772 research outputs found
The effects of delay of reinforcement on subsequent running behavior under immediate reinforcement
In a variety of leaning situations, delay of reinforcement has been found to result in a lower level of responding. There is some question whether the asymptote of learning or only the rate of approach to asymptote is affected by delay. In addition, delay of reinforcement has been shown to increase resistance to extinction
Dislocations
`Dislocations' is a series of three textile works, created by Armando Chant in collaboration with Donna Sgro. The works were presented as part of Interwoven which is a curated selection of fashion and textile works of the Design Institute of Australia Textile Practice Group. `Dislocations' investigates the biological phenomena of patterning that is evident in butterfly wing growth, and the resulting structural distortion in the pattern that develops. The textile works were an investigation of this structural principle through their constructed methodology. The three works were hand-screenprinted in monochromatic half-tones, sliced and re-constructed through stitching, emphasizing the disruptive nature of the pattern. The works are an investigation into the creation of `constructed disruptive imagery' using a biomimetic methodology. Disruptive imagery has been developed in relation to textiles in the area of camouflage. Camouflage is a biomimetic adaptation where pattern is used to cloak what is seen. Using a different principle of disruptive imagery, this work investigates how other biomimetic adaptations may be used to disrupt the visual within a textiles context. Interwoven was exhibited at the Design Gallery of the DIA Head Office and promoted to members of the DIA nationally as part of LOOK.STOP.SHOP, a Melbourne Spring Fashion Week event
Subacute thyroiditis after Sars-COV-2 infection
Context: Subacute thyroiditis (SAT) is a thyroid disease of viral or postviral origin. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that began in Wuhan, China, has spread rapidly worldwide and Italy has been severely affected by this outbreak. Objectives: The objective of this work is to report the first case of SAT related to SARS-CoV-2 infection. Methods: We describe the clinical, laboratory, and imaging features of an 18-year-old woman who came to our attention for fever, neck pain radiated to the jaw, and palpitations occurring 15 days after a SARS-CoV-2-positive oropharyngeal swab. Coronavirus disease 2019 (COVID-19) had been mild and the patient had completely recovered in a few days. Results: At physical examination the patient presented with a slightly increased heart rate and a painful and enlarged thyroid on palpation. At laboratory exams free thyroxine and free triiodothyronine were high, thyrotropin undetectable, and inflammatory markers and white blood cell count elevated. Bilateral and diffuse hypoechoic areas were detected at neck ultrasound. One month earlier, thyroid function and imaging both were normal. We diagnosed SAT and the patient started prednisone. Neck pain and fever recovered within 2 days and the remaining symptoms within 1 week. Thyroid function and inflammatory markers normalized in 40 days. Conclusions: We report the first case of SAT after a SARS-CoV-2 infection. We alert clinicians to additional and unreported clinical manifestations associated with COVID-19
Point X-ray sources in the SNR G 315.4-2.30 (MSH 14-63, RCW 86)
We report the results of a search for a point X-ray source (stellar remnant)
in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63,
RCW 86) using the archival data of the Chandra X-ray Observatory. The search
was motivated by a hypothesis that G 315.4-2.30 is the result of an
off-centered cavity supernova explosion of a moving massive star, which ended
its evolution just near the edge of the main-sequence wind-driven bubble. This
hypothesis implies that the southwest protrusion in G 315.4-2.30 is the
remainder of a pre-existing bow shock-like structure created by the interaction
of the supernova progenitor's wind with the interstellar medium and that the
actual location of the supernova blast center is near the center of this
hemispherical structure. We have discovered two point X-ray sources in the
"proper" place. One of the sources has an optical counterpart with the
photographic magnitude , while the spectrum of the source can be
fitted with an optically thin plasma model. We interpret this source as a
foreground active star of late spectral type. The second source has no optical
counterpart to a limiting magnitude . The spectrum of this source can
be fitted almost equally well with several simple models (power law: photon
index ; two-temperature blackbody: keV, km and
keV, km; blackbody plus power law: keV,
photon index ). We interpret this source as a candidate stellar remnant
(neutron star), while the photon index and non-thermal luminosity of the source
