A change in subtask order in the psychological refractory period (PRP) paradigm increases the effect of stimulus onset asynchrony (SOA) on the second response. We used a paradigm with cued, randomly determined subtask order to test the hypothesis that this SOA by order switch overadditivity reflects order control, via "copying" stimulus order. In Experiments 1a and 1b, overadditivity was eviden...

The negative effects of large larval concentration on larval development have been reported for many marine planktotrophic invertebrates. Comparable data for the lecithotrophic species are, however, not available. The present study was therefore undertaken to determine the influence of varying larval concentrations on the developmental performance of Babylonia formosae (Sowerby). The larvae of ...

aim: this study investigates the intraspecific competition, for food and density amongst larvae of anopheles stephensi (main malaria vector in south iran). material & methods: the effects of 4 selected food quantities (1x,2x,4x,6x) and 5 larval densities (0.1 to 3 larva/cm2) were tested individually or in combination on 7 biological indexes of the vector and the results were statistically ...

Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alte...

Circadian pacemaker neurons in the Drosophila brain control daily rhythms in locomotor activity. These pacemaker neurons can be subdivided into early or late groups depending on whether rhythms in period (per) and timeless (tim) expression are initiated at the first instar (L1) larval stage or during metamorphosis, respectively. Because CLOCK-CYCLE (CLK-CYC) heterodimers initiate circadian osci...

Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion, which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggreg...

Connectivity among marine populations is critical for persistence of metapopulations, coping with climate change, and determining the geographic distribution of species. The influence of pelagic larval duration (PLD) on connectivity has been studied extensively, but relatively little is known about the influence of other biological parameters, such as the survival and behavior of larvae, and th...

IN the previous communication (Yao, 1949ft), alkaline phosphatase has been shown to be in some way connected with histo-differentiation during Drosophila embryogenesis. The post-embryonic development of Drosophila includes, besides a period of larval growth, the phenomenon of metamorphosis which involves the destruction of most larval organs and the simultaneous development of imaginal organs f...

Insect metamorphosis is a compelling example for dendritic and synaptic remodeling as larval and adult behaviors place distinct demands on the CNS. During the metamorphosis of the moth, Manduca sexta, many larval motoneurons are remodeled to serve a new function in the adult. During late larval life, steroid hormones trigger axonal and dendritic regression as well as larval synapse elimination....

As the German contribution to the Southern Ocean Global Ocean Ecosystems Dynamics Study (SO GLOBEC), RV Polarstern visited the Eastern Bellingshausen Sea between 18 April and 1 May 2001. This paper examines in situ feeding cycles, ingestion rates and growth of larval krill Euphausia superba. Larval krill were exceptionally numerous, especially over the shelf break and continental slope: mean 88...