Optimising the observation of optical kilonovae with medium size telescopes

We consider the optimisation of the observing strategy (cadence, exposure time and filter choice) using medium size (2-m class) optical telescopes in the follow-up of kilonovae localised with arcminute accuracy to be able to distinguish among various kilonova models and viewing angles. To develop an efficient observation plan, we made use of the synthetic light curves obtained with the Monte Carlo radiative transfer code POSSIS for different kilonova models and as a function of different viewing angles and distances. By adding the appropriate photon counting noise to the synthetic light curves, we analysed four alternative sequences having the same total time exposure of 8 hours, with different time windows (0.5, 1, 2, 4 h), each with $i$, $r$, and $u$ filters, to determine the observing sequence that maximises the chance of a correct identification of the model parameters. We suggest to avoid $u$ filter and to avoid the use of colour curves. We also found that, if the error on distance is $\le$ 2%, 0.5, 1, 2-hour time window sequences are equivalent, so we suggest to use 2-hour one, because it has 1 day cadence, so it can be easily realised. When the distance of the source is unknown, 0.5 h time window sequence is preferable.Comment: 9 pages, 8 figures, published in MNRA

Copper-modified carbon nano-onions as electrode modifiers for the electroanalysis of the antiretroviral drug Efavirenz

The high prescription and consumption rate of antiretroviral drugs (ARV) such as Efavirenz (EFV) in South Africa for the treatment of the human immunodeficiency virus (HIV) has resulted in its presence in wastewater and surface water. Herein we report the electroanalysis of EFV at oxidised boron-nitrogen doped carbon nano-onions (oxi-BNCNO) and microscale branched copper cluster (CuC) modified glassy carbon electrodes. Potentiostatic electrodeposition of CuC on the oxi-BNCNO/GCE platform resulted in a stable and electrocatalytic surface that accelerated electron transfer between the analyte and the CuC/oxi-BNCNO/GCE surface, making quantification efficient. The electroactive surface area of CuC/oxi-BNCNO/GCE was estimated as being 3 times higher than bare GCE and twice that of oxi-BNCNO/GCE. The electrooxidation of EFV on a CuC/oxi-BNCNO/GCE sensor resulted in a pH-dependant anodic peak in the potential range of 0.8 to 1.2 V vs Ag/AgCl (3M KCl). The EFV voltammetric signal increased linearly with increasing concentration of EFV in the linear dynamic range (LDR) of 0.01 – 1.0 µM and 0.5 – 20 µM with a limit of detection (LOD) and quantification (LOQ) of 1.2 and 3.97 nM, respectively. Moreover, the sensor had a sensitivity of 23 µA • cm− 2 • µM− 1 and was selective to 100-fold of interferents including heavy metal ions and other ARVs with the exception of high concentrations of nevirapine. The developed electroanalytical method was successfully applied for the determination of EFV in real samples such as wastewater influent and effluent, drinking/tap water, and a pharmaceutical formulation with recovery ranging from 97.8% to 109.5%

GRB minimum variability timescale with Insight-HXMT and Swift: implications for progenitor models, dissipation physics and GRB classifications

The dissipation process of GRB prompt emission is still unknown. Study of temporal variability may provide a unique way to discriminate the imprint of the inner engine activity from geometry and propagation related effects. We define the minimum variability timescale (MVT) as the shortest duration of individual pulses that shape a light curve for a sample of GRBs and test correlations with peak luminosity, Lorentz factor, and jet opening angle. We compare these correlations with predictions from recent numerical simulations for a relativistic structured -- possibly wobbling -- jet and assess the value of MTV as probe of prompt-emission physics. We used the peak detection algorithm mepsa to identify the shortest pulse within a GRB time history and estimate its full width half maximum (FWHM). We applied this framework to two sets of GRBs: Swift (from 2005 to July 2022) and Insight-HXMT (from June 2017 to July 2021, including 221009A). We then selected 401 GRBs with measured z to test for correlations. On average short GRBs have significantly shorter MVT than long GRBs. The MVT distribution of short GRBs with extended emission such as 060614 and 211211A is compatible only with that of short GRBs. This provides a new clue on the progenitor's nature. The MVT for long GRBs anticorrelates with peak luminosity. We confirm the anticorrelation with the Lorentz factor and find a correlation with the jet opening angle as estimated from the afterglow, along with an inverse correlation with the number of pulses. The MVT can identify the emerging putative new class of long GRBs that are suggested to be produced by compact binary mergers. For otherwise typical long GRBs, the different correlations between MVT and peak luminosity, Lorentz factor, jet opening angle, and number of pulses can be explained within the context of structured, possibly wobbling, weakly magnetised relativistic jets. (summarised)Comment: 18 pages, 15 figures, accepted by A&

Identification of thyroid tumor cell vulnerabilities through a siRNA-based functional screening

The incidence of thyroid carcinoma is rapidly increasing. Although generally associated with good prognosis, a fraction of thyroid tumors are not cured by standard therapy and progress to aggressive forms for which no effective treatments are currently available. In order to identify novel therapeutic targets for thyroid carcinoma, we focused on the discovery of genes essential for sustaining the oncogenic phenotype of thyroid tumor cells, but not required to the same degree for the viability of normal cells (non-oncogene addiction paradigm). We screened a siRNA oligonucleotide library targeting the human druggable genome in thyroid cancer BCPAP cell line in comparison with immortalized normal human thyrocytes (Nthy-ori 3-1). We identified a panel of hit genes whose silencing interferes with the growth of tumor cells, while sparing that of normal ones. Further analysis of three selected hit genes, namely Cyclin D1, MASTL and COPZ1, showed that they represent common vulnerabilities for thyroid tumor cells, as their inhibition reduced the viability of several thyroid tumor cell lines, regardless the histotype or oncogenic lesion. This work identified non-oncogenes essential for sustaining the phenotype of thyroid tumor cells, but not of normal cells, thus suggesting that they might represent promising targets for new therapeutic strategies

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC

Post-Traumatic Stress Related to Pediatric Illness and Injury

The chapter describes the peculiarities of individual and family responses to the experience of children's medical illness, injury and medical treatment as referred to the construct of traumatic stress. On the basis of the most recent literature, author exoplores the precitive role of a series of factors considered to favor or to inhibit the onset of traumatic stress in peditric illness and injuries; these include: sociodemographic variables preceding the traumatic event; the objective nature of the traumatic event and its subjective evaluation; acute distress and physiological arousal reactions; and finally the parent-child relationship, family functioning and social support

An Examination of the Synergy of Age and PTSD on Narrative Coherence in Child Sexual Abuse Testimony

In a criminal proceeding, a witness is considered as reliable if he/she can recall in narrative form the events, chronologically ordered, with salient contextual (place and time) details, and essential evaluations for the definition of meanings. This study aimed to confirm the effects of age and PTSD on narrative coherence and to investigate the moderating role of age on the association between PTSD and narrative coherence. Narrative coherence was analyzed in 92 allegations of children (M = 10.3; range: 4–17), who were victims of sexual abuse. Thirty-five children presented the symptoms for a diagnosis of PTSD. Each deposition has been codified through the Narrative Coherence Coding Scheme, a coding scheme based on the three independent dimensions (context, chronology, and theme). Correlation analysis indicated the positive associations between age and context, chronology, and theme; and the negative associations between PTSD symptoms and context, chronology, and theme. Predictive effect of PTSD became less and less significant with increasing age. This study could underline the importance of age and PTSD (and their synergy) in legal testimony of children who have been sexually abused