The Mission of Catholic High Schools and Today’s Millennials: Three Suggestions

A new generation of American Catholics, called the millennial generation, has emerged. This article examines how millennials think about their world, their Church, and their schools; discusses how and why their thinking will change as they mature; and offers research-based suggestions on how best to present the Catholic tradition to them

Mathematically optimized cryoprotectant equilibration procedures for cryopreservation of human oocytes

Background Simple and effective cryopreservation of human oocytes would have an enormous impact on the financial and ethical constraints of human assisted reproduction. Recently, studies have demonstrated the potential for cryopreservation in an ice-free glassy state by equilibrating oocytes with high concentrations of cryoprotectants (CPAs) and rapidly cooling to liquid nitrogen temperatures. A major difficulty with this approach is that the high concentrations required for the avoidance of crystal formation (vitrification) also increase the risk of osmotic and toxic damage. We recently described a mathematical optimization approach for designing CPA equilibration procedures that avoid osmotic damage and minimize toxicity, and we presented optimized procedures for human oocytes involving continuous changes in solution composition. Methods Here we adapt and refine our previous algorithm to predict piecewise-constant changes in extracellular solution concentrations in order to make the predicted procedures easier to implement. Importantly, we investigate the effects of using alternate equilibration endpoints on predicted protocol toxicity. Finally, we compare the resulting procedures to previously described experimental methods, as well as mathematically optimized procedures involving continuous changes in solution composition. Results For equilibration with CPA, our algorithm predicts an optimal first step consisting of exposure to a solution containing only water and CPA. This is predicted to cause the cells to initially shrink and then swell to the maximum cell volume limit. To reach the target intracellular CPA concentration, the cells are then induced to shrink to the minimum cell volume limit by exposure to a high CPA concentration. For post-thaw equilibration to remove CPA, the optimal procedures involve exposure to CPA-free solutions that are predicted to cause swelling to the maximum volume limit. The toxicity associated with these procedures is predicted to be much less than that of conventional procedures and comparable to that of the corresponding procedures with continuous changes in solution composition. Conclusions The piecewise-constant procedures described in this study are experimentally facile and are predicted to be less toxic than conventional procedures for human oocyte cryopreservation. Moreover, the mathematical optimization approach described here will facilitate the design of cryopreservation procedures for other cell types.This work was supported by a National Science Foundation grant (#1150861) to Adam Higgins. This article is made openly accessible in part by an award from the Northern Illinois University Libraries’ Open Access Publishing Fund

Observation of Intralaminar Cracking in the Edge Crack Torsion Specimen

The edge crack torsion (ECT) test is evaluated to determine its suitability for measuring fracture toughness associated with mode III delamination growth onset. A series of ECT specimens with preimplanted inserts with different lengths is tested and examined using nondestructive and destructive techniques. Ultrasonic inspection of all tested specimens reveals that delamination growth occurs at one interface ply beneath the intended midplane interface. Sectioning and optical microscopy suggest that the observed delamination growth results from coalescence of angled intralaminar matrix cracks that form and extend across the midplane plies. The relative orientation of these cracks is approximately 45 deg with respect to the midplane, suggesting their formation is caused by resolved principal tensile stresses arising due to the global mode-III shear loading. Examination of ECT specimens tested to loads below the level corresponding to delamination growth onset reveals that initiation of intralaminar cracking approximately coincides with the onset of nonlinearity in the specimen's force-displacement response. The existence of intralaminar cracking prior to delamination growth onset and the resulting delamination extension at an unintended interface render the ECT test, in its current form, unsuitable for characterization of mode III delamination growth onset. The broader implications of the mechanisms observed in this study are also discussed with respect to the current understanding of shear-driven delamination in tape-laminate composites

SPIFI: a Direct-Detection Imaging Spectrometer for Submillimeter Wavelengths

The South Pole Imaging Fabry-Perot Interferometer (SPIFI) is the first instrument of its kind -a direct-detection imaging spectrometer for astronomy in the submillimeter band. SPIFI ’s focal plane is a square array of 25 silicon bolometers cooled to 60 mK; the spectrometer consists of two cryogenic scanning Fabry-Perot interferometers in series with a 60-mK bandpass filter. The instrument operates in the short submillimeter windows (350 and 450 μm) available from the ground, with spectral resolving power selectable between 500 and 10,000. At present, SPIFI’s sensitivity is within a factor of 1.5-3 of the photon background limit, comparable with the best heterodyne spectrometers. The instrument ’s large bandwidth and mapping capability provide substantial advantages for specific astrophysical projects, including deep extragalactic observations. We present the motivation for and design of SPIFI and its operational characteristics on the telescope

Age-related differences in breast cancer mortality according to race/ethnicity, insurance, and socioeconomic status.

