Unconstrained noninvasive vital signs monitoring for detection of obstructive sleep apnea with automated prevention

The Bioengineering Laboratory at UNH has demonstrated the usefulness of medical device interoperability through previous work that involved connecting an advanced hospital bed with blood pressure monitors over an electrical communication bus known as Controller Area Network (CAN). The medical devices utilize the software communication protocol known as CANopen for communicating relevant patient data to one another. This thesis explores the opportunity to detect a person\u27s heartbeat and respiration while lying in a hospital bed noninvasively and unconstrained for accurately identifying an episode of obstructive sleep apnea. The design and development of this device is a CANopen compatible therapeutic automatic bed adjustment to counteract a sleep apnea episode by restoring a person to normal respiratory sleep

The importance of replicating genomic analyses to verify phylogenetic signal for recently evolved lineages

Genomewide SNP data generated by nontargeted methods such as RAD and GBS are increasingly being used in phylogenetic and phylogeographic analyses. When these methods are used in the absence of a reference genome, however, little is known about the locations and evolution of the SNPs. In using such data to address phylogenetic questions, researchers risk drawing false conclusions, particularly if a representative number of SNPs is not obtained. Here, we empirically test the robustness of phylogenetic inference based on SNP data for closely related lineages. We conducted a genomewide analysis of 75 712 SNPs, generated via GBS, of southern bull-kelp (Durvillaea). Durvillaea chathamensis co-occurs with D. antarctica on Chatham Island, but the two species have previously been found to be so genetically similar that the status of the former has been questioned. Our results show that D. chathamensis, which differs from D. antarctica ecologically as well as morphologically, is indeed a reproductively isolated species. Furthermore, our replicated analyses show that D. chathamensis cannot be reliably distinguished phylogenetically from closely related D. antarctica using subsets (ranging in size from 400 to 10 000 sites) of the 40 912 parsimony-informative SNPs in our data set and that bootstrap values alone can give misleading impressions of the strength of phylogenetic inferences. These results highlight the importance of independently replicating SNP analyses to verify that phylogenetic inferences based on nontargeted SNP data are robust. Our study also demonstrates that modern genomic approaches can be used to identify cases of recent or incipient speciation that traditional approaches (e.g. Sanger sequencing of a few loci) may be unable to detect or resolve.This research was supported by an Australian Research Council Discovery Early Career Research Award (DE140101715 to CIF) and University of Otago Performance Based Research Funding (to JMW)

Theory of high-energy emission from the pulsar/Be-star system PSR 1259−-63 I: radiation mechanisms and interaction geometry

We study the physical processes of the PSR B1259-63 system containing a 47 ms pulsar orbiting around a Be star in a highly eccentric orbit. Motivated by the results of a multiwavelength campaign during the January 1994 periastron passage of PSR B1259-63, we discuss several issues regarding the mechanism of high-energy emission. Unpulsed power law emission from the this system was detected near periastron in the energy range 1-200 keV. We find that the observed high energy emission from the PSR B1259-63 system is not compatible with accretion or propeller-powered emission. Shock-powered high-energy emission produced by the pulsar/outflow interaction is consistent with all high energy observations. By studying the evolution of the pulsar cavity we constrain the magnitude and geometry of the mass outflow outflow of the Be star. The pulsar/outflow interaction is most likely mediated by a collisionless shock at the internal boundary of the pulsar cavity. The system shows all the characteristics of a {\it binary plerion} being {\it diffuse} and {\it compact} near apastron and periastron, respectively. The PSR B1259-63 cavity is subject to different radiative regimes depending on whether synchrotron or inverse Compton (IC) cooling dominates the radiation of electron/positron pairs advected away from the inner boundary of the pulsar cavity. The highly non-thermal nature of the observed X-ray/gamma-ray emission near periastron establishes the existence of an efficient particle acceleration mechanism within a timescale shown to be less than $\sim 10^2-10^3$ s. A synchrotron/IC model of emission of e\pm-pairs accelerated at the inner shock front of the pulsar cavity and adiabatically expanding in the MHD flow provides an excellent explanation of the observed time variableX-ray flux and spectrum from the PSRComment: 68 pages, accepted for publication in the Astrophys. J. on Aug. 26, 199

