Gravitational waves emitted by extrasolar planetary systems

In this paper we consider the Extra-solar Planetary Systems recently discovered in our Galaxy as potential sources of gravitational waves. We estimate the frequency and characteristic amplitude of the radiation they emit due to the orbital motion, using the quadrupole formalism. In addition, we check whether the conditions needed for the resonant excitation of the f- and g-modes of the central star can be fulfilled. By a Roche-lobe analysis, we show that there could exist systems in which the low-order g-modes could be excited, although this does not happen in the systems discovered up to now.Comment: 14 pages, 5 figures. Accepted for publication on International Journal of Modern Physics D. Table 6 and minor typos correcte

Compressing phase space detects state changes in nonlinear dynamical systems

Equations governing the nonlinear dynamics of complex systems are usually unknown and indirect methods are used to reconstruct their manifolds. In turn, they depend on embedding parameters requiring other methods and long temporal sequences to be accurate. In this paper, we show that an optimal reconstruction can be achieved by lossless compression of system's time course, providing a self-consistent analysis of its dynamics and a measure of its complexity, even for short sequences. Our measure of complexity detects system's state changes such as weak synchronization phenomena, characterizing many systems, in one step, integrating results from Lyapunov and fractal analysis.Comment: 6 pages, 3 figure

Effectiveness of dismantling strategies on moderated vs. unmoderated online social platforms

Online social networks are the perfect test bed to better understand large-scale human behavior in interacting contexts. Although they are broadly used and studied, little is known about how their terms of service and posting rules affect the way users interact and information spreads. Acknowledging the relation between network connectivity and functionality, we compare the robustness of two different online social platforms, Twitter and Gab, with respect to dismantling strategies based on the recursive censor of users characterized by social prominence (degree) or intensity of inflammatory content (sentiment). We find that the moderated (Twitter) vs unmoderated (Gab) character of the network is not a discriminating factor for intervention effectiveness. We find, however, that more complex strategies based upon the combination of topological and content features may be effective for network dismantling. Our results provide useful indications to design better strategies for countervailing the production and dissemination of anti-social content in online social platforms

Postoperative delirium in kidney transplant patients

Delirium, also known as acute brain failure, is a medical condition characterized by recent onset of confusion, fluctuating awareness, disorganized thought, with memory and attention impairment. Post-operative delirium (POD) generally arises 1 to 3 days after surgery, in 25-37% of the hospitalized patients and in > 65% of those admitted to intensive care unit [1]

Identification of genes involved in the drought adaptation and recovery in Portulaca oleracea by differential display

Portulaca oleracea is one of the richest plant sources of ω-3 and ω-6 fatty acids and other compounds potentially valuable for nutrition. It is broadly established in arid, semiarid and well-watered fields, thus making it a promising candidate for research on abiotic stress resistance mechanisms. It is capable of withstanding severe drought and then of recovering upon rehydration. Here, the adaptation to drought and the posterior recovery was evaluated at transcriptomic level by differential display validated by qRT-PCR. Of the 2279 transcript-derived fragments amplified, 202 presented differential expression. Ninety of them were successfully isolated and sequenced. Selected genes were tested against different abiotic stresses in P.oleracea and the behavior of their orthologous genes in Arabidopsis thaliana was also explored to seek for conserved response mechanisms. In drought adapted and in recovered plants changes in expression of many protein metabolism-, lipid metabolism- and stress-related genes were observed. Many genes with unknown function were detected, which also respond to other abiotic stresses. Some of them are also involved in the seed desiccation/imbibition process and thus would be of great interest for further research. The potential use of candidate genes to engineer drought tolerance improvement and recovery is discussed.Fil: D'andrea, Rodrigo Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; ArgentinaFil: Triassi, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; ArgentinaFil: Casas, María Isabel. Ohio State University; Estados UnidosFil: Andreo, Carlos Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; ArgentinaFil: Lara, Maria Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro de Estudios Fotosintéticos y Bioquímicos. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Centro de Estudios Fotosintéticos y Bioquímicos; Argentin

Laparoscopic repair for perforated peptic ulcer: our experience, a comparison with the open approach and a review of the literature.

Backgrounds: The incidence of perforated peptic ulcers has decreased during the last decades but the optimal treatment for these patients remains controversial. At the same time, a laparoscopic approach to this condition has been adopted by an increased number of surgeons. Therefore, this study wants to evaluate the postoperative results of the laparoscopic treatment of perforated peptic ulcer performed in one Italian center with extensive experience in laparoscopic surgery. Methods: This retrospective study includes 94 patients who were operated for perforated peptic ulcer peritonitis at “St. Orsola Hospital - Emergency Surgery Unit - University of Bologna” from May 2014 to December 2019. The patients’ charts were reviewed for demographics, surgical procedure, complications, and short-term outcomes. Results: The diagnosis was made clinically and confirmed by the presence of gas under diaphragm on abdominal X-ray. All patients underwent primary suture repair with or without omentopexy. Boey score 0 or 1 was found in 66 (70%) patients, Boey 2 or 3 in 28 (30%) patients. The operative time was between 35 and 255 minutes, with a mean of 93 minutes. The overall median hospital stay was 9.5 (1-60) days. Post-operative complications occurred in 19 (20%) patients and 18 (19%) patients died. Conclusions: Perforated peptic ulcer is a severe condition that requires early hospital admission and immediate surgery. Laparoscopy in experienced centers and for selected patients is safe, associated with optimal outcomes and should be the preferred approach

Laparoscopic repair for perforated peptic ulcer: Our experience, a comparison with the open approach and a review of the literature.

