An Experience on Environmental Education based on Respect-Reduce-Reuse-Recycle in a Village Primary School in the Marche Region, in Italy

T he importance of environmental educatio n is widely recognized worldwide: an important objective is that the citizens are accustomed to apply the best available practices in their life , while ask ing the administration and the government to gradually enforce measures lead ing to a reduction of the environmental impact and to a more sustainable lifestyle. This requires a formation starting at an early age: however, in Italy the relevant indications from the National Curriculum are still limited and do not suggest explicitly the performance of any pr actical activity , tailored on the specific school setting . This inadequacy of the Curriculum becomes particularly apparent in cases where other concerns are present, for example the areas in the Marche region affected by the 2016 earthquake : here, the need to resum e a day by day routine put a kind of \u201cdamper\u201d on other questions, such as environmental issues . This had an effect also i n children\u2019s life on this question, school needs to take a stand , which is the objective of this study . This work concerns an approach to environmental education in a multi classes primary school context (age 6 10) in a small village school, located in the Central Apennine in Italy. This is performed through an experience carried out by investigating the behavior towards waste p roduction of the community, as perceived by children at school. It is therefore articulated through the application of 4R (Respect, which encompasses Reduce, Reuse and Recycle) applying and extending the indications from the Italian National Curriculum. Th e project leads also to an experience of self production of objects by the use of waste, to improve their awareness of the possibilities included in their upcycling. Feedback on the experience is finally acquired from the children and discussed, especially in the sense of creating future citizens with a more sensible and reasonable behavior towards the environment and leading possibly to zero waste strategies in their family and work setting. The data were analy z ed using thematic analysis and different them es about waste production were singled out

An Experience on Environmental Education Based on Respect-Reduce-Reuse-Recycle in a Village Primary School in the Marche Region, in Italy

The importance of environmental education is widely recognized worldwide: an important objective is that the citizens are accustomed to apply the best available practices in their life, while asking the administration and the government to gradually enforce measures leading to a reduction of the environmental impact and to a more sustainable lifestyle. This requires a formation starting at an early age: however, in Italy the relevant indications from the National Curriculum are still limited and do not suggest explicitly the performance of any practical activity, tailored on the specific school setting. This inadequacy of the Curriculum becomes particularly apparent in cases where other concerns are present, for example the areas in the Marche region affected by the 2016 earthquake: here, the need to resume a day-by-day routine put a kind of “damper” on other questions, such as environmental issues. This had an effect also in children’s life: on this question, school needs to take a stand, which is the objective of this study. This work concerns an approach to environmental education in a multi-classes primary school context (age 6-10) in a small village school, located in the Central Apennine in Italy. This is performed through an experience carried out by investigating the behavior towards waste production of the community, as perceived by children at school. It is therefore articulated through the application of 4R (Respect, which encompasses Reduce, Reuse and Recycle) applying and extending the indications from the Italian National Curriculum. The project leads also to an experience of self-production of objects by the use of waste, to improve their awareness of the possibilities included in their upcycling. Feedback on the experience is finally acquired from the children and discussed, especially in the sense of creating future citizens with a more sensible and reasonable behavior towards the environment and leading possibly to zero-waste strategies in their family and work setting. The data were analyzed using thematic analysis and different themes about waste production were singled out

Dynamical Properties of Molecular-forming Gas Clumps in Galaxies at the Epoch of Reionization

We study the properties of molecular-forming gas clumps (MGCs) at the epoch of reionization using cosmological zoom-in simulations. We identify MGCs in a z=6 prototypical galaxy ("Althaea") using an H2 density-based clump finder. We compare their mass, size, velocity dispersion, gas surface density, and virial parameter (alpha_vir) to observations. In Althaea, the typical MGC mass and size are Mgas=10^6.5 Msun and R=45-100 pc, which are comparable to those found in nearby spirals and starburst galaxies. MGCs are highly supersonic and supported by turbulence, with rms velocity dispersions of sigma_gas=20-100 km s^-1 and pressure of P/k_B=10^7.6 K cm^-3 (i.e., >1000x with respect to the Milky Way), similar to those found in nearby and z~2 gas-rich starburst galaxies. In addition, we perform stability analysis to understand the origin and dynamical properties of MGCs. We find that MGCs are globally stable in the main disk of Althaea. Densest regions where star formation is expected to take place in clouds and cores on even smaller scales instead have lower alpha_vir and Toomre-Q values. Detailed studies of the star-forming gas dynamics at the epoch of reionization thus require a spatial resolution of <40 pc (=0.01"), which is within reach with the Atacama Large (sub-)Millimeter Array and the Next Generation Very Large Array.Comment: 16 pages, 10 figures, ApJ accepte

