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"Newton, Ian"
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migration ecology of birds
2008,2007,2010
This book presents an up-to-date, detailed and thorough review of the most fascinating ecological findings of bird migration. It deals with all aspects of this absorbing subject, including the problems of navigation and vagrancy, the timing and physiological control of migration, the factors that limit their populations, and more. Author, Ian Newton, reveals the extraordinary adaptability of birds to the variable and changing conditions across the globe, including current climate change. This adventurous book places emphasis on ecological aspects, which have received only scant attention in previous publications. Overall, the book provides the most thorough and in-depth appraisal of current information available, with abundant tables, maps and diagrams, and many new insights. Written in a clear and readable style, this book appeals not only to migration researchers in the field and Ornithologists, but to anyone with an interest in this fascinating subject. * Hot ecological aspects include: various types of bird movements, including dispersal and nomadism, and how they relate to food supplies and other external conditions * Contains numerous tables, maps and diagrams, a glossary, and a bibliography of more than 2,700 references* Written by an active researcher with a distinguished career in avian ecology, including migration research
Paneth Cell-Rich Regions Separated by a Cluster of Lgr5+ Cells Initiate Crypt Fission in the Intestinal Stem Cell Niche
by
Newton, Ian P.
,
Osborne, James M.
,
Langlands, Alistair J.
in
Age Factors
,
Animals
,
Biology and Life Sciences
2016
The crypts of the intestinal epithelium house the stem cells that ensure the continual renewal of the epithelial cells that line the intestinal tract. Crypt number increases by a process called crypt fission, the division of a single crypt into two daughter crypts. Fission drives normal tissue growth and maintenance. Correspondingly, it becomes less frequent in adulthood. Importantly, fission is reactivated to drive adenoma growth. The mechanisms governing fission are poorly understood. However, only by knowing how normal fission operates can cancer-associated changes be elucidated. We studied normal fission in tissue in three dimensions using high-resolution imaging and used intestinal organoids to identify underlying mechanisms. We discovered that both the number and relative position of Paneth cells and Lgr5+ cells are important for fission. Furthermore, the higher stiffness and increased adhesion of Paneth cells are involved in determining the site of fission. Formation of a cluster of Lgr5+ cells between at least two Paneth-cell-rich domains establishes the site for the upward invagination that initiates fission.
Journal Article
Loss of adenomatous polyposis coli function renders intestinal epithelial cells resistant to the cytokine IL-22
by
Vandereyken, Maud
,
Newton, Ian P.
,
Moraga, Ignacio
in
Adenomatous polyposis coli
,
Adenomatous Polyposis Coli - genetics
,
Adenomatous Polyposis Coli - metabolism
2019
Interleukin-22 (IL-22) is a critical immune defence cytokine that maintains intestinal homeostasis and promotes wound healing and tissue regeneration, which can support the growth of colorectal tumours. Mutations in the adenomatous polyposis coli gene (Apc) are a major driver of familial colorectal cancers (CRCs). How IL-22 contributes to APC-mediated tumorigenesis is poorly understood. To investigate IL-22 signalling in wild-type (WT) and APC-mutant cells, we performed RNA sequencing (RNAseq) of IL-22-treated murine small intestinal epithelial organoids. In WT epithelia, antimicrobial defence and cellular stress response pathways were most strongly induced by IL-22. Surprisingly, although IL-22 activates signal transducer and activator of transcription 3 (STAT3) in APC-mutant cells, STAT3 target genes were not induced. Our analyses revealed that ApcMin/Min cells are resistant to IL-22 due to reduced expression of the IL-22 receptor, and increased expression of inhibitors of STAT3, particularly histone deacetylases (HDACs). We further show that IL-22 increases DNA damage and genomic instability, which can accelerate cellular transition from heterozygosity (ApcMin/+) to homozygosity (ApcMin/Min) to drive tumour formation. Our data reveal an unexpected role for IL-22 in promoting early tumorigenesis while excluding a function for IL-22 in transformed epithelial cells.
