Shake & Bake: Dual-Use Chemicals, Contexts, and the Illegality of American White Phosphorus Attacks in Iraq

[Excerpt] “On November 29, 2005, in a Department of Defense press conference with Secretary of Defense Donald Rumsfeld and Gen. Peter Pace, Chairman of the Joint Chiefs of Staff, General Pace stated that white phosphorus “is a legitimate tool of the military,” and can be used for illumination, smoke, and incendiary purposes. Incredibly, the Department of Defense released an addendum to the press conference clarifying that white phosphorus was not used as an incendiary weapon. According to General Pace, “it was well within the law of war to use white phosphorus . . . for marking and screening.” This was the last official statement on white phosphorus. The chemical’s legality as an anti-personnel weapon within the laws of war or the Chemical Weapons Convention was not discussed. Despite the Pentagon’s claim that white phosphorus has only been used for legitimate purposes (illumination and smoke) in Iraq, there have been numerous allegations and accounts by members of the U.S. military, war correspondents, and Iraqi civilians that white phosphorus has been used as an anti-personnel weapon against Iraqi combatants and civilians within urban areas. This note examines: (1) “Shake & Bake”: the use of white phosphorus to flush out combatants from fortified positions so they can be killed with conventional munitions; (2) the direct use of white phosphorus illumination mortars against human targets; and (3) the use of improvised phosphorus bombs to clear insurgents out of buildings. White phosphorus is an example of a “dual-use” chemical. As with most dual-use chemicals, there are lawful and prohibited purposes. It is an especially legally precarious chemical because there are both legitimate and potentially improper military purposes. Peter Kaiser, spokesman for the Organization for the Prohibition of Chemical Weapons (OPCW) (the international body responsible for implementation of the Chemical Weapons Convention) has described the prohibited uses of white phosphorus as those military purposes that are dependent on the chemical’s toxicity. Thus, the central question of this article asks whether the legality of the United States’ intended use of anti-personnel white phosphorus depends on the chemical’s toxic properties. This note analyzes the legal implications of the cited examples of white phosphorus use by looking at the following: (1) general principles of international humanitarian law and the necessity defense, (2) the Zyklon B case, and (3) the Chemical Weapons Convention and the Chemical Weapons Convention Implementation Act of 1998.

Water retention properties of the clay in soils developed on clayey sediments: significance of parent material and soil history

International audienceWe have investigated the water retention properties of clayey subsoil horizons according to the variation of clay characteristics. The horizons studied developed on a large range of age and facies of calcareous or calcium-saturated clayey sediments. The water retention properties were studied from −10 hPa to −15 000 hPa water potential using small clods collected in winter when swelling is at a maximum and water content close to field capacity. The specific water content and volume of the clods at field conditions, their specific volume at −15 000 hPa water potential, the clay content, the organic carbon content, the cation exchange capacity, the N2-BET surface area and calcareous content were measured. The clay fabric, which is the spatial distribution of the elementary clay particles, was quantified when the soil was close to field capacity and we could attribute the whole pore volume to the porosity of the clay fabric. Our results show that the water retention properties of the clay vary greatly from one soil to another with respect to the clay fabric. The variation of the latter depends on the cation exchange capacity, the size of elementary particles and hydric stress history of the clay. We show that the water retention properties of the studied clayey soils vary according to the clay content and fabric, the latter being related either to parent material fabric or to both the hydric history of the soil and size of the elementary clay particles

Le sol, lieu d'échange et de transferts. Conséquences de leur utilisation par l'homme : un exemple français