Cell surface proteins of the neutrophil in relation to chronic myeloid leukaemia

A large number of studies now suggest that non-random chromosomal changes are associated with human cancers. Certain chromosomes are involved more frequently in rearrangements, duplications and deletions than would be expected by chance. The most consistently observed chromosome abnormality is the Philadelphia chromosome, (Ph') which is found in a number of heamopoetic cell lineages in some 90% of patients sufferring from chronic myeloid leukaemia, (CML). Despite the diagnostic significance of the Ph' chromosome virtually nothing is known about its role in the origin and development of the disease. Well established phenotypic alterations in the mature neutrophil in CML are limited to the finding of a reduced level of alkaline phophatase in these cells. However, membrane-related phenomena, including phagocytosis and lectin agglutination have been shown to be altered. This study was undertaken to determine whether simple consistent alterations in cell membrane proteins were detectable at the molecular level which might underlie the membrane-related phenomena noted above and could be related to the chromosomal changes which occur in this leukaemia. Labelling of the membrane proteins of the cell chosen for study, the neutrophil, revealed at least thirteen relatively high molecular weight polypeptides bands which were identified using the 125I-lactoperoxidase labelling technique, on SDS-PAGE. To demonstrate that the labelled polypeptides were present on the cell surface, three independent methods were used: plasma membrane isolation, trypsin sensitivity and labelling in the presence and absence of exogenous enzymes. Extraction with the non-ionic detergent, Triton X-100 considerably reduced problems of handling and proteolytic digestion associated with this cell. Evidence is presented that non-ionic detergents, (TX-100 and NP-40), extract polypeptides selectively which may have structural significance. One major coomassie blue staining band, of mol. wt. 85K, a minor band of mol. wt. 25K and one broad radiolabelled band of mol. wt. 55-60K were particularly selectively retained in a residual pellet. Experiments using Concanavalin A (Con A) affinity chromatography showed that most of the labelled polypeptides were glycosylated. One major band was unique in that it showed no binding to Con A either by affinity chromatography or by the use of 125I-Con A overlay on SDS-PAGE. It is the major cell surface receptor for Wheat Germ Agglutinin (WGA) which binds to terminal sialic acid residues. when labelled cells were treated with neuraminidase there was an apparent decrease in the mobility of this polypeptide and binding to WGA was abolished. No other labelled band showed significant alteration following neuraminidase treatment. The above evidence suggests that this glycoprotein of mol. wt. 115K approx., (Gp 115K), is the major sialoglycoprotein at the cell surface of the human neutrophil. This finding may be of general interest since it shares a number of the features, described above, with other 'glycophorin-like' sialoglycoproteins reported in the literature. The function of this unusual class of cell surface glycoproteins is not clear, but they appear to make a significant contribution to the net negative charge at the cell surface and to lack secondary or tertiary structure in the extracellular portion. Membrane related phenomena of the human neutrophil appear to undergo alterations in CML. Cell surface polypeptides were labelled directly using the 125I-LPO method and radio-labelled lectins (Con A and WGA) were overlayed on whole cell detergent extracts run on SDS-PAGE, in order to try and detect alterations in glycosylation. The results suggest that large scale alterations in the expression of glycosylated, and in particular cel1-surface, proteins do not occur. No evidence for novel gene products or marked alteration in glycosylation of neutrophils in CML was found

Contemporary habitat discontinuity and historic glacial ice drive genetic divergence in Chilean kelp

