Voting Behavior, Coalitions and Government Strength through a Complex Network Analysis

We analyze the network of relations between parliament members according to their voting behavior. In particular, we examine the emergent community structure with respect to political coalitions and government alliances. We rely on tools developed in the Complex Network literature to explore the core of these communities and use their topological features to develop new metrics for party polarization, internal coalition cohesiveness and government strength. As a case study, we focus on the Chamber of Deputies of the Italian Parliament, for which we are able to characterize the heterogeneity of the ruling coalition as well as parties specific contributions to the stability of the government over time. We find sharp contrast in the political debate which surprisingly does not imply a relevant structure based on establised parties. We take a closer look to changes in the community structure after parties split up and their effect on the position of single deputies within communities. Finally, we introduce a way to track the stability of the government coalition over time that is able to discern the contribution of each member along with the impact of its possible defection. While our case study relies on the Italian parliament, whose relevance has come into the international spotlight in the present economic downturn, the methods developed here are entirely general and can therefore be applied to a multitude of other scenarios.Comment: 6 pages, 4 figure

Memory effects in stock price dynamics: evidences of technical trading

Technical trading represents a class of investment strategies for Financial Markets based on the analysis of trends and recurrent patterns in price time series. According standard economical theories these strategies should not be used because they cannot be profitable. On the contrary, it is well-known that technical traders exist and operate on different time scales. In this paper we investigate if technical trading produces detectable signals in price time series and if some kind of memory effects are introduced in the price dynamics. In particular, we focus on a specific figure called supports and resistances. We first develop a criterion to detect the potential values of supports and resistances. Then we show that memory effects in the price dynamics are associated to these selected values. In fact we show that prices more likely re-bounce than cross these values. Such an effect is a quantitative evidence of the so-called self-fulfilling prophecy, that is the self-reinforcement of agents' belief and sentiment about future stock prices' behavior

Gold-Nanoparticle-Based Colorimetric Discrimination of Cancer-Related Point Mutations with Picomolar Sensitivity

Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification

Toxicity of citrate-capped AuNPs: an in vitro and in vivo assessment

In this study, we show that 15 nm citrate-capped AuNPs exert a remarkable toxicity in living systems. The assessment was performed by using well-characterized AuNPs, the combination of in vitro and in vivo models (namely two different cell lines and Drosophila melanogaster), exposure to low dosages of nanoparticles (in the sub-nanomolar concentration range), along with the application of several biological assays to monitor different aspects of the toxic effects, such as viability, genotoxicity, and molecular biomarkers

Effects of Cell Culture Media on the Dynamic Formation of Protein−Nanoparticle Complexes and Influence on the Cellular Response

The development of appropriate in vitro protocols to assess the potential toxicity of the ever expanding range of nanoparticles represents a challenging issue, because of the rapid changes of their intrinsic physicochemical properties (size, shape, reactivity, surface area, etc.) upon dispersion in biological fluids. Dynamic formation of protein coating around nanoparticles is a key molecular event, which may strongly impact the biological response in nanotoxicological tests. In this work, by using citrate-capped gold nanoparticles (AuNPs) of different sizes as a model, we show, by several spectroscopic techniques (dynamic light scattering, UV−visible, plasmon resonance light scattering), that proteins−NP interactions are differently mediated by two widely used cellular media (i.e., Dulbecco Modified Eagle's medium (DMEM) and Roswell Park Memorial Institute medium (RPMI), supplemented with fetal bovine serum). We found that, while DMEM elicits the formation of a large time-dependent protein corona, RPMI s..

Mutagenic effects of gold nanoparticles induce aberrant phenotypes in Drosophila melanogaster

