770 research outputs found
Toric anti-self-dual 4-manifolds via complex geometry
Using the twistor correspondence, this article gives a one-to-one
correspondence between germs of toric anti-self-dual conformal classes and
certain holomorphic data determined by the induced action on twistor space.
Recovering the metric from the holomorphic data leads to the classical problem
of prescribing the Cech coboundary of 0-cochains on an elliptic curve covered
by two annuli. The classes admitting Kahler representatives are described; each
such class contains a circle of Kahler metrics. This gives new local examples
of scalar-flat Kahler surfaces and generalises work of Joyce who considered the
case where the distribution orthogonal to the torus action is integrable.Comment: 25 pages, 2 figures, v2 corrected some misprints, v3 corrected more
misprints, published version (minus one typo
Prevalence of Malaria Parasites among Pregnant Women and Children under Five years in Ekiti State, Southwest Nigeria.
Background: Malaria is a deadly disease causing serious public health issues among pregnant women and children worldwide especially in tropical and subtropical Africa. This study was carried out to determine the prevalence of malaria parasites among pregnant women and children under five years in Ekiti State, Nigeria.Methodology: A total of 380 blood samples were collected from the pregnant women and children under five years respectively. Malaria parasites were examined microscopically on thick and thin blood smear stained with Giemsa stain while personal data were collected through questionnaire and confirmed from file records. Red cell phenotyping was carried out manually with standard tube technique for blood group. Haemoglobin electrophoresis was carried out using the cellulose acetate alkaline haemoglobin electrophoresis technique, which allowed for the separation of haemoglobin A, F, S, and C into distinct bands.Results: The results showed that of 380 pregnant women sampled, 153 (40.2%) were positive for malaria parasites and 63 (63%) were positive of the 100 children sampled. The highest prevalence of malaria parasites 18 (51.4%) and 25 (71.4%) were observed in ages 36-39 and <1 years for pregnant women and children respectively. Multigravidae was 1.19 times (95% Cl: 0.77, 1.84) more vulnerable to malaria compare to primigravidae. Women in the first trimester were more infected with malaria parasites 40 (75.4%) than those in second trimester 46 (23.3%) and third trimester 67 (51.9%). Among children under five years of age, females 38 (66.7%) had the highest prevalence compared to males 25 (58.1%). However, there was no significant difference. Statistical analysis showed a significant difference in genotype types (P<0.05).Conclusion: This study revealed that malaria infection is still endemic in the study area, hence, there is urgent need to deploy management strategy to the study area
Investigation into Effect of Cooling Rate on Magnetic Properties of Alloys that Are Based on FeCoB Matrix
Change of Magnetic Saturation Polarisation as a Function of Temperature in Bulk Fe-Based Amorphous Alloys
Optimal realization of the transposition maps
We solve the problem of achieving the optimal physical approximation of the
transposition for pure states of arbitrary quantum systems for finite and
infinite dimensions. A unitary realization is also given for any finite
dimension, which provides the optimal quantum cloning map of the ancilla as
well.Comment: 10 pages. No figures. Elsart styl
Wolbachia pipientis: first detection in populations of Glycaspis brimblecombei (Hemiptera: Aphalaridae) and Psyllaephagus bliteus (Hymenoptera: Encyrtidae) in Brazil
The sucking insect, Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae), is originally from Australia and reduces the productivity of Eucalyptus crops. The parasitoid Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is the main agent used in the integrated management of G. brimblecombei. Endosymbionts, in insects, are important in the adaptation and protection of their hosts to the environment. The intracellular symbionts Wolbachia, induces reproductive changes such as cytoplasmic incompatibility, feminization, male death and parthenogenesis. The objective of this study was to report the first record of Wolbachia pipientis in populations of G. brimblecombei and of its parasitoid P. bliteus in the field in Brazil. Branches with adults of G. brimblecombei and P. bliteus were collected from eucalyptus trees in commercial farms in six Brazilian states and, after emergence, the insects obtained were frozen at -20 °C. Polymerase chain reaction (PCR) was performed to detect the Wolbachia endosymbiont.
