Plant macrofossil evidence for an early onset of the Holocene summer thermal maximum in northernmost Europe.

Holocene summer temperature reconstructions from northern Europe based on sedimentary pollen records suggest an onset of peak summer warmth around 9,000 years ago. However, pollen-based temperature reconstructions are largely driven by changes in the proportions of tree taxa, and thus the early-Holocene warming signal may be delayed due to the geographical disequilibrium between climate and tree populations. Here we show that quantitative summer-temperature estimates in northern Europe based on macrofossils of aquatic plants are in many cases ca. 2 °C warmer in the early Holocene (11,700-7,500 years ago) than reconstructions based on pollen data. When the lag in potential tree establishment becomes imperceptible in the mid-Holocene (7,500 years ago), the reconstructed temperatures converge at all study sites. We demonstrate that aquatic plant macrofossil records can provide additional and informative insights into early-Holocene temperature evolution in northernmost Europe and suggest further validation of early post-glacial climate development based on multi-proxy data syntheses.

Why is it so difficult to simulate entropies, free energies, and their differences?

The classical 19th century thermodynamic inequalities of Clausius and Helmholtz are applied to the calculation of entropy and free energy changes by computer simulation. The irreversibility of finite-time thermodynamic paths is exploited to obtain upper and lower bounds on these quantities. Schrödinger's microscopic interpretation of heat and work provides the basis for a literal implementation of the key historical concepts on the computer using the Monte Carlo algorithm of Metropolis. Coupling schemes, paths, and reference states are variationally optimized to improve the convergence of the simulated properties, and a newly introduced variational flexibility, metric scaling, is overviewed. Reasons for expecting limiting power laws for the convergence are outlined.

[Restriction endonuclease analysis of Pomona serogroup of Leptospira interrogans].

Restriction Endonuclease Analysis (REA) was performed on DNAs from the type strains of the Pomona serogroup of Leptospira interrogans by using EcoRI and HhaI restriction enzyme, and the electrophoretic patterns obtained were compared with patterns obtained from 27 isolates from pig kidneys collected at abattoirs in Victoria, which belong to Pomona serogroup previous identified by MAT. All of the isolates were identified as serovar Pomona.

[Reference values for maximal midexpiratory flow in black females]. / Valeurs de référence pour le débit expiratoire maximal médian chez la femme noire.

The aim of this publication is to contribute to the establishment of reference values for the forced expiratory flow between 25 and 75% of the vital capacity (FEF25-75) among black females in West Africa. 316 of them, aged between 10 and 70 years, were submitted to this test. They were considered free from cardiopulmonary disease after a questionnaire and clinical examination. FEF25-75 in absolute value was lower than in the white Euro-americans. It increased up to 18-19 years of age, then decreased steadily thereafter. The main equations of regression for the FEF25-75 (l X s-1) were: 10-18 years, 0.177A + 1.058 and 0.157A + 0.826H + 0.005; 19-70 years, -0.028A + 4.211 and -0.025A + 2.206H + 0.512, (where A is the age in years and H the height in metres). The results are compared with the reference values published in Black Africa, Europe and the United States.

Transmissibility of two avian influenza a viruses (H7 N6) between chickens.

Differences were demonstrated in the transmissibility of two strains of avian influenza virus among chickens. One strain, A/duck/Victoria/76 (H7N6) spread quickly and infected all incontact chickens, whereas A/chicken/Victoria/75 (H7N6) spread slowly and failed to infect all incontact chickens. These strains were isolated in the same locality at about the same time in a region where the viruses, and the disease fowl plague, had not been previously recognised.