Search

During 2018 and 2019, the Mars Science Laboratory Curiosity rover investigated the chemistry, morphology, and stratigraphy of Vera Rubin ridge (VRR). Using orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars, scientists attributed the strong 860 nm signal associated with VRR to the presence of red crystalline hematite. However, Mastcam multispectral data and CheMin X‐ray diffraction (XRD) measurements show that the depth of the 860 nm absorption is negatively correlated with the abundance of red crystalline hematite, suggesting that other mineralogical or physical parameters are also controlling the 860 nm absorption. Here, we examine Mastcam and ChemCam passive reflectance spectra from VRR and other locations to link the depth, position, and presence or absence of iron‐related mineralogic absorption features to the XRD‐derived rock mineralogy. Correlating CheMin mineralogy to spectral parameters showed that the ~860 nm absorption has a strong positive correlation with the abundance of ferric phyllosilicates. New laboratory reflectance measurements of powdered mineral mixtures can reproduce trends found in Gale crater. We hypothesize that variations in the 860 nm absorption feature in Mastcam and ChemCam observations of VRR materials are a result of three factors: (1) variations in ferric phyllosilicate abundance due to its ~800–1,000 nm absorption; (2) variations in clinopyroxene abundance because of its band maximum at ~860 nm; and (3) the presence of red crystalline hematite because of its absorption centered at 860 nm. We also show that relatively small changes in Ca‐sulfate abundance is one potential cause of the erosional resistance and geomorphic expression of VRR., Key Points Hematite likely controls the wavelength position of the ~860 nm absorption in Mastcam multispectral observations of drill targetsLab results show that the ~860 nm band depth increases with ferric phyllosilicate abundance due to its ~800–1,000 nm featureThe reflectance maximum near 860 nm in pyroxene affects the ~860 nm band depth in spectra of lab mixtures and drilled rocks on Mars

Agricultural economics is sometimes criticised for being microcentred. We should not apologise; colleagues who study industrial organisation or many aspects of public sector economics are neither more nor less guilty. The fact remains, however, that agriculture, like all sectors, operates within a macro-economic framework and there is a growing spate of literature focusing on that broader perspective. It runs in two directions: the farming consequences of macro-economic developments where much of the attention focuses on exchange rates and interest rates, and the effects of agricultural policies on the economy at large. The objective here is to review the situation. Topical issues considered range from the value of the dollar and the operation of the European exchange-rate, mechanism, to controversies surrounding the recent GATT negotiations.

Unternehmenskrisen sind kein alltagliches, aber ein hilfreiches und haufig letztes Signal zur Umkehr („krisis“ aus dem griechischen = Umschwung eines bisher gleichmasigen Ablaufs). Sie kommen nicht aus heiterem Himmel, sondern ziehen meist wie ein Gewitter am Horizont auf und nehmen dann direkten Kurs auf einen zu. Noch hat das Unternehmen die Chance, Vorbereitungen zu treffen und sich auf die Sturmfahrt vorzubereiten. In dieser Gefahrensituation ist der Teamgeist „all hands on deck“ und ein gemeinsames Ziehen an einem Strang unerlasslich, um schwere Schaden von Unternehmen und Mannschaft abzuwenden. Die Krise als Chance zu begreifen, die Mannschaft zusammen zu schweisen und die Motivation und den Elan in dieser ausergewohnlichen Situation zu nutzen, um das Ruder herum zu reisen, erfordert viel Erfahrung, Geschick und Besonnenheit. Insbesondere der Umgang mit den ohnehin hochsensiblen, hochvolatilen und psychologisch extrem anfalligen Kapitalmarkten bedingt einen taktisch und operativ klar durchdachten Kommunikationsplan der Investor Relations, um nicht das Manover des letzten Augenblicks einleiten zu mussen.

