CaloCube: a novel calorimeter for high-energy cosmic rays in space

In order to extend the direct observation of high-energy cosmic rays up to the PeV region, highly performing calorimeters with large geometrical acceptance and high energy resolution are required. Within the constraint of the total mass of the apparatus, crucial for a space mission, the calorimeters must be optimized with respect to their geometrical acceptance, granularity and absorption depth. CaloCube is a homogeneous calorimeter with cubic geometry, to maximise the acceptance being sensitive to particles from every direction in space; granularity is obtained by relying on small cubic scintillating crystals as active elements. Different scintillating materials have been studied. The crystal sizes and spacing among them have been optimized with respect to the energy resolution. A prototype, based on CsI(Tl) cubic crystals, has been constructed and tested with particle beams. Some results of tests with different beams at CERN are presented.Comment: Seven pages, seven pictures. Proceedings of INSTR17 Novosibirs

Cat epididymal semen cryopreserved with and without vitamin E: effect on sperm parameters and lipid peroxidation

The aims of this study were to investigate: 1) if the addition of \u3b1-tocopherol (vitamin E) in three concentrations (0.3, 0.6 and 0.9 mM) is able to preserve spermatozoa integrity after thawing and 2) the effect of \u3b1-tocopherol supplementation on lipid peroxidation. Fifty four domestic cats were used in this study constituting 18 pools (3 cats per pool). Each pool was submitted at four experimental groups: group 0 (control) \u2013 epididymal sperm were frozen with a commercial Botucrio\uae extender; group 0.3, group 0.6 and group 0.9 \u2013 the extender was supplemented with 0.3, 0.6 and 0.9 mM of \u3b1-tocopherol, respectively. Each semen sample was evaluated for motility, progressive forward motility, morphology, sperm viability (plasma membrane integrity-PMI), hypo-osmotic swelling test (HOST), before and after thawing. The evaluation of lipid peroxidation reaction by Thiobarbituric Acid Reactive Substances (TBARS) test was performed on thawed semen only. Results demonstrated that there was no significant difference between control and the three \u3b1-tocopherol groups with regards to motility and progressive motility after thawing (P > 0.05). As expected, in fresh samples viability was significantly higher than in all the cryopreserved groups in which there was no positive influence of any of the \u3b1-tocopherol concentration used. Lipid peroxidation was higher in the supplemented groups 0.6 and 0.9 mM of \u3b1-tocopherol than in control and in 0.3 mM group. In conclusion, the addition of \u3b1-tocopherol to the commercial extender had no positive influence on reduction of lipid peroxidation. This topic deserves further investigations to better understand the effect of cryopreservation procedures on epididymal spermatozoa and to establish adequate strategies to counteract sperm cryodamages

Multi-wavelength observations of blazar AO 0235+164 in the 2008-2009 flaring state

The blazar AO 0235+164 (z = 0.94) has been one of the most active objects observed by Fermi Large Area Telescope (LAT) since its launch in Summer 2008. In addition to the continuous coverage by Fermi, contemporaneous observations were carried out from the radio to γ-ray bands between 2008 September and 2009 February. In this paper, we summarize the rich multi-wavelength data collected during the campaign (including F-GAMMA, GASP-WEBT, Kanata, OVRO, RXTE, SMARTS, Swift, and other instruments), examine the cross-correlation between the light curves measured in the different energy bands, and interpret the resulting spectral energy distributions in the context of well-known blazar emission models. We find that the γ-ray activity is well correlated with a series of near-IR/optical flares, accompanied by an increase in the optical polarization degree. On the other hand, the X-ray light curve shows a distinct 20 day high state of unusually soft spectrum, which does not match the extrapolation of the optical/UV synchrotron spectrum. We tentatively interpret this feature as the bulk Compton emission by cold electrons contained in the jet, which requires an accretion disk corona with an effective covering factor of 19% at a distance of 100 R g. We model the broadband spectra with a leptonic model with external radiation dominated by the infrared emission from the dusty torus. © 2012. The American Astronomical Society. All rights reserved

Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society

Epididymal spermatozoa: a hidden treasure with great potential

An azoospermic ejaculate or a \u201cdry ejaculate\u201d, as it is called in case of aspermia, might not be the end of the hopes of procreation. When a donor male accidentally dies or undergoes orchiectomy for medical reasons can still generate offspring. In both cases, the precious germplasm can be hidden in the epididymides as a treasure with great potential. Epididymal spermatozoa can be retrieved from ex vivo or in vivo testicles, can be cryopreserved and used in assisted reproductive technologies (ARTs). This review intends to shed light on these topics providing a critical analysis on recent results obtained in carnivores. From ex vivo testicles, spermatozoa can be collected by mincing the epididymal cauda in a Petri dish containing medium, or by flushing or squeezing epididymides and deferential ducts. Different techniques have been tested in humans to retrieve epididymal spermatozoa from in vivo testicles. We previously investigated the feasibility in dogs of one of these methods: the percutaneous epididymal sperm aspiration (PESA). The quality of gametes was similar to that of those collected from ex vivo testicles, although a wide variation in concentration amongst animals was observed1. During epididymal transit, functional and structural modifications leading to full maturation enable male gametes to reach, recognize and fertilize the oocytes. An extensive analysis has been conducted in cats and characteristics of the spermatozoa collected from six different epididymal regions have been described in detail2. We demonstrated that DNA integrity of feline epididymal spermatozoa seems to be independent from all the measured variables of sperm head morphology and morphometry3. In dogs, we showed that an acrosomal reshaping occurs during maturation from the proximal to the distal epididymal tract and that the migration of the cytoplasmic droplet occurs in the epididymal corpus. Thus, the highest sperm motility, acrosomal integrity and normal morphology is found in the cauda4. The fertilizing ability of fresh and frozen epididymal spermatozoa has been demonstrated in several mammalian species including carnivores. In vitro embryo production in cats have been successfully obtained with epididymal spermatozoa. In dogs, intravaginal and intrauterine artificial insemination with fresh and frozen epididymal spermatozoa resulted in pregnancies and in viable puppies. We found that DNA fragmentation is not affected by the freezing procedure further demonstrating that epididymal spermatozoa can be successfully cryopreserved5. The hidden treasure represented by epididymal spermatozoa deserves special attention and serious consideration for its potential use in the current reproductive technologies. [1] Varesi S, Vernocchi V, Faustini M, et al. Quality of canine spermatozoa retrieved by Percutaneous Epididymal Sperm Aspiration. J Small Anim Pract 2013;54:87-91. [2] Axn\ue9r E, Linde-Forsberg C, Einarsson S: Morphology and motility of spermatozoa from different regions of the epididymal duct in the domestic cat. Theriogenology 1999;52:767-778. [3] Vernocchi V, Morselli MG, Lange Consiglio A et al. DNA fragmentation and sperm head morphometry in cat epididymal spermatozoa. Theriogenology 2014;82:982-987. [4] Varesi S, Vernocchi V, Faustini M, et al. Morphological and acrosomal changes of canine spermatozoa during epididymal transit. Acta Vet Scand 2013;55:17. [5] Varesi S, Vernocchi V, Morselli MG, et al. DNA integrity of fresh and frozen canine epididymal spermatozoa. Reprod Biol 2014;14:257-261

