3,338 research outputs found
Using drones and sirens to elicit avoidance behaviour in white rhinoceros as an anti-poaching tactic.
Poaching fuelled by international trade in horn caused the deaths of over 1000 African rhinoceros (Ceratotherium simum and Diceros bicornis) per year between 2013 and 2017. Deterrents, which act to establish avoidance behaviours in animals, have the potential to aid anti-poaching efforts by moving at-risk rhinos away from areas of danger (e.g. near perimeter fences). To evaluate the efficacy of deterrents, we exposed a population of southern white rhinos (C. simum simum) to acoustic- (honeybee, siren, turtle dove), olfactory- (chilli, sunflower), and drone-based stimuli on a game reserve in South Africa. We exposed rhinos to each stimulus up to four times. Stimuli were considered effective deterrents if they repeatedly elicited avoidance behaviour (locomotion away from the deterrent). Rhinos travelled significantly further in response to the siren than to the honeybee or turtle dove stimulus, and to low-altitude drone flights than to higher altitude flights. We found the drone to be superior at manipulating rhino movement than the siren owing to its longer transmission range and capability of pursuit. By contrast, the scent stimuli were ineffective at inciting avoidance behaviour. Our findings indicate that deterrents are a prospective low-cost and in situ method to manage rhino movement in game reserves
Detergent and sanitizer stresses decrease the thermal resistance of Enterobacter sakazakii in infant milk formula
Infant milk formula has been identified as a potential source of Enterobacter sakazakii. This bacterium can cause a severe form of neonatal meningitis and necrotizing entercolitis. This study determined the effect of acid, alkaline, chlorine and ethanol stresses on the thermal inactivation of E. sakazakii in infant milk formula. Stressed cells were mixed with reconstituted powdered infant milk formula (PIMF) at temperatures between 52 and 58°C for various time periods or mixed with PFMF prior to reconstitution with water at temperatures between 50 and 100°C. The D- and z-values of the cells were determined using linear regression analysis. Detergent and sanitizer stresses decreased the thermal resistance of E. sakazakii in powdered and reconstituted infant milk formula. The values for Z)- acid, alkaline, chlorine and ethanol stressed E. sakazakii at 52-58°C were 14.57-0.54, 12.07-0.37, 10.08-0.40 and 11.61-0.50 min, respectively. The values of alkaline, chlorine and ethanol stressed cells were significantly lower than those of unstressed cells. Only the z-value (4.4°C) of ethanol stressed E. sakazakii was significantly different than that of unstressed cells (4.12°C). Reconstitution at 60°C did not significantly reduce the number of pre-stressed E. sakazakii cells compared with unstressed control cells, whereas significant decreases were obtained at 70°C. Using water at 70°C during the preparation of reconstituted PIMF before feeding infants, may be a suitable and applicable means of reducing the risk of E. sakazakii in the formula. The results of this study may be of use to regulatory agencies, infant milk producers and infant caregivers to design heating processes to eliminate E. sakazakii that may be present in infant milk formula
Indoor Nature Interventions for Health and Wellbeing of Older Adults in Residential Settings: A Systematic Review.