BackgroundWe assessed breast cancer mortality in older versus younger women according to race/ethnicity, neighborhood socioeconomic status (nSES), and health insurance status.MethodsThe study included female breast cancer cases 18 years of age and older, diagnosed between 2005 and 2015 in the California Cancer Registry. Multivariable Cox proportional hazards modeling was used to generate hazard ratios (HR) of breast cancer specific deaths and 95% confidence intervals (CI) for older (60+ years) versus younger (< 60 years) patients separately by race/ethnicity, nSES, and health insurance status.ResultsRisk of dying from breast cancer was higher in older than younger patients after multivariable adjustment, which varied in magnitude by race/ethnicity (P-interaction< 0.0001). Comparing older to younger patients, higher mortality differences were shown for non-Hispanic White (HR = 1.43; 95% CI, 1.36-1.51) and Hispanic women (HR = 1.37; 95% CI, 1.26-1.50) and lower differences for non-Hispanic Blacks (HR = 1.17; 95% CI, 1.04-1.31) and Asians/Pacific Islanders (HR = 1.15; 95% CI, 1.02-1.31). HRs comparing older to younger patients varied by insurance status (P-interaction< 0.0001), with largest mortality differences observed for privately insured women (HR = 1.51; 95% CI, 1.43-1.59) and lowest in Medicaid/military/other public insurance (HR = 1.18; 95% CI, 1.10-1.26). No age differences were shown for uninsured women. HRs comparing older to younger patients were similar across nSES strata.ConclusionOur results provide evidence for the continued disparity in Black-White breast cancer mortality, which is magnified in younger women. Moreover, insurance status continues to play a role in breast cancer mortality, with uninsured women having the highest risk for breast cancer death, regardless of age

Angular versus radial correlation effects on momentum distributions of light two-electron ions

We investigate different correlation mechanisms for two-electron systems and compare their respective effects on various electron distributions. The simplicity of the wave functions used allows for the derivation of closed-form analytical expressions for all electron distributions. Among other features, it is shown that angular and radial correlation mechanisms have opposite effects on Compton profiles at small momenta.Comment: 22 pages, 5 figures, 3 tabl

Mechanical Characterisation of Pneumatically-Spliced Carbon Fibre Yarns as Reinforcements for Polymer Composites

An investigation into the mechanical response of pneumatically-spliced carbon fibre yarns as a potential reinforcing material for polymer composites is presented. High strength mechanical connections between carbon fibre yarns are produced by joining short discontinuous tows into longer lengths via fibre entanglement. The effect of altering the number of high-pressure air pulses fired by a commercially available (Airbond 701H) splicing machine, to form the tow-tow connection, on load bearing capacity and linear stiffness is first evaluated on splices between virgin T700SC-24K-50C carbon fibre tows. The best performing spliced configuration is subsequently utilised in reinforcing unidirectional epoxy laminates, which are mechanically characterised, and their properties compared to those of various continuous fibre and chopped strand mat panels. Results presented in this study demonstrate that pneumatic splicing provides a high strength and sustainable solution for reinforcing polymers with discontinuous (approx. >50 mm in length) virgin, off-cut or waste carbon fibre yarns. It is speculated that with further research, quasi-continuous yarns remanufactured by splicing waste fibres could provide a novel material for weaving, braiding, non-crimp fabrics, or use in 3D printing applications

Glucocorticoid Regulation of Elastin Synthesis in Human Fibroblasts: Down-Regulation in Fibroblasts from Normal Dermis But Not From Keloids

Keloids arise as benign connective tissue masses at sites of injury in genetically predisposed individuals, In addition to excessive collagen accumulation, there is biochemical and histologic evidence of elastic tissue. Previous studies showed that glucocorticoid regulation of collagen synthesis differs in fibroblasts from normal adult dermis and keloids, To define further the abnormal regulation of matrix synthesis in keloid fibroblasts, we examined glucocorticoid regulation of elastin synthesis. The basal level of elastin synthesis was significantly higher in keloid than in normal cells, and hydrocortisone reduced synthesis of elastin and elastin mRNA in normal but not in keloid fibroblasts. We had shown previously that fibroblasts from fetal dermis resembled keloid fibroblasts in glucocorticoid regulation of growth and collagen synthesis. In this study, glucocorticoids failed to down-regulate elastin synthesis in fetal cells that had not differentiated to produce normal levels of elastin, whereas fetal cells with normal elastin production exhibited glucocorticoid down-regulation. Abnormal regulation in keloid cells was independent of cell density and was confined to fibroblasts cultured from the keloid nodule. These findings reinforce the conclusion that a matrix-regulatory pathway is deranged in these focal lesions. Coordinate down-regulation of collagen and elastin by hydrocortisone in normal adult denial fibroblasts and the failure of hydrocortisone to down-regulate synthesis of either protein in keloid cells support the existence of common elements in the regulatory pathways of these two matrix proteins