Loss of Dynamic Stability in a Host-Parasitoid System is Related to the Magnitude and Temporal Scale of Trend in Environmental change.

Climate change is driving changes to populations leading to biodiversity crises. Knowledge is increasing on how populations are changing with research predicting how future population dynamics may predict population dynamics. Mathematical models have been an important tool to predict how biodiversity may change as the climate changes. Much research has concentrated on a ‘step change’ of the environment, but research on the effects of a gradual increase in the environmental parameters, whereby these parameters gradually increase or decrease over time, has been underexplored.To address this gap, I used a version of the Nicholson-Bailey model that has been modified to include an environmental trend, whereby, over time, the environment increases the response of the host and parasitoids intrinsic growth rate across each time step over a temporal scale, to show how this could affect population dynamics within a discrete-time host-parasitoid system and how this differs to a constant environment. I further change the magnitude and temporal scale of the trend of the environment to establish their effects on population dynamics and try to analyse the dynamics.The constant environment became unstable after an initial transient phase, when the environmental effect on the system caused the host population growth rate to reach 115% of the current population size, showing cyclic/chaotic dynamics. The trend in the environment contrasted this by almost always having stability after the initial transient phase, sometimes becoming cyclic/chaotic at a certain environmental value within the trend when population growth rate became higher than 115% of the current population size. At smaller speeds of environmental change, the population started oscillating at lower environmental parameter values than for faster speeds. This was dependent on an increase in temporal scale, causing rate of increase from one environmental value to the next to become smaller, allowing for populations to track the environmental change and shift from stability to instability at an earlier stage, whereas larger rates of increase at smaller temporal scales rather abruptly shifted from stability to sudden amplified instability.This research emphasises the need to study the effects of a trend in the environment with more intricacy and detail, to predict the future of population dynamics under different climate change scenarios

An experimental study of ice-bed separation during glacial sliding

Separation of sliding ice from hard beds plays a central role in theories of subglacial hydrology, sediment transport, and quarrying of subglacial bedrock. Despite a half-century of interest in cavities at glacier beds, there are no data establishing relationships among steady cavity size, bed geometry, sliding speed, and effective pressure. Field studies are complicated by unsteady behavior and various factors that are poorly known, including the local effective pressure at the bed, bedrock geometry, and cavity size. A laboratory ring-shear device allows sliding and ice-bed separation to be studied experimentally. The apparatus drags a ring of ice (0.9 m O.D., 0.2 m wide, 0.2 m thick) across a stepped, rigid bed. The steps are 0.18 m long and 0.027 m high along the ice-ring centerline, with treads inclined uniformly 8˚ up-flow. Sliding speed and effective pressure are controlled, while cavity volume and bed and wall temperatures are recorded. A glycol-water mixture, which is regulated to ±0.01 ˚C with an external circulator, keeps ice at the melting temperature and melt rates low. Post-experimental measurements of the ice ring\u27s basal topography provide reconstructions of cavity geometries. Ice c-axis orientations are measured throughout the ice ring using a Rigsby (universal) stage. Monotonic cavity growth towards a larger, steady size in response to increased sliding speeds was expected. Instead, cavities initially grew past their steady-state volume, followed by a series of progressively dampened oscillations above and below steady dimensions before reaching a steady size. Steady-state cavities initiated at step edges and had slightly curved roofs. Experimental cavity lengths were accurately predicted by a model based on Kamb\u27s (1987) theory of glacial surging and a new model incorporating Nye\u27s (1953) borehole closure theory. The c-axes of ice crystals at shear strains ≥ 1 formed steeply inclined, multi-maximum fabrics similar to those measured in ice at the bases of temperate glaciers

IgG Responses to Tissue-Associated Antigens as Biomarkers of Immunological Treatment Efficacy

We previously demonstrated that IgG responses to a panel of 126 prostate tissue-associated antigens are common in patients with prostate cancer. In the current report we questioned whether changes in IgG responses to this panel might be used as a measure of immune response, and potentially antigen spread, following prostate cancer-directed immune-active therapies. Sera were obtained from prostate cancer patients prior to and three months following treatment with androgen deprivation therapy (n = 34), a poxviral vaccine (n = 31), and a DNA vaccine (n = 21). Changes in IgG responses to individual antigens were identified by phage immunoblot. Patterns of IgG recognition following three months of treatment were evaluated using a machine-learned Bayesian Belief Network (ML-BBN). We found that different antigens were recognized following androgen deprivation compared with vaccine therapies. While the number of clinical responders was low in the vaccine-treated populations, we demonstrate that ML-BBN can be used to develop potentially predictive models

The Lantern Vol. 65, No. 2, Spring 1998

• Mother • The Mountain • The Record-Keeper • In Response to Bonjour monsieur Gauguin • Farewell Again • The Midwife • A Farrier by Trade • Civilization • I Don\u27t Know the Language • Friday Nights at the Fights • Naked • Ano • Unoriginal Premonition: The Series • My Muse • I\u27ve Been Slimed! • Chance in Miseryhttps://digitalcommons.ursinus.edu/lantern/1152/thumbnail.jp

Beware Zombies and Unicorns: Toward critical patient and public involvement in health research in a neoliberal context

Patient and Public Involvement (PPI) in UK National Health Service (NHS) research has become an imperative in policy and practice. However, lack of clarity on what PPI is (or might be) has given rise to a poorly monitored, complex field of activity, variously framed by the expectations of policy makers, funders, host organisations, researchers, health professionals, individual recruits, volunteers, activists and third sector organisations. The normative shift towards PPI has taken place within a neoliberal policy context, the implications of which needs to be explicitly considered, particularly after the Brexit referendum which has left policy makers and researchers wondering how to better appeal to a distrustful public subjected to ‘post-truth’ and ‘dog whistle’ politics. This commentary examines the prospects for a more critical approach to PPI which addresses context, is evidence-informed and mindful of persistent inequalities in health outcomes, at a time when models of PPI in NHS health research tend to be conceptually vague, derived from limited clinical and managerial settings, and centred on a construction of the abstract, rational, compliant and self-managing patient or lay-person

Amino Acid Patterns around Disulfide Bonds

Disulfide bonds provide an inexhaustible source of information on molecular evolution and biological specificity. In this work, we described the amino acid composition around disulfide bonds in a set of disulfide-rich proteins using appropriate descriptors, based on ANOVA (for all twenty natural amino acids or classes of amino acids clustered according to their chemical similarities) and Scheffé (for the disulfide-rich proteins superfamilies) statistics. We found that weakly hydrophilic and aromatic amino acids are quite abundant in the regions around disulfide bonds, contrary to aliphatic and hydrophobic amino acids. The density distributions (as a function of the distance to the center of the disulfide bonds) for all defined entities presented an overall unimodal behavior: the densities are null at short distances, have maxima at intermediate distances and decrease for long distances. In the end, the amino acid environment around the disulfide bonds was found to be different for different superfamilies, allowing the clustering of proteins in a biologically relevant way, suggesting that this type of chemical information might be used as a tool to assess the relationship between very divergent sets of disulfide-rich proteins

Psychosocial aspects of feeding children with neurodisability

The psychosocial support needs of parents considering a gastrostomy feeding tube for their disabled child are often overlooked, yet there is a growing body of evidence that attests to the decisional conflicts parents, often mothers, experience. This may be in addition to the stress associated with feeding a disabled child. The support needs of families and caregivers should be assessed, including the values parents attach to oral and tube feeding. Structured support should be embedded within the care pathway and both professionals, and service users, with appropriate training should be identified to ensure parental information needs, and any emotional, practical and financial issues are addressed