The black hole and host galaxy growth in an isolated z∼6z\sim 6 QSO observed with ALMA

The outstanding mass growth of supermassive black holes (SMBHs) at the Reionisation Epoch and how it is related to the concurrent growth of their host galaxies, poses challenges to theoretical models aimed at explaining how these systems formed in short timescales (<1 Gyr). To trace the average evolutionary paths of quasi-stellar objects (QSOs) and their host galaxies in the BH mass-host mass ($M_{\rm dyn}$) plane, we compare the star formation rate (SFR), derived from the accurate estimate of the dust temperature and the dust mass ($T_{\rm dust}, M_{\rm dust}$), with the BH accretion rate. To this aim, we analysed a deep, $900$ pc resolution ALMA observation of the sub-mm continuum, [CII] and H$_2$O of the $z\sim 6$ QSO J2310+1855, enabling a detailed study of dust properties and cold gas kinematics. We performed an accurate SED analysis obtaining a dust temperature of $T_{\rm dust} = 71$ K and a dust mass of $M_{\rm dust}= 4.4 \times 10^8\ \rm M_{\odot}$. The implied AGN-corrected SFR is $1240 \ \rm M_{\odot}yr^{-1}$, a factor of 2 smaller than previously reported for this QSO. We derived the best estimate of the dynamical mass $M_{\rm dyn} = 5.2\times 10^{10}\ \rm M_{\odot}$ within $r = 1.7$ kpc, based on a dynamical model of the system. We found that ${\rm SFR}/M_{\rm dyn}>\dot M_{\rm BH}/M_{\rm BH}$, suggesting that AGN feedback might be efficiently acting to slow down the SMBH accretion, while the stellar mass assembly is still vigorously taking place in the host galaxy. In addition, we were also able to detect high-velocity emission on the red and blue sides of the [CII] emission line, that traces a gaseous outflow, and for the first time, we mapped a spatially-resolved water vapour disk through the H$_2$O v=0 $3_{(2,2)}-3_{(1,3)}$ emission line detected at $\nu_{\rm obs} = 274.074$ GHz, whose kinematic properties and size are broadly consistent with those of the [CII] disk.Comment: 15 pages, 10 figures, 4 tables. Accepted in A&

Black hole and host galaxy growth in an isolated z 6 QSO observed with ALMA

The outstanding mass growth of supermassive black holes (SMBHs) at the epoch of reionisation and its relation to the concurrent growth of their host galaxies poses challenges to theoretical models aimed at explaining how these systems formed on short timescales (&lt; 1 Gyr). To trace the average evolutionary paths of quasi-stellar objects (QSOs) and their host galaxies in the plane of BH mass to host mass (Mdyn), we compare the star formation rate (SFR), derived from the accurate estimate of the dust temperature and the dust mass (Tdust, Mdust) based on infrared and sub-millimeter (sub-mm) spectral energy distribution (SED), with the BH accretion rate, derived from Lbol based on X-ray and optical and ultraviolet SED. To this aim, we analysed a deep ALMA observation of the sub-mm continuum, [CII], and H2O of the z ∼ 6 QSO J2310+1855 with a resolution of 900 pc, which enabled a detailed study of dust properties and cold gas kinematics. We performed an accurate SED analysis obtaining a dust temperature of Tdust = 71 ± 4 K, dust mass Mdust = (4.4 ± 0.7)×108 M⊙, and total far-infrared luminosity of LTIR = 2.5−0.5+0.6 × 1013 L⊙. The implied active galactic nuclei (AGN) – corrected SFR = 1240−260+310 M⊙ yr−1 is a factor of 2 lower than previously reported for this QSO. We measured a gas-to-dust ratio of GDR = 101 ± 20. The dust continuum and [CII] surface brightness profiles are spatially extended out to r ∼ 6.7 kpc and r ∼ 5 kpc, respectively, with half-light radii of 0.9 and 1.1 kpc for the dust and gas, respectively. The derived gas surface density, Σgas, and star formation rate density, ΣSFR, place the J2310+1855 host galaxy above the Kennicutt-Schmidt relation. We derived a best estimate of the dynamical mass Mdyn = 5.2 × 1010 M⊙ within r = 1.7 kpc based on a dynamical model of the system with a rotating disk inclined at i = 25 deg. The Toomre parameter profile across the disk is Qgas ∼ 3 and implies that the disk is unstable. We found that SFR/Mdyn &gt; ṀBH/MBH, suggesting that AGN feedback might be efficiently acting to slow down the SMBH accretion, while stellar mass assembly is still vigorously taking place in the host galaxy. In addition, we were also able to detect high-velocity emission on the red and blue sides of the [CII] emission line that is not consistent with disk rotation and traces a gaseous outflow. We derived an outflow mass Mout = 3.5 × 108 M⊙, and a mass outflow rate in the range Ṁout = 1800 − 4500 M⊙ yr−1. The implied Ėout ∼ 0.0005 − 0.001 Lbol is in agreement with the values observed for ionised winds. For the first time, we mapped a spatially resolved water vapour disk through the H2O v = 0 3(2, 2) − 3(1, 3) emission line detected at νobs = 274.074 GHz, whose kinematic properties and size are broadly consistent with those of the [CII] disk. The luminosity ratio LH2O/LTIR = 1.4 × 10−5 is consistent with line excitation by dust-reprocessed star formation in the interstellar medium of the host galaxy