Wolbachia pipientis was identified in individuals of G. brimblecombei and its parasitoid P. bliteus from populations of the counties of Agudos and Mogi-Guaçu (São Paulo State), Itamarandiba (Minas Gerais State) and São Jerônimo da Serra (Paraná State) in Brazi
Comparing responsiveness of the EQ-5D-5L, EQ-5D-3L and EQ VAS in stroke patients
Aims: To date, evidence to support the construct validity of the EQ-5D-5L has primarily focused on cross-sectional data. The aims of this study were to examine the responsiveness of EQ-5D-5L in patients with stroke and to compare it with responsiveness of EQ-5D-3L and visual analogue scale (EQ VAS). Methods: We performed an observational longitudinal cohort study of patients with stroke. At 1 week and 4 months post-stroke, patients were assessed with modified Rankin Scale (mRS) and Barthel Index (BI) and were administered the EQ-5D-5L and EQ-5D-3L, including the EQ VAS. The EQ-5D-5L index scores were derived using the crosswalk methodology developed by the EuroQol Group. We classified patients according to two external criteria, based on mRS or BI, into 3 categories: ‘improvement,’ ‘stable’ or ‘deterioration’. We assessed the responsiveness of each measure in each patient subgroup using: effect size (ES), standardized response mean (SRM), F-statistic, relative efficiency and area under the receiver operating characteristic curve. Results: A total of 112 patients (52 % females; mean age 70.6 years; 93 % ischemic stroke) completed all the instruments at both occasions. In subjects with clinical improvement, EQ-5D-5L was consistently responsive, showing moderate ES (0.51–0.71) and moderate to large SRM (0.69–0.86). In general, EQ-5D-3L index appeared to be more responsive (ES 0.63–0.82; SRM 0.77–1.06) and EQ VAS less responsive (ES 0.51–0.65; SRM 0.59–0.69) than EQ-5D-5L index. Conclusions: The EQ-5D-5L index, based on the crosswalk value set, seems to be appropriately responsive in patients with stroke, 4 months after disease onset. As far as EQ-5D-5L index is scored according to crosswalk approach, the EQ-5D-3L index appears to be more responsive in stroke population
Morse theory of the moment map for representations of quivers
The results of this paper concern the Morse theory of the norm-square of the
moment map on the space of representations of a quiver. We show that the
gradient flow of this function converges, and that the Morse stratification
induced by the gradient flow co-incides with the Harder-Narasimhan
stratification from algebraic geometry. Moreover, the limit of the gradient
flow is isomorphic to the graded object of the
Harder-Narasimhan-Jordan-H\"older filtration associated to the initial
conditions for the flow. With a view towards applications to Nakajima quiver
varieties we construct explicit local co-ordinates around the Morse strata and
(under a technical hypothesis on the stability parameter) describe the negative
normal space to the critical sets. Finally, we observe that the usual Kirwan
surjectivity theorems in rational cohomology and integral K-theory carry over
to this non-compact setting, and that these theorems generalize to certain
equivariant contexts.Comment: 48 pages, small revisions from previous version based on referee's
comments. To appear in Geometriae Dedicat
Nucleon Charge and Magnetization Densities from Sachs Form Factors
Relativistic prescriptions relating Sachs form factors to nucleon charge and
magnetization densities are used to fit recent data for both the proton and the
neutron. The analysis uses expansions in complete radial bases to minimize
model dependence and to estimate the uncertainties in radial densities due to
limitation of the range of momentum transfer. We find that the charge
distribution for the proton is significantly broad than its magnetization
density and that the magnetization density is slightly broader for the neutron
than the proton. The neutron charge form factor is consistent with the Galster
parametrization over the available range of Q^2, but relativistic inversion
produces a softer radial density. Discrete ambiguities in the inversion method
are analyzed in detail. The method of Mitra and Kumari ensures compatibility
with pQCD and is most useful for extrapolating form factors to large Q^2.Comment: To appear in Phys. Rev. C. Two new figures and accompanying text have
been added and several discussions have been clarified with no significant
changes to the conclusions. Now contains 47 pages including 21 figures and 2
table
Application of molecular cytogenetic techniques to clarify apparently balanced complex chromosomal rearrangements in two patients with an abnormal phenotype: Case report
Background. Complex chromosomal rearrangements (CCR) are rare cytogenetic findings that are difficult to karyotype by conventional cytogenetic analysis partially because of the relative low resolution of this technique. High resolution genotyping is necessary in order to identify cryptic imbalances, for instance near the multiple breakpoints, to explain the abnormal phenotype in these patients. We applied several molecular techniques to elucidate the complexity of the CCRs of two adult patients with abnormal phenotypes. Results. Multicolour fluorescence in situ hybridization (M-FISH) showed that in patient 1 the chromosomes 1, 10, 15 and 18 were involved in the rearrangement whereas for patient 2 the chromosomes 5, 9, 11 and 13 were involved. A 250 k Nsp1 SNP-array analysis uncovered a deletion in chromosome region 10p13 for patient 1, harbouring 17 genes, while patient 2 showed no pathogenic gains or losses. Additional FISH analysis with locus specific BAC-probes was performed, leading to the identification of cryptic interstitial structural rearrangements in both patients. Conclusion. Application of M-FISH and SNP-array analysis to apparently balanced CCRs is useful to delineate the complex chromosomal rearrangement in detail. However, it does not always identify cryptic imbalances as an explanation for the abnormal phenotype in patients with a CCR
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