(almost the same as those of the Vela pulsar and the recently discovered pulsar
PSR J 0205+6449 in the supernova remnant 3C 58) suggest that it can be a young
"ordinary" pulsar.Comment: 7 pages, 6 figures,revised version accepted for publication in A&
Reading a GEM with a VLSI pixel ASIC used as a direct charge collecting anode
In MicroPattern Gas Detectors (MPGD) when the pixel size is below 100 micron
and the number of pixels is large (above 1000) it is virtually impossible to
use the conventional PCB read-out approach to bring the signal charge from the
individual pixel to the external electronics chain. For this reason a custom
CMOS array of 2101 active pixels with 80 micron pitch, directly used as the
charge collecting anode of a GEM amplifying structure, has been developed and
built. Each charge collecting pad, hexagonally shaped, realized using the top
metal layer of a deep submicron VLSI technology is individually connected to a
full electronics chain (pre-amplifier, shaping-amplifier, sample and hold,
multiplexer) which is built immediately below it by using the remaining five
active layers. The GEM and the drift electrode window are assembled directly
over the chip so the ASIC itself becomes the pixelized anode of a MicroPattern
Gas Detector. With this approach, for the first time, gas detectors have
reached the level of integration and resolution typical of solid state pixel
detectors. Results from the first tests of this new read-out concept are
presented. An Astronomical X-Ray Polarimetry application is also discussed.Comment: 11 pages, 14 figures, presented at the Xth Vienna Conference on
Instrumentation (Vienna, February 16-21 2004). For a higher resolution paper
contact [email protected]
Sport, doping and male fertility
It is universally accepted that lifestyle interventions are the first step towards a good overall, reproductive and sexual health. Cessation of unhealthy habits, such as tobacco, alcohol and drug use, poor nutrition and sedentary behavior, is suggested in order to preserve/improve fertility in humans. However, the possible risks of physical exercise per se or sports on male fertility are less known. Being fit does not only improve the sense of well-being, but also has beneficial effects on general health: in fact physical exercise is by all means a low-cost, high-efficacy method for preventing or treating several conditions, ranging from purely physical (diabetes and obesity) to psychological (depression and anxiety), highly influencing male reproduction. If male sexual and reproductive health could be positively affected by a proper physical activity, inadequate bouts of strength - both excessive intensity and duration of exercise training - are more likely to have detrimental effects. In addition, the illicit use of prohibited drugs (i.e. doping) has reached pandemic proportions, and their actions, unfortunately very often underestimated by both amateur and professional athletes, are known to disrupt at different levels and throughout various mechanisms the male hypothalamic-pituitary-gonadal axis, resulting in hypogonadism and infertility
Is subacute thyroiditis an underestimated manifestation of SARS-CoV-2 infection? insights from a case series
Context: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 18 million people worldwide and the pandemic is still spreading. After the first case we reported, we observed 4 additional cases of subacute thyroiditis (SAT) related to SARS-CoV-2 infection. Objectives: The objective of this work is to describe additional cases of SAT associated with SARS-CoV-2 infection to alert physicians that SAT may be a manifestation of SARS-CoV-2 infection. Methods: We describe clinical, biochemical, and imaging features of 4 patients with SAT related to SARS-CoV-2 infection. Results: All patients were female (age, 29-46 years). SAT developed 16 to 36 days after the resolution of coronavirus disease 2019 (COVID-19). Neck pain radiated to the jaw and palpitations were the main presenting symptoms and were associated with fever and asthenia. One patient was hospitalized because of atrial fibrillation. Thyroid function tests (available for 3 individuals) were suggestive of destructive thyroiditis, and inflammatory markers were high. At neck ultrasound the thyroid was enlarged, with diffuse and bilateral hypoechoic areas and (in 3 patients) absent vascularization at color Doppler. Symptoms disappeared a few days after commencement of treatment (prednisone in 3 patients and ibuprofen in 1). Six weeks after the onset of SAT, all patients were asymptomatic and inflammatory markers had returned to normal range. Two patients were euthyroid, whereas 2 were diagnosed with subclinical hypothyroidism. Conclusions: SAT may be an underestimated manifestation of COVID-19. Clinicians should keep in mind the possible occurrence of SAT during and after SARS-CoV-2 infection
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