1,087 research outputs found
Integration of New Technologies and Alternative Methods in Laboratory-Based Scenarios
In this study, we report a preliminary requirements analysis to recognize needs and possibilities for integrating new technologies and methods for lab-based learning in the field of Industry 4.0 and Internet of Things. To this aim, different scenarios, such as real, remote and virtual labs, are considered to be addressable within an integrated learning environment that focuses on alternative methods (i.e. Serious Games, Self-Regulated and Collaborative Learning) and new technologies (i.e. Open Badges, Mixed Reality and Learning Analytics). To support the design of the laboratory-based learning environment, qualitative interviews were conducted with both expert lecturers and relevant students in the field of engineering, to provide complementary perspectives. These interviews were carried out to analyze the requirements, and to identify possible benefits that relevant stakeholders expect by using these teaching and learning methods and technologies. A qualitative content analysis has been started on the interviews to define which is the perception of the new technologies and teaching methods. The different points of view about technologies and methods coming from expert lecturers’ and relevant students’ interviews are provided
Automated simulation of areal bone mineral density assessment in the distal radius from high-resolution peripheral quantitative computed tomography
SummaryAn automated image processing method is presented for simulating areal bone mineral density measures using high-resolution peripheral quantitative computed tomography (HR-pQCT) in the ultra-distal radius. The accuracy of the method is validated against clinical dual X-ray absorptiometry (DXA). This technique represents a useful reference to gauge the utility of novel 3D quantification methods applied to HR-pQCT in multi-center clinical studies and potentially negates the need for separate forearm DXA measurements.IntroductionOsteoporotic status is primarily assessed by measuring areal bone mineral density (aBMD) using 2D dual X-ray absorptiometry (DXA). However, this technique does not sufficiently explain bone strength and fracture risk. High-resolution peripheral quantitative computed tomography (HR-pQCT) has been introduced as a method to quantify 3D bone microstructure and biomechanics. In this study, an automated method is proposed to simulate aBMD measures from HR-pQCT distal radius images.MethodsA total of 117 subject scans were retrospectively analyzed from two clinical bone quality studies. The distal radius was imaged by HR-pQCT and DXA on one of two devices (Hologic or Lunar). Areal BMD was calculated by simulation from HR-pQCT images (aBMD(sim)) and by standard DXA analysis (aBMD(dxa)).ResultsThe reproducibility of the simulation technique was 1.1% (root mean-squared coefficient of variation). HR-pQCT-based aBMD(sim) correlated strongly to aBMD(dxa) (Hologic: R (2) = 0.82, Lunar: R (2) = 0.87), though aBMD(sim) underestimated aBMD(dxa) for both DXA devices (p < 0.0001). Finally, aBMD(sim) predicted aBMD at the proximal femur and lumbar spine with equal power compared to aBMD(dxa).ConclusionThe results demonstrate that aBMD can be simulated from HR-pQCT images of the distal radius. This approach has the potential to serve as a surrogate forearm aBMD measure for clinical HR-pQCT studies when axial bone mineral density values are not required
Quantum Criticality in doped CePd_1-xRh_x Ferromagnet
CePd_1-xRh_x alloys exhibit a continuous evolution from ferromagnetism (T_C=
6.5 K) at x = 0 to a mixed valence (MV) state at x = 1. We have performed a
detailed investigation on the suppression of the ferromagnetic (F) phase in
this alloy using dc-(\chi_dc) and ac-susceptibility (\chi_ac), specific heat
(C_m), resistivity (\rho) and thermal expansion (\beta) techniques. Our results
show a continuous decrease of T_C (x) with negative curvature down to T_C = 3K
at x*= 0.65, where a positive curvature takes over. Beyond x*, a cusp in cac is
traced down to T_C* = 25 mK at x = 0.87, locating the critical concentration
between x = 0.87 and 0.90. The quantum criticality of this region is recognized
by the -log(T/T_0) dependence of C_m/T, which transforms into a T^-q (~0.5) one
at x = 0.87. At high temperature, this system shows the onset of valence
instability revealed by a deviation from Vegard's law (at x_V~0.75) and
increasing hybridization effects on high temperature \chi_dc and \rho.
