516 research outputs found
Combined application of real-time control and green technologies to urban drainage systems
The increase in waterproof surfaces, a typical phenomenon of urbanization, on the one hand, reduces the volume of rainwater that naturally infiltrates the subsoil and, on the other, it determines the increase in speeds, flow rates, and outflow volume surface; at the same time, it causes a qualitative deterioration of the water. This study researched the optimal management of urban drainage systems via the combined application of real-time control and green technologies. A hydraulic model of the sewer system of the suburbs of Bologna (Italy) was set up using the Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) to evaluate the reduction in water volume and the masses of pollutants discharged in water bodies. The combined application of these technologies allows significantly reducing both the pollutants released into the receiving water bodies and the overflow volumes, while optimizing the operation of the treatment plants. Green technologies cause an average reduction equal to 45% in volume and 53% of total suspended solids (TSS) sent to the receiver. The modeled cases represent only some of the possible configurations achievable on urban drainage systems; the combined use of different solutions could lead to further improvements in the overall functioning of the drainage system
Effect of Homogenous Object Stiffness on Tri-digit Grasp Properties
This paper presents experimental findings on how humans modulate their muscle activity while grasping objects of varying levels of compliance. We hypothesize that one of the key abilities that allows humans to successfully cope with uncertainties while grasping compliant objects is the ability to modulate muscle activity to control both grasp force and stiffness in a way that is coherent with the task. To that end, subjects were recruited to perform a grasp and lift task with a tripod-grasp device with contact surfaces of variable compliance. Subjects performed the task under four different compliance conditions while surface EMG from the main finger flexor and extensor muscles was recorded along with force and torque data at the contact points. Significant increases in the extensor muscle (the antagonist in the task) and co-contraction levels were found with increasing compliance at the contact points. These results suggest that the motor system may employ a strategy of increasing co-contraction, and thereby stiffness, to counteract the decreased stability in grasping compliant objects. Future experiments will examine the extent to which this phenomenon is also related to specific task features, such as precision versus power grasp and object weight
OPTIMIST: A new conflict resolution algorithm for ACT-R.
Several studies have suggested recently that a more dynamic conflict resolution mechanism in the ACT-R cognitive architecture (Anderson & Lebiere, 1998) could improve the decision-making behaviour of cognitive models. This part of ACT-R theory is revisited and a new solution is proposed. The new algorithm (OPTIMIST) has been implemented as an overlay to the ACT-R architecture, and can be used as an alternative mechanism. The operation of the new algorithm is tested in a model of the classical Yerkes and Dodson experiement of animals' learning. When OPTIMIST is used, the resulting model fits the data better than the previous model (e.g. R2 (R squared) increases from .85 to .93 in one example)
Calcium/calmodulin-dependent kinases can regulate the TSH expression in the rat pituitary.
PURPOSE: The endocrine secretion of TSH is a finely orchestrated process
controlled by the thyrotropin-releasing hormone (TRH). Its homeostasis and
signaling rely on many calcium-binding proteins belonging to the "EF-hand"
protein family. The Ca2+/calmodulin (CaM) complex is associated with
Ca2+/CaM-dependent kinases (Ca2+/CaMK). We have investigated Ca2+/CaMK
expression and regulation in the rat pituitary.
METHODS: The expression of CaMKII and CaMKIV in rat anterior pituitary cells was
shown by immunohistochemistry. Cultured anterior pituitary cells were stimulated
by TRH in the presence and absence of KN93, the pharmacological inhibitor of
CaMKII and CaMKIV. Western blotting was then used to measure the expression of
these kinases and of the cAMP response element-binding protein (CREB). TSH
production was measured by RIA after time-dependent stimulation with TRH. Cells
were infected with a lentiviral construct coding for CaMKIV followed by
measurement of CREB phosphorylation and TSH.
RESULTS: Our study shows that two CaM kinases, CaMKII and CaMKII, are expressed
in rat pituitary cells and their phosphorylation in response to TRH occurs at
different time points, with CaMKIV being activated earlier than CaMKII. TRH
induces CREB phosphorylation through the activity of both CaMKII and CaMKIV. The
activation of CREB increases TSH gene expression. CaMKIV induces CREB
phosphorylation while its dominant negative and KN93 exert the opposite effects.
CONCLUSION: Our data indicate that the expression of Ca2+/CaMK in rat anterior
pituitary are correlated to the role of CREB in the genetic regulation of TSH,
and that TRH stimulation activates CaMKIV, which in turn phosphorylates CREB.
