Noisy neighbours at the frog pond: effects of invasive cane toads on the calling behaviour of native Australian frogs

Invasive species can disrupt the communication systems that native biota use for reproductive interactions. In tropical Australia, invasive cane toads (Rhinella marina) breed in many of the same waterbodies that are used by native frogs, and males of both the invader and the native taxa rely on vocal signals to attract mates. We conducted playback experiments to test the hypothesis that calls of toads may influence the calling behaviour of frogs (Limnodynastes convexiusculus and Litoria rothii). Male L. convexiusculus adjusted their calling rate and the variance in inter-call interval in response to a variety of sounds, including the calls of cane toads as well as those of other native frog species, and other anthropogenic noise, whereas L. rothii did not. Within the stimulus periods of playbacks, male L. convexiusculus called more intensely during long silent gaps than during calling blocks. Thus, males of one frog species reduced their calling rate, possibly to minimise energy expenditure during periods of acoustic interference generated by cane toads. In spite of such modifications, the number of overlapping calls (within stimulus periods) did not differ significantly from that expected by chance. In natural conditions, the calls of cane toads are continuous rather than episodic, leaving fewer gaps of silence that male frogs could exploit. Future work could usefully quantify the magnitude of temporal (e.g. diel and seasonal) and spatial overlap between calling by toads and by frogs and the impact of call-structure shifts on the ability of male frogs to attract receptive females.

Prosthetic motor imaginary task classification using single channel of electroencephalography

Brain Computer Interface (BCI) is playing a very important role in human machine communications. Recent communication systems depend on the brain signals for communication. In these systems, users clearly manipulate their brain activity rather than using motor movements in order to generate signals that could be used to give commands and control any communication devices, robots or computers. In this paper, the aim was to estimate the performance of a brain computer interface (BCI) system by detecting the prosthetic motor imaginary tasks by using only a single channel of electroencephalography (EEG). The participant is asked to imagine moving his arm up or down and our system detects the movement based on the participant brain signal. Some features are extracted from the brain signal using Mel-Frequency Cepstrum Coefficient and based on these feature a Hidden Markov model is used to help in knowing if the participant imagined moving up or down. The major advantage in our method is that only one channel is needed to take the decision. Moreover, the method is online which means that it can give the decision as soon as the signal is given to the system. Hundred signals were used for testing, on average 89 % of the up down prosthetic motor imaginary tasks were detected correctly. This method can be used in many different applications such as: moving artificial prosthetic limbs and wheelchairs due to it's high speed and accuracy.

Cytokine networks and cancer stem cells

Cell-to-cell communication is an integral function of multicellular organisms. Many of these signals are received by a myriad of cell-surface receptors that utilize a range of intracellular signaling pathways to communicate this to the nucleus, rapidly impacting on the transcription of target genes in order to elicit the desired response, such as proliferation, differentiation, activation, and survival. Dysregulation of these important signaling pathways, and networks, often lead to pathological conditions due to inappropriate cell responses with negative consequences. The aberrant signaling pathways have been associated with many diseases, including cancer. Cytokines and chemokines convey a multitude of messages to the target cell, many of which are beneficial for cancers and cancer stem cells, such as proliferation, survival and migration. By hijacking this communication network, cancers and cancer stem cells can become invasive and more pathogenic. Furthermore, by using these communication systems, cancer stem cells are able to evade current therapies. Therefore, novel therapies may be developed to break the communication systems of the cancer stem cells. This chapter explores the role of the cytokines TGF-β, TNF-α, IL-1 and IL-6 and chemokine CXCL8 as well as NF-κB and their role in cancer stem cell survival and maintenance. Emerging therapies are beginning to target the cancer stem cell population, either specifically or synergistically with existing therapeutic options. These novel therapies may hold the key to breaking the communication network of cancer stem cells.

A novel energy-efficient cross-application-layer platform with QoS-security support

Security provisioning is an essential part in the design of any communication systems, which becomes more critical for wireless systems. Devising a quality of service (QoS) mechanism to coexist security algorithms is a daunting, yet inevitable task. The aim of this novel research article is to present a novel energy efficient, cross-layer-based application-layer wireless system with simultaneous security and QoS supports, which revolves around the practical and low-cost implementation of Suite-B cryptographic algorithms (promulgated by the National Security Agency) and detailed analyses of the associated complexities. The focus of this article is on the novel cross-layer mechanism and its effectiveness to handle QoS-enabled treatment while offering security enhancements.

Communication network analysis of the enterprise grid systems

This paper addresses the problem of performance analysis based on communication modelling of largescale heterogeneous distributed systems with emphases on enterprise grid computing systems. The study of communication layers is important because the overall performance of a distributed system is often critically hinged on the effectiveness of this part. This model considers processor as well as network heterogeneity of target system. The model is validated through comprehensive simulation, which demonstrates that the proposed model exhibits a good degree of accuracy for various system sizes and under different working conditions. The proposed model is then used to investigate the performance analysis of typical systems.

The potential for improving intra-organizational communication in the process of mergers and acquisitions via accounting systems

As the number of mergers and acquisitions (M&A) continues to increase on a global basis, more managers are called upon to develop their M&A transition skills. While, undoubtedly, organizations realise the importance of good communications for successful implementation of change programs throughout the entire M&A process, they often find it hard to make this communication both constant and lucid. The article argues that accounting systems display the potential for improving intra-organizational communication by infusing managers and 'non-accountants' with a common financial vocabulary for communication and 'reading' the state of the business.

Analytical modeling of communication latency in multi-cluster systems

This paper addresses the problem of performance modeling of large-scale distributed systems with emphasis on communication networks in heterogeneous multi-cluster systems. The study of interconnection networks is important because the overall performance of a distributed system is often critically hinged on the effectiveness of this part. We present an analytical model to predict message latency in multi-cluster systems in the presence of processor heterogeneity. The model is validated through comprehensive simulation, which demonstrates that the proposed model exhibits a good degree of accuracy for various system sizes and under different operating conditions.

Supporting emotion communication in information systems

Society is becoming increasingly reliant on Information Systems to meet its everyday communication requirements, yet many current implementations lack support for important conversational cues. One such cue is emotion communication. Emotion communication carries with it many signals that affect our behaviour, the interpretation of the message and provide a catalyst to other forms of communication such as empathy and the formation of social ties. Emotion itself can affect the very decision to communicate, or the way in which one may respond to a given communication. To explore the ways in which systems may better support emotion communication between members of a social group, a cloud-based information system was developed and trialled which both large and small groups. This paper presents results on how Information Systems can best support emotion communication in social groups.