907 research outputs found
Implementation of Fault-tolerant Quantum Logic Gates via Optimal Control
The implementation of fault-tolerant quantum gates on encoded logic qubits is
considered. It is shown that transversal implementation of logic gates based on
simple geometric control ideas is problematic for realistic physical systems
suffering from imperfections such as qubit inhomogeneity or uncontrollable
interactions between qubits. However, this problem can be overcome by
formulating the task as an optimal control problem and designing efficient
algorithms to solve it. In particular, we can find solutions that implement all
of the elementary logic gates in a fixed amount of time with limited control
resources for the five-qubit stabilizer code. Most importantly, logic gates
that are extremely difficult to implement using conventional techniques even
for ideal systems, such as the T-gate for the five-qubit stabilizer code, do
not appear to pose a problem for optimal control.Comment: 18 pages, ioptex, many figure
Chemical-assisted physico-biological water mining system
Water mining is the process of extracting valuable water from a sewerage network by treating raw sewage to high standards. A range of commercially viable water mining treatment technologies are now available to treat sewage to specified water quality targets. Most of these technologies have minimal plant footprint requirements, making them suitable for decentralised operations. This paper discusses a hybrid water mining system that includes chemically assisted fine solids separation followed by a biological treatment process. Results from the first proof testing of this water mining system in Sydney, Australia are presented. The results confirm the suitability of the hybrid system for producing high-quality water for non-potable reuse
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Readout electronics for a High-Rate CSC detector
A readout system for a high-rate muon Cathode Strip Chamber (CSC) is described. The system, planned for use in the forward region of the ATLAS muon spectrometer, uses two custom CMOS integrated circuits to achieve good position resolution at a flux of up to 2,500 tracks/cm{sup 2}/s
The clinical and phenotypical assessment of seronegative villous atrophy; a prospective UK centre experience evaluating 200 adult cases over a 15-year period (2000-2015).
BACKGROUND: Seronegative villous atrophy (SNVA) is commonly attributed to coeliac disease (CD). However, there are other causes of SNVA. More recently angiotensin-2-receptor-blockers (A2RBs) have been reported as an association but data on SNVA have been limited to centres evaluating complex case referrals and not SNVA in general. OBJECTIVES: To provide clinical outcomes and associations in a large prospective study overseeing all newcomers with SNVA. DESIGN: Over a 15-year period (2000-2015) we evaluated 200 adult patients with SNVA at a UK centre. A diagnosis of either seronegative CD (SNCD) or seronegative non-CD (SN-non-CD) was reached. Baseline comparisons were made between the groups, with 343 seropositive CD subjects serving as controls. RESULTS: Of the 200 SNVA cases, SNCD represented 31% (n=62) and SN-non-CD 69% (n=138). The human leucocyte antigen (HLA)-DQ2 and/or DQ8 genotype was present in 61%, with a 51% positive predictive value for SNCD. The breakdown of identifiable causes in the SN-non-CD group comprised infections (27%, n=54), inflammatory/immune-mediated disorders (17.5%, n=35) and drugs (6.5%, n=13; two cases related to A2RBs). However, no cause was found in 18% (n=36) and of these 72% (n=26/36) spontaneously normalised duodenal histology while consuming a gluten-enriched diet. Following multivariable logistic regression analysis an independent factor associated with SN-non-CD was non-white ethnicity (OR 10.8, 95% CI 2.2 to 52.8); in fact, 66% of non-whites had GI infections. On immunohistochemistry all groups stained positive for CD8-T-cytotoxic intraepithelial lymphocytes. However, additional CD4-T helper intraepithelial lymphocytes were occasionally seen in SN-non-CD mimicking the changes associated with refractory CD. CONCLUSIONS: Most patients with SNVA do not have CD, in particular those who are not white. Furthermore, a subgroup with no obvious aetiology will show spontaneous histological resolution while consuming gluten. These findings suggest caution in empirically prescribing a gluten-free diet without investigation
SOME ABSTRACT PROPERTIES OF SEMIGROUPS APPEARING IN SUPERCONFORMAL THEORIES
A new type of semigroups which appears while dealing with
superconformal symmetry in superstring theories is considered. The ideal series
having unusual abstract properties is constructed. Various idealisers are
introduced and studied. The ideal quasicharacter is defined. Green's relations
are found and their connection with the ideal quasicharacter is established.Comment: 11 page
A comparative study of spontaneously conceived twin pregnancies vs. twins conceived by assisted reproductive techniques and their maternal and perinatal outcomes: a prospective observational study
Background: The utilization of assisted reproductive techniques has led to a notable increase in the incidence of twin pregnancies. Neonates from multifetal gestations also make up a disproportionate percentage of very-low-birthweight newborns and have increased risks of having congenital malformations and preterm birth. This study was done to compare the maternal and and perinatal outcomes of spontaneously conceived twins and those twins conceived by assisted reproductive techniques.
Methods: The present hospital based observational study was done at Chettinad Hospital and Research Institute, Chennai, India over a period of 36 months between February 2021 to January 2024 among pregnant women with twin gestation attending the outpatient department during the study period. 50 antenatal mothers with twin pregnancy and 50 pairs of twins were studied. Convenient sampling technique was adopted. The subjects were followed up from the booking visit, till the postpartum discharge day. Any adverse maternal, foetal, neonatal outcomes and the treatment given were studied.
Results: The mean birth weight among those with spontaneous conception and assisted reproductive techniques conception was 2.23±0.46 kgs and 2.02±0.51 kgs, respectively. Both the groups were similar with regard to the birth weight. 6.6% babies from the spontaneous conception group and 5% from the assisted reproductive techniques conception group were admitted for respiratory distress and rest from both the groups got admitted for sepsis. The mean duration of hospital stay was 3.58±2.40 days for the spontaneous conception group and 3.75±2.71 days for assisted reproductive techniques conception.
Conclusions: This study concludes that the maternal and fetal outcomes of twin deliveries conceived spontaneously or through assisted reproductive techniques do not differ significantly in their outcome
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