Sharp gene pool transition in a population affected by phenotype-based selective hunting

We use a microscopic model of population dynamics, a modified version of the well known Penna model, to study some aspects of microevolution. This research is motivated by recent reports on the effect of selective hunting on the gene pool of bighorn sheep living in the Ram Mountain region, in Canada. Our model finds a sharp transition in the structure of the gene pool as some threshold for the number of animals hunted is reached.Comment: 5 pages, 4 figure

The Poopó Polymetallic Epithermal Deposit, Bolivia: Mineralogy, Genetic Constraints, and Distribution of Critical Elements

The tin-rich polymetallic epithermal deposit of Poopó, of plausible Late Miocene age, is part of the Bolivian Tin Belt. As an epithermal low sulfidation mineralisation, it represents a typological end-member within the "family" of Bolivian tin deposits. The emplacement of the mineralisation was controlled by the regional fault zone that constitutes the geological border between the Bolivian Altiplano and the Eastern Andes Cordillera. In addition to Sn and Ag, its economic interest resides in its potential in critical elements as In, Ga and Ge. This paper provides the first systematic characterisation of the complex mineralogy and mineral chemistry of the Poopó deposit with the twofold aim of identifying the mineral carriers of critical elements and endeavouring to ascertain plausible metallogenic processes for the formation of this deposit, by means of a multi-methodological approach. The poor development of hydrothermal alteration assemblage, the abundance of sulphosalts and the replacement of löllingite and pyrrhotite by arsenopyrite and pyrite, respectively, indicate that this deposit is ascribed to the low-sulphidation subtype of epithermal deposits, with excursions into higher states of sulphidation. Additionally, the occurrence of pyrophyllite and topaz has been interpreted as the result of discrete pulses of high-sulphidation magmatic fluids. The δ34SVCDT range in sulphides (−5.9 to −2.8 ) is compatible either with: (i) hybrid sulphur sources (i.e., magmatic and sedimentary or metasedimentary); or (ii) a sole magmatic source involving magmas that derived from partial melting of sedimentary rocks or underwent crustal assimilation. In their overall contents in critical elements (In, Ga and Ge), the key minerals in the Poopó deposit, based on their abundance in the deposit and compositions, are rhodostannite, franckeite, cassiterite, stannite and, less importantly, teallite, sphalerite and jamesonite

Nationality and migration in modern Mexico

Scholarship on nationalism and the state has examined how immigration and nationality policy create boundaries of inclusion and exclusion. While a handful of countries of immigration have been analysed extensively, explanations of nationality law have not accounted adequately for countries of emigration. This paper's historical analysis of Mexican nationality law and its congressional debate demonstrates that the ways the state has defined nationality at different periods cannot be attributed simply to demographic migration patterns or legacies of past understandings of ethnic or state-territorial nationhood, according to the expectations of received theory. The literature's focus on geopolitically stronger countries of immigration obscures the critical effects of inter-state politics on nationality law in subordinate states. Mexico's nationality laws reflect its experiences as a geopolitically weak country of immigration, despite a net out-migration of its population

