19,224 research outputs found
Fabrication of high temperature surface acoustic wave devices for sensor applications
Surface acoustic devices have been shown to be suitable not only for signal processing but also for sensor applications. In this paper high temperature surface acoustic wave devices based on gallium orthophosphate have been fabricated, using a lift-off technique and tested for high frequency applications at temperatures up to 600 ÂșC. The measured S-parameter (S11) has been used to study the mass loading effect of the platinum electrodes and turnover temperature of GaPO4 with a 5? cut. The analysis of these results shows that the mass loading effect can be used to predict the desired resonant frequency of the SAW devices. Also two different adhesion layers for Pt metallisation were studied. Our results show that Zirconium is a more suitable under layer than Titanium
Spontaneous Heterotrophic Pregnancy with Tubal Rupture and Delivery of a Live Baby at Term: a Case Report
Heterotopic pregnancy is the coexistence of intrauterine and extrauterine gestations. It is associated with significant maternal morbidity andmortality particularly in low resource settings. Spontaneous heterotopic pregnancy is very rarely seen with documented incidence of 1 in 30,000 pregnancies. We present the first case of heterotopic pregnancymanaged in our center with the delivery a live female baby at term.The case of a 25 year nulliparous lady who presented in our center with lower abdominal pains, amenorrhoea and an ultrasound report confirming an intrauterine pregnancy is presented. Examination revealed mild right iliac fossa tenderness, cervical motion tenderness and a bulky uterus. A trans-vaginal ultrasound scan confirmed a right fimbrial ectopic gestation. A right salpingectomy was performed. The patient subsequently had an uneventful antenatal period and spontaneous vaginal delivery of a live female baby at term. We also review literatures on heterotopicpregnancy and its management. Spontaneous heterotopic pregnancy, apotentially fatal condition though rare can occur in our environment. Clinicians should maintain a high index of suspicion in all patients presenting with amenorrhoea and abdominal pains even if an intrauterine pregnancy has been confirmed and a thorough evaluation of theadnexae using a trans-vaginal ultrasound scan should be routinely performed in such cases.Keywords: Spontaneous heterotopic pregnancy, live baby, Uy
Quantum Computing in Molecular Magnets
Shor and Grover demonstrated that a quantum computer can outperform any
classical computer in factoring numbers and in searching a database by
exploiting the parallelism of quantum mechanics. Whereas Shor's algorithm
requires both superposition and entanglement of a many-particle system, the
superposition of single-particle quantum states is sufficient for Grover's
algorithm. Recently, the latter has been successfully implemented using Rydberg
atoms. Here we propose an implementation of Grover's algorithm that uses
molecular magnets, which are solid-state systems with a large spin; their spin
eigenstates make them natural candidates for single-particle systems. We show
theoretically that molecular magnets can be used to build dense and efficient
memory devices based on the Grover algorithm. In particular, one single crystal
can serve as a storage unit of a dynamic random access memory device. Fast
electron spin resonance pulses can be used to decode and read out stored
numbers of up to 10^5, with access times as short as 10^{-10} seconds. We show
that our proposal should be feasible using the molecular magnets Fe8 and Mn12.Comment: 13 pages, 2 figures, PDF, version published in Nature, typos
correcte
The internal dynamics of privatised public education: Fee-charging supplementary tutoring provided by teachers in Cambodia
Much literature is available on private schools that operate alongside public schools, and on public schools that are encouraged to operate more like businesses in order to become more efficient and client-oriented. This paper, by contrast, focuses on privatisation by default behind a façade of fee-free education. It concerns supplementary private tutoring provided by government-employed teachers, in many cases to their own students in large classes and on the school premises. Drawing on questionnaire and interview data from secondary school students and teachers in one province of Cambodia, the paper examines interlinked factors that contribute to this process. These factors include low teachersâ salaries, lack of instructional time, large classes, and the possibility of different teacher-student relationships in supplementary lessons. The paper is contextualised within the wider literatures on privatisation and shadow education
