A glass workshop in ‘Aqir, Israel and a new type of compositional contamination

Materials associated with a secondary workshop of early Byzantine date (4th-5th centuries) were unearthed in excavations by the Israel Antiquities Authority in ‘Aqir, central Israel. Fragments of furnace structure, production debris and glass vessels have been analysed by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDS) and thin-section petrography. The results suggest that the workshop melted raw glass chunks of similar composition to the primary glass made at Apollonia, Israel, to produce secondary glass products. Some glass vessels associated with the furnace are of different composition, and some of these may represent material brought in as cullet for recycling. The furnace was built with ceramic bricks comprising alluvial-type clay with inclusions of quartz sand, probably added as temper. It was fired by potash-rich fuel to approximately 1100°C. Lime mortar was used either to cement the gaps between mudbricks or to line the furnace as a parting layer, and it has introduced a previously unrecognised type of contamination in glass of the period, mainly of Fe2O3 and CaO. The contamination may be identified in glass vessel assemblages elsewhere but is not ubiquitous. As its origin relates to the furnace structure, its occurrence may depend upon chronology or geography and further work is needed to resolve this issue

Kairouan and the medieval ceramic industry in Tunisia: New data from compositional analysis of glazed and unglazed wares from the sites of Bulla Regia and Chimtou

The technology and provenance of 50 medieval glazed and 15 unglazed ceramics (9th-12th c.) from Bulla Regia and Chimtou (ancient Simitthus), in the Medjerda Valley, Tunisia, have been characterised using thin section petrography, LA-ICP-MS and SEM-EDS. All ceramics appear to have been made in Tunisia, except for two samples which are imports from Palermo (Sicily). The bodies of most of the glazed and unglazed wares have very similar compositions and were likely manufactured in central Tunisia (Kairouan region) and then traded to the two sites. Manufacture local to the two sites seems to have been limited to handmade wares and perhaps lamps. The production of both glazed and unglazed wheelmade wares using central Tunisian clays suggests a model in which Kairouan was a major production centre and distributor of ceramics. The data suggest that different Kairouan workshops may have specialised in different types of wares. The identification of smaller chemical and petrographic groups may indicate the existence of other unlocated regional production centres which were secondary to Kairouan as a source of ceramics for the northwest Medjerda Valley. All glazes are lead based, containing varying amounts of alkalis. The majority of the glazes are translucent, with just three that are tin-opacified. It is suggested that the source of lead used for glazing was scrap lead metal with a complex life history, originally obtained from the reduction of litharge produced as a side product of silver extraction and showing signs of subsequent recycling

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties

Separation of track- and shower-like energy deposits in ProtoDUNE-SP using a convolutional neural network

Liquid argon time projection chamber detector technology provides high spatial and calorimetric resolutions on the charged particles traversing liquid argon. As a result, the technology has been used in a number of recent neutrino experiments, and is the technology of choice for the Deep Underground Neutrino Experiment (DUNE). In order to perform high precision measurements of neutrinos in the detector, final state particles need to be effectively identified, and their energy accurately reconstructed. This article proposes an algorithm based on a convolutional neural network to perform the classification of energy deposits and reconstructed particles as track-like or arising from electromagnetic cascades. Results from testing the algorithm on experimental data from ProtoDUNE-SP, a prototype of the DUNE far detector, are presented. The network identifies track- and shower-like particles, as well as Michel electrons, with high efficiency. The performance of the algorithm is consistent between experimental data and simulation

Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment

The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE's sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-years (kt-MW-yr). The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 3σ (5σ) level, with a 66 (100) kt-MW-yr far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters. We also show that DUNE has the potential to make a robust measurement of CPV at a 3σ level with a 100 kt-MW-yr exposure for the maximally CP-violating values \delta_{\rm CP}} = \pm\pi/2. Additionally, the dependence of DUNE's sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest

Acute action of rotenone on nigral dopaminergic neurons--involvement of reactive oxygen species and disruption of Ca2+ homeostasis