Journal Article
Ecologically Justified Charisma: Preservation of Top Predators Delivers Biodiversity Conservation
by
Newton, Ian
,
Marchesi, Luigi
,
Pedrini, Paolo
in
Animal reproduction
,
Animal, plant and microbial ecology
,
Applied ecology
2006
1. Because of their popular appeal, top vertebrate predators have frequently been used as flagship or umbrella species to acquire financial support, raise environmental awareness and plan systems of protected areas. However, some have claimed that the utilization of charismatic predators may divert a disproportionate amount of funding to a few glamorous species without delivering broader biodiversity benefits, an accusation aggravated by the fact that the conservation of top predators is often complex, difficult and expensive. Therefore, tests are needed of whether apex predators may be employed to achieve ecosystem-level targets. 2. To test such a hypothesis, we compared the biodiversity values recorded at the breeding sites of six raptor species, differing widely in diet and habitat associations, with those observed at three types of control locations, (i) sites randomly chosen in comparable habitat, (ii) breeding sites of a randomly selected bird species of lower trophic level and (iii) breeding sites of a lower trophic level species with specialized ecological requirements. Biodiversity was measured as the richness and evenness of bird, butterfly and tree species. 3. Biodiversity levels were consistently higher at sites occupied by top predators than at any of the three types of control sites. Furthermore, sites occupied by top predators also held greater densities of individual birds and butterflies (all species combined) than control sites. 4. In a reserve-selection simulation exercise, networks of protected sites constructed on the basis of top predators were more efficient than networks based on lower trophic level species, enabling higher biodiversity coverage to be achieved with a smaller number of reserves. 5. Synthesis and applications. Our results provide evidence of a link between the strategic utilization of top predatory species and ecosystem-level conservation. We suggest that, at least in some biological systems, conservation plans based on apex predators could be implemented to deliver broader biodiversity benefits.
Journal Article
Ultrasound mediated delivery of quantum dots from a proof of concept capsule endoscope to the gastrointestinal wall
by
Newton, Ian P.
,
Thanou, Maya
,
Cox, Benjamin F.
in
639/166/985
,
692/700/565
,
692/700/565/1436/152
2021
Biologic drugs, defined as therapeutic agents produced from or containing components of a living organism, are of growing importance to the pharmaceutical industry. Though oral delivery of medicine is convenient, biologics require invasive injections because of their poor bioavailability via oral routes. Delivery of biologics to the small intestine using electronic delivery with devices that are similar to capsule endoscopes is a promising means of overcoming this limitation and does not require reformulation of the therapeutic agent. The efficacy of such capsule devices for drug delivery could be further improved by increasing the permeability of the intestinal tract lining with an integrated ultrasound transducer to increase uptake. This paper describes a novel proof of concept capsule device capable of electronic application of focused ultrasound and delivery of therapeutic agents. Fluorescent markers, which were chosen as a model drug, were used to demonstrate in vivo delivery in the porcine small intestine with this capsule. We show that the fluorescent markers can penetrate the mucus layer of the small intestine at low acoustic powers when combining microbubbles with focused ultrasound during in vivo experiments using porcine models. This study illustrates how such a device could be potentially used for gastrointestinal drug delivery and the challenges to be overcome before focused ultrasound and microbubbles could be used with this device for the oral delivery of biologic therapeutics.