ARTs as a tool for overcoming fertility problems in dogs and cats

In human medicine, assisted reproductive techniques (ARTs) are categorize into three levels based on complexity and invasiveness. The physician should select the appropriate procedure, giving priority to the easiest and less invasive technique. In dogs and cats, ARTs aimed at improving reproductive performances and treating male and female infertility, should respect the same guidelines. Thus, in the case of infertility, a careful clinical examination, a diagnosis of the etiology of infertility, and conventional treatments (first-level ARTs) should be attempted before planning more complex procedures (second- and third-level ARTs). First-level ARTs include artificial insemination with fresh or cryopreserved semen, and pharmacological treatments, e.g induction of estrus or ovulation. These ARTs may be applied in cases of impotentia coeundi, primary or secondary anestrus, or ovulation failure. Second-level and third-level ARTs include in vitro embryo production (i.e. in vitro fertilization-embryo transfer \u2013 IVF-ET; intracytoplasmic sperm injection - ICSI), with the use of epididymal or testicular spermatozoa, other than ejaculated spermatozoa, and fresh or cryopreserved oocytes. This review is focused on second- and third-level ARTs that have been developed in dogs and cats

Canine epididymal spermatozoa : a hidden treasure with great potential

The hidden treasure represented by epididymal spermatozoa has great potential in the current reproductive technologies in dogs. In case of azoospermia or when a donor male accidentally dies or undergoes orchiectomy, the retrieval of epididymal spermatozoa opens new possibilities to generate progeny. Spermatozoa can be collected by different techniques from ex vivo or in vivo testicles and can be cryopreserved for a future use. Freeze tolerance of canine epididymal spermatozoa seems lower than that of ejaculated spermatozoa; however, puppies were born after artificial insemination with frozen epididymal semen, other than with fresh and chilled. Even though several aspects need to be further investigated, advances have been recently made in the use of epididymal spermatozoa in assisted reproduction in dogs

Cat vitrified oocytes culture in 3D liquid marble microbioreactors

Liquid marbles, also known as pearl drops, are three-dimensional (3D) microbioreactors in which living cells can survive, proliferate and react to stimuli. The pillar on which this technology is established is the use of non-adhesive, hydrophobic molecules to create a casing that maintains the cells suspended in a small volume of inner liquid and has the right porosity to allow free exchange of gases (1). Microorganisms, tumor spheroids, red blood cells and embryonic stem cells have been cultured in liquid marbles, and their survival and growth were successfully obtained (1\u20133). This microbioreactor, that better resembles the in vivo conditions compared to two-dimensional (2D) cultures, might also be beneficial for female gametes, and especially for the low-competence cryopreserved oocytes. However, only one study with fresh sheep gametes (4) provided some information on the usefulness of this environment for in vitro maturation (IVM). In this study, the efficiency of liquid marbles as 3D microbioreactors for the IVM of vitrified domestic cat oocytes was assessed and compared with that of traditional microdrops of medium (2D). Material and methods: Fresh ovaries (n = 30) from domestic queens were obtained after surgery and cumulus oocytes complexes (COCs) were collected. Sixty-five COCs were vitrified by Cryotop method (5) and, after warming, morphologically intact (6) vitrified oocytes (VOs, n = 59) were cultured in 3D liquid marbles (n = 30) or in 2D microdrops of medium (n = 29). To create the 3D microbioreactor, a chemically inert hydrophobic powder (polytetrafluoroethylene, PTFE; Sigma-Aldrich, St. Louis, MO, USA) was used following a published protocol (4). Oocytes were matured for 24 h in a controlled atmosphere (38.5\ub0C and 5% CO2 in air) in TCM199 supplemented with 10% FBS, 10 ng/mL EGF, 0.6 mM cysteine (Sigma-Aldrich) and 0.5 IU/mL FSH + 0.5 IU/mL LH (Pluset, Calier, Spain). Chromatin configurations were determined by bisbenzimide (Hoechst 33342; Sigma-Aldrich) staining, and data were analyzed by Chi-square test, with the level of significance set at p < 0.05. Results: Vitrified oocytes resumed meiosis at similar proportions in 3D and 2D culture conditions (3D: 50% vs. 2D: 55.2%; p = 0.69), and the same trend was observed for full maturation (3D: 13.3% vs. 2D: 13.8%; p = 0.96). Conclusions: Liquid marble technology, even if promising for different types of somatic cells, in these experimental conditions had the same effect as traditional 2D culture on cat immature vitrified oocytes IVM. To fully restore and boost the developmental competence of feline cryopreserved oocytes other systems remain to be investigated. References: 1) Arbatan et al., Adv Healthc Mater 2012;1:467\u20139. 2) Arbatan et al., Adv Healthc Mater 2012;1:80\u20133. 3) Sarvi et al., Adv Healthc Mater 2015;4:77\u201386. 4) Ledda et al., J Assist Reprod Genet 2016;33:513\u20138. 5) Kuwayama, Theriogenology 2007;67:73\u201380. 6) Apparicio et al., Reprod Dom Anim 2013;48:240\u20134

