1,221 research outputs found
Pre- and postnatal nutritional histories influence reproductive maturation and ovarian function in the rat
No full textBackgroundWhile prepubertal nutritional influences appear to play a role in sexual maturation, there is a need to clarify the potential contributions of maternal and childhood influences in setting the tempo of reproductive maturation. In the present study we employed an established model of nutritional programming to evaluate the relative influences of prenatal and postnatal nutrition on growth and ovarian function in female offspring.MethodsPregnant Wistar rats were fed either a calorie-restricted diet, a high fat diet, or a control diet during pregnancy and/or lactation. Offspring then were fed either a control or a high fat diet from the time of weaning to adulthood. Pubertal age was monitored and blood samples collected in adulthood for endocrine analyses.ResultsWe report that in the female rat, pubertal timing and subsequent ovarian function is influenced by the animal's nutritional status in utero, with both maternal caloric restriction and maternal high fat nutrition resulting in early pubertal onset. Depending on the offspring's nutritional history during the prenatal and lactational periods, subsequent nutrition and body weight gain did not further influence offspring reproductive tempo, which was dominated by the effect of prenatal nutrition. Whereas maternal calorie restriction leads to early pubertal onset, it also leads to a reduction in adult progesterone levels later in life. In contrast, we found that maternal high fat feeding which also induces early maturation in offspring was associated with elevated progesterone concentrations.ConclusionsThese observations are suggestive of two distinct developmental pathways leading to the acceleration of pubertal timing but with different consequences for ovarian function. We suggest different adaptive explanations for these pathways and for their relationship to altered metabolic homeostasis
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GJ 3929: High-precision Photometric and Doppler Characterization of an Exo-Venus and Its Hot, Mini-Neptune-mass Companion
No full textWe detail the follow-up and characterization of a transiting exo-Venus identified by TESS, GJ 3929b (TOI-2013b), and its nontransiting companion planet, GJ 3929c (TOI-2013c). GJ 3929b is an Earth-sized exoplanet in its star’s Venus zone (P b = 2.616272 ± 0.000005 days; Sb = 17.3 − 0.7 + 0.8 S ⊕) orbiting a nearby M dwarf. GJ 3929c is most likely a nontransiting sub-Neptune. Using the new, ultraprecise NEID spectrometer on the WIYN 3.5 m Telescope at Kitt Peak National Observatory, we are able to modify the mass constraints of planet b reported in previous works and consequently improve the significance of the mass measurement to almost 4σ confidence (M b = 1.75 ± 0.45 M ⊕). We further adjust the orbital period of planet c from its alias at 14.30 ± 0.03 days to the likely true period of 15.04 ± 0.03 days, and we adjust its minimum mass to m sin i = 5.71 ± 0.92 M ⊕. Using the diffuser-assisted ARCTIC imager on the ARC 3.5 m telescope at Apache Point Observatory, in addition to publicly available TESS and LCOGT photometry, we are able to constrain the radius of planet b to R p = 1.09 ± 0.04 R ⊕. GJ 3929b is a top candidate for transmission spectroscopy in its size regime (TSM = 14 ± 4), and future atmospheric studies of GJ 3929b stand to shed light on the nature of small planets orbiting M dwarfs. © 2022. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
The Optimization of the Performance Management for Operators in GJ Company Xiamen
No full text本文以绩效管理的基本理论和GJ厦门厂的实际情况为基础，分析了GJ厦门厂一线作业员绩效管理的问题点，并结合公司目前的实际情况提出一线作业员的绩效管理改善方案。该方案以平衡计分卡的绩效管理体系为逻辑，将公司的战略目标分解到制造处，再分解至一线作业员，让作业员的绩效也能从财务面、客户面、内部运营面、学习成长面四个维度上对公司的战略发展起到支撑作用，以促进组织战略目标的实现。 在绩效管理改进方案中，作者特别强调沟通在绩效管理过程中的重要作用，它贯穿了绩效管理的整个过程。沟通有助于促进员工个人绩效的提升和员工个人的成长，从而提升组织的整体效益。 根据GJ厦门厂的实际情况，将一线作业员的绩效考核结...In this paper, operators’ performance management problems in GJ Company are analyzed based on the basic theory of performance management and the real situation of the company. The author propose to break down the company’s strategic targets to lower levels with balanced scorecard system by four levels of financial, customer, internal operation, learning and developing. So that operators’ performa...学位：管理学硕士院系专业：管理学院_工商管理硕士(工商管理硕士)学号：1792012115103
Exergy comparison of lunar propellant manufacturing and insertion into LEO using a fully reusable refueling rocket
No full textQuantifying the exergy requirement of propellant insertion into LEO can lead to insight into the feasibility of a lunar propellant-generating architecture. Spacecraft leaving from Earth can greatly reduce their lift-off mass if in-space refueling would possible. Exergy analyses quantify the available energy of a system and show where a reduction in usable energy occurs. Insight into the exergy destruction and input provides a key parameter into the scaling and design of processes and corresponding power systems. The present study aims to define an exergy environment in the lunar PSRs and then to analyze the exergy destruction related to the production of oxygen, ALICE, and hydrolox, in terms of both manufacturing and transportation using a two-stage fully reusable rocket. Extraction processes for ALICE and hydrolox were selected and analyzed w.r.t. the lunar environment to get an understanding of the exergy input. The behavior and exergy requirements of an LEO propellant depot was described. Two fully reusable two-stage rockets using ALICE and hydrolox were designed and compared based on their payload-to-propellant ratio for the oxygen, ALICE, and hydrolox payloads. The study found that the exergetic cost for the insertion of oxygen, hydrolox, and ALICE in LEO were 1.32 GJ/kg , 1.64 GJ/kg, and GJ/kg and 23.3 GJ/kg, 23.4 GJ/kg and 26.9 GJ/kg for the hydrolox and ALICE rocket, respectively.Aerospace Engineerin
Crystallisation of PFA glasses
