The evolutionary basis for differences between the immune systems of man, mouse, pig and ruminants

Studying the pathogenesis of an infectious disease like colibacillosis requires an understanding of the responses of target hosts to the organism both as a pathogen and as a commensal. The mucosal immune system constitutes the primary line of defence against luminal micro-organisms. The immunoglobulin-superfamily-based adaptive immune system evolved in the earliest jawed vertebrates, and the adaptive and innate immune system of humans, mice, pigs and ruminants co-evolved in common ancestors for approximately 300 million years. The divergence occurred only 100 mya and, as a consequence, most of the fundamental immunological mechanisms are very similar. However, since pressure on the immune system comes from rapidly evolving pathogens, immune systems must also evolve rapidly to maintain the ability of the host to survive and reproduce. As a consequence, there are a number of areas of detail where mammalian immune systems have diverged markedly from each other, such that results obtained in one species are not always immediately transferable to another. Thus, animal models of specific diseases need to be selected carefully, and the results interpreted with caution. Selection is made simpler where specific host species like cattle and pigs can be both target species and reservoirs for human disease, as in infections with Escherichia coli.

A Lateglacial archaeological site in the far north-west of Europe at Rubha Port an t-Seilich, Isle of Islay, western Scotland: Ahrensburgian-style artefacts, absolute dating and geoarchaeology

The exact pattern, process and timing of the human re-colonization of northern Europe after the end of the last Ice Age remain controversial. Recent research has provided increasingly early dates for at least pioneer explorations of latitudes above 54°N in many regions, yet the far north-west of the European landmass, Scotland, has remained an unexplained exception to this pattern. Although the recently described Hamburgian artefacts from Howburn and an assemblage belonging to the arch-backed point complex from Kilmelfort Cave have established at least a sporadic human presence during earlier stages of the Lateglacial Interstadial, we currently lack evidence for Younger Dryas/Greenland Stadial 1 (GS-1) activity other than rare stray finds that have been claimed to be of Ahrensburgian affiliation but are difficult to interpret in isolation. We here report the discovery of chipped stone artefacts with technological and typological characteristics similar to those of the continental Ahrensburgian at a locality in western Scotland. A preliminary analysis of associated tephra, pollen and phytoliths, along with microstratigraphic analysis, suggest the artefacts represent one or more episodes of human activity that fall within the second half of GS-1 and the Preboreal period

Climatology, storm morphologies, and environments of tornadoes in the British Isles: 1980–2012

A climatology is developed for tornadoes during 1980–2012 in the British Isles, defined in this article as England, Scotland, Wales, Northern Ireland, Republic of Ireland, Channel Islands, and the Isle of Man. The climatology includes parent storm type, interannual variability, annual and diurnal cycles, intensities, oc- currence of outbreaks (defined as three or more tornadoes in the same day), geographic distribution, and environmental conditions derived from proximity soundings of tornadoes. Tornado reports are from the Tornado and Storm Research Organization (TORRO). Over the 33 years, there were a mean of 34.3 tor- nadoes and 19.5 tornado days (number of days in which at least one tornado occurred) annually. Tornadoes and tornado outbreaks were most commonly produced from linear storms, defined as radar signatures at least 75 km long and approximately 3 times as long as wide. Most (78%) tornadoes occurred in England. The probability of a tornado within 10 km of a point was highest in the south, southeast, and west of England. On average, there were 2.5 tornado outbreaks every year. Where intensity was known, 95% of tornadoes were classified as F0 or F1 with the remainder classified as F2. There were no tornadoes rated F3 or greater during this time period. Tornadoes occurred throughout the year with a maximum from May through October. Finally, tornadoes tended to occur in low-CAPE, high-shear environments. Tornadoes in the British Isles were difficult to predict using only sounding-derived parameters because there were no clear thresholds between null, tornadic, outbreak, and significant tornado cases.

Fine structure of lamellated nerve endings in the gingiva of man and the Cebus apella monkey

Gingival mucosae of man and the adult Cebus apella monkey were fixed for 3 hr in modified Karnovsky fixative containing 2.5% glutaraldehyde, 2% formaldehyde in 0.1 M sodium phosphate buffer (pH=7.4). The specimens were postfixed in 1% osmium tetroxide in 0.1 M sodium phosphate buffer at 4°C for 2 hr, dehydrated in a graded alcohol series and embedded in Epon 812. Thick sections of 1-3 μm and ultrathin sections of 40-80 nm in thickness were cut with glass knives on an LKB ultramicrotome. The thick sections were stained with toluidine blue solution, and the grids were stained with uranyl acetate and lead citrate and examined under a Philips EM-301 electron microscope. Our observations permitted us to conclude that: both gingival mucosae, of man and the Cebus apella monkey, have lamellar nerve endings; these corpuscles are localized in the papillar space of the epithelium and do not contact closely with the basement membrane; the nerve endings are composed of an afferent fiber which subdivides several times and forms irregular flattened or discoidal expansions; the laminae of the lamellar cells are very thin near the terminal axon and are larger and irregular in shape at the peripheral portion of the corpuscle; the terminal axon shows abundant mitochondria, myelin figures, clear vesicles, and multivesicular bodies; between the axoplasm membrane and adjacent cytoplasmic lamina and between the lamellae, small desmosome type junctions are noted; and the cytoplasmic material of the lamellae cells is characterized by the presence of numerous microfilaments, microtubules, mitochondria, rough endoplasmic reticulum, and caveolae.

Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps): the role of man and fire

o reconstruct the vegetation and fire history of the Upper Engadine, two continuous sediment cores from Lej da Champfèr and Lej da San Murezzan (Upper Engadine Valley, southeastern Switzerland) were analysed for pollen, plant macrofossils, charcoal and kerogen. The chronologies of the cores are based on 38 radiocarbon dates. Pollen and macrofossil data suggest a rapid afforestation with Betula, Pinus sylvestris, Pinus cembra, and Larix decidua after the retreat of the glaciers from the lake catchments 11,000 cal years ago. This vegetation type persisted until ca. 7300 cal b.p. (5350 b.c.) when Picea replaced Pinus cembra. Pollen indicative of human impact suggests that in this high-mountain region of the central Alps strong anthropogenic activities began during the Early Bronze Age (3900 cal b.p., 1950 b.c.). Local human settlements led to vegetational changes, promoting the expansion of Larix decidua and Alnus viridis. In the case of Larix, continuing land use and especially grazing after fire led to the formation of Larix meadows. The expansion of Alnus viridis was directly induced by fire, as evidenced by time-series analysis. Subsequently, the process of forest conversion into open landscapes continued for millennia and reached its maximum at the end of the Middle Ages at around 500 cal b.p. (a.d. 1450).

The evolution of man: a popular exposition of the principal points of human ontogney phylogeny / From the German of Ernst Haeckel.

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The evolution of man: a popular exposition of the principal points of human ontogeny and phylogeny. From the German of Ernst Haeckel.

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The evolution of man: a popular exposition of the principal points of human ontogeny and phylogeny. From the German of Ernst Haeckel.

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The early history of man : with special reference to the Cap-Blanc skeleton / by Henry Field, Assistant Curator of Physical Anthropology.

no.26(1927)