Cannibalism in temporary waters. Simulations and laboratory experiments revealed the role of spatial shape in the mosquito Aedes albopictus

Cannibalism is a commonly observed phenomenon in arthropod species having relevant consequences for population dynamics and individual fitness. It is a context-dependent behaviour and an understanding of the factors affecting cannibalism rate is crucial to highlight its ecological relevance. In mosquitoes, cannibalism between larval stages has been widely documented, and the role of density, food availability and length of contact between individuals also ascertained. However, although mosquitoes can develop in temporary water habitats with very heterogeneous topologies, the role of the site shape where cannibals and victims co-occur has been instead overlooked. In this paper, we investigated this issue by using a simulation approach and laboratory cannibalism experiments between old (third- and fourth-instars) and young (first-instar) larvae of the tiger mosquito Aedes albopictus. Three virtual spaces with different shapes were simulated and the number of larval encounters was estimated in each one to assess whether the spatial shape affected the number of encounters between cannibal and victims. Then, experimental trials in containers with similar shapes to those used in the simulations were performed, and the cannibalism rate was estimated at 24 and 48h. Our results showed that the spatial shape plays a role on cannibalism interactions, affecting the number of encounters between individuals. Indeed, in the experimental trials performed, we observed the highest cannibalism rate in the container with the highest number of encounters predicted by the simulations. Interestingly, we found also that spatial shape can affect cannibalism not only by affecting the number of encounters, but also the number of encounters ªfavorableº for cannibalistic events. Temporary waters are inhabited by several species other than mosquitoes. Our results, showing an influence of the spatial shape on cannibalism in Ae. albopictus larvae, add a new critical factor to those affecting ecological interactions in these habitats

Towards quantum frequency combs: boosting the generation of highly nonclassical light states by cavity-enhanced parametric down-conversion at high repetition rates

We demonstrate the generation of multi-photon quantum states of light by cavity-enhanced parametric down-conversion in the high-repetition-rate pulsed regime. An external enhancement cavity resonant with the spectral comb of modes of a mode-locked pump laser provides a coherent build-up of the pump intensity and greatly enhances the parametric gain without sacrificing its high repetition rate and comb structure. We probe the parametric gain enhancement by the conditional generation and tomographic analysis of two-photon Fock states. Besides its potential impact to efficiently generate highly-nonclassical or entangled multi-photon states in many existing experimental setups, this scheme opens new and exciting perspectives towards the combination of quantum and comb technologies for enhanced measurements and advanced quantum computation protocols.Comment: 5 pages 3 figures; updated with major additions, added references, and changed title. Accepted for publication in Physical Review

Tomographic test of Bell's inequality for a time-delocalized single photon

Time-domain balanced homodyne detection is performed on two well-separated temporal modes sharing a single photon. The reconstructed density matrix of the two-mode system is used to prove and quantify its entangled nature, while the Wigner function is employed for an innovative tomographic test of Bell's inequality based on the theoretical proposal by Banaszek and Wodkiewicz [Phys. Rev. Lett. 82, 2009 (1999)]. Provided some auxiliary assumptions are made, a clear violation of Banaszek-Bell's inequality is found.Comment: 7 pages, 3 figures: revised version with additional material; accepetd for publication in Phys. Rev.

End point prick test: could this new test be used to predict the outcome of oral food challenge in children with cow's milk allergy?

Background: Cow\u2019s milk allergy (CMA) is the most frequent food allergy in childhood; the trend of CMA is often characterized by a progressive improvement to achieve tolerance in the first 4 to 5 years of life. It has been observed that specific IgE (sIgE) towards cow\u2019s milk proteins decrease when the age increases. Although food allergy can be easily diagnosed, it is difficult to predict the outcome of the oral food challenge (OFC), that remains the gold standard in the diagnosis of food allergy, by allergometric tests. Methods: We considered 44 children with CMA diagnosed through OFC who returned to our Allergy and Immunology Pediatric Department between January to December 2010 to evaluate the persistence of allergy or the achievement of tolerance. On the basis of the history, we performed both allergometric skin tests and OFC in children that were still following a milk-free diet, whereas only allergometric skin tests those that had already undergone spontaneous introduction of milk protein at home without presenting symptoms. Objective: The aim of this study was to investigate the relationship between the persistence of CMA or the acquisition of tolerance and the results of the end point prick test (EPT). Results and Discussion: The OFC with cow\u2019s milk was performed on 30 children, 4 children were excluded because of a history of severe reactions to cow\u2019s milk, and 10 because they had spontaneously already taken milk food derivates at home without problems. 16/30 (53%) children showed clinical reactions and the challenge was stopped, 14/30 (47%) did not have any reaction. Comparing the mean wheal diameter of every EPT\u2019s dilution between the group of allergic children and the tolerant ones, we obtained a significant difference (p < 0.05) for the first 4 dilutions. We have also calculated sensitivity (SE), specificity (SP), the positive predictive value (PPV) and the negative predictive value (NPV) for each EPT dilution. Conclusions: EPT is a safe and cheap test, easy to be executed and that could provide good prediction of the outcome of OFC; so it might be used to avoid OFC-induced anaphylaxis in children affected by CMA. It can also help avoiding dietetic restrictions in tolerant children who show sensitization towards cow\u2019s milk proteins

