Detailed comfort analysis of the cooling system in the 16th century Villa Aeolia (Costozza, Italy)

The villas of Costozza (Vicenza, Italy), built in 16th century, give an example of bioclimatic architecture actual even today. These villas are connected to a large underground cavities network present inside the nearby hills, that can dissipate heat to the ground and provide cool air in summer. Here is analysed Villa Aeolia, still in operation, modelling its natural cooling system in a day of July by using steady-state 3D Fluid Dynamics computations. We focus on three scenarios depending on the outdoor temperature, that follows the daily temperature variations. The simulations let us to know the indoor velocity field and the temperature distribution in the main hall, the Sala Apollinea. Then, we evaluate the global thermal comfort and local discomfort by determining the sensation index Predicted Mean Vote, Predicted Percentage of Dissatisfied and Draught Rating at 1.1 m above the hall floor. This method can easily be implemented in others cases and allows to have a spatial evaluation of comfort and therefore to identify in the different scenarios which are the parameters on which to act in the event of local discomfort

Stat3-dependent mitochondrial DNA transcription drives stem cells proliferation in zebrafish

The Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor known to be involved in a plethora of physiological processes such as development, differentiation, immunity and metabolism, thus leading to transcription of anti-apoptotic, pro-proliferative and immune response target genes. Importantly, STAT3 pathway was also found aberrantly active in many human pathological conditions including 70% of solid and haematological tumours. With the aim to investigate the putative role of Stat3 in vivo in physiological and pathological conditions, we generated and validated a transgenic line reporting the spatial and temporal expression pattern of canonical Stat3 pathway in zebrafish. It expresses a stabilized form of GFP fluorescent protein under the control of 7 multimerized STAT3 responsive elements from the promoter of the human STAT3 target gene CRP. The characterization of the reporter fluorescent pattern revealed that Stat3 activity is inherited maternally from the oocyte, and that the pathway is active during early developmental stages, in particular in the developing nervous system (telencephalon, optic tectum and hindbrain) from 20 hpf and in the intestine from 4 dpf until adulthood. In these tissues, Stat3 pathway is active in a restricted population of proliferating cells, in which, the chemical inhibition of Stat3 activity results in a significant reduction of the mitotic rate, suggesting that cell division is Stat3-dependent. In particular, in the intestinal epithelium of zebrafish larvae, Stat3 chemical ablation causes the depletion of intestinal folds formation, assessing Stat3 to be necessary for normal intestinal development. The generation of a novel stat3-KO mutant fish by Crispr-Cas9 mutagenesis confirmed the absolute requirement of Stat3 transcription factor for the formation of physiologic intestinal mucosa. In the adult zebrafish, Stat3 activity in the intestine is limited to the Crypt Base Columnar cells, a population of adult stem cells that is actively proliferating in order to sustain intestinal cells turnover. Moreover, in the zebrafish apc- genetic model for human colorectal cancer, Stat3 reporter activity is much increased in the intestinal adenomatous polyps, where it possibly marks the tumour initiating cancer stem cells, thus suggesting Stat3 to be a marker of stemness in the zebrafish. According to some recent data collected in vitro, a limited pool of Stat3 localize to mitochondria, where it acts as a mitochondrial transcription factor inducing proliferation and maintaining pluripotency in ESC. In this work we provide in vivo evidences that mitoStat3 positively regulates embryonic proliferation through expression of mitochondrial genes, and that in zebrafish, mitoStat3 transcriptional activity depends on both Y705 and S727 phosphorylation. In its entirety, our work supports the idea that Stat3 regulates stem cells proliferation through mitochondrial genes expression in zebrafish

Computational Fluid Dynamic Study with Comfort Analysis in Large Atrium of the Angelo Hospital in Venice

To improve the thermal comfort in the hall of the Angelo Hospital (Venezia) an analysis was developed by using Computation Fluid Dynamics and considering some configurations for the air-conditioning system and for the solar shading devices. The reference configuration consists of the installation of four fan coils in the area coupled with a 3 m high metal casing used for solar shading. Then, three other solutions are proposed: by increasing the number of fan coils and changing their position, by adding some radiant panels arranged on the walls, and by inserting a physical confinement as a lateral confinement. The study consists of three sections. Firstly, a section in which the study area is modelled through a strong simplification that allows to represent only a slice of the domain but to immediately evaluate the role of the casing. A second section in which the area is completely modelled, and a third section in which a comfort evaluation is carried out. The analysis shows that the metal casing brings a substantial benefit due to the solar shielding it causes. The radiant panels cool the area only near the wall. The increasing of the number of the fans leads to an excessively high air speed and localized discomfort due to drafts. The lateral confinement on the north and south side is the one that guarantees better cooling of the study area