The Contribution of Network Organization and Integration to the Development of Cognitive Control
Cognitive control, which continues to mature throughout adolescence, is supported by the ability for well-defined organized brain networks to flexibly integrate information. However, the development of intrinsic brain network organization and its relationship to observed improvements in cognitive control are not well understood. In the present study, we used resting state functional magnetic resonance imaging (RS-fMRI), graph theory, the antisaccade task, and rigorous head motion control to characterize and relate developmental changes in network organization, connectivity strength, and integration to inhibitory control development. Subjects were 192 10â26-y-olds who were imaged during 5 min of rest. In contrast to initial studies, our results indicate that network organization is stable throughout adolescence. However, cross-network integration, predominantly of the cingulo-opercular/salience network, increased with age. Importantly, this increased integration of the cingulo-opercular/salience network significantly moderated the robust effect of age on the latency to initiate a correct inhibitory control response. These results provide compelling evidence that the transition to adult-level inhibitory control is dependent upon the refinement and strengthening of integration between specialized networks. Our findings support a novel, two-stage model of neural development, in which networks stabilize prior to adolescence and subsequently increase their integration to support the cross-domain incorporation of information processing critical for mature cognitive control
INDICATION OF META-ANTHRACITE BY MAGNETOTELLURICS IN THE KĆSZEG-RECHNITZ PENNINIC WINDOW : A TEST AREA
One of the Penninic Nappes is the KĆszeg-Rechnitz (K-R) tectonic window at the Eastern end of the Eastern Alps. It has a complicated metamorphic history from the Jurassic time. The organic material of the Penninic Ocean was transformed to electrically conductive meta-anthracite. Its amount in the chalcophyllite is estimated by geochemists to 0.2 per cent.
Taking this conducting structure as a test area pilot deep magnetotelluric (MT) soundings have been carried out and we determined
- the structure of the conductivity anomaly due to 0.2 per cent meta anthracite in the K-R window and its surroundings
- the different kinds of MT distortions as lateral (side) effect of the conductor appearing in the crust and mantle
- the most probable depth of the conductive asthenosphere at the border of the Pannonian Basin (having extreme shallow asthenosphere). The obtained ~140 km depth is in correlation with value of the asthenospheric map based mainly on seismic data
Neuroendocrine morbidity after pediatric optic gliomas: a longitudinal analysis of 166 children over 30 years
Context: 50% of pediatric low-grade gliomas affect the optic pathway, hypothalamus and suprasellar
areas (OP/HSGs) resulting in significant long-term neuroendocrinopathy.
Objective: To dissect tumor- from treatment-related risk factors for OP/HSG-associated
neuroendocrinopathy.
Design: Retrospective case notes analysis of 166 children with newly-diagnosed OP/HSGs at our
quaternary center between 1980 â2010 by multivariate Cox, linear and logistic regression.
Results: Patients were of median (range) age 4.9 (0.2â15.4) years at diagnosis and followed up for
8.3 (0.04 â26.8) years. Despite high 20-year overall survival (81.0%), progression-free and endocrine
event-free (EEFS) survival were 47.2% and 20.8% respectively. EEFS declined up to 15 years postdiagnosis,
with hypothalamic involvement (p0.001) being implicated more than radiotherapy
(p0.008) in earlier endocrinopathy; the reverse being true of its density (radiotherapy p0.001;
hypothalamic involvement p0.006). GH deficiency (GHD) was commonest (40.3%), followed by
central precocious puberty (CPP, 26.0%), gonadotropin (GnD, 20.4%), TSH (13.3%), and ACTH
(13.3%) deficiencies. GHD increased with later treatment eras (p0.01), but replacement did not
increase progression. CPP was associated with future GnD (p0.05). Posterior pituitary dysfunction
(PPD, 7.2%) occurred in 57.9% after only biopsies or shunt procedures, and was associated with 6/13
deaths. 50.2% became obese. Tumor extent, surgery and increased endocrinopathy, rather than
radiotherapy, predicted visuo-cognitive morbidity.
