First year growth in the lithodids Lithodes santolla and Paralomis granulosa reared at different temperatures

The southern king crab, Lithodes santolla Molina, and stone crab, Paralomis granulosa Jacquinot, inhabit the cold-temperate waters of southernmost South America (southern Chile and Argentina), where stocks of both species are endangered by overfishing. Recent investigations have shown that these crabs show life-cycle adaptations to scarcity of food and low temperatures prevailing in subantarctic regions, including complete lecithotrophy of all larval stages and prolonged periods of brooding and longevity. However, growth and development to maturity are slow under conditions of low temperatures, which may explain the particular vulnerability of subpolar lithodids to fisheries. In the present study, juvenile L. santolla and P. granulosa were individually reared in the laboratory at constant temperatures ranging from 3–15 °C, and rates of survival and development through successive instars were monitored throughout a period of about nine months from hatching. When the experiments were terminated, L. santolla had maximally reached juvenile instar IV (at 6 °C), V (9 °C), or VII (15 °C). In P. granulosa the maximum crab instar reached was II (at 3 °C), V (6 °C), V (9 °C), or VII (15 °C). The intermoult period decreased with increasing temperature, while it increased in successively later instars. In consequence, growth rate showed highly significant differences among temperatures (P<0.001). Growth-at-moult was highest at 9 °C. Rates of survival decreased significantly in juvenile P. granulosa with increasing temperature. Only at 15 °C in L. santolla, was a significantly enhanced mortality found compared with lower temperatures. Our results indicate that juvenile stages of L. santolla and P. granulosa are well adapted to 5–10°C, the range of temperatures typically prevailing in subantarctic marine environments. In spite of causing higher mortality rates, higher rearing temperatures (12–15 °C) should accelerate the rates of growth and maturation, which may be favourable for projects aiming at aquaculture or repopulation of overexploited king crab stocks

Deciding Entailments in Inductive Separation Logic with Tree Automata

Separation Logic (SL) with inductive definitions is a natural formalism for specifying complex recursive data structures, used in compositional verification of programs manipulating such structures. The key ingredient of any automated verification procedure based on SL is the decidability of the entailment problem. In this work, we reduce the entailment problem for a non-trivial subset of SL describing trees (and beyond) to the language inclusion of tree automata (TA). Our reduction provides tight complexity bounds for the problem and shows that entailment in our fragment is EXPTIME-complete. For practical purposes, we leverage from recent advances in automata theory, such as inclusion checking for non-deterministic TA avoiding explicit determinization. We implemented our method and present promising preliminary experimental results

Extended hatching periods in the subantarctic lithodid crabs Lithodes santolla and Paralomis granulosa (Crustacea: Decapoda: Lithodidae)

Temporal pattern of hatching was studied in the subantarctic lithodid crabs Lithodes santolla (Molina) and Paralomis granulosa (Jaquinot) from the Argentine Beagle Channel. In both species, larval hatching occurred in low daily numbers over an extended period of up to several weeks, depending on hatch size. Low daily hatching activity and low oxygen-consumption rates in freshly hatched P. granulosa larvae are discussed as life history adaptations to, and/or physiological constraints by, the environmental conditions of high latitudes. <br/

Pflegeintervention zur Verminderung der Belastung von pflegenden Angehörigen demenzkranker Menschen: eine systematische Literaturreview

Die demographische Entwicklung zeigt für die nächsten Jahrzehnte eine steigende Lebenserwartung an. Demenz als altersabhängige hirnorganische Störung ist seit längerem als ein zentrales Problem des Gesundheitswesens anerkannt (Höpflinger und Hugentobler, 2003). Von den rund 96'000 Menschen mit Demenz in der Schweiz werden 60% von Angehörigen oder Freunden zu Hause betreut. Angehörige erleben durch die Betreuung eines demenzkranken Menschen tiefgreifende Veränderungen in nahezu allen Lebensbereichen. Häufig geraten die Angehörigen durch die intensive Betreuung an die Grenzen ihrer Belastbarkeit. Dies hat Auswirkungen auf die psychische und physische Gesundheit der Angehörigen. Der Entlastung der steigenden Anzahl betroffener Angehöriger von Demenzkranken kommt deshalb eine zentrale Bedeutung zu. Für Pflegefachleute ist wichtig, dass sie auf evidenzbasiertes Wissen zurückgreifen können, um die Angehörigen in ihrer Aufgabe effektiv unterstützen zu können. Die vorliegende systematische Literaturreview gibt einen Überblick über verschiedene pflegerische Interventionen und deren positiven Einfluss auf die Angehörigen. Die Interventionen werden anhand der Kategorien Information- Instruktion, Ausbildungsprogramme, kognitive Verhaltenstherapie, Entlastungspflege und allgemeine Unterstützung diskutiert. Grundsätzlich haben alle Interventionen einen zwar kleinen aber positiven Effekt auf einen Teilbereich der Belastung der pflegenden Angehörigen. Den grössten Erfolg versprechen aber Interventionen, die sich auf die individuellen Bedürfnisse der Angehörige stützen und über einen längeren Zeitraum angeboten werden

Differential growth of the barnacle Notobalanus flosculus (Archaeobalanidae) onto artificial and live substrates in the Beagle Channel, Argentina

