193 research outputs found
An In Vitro Intact Globe Expansion Method for Evaluation of Cross-linking Treatments
Purpose. To measure the tissue mechanical response to elevated
intraocular pressure (IOP) using intact globe expansion
of rabbit eyes. This method examined rabbit kit (2–3 weeks
old) eyes as a model for weakened tissue and evaluated riboflavin/
UVA and glyceraldehyde cross-linking treatments.
Methods. The ocular shape of enucleated eyes was photographed
during a 24-hour period while a controlled IOP was
imposed (either low IOP 22 mm Hg or high IOP 85 mm
Hg). Untreated controls consisted of kit eyes tested at both
low- and high IOP and adult eyes tested at high IOP. Treated kit
eyes (dextran controls, riboflavin/UVA treatment of the cornea,
and glyceraldehyde treatment of the entire globe) were tested
at high IOP.
Results. Low IOP elicited negligible creep of the sclera and
very gradual creep of the cornea. In contrast, high IOP induced
up to an 8% strain in the sclera and a 15% strain in the cornea
of rabbit kit eyes. The expansion of adult eyes was less than
one third that of kit eyes at the same, high IOP. Riboflavin/UVA
treatment of corneas reduced expansion compared with that in
both dextran-treated and untreated control corneas. Glyceraldehyde
treatment prevented expansion of the cornea and
sclera.
Conclusions. The intact globe expansion method (GEM) imposes
a loading geometry comparable to in vivo conditions and
can quantify changes in mechanical stability as a function of
testing conditions (e.g., IOP, tissue maturation, and therapeutic
cross-linking) with small sample sizes and small variability.
Rabbit kit eyes provide a model of weak tissue suitable for
screening treatments that strengthen the cornea and sclera
Micro-hovering air vehicle
When emergency situations arise, such as the events on 9/11,visual information needs to be gathered and assessed as quickly as possible so that rescue workers and emergency personnel can get the situation under control and save the lives of people in danger. Often in these situations human beings cannot safely obtain this information and have therefore typically relied on land based robots with wireless cameras to relay pertinent information. However these robots are limited by their inability to maneuver over large obstacles or climb up stairs. Our work consists of designing an aerial robot that can rise up and hover while transmitting streaming video to an operator who is controlling the height of its elevation. This robot will most likely consist of two counter-rotating propellers (to eliminate angular moment)
surrounded by a protective shroud (nacelle), outfitted with self-adjusting baffles under the airflow of the propellers. The shroud will protect both the robot and the environment (i.e. civilians, animal life) and will also house the wireless camera, power supply, and sensor suite used to control the baffles, which in turn maintain the stability of the craft. Important tasks include evaluating propeller motor combinations that best optimize our thrust to weight ratios, designing the nacelle, and programming the PIC 16F84 micro controller to adjust the anti-pitch baffles
Anxiety and its risk factors among non-Japanese residents living in Japan undergoing COVID-19 situation: A cross-sectional survey
Introduction In the context of collective efforts taken in Japan to control the spread of COVID-19, the state of emergency and social distancing have caused a negative impact on the mental health of all residents, including foreign communities in Japan. This study aimed to evaluate the level of anxiety and its associated factors among non-Japanese residents residing in Japan during the COVID-19 pandemic. Methods A web-based survey in 13 languages was conducted among non-Japanese residents living in Japan during the COVID-19 situation. The State-Trait Anxiety Inventory assessed the level of anxiety–State (STAI-S) scores prorated from its six-item version. The multivariable logistic regression using the Akaike Information Criterion (AIC) method was performed to identify the associated factors of anxiety among participants. Results From January to March 2021, we collected 392 responses. A total of 357 valid responses were analyzed. 54.6% of participants suffered from clinically significant anxiety (CSA). In multivariable logistic model analysis, the CSA status or the high level of anxiety was associated with three factors, including having troubles/difficulties in learning or working, decreased sleep duration, and decreased overall physical health (p<0.05). Conclusion Our study suggests several possible risk factors of anxiety among non-Japanese residents living in Japan undergoing the COVID-19 pandemic, including the troubles or difficulties in learning or working, the decrease in sleep duration, and the decrease in overall physical health.Revisión por pare
Profiles of Parental Burnout Around the Globe: Similarities and Differences Across 36 Countries
Parental burnout (PB) is a pervasive phenomenon. Parenting is embedded in cultural values, and previous research has shown the role of individualism in PB. In this paper, we reanalyze previously collected data to identify profiles based on the four dimensions of PB, and explore whether these profiles vary across countries’ levels of collectivistic-individualistic (COL-IND) values. Our sample comprised 16,885 individuals from 36 countries (73% women; 27% men), and we used a latent profile approach to uncover PB profiles. The findings showed five profiles: Fulfilled, Not in PB, Low risk of PB, High risk of PB and Burned out. The profiles pointed to climbing levels of PB in the total sample and in each of the three country groups (High COL/Low IND, Medium COL-IND, Low COL/High IND). Exploratory analyses revealed that distinct dimensions of PB had the most prominent roles in the climbing pattern, depending on the countries’ levels of COL/IND. In particular, we found contrast to be a hallmark dimension and an indicator of severe burnout for individualistic countries. Contrary to our predictions, emotional distance and saturation did not allow a clear differentiation across collectivistic countries. Our findings support several research avenues regarding PB measurement and intervention
Genome-wide analysis identifies 12 loci influencing human reproductive behavior.
