Diversity in coral reef fishes is not evenly distributed and tends to accumulate in the Indo-Malay-Philippines Archipelago (IMPA). The comprehension of the mechanisms that initiated this pattern is in its infancy despite its importance for the conservation of coral reefs. Considering the IMPA either as an area of overlap or a cradle of marine biodiversity, the hypotheses proposed to account for this pattern rely on extant knowledge about taxonomy and species range distribution. The recent large-scale use of standard molecular data (DNA barcoding), however, has revealed the importance of taking into account cryptic diversity when assessing tropical biodiversity. We DNA barcoded 2276 specimens belonging to 668 coral reef fish species through a collaborative effort conducted concomitantly in both Indian and Pacific oceans to appraise the importance of cryptic diversity in species with an Indo-Pacific distribution range. Of the 141 species sampled on each side of the IMPA, 62 presented no spatial structure whereas 67 exhibited divergent lineages on each side of the IMPA with K2P distances ranging between 1% and 12%, and 12 presented several lineages with K2P distances ranging between 3% and 22%. Thus, from this initial pool of 141 nominal species with Indo-Pacific distribution, 79 dissolved into 165 biological units among which 162 were found in a single ocean. This result is consistent with the view that the IMPA accumulates diversity as a consequence of its geological history, its location on the junction between the two main tropical oceans and the presence of a land bridge during glacial times in the IMPA that fostered allopatric divergence and secondary contacts between the Indian and Pacific oceans.
Absh.act--Two variations of a circular microstrip patch design are presented which excite very little surface wave power. Both of the proposed designs are based on the design principle that a ring of magnetic current in a substrate (which models the patches) will not excite the dominant TMo surface wave if the radius of the ring is a particular critical value. Numerical results for radiation efficiency and radiated field strength from a ring of magnetic current are shown to verify this basic design principle. The proposed patch designs are chosen to have a radius equal to this critical value, while maintaining resonance at the design frequency. These patch designs excite very little surfacewave power, and thus have smoother radiation patterns when mounted on finite-size ground planes, due to reduced surfacewave diffraction. These new patch designs also have reduced mutual coupling, due to the reduced surface-wave excitation. Measured results for radiation patterns and field strength within the substrate are presented to verify the theoretical concepts.
The most abundant and problematic metal compounds in crude oil exist as organic complexes of vanadium and nickel in porphyrin structures derived from biological molecules (chlorophyll and heme), the first petroleum biomarkers discovered by Alfred Treibs in the early 1930s. 1 Detailed characterization of the type and structure of porphyrins is critical for development of petroleum upgrading processes, but also to link crude oil to source rock conditions. Because petroporphyrins concentrate in heavy oils, direct characterization challenges routine analytical techniques due to the increased complexity associated with heavy crudes. Atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolving power (m/Δm 50% > 1 000 000 at m/z 500) and subppm mass error (<50 ppb) to identify nickel porphyrin isotopes for unambiguous elemental composition assignment. We also report the first simultaneous identification and categorization of both vanadyl and nickel porphyrins in the same sample, without prior sample preparation. More than 85 000 mass spectral peaks are resolved and identified in a single mass spectrum, and represent the most extensive molecular deconvolution of an organic mixture characterized to date.
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