Dietary plasticity and broad North Atlantic origins inferred from bulk and amino acid-specific δN and δC favour killer whale range expansions into Arctic waters.

Killer whales (Orcinus orca) occur seasonally in the eastern Canadian Arctic (ECA), where their range expansion associated with declining sea ice have raised questions about the impacts of increasing killer whale predation pressure on Arctic-endemic prey. We assessed diet and distribution of ECA killer whales using bulk and compound-specific stable isotope analysis (CSIA) of amino acids (AA) of 54 skin biopsies collected from 2009 to 2020 around Baffin Island, Canada. Bulk ECA killer whale skin δN and δC values did not overlap with potential Arctic prey after adjustment for trophic discrimination, and instead reflected foraging history in the North Atlantic prior to their arrival in the ECA.

Larger body size leads to greater female beluga whale ovarian reproductive activity at the southern periphery of their range.

Identification of phenotypic characteristics in reproductively successful individuals provides important insights into the evolutionary processes that cause range shifts due to environmental change. Female beluga whales () from the Baffin Bay region (BB) of the Canadian Arctic in the core area of the species' geographic range have larger body size than their conspecifics at the southern range periphery in Hudson Bay (HB). We investigated the mechanism for this north and south divergence as it relates to ovarian reproductive activity (ORA = total corpora) that combines morphometric data with ovarian corpora counted from female reproductive tracts.

Pride and prejudice: factors affecting school attachment among lesbian, bisexual, and heterosexual girls.

School attachment is often regarded as a key measure in gauging the integration and wellbeing of students. Previous research suggests that levels of school attachment are generally lower among sexual minority students, but most studies focus on between-gender comparisons and do not conduct within-gender analyses. Using data from the First National Climate Survey on Homophobia and Transphobia in Canadian schools, this study set out to empirically analyze what, if any, differences exist among lesbian, bisexual, and heterosexual female students when assessing the relationship between homophobic and gender-negative language, feelings of safety, harassment/direct victimization, and school climate on school attachment.

Development and validation of novel enzyme activity methods to assess inhibition of matrix metalloproteinases (MMPs) in human serum by antibodies against enzyme therapeutics.

This paper summarizes the development and validation of five enzyme activity methods to assess the specific inhibition of human endogenous matrix metalloproteinases MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-8 (collagenase 2) and MMP-13 (collagenase 3) by anti-Collagenase Clostridium histolyticum (CCH) antibodies in human serum. These MMPs are of interest since antibodies against a therapeutic enzyme may cross-react with, and inactivate, the MMPs. The validated methods utilize spiked exogenous individual MMPs added to serum to determine if the serum inhibits MMP enzyme activity.

Assessment of potential cross-reactivity of human endogenous matrix metalloproteinases with collagenase Clostridium histolyticum antibodies in human sera obtained from patients with Dupuytren's contracture.

Collagenase Clostridium histolyticum (CCH) contains a fixed ratio of class I (AUX-I) and class II (AUX-II) collagenases and is used as treatment for Dupuytren's contracture. These two Zn-dependent enzymes, produced by the Gram-positive bacterium Clostridium histolyticum, are related functionally to matrix metalloproteinases (MMPs) which, among other functions, degrade the extracellular matrix. Since AUX-I and AUX-II exhibit sequence similarities to human MMPs, we assessed MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-8 (collagenase 2), and MMP-13 (collagenase 3) for cross-reactivity with anti-AUX-I and anti-AUX-II antibodies in patient serum.

Development of a bimodal polarimetric response model for improved quantitation of enantiomeric mixtures under conditions of poor chromatographic resolution.

The combination of a chiral-selective separation mode with polarimetric detection was investigated in terms of its ability to quantitate enantiomeric mixtures of the dansylated derivatives of phenylalanine, threonine, and valine under conditions of poor chromatographic resolution. Using the difference between two Gaussian functions to model the bimodal response obtained using polarimetric detection and incomplete chiral resolution, correlation coefficients as high as 0.999 were obtained when actual enantiomeric fractions were plotted against observed enantiomeric fractions calculated from the fitting procedure.

Quantitative analysis of incomplete HPLC resolution of enantiomers. Fit of polarimetric detection for D- and L-phenylalanine to a gaussian function.

This report compares laser-based polarimetric and UV data for quantitating incompletely resolved enantiomers by HPLC. Using L- and D-phenylalanine as a working model, response data is shown across the entire detection region while emphasizing the regions at or near 100% L, 100% D and 50:50 L:D at resolutions between 0.4 and 1.

Determination of enantiomeric excess using a chiral selective separation mode and polarimetric detection.

The quantitative capabilities of a system that combines a chiral selective separation mode with polarimetric detection (CSS/PD) were investigated in terms of the ability to quantitate enantiomeric mixtures even under conditions of poor chromatographic resolution. The laser-based polarimetric detection system can provide a rotational sensitivity on the order of 10 mudeg corresponding to a minimum measurable quantity of 10 ng for a compound with a specific rotation of 100 deg (g/ml)(-1) dm(-1). For the chromatographic studies, peak height and peak area were measured as analytical descriptors of the bimodal response function of this polarimetric detector.

Genetic counselling and gene mutation analysis in familial adenomatous polyposis in Western Australia.

Objective: To assess the provision of accurate pre-symptomatic genetic testing with DNA analysis and appropriate counselling for individuals and families known to be at high risk of developing familial adenomatous polyposis coli (FAP).

Patients And Methods: Thirty-one families with clinically and pathologically documented FAP were ascertained from the Western Australian Polyposis Registry. DNA was collected from over 200 individuals in these families to establish their genetic risk status for FAP, either by direct mutation analysis, or by linkage analysis.

Mutation analysis of Western Australian families affected by cystic fibrosis.

Objective: To document the results of mutation analysis on 160 individuals with cystic fibrosis and 31 obligate carriers of the cystic fibrosis gene in 191 Western Australian families to facilitate accurate genetic counselling.

Methods: We tested for 17 mutations of the cystic fibrosis gene by either a variation of the polymerase chain reaction amplification refractory mutation system (PCR-ARMS) or with a series of restriction enzyme cuts and dot blots using chemiluminescent probes.

Results: At least one of the two intragenic mutations causing cystic fibrosis was identified in 98% of affected individuals and both were detected in 68%.