Characterization of natural clays from italian deposits with focus on elemental composition and exchange estimated by edx analysis: potential pharmaceutical and cosmetic uses

Purification processes performed on natural clays to select specific clay minerals are complex and expensive and can lead to over-exploitation of some deposits. The present study aimed to examine physicochemical (mineralogy, morphology, size, surface charge, chemical composition, cation exchange capacity [CEC], and pH) and hydration (swelling, wettability, water sorption, and rheological behavior) properties of three native clays from Italian deposits for potential pharmaceutical and cosmetic uses due to the presence of phyllosilicate minerals. Particular emphasis was placed on energy dispersive X-ray (EDX) microanalysis coupled with the ‘cesium method’ to assay clay elemental composition and CEC. One bentonite of volcanic origin (BNT) and two kaolins, one of hydrothermal origin (K-H) and another of lacustrine-fluvial origin (K-L), were evaluated in comparison with a commercial, purified bentonite. The CEC assay revealed the complete substitution of exchangeable cations (Na+ and Ca2+) by Cs+ in BNT samples and CEC values consistent with those of typical smectites (100.64 7.33 meq/100 g). For kaolins, partial substitution of Na+ cations occurred only in the K-L samples because of the interstratified mineral component which has small CEC values (11.13 5.46 meq/100 g for the K-H sample and 14.75 6.58 meq/100 g for the K-L sample). The degree of isomorphous substitution of Al3+ by Mg2+ affected the hydration properties of BNT in terms of swelling, water sorption, and rheology, whereas both of the poorly expandable kaolins exhibited significant water-adsorption properties. The EDX microanalysis has proved to be of considerable interest in terms of providing more information about clay properties in comparison with other commonly used methods and to identify the role played by both chemical and mineralogical composition of natural clays for their appropriate use in pharmaceutical and cosmetic fields

COVID-19 respiratory support outside the ICU's doors. An observational study for a new operative strategy

During the first wave of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) pandemic, we faced a massive clinical and organizational challenge having to manage critically ill patients outside the Intensive Care Unit (ICU). This was due to the significant imbalance between ICU bed availability and the number of patients presenting Acute Hypoxemic Respiratory Failure caused by SARS-CoV-2-related interstitial pneumonia. We therefore needed to perform Non-Invasive Ventilation (NIV) in non-intensive wards to assist these patients and relieve pressure on the ICUs and subsequently implemented a new organizational and clinical model. This study was aimed at evaluating its effectiveness and feasibility

Physiological pregnancy in a tiger affected by endometritis and benign mesenchymal neoplasm.

In large felids, uncomplicated endometritis and benign mesenchymal uterine tumours usually represent post-mortem findings. These pathologies generally remain clinically asymptomatic, and their impact on reproductive outcome and maternal care is unknown. A 13-year-old female tiger (Panthera tigris) was evaluated by a team of veterinarians from the University of Padova for abnormal behaviour after parturition. The animal spontaneously gave birth to a healthy male cub of 1.460 kg, but after three hours of normal parental care, she showed careless about the cub, occasional abdominal contractions, excessive self-licking and restlessness. After 10 hours of continuous observation, the tiger was anaesthetised for a complete clinical evaluation. The physical examination was unremarkable, but a vaginal bloody/mucous discharge with no obstruction of the birth canal was noted. Abdominal ultrasound revealed an enlarged left uterine horn with heterogeneous echogenicity. Blood analysis showed moderate neutrophilia and leucocytosis. Differential diagnoses included placental retention, uterine inflammation/infection, neoplasia. The tiger was transferred to the Veterinary Teaching Hospital where the explorative laparotomy and the ovario-hysterectomy were performed. The uterine horns appeared asymmetric and two nodular lesions of 1.5-cm-diameter were observed on the left horn. Histological assessment indicated the presence of a multifocal, subacute, moderate neutrophilic endometritis in both horns associated with diffuse, severe oedema. The nodules were consistent with a mesenchymal benign neoplasia. No relevant complication was observed in the following postoperative period and the cub was successfully hand raised. To the best of our knowledge, no report describes the birth of a healthy cub from a tiger affected by endometritis and neoplasia. Considering the normal maternal care observed in the previous twin-pregnancies in this animal, we cannot exclude that the uterine affection caused her abnormal behaviour in this case. Therefore, careful observation of the mother in the post-partum period is always strongly recommended