Les sols exercent une multiplicité de fonctions de régulation entre l'atmosphère et les milieux aquatiques. Ceci est lié à leurs caractéristiques très variables dans l'espace, à la diversité des processus de nature physique, physico-chimique et biologique qui s'y déroulent, mais aussi à leur position d'interface entre l'atmosphère, le substrat géologique et les milieux aquatiques. Les échelles de temps qui président à sa genèse sont en général longues, du millier d'années au million d'années. Il s'agit donc d'une ressource non renouvelable à l'échelle humaine.Les changements dans les pratiques agricoles ont profondément modifié le cycle de l'eau. Ainsi la perte de matières organiques des sols tend à amplifier l'encroûtement de surface et le ruissellement et conduit à une érosion importante des terres. Les prélèvements des cultures étant plus importants, la reconstitution de la réserve en eau des sols est souvent problématique les années sèches.La science du sol doit fournir une réserve de connaissances dans laquelle la recherche appliquée puise des éléments d'interprétation de leur fonctionnement, et ce, afin de répondre aux besoins de l'agriculture et de l'environnement. Le sol doit alors être considéré comme un écosystème qui lui-même est une composante d'un écosystème plus vaste. Son étude nécessite de considérer une très large gamme d'échelles spatiales et d'échelles temporelles. Les évolutions des sols sont lentes et difficiles à déceler aisément. Les études sont donc complexes et nécessitent la durée. Elles permettent in fine d'évaluer les altérations possibles de ses diverses fonctions avec une estimation des risques résultant de cette altération. Ceci démontre qu'il convient de réévaluer le sol par rapport à ses fonctions environnementales, donc en ne se limitant pas à la seule fonction de production.Soils perform a large variety of functions involved in regulation of biogeochemical fluxes between the atmosphere and the aquatic environment. Soil characteristics show significant variation spatially, in the diversity of physical, physico-chemical and biological processes. Soils also vary with respect to their location as an interface with the atmosphere, the geological substrate and aquatic environments. The time-scales governing the formation of soils are generally long, ranging from a thousands to millions of years and therefore, they are not a renewable resource from the human perspective.The functions involved in soil regulation can be modified by various forms of stress related to farming, industrial and urban activities. In soil management, the catchment slope or watershed represents the most appropriate spatial scale for the assessment and understanding of soil distribution.. Throughout history, soil use has changed drastically depending on different environmental constraints, the available technology and the requirements of the human population. In order to manage soil, it is necessary to acquire a complete understanding of the conditions under which it has been formed. The chemical evolution of soils is related to natural processes. For example, in temperate regions, the main factor dictating soil evolution is the gradual loss of cations. These reductions in cations affect soil carbonates, which are gradually dissolved. Following the dissolution of soil carbonates, there are changes in levels of exchangeable cations, initially with the calcium found on the surface of the soil components (clay, organic matter and oxides). The soil then becomes acidic, and when the acidity becomes sufficiently low, the mineral components of the soil can be partially dissolved. Free aluminum can therefore be present in the soil and water, thus creating toxic conditions for plants (cultivated soils, forests) and to fish (pond water and river water).Changes in soil use and the introduction of new practices often have a considerable impact on soil components and soil properties. In the soils of France today, the carbon and nitrogen balances are generally negative. This results in a widespread reduction in the levels of organic matter. Cultivated soils generally imply CO2 emission into the atmosphere, often related to grassland cultivation and to other intensive farming practices (Arrouays et al. 1994; Rivière, 1999). Measuring and modeling the environmental balance therefore represents a major challenge both with respect to the protection of the soil environment and also with respect to understanding the global cycle of greenhouse gases such as nitrogen and carbon compounds.The presence of contaminants and the study of their bioavailability also represent major challenges in soil research. Certain parent rocks contain a appreciable quantities of potentially toxic trace elements (Pb, Cd, Ni, Co, Cu, Zn, As). The continuous supply of substances containing pollutants results in greater inflows of trace elements than outflows. In France, there are an estimated 36,000 t/yr of copper applied to French vineyards. Regions with intensive indoor husbandry, such as Brittany, are also concerned with the addition of copper and zinc in animal diets. The supply of phosphates as fertilizers has also been a source of cadmium pollution. Urban waste is also a recent source of pollution, and the effects of air-based pollution around industrial zones needs to be taken into consideration.Human activity affects not only the storage and transfer of water and dissolved elements, but also the aeration and temperature conditions that could impact biological activity. Although the organization of solid particles and pores is partially a result of conditions under which the soil has been formed, human activity both directly (cultivation methods, soil drainage) and indirectly (influence of plant and fauna activity) influences the physical properties of soil. For example, the general trend is for the organic matter content to decrease with an increase in soil use (ploughing of grassland). This is particularly true in the case of silty soils, which contain small quantities of clay and are thus less stable structurally and are susceptible to physical erosion. Soil chemistry also affects physical properties. For example, under slightly acidic conditions, soil particles can become highly mobile in the environment. The migration of clay from the upper soil layers to the lower layers (translocation) should not be ignored. This relative loss of clay from the surface can be observed over time as the soil becomes particularly sensitive to the effects of water (incrustation, particle suspension) and, finally, erosion and run-off occur.Soil science must provide a reservoir of knowledge in order to increase the understanding of soil functions and to meet the needs of agriculture and the environment. The study of soil must incorporate both spatial and temporal trends, as changes are often slow and difficult to detect. This demonstrates the need to reassess soil with respect to its environmental functions, without limiting the assessment to merely the function of production

