Effect of reproductive toxicants on lipovitellin in female blue crabs, Callinectes sapidus

Changes in the concentration of lipovitellin, a lipoprotein that is the major protein in mature oocytes of crustaceans, were determined during ovarian development in female blue crabs, Callinectes sapidus. To test the effects of reproductive toxins on vitellogenesis, crabs were fed food containing cadmium or injected with the juvenile hormone antagonist, precocene II. Monoclonal antibodies prepared against one of the lipovitellin peptides (peptide A—107 kDa) were used in an enzyme linked immunosorbent assay to determine lipovitellin concentrations. Recently molted female crabs fed food containing cadmium (0.02 mg/g) for 18 days had oocytes with the same lipovitellin concentration as controls, but after 24 days the oocytes in cadmium treated crabs had significantly lower lipoprotein contents than controls (30 ± 4 ng/oocyte—cadmium treated; 45 ± 4 ng/oocyte—control). Precocene II-treated crabs had significantiy lower lipovitellin concentrations after 18 and 24 days. Diameters of oocytes were the same in both treated and control crabs. The results suggest that some pollutants may affect reproduction by acting during secondary vitellogenesis i.e., period when there is a large increase in lipovitellin synthesis. Since lipovitellins serve many of the nutritional needs of recently emerged crab embryos, poor larval survival may occur as a result of lower lipovitellin content.     

The role of organic matter in the sorption capacity of marine sediments

Past studies have suggested that desiccation enhances hydrophobicity of salt marsh sediment, and that drying and rewetting sediment can be used to investigate sorption mechanisms of amino acids and other organic compounds [Liu, Z., Lee, C., 2006. Drying effects on sorption capacity of coastal sediment: The importance of architecture and polarity of organic matter. Geochim. Cosmochim. Acta 70, 3313–3324]. Here we further develop this technique to study sorption of hydrophobic and hydrophilic organic compounds in a wide range of marine sediments. Our results show that hydrophilic compounds sorb strongly to wet coastal sediments; in dried sediments, sorption of hydrophilic compounds decreases, while sorption of hydrophobic compounds is greatly enhanced. Small compounds with aromatic rings sorb more in dried than wet coastal sediments, suggesting that aromatic groups have a stronger effect on sorption than polar groups like amino and carboxyl moieties. Sorption of lysine, glutamic acid and putrescine decreases greatly when sediment is pretreated with KCl, indicating the importance of cation ion exchange. However, α-amino acids sorb much more than corresponding β- or γ-amino acids, and l-alanine sorbs more than d-alanine, suggesting that amino group location and chiral selectivity play an important role in sorption. Comparison of lysine and tyrosine sorption in different sediments indicates that source and diagenetic state of organic matter are important factors determining sorption capacity. Lysine sorbs much more to organic detritus from salt marsh sediment than to fresh Spartina root materials, marine particles, lignin or humic acids, indicating the importance of structural integrity in sorption. Desorption hysteresis of glutamic acid, putrescine and lysine (in dried sediment) suggests the presence of enzyme-type sorption sites of high sorption energy or multiple binding mechanisms. Taken together, these findings suggest that organic matter plays the major role in amino acid sorption in organic-rich sediments.     

Ring current energy injection rate and solar wind-magnetosphere energy coupling

Assuming that the formation of the ring current belt is a direct consequence of an enhanced convection of plasma sheet protons, the expression for the energy injection rate U_R is formulated as a function of the cross-tail potential drop φ_CT for a simple electric field-magnetic field model. It is shown that an approximate expression for U_R thus formulated consists of two parts: (i) the first part U_R1, which is linearly proportional to φ_CT, is supplied by the corotation electric field and (ii) the second part U_R>2, which is proportional to φ²_CT, is supplied by the solar wind energy input to the magnetosphere. The second part U_R2 dominates the ring current energy input when the cross-tail potential drop φ_CT is greater than ～ 95 keV, namely during disturbed periods. An important finding is that the second part U_R2 of the ring current energy input is shown to be proportional to the solar wind-magnetosphere energy coupling function ?, recovering the observationally established relationship. Therefore, the present study verifies that an enhanced convection is the cause of the ring current formation.     

