The Movebank data model for animal tracking

Studies of animal movement are rapidly increasing as tracking technologies make it possible to collect more data of a larger variety of species. Comparisons of animal movement across sites, times, or species are key to asking questions about animal adaptation, responses to climate and land-use change. Thus, great gains can be made by sharing and exchanging animal tracking data. Here we present an animal movement data model that we use within the Movebank web application to describe tracked animals. The model facilitates data comparisons across a broad range of taxa, study designs, and technologies, and is based on the scientific questions that could be addressed with the data.

Pattern stability and error correction during in-phase and antiphase four-ball juggling

The authors studied pattern stability and error correction during in-phase and antiphase 4-ball fountain juggling. To obtain ball trajectories, they made and digitized high-speed film recordings of 4 highly skilled participants juggling at 3 different heights (and thus different frequencies). From those ball trajectories, the authors determined and analyzed critical events (i.e., toss, zenith, catch, and toss onset) in terms of variability of point estimates of relative phase and temporal correlations. Contrary to common findings on basic instances of rhythmic interlimb coordination, in-phase and antiphase patterns were equally variable (i.e., stable). Consistent with previous findings, however, pattern stability decreased with increasing frequency. In contrast to previous results for 3-ball cascade juggling, negative lag-one correlations for catch-catch intervals were absent, but the authors obtained evidence for error corrections between catches and toss onsets. That finding may have reflected participants' high skill level, which yielded smaller errors that allowed for corrections later in the hand cycle.

Quantification of N-(glucitol)ethanolamine and N-(carboxymethyl)serine:two products of nonenzymatic modification of aminophospholipids formed in vivo

Chemical, nonenzymatic modification of protein and lipids by reducing sugars, such as glucose, is thought to contribute to age-related deterioration in tissue protein and cellular membranes and to the pathogenesis of diabetic complications. This report describes the synthesis and quantification of N-(glucitol)ethanolamine (GE) and N-(carboxymethyl)serine (CMS), two products of nonenzymatic modification of aminophospholipids. GE is the product of reduction and hydrolysis of glycated phosphatidylethanolamine (PE), while CMS is formed through reaction of phosphatidylserine (PS) with products of oxidation of either carbohydrate (glycoxidation) or lipids (lipoxidation). Gas chromatography/mass spectrometry procedures for quantification of the N,O-acetyl methyl ester derivatives of the modified head groups were developed. GE and CMS were quantified in samples of PE and PS, respectively, following incubation with glucose in vitro; CMS formation was dependent on the presence of oxygen during the incubation. Both GE and CMS were detected and quantified in lipid extracts of human red blood cell membranes. The content of GE, but not CMS, was increased in the lipids from diabetic compared to nondiabetic subjects. Measurement of these modified lipids should prove useful for assessing the role of carbonyl-amine reactions of aminophospholipids in aging and age-related diseases.

Carboxymethylethanolamine, a biomarker of phospholipid modification during the maillard reaction in vivo

Nepsilon-(Carboxymethyl)lysine (CML) is a stable chemical modification of proteins formed from both carbohydrates and lipids during autoxidation reactions. We hypothesized that carboxymethyl lipids such as (carboxymethyl)phosphatidylethanolamine (carboxymethyl-PE) would also be formed in these reactions, and we therefore developed a gas chromatography-mass spectrometry assay for quantification of carboxymethylethanolamine (CME) following hydrolysis of phospholipids. In vitro, CME was formed during glycation of dioleoyl-PE under air and from linoleoylpalmitoyl-PE, but not from dioleoyl-PE, in the absence of glucose. In vivo, CME was detected in lipid extracts of red blood cell membranes, approximately 0.14 mmol of CME/mol of ethanolamine, from control and diabetic subjects, (n = 22, p > 0.5). Levels of CML in erythrocyte membrane proteins were approximately 0.2 mmol/mol of lysine for both control and diabetic subjects (p > 0.5). For this group of diabetic subjects there was no indication of increased oxidative modification of either lipid or protein components of red cell membranes. CME was also detected in fasting urine at 2-3 nmol/mg of creatinine in control and diabetic subjects (p = 0.085). CME inhibited detection of advanced glycation end product (AGE)-modified protein in a competitive enzyme-linked immunosorbent assay using an anti-AGE antibody previously shown to recognize CML, suggesting that carboxymethyl-PE may be a component of AGE lipids detected in AGE low density lipoprotein. Measurement of levels of CME in blood, tissues, and urine should be useful for assessing oxidative damage to membrane lipids during aging and in disease.

The Landscape of Differences: Contact and Segregation in the Everyday Encounters

The article examines everyday life in Northern Ireland’s segregated communities and focus on a neglected empirical dimension of ethnic and social segregation developed within the socio-spatial relations between people and their built environment. It shows how the everyday urban encounters are reproduced through negotiating differences and the ways in which living in divided communities lead to social inequality and imbalanced use of space. The article employed qualitative research methods with individuals and community groups from the Fountain estate, a small Protestant enclave in Derry/Londonderry. Their stories were replete with cases of injustice and insights into the daily struggles that have generally occurred within theories of contact and social segregation as a whole. In fact, people in the Fountain presented their own intertextual references on what was more significant for them as a matter of routine survival and belonging, which allowed them to be more constructive about themselves. While segregation has persisted for multiple decades; time is believed to be the factor most likely to change it, as it is hoped that the younger generation will provide lasting change to Northern Ireland and eventual peace between currently segregated communities.

The Meaning of Drug Use among Homeless Young People:A longitudinal pathways analysis

A strong link between drug use and homelessness has long since been documented in the international literature. However, much of the research has concentrated on the direction of the relationship between drug use and homelessness, seeking to establish drug use as a cause or consequence of homelessness, with far less attention to the intersection of drug and homeless ‘careers’. This paper examines the drug and homeless pathways of young people who are participants in a qualitative longitudinal study of homeless youth in Dublin, Ireland. The findings highlight downward drug transitions as associated with exiting homelessness and continued or escalated consumption as associated with remaining homeless. Analyses of the meanings young people attach to drug use over time reveal the importance of housing as an enabler to engaging with treatment and as assisting the process of becoming and remaining drug free. Young people who remained homeless did not accept their situations, as ‘acculturation’ accounts would suggest; rather, they aspired to changing their situations. However, they also face strong barriers to accessing housing which in turn hamper their efforts to address the matter of their drug use. The implications for how the homeless/drug use ‘nexus’ is conceptualised and understood, as well as implications for policy, are discussed.