1 The Trivers-Willard hypothesis has had only limited success T

1. The Trivers-Willard hypothesis has had only limited success. This may be because (from a methodological standpoint) it has an unusual provenance in that it is not a response to a perceived need for explanation of an observed phenomenon. At present there seems too much evidence in its favour for this hypothesis to be rejected, and too much against it, for it to be accepted.

2. My hypothesis proposes that hormone concentrations (of both parents) around the time of conception partially control the sex of the zygote. A substantial quantity of data has been

adduced in favour of this hypothesis. But it cannot explain all types of variation of sex ratios at birth.

3. It has been proposed by Catalano that other variation in sex ratios LY3009104 mw at birth is associated with maternal stress during pregnancy. He and his co-workers have adduced substantial quantities of data to support this hypothesis too. (c) 2012 Elsevier Ltd. All rights reserved.”
“The neural underpinnings of working and recognition memory have traditionally been studied in the visual

domain and these studies pinpoint the lateral prefrontal cortex (IPFC) as a primary region for visual memory processing (Miller et al., 1996; Ranganath et al., 2004; Kennerley and Wallis, 2009). Herein, we utilize single-unit recordings for the same region in monkeys (Macaca mulatta) but investigate a second modality examining auditory working and recognition memory during delayed matching-to-sample (DMS) performance. A large portion of neurons in the dorsal and selleck chemical ventral banks of the principal sulcus (area 46, 46/9) show DMS event-related activity to one or more of the following task events: auditory cues, memory delay, decision

wait time, response, and/or reward portions. Approximately 50% of the neurons show evidence of auditory-evoked activity during the task and population activity demonstrated encoding of recognition memory in the form of match enhancement. However, neither robust nor sustained delay activity was observed. The neuronal responses during the auditory DMS task are similar in many respects to those found inhibitor within the visual working memory domain, which supports the hypothesis that the IPFC, particularly area 46, functionally represents key pieces of information for recognition memory inclusive of decision-making, but regardless of modality. (c) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.”
“In this paper, we propose and analyze a prey-predator system. Here the prey population is taken as pest and the predators are those eat the pests. Moreover we assume that the prey species is infected with a viral disease forming into susceptible and infected classes and infected prey is more vulnerable to predation by the predator. The dynamical behavior of this system both analytically and numerically is investigated from the point of view of stability and bifurcation.

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