Time series surface-wave recovery from pressure gage

Recovery of surface-wave time series from pressure gage data is a time-consuming process and is not customarily carried out. Such information is, however, useful particularly in real-time for warning of freak waves or waves of unusual characteristics. Two simple numerical filters are developed here to serve such purpose. The first method is a linear filter with a built-in window to suppress high-frequency noise. The second method recovers the surface wave by computing the local surface curvature. These filters are very simple and can be programmed into a microprocessor to be integrated into field instrument packages.Both filters have been tested satisfactorily against conventional linear filters using simulated wave data and wave data collected in intermediate water depth. Neither filter requires pre-filtering of noise from raw data, which is commonly required to recover surface-wave information from sub-surface pressure data.     

Acute toxicity of heavy metals, tributyltin, ammonia and polycyclic aromatic hydrocarbons to benthic amphipodgrandidierella japonica

Benthic amphipod,Grandidierella japonica widely inhabits the Korean coastal waters and is developed as a standard test species for sediment toxicity tests. We exposedG . japonica to various pollutants including 4 kinds of inorganic metals (Ag, Cd, Cu and Hg), tributyltin [TBT], ammonia and 7 polycyclic aromatic hydrocarbon (PAH) compounds (acenaphthene, chrysene, fluoranthene, fluorene, naphthalene, phenanthrene and pyrene) to estimate the no observed effect concentration (NOEC) and the median lethal concentration (LC50) of each pollutant during the 96-hour acute exposure. Among all tested pollutants, TBT was most toxic toG. japonica, and Hg was most toxic among inorganic metals. The toxicity of pyrene toG. japonica was greatest among PAH compounds, followed by fluoranthene, phenanathrene, acenaphthene, fluorene and naphthalene. The toxicity of PAH compounds was closely related to their physico-chemical characteristics such as K_ow and water solubility.G. japonica responded adequately to pollutant concentrations and exposure durations, and the sensitivity ofG. japonica to various inorganic and organic pollutants was generally comparable to other amphipods used as standard test species in ecotoxicological studies, indicating this species can be applied in the assessment of environments polluted by various harmful substances.     

Effects of the Weak Polar Fields of Solar Cycle 23: Investigation Using OMNI for the STEREO Mission Period

The current solar cycle minimum seems to have unusual properties that appear to be related to weak solar polar magnetic fields. We investigate signatures of this unusual polar field in the ecliptic near-Earth interplanetary magnetic field (IMF) for the STEREO period of observations. Using 1 AU OMNI data, we find that for the current solar cycle declining phase to minimum period the peak of the distribution for the values of the ecliptic IMF magnitude is lower compared to a similar phase of the previous solar cycle. We investigate the sources of these weak fields. Our results suggest that they are related to the solar wind stream structure, which is enhanced by the weak polar fields. The direct role of the solar field is therefore complicated by this effect, which redistributes the solar magnetic flux at 1 AU nonuniformly at low to mid heliolatitudes.     

Boundary element modeling of multidirectional random waves in a harbor with partially reflecting boundaries

A numerical model is presented for the prediction of the wave field due to the diffraction of directional random waves in a harbor of arbitrary shape with partially reflecting boundaries. The water depth is assumed uniform and the method is based upon the superposition of diffraction solutions for monochromatic waves obtained by a two-dimensional boundary integral equation approach. The incident wave conditions are specified using a discrete form of the Mitsuyasu directional spectrum. The present numerical model has been validated through comparisons with previous experimental data and theoretical results for both regular and random wave diffraction by offshore breakwaters and in harbors. Good agreement was obtained in all cases. Based on these comparisons it is concluded that the present numerical model is an accurate and efficient tool to predict the wave field inside a harbor or around a breakwater in many practical applications.     