<p>Abstract</p> <p>Background</p> <p>South America's western coastline, extending in a near-straight line across some 35 latitudinal degrees, presents an elegant setting for assessing both contemporary and historic influences on cladogenesis in the marine environment. Southern bull-kelp (<it>Durvillaea antarctica</it>) has a broad distribution along much of the Chilean coast. This species represents an ideal model taxon for studies of coastal marine connectivity and of palaeoclimatic effects, as it grows only on exposed rocky coasts and is absent from beaches and ice-affected shores. We expected that, along the central Chilean coast, <it>D. antarctica </it>would show considerable phylogeographic structure as a consequence of the isolating effects of distance and habitat discontinuities. In contrast, we hypothesised that further south - throughout the region affected by the Patagonian Ice Sheet at the Last Glacial Maximum (LGM) - <it>D. antarctica </it>would show relatively little genetic structure, reflecting postglacial recolonisation.</p> <p>Results</p> <p>Mitochondrial (COI) and chloroplast (<it>rbc</it>L) DNA analyses of <it>D. antarctica </it>from 24 Chilean localities (164 individuals) revealed two deeply divergent (4.5 - 6.1% for COI, 1.4% for <it>rbc</it>L) clades from the centre and south of the country, with contrasting levels and patterns of genetic structure. Among populations from central Chile (32° - 44°S), substantial phylogeographic structure was evident across small spatial scales, and a significant isolation-by-distance effect was observed. Genetic disjunctions in this region appear to correspond to the presence of long beaches. In contrast to the genetic structure found among central Chilean populations, samples from the southern Chilean Patagonian region (49° - 56°S) were genetically homogeneous and identical to a haplotype recently found throughout the subantarctic region.</p> <p>Conclusions</p> <p>Southern (Patagonian) Chile has been recolonised by <it>D. antarctica </it>relatively recently, probably since the LGM. The inferred trans-oceanic ancestry of these Patagonian populations supports the notion that <it>D. antarctica </it>is capable of long-distance dispersal via rafting. In contrast, further north in central Chile, the correspondence of genetic disjunctions in <it>D. antarctica </it>with long beaches indicates that habitat discontinuity drives genetic isolation among established kelp populations. We conclude that rafting facilitates colonisation of unoccupied shores, but has limited potential to enhance gene-flow among established populations. Broadly, this study demonstrates that some taxa may be considered to have either high or low dispersal potential across different temporal and geographic scales.</p

The effect of weak inertia in rotating high-aspect-ratio vessel bioreactors

One method to grow artificial body tissue is to place a porous scaffold seeded with cells, known as a tissue construct, into a rotating bioreactor filled with a nutrient-rich fluid. The flow within the bioreactor is affected by the movement of the construct relative to the bioreactor which, in turn, is affected by the hydrodynamical and gravitational forces the construct experiences. The construct motion is thus coupled to the flow within the bioreactor. Over the timescale of a few hours, the construct appears to move in a periodic orbit but, over tens of hours, the construct drifts from periodicity. In the biological literature, this effect is often attributed to the change in density of the construct that occurs via tissue growth. In this paper, we show that weak inertia can cause the construct to drift from its periodic orbit over the same timescale as tissue growth. We consider the coupled flow and construct motion problem within a rotating high-aspect- ratio vessel bioreactor. Using an asymptotic analysis, we investigate the case where the Reynolds number is large but the geometry of the bioreactor yields a small reduced Reynolds number, resulting in a weak inertial effect. In particular, to accurately couple the bioreactor and porous flow regions, we extend the nested boundary layer analysis of Dalwadi et al. (J. Fluid Mech. vol. 798, pp. 88–139, 2016) to include moving walls and the thin region between the porous construct and the bioreactor wall. This allows us to derive a closed system of nonlinear ordinary differential equations for the construct trajectory, from which we show that neglecting inertia results in periodic orbits; we solve the inertia-free problem analytically, calculating the periodic orbits in terms of the system parameters. Using a multiple-scale analysis, we then systematically derive a simpler system of nonlinear ordinary differential equations that describe the long-time drift of the construct due to the effect of weak inertia. We investigate the bifurcations of the construct trajectory behaviour, and the limit cycles that appear when the construct is less dense than the surrounding fluid and the rotation rate is large enough. Thus, we are able to predict when the tissue construct will drift towards a stable limit cycle within the bioreactor and when it will drift out until it hits the bioreactor edg

