• Canada
• Publicationsclose
• Closed Access close
• Article close

What would be a genuinely caring approach to the provision of procedures of so-called artificial reproduction such as in vitro fertilization (IVF)? What are appropriate and justified social policies with respect to attempting to enable infertile persons to have offspring? These urgent questions have provoked significant disagreements among theologians, sociologists, healthcare providers, philosophers and even — or especially — among feminists. In the existing literature and in developing social policy, three different kinds of answers can be discerned. (1) Some have suggested that access to IVF should be provided as a matter of right. (2) Some existing social policies and practices imply that access to IVF is a privilege. (3) Some theorists have argued that, because of its alleged violation of family values and marital security, or because of its risks, costs, and low success rate, IVF should not be available at all. After evaluating each of these views, I shall offer a feminist alternative, describing what I think would constitute the caring provision of in vitro fertilization.

Ligation of the B cell Ag receptor (BCR) activates a protein-tyrosine kinase (PTK) and CD45 protein-tyrosine phosphatase (PTPase)-dependent signaling cascade that results in the activation of Ras. This pathway of Ras activation can operate independently of protein kinase C (PKC) activity. Activation of Ras may lead to two distinct Ras-dependent pathways involving either a Raf1/MEK/MAPK module or a MEKK/SEK/SAPK module; however, it is unclear as to how Ras controls the independent activation of either of these pathways. We have used genistein and phenylarsine oxide (PAO) as inhibitors of PTK and PTPase, respectively, to investigate whether they regulate the BCR- and Ca2+/PKC-dependent activation of the Ras/Raf1/MEK/MAPK module. Assays of phosphotransferase activities conducted with Ag (TNP6-OVA)-specific 7.9 murine B lymphoma cells demonstrated that BCR-mediated stimulation of the Raf1/MEK/MAPK module is controlled by PTK and PTPase activities. An elevation in [Ca2+]i was required to optimally activate Raf1 and MEK through the BCR. However, when signaling through the BCR was bypassed by direct stimulation of the Raf1/MEK/MAPK module via a rise in [Ca2+]i and phorbol ester-induced PKC activation, the phosphotransferase activities of Raf1, MEK and MAPK were still regulated in a PTK-dependent manner that was also partially sensitive to the PTPase inhibitor PAO. Thus, at least two alternate routes, i.e. a BCR/PTK/Ras-dependent route and another PKC/Ca(2+)-dependent route, may converge at the level of Raf1 for activation of the Raf1/MEK/MAPK module in B cells.

Objective: Research has highlighted several negative consequences for individuals born in the later part of the academic year, including increased likelihood of being diagnosed with learning disabilities. In this study, we considered whether birthdate predicted ADHD symptomatology using two well known mechanisms, the relative age effect (RAE) and the season of birth effect (SOBE). Methods: Study participants completed two ADHD measures: Conners Adult ADHD Rating Scales (CAARS) and the Wender Utah Rating Scale (WURS). Results: There were gender effects in the WURS data indicating that males scored higher than females on ADHD symptoms as well as a significant interaction in the CAARS data to support differential patterns among males and females. Conclusion: Overall, results did not support a RAE or SOBE among males or females. Possible reasons for these findings and their implications are discussed.

The base of the Proterozoic Negaunee Iron Formation is exposed in the open pit at Tilden Mine, Marquette, Michigan. Juxtaposed against the Archean-aged Palmer Gneiss, it is bounded by the regional-scale Southern Shear Zone and cut by two sets of dykes: an older chloritic and schistose set and a younger 1.1 Ga Keweenawan set. Tilden Mine is dominated by a 100 m scale plunging northwest-anticline and is cut by a growth fault locally termed the Tower Hill Fault that intersects the Southern Shear Zone. The base of the exposed iron formation is composed of three lithofacies, including lower clastics that grade into the overlying banded iron formation that in turn grades upward into granular iron formation. This succession is capped by chloritic metadiabases locally termed the Summit Hill Sill and Pillar Intrusive. Petrographic and mineral chemical investigations document primary or early diagenetic hematite, siderite and possibly ferri-hydrite, metamorphic and related hydrothermal magnetite, chlorite, late martite overgrowing earlier magnetite and growth of specularite. All three lithofacies are cut by brittle fractures and late quartz veins. Brittle fractures are coated with chlorite, carbonate minerals, fluor-apatite, and sparse Cu-sulphides. These lithofacies document initial clastic sedimentation of strained detrital quartz into a subsiding fault trough. Over time, as subsidence slowed or sea level fluctuated, clastic deposition competed with quiescent chemical sedimentation, leading to deposition of the banded iron formation facies. As a stable shelf platform emerged, the granular iron formation facies was deposited via wave reworking of hardgrounds. Subsequent diagenesis initiated dissolution of carbonate and chert and promoted diagenetic replacement of primary iron minerals and chert. Regional metamorphism during Penokean orogeny at 1875–1835 Ma produced a suite of secondary metamorphic and related hydrothermal minerals. Metamorphism and hydrothermal flux related to the 1750 Ma development of the Republic Metamorphic Node overprinted the iron formation at Tilden to greenschist facies and infilled brittle fractures with a unique mineral assemblage. This unique mineral assemblage exhibits some striking similarities to Mn, Au, and Cu-sulphides documented at Champion Mine, west of Tilden, and proximal to the core of the Republic Node.

