A virtual platform for real-time performance analysis of electromagnetic tracking systems for surgical navigation

Electromagnetic Tracking Systems (EMTSs) are widely used in surgical navigation, allowing to improve the outcome of diagnosis and surgical interventions, by providing the surgeon with real-time position of surgical instruments during medical procedures. However, particular effort was dedicated to the development of efficient and robust algorithms, to obtain an accurate estimation of the instrument position for distances from the magnetic field generator beyond 0.5 m. Indeed, the main goal is to improve the limited range of current commercial systems, which strongly affects the freedom of movement of the medical team. Studies are currently being conducted to optimize the magnetic field generator configuration (both geometrical arrangements and electrical properties) since it affects tracking accuracy. In this paper, we propose a virtual platform for assessing the performance of EMTSs for surgical navigation, providing real-time results and statistics, and allowing to track instruments both in real and simulated environments. Simulations and experimental tests are performed to validate the proposed virtual platform, by employing it to assess the performance of a real EMTS. The platform offers a real-time tool to analyze EMTS components and field generator configurations, for a deeper understanding of EMTS technology, thus supporting engineers during system design and characterization.</p

Rivaroxaban for the treatment of noncirrhotic splanchnic vein thrombosis: an interventional prospective cohort study.

Heparins and vitamin K antagonists are the mainstay of treatment of splanchnic vein thrombosis (SVT). Rivaroxaban is a potential alternative, but data to support its use are limited. We aimed to evaluate the safety and efficacy of rivaroxaban for the treatment of acute SVT. In an international, single-arm clinical trial, adult patients with a first episode of noncirrhotic, symptomatic, objectively diagnosed SVT received rivaroxaban 15 mg twice daily for 3 weeks, followed by 20 mg daily for an intended duration of 3 months. Patients with Budd-Chiari syndrome and those receiving full-dose anticoagulation for &gt;7 days prior to enrollment were excluded. Primary outcome was major bleeding; secondary outcomes included death, recurrent SVT, and complete vein recanalization within 3 months. Patients were followed for a total of 6 months. A total of 103 patients were enrolled; 100 were eligible for the analysis. Mean age was 54.4 years; 64% were men. SVT risk factors included abdominal inflammation/infection (28%), solid cancer (9%), myeloproliferative neoplasms (9%), and hormonal therapy (9%); 43% of cases were unprovoked. JAK2 V617F mutation was detected in 26% of 50 tested patients. At 3 months, 2 patients (2.1%; 95% confidence interval, 0.6-7.2) had major bleeding events (both gastrointestinal). One (1.0%) patient died due to a non-SVT-related cause, 2 had recurrent SVT (2.1%). Complete recanalization was documented in 47.3% of patients. One additional major bleeding event and 1 recurrent SVT occurred at 6 months. Rivaroxaban appears as a potential alternative to standard anticoagulation for the treatment of SVT in non-cirrhotic patients. This trial was registered at www.clinicaltrials.gov as #NCT02627053 and at eudract.ema.europa.eu as #2014-005162-29-36

Data from: Directional postcopulatory sexual selection is associated with female sperm storage in Trinidadian guppies

Female sperm storage (FSS) is taxonomically widespread and often associated with intense sperm competition, yet its consequences on postcopulatory sexual selection (PCSS) are poorly known. Theory predicts that FSS will reduce the strength of PCSS, because sperm characteristics favored before and after FSS may be traded-off, and opportunities for nondirectional PCSS should increase. We explored these questions in the guppy (Poecilia reticulata), by allowing females to mate multiply and by comparing the paternity pattern in two successive broods. Contrary to predictions, the variance in male fertilization success increased after FSS, driven by a change in male paternity share across broods. This change was positively associated with sperm velocity (measured before FSS) but not with the duration of FSS, indirectly suggesting that faster sperm were better in entering female storage organs, rather than in persisting within them. Other male traits, such as male size and orange color, heterozygosity, and relatedness to the female, did not influence paternity after FSS. These results indicate that processes associated with FSS tend to reinforce the strength of PCSS in guppies, rather than weaken it. Further work is necessary to test whether this pattern changes in case of more prolonged FSS