Metal Enrichment in the Reionization Epoch

The presence of elements heavier than helium ("metals") is of fundamental importance for a large number of astrophysical processes occurring in planet, star and galaxy formation; it also affects cosmic structure formation and evolution in several ways. Even a small amount of heavy elements can dramatically alter the chemistry of the gas, opening the path to complex molecules. Metals might enhance the ability of the gas to radiate away its thermal energy, thus favoring the formation of gravitationally bound objects; they can also condensate in a solid phase (dust grains), partly or totally blocking radiation from luminous sources. Finally, they represent useful tracers of energy deposition by stars and probe the physical properties of the environment by absorption or emission lines. Last, but certainly not least, life -- as we know it on Earth -- is tightly related to the presence of at least some of the heavy elements. In this pedagogical review I will concentrate on the connection between early metal enrichment and cosmic reionization. As we will see these two processes are intimately connected and their joint study might turn out to be fundamental in understanding the overall evolution of the Universe during the first billion years after the Big Bang, an epoch corresponding to redshifts z>6.Comment: Book chapter in Understanding the Epoch of Cosmic Reionization: Challenges and Progress, Springer International Publishing, Ed. Andrei Mesinger, ISBN 978-3-319-21956-1. arXiv admin note: text overlap with arXiv:astro-ph/0007248 by other author

Dolichol: A Component of the Cellular Antioxidant Machinery

Dolichol, an end product of the mevalonate pathway, has been proposed a biomarker of aging, but its biological role, not to mention its catabolism, has not been fully understood. UV-B radiation was used to induce oxidative stress in isolated rat hepatocytes by the collagenase method. Effects on dolichol, phospholipids-bound polyunsaturated fatty acids (PL PUFA) and known lipid soluble antioxidants [coenzyme Q (CoQ) and α-tocopherol] were studied. The increase in oxidative stress was detected by a probe sensitive to reactive oxygen species (ROS). Peroxidation of lipids was assessed by measuring the release of thiobarbituric acid reactive substances (TBARS). Dolichol, CoQ and α-tocopherol were assessed by high-pressure liquid chromatography (HPLC), PL PUFA by gas-liquid chromatography (GC). UV-B radiation caused an immediate increase in ROS as well as lipid peroxidation and a simultaneous decrease in the levels of dolichol and lipid soluble antioxidants. Decrease in dolichol paralleled changes in CoQ levels and was smaller than that in α-tocopherol. The addition of mevinolin, a competitive inhibitor of the enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoAR), magnified the loss of dolichol and was associated with an increase in TBARS production. Changes in PL PUFA were minor. These findings highlight that oxidative stress has very early and similar effects on dolichol and lipid soluble antioxidants. Lower levels of dolichol are associated with enhanced peroxidation of lipids, which suggest that dolichol may have a protective role in the antioxidant machinery of cell membranes and perhaps be a key to understanding some adverse effects of statin therapy