Spinal epidural haemorrhage is a rare entity that occurs uncommonly in adults and rarely in children. It has a typical clinical presentation, although to date, the cause for the majority of cases remains unknown. We present a series of cases where epidural haemorrhage was identified at post-mortem, principly to the cervical cord, in cases outside the age range usually reported for clinical epidural haemorrhage, and with no underlying pathology to account for the finding. We present a hypothesis for a post-mortem cause for this finding and consider that, in the absence of any other identifiable causation, then this is a post-mortem occurrence similar to that of the Prinsloo-Gordon artefact of the soft tissues of the neck. This finding must be interpreted with care so as not to make the mistaken diagnosis of a nonaccidental head injury based on its finding, especially in the absence of intracranial, cranial nerve, optic nerve or eye pathologies.

Abstract We report a study of the inclusion complex of p-chlorophenol inside α-cyclodextrin (α-CD) by the theory of atoms in molecules (AIM). We use a quantitative comparison of some AIM properties of isolated p-chlorophenol (PCP) and the inclusion complex (PCP-CD) and we characterize some weak interactions within the host–guest complex. Furthermore, we compare the electrophilic aromatic substitution on the p-chlorophenol in the isolated state and inside α-CD. The analysis of the bond critical points of PCP shows that there is no trend in the effect on the AIM properties of PCP due to inclusion in the α-CD.

Due to their potential biomedical applications, protein-based hydrogels have attracted considerable interest. Although various methods have been developed to engineer self-assembling, physically-crosslinked protein hydrogels, exploring novel driving forces to engineer such hydrogels remains challenging. Protein fragment reconstitution, also known as fragment complementation, is a self-assembling mechanism by which protein fragments can reconstitute the folded conformation of the native protein when split into two halves. Although it has been used in biophysical studies and bioassays, fragment reconstitution has not been explored for hydrogel construction. Using a small protein GL5 as a model, which is capable of fragment reconstitution to reconstitute the folded GL5 spontaneously when split into two halves, GN and GC, we demonstrate that protein fragment reconstitution is a novel driving force for engineering self-assembling reversible protein hydrogels. Fragment reconstitution between GN and GC crosslinks GN and GC-containing proteins into self-assembling reversible protein hydrogels. These novel hydrogels show temperature-dependent reversible sol-gel transition, and excellent property against erosion in water. Since many proteins can undergo fragment reconstitution, we anticipate that such fragment reconstitution may offer a general driving force for engineering protein hydrogels from a variety of proteins, and thus significantly expanding the ‘toolbox’ currently available in the field of biomaterials.

Contact angle measurements for three n-alkanes, heptane, octane, and nonane, on two different self-assembled surfaces (SAM) are reported as a function of drop size. These liquids all formed low contact angles (below 20 degrees ); the measurements were performed using an accurate method for systems with low contact angle, ADSA-D. The observed drop size dependence of the contact angles was interpreted using the modified Young equation. It was concluded that the observed drop size dependence of contact angles was due to line tension. The choice of systems also provided the opportunity to examine the behavior of the line tension for systems near wetting (i.e., low contact angles). It was determined that the line tension is positive and ranges from below 10(-7) to just below 10(-6) J/m for the systems studied; the observations suggested that the line tension decreases as the contact angle decreases and likely vanishes at complete wetting.