Management of disseminated intravascular coagulation: A survey of the International Society on Thrombosis and Haemostasis

Introduction It is not clear if and how international guidelines on the management of disseminated intravascular coagulation (DIC) are translated in routine clinical practice. Materials and Methods A survey was conducted among different specialists who treat DIC. The survey examined six hypothetical case scenarios including the diagnosis of DIC, the treatment of non-overt and overt DIC with or without thrombosis, and the management of DIC patients at risk of bleeding or actively bleeding. Results There were 191 respondents and 73 returned complete questionnaires. Most of respondents were specialists in hematology (48%) or intensive care (30%). In suspected overt or non-overt DIC, only one third use formal diagnostic scores while two thirds rely on a broad panel of coagulation tests independently of any score. In non-overt DIC, 68% provide no treatment, but monitor laboratory tests. Monitoring was considered by 48% of respondents in overt DIC without thrombosis or bleeding. When a thrombotic or bleeding complication ensues, 29% consider intervening only if the event is major. In DIC patients judged at risk of bleeding, 67% use prophylactic transfusions, mostly fresh-frozen plasma (73%) and platelets (65%). Active bleeding is often managed with fresh-frozen plasma (83%) and platelet transfusions (68%) as first line and recombinant activated factor VII (31%) as second line treatment. Conclusions This survey shows a largely heterogeneous approach of clinicians to the diagnosis and management of DIC. There is limited use of diagnostic scores despite guidelines' recommendations. The prevalent attitude seems monitoring DIC and limiting treatment to the underlying disease, unless thrombosis or bleeding develop, but modalities varied considerably

Diagnosis of overt and non-overt disseminated intravascular coagulation: A survey among experts and a call for action from the ISTH

4sinonenoneSquizzato, Alessandro; Rancan, Elena; Thachil, Jecko; Di Nisio, MarcelloSquizzato, Alessandro; Rancan, Elena; Thachil, Jecko; Di Nisio, Marcell

Do Aging and Parity Affect VEGF-A/VEGFR Content and Signaling in the Ovary?—A Mouse Model Study

In this study, the effects of aging and parity on VEGF-A/VEGFR protein content and signaling in the mice ovaries were determined. The research group consisted of nulliparous (virgins, V) and multiparous (M) mice during late-reproductive (L, 9–12 months) and post-reproductive (P, 15–18 months) stages. Whilst ovarian VEGFR1 and VEGFR2 remained unchanged in all the experimental groups (LM, LV, PM, PV), protein content of VEGF-A and phosphorylated VEGFR2 significantly decreased only in PM ovaries. VEGF-A/VEGFR2-dependent activation of ERK1/2, p38, as well as protein content of cyclin D1, cyclin E1, and Cdc25A were then assessed. In ovaries of LV and LM, all of these downstream effectors were maintained at a comparable low/undetectable level. Conversely, the decrease recorded in PM ovaries did not occur in the PV group, in which the significant increase of kinases and cyclins, as well phosphorylation levels mirrored the trend of the pro-angiogenic markers. Altogether, the present results demonstrated that, in mice, ovarian VEGF-A/VEGFR2 protein content and downstream signaling can be modulated in an age- and parity-dependent manner. Moreover, the lowest levels of pro-angiogenic and cell cycle progression markers detected in PM mouse ovaries sustains the hypothesis that parity could exert a protective role by downregulating the protein content of key mediators of pathological angiogenesis

Endocannabinoid System Components of the Female Mouse Reproductive Tract Are Modulated during Reproductive Aging

