Methane dynamics in Santa Barbara Basin (USA) sediments as examined with a reaction-transport model

Here we describe a new reaction-transport model that quantitatively examines δ13C profiles of pore-water methane and dissolved inorganic carbon (DIC) (δ13CCH4 and δ13CDIC) in the anoxic sediments of the Santa Barbara Basin (California Borderland region). Best-fit solutions of the model to these data suggest that CO2 reduction is the predominant form of methanogenesis in these sediments. These solutions also accurately reproduce the isotope depth profiles, including a broad minimum in the δ13CDIC profile and a much sharper (angular) minimum in the δ13CCH4 profile, both of which appear near the base of the transition zone in the sediments between sulfate reduction and methanogenesis (referred to here as the sulfate-methane transition zone, or SMTZ). Such minima in pore-water profiles of δ13CCH4 near the base of the SMTZ have been seen in a number of other marine sediments across a range of depth and timescales. We show here that this minimum in the δ13CCH4 profile in Santa Barbara Basin sediments results from the balance between (1) anaerobic oxidation of methane (AOM), which leads to an increase in δ13CCH4 with decreasing depth in the sediment column through and above the SMTZ; (2) methanogenesis, which produces 13C-depleted methane, both in and below the SMTZ; and (3) an upward flux of CH4 from depth that is relatively enriched in 13C as compared with the methane in these pore waters. Possible sources of this deep methane include the following: geologic hydrocarbon reservoirs derived from ancient source rocks; decomposition of buried gas hydrates; and biogenic (or perhaps thermogenic) methane produced hundreds of meters below the seafloor stimulated by increasing temperatures associated with the sediment geothermal gradient. Although we are unable to resolve these possible sources of deep methane, we believe that the significance of an upward methane flux as an explanation for minima in δ13CCH4 pore-water profiles may not be limited to Santa Barbara Basin sediments but may be common in many continental margin sediments

Carbon Cycling in Santa Barbara Basin Sediments: A Modeling Study

The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits yield results consistent with previous studies of Santa Barbara Basin and other continental margin sediments. These results indicate that authigenic carbonate precipitation in these sediments is not centered around the sulfate-methane transition zone (SMTZ), as is seen in many other sedimentary environments but occurs at shallower depths in the sediments and over a relatively broad depth range. Sulfate profiles are linear between the surface sediments (upper ∼20 cm) and the top of the SMTZ (∼105 cm) giving the appearance of refractory particulate organic carbon (POC) burial and conservative sulfate behavior in this intermediate region. However, model results show that linear profiles may also occur when high rates of sulfate reduction occur near the sediment surface (as organoclastic sulfate reduction [oSR]) and in the SMTZ (largely as anaerobic oxidation of methane) with low, but nonzero, rates of oSR in-between. At the same time, linearity in the sulfate profile may also be related to downward pore-water advection by compaction and sedimentation plus a decrease with depth in sulfate diffusivity because of decreasing porosity. These model-determined rates of oSR and methanogenesis also result in a rate of POC loss that declines near-continuously in a logarithmic fashion over the entire sediment column studied. The results presented further here indicate the importance of a deep methane flux from below on sediment biogeochemistry in the shallower sediments, although the exact source of this methane flux is difficult to ascertain with the existing data

PENGEMBANGAN BISKUIT MP-ASI DENGAN PENAMBAHAN PUREE LABU KUNING (Cucurbita moschata) DAN TEPUNG BERAS MERAH (Oryza nivara)