Coincidentally, a Fermi liquid contribution to the specific heat arises from
the MV component, which becomes dominant at the CeRh limit. In contrast to
antiferromagnetic systems, no C_m/T flattening is observed for x > x_cr rather
the mentioned power law divergence, which coincides with a change of sign of
\beta. The coexistence of F and MV components and the sudden changes in the T
dependencies are discussed in the context of randomly distributed magnetic and
Kondo couplings.Comment: 11 pages, 11 figure
Rough-and-tumble play as a window on animal communication.
Rough-and-tumble play (RT) is a widespread phenomenon in mammals. Since it involves competition, whereby one
animal attempts to gain advantage over another, RT runs the risk of escalation to serious fighting. Competition is
typically curtailed by some degree of cooperation and different signals help negotiate potential mishaps during RT. This
review provides a framework for such signals, showing that they range along two dimensions: one from signals borrowed
from other functional contexts to those that are unique to play, and the other from purely emotional expressions to
highly cognitive (intentional) constructions. Some animal taxa have exaggerated the emotional and cognitive interplay
aspects of play signals, yielding admixtures of communication that have led to complex forms of RT. This complexity
has been further exaggerated in some lineages by the development of specific novel gestures that can be used to
negotiate playful mood and entice reluctant partners. Play-derived gestures may provide new mechanisms by which
more sophisticated communication forms can evolve. Therefore, RT and playful communication provide a window
into the study of social cognition, emotional regulation and the evolution of communication systems
Fluid moment hierarchy equations derived from quantum kinetic theory
A set of quantum hydrodynamic equations are derived from the moments of the
electrostatic mean-field Wigner kinetic equation. No assumptions are made on
the particular local equilibrium or on the statistical ensemble wave functions.
Quantum diffraction effects appear explicitly only in the transport equation
for the heat flux triad, which is the third-order moment of the Wigner
pseudo-distribution. The general linear dispersion relation is derived, from
which a quantum modified Bohm-Gross relation is recovered in the long
wave-length limit. Nonlinear, traveling wave solutions are numerically found in
the one-dimensional case. The results shed light on the relation between
quantum kinetic theory, the Bohm-de Broglie-Madelung eikonal approach, and
quantum fluid transport around given equilibrium distribution functions.Comment: 5 pages, three figures, uses elsarticle.cl
Chemical Defense of an Asian Snake Reflects Local Availability of Toxic Prey and Hatchling Diet
Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (nuchal glands\u27), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R.tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles from toad-rich Ishima Island that had not been fed toads possess defensive bufadienolides in their nuchal glands, presumably due to maternal provisioning of these sequestered compounds. Wild-caught juveniles from Ishima possess large quantities of bufadienolides, which could result from a combination of maternal provisioning and sequestration of these defensive compounds from consumed toads. Interestingly, juvenile females from Ishima possess larger quantities of bufadienolides than do juvenile males, whereas a small sample of field-collected snakes suggests that adult males contain larger quantities of bufadienolides than do adult females. Captive-born hatchlings from Kinkasan Island lack bufadienolides in their nuchal glands, reflecting the absence of toads on that island, but they can sequester bufadienolides by feeding on toads (Bufo japonicus) in captivity. The presence of large quantities of bufadienolides in the nuchal glands of R.tigrinus from Ishima may reduce the risk of predation by providing an effective chemical defense, whereas snakes on Kinkasan may experience increased predation due to the lack of defensive compounds in their nuchal glands
Chemical Basis of Prey Recognition in Thamnophiine Snakes: The Unexpected New Roles of Parvalbumins
Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO). In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins–parvalbumins–present in the cutaneous mucus of the common frog (Rana temporaria) may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca2+ buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca2+-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction
Ohio Conservation Plan: Plains gartersnake, Thamnophis radix
This plan outlines strategies and methods used in an ongoing study initiated in 1999 to restore a selfsustaining population of the Plains gartersnake (Thamnophis radix) in Ohio. Restoring a self-sustaining population would require increases in the current population to where the ratios of T. radix to T. sirtalis are approximately 1:1 in multiple locations in Killdeer Plains Wildlife Area (KPWA). This ratio would be similar to what was seen earlier by Reichenbach and Dalrymple (1986) at one site in KPWA.
The plan was developed by a team of enthusiastic conservationists representing, the Division of Wildlife (ODW), the Columbus and Cleveland Zoos, Westerville North High School Field Study Class, Liberty University, Northern Illinois University, and the University of Tennessee. A thorough review of the plan will be made in 2012 with revisions and updates as needed
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