The ecology of peer review: Person-centred, strength-based, and self-determination perspectives

The peer-review system, commonly considered critical for research integrity and rigour, has been criticised for being slow, exclusionary and exploitive. Concerns include the high profits of academic publishers as well as the growing number of insecurely employed academic staff who report high levels of stress and burnout. The consequence has been a decline in willing reviewers, publication delays, and potential damage to the career trajectories of early career researchers and PhD candidates at institutions that rely on metrics of academic impact as measures of academic performance. Rather than overhaul the system and undermine current benefits, this critical review adopts an ecological lens to posit an approach that is humanistic, transparent, and above all things, kind. This approach frames an applied perspective on how to improve peer-review moving forward

Genetic affinities between trans-oceanic populations of non-buoyant macroalgae in the high latitudes of the Southern Hemisphere

Marine biologists and biogeographers have long been puzzled by apparently non-dispersive coastal taxa that nonetheless have extensive transoceanic distributions. We here carried out a broad-scale phylogeographic study to test whether two widespread Southern Hemisphere species of non-buoyant littoral macroalgae are capable of long-distance dispersal. Samples were collected from along the coasts of southern Chile, New Zealand and several subAntarctic islands, with the focus on high latitude populations in the path of the Antarctic Circumpolar Current or West Wind Drift. We targeted two widespread littoral macroalgal species: the brown alga Adenocystisutricularis (Ectocarpales, Heterokontophyta) and the red alga Bostrychiaintricata (Ceramiales, Rhodophyta). Phylogenetic analyses were performed using partial mitochondrial (COI), chloroplast (rbcL) and ribosomal nuclear (LSU / 28S) DNA sequence data. Numerous deeply-divergent clades were resolved across all markers in each of the target species, but close phylogenetic relationships - even shared haplotypes - were observed among some populations separated by large oceanic distances. Despite not being particularly buoyant, both Adenocystisutricularis and Bostrychiaintricata thus show genetic signatures of recent dispersal across vast oceanic distances, presumably by attachment to floating substrata such as wood or buoyant macroalgae.This work was funded by New Zealand Marsden contract 07-UOO-099, Department of Zoology and University of Otago Research grants to JMW and CIF; a Shackleton Scholarship to CIF; an Allan Wilson Centre for Molecular Ecology and Evolution postdoctoral grant to CIF; Australian Antarctic Division AAS project #2914

On the boundary layer structure near a highly permeable porous interface

The method of matched asymptotic expansions is used to study the canonical problem of steady laminar flow through a narrow two-dimensional channel blocked by a tight-fitting finite-length highly permeable porous obstacle. We investigate the behaviour of the local flow close to the interface between the single-phase and porous regions (governed by the incompressible Navier--Stokes and Darcy flow equations, respectively). We solve for the flow in these inner regions in the limits of low and high Reynolds number, facilitating an understanding of the nature of the transition from Poiseuille to plug to Poiseuille flow in each of these limits. Significant analytical progress is made in the high-Reynolds-number limit, and we explore in detail the rich boundary layer structure that occurs. We derive general results for the interfacial stress and for the conditions that couple the flow in the outer regions away from the interface. We consider the three-dimensional generalization to unsteady laminar flow through and around a tight-fitting highly permeable cylindrical porous obstacle within a Hele-Shaw cell. For the high-Reynolds-number limit, we give the coupling conditions and interfacial stress in terms of the outer flow variables, allowing information from a nonlinear three-dimensional problem to be obtained by solving a linear two-dimensional problem. Finally, we illustrate the utility of our analysis by considering the specific example of time-dependent forced far-field flow in a Hele-Shaw cell containing a porous cylinder with a circular cross-section. We determine the internal stress within the porous obstacle, which is key for tissue engineering applications, and the interfacial stress on the boundary of the porous obstacle, which has applications to biofilm erosion. In the high-Reynolds-number limit, we demonstrate that the fluid inertia can result in the cylinder experiencing a time-independent net force, even when the far-field forcing is periodic with zero mean