This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this record.BACKGROUND AND OBJECTIVES: Having contact with nature can be beneficial for health and wellbeing, but many older adults face barriers with getting outdoors. We conducted a systematic review of quantitative studies on health and wellbeing impacts of indoor forms of nature (both real and simulated/artificial), for older adults in residential settings. RESEARCH DESIGN AND METHODS: Search terms relating to older adults and indoor nature were run in 13 scientific databases (MEDLINE, CINAHL, AgeLine, Environment Complete, AMED, PsychINFO, EMBASE, HMIC, PsychARTICLES, Global Health, Web of Knowledge, Dissertations and Theses Global, and ASSIA). We also pursued grey literature, global clinical trials registries, and a range of supplementary methods. RESULTS: Of 6,131 articles screened against eligibility criteria, 26 studies were accepted into the review, and were quality-appraised using the Effective Public Health Practice Project (EPHPP) tool. The participants were 930 adults aged over 60. Nature interventions and health/wellbeing outcomes were heterogeneous, which necessitated a narrative synthesis. The evidence base was generally weak, with 18 of 26 studies having a high risk of bias. However, several higher-quality studies found indoor gardening and horticulture programs were effective for cognition, psychological wellbeing, social outcomes, and life satisfaction. DISCUSSION AND IMPLICATIONS: There is inconsistent evidence that indoor nature exposures are beneficial for older care residents. We expect that successful interventions were, at least partly, facilitating social interaction, supporting feelings of autonomy/control, and promoting skill development, that is, factors not necessarily associated with nature per se. Higher-quality studies with improved reporting standards are needed to further elucidate these mechanisms.European CommissionNational Institute for Health Research (NIHR
What is the best way of delivering virtual nature for improving mood?: An experimental comparison of high definition TV, 360º video, and computer generated virtual reality
This is the final version. Available on open access from Elsevier via the DOI in this record. Exposure to ‘real’ nature can increase positive affect and decrease negative affect, but direct access is not always
possible, e.g. for people in health/care settings who often experience chronic boredom. In these settings ‘virtual’
forms of nature may also have mood-related benefits (e.g. reducing boredom) but it has been difficult to separate
effects of nature content from those of delivery mode. The present laboratory-based study explored whether
exposure to three different delivery modes of virtual nature could reduce negative affect (including boredom)
and/or increase positive affect. Adult volunteer participants (n = 96) took part in a boredom induction task (to
simulate the emotional state of many people in health/care settings) before being randomly assigned to view/
interact with a virtual underwater coral reef in one of three experimental conditions: (a) 2D video viewed on a
high-definition TV screen; (b) 3600 video VR (360-VR) viewed via a head mounted display (HMD); or (c)
interactive computer-generated VR (CG-VR), also viewed via a HMD and interacted with using a hand-held
controller. Visual and auditory content was closely matched across conditions with help from the BBC’s Blue
Planet II series team. Supporting predictions, virtual exposure to a coral reef reduced boredom and negative
affect and increased positive affect and nature connectedness. Although reductions in boredom and negative
affect were similar across all three conditions, CG-VR was associated with significantly greater improvements in
positive affect than TV, which were mediated by greater experienced presence and increases in nature
connectedness. Results improve our understanding of the importance of virtual nature delivery mode and will
inform studies in real care settings.EU Horizon 202
Dwarf Galaxy Formation Was Suppressed By Cosmic Reionization
A large number of faint galaxies, born less than a billion years after the
big bang, have recently been discovered. The fluctuations in the distribution
of these galaxies contributed to a scatter in the ionization fraction of cosmic
hydrogen on scales of tens of Mpc, as observed along the lines of sight to the
earliest known quasars. Theoretical simulations predict that the formation of
dwarf galaxies should have been suppressed after cosmic hydrogen was reionized,
leading to a drop in the cosmic star formation rate. Here we present evidence
for this suppression. We show that the post-reionization galaxies which
produced most of the ionizing radiation at a redshift z~5.5, must have had a
mass in excess of ~10^{10.6+/-0.4} solar masses or else the aforementioned
scatter would have been smaller than observed. This limiting mass is two orders
of magnitude larger than the galaxy mass that is thought to have dominated the
reionization of cosmic hydrogen (~10^8 solar masses). We predict that future
surveys with space-based infrared telescopes will detect a population of
smaller galaxies that reionized the Universe at an earlier time, prior to the
epoch of dwarf galaxy suppression.Comment: 19 pages, 3 figures. Accepted for publication in Nature; press
embargo until publishe
Mononuclear phenolate diamine zinc hydride complexes and their Reactions with CO2