Abstract The peculiar physical/chemical characteristics of engineered nanomaterials have led to a rapid increase of nanotechnology-based applications in many fields. However, before exploiting their huge and wide potential, it is necessary to assess their effects upon interaction with living systems. In this context, the screening of nanomaterials to evaluate their possible toxicity and understand the underlying mechanisms currently represents a crucial opportunity to prevent severe harmful effects in the next future. In this work we show the in vivo toxicity of gold nanoparticles (Au NPs) in Drosophila melanogaster , highlighting significant genotoxic effects and, thus, revealing an unsettling aspect of the long-term outcome of the exposure to this nanomaterial. After the treatment with Au NPs, we observed dramatic phenotypic modifications in the subsequent generations of Drosophila , demonstrating their capability to induce mutagenic effects that may be transmitted to the descendants. Noteworthy, we were able to obtain the first nanomaterial-mutated organism, named NM-mut. Although these results sound alarming, they underline the importance of systematic and reliable toxicology characterizations of nanomaterials and the necessity of significant efforts by the nanoscience community in designing and testing suitable nanoscale surface engineering/coating to develop biocompatible nanomaterials with no hazardous effects for human health and environment. From the Clinical Editor While the clinical application of nanomedicine is still in its infancy, the rapid evolution of this field will undoubtedly result in a growing number of clinical trials and eventually in human applications. The interactions of nanoparticles with living organisms determine their toxicity and long-term safety, which must be properly understood prior to large-scale applications are considered. The paper by Dr. Pompa's team is the first ever demonstration of mutagenesis resulting in clearly observable phenotypic alterations and the generation of nano-mutants as a result of exposure to citrate-surfaced gold nanoparticles in drosophila. These groundbreaking results are alarming, but represent a true milestone in nanomedicine and serve as a a reminder and warning about the critical importance of "safety first" in biomedical science

Monodispersed and size-controlled multibranched gold nanoparticles with nanoscale tuning of surface morphology

A novel seed-mediated synthetic route to produce multibranched gold nanoparticles is reported, in which it is possible to precisely tune both their size and nanostructuration, while maintaining an accurate level of monodispersion. The nanoscale control of surface nanoroughness/branching, ranging from small bud-like features to elongated spikes, allows to obtain fine tuning of the nanoparticle optical properties, up to the red and near-IR region of the spectrum. Such anisotropic nanostructures were demonstrated to be excellent candidates for SERS applications, showing significantly higher signals with respect to the standard spherical nanoparticles

In Vivo toxicity assessment of gold nanoparticles in Drosophila melanogaster

The growing use of nanomaterials in commercial goods and novel technologies is generating increasing questions about possible risks for human health and environment, due to the lack of an in-depth assessment of their potential toxicity. In this context, we investigated the effects of citrate-capped gold nanoparticles (AuNPs) on the model system Drosophila melanogaster upon ingestion. We observed a significant in vivo toxicity of AuNPs, which elicited clear adverse effects in treated organisms, such as a strong reduction of their life span and fertility, presence of DNA fragmentation, as well as a significant overexpression of the stress proteins. Transmission electron microscopy demonstrated the localization of the nanoparticles in tissues of Drosophila. The experimental evidence of high in vivo toxicity of a nanoscale material, which is widely considered to be safe and biocompatible in its bulk form, opens up important questions in many fields, including nanomedicine, material science, health, drug delivery and risk assessment

Framing the nano-biointeractions by proteomics

Knowledge of the molecular mechanisms underlying the interactions between nanomaterials and living systems is fundamental for providing more effective products for nanomedicine and drug delivery. Controlling the response of cells/bacteria (such as activation of inflammatory processes or apoptosis/necrosis in tumor cells or pathogenic bacteria) by tuning specific properties of the nanomaterials is ultimately the challenging goal. Notably, this may also provide crucial information in the assessment of any toxic risks induced by nanoparticles on humans. However, in studying the nano-biointeractions, it is imperative to take into account the dynamic evolutions of nanoparticles in the biological environments (in terms of protein corona formation, size and charge changes) in synergy with the dynamic events occurring in cells, including signal transduction, metabolic processes, homeostasis and membrane trafficking. In this context, we discuss the impact of analytical technologies, especially in the field of proteomics, which can provide major insights into the processes affecting the NPs surface as well as the cells and bacteria functionalities. In particular, we show that a precise control of the chemical-physical characteristics of the interacting nanoparticles or nanostructures may impact the cells by inducing changes in the proteomic profiles with direct consequences on their viability

Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: a retrospective study

BACKGROUND: The aim of this retrospective study was to evaluate the survival of dental implants placed after ablative surgery, in patients affected by oral cancer treated with or without radiotherapy. METHODS: We collected data for 34 subjects (22 females, 12 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and received dental implant rehabilitation between 2007 and 2012. Postoperative radiation therapy (less than 50 Gy) was delivered before implant placement in 12 patients. A total of 144 titanium implants were placed, at a minimum interval of 12 months, in irradiated and non-irradiated residual bone. RESULTS: Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on whether the patient had received radiotherapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determinin