(Table 1) 87Sr/86Sr and Sr/Ca ratios in foraminiferal calcite from DSDP Holes 3-21 and 39-357

The 87Sr/86Sr ratio of ancient seawater, as recorded in marine carbonates, is an important tracer of long-term variations in ocean chemistry (Burke et al., 1982, doi:10.1130/0091-7613(1982)10<516:VOSSTP>2.0.CO;2; Peterman et al., 1970, doi:10.1016/0016-7037(70)90154-7; Dasch and Biscaye, 1971, doi:10.1016/0012-821X(71)90164-6; Veizer and Compston, 1974, doi:10.1016/0016-7037(74)90099-4; Brass, 1976, doi:10.1016/0016-7037(76)90025-9). However, the Sr isotope balance of the oceans has been difficult to constrain; consequently, attempts to evaluate the temporal 87Sr/86Sr changes have been largely qualitative. To constrain the causes of these variations we have measured 87Sr/86Sr ratios in carefully cleaned unrecrystallized foraminifera from DSDP sites 21 and 357. The data presented here have been quantitatively modelled taking advantage of recent advances in understanding of the Sr geochemical cycle. They suggest that whereas hydrothermal fluxes and carbonate recycling are of major importance in defining the marine 87Sr/86Sr ratio, the major control over its variations through the Cenozoic has been changes in the isotope composition of Sr derived from the weathering of silicate rocks.

What makes next generation members found their own firm: knowledge, contacts, or money?

To increase our understanding of the formation of students' intentions to found an own firm, research needs to systematically integrate theory of planned behavior, resource-based view, and family business literature. To date, however, an explicit and systematic integration of these perspectives cannot be found. We attempt to close this gap by explicitly investigating founding intentions of students with family business background. More specifically, we examine how the provision of human, social, and financial resources by the family affects students' desirability and feasibility perceptions, and ultimately founding intentions. Our analysis based on a sample of 14'290 students from 26 countries reveals that both desirability and feasibility perceptions mediate the relationships between all three types of resources and founding intentions. Interestingly, the provision of financial resources is negatively related to both desirability and feasibility perceptions. These findings illustrate the research potential of a combination of theory of planned behavior with the resource-based view, especially in the family business context. Our study thus offers valuable contributions to literature on career choices, theory of planned behavior, and family business, as well as to practice.

Cryo-EM structure of aerolysin variants reveals a novel protein fold and the pore-formation process

Owing to their pathogenical role and unique ability to exist both as soluble proteins and transmembrane complexes, pore-forming toxins (PFTs) have been a focus of microbiologists and structural biologists for decades. PFTs are generally secreted as water-soluble monomers and subsequently bind the membrane of target cells. Then, they assemble into circular oligomers, which undergo conformational changes that allow membrane insertion leading to pore formation and potentially cell death. Aerolysin, produced by the human pathogen Aeromonas hydrophila, is the founding member of a major PFT family found throughout all kingdoms of life. We report cryo-electron microscopy structures of three conformational intermediates and of the final aerolysin pore, jointly providing insight into the conformational changes that allow pore formation. Moreover, the structures reveal a protein fold consisting of two concentric β-barrels, tightly kept together by hydrophobic interactions. This fold suggests a basis for the prion-like ultrastability of aerolysin pore and its stoichiometry.

Webster and Dexter Township (Mich.) residences, ca. 1874

Left to right: Res. of Samuel H. Ball, Sec 5, Webster Tp. Mich.; Res. of Alexander Mallion, Sec 28, Wester Tp., Mich.; Res. of J.B. Arms, Sec 4, Webster Tp. Mich.; Res. of Frederick Lee, Sec 30, Webster Tp. Mich.; Res. of Patrick Fleming, Sec 25, Dexter Tp. Mich.; Res. of W.. Brass, Sec 31, Webster Tp. Mich. Publication information: Chicago, Ill. : Everts & Stewart, 1874.

The art of cutting, casting, and preparing of letter for printing.

Mode of access: Internet.

A treatise on brasses, bronzes, and other alloys : and their constituent metals /

Includes bibliographical references.

Feierlicher Einzug : für 12 Trompeten, 3 Solotrompeten, 4 Hörner, 4 Posaunen, 2 Tuben und Pauken /

Mode of access: Internet.

Legende : Quartett für vier Hörner in F /

Caption title.

British manufactures.

[Vols. 4-6] are called "Series IV-VI."

Writing Table

Anonymous, English, 18C; 2 ft. 11 7/16 in. x 5 ft. 3 3/16 in. x 2 ft. 4 47/64 in.; mahogany and padouk, brass and gilt bronze