Fertility preservation in felids

With an increasing number of endangered feline species, their genome resource banking is of paramount importance. The storage of germplasm (gametes, embryos, gonadal tissues) is crucial to maintain biodiversity and to improve the fertility potential in wild species and domestic valuable breeds. Gamete cryobanking \u2013 Semen cryopreservation is the safer choice for male fertility preservation. Ejaculated or epididymal spermatozoa can be frozen with acceptable results (Luvoni 2006, Theriogenology 66:101\u201311). The female counterpart is more complex, as oocytes are larger and more sensitive cells, which often lose their developmental competence after cryostorage. Protocols still need to be optimized: encouraging results have been obtained in the domestic cat (Luvoni 2012, Reprod Dom Anim 47 Suppl. 6:266\u20138), but embryo development from cryopreserved oocytes has never been reported in wild felids. Gonadal tissue cryobanking \u2013 Testicular and ovarian tissues are abundant sources of gametes. Both freezing and vitrification of the male and female gonads have been achieved and ovarian cryobanking is already performed for some wild felids. Other techniques for fertility preservation \u2013 Freeze- drying is an interesting alternative to conventional freezing, but even if already applied to domestic cat and jaguar semen, it is still highly experimental. Oocyte nuclear preservation (germinal vesicle) by air- drying or microwave- assisted drying has been also attempted in cats, but it requires further studies. Conclusion \u2013 We are aware that there is still much to do, but also that with the improvement of fertility preservation procedures, the dream of safeguarding threatened felids, as in a modern Noah \u2019 s Ark, might come true

The nuclear and developmental competence of cumulus-oocyte complexes is enhanced by three-dimensional coculture with conspecific denuded oocytes during in vitro maturation in the domestic cat model

The objective of the study was to assess the efficacy of coculture with conspecific cumulus-denuded oocytes (CDOs) during in vitro maturation in a three-dimensional system of barium alginate microcapsules on the in vitro embryo development of domestic cat cumulus-oocyte complexes (COCs). In Experiment I, COCs were cocultured with conspecific CDOs or cultured separately in a 3D system for 24\ua0hr of in vitro maturation, before assessing the meiotic progression. In Experiment II, the in vitro fertilization of COCs and CDOs was carried out with chilled epididymal spermatozoa and the presumptive zygotes were cultured in vitro separately for 7\ua0days in 3D microcapsules before assesment of embryonic development. The results showed that the viability was maintained and that meiosis was resumed in the 3D culture system. The presence of CDOs during in vitro maturation improved the meiotic competence of the COCs, since the proportions of telophase I/metaphase II were higher than that in the groups cultured separately. The enrichment of the maturation system by companion oocytes also enhanced the ability of COCs to develop into embryos, and increased the percentages of morula and blastoycst stages. The COCs cocultured with CDOs developed at higher rates than the COCs cultured separately and the CDOs themselves. The beneficial effects of coculture with conspecific CDOs were presumably due to the paracrine action of some secreted factors that enhanced many molecular patterns related to the complex of cumulus oophorous cells. Further investigations to understand how the 3D microenvironment can influence the features of oocytes and embryos are required