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OBJECTIVES/SPECIFIC AIMS: Cesarean delivery is typically performed in the extremely preterm period (23 to 28 weeks) when the fetus is in breech presentation to avoid the potential risk of head entrapment by an insufficiently dilated cervix during a vaginal delivery. Assessment of the prevalence of extremely preterm breech cesarean delivery would help to appropriately guide future clinical interventions designed to increase the feasibility of vaginal delivery for this sub-group of patients. METHODS/STUDY POPULATION: We performed a cross-sectional study of the 2106 U.S. National Vital Statistics birth certificate database to estimate the prevalence of cesarean deliveries performed during the period of gestation from 23 to 28 weeks with a fetus in breech presentation. RESULTS/ANTICIPATED RESULTS: An analysis of the total births in the 2016 registry (3,945,875) was performed. The gestational age was limited to the target range of 23 0/7 to 27 6/7 weeks. Multiple gestation deliveries were excluded. This yielded 16,092 births of which 4,849 were noted to have breech presentation. The proportion of cesarean deliveries performed for singleton breech fetuses at this gestational range was 87% (4,203/4,849). DISCUSSION/SIGNIFICANCE OF IMPACT: The probability of undergoing a cesarean delivery for an extremely preterm fetus in breech presentation is notably higher (87%) when compared to an overall cesarean delivery rate of 31.9%. Specific interventions to allow for vaginal delivery in this particular sub-group of the obstetric population would be useful to reduce maternal morbidity by increasing vaginal deliveries. Future work will attempt to address innovative solutions to prevent head entrapment by the cervix in this particular population and ultimately avoid cesarean delivery.
The Scylla plasma which is contained in a ceramic discharge tube has been purposely contaminated with known impurities. The spectrum of the discharge with Fe (CO)5 added shows most of the solar lines in the 150–220 Å region. Some of these strong lines may be produced by iron in intermediate stages of ionization (Fe X to Fe XIV).
The scattering of radiation in the presence of weak magnetic fields can give rise to coherence or interference phenomena that will profoundly affect the frequency, geometric, and polarization properties of the scattering event. In this paper we discuss and illustrate some of the features of the coherence phenomena associated with the scattering redistribution for the normal Zeeman triplet. The frequency dependent as well as the frequency independent scattering function is considered in a linear polarization basis. In addition we illustrate some properties of this redistribution function in the Stokes representation. Since the primary purpose of this paper is to demonstrate the nature of some of the properties of the coherence problems, that might be important in the interpretation of magnetic fields from polarization measurements of scattered radiation, it has been necessary in this initial work to neglect several features of the problem which are noted in the paper and are currently under investigation.
Petrous apex cholesterol granulomas are expansile, cystic lesions containing cholesterol crystals surrounded by foreign body giant cells, fibrous tissue reaction and chronic inflammation. Appropriate treatment relies on an accurate radiological diagnosis and an understanding of the distinguishing radiological features of relevant entities in the differential diagnosis of this condition.
Firstly, this paper presents a pictorial review of the relevant radiological features of petrous apex cholesterol granuloma, and highlights unique features relevant to the differential diagnosis. Secondly, it reviews the histopathological and radiological findings associated with surgical drainage of these lesions.
Radiological features relevant to the differential diagnosis of petrous apex cholesterol granuloma are reviewed, together with radiological and histopathological features relevant to surgical management. Following surgical management, histopathological and radiological evidence demonstrates that the patency of the surgical drainage pathway is maintained.
Accurate diagnosis of petrous apex cholesterol granuloma is essential in order to instigate appropriate treatment. Placement of a stent in the drainage pathway may help to maintain patency and decrease the likelihood of symptomatic recurrence.
ZnSe/GaAs heterojunctions were investigated by contactless electroreflectance and photoreflectance techniques. Negative surface charge densities on the order of 1012 cm-2 were observed for films grown on n-type GaAs indicating a large contribution to the conduction band barrier between the materials due to band bending. The conduction band offset was also measured using a new photoreflectance technique involving a tunable pump laser.
High quality ZnSe:Cl has been grown on GaAs by gas source molecular beam epitaxy (GSMBE); elemental Zn and H2Se are used as source materials, with ZnCl2 as a dopant source for donors. Atomic Cl concentrations ([Cl]) approaching 1020 cm−3 have been incorporated into the lattice as indicated by secondary ion mass spectrometry (SIMS). At incorporation levels greater than 1020 cm−3, an appreciable decrease in the growth rate has been observed. The sharp transition to a negligible growth rate is attributed to the occurrence of a surface chemical reaction originating from Cl and H which are present in the GSMBE environment. For [Cl] as high as 4 x 1018 cm−3, the films exhibited high crystalline quality, as indicated by photoluminescence originating from a single intense donor-bound excitonic transition. Hydrogenation of semiconductors can potentially result in the electrical passivation of incorporated acceptor and donor species. In the case of ZnSe:Cl, H was present in the ZnSe layers, but did not appear to adversely affect the electrical properties of the n-type films. In contrast, for the growth of ZnSe:N, where a nitrogen plasma cell was employed as a source of nitrogen, the H concentration (as determined by SIMS) was observed to track the N concentration. The ZnSe:N films were highly resistive for various amounts of N incorporation, which suggests that H incorporation is an issue of primary importance in the p-type doping of ZnSe grown by GSMBE.
