A traditional floodplain fishery of the lower Amazon River, Brazil

This paper describes fishing activities of households in four communities located in a floodplain lake system of the lower Amazon river. An average of 42 households were interviewed about their fishing activity on a monthly basis. The fishery is a typical multi-gear, multi-specific artisanal fishery. Approximately ten types of fishing gear are utilized, of which the three main types of gillnets account for 51% of the total catch. The catch per trip averaged 15 kg, for an annual total of 2,295 kg per household. Some 40 species or groups of species are caught, although four species account for 50% of the total. There is a strong seasonal pattern to the fishery, with catch per trip and catch per unit effort (CPUE) highest in the low water season (September-November). While there are marked differences between subsistence and commercially oriented fishing strategies, these differences are more in degree than in type, since fishers use the same types of gear and most fishers regularly sell part of their catch

A model of context-dependent component connectors

Recent approaches to component-based software engineering employ coordinat- ing connectors to compose components into software systems. For maximum flexibility and reuse, such connectors can themselves be composed, resulting in an expressive calculus of connectors whose semantics encompasses complex combinations of synchronisation, mutual exclusion, non-deterministic choice and state-dependent behaviour. A more expressive notion of connector includes also context-dependent behaviour, namely, whenever the choices a connector can take change non-monotonically as the context, given by the pending activity on its ports, changes. Context dependency can express notions of priority and inhi- bition. Capturing context-dependent behaviour in formal models is non-trivial, as it is unclear how to propagate context information through composition. In this paper we present an intuitive automata-based formal model of context- dependent connectors, and argue that it is superior to previous attempts at such a model for the coordination language Reo

Do static sources respond to massive scalar particles from the Hawking radiation as uniformly accelerated ones do in the inertial vacuum?

We revisit the recently found equivalence for the response of a static scalar source interacting with a {\em massless} Klein-Gordon field when the source is (i) static in Schwarzschild spacetime, in the Unruh vacuum associated with the Hawking radiation and (ii) uniformly accelerated in Minkowski spacetime, in the inertial vacuum, provided that the source's proper acceleration is the same in both cases. It is shown that this equivalence is broken when the massless Klein-Gordon field is replaced by a {\em massive} one.Comment: 4 pages, 2 figure

Bosonic String and String Field Theory: a solution using Ultradistributions of Exponential Type

In this paper we show that Ultradistributions of Exponential Type (UET) are appropriate for the description in a consistent way string and string field theories. A new Lagrangian for the closed string is obtained and shown to be equivalent to Nambu-Goto's Lagrangian. We also show that the string field is a linear superposition of UET of compact support CUET). We evaluate the propagator for the string field, and calculate the convolution of two of them.Comment: 30 page

Video-game epilepsy: a European study.

Epilepsia. 1999;40 Suppl 4:70-4. Video-game epilepsy: a European study. Kasteleijn-Nolst Trenité DG, da Silva AM, Ricci S, Binnie CD, Rubboli G, Tassinari CA, Segers JP. Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands. [email protected] Abstract With the introduction of Nintendo video-games on a large scale, reports of children having seizures while playing suggested a possible specific, provocative factor. Although 50% of the photosensitive patients are also sensitive to a 50-Hz television, nonphotosensitive patients with a history of video-game seizures were described as well. The question arises whether this is a mere coincidence, provoked by fatigue and stress, is related to the reaction to the television screen itself, or depends on the movement and color of the pictures of this specific game. A European study was performed in four countries and five sites. All patients were selected because of a history of television, video- or computer-game seizures, with a history of sun-light-, discotheque-, or black and white pattern-evoked seizures, or were already known to be sensitive to intermittent photic stimulation. A total of 387 patients were investigated; 220 (75%) were female and 214 (55%) of those were < 18 years of age. After a routine examination, intermittent photic, pattern, and television stimulation were performed in a standardized way. The patients were investigated with Super Mario World and a standard relatively nonprovocative TV program, both on a 50- and 100-Hz television. Regardless of the distance, Super Mario World proved to be more provocative than the standard program (Wilcoxon, p < 0.05). Eighty-five percent showed epileptiform discharges evoked by intermittent photic stimulation. Forty-five percent of patients were 50-Hz television sensitive and 26% were 100-Hz television sensitive. Pattern sensitivity was found in 28% of patients. The patients, referred because of a television, video- or computer-game seizure, were significantly more sensitive to pattern and to the 50-Hz television (chi square, p < 0.001). More patients are sensitive when playing Super Mario, compared with the standard program (Wilcoxon, p = 0.001) and more sensitive with playing versus viewing (p = 0.016). Of the patients who were referred because of seizures in front of the television, or evoked by a video- or computer game, 14% proved not to be photosensitive. Although no difference in age or use of medication was found, twice as many men were found in this nonphotosensitive group. PMID: 10487177 [PubMed - indexed for MEDLINE

Suscetibilidade da Bacia do Rio Bengalas a deslizamentos de terra

Landslides have frequently occurred in last years, due to the disorderly grownth of the cities and the occupation of risk areas by the poor population, causing social, environmental and economic impacts. Urban areas in expansion move to geologically unstable areas and topographically inclined, such as the Basin of River Bengalas, located in the city of Nova Friburgo, mountainous region of the State of Rio de Janeiro, Brazil. This article aims to present the model survey to assess the susceptibility of the Basin of River Bengalas to landslides, which in january 2011, with the occurrence of heavy rains, caused landslides that impacted in the death of 429 people in city of Nova Friburgo. For the case study, several investigations have been made related to the areas of the basin, such as slope, soil conditions, lithology, land use and cover, vertical and horizontal curvatures. With this study it was possible to understand how the natural and anthropics elements of the basin are related to the local dynamics of the disasters regarding to their interferences in the induction of landslides, thus enabling improved public management of the Municipality regarding the use and division of land, from the identification of areas Basin of River Bengalas susceptible to landslides

The DNA damage response is developmentally regulated in the African trypanosome

Genomes are affected by a wide range of damage, which has resulted in the evolution of a number of widely conserved DNA repair pathways. Most of these repair reactions have been described in the African trypanosome Trypanosoma brucei, which is a genetically tractable eukaryotic microbe and important human and animal parasite, but little work has considered how the DNA damage response operates throughout the T. brucei life cycle. Using quantitative PCR we have assessed damage induction and repair in both the nuclear and mitochondrial genomes of the parasite. We show differing kinetics of repair for three forms of DNA damage, and dramatic differences in repair between replicative life cycle forms found in the testse fly midgut and the mammal. We find that mammal-infective T. brucei cells repair oxidative and crosslink-induced DNA damage more efficiently than tsetse-infective cells and, moreover, very distinct patterns of induction and repair of DNA alkylating damage in the two life cycle forms. We also reveal robust repair of DNA lesions in the highly unusual T. brucei mitochondrial genome (the kinetoplast). By examining mutants we show that nuclear alkylation damage is repaired by the concerted action of two repair pathways, and that Rad51 acts in kinetoplast repair. Finally, we correlate repair with cell cycle arrest and cell growth, revealing that induced DNA damage has strikingly differing effects on the two life cycle stages, with distinct timing of alkylation-induced cell cycle arrest and higher levels of damage induced death in mammal-infective cells. Our data reveal that T. brucei regulates the DNA damage response during its life cycle, a capacity that may be shared by many microbial pathogens that exist in variant environments during growth and transmission