[Image: see text] The synthesis, characterization, and zinc coordination chemistry of the three proligands 2-tert-butyl-4-[tert-butyl (1)/methoxy (2)/nitro (3)]-6-{[(2′-dimethylaminoethyl)methylamino]methyl}phenol are described. Each of the ligands was reacted with diethylzinc to yield zinc ethyl complexes 4–6; these complexes were subsequently reacted with phenylsilanol to yield zinc siloxide complexes 7–9. Finally, the zinc siloxide complexes were reacted with phenylsilane to produce the three new zinc hydride complexes 10–12. The new complexes 4–12 have been fully characterized by NMR spectroscopy, mass spectrometry, and elemental analyses. The structures of the zinc hydride complexes have been probed using VT-NMR spectroscopy and X-ray diffraction experiments. These data indicate that the complexes exhibit mononuclear structures at 298 K, both in the solid state and in solution (d(8)-toluene). At 203 K, the NMR signals broaden, consistent with an equilibrium between the mononuclear and dinuclear bis(μ-hydrido) complexes. All three zinc hydride complexes react rapidly and quantitatively with carbon dioxide, at 298 K and 1 bar of pressure over 20 min, to form the new zinc formate complexes 13–15. The zinc formate complexes have been analyzed by NMR spectroscopy and VT-NMR studies, which reveal a temperature-dependent monomer–dimer equilibrium that is dominated by the mononuclear species at 298 K
Aspects of structural health and condition monitoring of offshore wind turbines
Wind power has expanded significantly over the past years, although reliability of wind turbine systems, especially of offshore wind turbines, has been many times unsatisfactory in the past. Wind turbine failures are equivalent to crucial financial losses. Therefore, creating and applying strategies that improve the reliability of their components is important for a successful implementation of such systems. Structural health monitoring (SHM) addresses these problems through the monitoring of parameters indicative of the state of the structure examined. Condition monitoring (CM), on the other hand, can be seen as a specialized area of the SHM community that aims at damage detection of, particularly, rotating machinery. The paper is divided into two parts: in the first part, advanced signal processing and machine learning methods are discussed for SHM and CM on wind turbine gearbox and blade damage detection examples. In the second part, an initial exploration of supervisor control and data acquisition systems data of an offshore wind farm is presented, and data-driven approaches are proposed for detecting abnormal behaviour of wind turbines. It is shown that the advanced signal processing methods discussed are effective and that it is important to adopt these SHM strategies in the wind energy sector
Linear relations between N >= 4 supergravity and subleading-color SYM amplitudes
The IR divergences of supergravity amplitudes are less severe than those of
planar SYM amplitudes, and are comparable to those subleading-color SYM
amplitudes that are most subleading in the 1/N expansion, namely O(1/epsilon^L)
for L-loop amplitudes. We derive linear relations between one- and two-loop
four-point amplitudes and one-loop five-point amplitudes of N = 4, 5, and 6
supergravity and the most-subleading-color contributions of the analogous
amplitudes of N = 0, 1, and 2 SYM theory, extending earlier results for N = 8
supergravity amplitudes. Our work relies on linear relations between N >= 4
supergravity and planar SYM amplitudes that were recently derived using the
double-copy property of gravity, and color-kinematic duality of gauge theories.Comment: 21 pages, 1 figur
"It Makes You Feel That You Are There": Exploring the Acceptability of Virtual Reality Nature Environments for People with Memory Loss
This is the final version. Available on open access from MDPI via the DOI in this recordData Availability Statement:
The data presented in this study are available in the supplementary material.Aim: To report on the acceptability of virtual reality (VR) nature environments for people with memory loss at memory cafes, and explore the experiences and perceptions of carers and staff. Methods: A qualitative study was conducted between January and March 2019. Ten adults with memory loss, eight carers and six volunteer staff were recruited from two memory cafes, located in Cornwall, UK. There were 19 VR sessions which were audio recorded and all participants were interviewed at the end of the sessions. Framework analysis was used to identify patterns and themes in the data. Results: During the VR experience, participants were engaged to varying degrees, with engagement facilitated by the researcher, and in some cases, with the help of a carer. Participants responded positively to the nature scenes, finding them soothing and evoking memories. The VR experience was positive; many felt immersed in nature and saw it as an opportunity to 'go somewhere'. However, it was not always positive and for a few, it could be 'strange'. Participants reflected on their experience of the VR equipment, and volunteer staff and carers also shared their perceptions of VR for people with dementia in long-term care settings. Conclusions: The VR nature experience was an opportunity for people with memory loss to be immersed in nature and offered the potential to enhance their quality of life. Future work should build on lessons learned and continue to work with people with dementia in developing and implementing VR technology in long-term care settings.University of ExeterEuropean Union Horizon 2020National Institute for Health Research (NIHR
- …