Conclusions: This first longitudinal OP/HSG-specific study demonstrates that hypothalamo-pituitary
dysfunction evolves hierarchically over decades. Tumor location predicts its speed of onset and
radiotherapy its density. GnD can evolve from previous CPP, whilst life-threatening PPD can occur
after any surgery. Our data suggest that recent radiation-avoiding chemotherapeutic strategies
have increased GHD without improving survival
Reverse osmosis pretreatment method for toxicity assessment of domestic wastewater using Vibrio qinghaiensis sp.-Q67
Luminescent bacterial test is a fast and sensitive method for acute toxicity assessment of water and wastewater. In this study, an improved toxicity testing method was developed using the freshwater luminescent bacteria Vibrio qinghaiensis sp.-Q67 that involved pretreatment of water samples with reverse osmosis (RO) to eliminate the interferences caused by nutrients in concentrated samples and to improve the reliability and sensitivity of the analysis. Because water samples contain low concentrations of several target toxic substances, rapid acute toxicity testing method that is commonly employed does not achieve enough sensitivity. The proposed RO pretreatment could effectively enrich organic and inorganic substances in water samples to enable a more effective and sensitive toxicity evaluation. The kinetic characteristics of toxicity of raw sewage and secondary effluent were evaluated based on the relative luminescence unit (RLU) curves and time-concentration-effect surfaces. It was observed that when the exposure time was prolonged to 8-h or longer, the bacteria reached the logarithmic growth stage. Hence, the stimulating effects of the coexisting ions (such as Na+, K+, NO3-) in the concentrated samples could be well eliminated. A 10-h exposure time in proposed Q67 test was found to quantitatively evaluate the toxicity of the organic and inorganic pollutants in the RO-concentrated samples. © 2013 Elsevier Inc
Chiral zero-mode for abelian BPS dipoles
We present an exact normalisable zero-energy chiral fermion solution for
abelian BPS dipoles. For a single dipole, this solution is contained within the
high temperature limit of the SU(2) caloron with non-trivial holonomy.Comment: 9 pages, 1 figure (in 2 parts), presented at the workshop on
"Confinement, Topology, and other Non-Perturbative Aspects of QCD", 21-27
Jan. 2002, Stara Lesna, Slovaki
Decision-Making Competence and Attempted Suicide
Objective: The propensity of people vulnerable to suicide to make poor life decisions is increasingly well documented. Do they display an extreme degree of decision biases? The present study used a behavioral decision approach to examine the susceptibility of low-lethality and high-lethality suicide attempters to common decision biases, which may ultimately obscure alternative solutions and deterrents to suicide in a crisis. Method: We assessed older and middle-aged individuals who made high-lethality (medically serious; N=31) and low-lethality suicide attempts (N=29). Comparison groups included suicide ideators (N=30), non-suicidal depressed (N=53), and psychiatrically healthy participants (N=28). Attempters, ideators, and non-suicidal depressed participants had unipolar non-psychotic major depression. Decision biases included sunk cost (inability to abort an action for which costs are irrecoverable), framing (responding to superficial features of how a problem is presented), under/overconfidence (appropriateness of confidence in knowledge), and inconsistent risk perception. Data were collected between June of 2010 and February of 2014. Results: Both high- and low-lethality attempters were more susceptible to framing effects, as compared to the other groups included in this study (p< 0.05, ηp2 =.06). In contrast, low-lethality attempters were more susceptible to sunk costs than both the comparison groups and high-lethality attempters (p< 0.01, ηp2 =.09). These group differences remained after accounting for age, global cognitive performance, and impulsive traits. Premorbid IQ partially explained group differences in framing effects. Conclusion: Suicide attemptersâ failure to resist framing may reflect their inability to consider a decision from an objective standpoint in a crisis. Low-lethality attemptersâ failure to resist sunk cost may reflect their tendency to confuse past and future costs of their behavior, lowering their threshold for acting on suicidal thoughts
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