Recently, advanced photonic devices have been fabricated in the laboratory
and are becoming commercially available. Thus, there is considerable
interest in inexpensive but efficient non-linear optical (NLO) materials
that are simple to make and work with. In the last three years a large
number of publications and patents have appeared describing NLO properties
of organic materials, usually dyes, incorporated into or synthetically
attached to polymers . Such materials must be oriented before they have
second-order NLO activity. Two methods have been used. In one, contact
poling [2–5], two electrodes are formed on or in the material and an
electric field is placed between them. In the other, corona poling, a
discharge deposits charge on the polymer, which creates a strong orienting
field [6–8]. One could generalize that contact poling is (more) difficult to
do, but the results are easy to understand, while corona poling is simple to
do, but the results are (more) difficult to understand. This paper describes
a set of corona poling experiments.
The Honduran Emerald Amazilia luciae is endemic to dry forests of Honduras and currently recognised as ‘Critically Endangered.’ Here we present the first modern assessment of its distribution, ecology, and conservation, based partly on our rediscovery of the species in western Honduras and on our observations in three Honduran departments. We found that dry forests inhabited by the emerald differed in structure and species composition between eastern and western Honduras, where we observed emeralds in open-canopied deciduous thorn forests and closed-canopied semi-deciduous woodlands, respectively. We interpret these differences in light of the geological and anthropogenic origins of dry forests in Honduras, and discuss the implications of such origins for the conservation of dry forests. Although our findings expand the known distribution and population size of the species, its status as ‘Critically Endangered’ is warranted due to its restricted distribution in dry forest fragments and increasing human pressures on this habitat.
To date, fully cosmological hydrodynamic disk simulations to redshift zero have only been undertaken with particle-based codes, such as GADGET, Gasoline, or GCD+. In light of the (supposed) limitations of traditional implementations of smoothed particle hydrodynamics (SPH), or at the very least, their respective idiosyncrasies, it is important to explore complementary approaches to the SPH paradigm to galaxy formation. We present the first high-resolution cosmological disk simulations to redshift zero using an adaptive mesh refinement (AMR)-based hydrodynamical code, in this case, RAMSES. We analyse the temporal and spatial evolution of the simulated stellar disks' vertical heating, velocity ellipsoids, stellar populations, vertical and radial abundance gradients (gas and stars), assembly/infall histories, warps/lopsideness, disk edges/truncations (gas and stars), ISM physics implementations, and compare and contrast these properties with our sample of cosmological SPH disks, generated with GCD+. These preliminary results are the first in our long-term Galactic Archaeology Simulation program.
We present model-based inference for proteomic peak identification and quantification from mass spectroscopy data, focusing on nonparametric Bayesian models. Using experimental data generated from MALDI-TOF mass spectroscopy (matrix-assisted laser desorption ionization time-of-flight) we model observed intensities in spectra with a hierarchical nonparametric model for expected intensity as a function of time-of-flight. We express the unknown intensity function as a sum of kernel functions, a natural choice of basis functions for modeling spectral peaks. We discuss how to place prior distributions on the unknown functions using Lévy random fields and describe posterior inference via a reversible jump Markov chain Monte Carlo algorithm.
The advent of matrix-assisted laser desorption/ionization such time-of-flight (MALDI-TOF) mass spectroscopy and related SELDI-TOF (surface enhanced laser desorption/ionization) allows the simultaneous assay of thousands of proteins, and has transformed research in protein regulation underlying complex physiological processes. This technology provides the means to detect large proteins in a range of biological samples, from serum and urine to complex tissues, such as tumors and muscle. With appropriate statistical analysis, one may explore patterns of protein expression on a large scale in high-throughput studies without the need for prior knowledge of which proteins may be present (Baldwin et al., 2001; Diamandis, 2003; Martin and Nelson, 2001; Petricoin and Liotta, 2003; Petricoin et al., 2002). As such, it becomes a discovery tool, identifying proteins and pathways that are linked to a biological process. In applications, tens to thousands of spectra may be collected, leading to massive volumes of data. Each spectrum contains on the order of tens of thousands of intensity measurements, with an unknown number of peaks representing proteins of specific mass-to-charge ratios.
The Department of Health has emphasised the need for a patient-centred National Health Service (NHS), and the involvement of users and carers in mental health services is often a policy recommendation (Mental Health Task Force User Group, 1995; NHS Health Advisory Service, 1997; Department of Health, 1999a,b, 2001). The Patients' Forum and Consumers in NHS Research are established national bodies concerned with stakeholder involvement. The Commission for Patient and Public Involvement in Health was established in 2003.