Geological interpretation of cone penetrometer tests in Norton Sound,Alaska

In situ cone-penetrometer tests at 11 stations in Norton Sound, Alaska, complement previous studies of geologic processes and provide geotechnical data for an analysis of sediment response to loading. Assessment of the penetrometer records shows that various geologic factors influence penetration resistance. On the Yukon prodelta, penetration resistance increases with the level of storm wave or ice loading. In central and eastern Norton Sound, thermogenic and biogenic gas, as well as variations in sediment texture and composition, effect a wide range of resistance to penetration.     

Origin of the metamorphosed clasts in the CV3 carbonaceous chondrite breccias of Graves Nunataks 06101, Vigarano,Roberts Massif 04143, and Yamato‐86009

We observed metamorphosed clasts in the CV3 chondrite breccias Graves Nunataks 06101, Vigarano, Roberts Massif 04143, and Yamato‐86009. These clasts are coarse‐grained polymineralic rocks composed of Ca‐bearing ferroan olivine (Fa_24–40, up to 0.6 wt% CaO), diopside (Fs_7–12Wo_44–50), plagioclase (An_52–75), Cr‐spinel (Cr/[Cr + Al] = 0.4, Fe/[Fe + Mg] = 0.7), sulfide and rare grains of Fe‐Ni metal, phosphate, and Ca‐poor pyroxene (Fs₂₄Wo₄). Most clasts have triple junctions between silicate grains. The rare earth element (REE) abundances are high in diopside (REE ~3.80–13.83 × CI) and plagioclase (Eu ~12.31–14.67 × CI) but are low in olivine (REE ~0.01–1.44 × CI) and spinel (REE ~0.25–0.49 × CI). These REE abundances are different from those of metamorphosed chondrites, primitive achondrites, and achondrites, suggesting that the clasts are not fragments of these meteorites. Similar mineralogical characteristics of the clasts with those in the Mokoia and Yamato‐86009 breccias (Jogo et al. 2012 ) suggest that the clasts observed in this study would also form inside the CV3 chondrite parent body. Thermal modeling suggests that in order to reach the metamorphosed temperatures of the clasts of >800 °C, the clast parent body should have accreted by ~2.5–2.6 Ma after CAIs formation. The consistency of the accretion age of the clast parent body and the CV3 chondrule formation age suggests that the clasts and CV3 chondrites could be originated from the same parent body with a peak temperature of 800–1100 °C. If the body has a peak temperature of >1100 °C, the accretion age of the body becomes older than the CV3 chondrule formation age and multiple CV3 parent bodies are likely.     

A period study and light-curve synthesis for the Algol-type semidetached binary XX Cephei

We obtained CCD photometric observations of the Algol-type semidetached binary XX Cephei (XX Cep) during 15 nights from 2002 September 17 to 2003 February 2, and also on 2005 January 21. Except for those data taken on the last night of the concentrated observing season, the 3881 measurements were obtained over an interval of only 106 nights. From these data, four new times of minimum light were calculated. The  (O− C)  diagram formed from all available timings, and thus the orbital period of the system, can be partly represented as a beat effect between two cyclical variations with different periods (      yr,      yr) and amplitudes  ( K ₁=0.015 d, K ₂=0.103 d)  , respectively. Both physical and non-physical interpretations of these cycles were investigated. The long-term sinusoidal variation is too long for magnetic cycling in solar-type single and close binary stars. In addition, we have studied the effect of a possible secular period variation. By analysing the residuals from our Wilson–Devinney (WD) binary model, we found small light variations with a period of 5.99 d with amplitudes growing toward longer wavelengths. We think that these oscillations may be produced by instabilities at the systemic L ₁ point (also occupied by the point of the cool star) and that these instabilities are, in turn, caused by non-uniform and sporadic convection. There is also a short-period oscillation of about 45 min in the WD light residuals that is attributed to accretion on to the mass-gaining primary component from a feeble gas stream originating on the cool donor star.