The endocannabinoid (eCB) system has gained ground as a key modulator of several female fertility-related processes, under physiological/pathological conditions. Nevertheless, its modulation during reproductive aging remains unclear. This study aimed to investigate the expression levels of the main receptors (cannabinoid receptor 1,CB1; cannabinoid receptor 2, CB2; G-protein coupled receptor, GPR55; and transient receptor potential vanilloid type 1 channel, TRPV1) and metabolic enzymes (N-acylphosphatidylethanolamine phospholipase D, NAPE-PLD; fatty acid amide hydrolase, FAAH; monoacylglycerol lipase, MAGL; and diacylglycerol lipase, DAGL-α and -β) of this system in the ovaries, oviducts, and uteri of mice at prepubertal, adult, late reproductive, and post-reproductive stages through quantitative ELISA and immunohistochemistry. The ELISA showed that among the receptors, TRPV1 had the highest expression and significantly increased during aging. Among the enzymes, NAPE-PLD, FAAH, and DAGL-β were the most expressed in these organs at all ages, and increased age-dependently. Immunohistochemistry revealed that, regardless of age, NAPE-PLD and FAAH were mainly found in the epithelial cells facing the lumen of the oviduct and uteri. Moreover, in ovaries, NAPE-PLD was predominant in the granulosa cells, while FAAH was sparse in the stromal compartment. Of note, the age-dependent increase in TRPV1 and DAGL-β could be indicative of increased inflammation, while that of NAPE-PLD and FAAH could suggest the need to tightly control the levels of the eCB anandamide at late reproductive age. These findings offer new insights into the role of the eCB system in female reproduction, with potential for therapeutic exploitation

Multivariate selection drives concordant patterns of pre- and postcopulatory sexual selection in a livebearing fish

In many species, females mate with multiple partners, meaning that sexual selection on male traits operates across a spectrum that encompasses the competition for mates (that is, before mating) and fertilizations (after mating). Despite being inextricably linked, pre- and postcopulatory sexual selection are typically studied independently, and we know almost nothing about how sexual selection operates across this divide. Here we bridge this knowledge gap using the livebearing fish Poecilia reticulata. We show that both selective episodes, as well as their covariance, explain a significant component of variance in male reproductive fitness. Moreover, linear and nonlinear selection simultaneously act on pre- and postcopulatory traits, and interact to generate multiple phenotypes with similar fitness

Enea e Turno; il paesaggio del mito tra geologia ed archeologia

Il territorio del litorale romano che si sviluppa tra la foce del Tevere, il Fosso dell’Incastro e il complesso vulcanico dei Colli Albani, è ricchissimo di testimonianze archeologiche associate in modo più o meno diretto al mito di Enea e del suo avversario Turno, semidei le cui gesta sono celebrate nei classici ed in particolare dalla narrazione virgiliana voluta da Ottaviano Augusto. Questo paesaggio, agli albori della storia arcaica di Roma, era molto diverso dall’attuale, caratterizzato da un ampio sistema di lagune costiere in comunicazione con il mare aperto, ove confluivano quei corsi d’acqua che, dalle pendici dei Colli Albani, giungono direttamente al Tirreno, costituendo luoghi ideali presso cui rappresentare l’approdo dei tanti “eroi venuti dal mare”, che dalla Grecia e dall’Asia minore, risalivano la costa alla ricerca dei preziosi metalli dell’Etruria e dell’Isola d’Elba. Il riconoscimento di una ‘geografia’ troiana a Lavinium, in pieno accordo con le fonti antiche, è delineato dall’identificazione di un grande santuario costiero, il locus Solis Indigetis richiamato dalle fonti presso il fiume Numicus (corrispondente all’attuale fosso di Pratica). Il mito di Turno invece si sviluppa intorno all’antichissima città di Ardea e al santuario arcaico, in seguito fortificato, presso il fosso dell’Incastro di Ardea, attribuito al Castrum Inui delle fonti, in pendant con quello lavinate. I miti di Enea, Turno e i vari personaggi narrati da Virgilio sono associati in modo indissolubile al paesaggio geologico di questo straordinario territorio, non a caso proposto quale contesto qualificato per l’istituzione di un parco virgiliano