Abstract Rotenone is a toxin used to generate animal models of Parkinson’s disease; however, the mechanisms of toxicity in substantia nigra pars compacta (SNc) neurons have not been well characterized. We have investigated rotenone (0.05–1 lm) effects on SNc neurons in acute rat midbrain slices, using whole-cell patch-clamp recording combined with microfluorometry. Rotenone evoked a tolbutamide-sensitive outward current (94 ± 15 pA) associated with increases in intracellular [Ca2+] ([Ca2+]i) (73.8 ± 7.7 nm) and intracellular [Na+] (3.1 ± 0.6 mm) (all with 1 lm). The outward current was not affected by a high ATP level (10 mm) in the patch pipette but was decreased by Trolox. The [Ca2+]i rise was abolished by removing extracellular Ca2+, and attenuated by Trolox and a transient receptor potential M2 (TRPM2) channel blocker, N-(p-amylcinnamoyl) anthranilic acid. Other effects included mitochondrial depolarization (rhodamine-123) and increased mitochondrial reactive oxygen species (ROS) production (MitoSox), which was also abolished by Trolox. A low concentration of rotenone (5 nm) that, by itself, did not evoke a [Ca2+]i rise resulted in a large (46.6 ± 25.3 nm) Ca2+ response when baseline [Ca2+]i was increased by a ‘priming’ protocol that activated voltage-gated Ca2+ channels. There was also a positive correlation between ‘naturally’ occurring variations in baseline [Ca2+]i and the rotenone-induced [Ca2+]i rise. This correlation was not seen in non-dopaminergic neurons of the substantia nigra pars reticulata (SNr). Our results show that mitochondrial ROS production is a key element in the effect of rotenone on ATP-gated K+ channels and TRPM2-like channels in SNc neurons, and demonstrate, in these neurons (but not in the SNr), a large potentiation of rotenone-induced [Ca2+]i rise by a small increase in baseline [Ca2+]i

Properties of dopaminergic neurons in organotypic mesencephalic-striatal co-cultures--evidence for a facilitatory effect of dopamine on the glutamatergic input mediated by α-1 adrenergic receptors.

Organotypic cultures (OCs) have been widely used to investigate the midbrain dopaminergic system, but only a few studies focused on the functional properties of dopaminergic neurons and their synaptic inputs from dopaminergic and non-dopaminergic neuronsalso contained in such cultures. In addition, it is not clear whether the culturing process affects the intrinsic neuronal properties and the expression of specific receptors and transporters. We performed patch-clamp recordings from dopaminergic neurons in mesencephalic–striatal co-cultures obtained from transgenic mice expressing green fluorescent protein (GFP) under the tyrosine hydroxylase promoter. Some (10 ⁄ 44) GFP+ neurons displayed a bursting activity that renders the firing of these cells similar to that of the dopaminergic neurons in vivo. The culturing process reduced the hyperpolarization-activated current (Ih) and the expression of D2 receptors. Downregulation of D2 receptor mRNA and protein was confirmed with reverse transcriptase polymerase chain reaction and Western blotting. Immunocytochemistry revealed that many synaptic terminals, most likely originating from dopaminergic neurons, co-expressed the dopamine (DA) transporter and the vesicular glutamate transporter-2, suggesting a co-release of DA and glutamate. Interestingly, exogenous DA decreased glutamate release in young cultures [days in vitro (DIV) < 20] by acting on pre-synaptic D2 receptors, while in older cultures (DIV > 26) DA increased glutamate release by acting on a-1 adrenoreceptors. The facilitatory effect of DA on glutamatergic transmission to midbrain dopaminergic neurons may be important in conditions when the expression of D2 receptors is compromised, such as long-term treatment with antipsychotic drugs. Our data show that midbrain OCs at DIV > 26 may provide a suitable model of such condition

Properties of dopaminergic neurons in organotypic mesencephalic-striatal co-cultures--evidence for a facilitatory effect of dopamine on the glutamatergic input mediated by \u3b1-1 adrenergic receptors.

Organotypic cultures (OCs) have been widely used to investigate the midbrain dopaminergic system, but only a few studies focused on the functional properties of dopaminergic neurons and their synaptic inputs from dopaminergic and non-dopaminergic neurons also contained in such cultures. In addition, it is not clear whether the culturing process affects the intrinsic neuronal properties and the expression of specific receptors and transporters. We performed patch-clamp recordings from dopaminergic neurons in mesencephalic-striatal co-cultures obtained from transgenic mice expressing green fluorescent protein (GFP) under the tyrosine hydroxylase promoter. Some (10/44) GFP+ neurons displayed a bursting activity that renders the firing of these cells similar to that of the dopaminergic neurons in vivo. The culturing process reduced the hyperpolarization-activated current (I(h) ) and the expression of D\u2082 receptors. Downregulation of D\u2082 receptor mRNA and protein was confirmed with reverse transcriptase polymerase chain reaction and Western blotting. Immunocytochemistry revealed that many synaptic terminals, most likely originating from dopaminergic neurons, co-expressed the dopamine (DA) transporter and the vesicular glutamate transporter-2, suggesting a co-release of DA and glutamate. Interestingly, exogenous DA decreased glutamate release in young cultures [days in vitro (DIV)<20] by acting on pre-synaptic D\u2082 receptors, while in older cultures (DIV>26) DA increased glutamate release by acting on \u3b1-1 adrenoreceptors. The facilitatory effect of DA on glutamatergic transmission to midbrain dopaminergic neurons may be important in conditions when the expression of D\u2082 receptors is compromised, such as long-term treatment with antipsychotic drugs. Our data show that midbrain OCs at DIV>26 may provide a suitable model of such conditions