11,983 research outputs found
Fishes of the Lagunas Encadenadas (Province of Buenos Aires, Argentina), a wetland of international importance
The Lagunas Encadenadas form a large endorheic wetland. The system comprises a chain of five main lagoons (Alsina, Chochico, Del Monte, Del Venado, and Epecuen). During two recent collection trips, 13 species of fish were caught. From the collected material and available data in the literature the following points can be made: The fish fauna of this wetland comprises 18 species from 11 families and six orders. Four species (Cyprinus carpio, Hoplias malabaricus, Loricariichthys anus and Parapimelodus valenciennis) are new records for these water bodies. Fish species diversity decreases from east to west, ie from the most freshwater lagoon (Alsina, with 15 species) to the most saline (Epecuen, 1 species). A similar diversity pattern has been found in zooplankton species
The Execution of the Innocent
Radelet and Bedau discuss the continuing and regular incidence of American trial courts sentencing innocent defendants to death, which was one of the problems that gave rise to the ABA\u27s moratorium on capital punishment
Limnology in Argentina: An historical account
This short review includes major books, articles and episodes concerned with studies on inland waters that have affected the development of limnology in Argentina. It is divided into three periods; (1) an early period of protolimnologists; (2) a period previous to the present times, subdivided into a first stage from 1900 to 1938 and a second stage from 1938 to 1962; and (3) a period of integrated research
Dissipation-assisted quantum computation in atom-cavity systems
The principal obstacle to quantum information processing with many qubits is
decoherence. One source of decoherence is spontaneous emission which causes
loss of energy and information. Inability to control system parameters with
high precision is another possible source of error. Strategies aimed at
overcoming one kind of error typically increase sensitivity to others. As a
solution we propose quantum computing with dissipation-assisted quantum gates.
These can be run relatively fast while achieving fidelities close to one. The
success rate of each gate operation can, at least in principle, be arbitrary
close to one.Comment: proceedings for the SPIE conference on Fluctuations and Noise, June
2003 in Santa Fe, 12 pages, minor change
von Neumann-Morgenstern and Savage Theorems for Causal Decision Making
Causal thinking and decision making under uncertainty are fundamental aspects
of intelligent reasoning. Decision making under uncertainty has been well
studied when information is considered at the associative (probabilistic)
level. The classical Theorems of von Neumann-Morgenstern and Savage provide a
formal criterion for rational choice using purely associative information.
Causal inference often yields uncertainty about the exact causal structure, so
we consider what kinds of decisions are possible in those conditions. In this
work, we consider decision problems in which available actions and consequences
are causally connected. After recalling a previous causal decision making
result, which relies on a known causal model, we consider the case in which the
causal mechanism that controls some environment is unknown to a rational
decision maker. In this setting we state and prove a causal version of Savage's
Theorem, which we then use to develop a notion of causal games with its
respective causal Nash equilibrium. These results highlight the importance of
causal models in decision making and the variety of potential applications.Comment: Submitted to Journal of Causal Inferenc
Single hole and vortex excitations in the doped Rokhsar-Kivelson quantum dimer model on the triangular lattice
We consider the doped Rokhsar-Kivelson quantum dimer model on the triangular
lattice with one mobile hole (monomer) at the Rokhsar-Kivelson point. The
motion of the hole is described by two branches of excitations: the hole may
either move with or without a trapped Z2 vortex (vison). We perform a study of
the hole dispersion in the limit where the hole hopping amplitude is much
smaller than the interdimer interaction. In this limit, the hole without vison
moves freely and has a tight-binding spectrum. On the other hand, the hole with
a trapped vison is strongly constrained due to interference effects and can
only move via higher-order virtual processes.Comment: 4 pages, 4 figures; minor changes, replaced by published versio
Economic perspectives for Central America after CAFTA; a GTAP-based analysis
Using a GTAP CGE application, we assess the main economic results of CAFTA for Central America (CA). Currently, Central America enjoys preferential access to the US market through the Caribbean Basin Initiative (CBI). CAFTA will consolidate and augment these concessions. Meanwhile, the agreement requires widespread opening of CA markets to US imports over time. The implementation of the ATC protocol in 2005 implies increased Chinese competition for the region in the textile and apparel sectors. CAFTA will balance for this new source of competition by allowing better access for CA textiles and apparel products, while creating large opportunities for labour market improvements and FDI inflows to Central America. If these opportunities are exploited, the region has much to gain from CAFTA. However, we also find a strong sectoral readjustment from agricultural sectors to maquila-based industries, which could create important adjustment strains.
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