On Correction Factor In Scaling Law For Low Pressure Dc Gas Breakdown

The low pressure gas breakdown described by Paschen's law in Townsend theory, i.e. the breakdown voltage as a function of gas pressure p and the electrode distance d, provides an accurate description of breakdown in DC discharges when the ratio between inter-electrode gap distance d and electrode radii R tends to zero. On increasing of the ratio d/R, the Paschen's curves are shifted to the region of higher breakdown voltage and higher pd values. A modified Paschen's law recently proposed is well satisfied in our measurements. However, the value of constant b changes not only due to gas type but also according to electrode gap distance; furthermore, gas breakdown voltages are considerably modified by plasma-wall interactions due to glass tube proximity in the discharge.5111Townsend, J.S., (1915) Electricity in Gases, , Oxford: ClarendonKolobov, V.I., Fiala, A., (1994) Phys. Rev., 50, pp. 3018-3032Lisovskiy, V.A., Yakovin, S.D., Yegorenkov, V.D., (2000) J. Phys. D: Appl. Phys., 33 (21), pp. 2722-2730. , 0022-3727 310Raizer, Y.P., (1991) Gas Discharge Physics, , 10.1007/978-3-642-61247-3 (Berlin: Springer

Remarks on the Permian-Triassic transition in Central and Eastern Lombardy (Southern Alps, Italy)

The main lithological and petrographical characteristics of the Permian-Lower Triassic Orobic and Brescian successions in central and eastern Lombardy are briefl y recorded, especially with regard to the units cropping out below and above the P-T boundary. The lower formation is represented by the Verrucano Lombardo, which consists of continental, fluvial red clastics, barren of fossils, generally Late Permian (Lopingian) in age, whereas the overlying Servino Formation, which is represented by well-bedded clastic and carbonate polychrome sediments, generally rich in fossils, pertains to the Early Triassic (Induan-Olenekian). The sequences of the two above-mentioned areas differ at least in part, as proof of their regional division, probably because of an inherited paleotopography and syntectonic activity. Taking into account the units bracketing the P-T boundary, which represents the real topic of this work, the Verrucano Lombardo of the Orobic Alps is paraconformably covered by the conglomerates and sandstones of the Prato Solaro Member in the lower part of the Servino Formation, cropping out extensively, although discontinuously, from the eastern side of Lake Como to the upper Scalve Valley in the Camonica region. The shape of some quartz rock fragments, derived from the Variscan crystalline basement and its Upper Carboniferous siliciclastic cover, has been interpreted as due to relatively coeval aeolian activity, and testifi es to an arid climatic “event” probably late Dienerian-early Smithian in age. In contrast, in the Brescia province, the onset of the Servino is made up of wave and current rippled, fi ne clastics, 1-2 m thick, and a typical horizon of oolitic dolostones (“Praso Limestone” Auct.), continuous from the lower Camonica Valley to the western Trentino. This unit could laterally correlate towards east, in the eastern South-Alpine segment, with the famous oolitic Tesero Member at the base of the Werfen Formation of the Dolomitic and Carnic Alps. In the Brescian Prealps, the above oolitic deposits crop out below some Claraia beds yielding forms common to those present in the Siusi Member of the Dolomites, generally attributed to late Griesbachian-early Dienerian times. Their age could be ascribed to a slightly older Griesbachian, i.e. to early Induan. Therefore, the P-T boundary in central and eastern Lombardy seems substantially located between the fi nal part of the Permian and the very base of the respective Triassic successions, temporally and spatially ranging in different ways and generally affected by non-depositional and perhaps tectonic processes. In our opinion, however, the duration of the gap, based on correlations with the well-documented stratigraphical studies recently carried out in the nearby Dolomitic area and other European regions, should be considered as slightly longer than previously recognized: the maximum gap could be estimated at about 3-4 Ma. As a consequence, we thus point out that the Servino Formation of the Brescian Alps rests, itself, paraconformably on the Verrucano Lombardo red beds, even if the P-T gap was probably less for correlation with the well-known Dolomites sections. At the end of the paper, for a more comprehensible understanding of the late- to post-Variscan geological scenario, is a tentative synthesis of the regional evolution.Se resumen las principales características litológicas y petrológicas de las sucesiones Oróbica y Bresciana del Pérmico y Triásico Inferior del este de Lombardía, especialmente las referidas a aquellas unidades que afl oran por encima y por debajo del límite P-T. La formación inferior está representada por el “Verrucano Lombardo”, que está constituido de sedimentos continentales clásticos de color rojo, de origen fluvial y sin fósiles y que muestran generalmente una edad Pérmico Superior (Lopingiense), mientras que la unidad inmediatamente superior, Formación Servino, representada por sedimentos bien estratifi cados, clásticos y carbonáticos, con abundantes fósiles y diferentes colores, es de edad Triásico Inferior (Induense-Olenekian). Las sucesiones de las dos áreas arriba mencionadas difieren entre sí, debido, entre otros motivos, a aquellos ligados a las características paleogeográfi cas y tectónicas propias de las zonas en las que afloran. El Verrucano Lombardo, en los afloramientos de los Alpes Oróbicos, que aflora extensivamente aunque de forma discontinua desde la parte este del lago Como hasta la parte alta del valle Scalve, en la región Carmónica, se sitúa, mediante una paraconformidad, bajo los conglomerados y areniscas del Miembro Prato Solaro, pertenecientes a la parte inferior de la Formación Servino. La forma de algunos fragmentos de roca, derivados del basamento cristalino varisco, así como los sedimentos siliciclásticos del Carbonífero Superior que los cubren, han sido relacionadas con una actividad de tipo eólica, testificando un evento climático de tipo árido, probablemente de edad Dieneriense superior-Smithiense inferior. En contraste, en la provincia de Brescia, la Formación Servino está constituida por sedimentos clásticos con ripples de oscilación y corriente, de tamaño de grano fino, constituyendo un espesor de 1-2 m y un nivel típico de dolomías oolíticas (“Praso Limestone” Auct.), que aparece desde la parte inferior del valle de Camonica hasta el oeste Trentino. Hacia el oeste, en el segmento este de los Alpes Meridionales, esta unidad podría correlacionarse lateralmente con el Miembro Tesero, de carácter oolítico, de la base de la Formación Werfen de los Alpes Dolomíticos y Cárnicos. En los Prealpes Brescianos, los depósitos oolíticos anteriormente mencionados afloran por debajo de algunas capas con Claraia, mostrando formas parecidas a las existentes del actual Miembro Siusi de los Dolomitas, generalmente atribuidos a una edad Griesbachiense-Dineriense inferior. Su edad podría ser ligeramente anterior a Griesbachiense, i.e. Induense inferior. Así, el límite P-T en el centro y este de Lombardía, estaría básicamente estar localizado entre la parte final de los sedimentos considerados pérmicos y aquellos de la parte más baja de los considerados Triásico Inferior, aunque con ciertas variaciones temporales y espaciales, variando en función de los procesos no deposicionales y, posiblemente, tectónicos. En nuestra opinión y, basándonos en correlaciones bien documentadas estudios estratigráficos llevados a cabo en los Dolomitas y en otras regiones europeas, prolongación en el tiempo de esta etapa en la que falta registro sedimentario podría ser considerada como ligeramente más larga de lo inicialmente reconocido: esta etapa podría ser considerada en torno a 3-4 Ma. Como consecuencia, consideramos que la Formación Servino de los Alpes Brescianos, como tal, paraconformable sobre las capas rojas del Verrucano Lombardo incluso aunque el vacío sedimentario de la transición P-T en esta zona fuese menor que el de la zona correlacionable y bien conocida de las secciones de los Dolomitas