Rôle des conditions pédoclimatiques sur la présence d'une savane en milieu forestier tropical africain : cas de la savane de Dabou (Côte-d'Ivoire)

La région de Dabou a longtemps été caractérisée par la présence d'une savane, végétation inhabituelle dans cette zone subéquatoriale humide à forêt sempervirente. Les études réalisées dernièrement montrent que cette région se distingue non seulement par sa végétation, mais également par une organisation de la couverture pédologique en rapport avec un paysage (modelé, réseau hydrographique) caractéristique de zones plus sèches. Le facteur permettant d'expliquer le maintien de la savane jusqu'à une époque récente est avant tout d'ordre pédoclimatique. (Résumé d'auteur

Optimal classical-communication-assisted local model of n-qubit Greenberger-Horne-Zeilinger correlations

We present a model, motivated by the criterion of reality put forward by Einstein, Podolsky, and Rosen and supplemented by classical communication, which correctly reproduces the quantum-mechanical predictions for measurements of all products of Pauli operators on an n-qubit GHZ state (or ``cat state''). The n-2 bits employed by our model are shown to be optimal for the allowed set of measurements, demonstrating that the required communication overhead scales linearly with n. We formulate a connection between the generation of the local values utilized by our model and the stabilizer formalism, which leads us to conjecture that a generalization of this method will shed light on the content of the Gottesman-Knill theorem.Comment: New version - expanded and revised to address referee comment

Influence du pH sur les propriétés des sols : l'essai de longue durée des 42 parcelles à Versailles