Journal Article
Occupancy as a Measure of Territory Quality
2003
1. Territory quality may affect individual fitness and contribute to density-dependent reproduction, with repercussions on population regulation. We investigated the probable causes and population consequences of spatio-temporal variations in territory quality, measured by occupancy, in eight black kite Milvus migrans Boddaert populations, one of them studied for 10 years (Lake Lugano) and the rest for 4-5 years. 2. Over a period of years, the occupation rate of territories varied from a random pattern. Some territories were preferred while others were avoided. On return from migration, males and females settled earlier on high-occupancy territories. 3. The positive association between territory occupancy and breeding performance held in all years of study at Lake Lugano, and in six of seven tested populations. As a result, high-occupancy territories contributed most of the young produced by each population. 4. The occupation rate of the overall 225 territories was related positively to food availability and negatively to mortality risk, measured as proximity to the nearest eagle owl Bubo bubo Linnaeus nest. 5. At the population level, spatial variation in mean occupancy was positively correlated with spatial variation in mean productivity, suggesting that mean occupancy could be used as a measure of overall habitat quality and population performance. 6. In the Lake Lugano area, a higher proportion of low quality territories was occupied in years of higher density and annual productivity was related negatively to its coefficient of variation. However, annual productivity was not related significantly to the proportion of low quality territories occupied, so support for the theory of site-dependent population regulation was only partial. 7. In a review of 22 studies of territory occupancy in 17 species, occupancy always deviated from a random pattern in species in which it was tested and was always correlated with productivity and/or with some other measure of territory quality. Our results confirm the importance of prioritizing conservation of high quality territories. Occupancy may be a reliable method of quality assessment, especially for populations in which not all territories are always occupied, or for species in which checking occupancy is easier than finding nests.
Journal Article
Acoustic Sensing and Ultrasonic Drug Delivery in Multimodal Theranostic Capsule Endoscopy
by
Al-Rawhani, Mohammed
,
Cochran, Sandy
,
Näthke, Inke
in
acoustic sensing
,
Capsule Endoscopy
,
Diagnosis, Computer-Assisted
2017
Video capsule endoscopy (VCE) is now a clinically accepted diagnostic modality in which miniaturized technology, an on-board power supply and wireless telemetry stand as technological foundations for other capsule endoscopy (CE) devices. However, VCE does not provide therapeutic functionality, and research towards therapeutic CE (TCE) has been limited. In this paper, a route towards viable TCE is proposed, based on multiple CE devices including important acoustic sensing and drug delivery components. In this approach, an initial multimodal diagnostic device with high-frequency quantitative microultrasound that complements video imaging allows surface and subsurface visualization and computer-assisted diagnosis. Using focused ultrasound (US) to mark sites of pathology with exogenous fluorescent agents permits follow-up with another device to provide therapy. This is based on an US-mediated targeted drug delivery system with fluorescence imaging guidance. An additional device may then be utilized for treatment verification and monitoring, exploiting the minimally invasive nature of CE. While such a theranostic patient pathway for gastrointestinal treatment is presently incomplete, the description in this paper of previous research and work under way to realize further components for the proposed pathway suggests it is feasible and provides a framework around which to structure further work.
Journal Article
The prediction of swarming in honeybee colonies using vibrational spectra
by
Le Conte, Yves
,
Ramsey, Michael-Thomas
,
Newton, Michael Ian
in
631/158/1745
,
631/57
,
631/57/2266
2020
In this work, we disclose a non-invasive method for the monitoring and predicting of the swarming process within honeybee colonies, using vibro-acoustic information. Two machine learning algorithms are presented for the prediction of swarming, based on vibration data recorded using accelerometers placed in the heart of honeybee hives. Both algorithms successfully discriminate between colonies intending and not intending to swarm with a high degree of accuracy, over 90% for each method, with successful swarming prediction up to 30 days prior to the event. We show that instantaneous vibrational spectra predict the swarming within the swarming season only, and that this limitation can be lifted provided that the history of the evolution of the spectra is accounted for. We also disclose queen toots and quacks, showing statistics of the occurrence of queen pipes over the entire swarming season. From this we were able to determine that (1) tooting always precedes quacking, (2) under natural conditions there is a 4 to 7 day period without queen tooting following the exit of the primary swarm, and (3) human intervention, such as queen clipping and the opening of a hive, causes strong interferences with important mechanisms for the prevention of simultaneous rival queen emergence.