Transplants: bioethics and justice Transplantes: bioética e justiça

Bioethics, as a branch of philosophy that focuses on questions relative to health and human life, is closely tied to the idea of justice and equality. As such, in understanding the concept of equality in its original sense, that is, in associating it to the idea to treat "unequals" (those who are unequal or different, in terms of conditions or circumstances) unequally (differentially), in proportion to their inequalities (differences), we see that the so-called "one-and-only waiting list" for transplants established in law no. 9.434/97, ends up not addressing the concept of equality and justice, bearing upon bioethics, even when considering the objective criteria of precedence established in regulation no. 9.4347/98, Thus, the organizing of transplants on a one-and-only waiting list, with a few exceptions that are weakly applicable, without a case by case technical and grounded analysis, according to each particular necessity, ends up institutionalizing inequalities, condemning patients to happenstance and, consequently, departs from the ratio legis, which aims at seeking the greatest application of justice in regards to organ transplants. We conclude, therefore, that from an analysis of the legislation and of the principles of bioethics and justice, there is a need for the creation of a collegiate of medical experts, that, based on medical criteria and done in a well established manner, can analyze each case to be included on the waiting list, deferentially and according to the necessity; thus, precluding that people in special circumstances be treated equal to people in normal circumstances.<br>A bioética, como ramo da filosofia que enfoca as questões relativas a saúde e a vida humana, está intimamente ligada à idéia de justiça e igualdade. Desta forma, entendendo o conceito de igualdade em sua acepção original, ou seja, associando-o à idéia de tratar desigualmente os desiguais na medida de suas desigualdades, observamos que a denominada "lista única de espera" para transplantes, prevista na Lei 9.434/97, acaba por se afastar do conceito de igualdade e justiça, norteadores da bioética, mesmo considerando os critérios objetivos de precedência previstos na Portaria n.o 3.407/98. Assim, a organização dos transplantes em lista única de espera, com tímidas exceções para alguns casos, sem a análise técnica e fundamentada, caso por caso, quanto à necessidade preeminente, acaba institucionalizando desigualdades, relegando os pacientes à própria sorte e apartando-se, assim, da ratio legis, que visa buscar maior justiça no que tange ao transplante de órgãos. Concluímos, então, a partir da análise da legislação e dos princípios da bioética e justiça, pela necessidade da criação de um colegiado de médicos experts, que baseados em critérios técnicos e de forma fundamentada, possam analisar cada caso para fins de inclusão na lista de espera, de acordo com a necessidade e preeminência, evitando-se, assim, que pessoas em situações desiguais sejam tratadas igualmente

Mineralogy and Distribution of Critical Elements in 1 the Sn-W-Pb-Ag-Zn Huanuni Deposit, Bolivia

The polymetallic Huanuni deposit, a world-class tin deposit, is part of the Bolivian tin belt. As a likely case for a "mesothermal" or transitional deposit between epithermal and porphyry Sn types (or shallow porphyry Sn), it represents a case that contributes significantly to the systematic study of the distribution of critical elements within the "family" of Bolivian tin deposits. In addition to Sn, Zn and Ag, further economic interest in the area resides in its potential in critical elements such as In, Ga and Ge. This paper provides the first systematic characterisation of the complex mineralogy and mineral chemistry of the Huanuni deposit with the twofold aim of identifying the mineral carriers of critical elements and endeavouring plausible metallogenic processes for the formation of this deposit, by means of a multi-methodological approach. With In concentrations consistently over 2000 ppm, the highest potential for relevant concentrations in this metal resides in widespread tin minerals (cassiterite and stannite) and sphalerite. Hypogene alteration assemblages are hardly developed due to the metasedimentary nature of host rocks, but the occurrence of potassium feldspar, schorl, pyrophyllite and dickite as vein material stand for potassic to phyllic or advanced argillic alteration assemblages and relatively high-temperature (and low pH) mineralising fluids. District-scale mineralogical zonation suggests a thermal zonation with decreasing temperatures from the central to the peripheral areas. A district-scale zonation has been also determined for δ34SVCDT values, which range −7.2 to 0.2 (mostly −7 to −5 ) in the central area and −4.2 to 1.0 (mainly constrained between −2 and 1 ) in peripheral areas. Such values stand for magmatic and metasedimentary sources for sulfur, and their spatial zoning may be related to differential reactivity between mineralising fluids and host rocks, outwardly decreasing from the central to the peripheral areas

Sapientia, 1997, Vol. LII, nº 202 (número completo)

Contenido: El ascenso contemplativo filosófico y místico según el Itinerarium Mentis in Deum de San Buenaventura / Ignacio Andereggen – Francisco de Vitoria : una secularización more aristotelico / Mariano Fazio Fernández – El conocimiento de la ley natural y la obligatoriedad de la ley positiva en Jean Domat : en el tricentésimo aniversario de su muerte / Camilo Tale – Los fundamentos de la Bioética de H. Tristram Engelhardt / Jorge Martínez Barrera – Sobre objetos y objetividad : aspectos del problema de la objetividad del conocimiento en el realismo clásico / Lorenzo Vicente Burgoa – La cuestión de la justicia / Carlos I. Massini Correas – La unidad de acto y contenido conceptual en el tomismo / Augusto Furlán – La persona humana, cumbre y síntesis de la creación / Luigi Bogliolo – La economía como ciencia práctica / Ricardo F. Crespo – Filosofía y cristianismo : ¿una proximidad ya pensada? / Daniel Gamarra – La evolución perfectiva de la experiencia sensible y su ordenación teleológica al conocimiento científico / Mario Enrique Sacchi – Notas y comentarios -- Bibliografí