Reply to discussion on the article “Remarks on the Permian- Triassic transition in Central and Eastern Lombardy (Southern Alps, Italy)” by G. Cassinis, M. Durand and A. Ronchi

Sin resumenSin resume

Self-DNA Early Exposure in Cultivated and Weedy Setaria Triggers ROS Degradation Signaling Pathways and Root Growth Inhibition

The accumulation of fragmented extracellular DNA reduces conspecific seed germination and plantlet growth in a concentration-dependent manner. This self-DNA inhibition was repeatedly reported, but the underlying mechanisms are not fully clarified. We investigated the species-specificity of self-DNA inhibition in cultivated vs. weed congeneric species (respectively, Setaria italica and S. pumila) and carried out a targeted real-time qPCR analysis under the hypothesis that self-DNA elicits molecular pathways that are responsive to abiotic stressors. The results of a cross-factorial experiment on root elongation of seedlings exposed to self-DNA, congeneric DNA, and heterospecific DNA from Brassica napus and Salmon salar confirmed a significantly higher inhibition by self-DNA as compared to non-self-treatments, with the latter showing a magnitude of the effect consistent with the phylogenetic distance between the DNA source and the target species. Targeted gene expression analysis highlighted an early activation of genes involved in ROS degradation and management (FSD2, ALDH22A1, CSD3, MPK17), as well as deactivation of scaffolding molecules acting as negative regulators of stress signaling pathways (WD40-155). While being the first exploration of early response to self-DNA inhibition at molecular level on C4 model plants, our study highlights the need for further investigation of the relationships between DNA exposure and stress signaling pathways by discussing potential applications for species-specific weed control in agriculture

