances of galactic cosmic ray protons and antiprotons have been measured with the Isotope Matter Antimatter Experiment (IMAX), a balloon-borne magnet spectrometer. The IMAX payload had a successful flight from Lynn Lake, Manitoba, Canada on July 16, 1992. Particles detected by IMAX were identified by mass and charge via the Cherenkov-Rigidity and TOP-Rigidity techniques, with measured rms mass resolution ≤0.2 amu for Z=1 particles.

Cosmic ray antiprotons are of interest because they can be produced by the interactions of high energy protons and heavier nuclei with the interstellar medium as well as by more exotic sources. Previous cosmic ray antiproton experiments have reported an excess of antiprotons over that expected solely from cosmic ray interactions.

Analysis of the flight data has yielded 124405 protons and 3 antiprotons in the energy range 0.19-0.97 GeV at the instrument, 140617 protons and 8 antiprotons in the energy range 0.97-2.58 GeV, and 22524 protons and 5 antiprotons in the energy range 2.58-3.08 GeV. These measurements are a statistical improvement over previous antiproton measurements, and they demonstrate improved separation of antiprotons from the more abundant fluxes of protons, electrons, and other cosmic ray species.

When these results are corrected for instrumental and atmospheric background and losses, the ratios at the top of the atmosphere are p/p=3.21(+3.49, -1.97)x10^(-5) in the energy range 0.25-1.00 GeV, p/p=5.38(+3.48, -2.45) x10^(-5) in the energy range 1.00-2.61 GeV, and p/p=2.05(+1.79, -1.15) x10^(-4) in the energy range 2.61-3.11 GeV. The corresponding antiproton intensities, also corrected to the top of the atmosphere, are 2.3(+2.5, -1.4) x10^(-2) (m^2 s sr GeV)^(-1), 2.1(+1.4, -1.0) x10^(-2) (m^2 s sr GeV)^(-1), and 4.3(+3.7, -2.4) x10^(-2) (m^2 s sr GeV)^(-1) for the same energy ranges.

The IMAX antiproton fluxes and antiproton/proton ratios are compared with recent Standard Leaky Box Model (SLBM) calculations of the cosmic ray antiproton abundance. According to this model, cosmic ray antiprotons are secondary cosmic rays arising solely from the interaction of high energy cosmic rays with the interstellar medium. The effects of solar modulation of protons and antiprotons are also calculated, showing that the antiproton/proton ratio can vary by as much as an order of magnitude over the solar cycle. When solar modulation is taken into account, the IMAX antiproton measurements are found to be consistent with the most recent calculations of the SLBM. No evidence is found in the IMAX data for excess antiprotons arising from the decay of galactic dark matter, which had been suggested as an interpretation of earlier measurements. Furthermore, the consistency of the current results with the SLBM calculations suggests that the mean antiproton lifetime is at least as large as the cosmic ray storage time in the galaxy (~10^7 yr, based on measurements of cosmic ray ^(10)Be). Recent measurements by two other experiments are consistent with this interpretation of the IMAX antiproton results.

Growth and characterization of high-quality LiAlO2 single crystal

g-LiAlO2 single crystal is a promising substrate for GaN heteroepitaxy. In this paper, we present the growth of large-sized LiAlO2 crystal by modified Czochralski method. The crystal quality was characterized by high-resolution X-ray diffraction and chemical etching. The results show that the as-grown crystal has perfect quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec and etch pits density of (0.3-2.2) x 10(4) cm(-2) throughout the crystal boule. The bottom of the crystal boule shows the best quality. The optical transmission spectra from UV to IR exhibits that the crystal is transparent from 0.2 to 5.5 mu m and becomes completely absorbing around 6.7 mu m wavelength. The optical absorption edge in near UV region is about 191 nm.

利用微量热法研究Cd~(2+)和Cu~(2+)对嗜热四膜虫(Tetrahymena thermophila)的毒性效应

利用微量热法研究Cd2 + 和Cu2 + 对嗜热四膜虫BF5(TetrahymenathermophilaBF5)生长代谢毒性效应 ,结果表明 :①低浓度的Cd2 + (0～ 0 .4mgL-1)和Cu2 + (0～ 10mgL-1)对四膜虫的生长有促进作用 ,而高浓度的Cd2 + (0 .8～ 3.2mgL-1)和Cu2 + (2 0～ 2 0 0mgL-1)则产生抑制作用 ;②Cd2 + 和Cu2 + 的半抑制浓度IC50 分别为 2 .0 4mg/L和15 5 .5mg/L ;③联合毒性为协同作用

Elevated levels of urinary 8-hydroxy-2'-deoxyguanosine in male electrical and electronic equipment dismantling workers exposed to high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenyl ethers, and polychlorinated biphenyls

To investigate the occupational exposure levels to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), indoor dust (n = 3) in workshops and hair samples from male workers (n = 64) were collected at two electrical and electronic equipment waste (E-waste) dismantling factories located in the LQ area in east China in July 11-13, 2006. Pre- and postworkshift urines (64 of each) were also collected from the workers to study oxidative damage to DNA using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker. The concentrations of PCDD/Fs, PCDD/F-WHO-TEQs, PBDEs, PCBs and PCB-WHO-TEQs were (50.0 +/- 8.1) x 10(3), 724.1 +/- 249.6, (27.5 +/- 5.8) x 10(6), (1.6 +/- 0.4) x 10(9), (26.2 +/- 3.0) x 10(3) pg/g dry weight (dw) in dust, and (2.6 +/- 0.6) x 10(3), 42.4 +/- 9.3, (870.8 +/- 205.4) x 10(3), (1.6 +/- 0.2) x 10(6), 41.5 +/- 5.5 pg/g dw in hair, respectively. The homologue and congener profiles in the samples demonstrated that high concentrations of PCDD/Fs, PBDEs, and PCBs were originated from open burning of E-waste. The 8-OHdG levels were detected at 6.40 +/- 1.64 mu mol/mol creatinine in preworkshift urines. However, the levels significantly increased to 24.55 +/- 5.96 mu mol/mol creatinine in postworkshift urines (p < 0.05). Then, it is concluded that there is a high cancer risk originated from oxidative stress indicated by the elevated 8-OHdG levels in the E-waste dismantling workers exposed to high concentrations of PCDD/Fs, PBDEs, and PCBs.