WHAT'S SPACE GOT TO DO WITH IT? DISTANCE AND AGRICULTURAL PRODUCTIVITY BEFORE THE RAILWAY AGE

Owing to the high cost of transporting farm produce before the railway age, the land-intensiveness of European mixed farming caused both production and consumption of foodstuffs and intermediate farm inputs in the steady state to be highly dispersed, a spatial configuration offering weak inducement to reorganize farm structure or to invest available labour and capital with a view to increasing output. In such conditions the most common cause of rising agricultural productivity was spatial concentration of demand, which raised the demand price of farm produce and farm inputs within the privileged space bounded by discontinuities in the cost of land transport. The ultimate cause of observed changes in agricultural productivity before the nineteenth century must therefore be sought outside the farming sector in the development of markets for tradable manufactures, tradable services, and the economies of scale in their provision that supported spatial concentration of population.

WHAT'S SPACE GOT TO DO WITH IT? DISTANCE AND AGRICULTURAL PRODUCTIVITY BEFORE THE RAILWAY AGE

This paper argues that the conventional Malthusian account of pre-modern economies as constrained by diminishing returns resulting from a fixed land supplied is flawed because it does not recognize the importance of systematic indivisibilities in the production and distribution of farm produce that supported increasing return to additional inputs when the demand price of produce warranted them. Those indivisibilities locked in low-intensity farming practices in places where the demand for produce was diffuse. Most of pre-industrial Europe was in that situation, so average agricultural productivity was low. It was only in regions where urban concentrations of consumers aggregated demand to a level capable of inducing extra investment to exploit latent returns to scale in farming and transportation that the productivity of traditional mixed farming achieved its full potential.

FRENCH AGRICULTURE 1250-1550: CRISIS AND CONTINUITY

Between 1300 and 1500 the French agricultural economy was subjected to massive demographic, political, fiscal and monetary shocks. Despite these shocks, the seigniorial system of property rights governing the ownership and use of land remained largely unchanged. This paper describes the shocks and analyes the responses to them.

Molecular Studies on Bromovirus Capsid Protein II. Functional Analysis of the Amino-Terminal Arginine-Rich Motif and Its Role in Encapsidation, Movement, and Pathology

AbstractThe N-terminal region of the brome mosaic bromovirus (BMV) coat protein (CP) contains an arginine-rich motif that is conserved among plant and nonplant viruses and implicated in binding the RNA during encapsidation. To elucidate the functional significance of this conserved motif in the BMV CP, a series of deletions encompassing the arginine-rich motif was introduced into a biologically active clone of BMV RNA3, and their effect on replication, encapsidation, and infection in plants was examined. Analysis of infection phenotypes elicited onChenopodium quinoarevealed the importance of the first 19 N-proximal amino acids of BMV CP in encapsidation and pathogenicity. Inoculation ofC. quinoawith three viable variants of BMV RNA3 lacking the first 11, 14, and 18 N-terminal amino acids of the CP resulted in the development of necrotic local lesions and restricted the spread of infection to inoculated leaves. Progeny analysis from symptomatic leaves revealed that, in each case, virus accumulation was severely affected by the introduced mutations and each truncated CP differed in its ability to package genomic RNA. In contrast to these observations inC. quinoa,none of the CP variants was able to establish either local or systemic infections in barley plants. The intrinsic role played by the N-terminal arginine-rich motif of BMV CP in packaging viral RNAs and the interactions between the host and the truncated CPs in modulating symptom expression and movement are discussed

Maria Novella Borghetti, L’œuvre d’Ernest Labrousse. Genèse d’un modèle d’histoire économique

The historical writings of Ernest Labrousse constitute a central portion of the historical battleground invested by French historians between 1930 and 1960. Of the generals who led the valiant, but ultimately misguided attempt to construct a ‘total history’ of human experience, he was the least well-known outside the Hexagon. Outside the small world of specialists in eighteenth and early nineteenth-century French history, he was known in America and England mainly through David Landes’ critiq..

Maria Novella Borghetti, L’œuvre d’Ernest Labrousse. Genèse d’un modèle d’histoire économique

The historical writings of Ernest Labrousse constitute a central portion of the historical battleground invested by French historians between 1930 and 1960. Of the generals who led the valiant, but ultimately misguided attempt to construct a ‘total history’ of human experience, he was the least well-known outside the Hexagon. Outside the small world of specialists in eighteenth and early nineteenth-century French history, he was known in America and England mainly through David Landes’ critiq..