Host-plant resistance plays an important role in the insect-pest management either alone or in combination with other control methods. A number of sorghum genotypes showing varying levels of resistance to spotted stem borer, Chilo partellus Swinhoe have been identified using natural and artificial infestations. Major resistance mechanisms are antibiosis and tolerance, though some genotypes exhibit ovipositional non-preferences. There have been a number of factors involved in spotted stem borer resistance; a resistant genotype possesses either one or a combination of these traits. Progress has been made in developing borer resistant breeding lines with moderate yield and acceptable grain quality. Borer resistance is a quantitatively inherited trait governed by additive and non-additive genes. Epistatic gene effects are more pronounced under artificial borer infestation. Cytoplasmic effects appear to be present.
Genetic diversity analysis was conducted on a set of 20 sorghum [Sorghum bicolor (L.) Moench] cultivars having resistance to shootfly (Atherigona seccata Rond.), originating from different geographic regions, and representing different taxonomic groups. The genetic diversity for shootfly resistance was assessed using multivariate analysis (D2 statistic and canonical variate analysis), and geographic/taxonomic divergence. The grouping of cultivars based on genetic divergence was found more accurate and relevant than that based on either geographic or taxonomie divergence. Both D2 and canonical variate analyses gave very similiar clustering patterns over the years analysed. Trichome density contributed mainly toward genetic divergence in shootfly resistance, followed by glossiness. Based on the presence or absence of these traits, the cultivars resistant to shootfly were classified into four major clusters. Resistant cultivars IS 844 and IS 1054 formed separate clusters over the years. Heterosis for shootfly resistance was found associated with genetic divergence but not with geographic or taxonomie divergence.
Inheritance of resistance to sorghum midge, Contarinia sorghicola Coq. was studied on a set of 21 diallel crosses involving four midge-resistant and three susceptible sorghum, Sorghum bicolor (L.) Moench cultivars under natural midge infestation at Dharwad during the late rainy season (August to November) 1983. Both additive and nonadditive genetic variances were important for midge resistance. The parents, DJ 6514 and TAM 2566, proved as better general combiners. Mean performance of the parents and their general combining ability (GCA) effects were strongly correlated. Crosses with positive specific combining ability (SCA) effects in both F1 and F2 generations had at least one parent with high GCA effects and better per se midge resistance. Midge-resistant parents, DJ 6514 and TAM 2566, with high per se resistance and GCA effects should be utilized in breeding for midge resistance.
In India, sorghum is grown during the post-rainy season on Vertisols with stored soil moisture. As water stress towards the end of the growing season is believed to be a major cause of poor yields in these crops, an experiment was carried out involving five sorghum genotypes and four sowing dates with and without irrigation.
Supplementary irrigation with 40 mm of water in the earliest sown crop increased grain yields by 24 and 26% in 1979 and 1982, respectively, while irrigation with a total of 120mm water in the latest sown crop increased yields by 87 and 60% compared with the corresponding dryland crops. Early sowings always resulted in better stover and grain yields irrespective of irrigation treatment. Grain yields of hybrids were similar to those of the cultivars but their stover yields were less. The post-rainy season cultivar SPY 86 gave the best grain yield across sowing dates. The widely grown post-rainy season cultivar M 35–1 yielded less but produced more stover and its yields were more stable. The importance of the stability of grain and stover yields and of evaluating the materials for more than one date of sowing in selecting sorghums for the post-rainy season is discussed.
Two artificial diets — one liquid, the other candied — developed for adult Itoplectis conquisitor, an ichneumonid parasitoid, proved equal in performance for fecundity to a natural food regimen involving blood of host pupa, Galleria mellonella. Feeding on the liquid diet resulted in a parasitoid emergence rate from host pupae of 42.9 ± 8.6%; on the candy diet, 52.2 ± 15.8%; and on the natural regimen, 54.4 ± 4.0%. Therefore, host material was not needed to feed the adults. Other advantages of these artificial diets include convenience, economy, efficacy, and manageability for proper insect husbandry.
This note reports the first in vitro oviposition and rearing of a parasitic insect, the endoparasitoid wasp Itoplectis conquisitor (Say), a male, on an artificial host consisting of an encapsulated synthetic, or meridic (Dougherty 1959, p. 53), medium.
Parasitic insects, of course, have been reared in vitro on meridic diets (House 1954; Yazgan 1972; Thompson 1975). Some were reported to oviposit into artificial objects (Arthur et al. 1972; Rajendram and Hagen 1974; Hoffman et al. 1975). Trichogramma pretiosum Riley laid viable eggs and development to adults occurred in small wax-resin spheres filled with host haemolymph (Hoffman et al. 1975).
Differences were shown in the rate of larval development of the fly Agria housei Shewell reared axenically at 15° and 30°C on chemically defined (meridic) diets with varied proportions of glucose and an amino acid mixture. Although the rate of larval development differed with amino acid level and rearing temperature, the important finding was an interaction between glucose and suboptimal low levels of amino acids that occurred in suboptimal low (15°C) temperature. This shows that nutritional requirements can change with temperature and is noteworthy because any relationship between the nutrition of an organism and environmental temperature can have ecological significance.