Les pratiques de fertilisation et d'amendement peuvent contribuer à modifier profondément les propriétés des sols. Ceci est mis en évidence par le dispositif des 42 parcelles de l'INRA à Versailles qui reçoit chaque année les mêmes traitements depuis 1929. Il présente l'originalité d'être en jachère nue. Les résultats reportés ici reposent sur 16 traitements que nous comparons à une parcelle témoin. Le sol est à caractère limoneux avec 14 à 22 % d'argile. Le pH, la capacité d'échange au pH du sol (CECsol), et les cations échangeables ont été mesurés. Des mesures de porosité, de rétention de l'eau à différents potentiels de l'eau ont été effectuées.Des variations considérables de pH sont observées. Les engrais ammoniacaux conduisent à des parcelles très acides (pH 3,5 à 5,0), à faible CECsol, essentiellement saturée par des cations aluminium. Dans les parcelles chaulées ou recevant des amendements basiques, le pH est tamponné à 8,2 par les carbonates. La CECsol double du sol acide au sol chaulé où elle est majoritairement saturée par du calcium échangeable. Avec les sels neutres (par exemple KCl, NaNO3) le pH n'a pas changé et pour le témoin il a légèrement baissé. Des observations de terrain montrent que ces différents états physico-chimiques sont en relation avec les états de surface du sol et influencent la porosité du sol en profondeur.Ainsi dans les sols des régions tempérées la CECsol peut doubler dans un domaine très restreint de pH (6,0 à 7,5), orientant fortement les propriétés physiques des sols.In temperate regions, soil acidification is a real problem. The pH change causes transformations of both the chemical and physical properties of the soil. The 42 experimental plots at the Institut national de Recherche agronomique (INRA) in Versailles, France, were created in 1929. Since that time, each plot has received either fertiliser or amendments (Table 1). There are ten reference plots that have not been treated. Plots were dug up twice a year and left fallow. The results corresponding to 17 plots, 16 treated and one reference plot, are presented in this paper. The samples were collected in 1999 and compared to the 1929 soil reference. The pH was measured in water (AFNOR 1994), the cation exchange capacity (CEC) was determined at pH 7.0 (AFNOR 1994, CEC7) and at the soil pH by the cobaltihexamine method (Ciesielski and Steckermann 1997, CECsoil). Exchangeable cations (Ca2+, Mg2+, K+ and Na+) were measured after cobaltihexamine extraction and exchangeable aluminium by the KCl method (McLean, 1965). Water retention measurements were carried out with an apparatus developed by Tessier and Berrier (1979) and AFNOR (1996) at -10 kPa, with the Richards pressure plate cell at -1.6 kPa (Richards 1948) and with a controlled hygrometry dessicator at -107 MPa (Tessier 1984).The average pH of the reference plot collected in 1929 was close to 6.3. In 1999, pH values ranged between 3.5 and 8.2. For plots treated with ammonium fertilisers the pH ranged from 3.5 to 5.5. In contrast, plots with basic treatment or liming had a soil pH that was close to 8.2 and was equilibrated with carbonates. Intermediate pH values (from 5.5 to 7.5) were obtained for plots treated with neutral salts such as KCl or NaNO3, or with superphosphate.The cation exchange capacity in soils at the reference pH (7.0) demonstrated variations in soil composition. For example, the CEC7 varied with clay content as a function of depth or with organic matter loss or gain due to lying fallow or to manure application. When the CEC was measured at soil pH (CECsoil), strong differences were observed. Two groups of plots can be differentiated in 1999. One ranged between 11 and 16 cmol+/kg; this range corresponded to plots with amendments or with fertilisers containing bases. A lower range of CECsoil values (below 11 cmol+ /kg) was obtained with ammonium fertilisers. It is important to note that between pH=6.0 and pH=7.5 the CECsoil doubled.Six months after digging, the surface state of the soil was variable. Thick crusts dominated in acidic conditions, whereas the presence of dispersing cations (K+, Na+), and a smooth surface was present in soil treated with amendments. In the soil profile, bulk density increased with acidity and sodium or potassium cation concentrations. At -10 kPa, water retention measurements demonstrated that bulk density and sampling depth were linked with water retention: the higher the bulk density, the lower the water retention. At -1.6 MPa, water retention was correlated to the amount of clay and organic matter content. We also showed that the exchangeable calcium content and CECsoil influence water retention. At -107 MPa, water retention depends on pH as well as the CECsoil and exchangeable cation concentration.The main purpose of this study was to show that after 70 years, plots subjected to intensive fertilisation or amendments and lying fallow (i.e., without organic matter restitution), have dramatically different soil properties. The first indicator of this evolution was pH. Ammonium fertilisers produced very acid plots (pH 3.5 to 5.0). In the presence of neutral salts (e.g., KCl, NaNO3) and in the reference plot, the pH had decreased a little. In liming or basic treatment plots, the pH is controlled at 8.2 by carbonates. The second important factor to consider is the cation exchange capacity value. When measured at a reference pH (pH=7.0), the CEC7 reflects the natural components present in a soil, but doesn't consider the influence of physico-chemical factors that operate in the native soil. After 70 years without organic restitution, the soil has lost approximately half of its original organic matter content, and as a result the exchangeable sites were approximately 2 cmol+ /kg.The effective CEC at soil pH demonstrates the influence of pH on variable charges due to mineral constituents and organic matter. Plots with ammonium fertilisers have a low cation exchange capacity. Fertilisers with sodium and potassium cations have increased the exchangeable sodium (up to 11% of the CECsoil) or potassium (18%) respectively. The cation exchange capacity doubled in going from acidic plots to liming plots, and in the latter the CEC is mainly saturated with exchangeable calcium.In situ plot observations show that soil physico-chemical properties strongly influence not only soil surface state, but also soil profile porosity. Both acidification and dispersing cations are factors in soil degradation, whereas high pH values and calcium as the exchangeable cation produce strong structure stability and high porosity. It is also interesting to note that the CECsoil can double between pH=6.0 and pH=7.5, thus influencing the physical properties of the soil. Comparing CEC7 and CECsoil facilitates the prediction of the effects of fertilisation and amendments on soil properties. The cation exchange capacity at soil pH can be used as an excellent indicator of soil quality

Évolution de la concentration en protozoaires et en ammoniaque de fermentations ruminales avec un substrat supplémenté en extraits de plantes à saponines

Yucca schidigera et Quillaja saponaria sont des plantes à saponines (PAS) utilisées en alimentation des ruminants pour optimiser la gestion de l’ammoniaque (NH3) dans le rumen, en particulier lorsque les rations sont riches en azote soluble (e.g. mise à l’herbe, manque d’énergie). Les données sur d’autres PAS sont rares bien que ces métabolites secondaires amphiphiles sont présentes dans beaucoup de végétaux. L’objectif de ce travail était de déterminer in vitro l’effet d’extraits de plantes à saponines sur l’évolution du nombre de protozoaires et sur la concentration en NH3 du fluide ruminal

Entanglement of Dirac fields in non-inertial frames

We analyze the entanglement between two modes of a free Dirac field as seen by two relatively accelerated parties. The entanglement is degraded by the Unruh effect and asymptotically reaches a non-vanishing minimum value in the infinite acceleration limit. This means that the state always remains entangled to a degree and can be used in quantum information tasks, such as teleportation, between parties in relative uniform acceleration. We analyze our results from the point of view afforded by the phenomenon of entanglement sharing and in terms of recent results in the area of multi-qubit complementarity.Comment: 15 pages, with 8 figures (Mar 2006); accepted to Physical Review A, July 2006 - slightly revise