Handling qualities of a wide-body transport airplane utilizing Pitch Active Control Systems (PACS) for relaxed static stability application

Piloted simulation studies have been conducted to evaluate the effectiveness of two pitch active control systems (PACS) on the flying qualities of a wide-body transport airplane when operating at negative static margins. These two pitch active control systems consisted of a simple 'near-term' PACS and a more complex 'advanced' PACS. Eight different flight conditions, representing the entire flight envelope, were evaluated with emphasis on the cruise flight conditions. These studies were made utilizing the Langley Visual/Motion Simulator (VMS) which has six degrees of freedom. The simulation tests indicated that (1) the flying qualities of the baseline aircraft (PACS off) for the cruise and other high-speed flight conditions were unacceptable at center-of-gravity positions aft of the neutral static stability point; (2) within the linear static stability flight envelope, the near-term PACS provided acceptable flying qualities for static stabilty margins to -3 percent; and (3) with the advanced PACS operative, the flying qualities were demonstrated to be good (satisfactory to very acceptable) for static stabilty margins to -20 percent

Geology, geochemistry and Sr–Nd constraints of selected metavolcanic rocks from the eastern boundary of the Saharan Metacraton, southern Sudan : a possible revision of the eastern boundary

Neoproterozoic, Pan-African low-grade metavolcanic rocks and associated mafic and ultramafic rocks of ophiolitic origin have long been identified within the pre-Neoproterozoic Saharan Metacraton (SMC). These low-grade rocks within generally high-grade (upper amphibolite facies) gneiss and schist have not yet been fully investigated, and their geological and geotectonic significance have been recognised only in a very few localities: (1) the Delgo–Atmur ophiolite and low-grade volcano-sedimentary belt, (2) the Rahib ophiolite and low-grade sedimentary fold and thrust belt, both in northern Sudan along the eastern boundary of the Saharan Metacraton and (3) the low-grade volcano-sedimentary rocks in the Central African Republic. Dismembered and low-grade metamorphosed occurrences of mafic extrusive and intrusive and minor ultramafic rocks, grouped as the Arid unit, similar to those of the Arabian Nubian Shield (ANS), are reported here for the first time in the westernmost part of the Nuba Mountains, southeastern Sudan. These occurrences are interpreted to represent part of an ophiolite sequence with a lower cumulate layer composed of layered gabbro and minor cumulate hornblendite and a top layer of thick massive gabbro, pillowed basalt and basaltic andesite. The Arid unit is structurally underlain by basaltic-andesite and andesite and a metasedimentary sequence identified as turbidite and both grouped as the Abutulu unit. All of the rocks are slightly sheared, deformed and metamorphosed under low-grade greenschist facies to epidote amphibolite sub-facies. New geochemical and Sr–Nd isotope data reveal that the low-grade metavolcanic rocks of the westernmost Nuba Mountains represent a Neoproterozoic oceanic arc/backarc assemblage. The massive gabbro and pillowed basalt of the Arid unit show the geochemical characteristics of HFSE-depleted tholeiitic basalt while the co-genetic and more evolved meta-andesite of Abutulu unit show a calc-alkaline signature. Both units display a REE pattern characterized by LILE enrichment indicating formation in an arc/back-arc environment. This arc was active at around 778 ± 90 Ma (Sm– Nd 12 WR isochron) that is similar in age to the arc magmatism in the ANS. The close interval between the TDM Nd model age (average of 10 metavolcanic samples is 814 Ma) and the crystallization age (778 ± 90 Ma) is indicative of little or no involvement of older material. The western Nuba Mountains metavolcanic rocks have eNd values of +5.9 at 778 Ma (average of 12 samples) indicating a depleted mantle source similar to that of the ANS (published range from +6.5 to +8.4). The eNd values of the metavolcanic rocks are different from previously published ages of high-grade basement rocks that occupy the area west of the Kabus suture and east of Abutulu (+2.2 and +3.5 for the Rashad and Abbassyia). It is proposed that the metavolcanic and associated plutonic mafic rocks represent a unique Neoproterozoic entity named the Abutulu terrane that developed in a marginal back-arc basin west of the medium-grade gneiss of the Nuba Mountains. If the Abutulu terrane is included as a part of the ANS, then the eastern boundary of the SMC is adjacent to the western edge of the ANS along the Abutulu suture.http://www.elsevier.com/locate/precamres2017-08-31hb2016Geolog

Identification of a Forskolin-Like Molecule in Human Renal Cysts

Renal cyst enlargement is increased by adenosine cAMP, which is produced within mural epithelial cells. In a search for modulators of cAMP synthesis cyst fluids from 18 patients with autosomal dominant or recessive polycystic kidney disease (PKD) were analyzed, and in 15 of them, a stable lipophilic molecule that increased cAMP levels, stimulated transepithelial chloride and fluid secretion, and promoted the proliferation of human cyst epithelial cells was characterized. With the use of HPLC-mass spectrometry, a bioactive lipid with the same mass spectral fingerprint, the same chromatographic retention time, and the same biologic properties as forskolin, a widely known, potent adenylyl cyclase agonist, has been isolated and identified within the cyst fluid. Forskolin is synthesized by the plant Coleus forskohlii, but its appearance or compounds like it have not been reported in animals. The origin of forskolin in patients with PKD was not revealed by this study. Synthesis by mural cyst epithelial cells or an exogenous source are the most likely possibilities. Forskolin is sold for weight management and as a cardiovascular tonic in health stores and through the Worldwide Web. It is concluded that forskolin may have a role in promoting the enlargement of cysts in autosomal dominant PKD and recommended that patients avoid oral and parenteral preparations that contain this compound