Background: The incidence of perforated peptic ulcers has decreased during the last decades but the optimal treatment for these patients remains controversial. At the same time, a laparoscopic approach to this condition has been adopted by an increased number of surgeons. Therefore, this study wants to evaluate the postoperative results of the laparoscopic treatment of perforated peptic ulcer performed in one Italian center with extensive experience in laparoscopic surgery. Methods: This retrospective study includes 94 patients who were operated for perforated peptic ulcer peritonitis at “St. Orsola Hospital - Emergency Surgery Unit - University of Bologna” from May 2014 to December 2019. The patients’ charts were reviewed for demographics, surgical procedure, complications, and short-term outcomes. Results: The diagnosis was made clinically and confi rmed by the presence of gas under diaphragm on abdominal X-ray. All patients underwent primary suture repair with or without omentopexy. Boey score 0 or 1 was found in 66 (70%) patients, Boey 2 or 3 in 28 (30%) patients. The operative time was between 35 and 255 minutes, with a mean of 93 minutes. The overall median hospital stay was 9.5 (1-60) days. Post-operative complications occurred in 19 (20%) patients and 18 (19%) patients died. Conclusions: Perforated peptic ulcer is a severe condition that requires early hospital admission and immediate surgery. Laparoscopy in experienced centers and for selected patients is safe, associated with optimal outcomes and should be the preferred approach

Synthesis and Biological Evaluation of New Glycoconjugated LDH Inhibitors as Anticancer Agents

Conjugation of known biologically active molecules to carbohydrate frameworks represents a valuable option for the preparation of hybrid, structurally-related families of compounds with the aim of modulating their biological response. Therefore, we present here a study on the preparation of d-galacto, d-manno, d-gluco, and d-lactose glycoconjugates of an established N-hydroxyindole-based (NHI) inhibitor of lactated dehydrogenase (LDH). Structural variations involved the sugar stereochemistry and size as well as the anchoring point of the NHI on the carbohydrate frame (either C-1 or C-6). In the case of the galactose anomeric glycoconjugate (C-1), intriguing solvent-dependent eects were observed in the glycosylation stereochemical outcome. The biological activity of the deprotected glycoconjugates in contrasting lactate formation and cancer cell proliferation are described

Estimating SARS-CoV-2 transmission in educational settings: a retrospective cohort study

Background School closures and distance learning have been extensively adopted to counter the COVID-19 pandemic. However, the contribution of school transmission to the spread of SARS-CoV-2 remains poorly quantified. Methods We analyzed transmission patterns associated with 976 SARS-CoV-2 exposure events, involving 460 positive individuals, as identified in early 2021 through routine surveillance and an extensive screening conducted on students, school personnel, and their household members in a small Italian municipality. In addition to population screenings and contact-tracing operations, reactive closures of class and schools were implemented. Results From the analysis of 152 clear infection episodes and 584 exposure events identified by epidemiological investigations, we estimated that approximately 50%, 21%, and 29% of SARS-CoV-2 transmission was associated with household, school, and community contacts, respectively. We found substantial transmission heterogeneities, with 20% positive individuals causing 75% to 80% of ascertained infection episodes. A higher proportion of infected individuals causing onward transmission was found among students (46.2% vs. 25%, on average), who also caused a markedly higher number of secondary cases (mean: 1.03 vs. 0.35). By reconstructing likely transmission chains from the entire set of exposures identified during contact-tracing operations, we found that clusters originated from students or school personnel were associated with a larger average cluster size (3.32 vs. 1.15) and a larger average number of generations in the transmission chain (1.56 vs. 1.17). Conclusions Uncontrolled SARS-CoV-2 transmission at school could disrupt the regular conduct of teaching activities, likely seeding the transmission into other settings, and increasing the burden on contact-tracing operations

Estimating SARS-CoV-2 transmission in educational settings: a retrospective cohort study

Background School closures and distance learning have been extensively adopted to counter the COVID-19 pandemic. However, the contribution of school transmission to the spread of SARS-CoV-2 remains poorly quantified. Methods We analyzed transmission patterns associated with 976 SARS-CoV-2 exposure events, involving 460 positive individuals, as identified in early 2021 through routine surveillance and an extensive screening conducted on students, school personnel, and their household members in a small Italian municipality. In addition to population screenings and contact-tracing operations, reactive closures of class and schools were implemented. Results From the analysis of 152 clear infection episodes and 584 exposure events identified by epidemiological investigations, we estimated that approximately 50%, 21%, and 29% of SARS-CoV-2 transmission was associated with household, school, and community contacts, respectively. We found substantial transmission heterogeneities, with 20% positive individuals causing 75% to 80% of ascertained infection episodes. A higher proportion of infected individuals causing onward transmission was found among students (46.2% vs. 25%, on average), who also caused a markedly higher number of secondary cases (mean: 1.03 vs. 0.35). By reconstructing likely transmission chains from the entire set of exposures identified during contact-tracing operations, we found that clusters originated from students or school personnel were associated with a larger average cluster size (3.32 vs. 1.15) and a larger average number of generations in the transmission chain (1.56 vs. 1.17). Conclusions Uncontrolled SARS-CoV-2 transmission at school could disrupt the regular conduct of teaching activities, likely seeding the transmission into other settings, and increasing the burden on contact-tracing operations