176 research outputs found
Understanding the role of sexual transmission in the spread of ZIKA virus using an individual-based interconnected population model
Citation: Tanver, F., Lee, C., Mcvey, D., & Scoglio, S. (2018). Understanding the role of sexual transmission in the spread of ZIKA virus using an individual-based interconnected population model. Pre-Print, Unpublished Manuscript.Zika virus has affected the world as a long-term threat. Modeling its transmission is important in order to facilitate forecasts and control measures. We propose a novel node-based interconnected population model to simulate both vectored and sexual transmission of Zika virus. Using a sexual contact network, we incorporate heterogeneous mixing in the host population with stochastic transmission for realistic predictions. We also incorporate climatic variations in our model, which affect the mosquito vector population and consequently the arbovirus transmission. We perform extensive simulations to understand the effects of sexual transmission rate and network topology on the spreading of infections. Sexual transmission contributes to the epidemic spread and under certain conditions, can sustain it up to several months without vectors. This can potentially lead to recurrences once the mosquitoes overwinter. We also find that sexual transmission can have a stronger effect when vectored transmission is relatively weaker due to climatic conditions. Our results show that vectored and sexual transmission affect the disease dynamics differently
Spasmolytic Effects of Aphanizomenon Flos Aquae (AFA) Extract on the Human Colon Contractility.
The blue-green algae Aphanizomenon flos aquae (AFA), rich in beneficial nutrients, exerts
various beneficial effects, acting in different organs including the gut. Klamin® is an AFA extract
particularly rich in -PEA, a trace-amine considered a neuromodulator in the central nervous
system. To date, it is not clear if -PEA exerts a role in the enteric nervous system. The aims of
the present study were to investigate the effects induced by Klamin® on the human distal colon
mechanical activity, to analyze the mechanism of action, and to verify a -PEA involvement. The
organ bath technique, RT-PCR, and immunohistochemistry (IHC) were used. Klamin® reduced, in a
concentration-dependent manner, the amplitude of the spontaneous contractions. EPPTB, a traceamine
receptor (TAAR1) antagonist, significantly antagonized the inhibitory effects of both Klamin®
and exogenous -PEA, suggesting a trace-amine involvement in the Klamin® effects. Accordingly,
AphaMax®, an AFA extract containing lesser amount of -PEA, failed to modify colon contractility.
Moreover, the Klamin® effects were abolished by tetrodotoxin, a neural blocker, but not by L-NAME,
a nitric oxide-synthase inhibitor. On the contrary methysergide, a serotonin receptor antagonist,
significantly antagonized the Klamin® effects, as well as the contractility reduction induced by 5-HT.
The RT-PCR analysis revealed TAAR1 gene expression in the colon and the IHC experiments showed
that 5-HT-positive neurons are co-expressed with TAAR1 positive neurons. In conclusion, the results
of this study suggest that Klamin® exerts spasmolytic effects in human colon contractility through
-PEA, that, by activating neural TAAR1, induce serotonin release from serotoninergic neurons of
the myenteric plexus
Using GENI for experimental evaluation of Software Defined Networking in smart grids
The North American Electric Reliability Corporation (NERC) envisions a smart grid that aggressively explores advance communication network solutions to facilitate real-time monitoring and dynamic control of the bulk electric power system. At the distribution level, the smart grid integrates renewable generation and energy storage mechanisms to improve the reliability of the grid. Furthermore, dynamic pricing and demand management provide customers an avenue to interact with the power system to determine the electricity usage that best satisfies their lifestyle. At the transmission level, efficient communication and a highly automated architecture provide visibility in the power system and as a result, faults are mitigated faster than they can propagate. However, such higher levels of reliability and efficiency rest on the supporting communication infrastructure. To date, utility companies are moving towards Multiprotocol Label Switching (MPLS) because it supports traffic engineering and virtual private networks (VPNs). Furthermore, it provides Quality of Service (QoS) guarantees and fail-over mechanisms in addition to meeting the requirement of non-routability as stipulated by NERC. However, these benefits come at a cost for the infrastructure that supports the fullMPLS specification. With this realization and given a two week implementation and deployment window in GENI, we explore the modularity and flexibility provided by the low cost OpenFlow Software Defined Networking (SDN) solution. In particular, we use OpenFlow to provide 1.) automatic fail-over mechanisms, 2.) a load balancing, and 3.) Quality of Service guarantees: all essential mechanisms for smart grid networks
Effect of a Klamath algae product ("AFA-B12") on blood levels of vitamin B12 and homocysteine in vegan subjects: a pilot study