Makanan pendamping air susu ibu (MP-ASI) merupakan makanan pendamping dari air susu ibu yang disiapkan untuk membantu memenuhi kebutuhan gizi bayi. MP-ASI diberikan kepada bayi ketika air susu ibu sudah tidak cukup dalam memenuhi kebutuhan gizi anak. Pada bayi usia 12-24 bulan mulai diperkenalkan dengan jenis makanan padat seperti biskuit sebagai MP-ASI. Biskuit MP-ASI dapat dikembangkan melalui pemanfaatan bahan pangan lokal seperti labu kuning yang memiliki kandungan beta karoten dan tepung beras merah yang memiliki kandungan protein. Puree labu kuning merupakan bentuk produk olahan dari buah labu kuning dengan pemberian proses pengukusan. Tepung beras merah merupakan bentuk produk olahan dari beras merah. Penelitian ini bertujuan untuk mendapatkan biskuit MP-ASI yang mampu memberikan kandungan gizi terbaik seperti vitamin A dan protein, untuk mengetahui pengaruh penambahan puree labu kuning dan tepung beras merah pada biskuit MP-ASI, selain itu juga mengetahui tingkat kesukaan pada masing-masing formulasi biskuit. Pada penelitian ini menggunakan 4 formulasi biskuit MP-ASI, yaitu biskuit kontrol tanpa penambahan puree labu kuning dan tepung beras merah, biskuit formulasi 1 dengan penambahan 5% tepung beras merah dan 10% puree labu kuning, biskuit formulasi 2 dengan penambahan 7,5% tepung beras merah dan 7,5% puree labu kuning, serta biskuit formulasi 3 dengan penambahan 10% tepung beras merah dan 5% puree labu kuning. Analisa yang dilakukan dalam penelitian ini adalah analisa fisik, analisa kimiawi, dan analisa organoleptik. Pada analisa fisik warna yang terbaik dimiliki biskuit kontrol dan analisa tekstur terkeras dimiliki biskuit formulasi 3 dan formulasi terlunak dimiliki biskuit formulasi 1 dengan penambahan puree labu kuning terbanyak. Analisa kimiawi yang dilakukan menghasilkan biskuit formulasi 3 memiliki kadar abu tertinggi yaitu 1,63%, kadar protein tertinggi yaitu 6,16%. Kadar air tertinggi dimiliki biskuit formulasi 1 yaitu 4,80%, kadar lemak teringgi dimiliki biskuit kontrol sebesar 37,59%, dan kadar karbohidrat tertinggi dimiliki biskuit formulasi 2 yaitu sebesar 56,61%. Kadar beta karoten tertinggi dimiliki biskuit formulasi 1 yaitu sebesar 4,32 mg/100 gram produk. Hasil analisa organoleptik biskuit MP-ASI kontrol memiliki tingkat kesukaan overall tertinggi dengan rata-rata 2,88. Selain itu biskuit formulasi 1 merupakan formulasi yang agak disukai disukai panelis dengan rata-rata 2,65 dengan penambahan 10% puree labu kuning dan 5% tepung beras merah

Di-Pion Decays of Heavy Quarkonium in the Field Correlator Method

Mechanism of di-pion transitions $nS\to n'S\pi\pi(n=3,2; n'=2,1)$ in bottomonium and charmonium is studied with the use of the chiral string-breaking Lagrangian allowing for the emission of any number of $\pi(K,\eta),$ and not containing fitting parameters. The transition amplitude contains two terms, $M=a-b$, where first term (a) refers to subsequent one-pion emission: $\Upsilon(nS)\to\pi B\bar B^*\to\pi\Upsilon(n'S)\pi$ and second term (b) refers to two-pion emission: $\Upsilon(nS)\to\pi\pi B\bar B\to\pi\pi\Upsilon(n'S)$. The one-parameter formula for the di-pion mass distribution is derived, $\frac{dw}{dq}\sim$(phase space) $|\eta-x|^2$, where $x=\frac{q^2-4m^2_\pi}{q^2_{max}-4m^2_\pi},$ $q^2\equiv M^2_{\pi\pi}$. The parameter $\eta$ dependent on the process is calculated, using SHO wave functions and imposing PCAC restrictions (Adler zero) on amplitudes a,b. The resulting di-pion mass distributions are in agreement with experimental data.Comment: 62 pages,8 tables,7 figure

Closed-flavor pi + J/psi and pi + Upsilon Cross Sections at Low Energies from Dipion Decays

The scale of low energy c-cbar and b-bbar cross sections on light hadrons is of great importance to searches for the quark gluon plasma using the heavy-quarkonium suppression signature. Unfortunately, little is known about these near-threshold cross sections at present, and recent theoretical estimates span many orders of magnitude. Here we use experimental data on the four observed closed-flavor heavy quarkonium hadronic decays psi' -> pi pi J/psi, Upsilon' -> pi pi Upsilon, Upsilon'' -> pi pi Upsilon and Upsilon'' -> pi pi Upsilon', combined with simple models of the transition amplitudes, to estimate the pion scattering cross sections of c-cbar and b-bbar mesons near threshold. Specifically we consider the closed-flavor reactions pi J/psi -> pi psi', pi Upsilon -> pi Upsilon', pi Upsilon -> pi Upsilon'' and pi Upsilon' -> pi Upsilon'' and their time-reversed analogues. Our results may be useful in constraining theoretical models of the strong interactions of heavy quarkonia, and can be systematically improved through future detailed studies of dipion decays, notably psi' -> pi pi J/psi and Upsilon'' -> pi pi Upsilon.Comment: 6 pages, 6 figure

Experimental and theoretical evidences for an intermediate σ\sigma-dressed dibaryon in the NN interaction