The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
The role of ETG modes in JET-ILW pedestals with varying levels of power and fuelling
We present the results of GENE gyrokinetic calculations based on a series of JET-ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels of power and gas fuelling. We show that turbulence due to electron-temperature-gradient (ETGs) modes produces a significant amount of heat flux in four JET-ILW discharges, and, when combined with neoclassical simulations, is able to reproduce the experimental heat flux for the two low gas pulses. The simulations plausibly reproduce the high-gas heat fluxes as well, although power balance analysis is complicated by short ELM cycles. By independently varying the normalised temperature gradients (omega(T)(e)) and normalised density gradients (omega(ne )) around their experimental values, we demonstrate that it is the ratio of these two quantities eta(e) = omega(Te)/omega(ne) that determines the location of the peak in the ETG growth rate and heat flux spectra. The heat flux increases rapidly as eta(e) increases above the experimental point, suggesting that ETGs limit the temperature gradient in these pulses. When quantities are normalised using the minor radius, only increases in omega(Te) produce appreciable increases in the ETG growth rates, as well as the largest increases in turbulent heat flux which follow scalings similar to that of critical balance theory. However, when the heat flux is normalised to the electron gyro-Bohm heat flux using the temperature gradient scale length L-Te, it follows a linear trend in correspondence with previous work by different authors
Spectroscopic camera analysis of the roles of molecularly assisted reaction chains during detachment in JET L-mode plasmas
The roles of the molecularly assisted ionization (MAI), recombination (MAR) and dissociation (MAD) reaction chains with respect to the purely atomic ionization and recombination processes were studied experimentally during detachment in low-confinement mode (L-mode) plasmas in JET with the help of experimentally inferred divertor plasma and neutral conditions, extracted previously from filtered camera observations of deuterium Balmer emission, and the reaction coefficients provided by the ADAS, AMJUEL and H2VIBR atomic and molecular databases. The direct contribution of MAI and MAR in the outer divertor particle balance was found to be inferior to the electron-atom ionization (EAI) and electron-ion recombination (EIR). Near the outer strike point, a strong atom source due to the D+2-driven MAD was, however, observed to correlate with the onset of detachment at outer strike point temperatures of Te,osp = 0.9-2.0 eV via increased plasma-neutral interactions before the increasing dominance of EIR at Te,osp < 0.9 eV, followed by increasing degree of detachment. The analysis was supported by predictions from EDGE2D-EIRENE simulations which were in qualitative agreement with the experimental observations
Shattered pellet injection experiments at JET in support of the ITER disruption mitigation system design
A series of experiments have been executed at JET to assess the efficacy of the newly installed shattered pellet injection (SPI) system in mitigating the effects of disruptions. Issues, important for the ITER disruption mitigation system, such as thermal load mitigation, avoidance of runaway electron (RE) formation, radiation asymmetries during thermal quench mitigation, electromagnetic load control and RE energy dissipation have been addressed over a large parameter range. The efficiency of the mitigation has been examined for the various SPI injection strategies. The paper summarises the results from these JET SPI experiments and discusses their implications for the ITER disruption mitigation scheme
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