Internally positive representations and stability analysis of linear delay systems with multiple time-varying delays

This chapter introduces the Internally Positive Representation of linear systems with multiple time-varying state delays. The technique, previously introduced for the undelayed case, aims at building a positive representation of systems whose dynamics is, in general, indefinite in sign. As a consequence, stability criteria for positive time-delay systems can be exploited to analyze the stability of the original system. As a result, an easy-to-check sufficient condition for the delay-independent stability is provided, that is compared with some well known conditions available in the literature

A case report of myoid gonadal stromal tumor treated with testis sparing surgery

Background: Myoid gonadal stromal tumors (MGST) of the testis represent a very rare finding. They are an emerging clinicopathological entity with specific features and identity. Nowadays, pathological recognition and diagnosis of MGSTs still represents a difficult challenge in most cases and there are no data of specific radiological features of these tumors expect for what seen by ultrasound; besides a conservative surgical approach was never performed to treat these lesions.Case Description: We present the case of a 20-year-old young man patient with symptoms suspicious for left varicocele, who was incidentally diagnosed with right testicular nodule via scrotal doppler ultrasound powered with contrast enhancement infusion and subsequent multiparametric magnetic resonance imaging. Then, lesion was treated through a testis sparing surgical approach. Histopathology, which included an external revision by an experienced Center, revealed a MGST with benign features, so that no further treatment was considered. 3 and 12 months after surgery a contrast enhancement ultrasound was performed with no evidence of recurrence.Conclusions: Previous reported cases of MGST were all difficult to characterize as a specific pathological entity; treatment usually applied was radical orchiectomy and a subsequent total Body CT was performed for staging purpose. No metastatic spreading nor recurrence were ever reported. Considering the favorable behavior of this pathologic entity, testis-sparing surgery with no radiation exposure during follow-up is a safe and effective strategy

The ACCENT-VOCBAS field campaign on biosphere-atmosphere interactions in a Mediterranean ecosystem of Castelporziano (Rome): site characteristics, climatic and meteorological conditions, and eco-physiology of vegetation

Biosphere-atmosphere interactions were investigated on a sandy dune Mediterranean ecosystem in a field campaign held in 2007 within the frame of the European Projects ACCENT and VOCBAS. The campaign was carried out in the Presidential estate of Castelporziano, a periurban park close to Rome. Former campaigns (e.g. BEMA) performed in Castelporziano investigated the emission of biogenic volatile organic compounds (BVOC). These campaigns focused on pseudosteppe and evergreen oak groves whereas the contribution of the largely biodiverse dune vegetation, a prominent component of the Mediterranean ecosystem, was overlooked. While specific aspects of the campaign will be discussed in companion papers, the general climatic and physiological aspects are presented here, together with information regarding BVOC emission from the most common plant species of the dune ecosystem. During the campaign regular air movements were observed, dominated by moderate nocturnal land breeze and diurnal sea breeze. A regular daily increase of ozone concentration in the air was also observed, but daily peaks of ozone were lower than those measured in summer on the same site. The site was ideal as a natural photochemical reactor to observe reaction, transport and deposition processes occurring in the Mediterranean basin, since the sea-land breeze circulation allowed a strong mixing between biogenic and anthropogenic emissions and secondary pollutants. Measurements were run in May, when plant physiological conditions were optimal, in absence of severe drought and heat stress. Foliar rates of photosynthesis and transpiration were as high as generally recorded in unstressed Mediterranean sclerophyllous plants. Most of the plant species emitted high level of monoterpenes, despite measurements being made in a period in which emissions of volatile isoprenoids could be restrained by developmental and environmental factors, such as leaf age and relatively low air temperature. Emission of isoprene was generally low. Accounting for the high monoterpene spring emission of the dune ecosystem may be important to correct algorithms at regional and ecosystem levels, and to interpret measurements of fluxes of volatile isoprenoids and secondary pollutants

Frailty Network in an Acute Care Setting: The New Perspective for Frail Older People

The incidence of elderly patients who come to the emergency room is progressively increasing. The specialization of the physician units might not be adequate for the evaluation of this complexity. The present study aimed to present a standard procedure, called ‘The Geriatric Frailty Network’, operating at the Policlinico Gemelli IRCCS Foundation, which is configured specifically for the level II assessment of frail elderly patients. This was a retrospective study in 1191 patients aged over 65, who were evaluated by the Geriatric Frailty Unit directly after emergency department admission for one year. All patients underwent multidimensional geriatric evaluation. Data were collected on demographics, co-morbidity, disease severity, and Clinical Frailty Scale. Among all patients, 723 were discharged directly from the emergency room with early identification of continuity of care path. Globally, 468 patients were hospitalized with an early assessment of frailty that facilitated the discharge process. The geriatric frailty network model aims to assist the emergency room and ward doctor in the prevention of the most common geriatric syndromes and reduce the number of incongruous hospitalization

Exposure to Residential Greenness as a Predictor of Cause-Specific Mortality and Stroke Incidence in the Rome Longitudinal Study.