none8Vitamin B12 is a critical nutrient that is often inadequate in a plant-based (vegan) diet, thus the inclusion of a reliable vitamin B12 source in a vegan diet is recommended as essential. Unfortunately, many natural sources of vitamin B12 have been proven to contain biologically inactive vitamin B12 analogues, inadequate for human supplementation. The aim of this non-randomized open trial was to determine whether supplementation with a natural Klamath algae-based product ("AFA-B12", Aphanizomenon flos-aquae algae plus a proprietary mix of enzymes) could favorably affect the vitamin B12 status of a group of 15 vegan subjects. By assessing blood concentration of vitamin B12, folate, and more importantly homocysteine (Hcy, a reliable marker in vegans of their B12 absorption), the vitamin B12 status of the participants at the end of the 3-month intervention period, while receiving the Klamath-algae supplement (T2), was compared with their vitamin B12 status at the end of the 3-month control period (T1), when they were not receiving any supplement, having stopped taking their usual vitamin B12 supplement at the beginning of the study (T0). Compared to the control period, in the intervention period participants improved their vitamin B12 status, significantly reducing Hcy blood concentration (p=0.003). In conclusion, the Klamath algae product AFA-B12 appears to be, in a preliminary study, an adequate and reliable source of vitamin B12 in humans.openL.Baroni; S.Scoglio; S.Benedetti; C.Bonetto; S.Pagliarani; Y.Benedetti; M.Rocchi; F.CanestrariL., Baroni; S., Scoglio; Benedetti, Serena; C., Bonetto; S., Pagliarani; Y., Benedetti; Rocchi, MARCO BRUNO LUIGI; Canestrari, Franc
Biologically Informed Individual-Based Network Model for Rift Valley Fever in the US and Evaluation of Mitigation Strategies
Citation: Scoglio, C. M., Bosca, C., Riad, M. H., Sahneh, F. D., Britch, S. C., Cohnstaedt, L. W., & Linthicum, K. J. (2016). Biologically Informed Individual-Based Network Model for Rift Valley Fever in the US and Evaluation of Mitigation Strategies. Plos One, 11(9), 26. doi:10.1371/journal.pone.0162759Rift Valley fever (RVF) is a zoonotic disease endemic in sub-Saharan Africa with periodic outbreaks in human and animal populations. Mosquitoes are the primary disease vectors; however, Rift Valley fever virus (RVFV) can also spread by direct contact with infected tissues. The transmission cycle is complex, involving humans, livestock, and multiple species of mosquitoes. The epidemiology of RVFV in endemic areas is strongly affected by climatic conditions and environmental variables. In this research, we adapt and use a network-based modeling framework to simulate the transmission of RVFV among hypothetical cattle operations in Kansas, US. Our model considers geo-located livestock populations at the individual level while incorporating the role of mosquito populations and the environment at a coarse resolution. Extensive simulations show the flexibility of our modeling framework when applied to specific scenarios to quantitatively evaluate the efficacy of mosquito control and livestock movement regulations in reducing the extent and intensity of RVF outbreaks in the United States
Epidemic and Cascading Survivability of Complex Networks
Our society nowadays is governed by complex networks, examples being the
power grids, telecommunication networks, biological networks, and social
networks. It has become of paramount importance to understand and characterize
the dynamic events (e.g. failures) that might happen in these complex networks.
For this reason, in this paper, we propose two measures to evaluate the
vulnerability of complex networks in two different dynamic multiple failure
scenarios: epidemic-like and cascading failures. Firstly, we present
\emph{epidemic survivability} (), a new network measure that describes the
vulnerability of each node of a network under a specific epidemic intensity.
Secondly, we propose \emph{cascading survivability} (), which characterizes
how potentially injurious a node is according to a cascading failure scenario.
Then, we show that by using the distribution of values obtained from and
it is possible to describe the vulnerability of a given network. We
consider a set of 17 different complex networks to illustrate the suitability
of our proposals. Lastly, results reveal that distinct types of complex
networks might react differently under the same multiple failure scenario
Measurements of the reaction of antiproton annihilation at rest at three hydrogen target densities
The proton-antiproton annihilation at rest into the final state
was measured for three different target densities: liquid hydrogen, gaseous
hydrogen at NTP and at a low pressure of 5 mbar. The yield of this reaction in
the liquid hydrogen target is smaller than in the low-pressure gas target. The
branching ratios of the channel were calculated on the basis of
simultaneous analysis of the three data samples. The branching ratio for
annihilation into from the protonium state turns out to be
about ten times smaller as compared to the one from the state.Comment: 10 pages, 3 Postscript figures. Accepted by Physics Letters
Five years of experience with the FiLaC™ laser for fistula-in-ano management: long-term follow-up from a single institution
Therapeutic immunization with HIV-1 Tat reduces immune activation and loss of regulatory T-cells and improves immune function in subjects on HAART.
Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4(+) T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks) on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002). Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002), served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4(+) and CD8(+) cellular activation (CD38 and HLA-DR) together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4(+) T cells and B cells with reduction of CD8(+) T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4(+) and CD8(+) T cells were accompanied by increases of CD4(+) and CD8(+) T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes were opposite, absent or partial in the OBS population. These findings support the use of Tat immunization to intensify HAART efficacy and to restore immune homeostasis. TRIAL REGISTRATION: ClinicalTrials.gov NCT00751595
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