Sowing Modernity: America's First Agricultural Revolution. By Peter D. McClelland. Ithaca and London: Cornell University Press, 1997. Pp. xii, 348. $45.00. ISBN 0–8014–3326–6. JEL 98–0723

Following a study tour of China a brief account is presented of recent changes in agricultural policy with some short comments on living conditions. The account concentrates on the prominence now given to agriculture within the planning process and the recent raising of its status relative to other sectors. This is associated with the change to the household responsibility system allied to upward adjustment in agricultural producer prices and some adjustment in input costs.

(1982). A century of land values 1781–1880. Oxford Agrarian Studies: Vol. 11, No. 1, pp. 93-107.

Changes in capital taxation in Britain have recently provoked controversy. There has been wide ranging discussion of the role and rationale of capital taxation within the economy at large and much has been written about its specific effects in agriculture. These hues are reviewed in the paper. It also contains information on the wealth position of farmers and considers the impact of capital transfer tax upon them. Though there may be some cause for concern as a result of recent events the case for providing further concessions to agriculture is discounted. Resume CERTAINES THESES SUR L'IMPOSITION DU CAPITAL Les changements recents survenus en Grande-Bretagne dans l'imposition du capital soulevent des controverses. TreS nombreuses ont ete les theses developpees autour du role et de la logique de l'imposition du capital dans l'economie prise dans son ensemble et tres dense est le volume des articles qui traitent de ses effets specifiques sur l'agriculture. Tous ces arguments et analyses sont passes en revue dans le preent article, qui apporte aussi une information sur la situation des agriculteurs en matiere de richesses et examine les repercussions exactes sur leurs avoirs et revenus de l'imposition des transferts ou cessions d'exploitations. Selon les conclusions de l'auteur, bien que l'evolution recente dans ce domaine puisse donner lieu e une certaine inquietude, aucun argument suffisamment solide ne peut ětre invoque dans le sens de concessions supplementaires a l'agriculture. Zusammenfassung EINIGE UBERLEGUNGEN ZUR KAPITALBESTEUERUNG Veranderungen der Kapitalbesteuerung in Groβritannien haben kurzlich eine Kontroverse ausgelost. Die Bedeutung und der Sinn der Kapitalbesteuerung innerhalb der Volkswirtschaft als ganzes sind ausgiebig diskutiert worden, und es ist viel uber ihren spezifischen Effekt auf die Landwirtschaft geschrieben worden. Diese Ergebnisse werden in diesem Artikel untersucht. Auβerdem informiert der Artikel uber die Wohlstandssituation der Farmer und betrachtet die Auswirkung der Kapital-ubertragungssteuer fur sie. Obwohl es infolge kurzlicher Ereignisse einigen Grund zur Besorgnis geben mag, wird das Anliegen, der landwirtschaft weitere Konzessionen zusugestehen, verworfen.

Since the ending of World War II increasing attention has been paid in Britain to the need for the formulation of a coherent land use planning strategy. Public control over land use has strengthened and interest in the conceptual and practical problems involved has grown to a sufficient extent to have generated a significant body of literature. This article begins with a short account of the land use planning process, considers the state of land use statistics and outlines the results of work by a number of writers on projections of land requirements in various uses notably for agriculture, forestry and urban expansion. Against this background attention then focuses on the use of cost-benefit analysis as a means of resolving conflicts in land allocation, particularly those which centre on agricultural use as against urban expansion, and agriculture versus forestry development. A further section considers the application of cost-benefit methods in research on recreational uses of land. The paper is designed primarily as a critical survey of the present state of knowledge, though it also indicates areas of study in which the expertise of the agricultural economist might be particularly useful.

The Serpell Report on British Rail was greeted by hysteria from the Opposition benches and an apparently vote-catching cold shoulder from Mr Howell and his Cabinet colleagues. But Serpell's opponents have failed to demonstrate that the supposed benefits of under-used railway lines are worth their enormous costs, both in money and in opportunities and innovations foregone.

n/a

n/a