BACKGROUND: Living in areas with higher levels of surrounding greenness and access to urban green areas have been associated with beneficial health outcomes. Some studies suggested a beneficial influence on mortality, but the evidence is still controversial. OBJECTIVES: We used longitudinal data from a large cohort to estimate associations of two measures of residential greenness exposure with cause-specific mortality and stroke incidence. METHODS: We studied a population-based cohort of 1,263,721 residents in Rome aged [Formula: see text], followed from 2001 to 2013. As greenness exposure, we utilized the leaf area index (LAI), which expresses the tree canopy as the leaf area per unit ground surface area, and the normalized difference vegetation index (NDVI) within 300- and [Formula: see text] buffers around home addresses. We estimated the association between the two measures of residential greenness and the outcomes using Cox models, after controlling for relevant individual covariates and contextual characteristics, and explored potential mediation by air pollution [fine particulate matter with aerodynamic diameter [Formula: see text] [Formula: see text] and [Formula: see text]] and road traffic noise. RESULTS: We observed 198,704 deaths from nonaccidental causes, 81,269 from cardiovascular diseases [CVDs; 29,654 from ischemic heart disease (IHD)], 18,090 from cerebrovascular diseases, and 29,033 incident cases of stroke. Residential greenness, expressed as interquartile range (IQR) increase in LAI within [Formula: see text], was inversely associated with stroke incidence {hazard ratio (HR) 0.977 [95% confidence interval (CI): 0.961, 0.994]} and mortality for nonaccidental [HR 0.988 (95% CI: 0.981, 0.994)], cardiovascular [HR 0.984 (95% CI: 0.974, 0.994)] and cerebrovascular diseases [HR 0.964 (95% CI: 0.943, 0.985)]. Similar results were obtained using NDVI with 300- or [Formula: see text] buffers. CONCLUSIONS: Living in greener areas was associated with better health outcomes in our study, which could be partly due to reduced exposure to environmental hazards. Further research is required to understand the underlying mechanisms. https://doi.org/10.1289/EHP2854

Therapeutic alternatives in chronic thromboembolic pulmonary hypertension: from pulmonary endarterectomy to balloon pulmonary angioplasty to medical therapy. State of the art from a multidisciplinary team

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease with a very complex pathophysiology differing from other causes of pulmonary hypertension (PH). It is an infrequent consequence of acute pulmonary embolism that is frequently misdiagnosed. Pathogenesis has been related to coagulation abnormalities, infection or inflammation, although these disturbances can be absent in many cases. The hallmarks of CTEPH are thrombotic occlusion of pulmonary vessels, variable degree of ventricular dysfunction and secondary microvascular arteriopathy. The definition of CTEPH also includes an increase in mean pulmonary arterial pressure of more than 25 mmHg with a normal pulmonary capillary wedge of less than 15 mmHg. It is classified as World Health Organization group 4 PH, and is the only type that can be surgically cured by pulmonary endarterectomy (PEA). This operation needs to be carried out by a team with strong expertise, from the diagnostic and decisional pathway to the operation itself. However, because the disease has a very heterogeneous phenotype in terms of anatomy, degree of PH and the lack of a standard patient profile, not all cases of CTEPH can be treated by PEA. As a result, PH-directed medical therapy traditionally used for the other types of PH has been proposed and is utilized in CTEPH patients. Since 2015, we have been witnessing the rebirth of balloon pulmonary angioplasty, a technique first performed in 2001 but has since fallen out fashion due to major complications. The refinement of such techniques has allowed its safe utilization as a salvage therapy in inoperable patients. In the present keynote lecture, we will describe these therapeutic approaches and results

A generalization of the Virasoro algebra to arbitrary dimensions

Colored tensor models generalize matrix models in higher dimensions. They admit a 1/N expansion dominated by spherical topologies and exhibit a critical behavior strongly reminiscent of matrix models. In this paper we generalize the colored tensor models to colored models with generic interaction, derive the Schwinger Dyson equations in the large N limit and analyze the associated algebra of constraints satisfied at leading order by the partition function. We show that the constraints form a Lie algebra (indexed by trees) yielding a generalization of the Virasoro algebra in arbitrary dimensions