No full textBibliography: leaves 79-81.Glasses with various compositions, falling in the CaO-AI20rSi02 and MgO-CaOAI20rSi02 systems were made, using pulverised fuel ash and silica, hydrated lime, kaolin and magnesium carbonate. Titania or ferric oxide and chromia were used as nucleants. Various crystallisation heat treatments were carried out and the nucleation and crystallisation behaviour was studied. A minimum MgO:CaO was found to be necessary for bulk nucleation to occur. The activation energy for viscous flow decreased with increased MgO:CaO ratios. This was accompanied by an increase in the surface crystal growth rates and a decrease in the activation energy for surface crystal growth. Titania also lowered the activation energies for viscous flow and surface crystal growth and caused an increase in the surface crystal growth rates
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Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H
No full textThe search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such planets have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since the expected signal strength of atmospheric features is similar to the single-transit performance of JWST, multiple observations are required to confirm any detection. Here, we present two transit observations of the rocky planet GJ 1132 b with JWST NIRSpec G395H, covering 2.8-5.2 μm. Previous Hubble Space Telescope WFC3 observations of GJ 1132 b were inconclusive, with evidence reported for either an atmosphere or a featureless spectrum based on analyses of the same data set. Our JWST data exhibit substantial differences between the two visits. One transit is consistent with either an H2O-dominated atmosphere containing ∼1% CH4 and trace N2O ( χ ν 2 = 1.13 ) or stellar contamination from unocculted starspots ( χ ν 2 = 1.36 ). However, the second transit is consistent with a featureless spectrum. Neither visit is consistent with a previous report of HCN. Atmospheric variability is unlikely to explain the scale of the observed differences between the visits. Similarly, our out-of-transit stellar spectra show no evidence of changing stellar inhomogeneity between the two visits—observed 8 days apart, only 6.5% of the stellar rotation rate. We further find no evidence of differing instrumental systematic effects between visits. The most plausible explanation is an unlucky random noise draw leading to two significantly discrepant transmission spectra. Our results highlight the importance of multivisit repeatability with JWST prior to claiming atmospheric detections for these small, enigmatic planets. © 2023. The Author(s). Published by the American Astronomical Society.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Ves v 5 can establish the diagnosis in patients without detectable specific IgE to wasp venom and a possible north-south difference in Api m 1 sensitization in Europe.
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High sensitivity of CAP-FEIA rVes v 5 and rVes v 1 for diagnosis of Vespula venom allergy. [J Allergy Clin Immunol. 2012
Periprosthetic osteolysis is associated with wear particles stimulating factors that control osteoclast formation
No full textAbstract onlyWear particles are thought to be a major factor causing osteolysis that leads to aseptic loosening. The aim of this study was to investigate the role of primary regulators of osteoclast development, RANKL (also known as osteoclast differentiation factor), its receptor RANK and natural inhibitor osteoprotegerin (OPG) in aseptic loosening. Cells were isolated from periprosthetic tissues taken at revision from more than 30 patients and the expression of these mediators in vivo was assessed using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). These cells were also cultured on dentine to determine their ability to become mature osteoclasts. In situ hybridisation using DIG labelled riboprobes specific for RANK mRNA was used to identify cells likely to become osteoclasts. We were able to compare revison tissues containing several different types of prosthetic wear particles. RANKL, RANK and OPG mRNA were found in samples of periprosthetic revision tissues. Cells derived from this tissue developed into mature osteoclasts capable of resorbing dentine. Cells that rapidly formed osteoblasts expressed a fifteen fold higher ratio of RANKL:OPG mRNA. In situ hybridisation showed RANK expression by macrophages and giant cells, many of which contained wear particles. Significantly, cells from tissues containing silastic wear particles expressed higher levels of RANKL relative to OPG and more produced large numbers of osteoclasts in vitro. This study shows that different bio materials in a particulate form may differ in their ability to form osteoclasts and that the relative levels of RANKL and OPG are likely to be important in determining if osteolysis will occur. In the future molecules that inhibit RANKL binding, such as OPG, may be considered for therapy of periprosthetic osteolysis.TN Crotti, M Loric, GJ Atkins, DM Findlay, DW Howie, G Bain and DR Hayne
Diagnosing Intermittent Faults
No full textIn this working report we outline how to determine the intermittency parameters gj from the activity matrix A (context: DX’08 paper Abreu, Zoeteweij, Van Gemund). We start with the single fault (SF) case and show that averaging over the error vector e is the exact way. We also show that in this way the probability of obtaining exactly this e vector in A is optimal. This is the key insight that allows us to determine g in the general multiple-fault (MF) case. We formulate the gj problem as a (probability) maximization problem, which we solve using a simple gradient ascent technique.Software Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc
Testing contributor & translator roles - harvest
No full textGJ author, edited to add dc.contributor and dc.contributor.translator; cc-by-nc-n
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