Journal Article
Dispersal
2018
Population density around the natal site is often invoked as an explanation for variation in dispersal distance, with the expectation that competition for limiting resources, coupled with increased intra-specific aggression at high densities, should drive changes in dispersal distances. However, tests of the density-dependent dispersal hypothesis in long-lived vertebrates have yielded mixed results. Furthermore, conclusions from dispersal studies may depend on the spatial and temporal scales at which density and dispersal patterns are examined, yet multi-scale studies of dispersal are rare. Here, we present the findings of a long-term study examining factors influencing natal dispersal distances for the non-migratory population of Peregrine Falcons (Falco peregrinus) in the British Isles across distinct spatial and temporal scales. Our smallest scale study included Peregrines ringed as nestlings and subsequently recaptured alive in south Scotland–north England, an area that was intensively studied during the time periods 1974–1982 and 2002–2016. Second, we examined dispersal patterns of birds ringed as nestlings in south Scotland–north England, but subsequently recaptured alive or recovered dead anywhere in the British Isles. Finally, we examined the natal dispersal patterns for Peregrines ringed and recaptured or recovered anywhere in the British Isles from 1964 to 2016. Consistent with prior findings, females dispersed farther than males across all scales. However, the patterns of dispersal were strongly scale dependent. Specifically, we found a lack of a discernible relationship between index of density and dispersal distance in the limited study area, but when region-wide recaptures and recoveries were included in the analyses, a negative relationship was revealed. Our results suggest that conclusions of dispersal studies may be scale dependent, highlighting the importance of spatial and temporal scales in examining and interpreting the relationship between population density and dispersal patterns.
Journal Article
Diclofenac Poisoning as a Cause of Vulture Population Declines across the Indian Subcontinent
by
Pain, Deborah J.
,
Shultz, Susanne
,
Gilbert, Martin
in
Animal, plant and microbial ecology
,
Applied ecology
,
Aves
2004
1. Rapid population declines of the vultures Gyps bengalensis, Gyps indicus and Gyps tenuirostris have recently been observed in India and Pakistan, continuing at least up to 2003. Surveys indicate annual rates of decline of 22-50% for G. bengalensis and G. indicus during 2000-03. Previous studies in Pakistan have shown that the non-steroidal anti-inflammatory drug diclofenac causes renal failure and is lethal to G. bengalensis when it feeds on the carcass of a domestic animal that received a normal veterinary dose shortly before death. In Pakistan, diclofenac poisoning was found to be by far the most frequent cause of death. 2. A simulation model of vulture demography, described in this paper, demonstrated that the observed rates of population decline could be caused by contamination with a lethal level of diclofenac in a small proportion (between 1: 130 and 1: 760) of ungulate carcasses available to vultures. 3. Proportions of adult and subadult vultures found dead or dying in the wild that had signs of diclofenac poisoning were similar to the proportions of deaths expected from the model if the observed population decline was due entirely to diclofenac poisoning. The proportion of the excess mortality required to cause the observed population declines that could be attributable to diclofenac was estimated to be between 71% and 100%, depending on model assumptions. However, across all or most of the plausible range of assumed values for adult survival, the upper 95% confidence limit for the proportion of excess mortality due to diclofenac was 100%. Hence, available data are consistent with diclofenac poisoning being at least the major cause, and possibly the only cause, of rapid population declines of Gyps vultures across the Indian subcontinent. 4. Synthesis and applications. We recommend that urgent action is taken in the range states of the three currently threatened vulture species to prevent the exposure of vultures to livestock carcasses contaminated with diclofenac. Research is also needed to identify alternative drugs that are effective in livestock and safe for vultures. Efforts should also be made to raise awareness, among veterinarians, pharmacists, livestock owners and the general public, of the problem of diclofenac contamination and the availability of safe alternatives. Captive holding and breeding of vultures until diclofenac is controlled is recommended as a precaution to ensure the long-term survival of the threatened species and to provide a stock of birds for future reintroduction programmes.
Journal Article