Simulating Cellular Communications in Vehicular Networks: Making SimuLTE Interoperable with Veins

The evolution of cellular technologies toward 5G progressively enables efficient and ubiquitous communications in an increasing number of fields. Among these, vehicular networks are being considered as one of the most promising and challenging applications, requiring support for communications in high-speed mobility and delay-constrained information exchange in proximity. In this context, simulation frameworks under the OMNeT++ umbrella are already available: SimuLTE and Veins for cellular and vehicular systems, respectively. In this paper, we describe the modifications that make SimuLTE interoperable with Veins and INET, which leverage the OMNeT++ paradigm, and allow us to achieve our goal without any modification to either of the latter two. We discuss the limitations of the previous solution, namely VeinsLTE, which integrates all three in a single framework, thus preventing independent evolution and upgrades of each building block.Comment: Published in: A. Foerster, A. Udugama, A. Koensgen, A. Virdis, M. Kirsche (Eds.), Proc. of the 4th OMNeT++ Community Summit, University of Bremen - Germany - September 7-8, 201

Timescale effect estimation in time-series studies of air pollution and health: A Singular Spectrum Analysis approach

A wealth of epidemiological data suggests an association between mortality/morbidity from pulmonary and cardiovascular adverse events and air pollution, but uncertainty remains as to the extent implied by those associations although the abundance of the data. In this paper we describe an SSA (Singular Spectrum Analysis) based approach in order to decompose the time-series of particulate matter concentration into a set of exposure variables, each one representing a different timescale. We implement our methodology to investigate both acute and long-term effects of $PM_{10}$ exposure on morbidity from respiratory causes within the urban area of Bari, Italy.Comment: Published in at http://dx.doi.org/10.1214/07-EJS123 the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org

Effectiveness of cognitive and physical training in slowing progression to dementia: a clinical and experimental study. Focus on relationship with cardiovascular fitness

Physical activity is beneficial to vascular health; on the other hand, vascular damage is associated with cognitive impairment. Both physical activity and a cognitively stimulating environment are known to delay the onset of dementia. The Train The Brain study evaluated the effectiveness of a comprehensive program of physical training and mental activity in delaying cognitive decline in elderly people with initial cognitive impairment, at the same time investigating the relationship between physical, vascular, neurological, and cognitive fitness. Elders age 65-89 with were recruited with the help of family physicians and territorial services. All participants underwent a neurological and cardiologic evaluation. Carotid-femoral pulse wave velocity and carotid pressure were measured with the SphygmoCor system (AtCor, Australia). Longitudinal ultrasound scans of the common carotid were performed and 10-second video clips were recorded to be analysed offline through the Cardiovascular Suite software (Quipu srl, Italy), with the computation of diameter, intima-media thickness, wall cross-sectional area, distensibility coefficient, and elastic modulus. The latter software was used also to measure endothelial function through flow mediated dilation (FMD) of the brachial artery. Subjects classified as mild cognitive impairment at the neurological examination were randomized either to standard care, or a 7-month program of physical training and environmental stimulation (lectures, games, music, social activities) three hours a week. The evaluation was then repeated. Data were obtained for 54 patients who underwent training and 36 controls. The intervention was successful in improving cognitive function as measured through the ADAS-Cog score: 11.95 (3.86) to 13.00 (4.73) for no training, 14.32 (4.27) to 12.85 (4.03) for training, time x treatment p<0.001. Pulse wave velocity showed no significant effect (p=0.5). FMD improved with intervention (no training: 3.20 (2.03) to 2.50 (1.77) %; training: from 2.82 (2.19) to 3.42 (1.82); p=0.014). All selected carotid parameters were influenced by the combination of time and treatment, in a diverging trend, at a statistically significant level, with intervention determining less dilated, less thick and less stiff vessels. None of the parameters measured analysing the vessels showed a correlation The proposed 7-months program improved cognitive function in elders with initial cognitive impairment. There was a significant difference in behaviour in time of the two groups as for endothelial function and carotid enlargement, wall thickening and arterial stiffening. The intervention seems to oppose the typical harmful effects of aging on vessels; at the same time, the positive effects on cognition and vascular health do not appear as directly correlated

Headquarters involvement, socialization, and entrepreneurial behaviors in MNC subsidiaries