In the Beagle Channel, southern South America (ca. 55°S 67°W), about 20% of false king crabs (Paralomis granulosa) >80 mm carapace length are fouled with the barnacle Notobalanus flosculus. To evaluate differences in growth rates of barnacles attached to artificial and live substrates, clay tiles were anchored as collectors to the bottom at two different sites in the Beagle Channel in September 1996: in Ushuaia harbour (low currents and high levels of suspended matter) and around the Bridges Islands (strong currents and low level of suspended matter). Another set of collectors was deployed at the same sites in October 1998 to collect barnacles for histological studies. Tiles were removed from each place, approximately, on a monthly basis. Carapaces of P. granulosa with the epizoic N. flosculus were sampled between November 1996 and 1997, and between March 1998 and September 1999, to study sexual maturation of barnacles. Growth of barnacles was compared between the collectors and P. granulosa carapaces following a qualitative approach. A sexual maturity scale was defined, based on the stage of development of the female reproductive apparatus of N. flosculus. Growth rate of barnacles was highest in the harbour, intermediate on P. granulosa, and lowest around the Bridges Islands. Presence of oocytes was registered only in epizoic barnacles, suggesting that at least a proportion of these individuals is able to spawn on the carapaces. The potential advantages of settling on a living substrate, namely increased availability of food particles and decreased predation risks are discussed. © Springer-Verlag and AWI 2005.Fil:Venerus, L.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Calcagno, J.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Lovrich, G.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Nahabedian, D.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Effects of physical disturbance on a sub-Antarctic middle intertidal bivalve assemblage

Physical stress is known as the prevailing environmental force structuring many intertidal communities globally. Here, we present for the first time the vulnerability to disturbance of a bivalve assemblage situated in the middle intertidal in the Atlantic coast of the Southern tip of South America (ca 53º 36´S, 67º 58’W). This intertidal zone is characterized by a high level of sand movement preventing any establishment of sessile organisms on vertical sides of rock outcrops. The benthic assemblage inhabiting rock surfaces of this physically dynamic intertidal zone has been poorly studied although this coast is prone to potential spills from nearby hydrocarbon marine platforms. In February 2001, we exposed the assemblage to two different experimental conditions: a complete removal and a physical disturbance, and tracked its recovery during the following 4 years. The disturbance lowered the diversity of associated fauna and made disappear the sediment layer trapped among bivalves, which was not restored any longer. Mytilus chilensis recruited massively into crevices or between byssi in the following settlement season, i.e. summer 2002. The recuperation of mussel coverage to predisturbance levels took 3 years after the total removal. In April 2004 the size frequency distributions, density and biomass/number ratio of M. chilensis were similar to those at the start of the experiment. Perumytilus purpuratus recovered slower than M. chilensis probably due to its lower growth rate compared to M. chilensis and dependence of an adequate byssus matrix for settlement. Moreover, the main apparent stressor was the irruption of sand that can cover the bivalve assemblage for variable periods of time. This assemblage is characterized by low predatory pressure and therefore we hypothesize that this bivalve assemblage is predominantly controlled by competition for space

Relevance of the serial position effect in the differential diagnosis of mild cognitive impairment, Alzheimer-type dementia, and normal ageing

Serial position effects are observed when a person memorises a series of words exceeding his or her attention span. Cognitively normal individuals recall words at the beginning and end of the list more frequently than those in the middle, which reflects the way that short- and long-term episodic memory works. Objective: To study the serial position effect in patients with mild cognitive impairment (MCI) compared to subjects with Alzheimer-type dementia (AD) or normal ageing (NA). Methods: 30 AD, 25 MCI and 20 NA subjects underwent neurological and neuropsychological assessment. The Rey Auditory Verbal Learning Test (RAVLT) was used to study primacy, middle, and recency effects and delayed recall for each group. Results: The general memory pattern of MCI subjects was very similar to that of AD subjects, and was characterised by reduced learning capacity, rapid forgetfulness and clear recency effect in learning. With regard to delayed recall, however, there were differences in performance; MCI subjects’ ability to recall words at the beginning and middle of the list was similar to that of normal subjects, while their memory of words at the end of the list was poor, as in AD subjects. Conclusions: RAVLT is a tool permitting us to distinguish between MCI and NA subjects. The recency index for the delayed recall task is a valid indicator for distinguishing between MCI patients and patients with normal ageing. Resumen: Los efectos de posición serial son estudiados cuando se memoriza una serie de palabras que excede el span atencional. En sujetos normales son recordadas más frecuentemente las palabras del inicio y final de una lista reflejando el funcionamiento de la memoria episódica a corto y largo plazo. Objetivos: Estudiar el efecto de principio y el de fin de lista en pacientes con deterioro cognitivo leve (DCL) y compararlo con demencia tipo Alzheimer (DTA) y sujetos con envejecimiento normal (SN). Métodos: Fueron evaluados neurológica y neuropsicológicamente 30 pacientes con DTA, 25 con DCL y 20 SN. Se utilizó el Test de aprendizaje auditivo de una lista de palabras de Rey en donde se evaluó el efecto de principio, medio y fin de lista en cada ensayo y su efecto en el recuerdo diferido. Resultados: Los sujetos con DCL mostraron un patrón general de memoria similar a los sujetos con DTA, caracterizado por una reducción en el aprendizaje, olvido acelerado y un claro efecto de fin de lista en el aprendizaje. A nivel del recuerdo diferido mostraron un patrón diferencial recordando palabras de principio y medio más cercano a los normales pero no recordando las finales de la lista como las DTA. Conclusiones: La prueba de aprendizaje de una lista de palabras es una herramienta que nos permite discriminar entre pacientes con DCL y SN. El índice de recencia en el recuerdo diferido es un indicador útil para diferenciar el envejecimiento normal de los pacientes con DCL. Keywords: Mild cognitive impairment, Alzheimer-type dementia, Serial position effect, Neuropsychological assessment, Memory, Neuropsychology, Palabras clave: Deterioro cognitivo leve, Demencia de tipo Alzheimer, Efecto de posición serial, Evaluación neuropsicológica, Memoria, Neuropsicologí