Was human evolution driven by Pleistocene climate change?

Modern humans are probably a product of social and anatomical preadaptations on the part of our Miocene australopithecine ancestors combined with the increasingly high amplitude, high frequency climate variation of the Pleistocene. The genus Homo first appeared in the early Pleistocene as ice age climates began to grip the earth. We hypothesize that this co-occurrence is causal. The human ability to adapt by cultural means is, in theory, an adaptation to highly variable environments because cultural evolution can better track rapidly changing environments than can genes. High resolution ice and sediment cores published in the early 1990s showed the last ice age was characterized by high amplitude millennial and submillenial scale variation, exactly the sort of variation mathematical models suggest should favor a costly capacity for culture. More recent cores suggest that over the last several 100 thousand year glacial cycles the amount of millennial scale variation has increased rather dramatically in parallel with increases in hominin brain size and sophistication of the artifacts they made

Divorce, Academic Performance, and Attachment Styles in College Students

For years, social scientists have pondered the impacts of a parental divorce on the students’ academic performance, as well as their attachment style (Fomby, 2010). In the current study, it is hypothesized that students who experience a parental divorce will perform lower on academic performance and higher on the insecure attachment styles than students whose parents are still intact or remarried. Participants were 73 college students, ages ranging in age from 18-29. More than half of the study consisted of student’s ages 18-19 years. 65% of students who participated were female, and an overwhelming majority of participants were white, with nearly 80%. Non-LatinX students also comprised a large part of the study, this number also being over 80%. Students answered items from the Perceived Academic Performance Scale (Verner-Filion & Vallerand 2016). As well as the Attachment Styles Questionnaire (Verbeke, Bagozzi, & van den Berg 2014). The results were analyzed using several one-way ANOVAs. Results indicated no significant findings, with students in all three groups (divorced, remarried, intact) performing similarly on academic performance as well as similarly on attachment styles. Future directions for similar studies could perhaps be more inclusive of divorce timing, pre-divorce conditions, socioeconomic status of the parent, quality of the union being dissolved and post-divorce environment, as the research has indicated these elements are most critical

Executive Ability Difficulties in Everyday Contexts among Children with Sickle Cell Disease

Executive Ability Difficulties in Everyday Contexts among Children with Sickle Cell Disease Objective: The present study investigated the utility of the Behavior Rating Inventory of Executive Function (BRIEF) in identifying executive ability difficulties in everyday contexts among children with sickle cell disease (SCD). Method: Participants were 243 children with SCD and 409 typically-developing control children ranging from 5.0 to 18.3 years of age (M=10.5, SD=3.4). The primary outcome, reported executive ability difficulties, was assessed using the Behavior Rating Inventory of Executive Function (BRIEF) Parent Form. IQ was estimated using the Weschler Abbreviated Scale of Intelligence (WASI). Sociodemographic information was obtained from parents, and SCD characteristics were ascertained from medical records. Results: Independent samples t-tests indicated that children with SCD had poorer scores than typically-developing controls on the BRIEF Global Executive Composite Index. Additional analysis showed that their scores were also poorer than those of controls across both BRIEF indices (Behavioral Regulation, Metacognition) and the 8 individual scales of the BRIEF. Models investigating the contributions of infarct status, age, and parent education on the BRIEF Global Executive Composite, Behavioral Regulation, and Metacognition Indices indicated significant, independent associations of infarct status and parent education with each BRIEF measure, as well as a significant age by group interaction for the Behavioral Regulation Index. Conclusion: The BRIEF is of utility in identifying executive difficulties among children with SCD

Service outsourcing and billing in inter-domain IMS scenarios

ArticleResource sharing in commercial mobile networks may present operators with options to cut costs and prevent network churn. In resource sharing, when the network experiences resource constraints, the operator can negotiate with other reachable networks to outsource the provision of network access services. The revenue earned from user payments will be shared by the home operator and the serving operator. Operators participating in service outsourcing are faced with financial challenges with regard to network revenue sharing. Moreover, an operator’s users are placed under service control of the visited operator, a situation that may impact customer experience. On the other hand, the visited operator allocates network resources to visiting users, thus there is a risk of service blockage for home users. In this paper we explore resource sharing in inter-domain frameworks, and investigate factors that influence revenue distribution amongst involved operators. We develop strategies for use by operators to maximize revenue from resource sharing. This work is done in the domain of IP Multimedia Subsystem communications

Converged multimedia services in emerging Web 2.0 session mobility scenarios

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Inter-subnet localized mobility support for host identity protocol

Host identity protocol (HIP) has security support to enable secured mobility and multihoming, both of which are essential for future Internet applications. Compared to end host mobility and multihoming with HIP, existing HIP-based micro-mobility solutions have optimized handover performance by reducing location update delay. However, all these mobility solutions are client-based mobility solutions. We observe that another fundamental issue with end host mobility and multihoming extension for HIP and HIP-based micro-mobility solutions is that handover delay can be excessive unless the support for network-based micro-mobility is strengthened. In this study, we co-locate a new functional entity, subnet-rendezvous server, at the access routers to provide mobility to HIP host. We present the architectural elements of the framework and show through discussion and simulation results that our proposed scheme has achieved negligible handover latency and little packet loss

Distributed mobility management with mobile Host Identity Protocol proxy

The architectural evolution from hierarchical to flatter networks creates new challenges such as single points of failure and bottlenecks, non-optimal routing paths, scalability problems, and long handover delays. The cellular networks have been hierarchical so that they are largely built on centralized functions based on which their handover mechanisms have been built. They need to be redesigned and/or carefully optimized. The mobility extension to Host Identity Protocol (HIP) proxy, mobile HIP Proxy (MHP), provides a seamless and secure handover for the Mobile Host in the hierarchical network. However, the MHP cannot ensure the same handover performance in flatter network because the MHP has also utilized the features offered by the hierarchical architecture. This paper extends the MHP to distributed mobile HIP proxy (DMHP). The performance evaluation of the DMHP in comparison to MHP and other similar mobility solutions demonstrates that DMHP does indeed perform well in the flatter networks. Moreover, the DMHP supports both efficient multi-homing and handover management for many mobile hosts at the same time to the same new point of attachment