Digital Tools for the Morphological Design of the Naturally Ventilated Buildings

Naturally ventilated buildings have great potential in terms of comfort and energy saving. However their design is difficult, as the effectiveness of the ventilation is affected by many parameters. Through a parametric CFD (Computational Fluid Dynamics) simulations, graphical tools are generated to evaluate, adopting a comparative approach, the ventilation performance of a morphological family of buildings and to choose the shape of the building, its orientation and the position of the openings. In particular we focus on the interaction between the shape of the building and the wind, that produces a pressure distribution over the building’s envelope, activating an internal airflow through the openings. The pressure difference between any two points lying on the envelope is considered as the force driving of the natural ventilation that depends mainly on the aspect ratio of the building (r) and of its orientation (α). Changing r and α in a specific range, we represent some different configurations. Then we reduce the problem from 3D to 2D, studying the airflow around the vertical and the horizontal cross-section of the building. By knowing the pressure values, we create some plots useful for the positioning of the openings and we calculate an indicator, measuring the global performance of ventilation of the building. By plotting the indicator of the ventilation potential, it is possible to compare the performance of a morphological building family. The graphics can be used by designers without any particular skills in aerodynamics

Tcf7l2 plays pleiotropic roles in the control of glucose homeostasis, pancreas morphology, vascularization and regeneration

Type 2 diabetes (T2D) is a disease characterized by impaired insulin secretion. The Wnt signaling transcription factor Tcf7l2 is to date the T2D-associated gene with the largest effect on disease susceptibility. However, the mechanisms by which TCF7L2 variants affect insulin release from \u3b2-cells are not yet fully understood. By taking advantage of a tcf7l2 zebrafish mutant line, we first show that these animals are characterized by hyperglycemia and impaired islet development. Moreover, we demonstrate that the zebrafish tcf7l2 gene is highly expressed in the exocrine pancreas, suggesting potential bystander effects on \u3b2-cell growth, differentiation and regeneration. Finally, we describe a peculiar vascular phenotype in tcf7l2 mutant larvae, characterized by significant reduction in the average number and diameter of pancreatic islet capillaries. Overall, the zebrafish Tcf7l2 mutant, characterized by hyperglycemia, pancreatic and vascular defects, and reduced regeneration proves to be a suitable model to study the mechanism of action and the pleiotropic effects of Tcf7l2, the most relevant T2D GWAS hit in human populations

The zebrafish orthologue of the human hepatocerebral disease gene MPV17 plays pleiotropic roles in mitochondria

Mitochondrial DNA depletion syndromes (MDS) are a group of rare autosomal recessive disorders with early onset and no cure available. MDS are caused by mutations in nuclear genes involved in mitochondrial DNA (mtDNA) maintenance, and characterized by both a strong reduction in mtDNA content and severe mitochondrial defects in affected tissues. Mutations in MPV17, a nuclear gene encoding a mitochondrial inner membrane protein, have been associated with hepatocerebral forms of MDS. The zebrafish mpv17 null mutant lacks the guanine-based reflective skin cells named iridophores and represents a promising model to clarify the role of Mpv17. In this study, we characterized the mitochondrial phenotype of mpv17-/- larvae and found early and severe ultrastructural alterations in liver mitochondria, as well as significant impairment of the respiratory chain, leading to activation of the mitochondrial quality control. Our results provide evidence for zebrafish Mpv17 being essential for maintaining mitochondrial structure and functionality, while its effects on mtDNA copy number seem to be subordinate. Considering that a role in nucleotide availability had already been postulated for MPV17, that embryos blocked in pyrimidine synthesis do phenocopy mpv17-/- knockouts (KOs) and that mpv17-/- KOs have impaired Dihydroorotate dehydrogenase activity, we provided mpv17 mutants with the pyrimidine precursor orotic acid (OA). Treatment with OA, an easily available food supplement, significantly increased both iridophore number and mtDNA content in mpv17-/- mutants, thus linking the loss of Mpv17 to pyrimidine de novo synthesis and opening a new simple therapeutic approach for MPV17-related MDS

