4,783 research outputs found
Non-systemic transmission of tick-borne diseases: a network approach
Tick-Borne diseases can be transmitted via non-systemic (NS) transmission.
This occurs when tick gets the infection by co-feeding with infected ticks on
the same host resulting in a direct pathogen transmission between the vectors,
without infecting the host. This transmission is peculiar, as it does not
require any systemic infection of the host. The NS transmission is the main
efficient transmission for the persistence of the Tick-Borne Encephalitis virus
in nature. By describing the heterogeneous ticks aggregation on hosts through a
\hyphenation{dynamical} bipartite graphs representation, we are able to
mathematically define the NS transmission and to depict the epidemiological
conditions for the pathogen persistence. Despite the fact that the underlying
network is largely fragmented, analytical and computational results show that
the larger is the variability of the aggregation, and the easier is for the
pathogen to persist in the population.Comment: 15 pages, 4 figures, to be published in Communications in Nonlinear
Science and Numerical Simulatio
The role of renal transporters and novel regulatory interactions in the TAL that control blood pressure
Hypertension (HTN), a major public health issue is currently the leading factor in the global burden of disease, where associated complications account for 9.4 million deaths worldwide every year (98). Excessive dietary salt intake is among the environmental factors that contribute to HTN, known as salt sensitivity. The heterogeneity of salt sensitivity and the multiple mechanisms that link high salt intake to increases in blood pressure are of upmost importance for therapeutic application. A continual increase in the kidney's reabsorption of sodium (Na+) relies on sequential actions at various segments along the nephron. When the distal segments of the nephron fail to regulate Na+, the effects on Na+ homeostasis are unfavourable. We propose that the specific nephron region where increased active uptake occurs as a result of variations in Na+ reabsorption is at the thick ascending limb of the loop of Henle (TAL). The purpose of this review is to urge the consideration of the TAL that contributes to the pathophysiology of salt sensitive HTN. Further research in this area will enable development of a therapeutic application for targeted treatment
Spontaneous emission of an atom near an oscillating mirror
We investigate the spontaneous emission of one atom placed near an oscillating reflecting plate. We consider the atom modeled as a two-level system, interacting with the quantum electromagnetic field in the vacuum state, in the presence of the oscillating mirror. We suppose that the plate oscillates adiabatically, so that the time-dependence of the interaction Hamiltonian is entirely enclosed in the time-dependent mode functions, satisfying the boundary conditions at the plate surface, at any given time. Using time-dependent perturbation theory, we evaluate the transition rate to the ground-state of the atom, and show that it depends on the time-dependent atom-plate distance. We also show that the presence of the oscillating mirror significantly affects the physical features of the spontaneous emission of the atom, in particular the spectrum of the emitted radiation. Specifically, we find the appearance of two symmetric lateral peaks in the spectrum, not present in the case of a static mirror, due to the modulated environment. The two lateral peaks are separated from the central peak by the modulation frequency, and we discuss the possibility to observe them with actual experimental techniques of dynamical mirrors and atomic trapping. Our results indicate that a dynamical (i.e., time-modulated) environment can give new possibilities to control and manipulate also other radiative processes of two or more atoms or molecules nearby, for example their cooperative decay or the resonant energy transfer
Analytical computation of the epidemic threshold on temporal networks
The time variation of contacts in a networked system may fundamentally alter
the properties of spreading processes and affect the condition for large-scale
propagation, as encoded in the epidemic threshold. Despite the great interest
in the problem for the physics, applied mathematics, computer science and
epidemiology communities, a full theoretical understanding is still missing and
currently limited to the cases where the time-scale separation holds between
spreading and network dynamics or to specific temporal network models. We
consider a Markov chain description of the Susceptible-Infectious-Susceptible
process on an arbitrary temporal network. By adopting a multilayer perspective,
we develop a general analytical derivation of the epidemic threshold in terms
of the spectral radius of a matrix that encodes both network structure and
disease dynamics. The accuracy of the approach is confirmed on a set of
temporal models and empirical networks and against numerical results. In
addition, we explore how the threshold changes when varying the overall time of
observation of the temporal network, so as to provide insights on the optimal
time window for data collection of empirical temporal networked systems. Our
framework is both of fundamental and practical interest, as it offers novel
understanding of the interplay between temporal networks and spreading
dynamics.Comment: 22 pages, 6 figure
Dirty Recycling: Auto Salvage and Its Potential Impacts on Marginalized Populations
The salvage yard represents the final waypoint in the cradle-to-grave cycle of the automobile. Residual amounts of petroleum hydrocarbons, heavy metals, and acids used in automobiles can be extremely harmful to human health and the environment if not managed correctly. The purpose of this study was to assess the extent to which minority populations were exposed to the hazards of the auto salvage industry. Census data for population, income, race/ethnicity, sex, and age were organized using ArcGIS software. Population demographics were analyzed in the areas surrounding 98 auto salvage yards found in Philadelphia and Adams Counties, Pennsylvania. In Philadelphia County, the results showed that low-income minorities, females, and 65+ individuals are over represented groups near auto salvage yards. Conversely, Adams County showed few spatial relationships in demographic distribution. Our findings suggest that in urban counties, such as Philadelphia, depressed property values have resulted in a large percentage of below average income minorities inhabiting areas in close proximity to auto salvage yards. On the other hand, auto salvage yards in rural areas, such as Adams County, do not appear to have the same effect because population density and racial diversity are much lower
Crimen calumniae and procedure ex officio in the canonist between XII and XIII century
Nell’ordinamento giudiziario penalistico a carattere prettamente accusatorio, qual è quello ancora operante in epoca medievale, la repressione del crimen calumniae e dei reati compiuti dall’accusator in sede processuale ha sempre costituito un potente deterrente contro un’utilizzazione strumentale del processo. Il Decretum di Graziano recepisce una parte fondamentale della normativa giustinianea prevista a carico di questo reato, determinando, su alcune tematiche, notevoli affinità nel pensiero dei civilisti e canonisti dell’epoca. Tale normativa prevedeva per la repressione del reato un procedimento a carattere prettamente inquisitorio: il giudice titolare del processo principale, infatti, una volta accertata l’infondatezza dell’accusa originaria poteva perseguire ex officio l’illecito di calumnia immediatamente e nell’ambito del medesimo giudizio. Quando, perciò, Innocenzo III introdurrà il procedimento inquisitorio nel processo penale canonico gli esegeti di questa Scuola ne conoscevano già la vigenza e l’utilizzazione per il particolare caso della calumnia.In the judicial order of criminal law of a purely accusing kind, which is still operating in medieval times, the repression of the crimen calumniae and of the offences made by the accuser in court has always constituted a powerful deterrent against an instrumental use of the trial. The Decretum of Graziano transposes a fundamental part of the law of Giustiniano envisaged for this offence, determining, on some issues, considerable affinity in the thought of the civilists and canonists of the time. This legislation provided for the repression of the offence a purely inquisitorial procedure: the judge holding the main proceedings, in fact, once ascertained that the original accusation was unsubstantiated, could prosecute ex officio the tort of calumnia immediately within the same judgement. When, therefore, Innocent III will introduce the inquisitorial procedure in the canonical penal process, the exegetes of this School already knew the validity and use for the particular case of calumnia.Ciencias ReligiosasDerech
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