Adopting a cross-scale approach for the deployment of a green infrastructure

The implementation of a Green Infrastructure (GI) involves several actors and governance scales that need adequate knowledge support. The multifunctionality of GI entails the implementation of a cross-scale approach, which combines assessments conducted at different levels and active stakeholder engagement. This paper provides a methodology to implement a cross-scale approach to support the deployment of a Regional GI. The methodology was tested in Lombardy Region (north-west of Italy), considering three relevant territorial scales and relative strategic and planning policies. The continental level representing the overall policy-context; the regional level, with its key role for guaranteeing landscape coherence and connectivity and the local level where planning actions are effectively designed and implemented. The EU Biodiversity Strategy for 2030 and the EU GI strategy were used as references for the continental level; at the regional level, a proposal of Regional GI was evaluated focusing on two Provinces (Varese and Lecco), three regional parks (Ticino, Adda Nord and Campo dei Fiori). At the local scale, the new development plan of the Municipality of Cassano d'Adda (Milan metropolitan area) was evaluated considering different possible scenarios. The regional GI was evaluated with respect to the capacity to provide Cultural Ecosystem Services (CES). CES were mapped using the ESTIMAP-recreation model. The model was adapted to the regional and local level with the active engagement of local stakeholders. Additionally, census data were analysed to obtain an overview of the equitable distribution of the CES amongst inhabitants. Results show that, in 78% of the census blocks of the study area, inhabitants have a high-value recreation resource within 4 km (31% within 4 km and 47% within 300 m). Unmet demand characterises 22% of the census blocks in the study area, clustered in zones with a high population density. The regional GI covers almost completely the two Provinces and the regional parks. In Varese Province: 68% of the territory is included in the regional GI, 82% of the census blocks local demand for recreation opportunities is met, but the population density is higher where the demand is unmet. The Province is characterised by a relatively old population (share of people older than 65 years 23.4%). In Lecco Province, 80% of the territory is included in the regional GI, in 96% of the blocks the local demand is met and the local population is relatively old (share of elderly population 22.12%). The three regional parks present significant differences, strongly influenced by the territorial context. The Campo dei Fiori Park is almost completely included in the regional GI. The entire local population has nature-based recreation opportunities in their close vicinity. Nevertheless, the population density is very low and citizens are relatively old. The majority of the Parco Adda Nord is included in the regional GI providing recreation opportunities to 90% of the census blocks within the Park boundaries. A total of 70% of Ticino Park is included in the regional GI, where local residents are relatively old (share of elderly population 23.78%) and 90% of local census blocks are close to nature-based opportunities. At local scale, we explored how the approach can be used to estimate changes in the CES potential provision and how this can be integrated into a site management plan. This paper demonstrated that the combination of studies in a cross-scale perspective enhances the understanding of GI multifunctionality. It provides a framework to adapt CES mapping models to the local setting with active stakeholders engagement. Moreover, it demonstrates that also highly urbanised areas, such as the Lombardy Region in Italy, can play a role in the deployment of a continental GI and can support biodiversity and nature protection

particle size evaluation of total mixed rations in intensive beef production systems

AbstractSamples of total mixed ration (TMR) were collected periodically in 15 beef cattle farms and submitted to a nutritional and particle size evaluation. Samples of faeces were taken and analysed for pH, consistency, colour and visually ranked for corn residues (Corn Residue Index) from 4 (totally digested) to 0 (very high presence of maize residues). Dry matter (DM), crude protein (CP), and ash content of TMR for Limousine were higher than that for Charolaise while an opposite situation was observed for crude fiber (CF). Particle size analysis of TMR showed an higher content of small ( 19.0 mm) particles in Charolaise than in Limousine TMR. From May to September a general increase of larger fractions and a reduction of the smaller ones were observed, as a consequence of empirical practices of TMR formulation during summer. Faeces characteristics did not show any difference between breeds (overall mean pH: 6.00 vs 6.13; Corn Residue Index: 2.90 vs 3.24, respectively for Charolaise a..

An open multi-physics framework for modelling wildland-urban interface fire evacuations

Fire evacuations at wildland-urban interfaces (WUI) pose a serious challenge to the emergency services, and are a global issue affecting thousands of communities around the world. This paper presents a multi-physics framework for the simulation of evacuation in WUI wildfire incidents, including three main modelling layers: wildfire, pedestrians, and traffic. Currently, these layers have been mostly modelled in isolation and there is no comprehensive model which accounts for their integration. The key features needed for system integration are identified, namely: consistent level of refinement of each layer (i.e. spatial and temporal scales) and their application (e.g. evacuation planning or emergency response), and complete data exchange. Timelines of WUI fire events are analysed using an approach similar to building fire engineering (available vs. required safe egress times for WUI fires, i.e. WASET/WRSET). The proposed framework allows for a paradigm shift from current wildfire risk assessment and mapping tools towards dynamic fire vulnerability mapping. This is the assessment of spatial and temporal vulnerabilities based on the wildfire threat evolution along with variables related to the infrastructure, population and network characteristics. This framework allows for the integration of the three main modelling layers affecting WUI fire evacuation and aims at improving the safety of WUI communities by minimising the consequences of wildfire evacuations