Glucocorticoids promote Von Hippel Lindau degradation and Hif-1α stabilization

Glucocorticoid (GC) and hypoxic transcriptional responses play a central role in tissue homeostasis and regulate the cellular response to stress and inflammation, highlighting the potential for cross-talk between these two signaling pathways. We present results from an unbiased in vivo chemical screen in zebrafish that identifies GCs as activators of hypoxia-inducible factors (HIFs) in the liver. GCs activated consensus hypoxia response element (HRE) reporters in a glucocorticoid receptor (GR)-dependent manner. Importantly, GCs activated HIF transcriptional responses in a zebrafish mutant line harboring a point mutation in the GR DNA-binding domain, suggesting a nontranscriptional route for GR to activate HIF signaling. We noted that GCs increase the transcription of several key regulators of glucose metabolism that contain HREs, suggesting a role for GC/HIF cross-talk in regulating glucose homeostasis. Importantly, we show that GCs stabilize HIF protein in intact human liver tissue and isolated hepatocytes. We find that GCs limit the expression of Von Hippel Lindau protein (pVHL), a negative regulator of HIF, and that treatment with the c-src inhibitor PP2 rescued this effect, suggesting a role for GCs in promoting c-src–mediated proteosomal degradation of pVHL. Our data support a model for GCs to stabilize HIF through activation of c-src and subsequent destabilization of pVHL

Stat3-dependent mitochondrial DNA transcription drives stem cells proliferation in zebrafish

The Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor known to be involved in a plethora of physiological processes such as development, differentiation, immunity and metabolism, thus leading to transcription of anti-apoptotic, pro-proliferative and immune response target genes. Importantly, STAT3 pathway was also found aberrantly active in many human pathological conditions including 70% of solid and haematological tumours. With the aim to investigate the putative role of Stat3 in vivo in physiological and pathological conditions, we generated and validated a transgenic line reporting the spatial and temporal expression pattern of canonical Stat3 pathway in zebrafish. It expresses a stabilized form of GFP fluorescent protein under the control of 7 multimerized STAT3 responsive elements from the promoter of the human STAT3 target gene CRP. The characterization of the reporter fluorescent pattern revealed that Stat3 activity is inherited maternally from the oocyte, and that the pathway is active during early developmental stages, in particular in the developing nervous system (telencephalon, optic tectum and hindbrain) from 20 hpf and in the intestine from 4 dpf until adulthood. In these tissues, Stat3 pathway is active in a restricted population of proliferating cells, in which, the chemical inhibition of Stat3 activity results in a significant reduction of the mitotic rate, suggesting that cell division is Stat3-dependent. In particular, in the intestinal epithelium of zebrafish larvae, Stat3 chemical ablation causes the depletion of intestinal folds formation, assessing Stat3 to be necessary for normal intestinal development. The generation of a novel stat3-KO mutant fish by Crispr-Cas9 mutagenesis confirmed the absolute requirement of Stat3 transcription factor for the formation of physiologic intestinal mucosa. In the adult zebrafish, Stat3 activity in the intestine is limited to the Crypt Base Columnar cells, a population of adult stem cells that is actively proliferating in order to sustain intestinal cells turnover. Moreover, in the zebrafish apc- genetic model for human colorectal cancer, Stat3 reporter activity is much increased in the intestinal adenomatous polyps, where it possibly marks the tumour initiating cancer stem cells, thus suggesting Stat3 to be a marker of stemness in the zebrafish. According to some recent data collected in vitro, a limited pool of Stat3 localize to mitochondria, where it acts as a mitochondrial transcription factor inducing proliferation and maintaining pluripotency in ESC. In this work we provide in vivo evidences that mitoStat3 positively regulates embryonic proliferation through expression of mitochondrial genes, and that in zebrafish, mitoStat3 transcriptional activity depends on both Y705 and S727 phosphorylation. In its entirety, our work supports the idea that Stat3 regulates stem cells proliferation through mitochondrial genes expression in zebrafish.Il fattore trascrizionale STAT3 (Signal Transducer and Activator of Transcription 3), è noto per essere coinvolto in una varietà di processi fisiologici tra i quali lo sviluppo, il differenziamento cellulare, l’immunità e il metabolismo, attraverso la regolazione dell’espressione di geni target anti-apoptotici, pro-proliferativi e coinvolti nei meccanismi di risposta immunitaria. Inoltre, è stata osservata l’attivazione ectopica della via di segnale STAT3 in numerose patologie umane che includono il 70% dei tumori sia solidi che ematologici. Con lo scopo di studiare in vivo il ruolo di Stat3 sia in condizioni fisiologiche che nel processo di patogenesi, è stata generata una linea transgenica biosensore della via canonica di segnale Stat3, in grado di riportarne l’attivazione spaziale e temporale nell’organismo modello zebrafish. Essa esprime la proteina fluorescente verde EGFP sotto il controllo di 7 elementi ripetuti in tandem contenenti le sequenze responsive a Stat3; tali elementi, sono stati ottenuti dal promotore del gene CRP di uomo, un noto bersaglio dell’attività trascrizionale di Stat3. La caratterizzazione del segnale fluorescente del pesce reporter ha dimostrato che la proteina Stat3 manifesta effetto materno, essendo ereditata dallo zigote a partire dall’oocita della madre; inoltre, la via di segnale è attiva durante le prime fasi dello sviluppo di zebrafish, in particolare nel sistema nervoso (telencefalo, tetto ottico e cervello posteriore) dalle 20 ore dopo la fecondazione, e nell’intestino a partire dai 4 giorni fino all’età adulta. In entrambi questi tessuti il segnale reporter marca cellule proliferanti, che a seguito della somministrazione di inibitori chimici della via di segnale Stat3 riducono significativamente la loro attività mitotica, suggerendo che il processo di divisione cellulare dipende da Stat3 durante lo sviluppo di zebrafish. In particolare nell’epitelio intestinale delle larve, l’inibizione chimica della via di segnale Stat3 causa difetti nella formazione dei villi intestinali, rivelando che Stat3 è necessario per il corretto sviluppo dell’epitelio intestinale in zebrafish. Tale risultato è stato avvalorato a seguito della creazione di un mutante KO per il gene stat3, il quale ha confermato l’assoluta necessità della proteina Stat3 per la formazione della normale mucosa intestinale. Nell’intestino di zebrafish adulti l’attività della via di segnale Stat3 è limitata ad una ristretta popolazione di cellule staminali adulte localizzate alla base della cripta, che proliferano attivamente per garantire il ricambio cellulare tipico di questo tessuto. Inoltre, nello zebrafish modello per il tumore colon-rettale umano, caratterizzato da una mutazione al gene apc, l’attività della via di segnale Stat3 riportata dal pesce reporter è significativamente maggiore nei polipi adenomatosi, dove verosimilmente è attiva nelle cellule staminali tumorali iniziatrici del cancro; tali risultati suggeriscono per Stat3 un ruolo come marcatore di staminalità in zebrafish. Secondo alcune recenti pubblicazioni basate su dati ottenuti in vitro, una quantità limitata di proteina STAT3 è stata localizzata nel mitocondrio, dove agisce come fattore trascrizionale mitocondriale, inducendo la proliferazione e mantenendo la pluripotenza delle cellule staminali embrionali di topo. In questo lavoro vengono presentati dati ottenuti in vivo, a dimostrazione che mitoStat3 regola positivamente il processo proliferativo attraverso l’espressione di geni mitocondriali; si è inoltre dimostrato che l’attività trascrizionale di mitoStat3 dipende dalla fosforilazione ad entrambi gli amminoacidi Y705 e S727. Nel suo complesso il nostro lavoro dimostra che il fattore trascrizionale Stat3 è in grado di regolare la proliferazione nelle cellule staminali attraverso l’espressione di geni mitocondriali in zebrafish

Ancient Use of Natural Geothermal Resources : Analysis of Natural Cooling of 16th Century Villas in Costozza (Italy) as a Reference for Modern Buildings

The geothermal cooling system of six villas of the 16th century in Costozza (Vicenza, Italy) is analysed and modeled by using Computational Fluid Dynamics and referring to in-field monitoring data. The system passively cools the villas in summertime by means of underground ducts connected to the caves present in the nearby hills. It still perfectly works in Villa Aeolia, that is here analysed in more detail. The outcomes permit to understand in a better way the functioning conditions and to improve the conservation of the villas as a whole. Furthermore the ancient cooling system can be used as a reference of how geothermal renewable resources can be used to improve the indoor comfort and limit the energy consumption also in modern new buildings in a temperate climate. extbf{On one side a macroscopic analysis of the global airflow system and on the other side a detailed analysis on Villa Aeolia are developed. All results are validated with analytical methods, numerical methods and with the past experimental records. The system can provide fresh airflow rates that cool the walls of the room and maintain the temperature below 20$^circ$C even on hot summer days. The system is adaptive, the airflow increases when the outdoor temperature increases. This self-adjustment allows us to compare the cooling system to a modern environmental control system