Headquarters of multinational corporations can be involved in their subsidiaries and help with the development and transfer of innovative ideas. However, headquarters involvement might not always be desired or needed, and it can thus be perceived as interference with local activities, potentially reducing local willingness to go the extra mile. We address the lack of knowledge about subsidiary manager behavior by answering the following question: How does headquarters involvement influence the proactive behavior of subsidiary managers to push for new and innovative ideas? Using data from 120 top managers in subsidiaries of multinational corporations, we find that the negative relationship between headquarters involvement and their subsidiary managers' support for initiatives can be reduced when socialization mechanisms such as a common corporate culture or rotation programs are put in place

A distributed power-saving framework for LTE Het-Nets exploiting Almost Blank Subframes

Almost Blank Subframes (ABS) have been defined in LTE as a means to coordinate transmissions in heterogeneous networks (HetNets), composed of macro and micro eNodeBs: the macro issues ABS periods, and refrains from transmitting during ABSs, thus creating interference-free subframes for the micros. Micros report their capacity demands to the macro via the X2 interface, and the latter provisions the ABS period accordingly. Existing algorithms for ABS provisioning usually share resources proportionally among HetNet nodes in a long-term perspective (e.g., based on traffic forecast). We argue instead that this mechanism can be exploited to save power in the HetNet: in fact, during ABSs, the macro consumes less power, since it only transmits pilot signals. Dually, the micros may inhibit data transmission themselves in some subframes, and optimally decide when to do this based on knowledge of the ABS period. This allows us to define a power saving framework that works in the short term, modifying the ABS pattern at the fastest possible pace, serving the HetNet traffic at reduced power cost. Our framework is designed using only standard signaling. Simulations show that the algorithm consumes less power than its competitors, especially at low loads, and improves the UE QoS

Cardiovascular effects of arsenic: clinical and epidemiological findings

Several population studies relate exposure to high levels of arsenic with an increased incidence of ischemic heart disease and cardiovascular mortality. An association has been shown between exposure to high levels of arsenic and cardiovascular risk factors such as hypertension and diabetes mellitus, and vascular damage such as subclinical carotid atherosclerosis. The mechanisms underlying these phenomena are currently being studied and appear to indicate an alteration of vascular function. However, the effects of low levels of exposure to arsenic and their potential detrimental cardiovascular effect are less explored. The article provides an overview of the pathophysiologic mechanisms linking lowlevel arsenic exposure to the occurrence of cardiovascular disease and its complications, and some potential preventive strategies to implement.

The Relational Antecedents of Interpersonal Helping: ‘Quantity’, ‘Quality’ or Both?

Having a large network of colleagues means having several opportunities to help those colleagues, as well as a higher chance of receiving requests for help from them. Employees with large networks are therefore expected to help more in the workplace than those with small networks. However, large networks are also associated with cognitive costs, which may reduce the focal employee's ability to both recognize the need for help and engage in helping behaviours. For these reasons, the authors assert an inverted U-shaped relation between the size of an ego's social network and engagement in helping behaviour. However, high-quality relationships imply higher mutual understanding between the actors, and hence lower cognitive costs. In turn, the position (and threshold) of the curve between network size and interpersonal helping should be influenced by the quality of the relationship between the provider and the beneficiaries of help. Analysis of employee-level, single-firm data supports these ideas, providing preliminary evidence that quality of relationship compensates for the difficulties that may arise from having large social networks

Variation in sequence and location of the fumonisin mycotoxin niosynthetic gene cluster in Fusarium

In Fusarium, the ability to produce fumonisins is governed by a 17-gene fumonisin biosynthetic gene (FUM) cluster. Here, we examined the cluster in F. oxysporum strain O-1890 and nine other species selected to represent a wide range of the genetic diversity within the GFSC

Practical large-scale coordinated scheduling in LTE-Advanced networks

In LTE-Advanced, the same spectrum can be re-used in neighboring cells, hence coordinated scheduling is employed to improve the overall network performance (cell throughput, fairness, and energy efficiency) by reducing inter-cell interference. In this paper, we advocate that large-scale coordination can be obtained through a layered solution: a cluster of few (i.e., three) cells is coordinated at the first level, and clusters of coordinated cells are then coordinated at a larger scale (e.g., tens of cells). We model both small-scale coordination and large-scale coordination as optimization problems, show that solving them at optimality is prohibitive, and propose two efficient heuristics that achieve good results, and yet are simple enough to be run at every Transmission Time Interval (TTI). Detailed packet-level simulations show that our layered approach outperforms the existing ones, both static and dynamic