This phosphorylation is linked to the production of thyrotropin
Cell-to-Cell Adhesion and Neurogenesis in Human Cortical Development: A Study Comparing 2D Monolayers with 3D Organoid Cultures
SUMMARY
Organoids (ORGs) are increasingly used as models of cerebral cortical development. Here, we compared transcriptome and cellular phenotypes
between telencephalic ORGs and monolayers (MONs) generated in parallel from three biologically distinct induced pluripotent
stem cell (iPSC) lines. Multiple readouts revealed increased proliferation in MONs, which was caused by increased integrin signaling.
MONs also exhibited altered radial glia (RG) polarity and suppression of Notch signaling, as well as impaired generation of intermediate
progenitors, outer RG, and cortical neurons, which were all partially reversed by reaggregation of dissociated cells. Network analyses revealed
co-clustering of cell adhesion, Notch-related transcripts and their transcriptional regulators in a module strongly downregulated in
MONs. The data suggest that ORGs, with respect to MONs, initiate more efficient Notch signaling in ventricular RG owing to preserved
cell adhesion, resulting in subsequent generation of intermediate progenitors and outer RG, in a sequence that recapitulates the cortical
ontogenetic process
Experimentation of a PVA-Borax hydrogel for the removal of Paraloid B72® from artifacts of archaeological interest from the National Archaeological Museum in Naples, Italy
This paper shows the results of an experimentation aimed at the removal of a polymeric film of aged Paraloid B72® originally placed to protect some wooden artifacts belonging to the Egyptian collection of the National Archaeological Museum of Naples (MANN). The study was conducted on two shabtis dated to the 19th Dynasty and a sculpture of Ptah-Sokar-Osiris dating to the late period. Thanks to the collaboration between the National Archaeological Museum of Naples and the Laboratory of Restoration of Wooden Artifacts of the University of Naples Suor Orsola Benincasa, it was possible to conduct an in-depth study of the artifacts, from both an archaeological-historical point of view and from a conservation point of view. This led to the development of the above-mentioned experimentation and to the planning of a proper restoration intervention. The study and experimentation were supported by several diagnostic techniques. In a first stage, non-invasive investigations were carried out to study the execution technique and the state of conservation of the artifacts. This allowed the recognition of the wood species that constituted the three sculptures through optical microscopy, whereas IR reflectography, UV induced fluorescence and X-ray radiation (XRF) were conducted to identify the type and the chemical nature of the pigments. Based on the above analysis, different restoration strategies, based on the removal of Paraloid B72® through a methodology that would act in full respect of the wooden support of the artifacts, were considered. Pros and cons of the different methodologies applied in the recent past for the removal of aged Paraloid from artifact surfaces were analysed. A removal technique based on the use PVA-Borax hydrogel loaded with a solvent mixture was selected. Experiments were conducted to validate the effectiveness of the selected method
Using spectral diversity and heterogeneity measures to map habitat mosaics: An example from the Classical Karst
Questions: Can we map complex habitat mosaics from remote-Âsensing data? In doing
this, are measures of spectral heterogeneity useful to improve image classification
performance? Which measures are the most important? How can multitemporal data
be integrated in a robust framework?
Location: Classical Karst (NE Italy).
Methods: First, a habitat map was produced from field surveys. Then, a collection of
12 monthly Sentinel-Â2 images was retrieved. Vegetation and spectral heterogeneity
(SH) indices were computed and aggregated in four combinations: (1) monthly layers
of vegetation and SH indices; (2) seasonal layers of vegetation and SH indices; (3)
yearly layers of SH indices computed across the months; and (4) yearly layers of SH
indices computed across the seasons. For each combination, a Random Forest clas-
sification was performed, first with the complete set of input layers and then with a
subset obtained by recursive feature elimination. Training and validation points were
independently extracted from field data.
Results: The maximum overall accuracy (0.72) was achieved by using seasonally ag-
gregated vegetation and SH indices, after the number of vegetation types was re-
duced by aggregation from 26 to 11. The use of SH measures significantly increased
the overall accuracy of the classification. The spectral β-Âdiversity was the most im-
portant variable in most cases, while the spectral α-Âdiversity and Rao's Q had a low
relative importance, possibly because some habitat patches were small compared to
the window used to compute the indices.
Conclusions: The results are promising and suggest that image classification frame-
works could benefit from the inclusion of SH measures, rarely included before. Habitat
mapping in complex landscapes can thus be improved in a cost-Âand time-Âeffective
way, suitable for monitoring applications
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