A History of Depressed Skull Fractures from Ancient Times to 1800

The story of managing depressed fractures illustrates how knowledge of proven value does not always get handed down. Celsus was the first to describe sensible management for depressed fractures. As he wrote in Latin this was forgotten. Galen’s Greek writings survived forming the basis of management until the sixteenth century. In 1517, Hans von Gersdorff published a formidable illustrated surgical text. One illustration depicts an instrument for elevating depressed bone fragments. It looked dramatic but could not work and its defects were finally defined in the eighteenth century. Ambroise Paré used a bone punch just as we do today, but no later surgeon mentions this, though the instrument was well known. Elements of chance, fashion, emotionally powerful illustrations, and perhaps stubbornness had a profound effect on management delaying rational treatment for centuries.     

Do Manufacturing Firms Profit from Intraregional Innovation Linkages? An Empirical Based Answer

Nowadays, inter-firm linkages in the form of regional networks are seen as growth-promoting and important prerequisites for successful innovation activities in firms. Beginning with this hypothesis, the paper sets out to answer the question, whether manufacturing businesses with strong intraregional ties are more successful with respect to growth rates and innovative activities than those firms with little connection to their region. From a survey carried out in 10 European regions, the results verify that in spite of numerous network relationships on the national and international level small businesses are most likely to cooperate with others in their vicinity. In addition, the more knowledge-intensive innovation activities of businesses are, the more important is the relevance of spatial proximity in particular and networking in general.     

Changes in fluid pathways in a calcite vein mesh (Natih Formation,Oman Mountains): insights from stable isotopes

We present a structural, microstructural, and stable isotope study of a calcite vein mesh within the Cretaceous Natih Formation in the Oman Mountains to explore changes in fluid pathways during vein formation. Stage 1 veins form a mesh of steeply dipping crack‐seal extension veins confined to a 3.5‐m‐thick stratigraphic interval. Different strike orientations of Stage 1 veins show mutually crosscutting relationships. Stage 2 veins occur in the dilatant parts of a younger normal fault interpreted to penetrate the stratigraphy below. The δ¹⁸O composition of the host rock ranges from 21.8‰ to 23.7‰. The δ¹³C composition ranges from 1.5‰ to 2.3‰. This range is consistent with regionally developed diagenetic alteration at top of the Natih Formation. The δ¹⁸O composition of vein calcite varies from 22.5‰ to 26.2‰, whereas δ¹³C composition ranges from ?0.8‰ to 2.1‰. A first trend observed in Stage 1 veins involves a decrease of δ¹³C to compositions nearly 1.3‰ lower than the host rock, whereas δ¹⁸O remains constant. A second trend observed in Stage 2 calcite has δ¹⁸O values up to 3.3‰ higher than the host rock, whereas the δ¹³C composition is similar. Stable isotope data and microstructures indicate an episodic flow regime for both stages. During Stage 1, formation of a stratabound vein mesh involved bedding‐parallel flow, under near‐lithostatic fluid pressures. The ¹⁸O fluid composition was host rock‐buffered, whereas ¹³C composition was relatively depleted. This may reflect reaction of low ¹³C CO₂ derived by fluid interaction with organic matter in the limestones. Stage 2 vein formation is associated with fault‐controlled fluid flow accessing fluids in equilibrium with limestones about 50 m beneath. We highlight how evolution of effective stress states and the growth of faults influence the hydraulic connectivity in fracture networks and we demonstrate the value of stable isotopes in tracking changes in fluid pathways.     

Stable isotopic composition of chitin from arthropods recovered in archaeological contexts as palaeoenvironmental indicators

The effects of biodegradation and heating on the stable carbon, nitrogen, hydrogen and oxygen isotope ratios of chitin in arthropods were studied. Chitinous exoskeletons from seven aquatic arthropod species were subjected to anaerobic marine biodegradation in mud, to terrestrial biodegradation in soils, and to thermal degradation under anaerobic and aerobic conditions. The isotope ratios of chromatographically separated D-glucosamine hydrochloride and derivatives from treated and untreated specimens were then compared. Carbon, nitrogen, oxygen and hydrogen stable isotope ratios were all found to be conserved during partial degradation of chitin. Micromorphological comparative studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that no fungal chitin or other contaminants were present in the chitins that were chemically isolated from biodegraded substrates. Our results indicate that it will be possible to use stable isotope ratios of archaeological chitin samples for environmental and climatic reconstructions. An illustration of the utility of this approach comes from the observation that the stable isotope ratios of chitin from crustacean exoskeletons recovered from archaeological sites with ages up to 1400 years bp are in good agreement with measurements on modern crustaceans from similar environments.