Numerous theoretical and experimental arguments are presented in favor of the generation of intermediate $\sigma$-dressed dibaryon in $NN$ interaction at intermediate and short distances. We argue that this intermediate dibaryon can be responsible for the strong intermediate-range attraction and the short-range repulsion in the $NN$ interaction, and also for the short-range correlations in nuclei. The suggested mechanism for the $\sigma$-dressing of the dibaryon is identical to that which explains the Roper resonance structure, its dominant decay modes and its extraordinary low mass. A similar transformation mechanism from the glue to the scalar field was discovered in $J/\Psi$ decays. The new experimental data on 2$\pi$-production in the scalar-isoscalar channel produced in $pn$- and $pd$-collisions and in particular the very recent data on $\gamma\gamma$ correlations in $p$C and $d$C scattering in the GeV region seems to corroborate the existence of the $\sigma$-dressed dibaryon in two- and three nucleon interactions.Comment: 14 pages,4 figure

Observation of the Hadronic Transitions Chi_{b 1,2}(2P) -> omega Upsilon(1S)

The CLEO Collaboration has observed the first hadronic transition among bottomonium (b bbar) states other than the dipion transitions among vector states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S) -> gamma omega Upsilon(1S) that is consistent with radiative decays Upsilon(3S) -> gamma chi_{b 1,2}(2P), followed by chi_{b 1,2} -> omega Upsilon(1S). The branching ratios we obtain are Br(chi_{b1} -> omega Upsilon(1S) = 1.63 (+0.35 -0.31) (+0.16 -0.15) % and Br(chi_{b2} -> omega Upsilon(1S) = 1.10 (+0.32 -0.28) (+0.11 - 0.10)%, in which the first error is statistical and the second is systematic.Comment: submitted to XXI Intern'l Symp on Lepton and Photon Interact'ns at High Energies, August 2003, Fermila

Методы лазерной спектроскопии в средствах непрерывного контроля содержания О2 и СО в дымовых газах котлов

Application efficiency of various absorption laser spectroscopy methods for determination of gas component concentration in boiler smoke gases has been studied in the paper, O2 and CO absorption spectra have been analyzed, optimum absorption lines in near IR spectral range (about 0.76 µm for O2 and 1.56 µm for CO) have been selected and graphical dependences of intensity and half-width of the selected lines on the investigated medium temperature and pressure have been shown. Processes of monitoring CO and O2 content in boiler smoke gases while using basic laser spectroscopy methods have been simulated and measuring errors have been analyzed. It has been found out that in order to decrease methodical errors of concentration measuring it is necessary to take into account the investigated medium temperature and pressure. The paper shows that the least errors of continuous CO and O2 concentration monitoring at the presence of variations in dissipative losses have been ensured by the modified correlation method though its threshold sensitivity is less than integral and correlation ones.Исследована эффективность применения различных методов абсорбционной лазерной спектроскопии для определения концентрации газовых компонент в дымовых газах котлов. Проанализированы спектры поглощения О2 и СО, выбраны оптимальные линии поглощения в ближней ИК области спектра (в районе 0,76 мкм для О2 и 1,56 мкм для СО) и приведены графические зависимости интенсивности выбранных линий и их полуширины от температуры контролируемой среды и давления в ней. Смоделированы процессы контроля содержания СО и О2 в дымовых газах котлов при использовании основных методов лазерной спектроскопии и проанализированы погрешности измерений. Выяснено, что для уменьшения методических погрешностей измерений концентрации необходимо учитывать температуру контролируемой среды и давление в ней. Показано, что наименьшие погрешности непрерывного контроля концентрации СО и О2 при наличии вариаций диссипативных потерь обеспечивает модифицированный корреляционный метод, хотя его пороговая чувствительность меньше, чем интегрального и корреляционного

In-Cell Biochemistry Using NMR Spectroscopy

Biochemistry and structural biology are undergoing a dramatic revolution. Until now, mostly in vitro techniques have been used to study subtle and complex biological processes under conditions usually remote from those existing in the cell. We developed a novel in-cell methodology to post-translationally modify interactor proteins and identify the amino acids that comprise the interaction surface of a target protein when bound to the post-translationally modified interactors. Modifying the interactor proteins causes structural changes that manifest themselves on the interacting surface of the target protein and these changes are monitored using in-cell NMR. We show how Ubiquitin interacts with phosphorylated and non-phosphorylated components of the receptor tyrosine kinase (RTK) endocytic sorting machinery: STAM2 (Signal-transducing adaptor molecule), Hrs (Hepatocyte growth factor regulated substrate) and the STAM2-Hrs heterodimer. Ubiquitin binding mediates the processivity of a large network of interactions required for proper functioning of the RTK sorting machinery. The results are consistent with a weakening of the network of interactions when the interactor proteins are phosphorylated. The methodology can be applied to any stable target molecule and may be extended to include other post-translational modifications such as ubiquitination or sumoylation, thus providing a long-awaited leap to high resolution in cell biochemistry