Unveiling [CII] clumps in a lensed star-forming galaxy at z ~ 3.4

Observations at UV and optical wavelengths have revealed that galaxies at z~1-4 host star-forming regions, dubbed "clumps", which are believed to form due to the fragmentation of gravitationally unstable, gas-rich disks. However, the detection of the parent molecular clouds that give birth to such clumps is still possible only in a minority of galaxies, mostly at z~1. We investigated the [CII] and dust morphology of a z~3.4 lensed galaxy hosting four clumps detected in the UV continuum. We aimed to observe the [CII] emission of individual clumps that, unlike the UV, is not affected by dust extinction, to probe their nature and cold gas content. We conducted ALMA observations probing scales down to ~300 pc and detected three [CII] clumps. One (dubbed "NE") coincides with the brightest UV clump, while the other two ("SW" and "C") are not detected in the UV continuum. We do not detect the dust continuum. We converted the [CII] luminosity of individual clumps into molecular gas mass and found Mmol~10^8 Msun. By complementing it with the star formation rate (SFR) estimate from the UV continuum, we estimated the gas depletion time (tdep) of clumps and investigated their location in the Schmidt-Kennicutt plane. While the NE clump has a short tdep=0.16 Gyr, comparable with high-redshift starbursts, the SW and C clumps instead have longer tdep>0.65 Gyr and are likely probing the initial phases of star formation. The lack of dust continuum detection is consistent with the blue UV continuum slope estimated for this galaxy (beta~-2.5) and it indicates that dust inhomogeneities do not significantly affect the detection of UV clumps in this target. We pushed the observation of the cold gas content of individual clumps up to z~3.4 and showed that the [C II] line emission is a promising tracer of molecular clouds at high redshift, allowing the detection of clumps with a large range of depletion times.Comment: Accepted for publication in A&

The ALMA REBELS Survey: The First Infrared Luminosity Function Measurement at $\mathbf{z \sim 7}

We present the first observational infrared luminosity function (IRLF) measurement in the Epoch of Reionization (EoR) based on a UV-selected galaxy sample with ALMA spectroscopic observations. Our analysis is based on the ALMA large program Reionization Era Bright Emission Line Survey (REBELS), which targets 42 galaxies at $\mathrm{z=6.4-7.7}$ with [CII] 158\micron line scans. 16 sources exhibit a dust detection, 15 of which are also spectroscopically confirmed through the [CII] line. The IR luminosities of the sample range from $\log L_{IR}/L_\odot=11.4$ to 12.2. Using the UVLF as a proxy to derive the effective volume for each of our target sources, we derive IRLF estimates, both for detections and for the full sample including IR luminosity upper limits. The resulting IRLFs are well reproduced by a Schechter function with the characteristic luminosity of $\log L_{*}/L_\odot=11.6^{+0.2}_{-0.1}$. Our observational results are in broad agreement with the average of predicted IRLFs from simulations at $z\sim7$. Conversely, our IRLFs lie significantly below lower redshift estimates, suggesting a rapid evolution from $z\sim4$ to $z\sim7$, into the reionization epoch. The inferred obscured contribution to the cosmic star-formation rate density at $z\sim7$ amounts to $\mathrm{log(SFRD/M_{\odot}/yr/Mpc^{3}) = -2.66^{+0.17}_{-0.14} }$ which is at least $\sim$10\% of UV-based estimates. We conclude that the presence of dust is already abundant in the EoR and discuss the possibility of unveiling larger samples of dusty galaxies with future ALMA and JWST observations.Comment: 9 pages, 5 figure

The ALMA REBELS Survey: the first infrared luminosity function measurement at z ∼ 7

We present the first observational infrared luminosity function (IRLF) measurement in the Epoch of Reionization (EoR) based on a ultraviolet (UV)-selected galaxy sample with the Atacama Large Millimeter Array (ALMA) spectroscopic observations. Our analysis is based on the ALMA large program Reionization Era Bright Emission Line Survey (REBELS), which targets 42 galaxies at z = 6.4–7.7 with [C II] 158 μm line scans. 16 sources exhibit dust detection, 15 of which are also spectroscopically confirmed through the [C II] line. The infrared (IR) luminosities of the sample range from log LIR/L⊙ = 11.4 to 12.2. Using the UV luminosity function as a proxy to derive the effective volume for each of our target sources, we derive IRLF estimates, both for detections and for the full sample including IR luminosity upper limits. The resulting IRLFs are well reproduced by a Schechter function with the characteristic luminosity of logL∗/L⊙=11.6+0.2−0.1 . Our observational results are in broad agreement with the average of predicted IRLFs from simulations at z ∼ 7. Conversely, our IRLFs lie significantly below lower redshift estimates, suggesting a rapid evolution from z ∼ 4 to z ∼ 7, into the reionization epoch. The IR obscured contribution to the cosmic star formation rate density at z ∼ 7 amounts to log(SFRD/M⊙yr−1Mpc−3)=−2.66+0.17−0.14 that is at least ∼10 per cent of UV-based estimates. We conclude that the presence of dust is already abundant in the EoR and discuss the possibility of unveiling larger samples of dusty galaxies with future ALMA and JWST observations