Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Global Health ; 18(1): 39, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413844

RESUMO

Global threats to health and health security are growing. Fragile and failed states, armed groups, ungoverned spaces, outbreaks and potential unknown "Disease X" threats, antimicrobial resistance (AMR), hybrid and gray zone conflict all exacerbate complex medical emergencies. These growing threats increase preventable morbidity and mortality of the most vulnerable populations. In an effort to promote best practices, standardize responses, and prevent excess death and disability in these contexts, The Kofi Annan International Peacekeeping Training Centre (KAIPTC), with support from multiple international partners and a volunteer facilitator faculty, administered the pilot course for military and civilian health officers involved in U.N. peacekeeping missions entitled, "Comprehensive Medical Support in Complex Emergencies (CMSCE 19)." This brief review paper provides a description of the process in designing and delivering an interdisciplinary course for providers and decision makers responding to complex emergencies. We conclude with best practices and next steps for course evolution.


Assuntos
Emergências , Humanos
2.
J R Soc Interface ; 18(180): 20210264, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34255988

RESUMO

African elephants (Loxodonta africana) are sentient and intelligent animals that use a variety of vocalizations to greet, warn or communicate with each other. Their low-frequency rumbles propagate through the air as well as through the ground and the physical properties of both media cause differences in frequency filtering and propagation distances of the respective wave. However, it is not well understood how each mode contributes to the animals' abilities to detect these rumbles and extract behavioural or spatial information. In this study, we recorded seismic and co-generated acoustic rumbles in Kenya and compared their potential use to localize the vocalizing animal using the same multi-lateration algorithms. For our experimental set-up, seismic localization has higher accuracy than acoustic, and bimodal localization does not improve results. We conclude that seismic rumbles can be used to remotely monitor and even decipher elephant social interactions, presenting us with a tool for far-reaching, non-intrusive and surprisingly informative wildlife monitoring.


Assuntos
Elefantes , Acústica , Animais , Animais Selvagens , Reprodução , Vocalização Animal
3.
Proc Biol Sci ; 288(1953): 20210774, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34187196

RESUMO

African elephants (Loxodonta africana) use many sensory modes to gather information about their environment, including the detection of seismic, or ground-based, vibrations. Seismic information is known to include elephant-generated signals, but also potentially encompasses biotic cues that are commonly referred to as 'noise'. To investigate seismic information transfer in elephants beyond communication, here we tested the hypothesis that wild elephants detect and discriminate between seismic vibrations that differ in their noise types, whether elephant- or human-generated. We played three types of seismic vibrations to elephants: seismic recordings of elephants (elephant-generated), white noise (human-generated) and a combined track (elephant- and human-generated). We found evidence of both detection of seismic noise and discrimination between the two treatments containing human-generated noise. In particular, we found evidence of retreat behaviour, where seismic tracks with human-generated noise caused elephants to move further away from the trial location. We conclude that seismic noise are cues that contain biologically relevant information for elephants that they can associate with risk. This expands our understanding of how elephants use seismic information, with implications for elephant sensory ecology and conservation management.


Assuntos
Elefantes , Animais , Aprendizagem da Esquiva , Sinais (Psicologia) , Humanos , Ruído , Vibração
4.
Appl Sci (Basel) ; 10(21): 7655, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33680504

RESUMO

Transducers with a larger aperture size are desirable in ultrasound imaging to improve resolution and image quality. A coherent multi-transducer ultrasound imaging system (CoMTUS) enables an extended effective aperture through the coherent combination of multiple transducers. In this study, the discontinuous extended aperture created by CoMTUS and its performance for deep imaging and through layered media are investigated by both simulations and experiments. Typical image quality metrics-resolution, contrast and contrast-to-noise ratio-are evaluated and compared with a standard single probe imaging system. Results suggest that the image performance of CoMTUS depends on the relative spatial location of the arrays. The resulting effective aperture significantly improves resolution, while the separation between the arrays may degrade contrast. For a limited gap in the effective aperture (less than a few centimetres), CoMTUS provides benefits to image quality compared to the standard single probe imaging system. Overall, CoMTUS shows higher sensitivity and reduced loss of resolution with imaging depth. In general, CoMTUS imaging performance was unaffected when imaging through a layered medium with different speed of sound values and resolution improved up to 80% at large imaging depths.

5.
Chemosphere ; 217: 47-58, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30404048

RESUMO

In the context of decentralised brackish water treatment in development applications, the influence of water quality on membrane separation was investigated with real waters. High ionic strength (low net driving pressure) on fluoride (F) retention by nanofiltration (NF) and reverse osmosis (RO) was investigated over a wide pH range (2-12). Further, the influence of pH on the permeation of natural organic matter (NOM) fractions, in particular low molecular weight (LMW) neutrals, was elucidated. Natural and semi-natural waters from Tanzania with similar F concentrations of about 50 mg L-1 but varying NOM and inorganic carbon (IC) concentration were filtered with an NF and RO, namely NF270 and BW30. F retention by NF270 for the feed water with highest ionic strength and IC concentration was lower and attributed to charge screening. This parameter further reduced at high pH due to co-ions (F- and CO32-) interactions and combined (synergistic) effect of high salt concentration and pH on F. High NOM resulted in higher membrane zeta potential in comparison with low NOM natural water. However, there was no significant difference in F retention due to the fact that F retention enhancement was annulled by deposit formation on the membrane. The fraction of NOM found in NF/RO permeates was dominated by LMW neutrals. This was attributed to their size and uncharged nature, while their higher concentration at low pH remains unexplained. More humic substances (HS) of higher molecularity and aromaticity permeated the NF270 when compared with BW30, which can be explained with the different membrane molecular weight cut off (MWCO). The study highlights the complexity of treating tropical natural waters with elevated F and NOM concentrations. In order to develop appropriate membrane systems that will achieve optimal F and NOM removal, the influence of water quality parameters such as pH, NOM content, ionic strength and IC concentration requires understanding. Seasonal variation of water quality as well as operational fluctuations, which occur in particular when such treatment processes are operated with renewable energy, will require such challenges to be addressed. Further, given the high permeability of low molecular weight (LMW) organics significant permeate side fouling may be expected.


Assuntos
Fluoretos/isolamento & purificação , Compostos Orgânicos/isolamento & purificação , Purificação da Água/métodos , Substâncias Húmicas/análise , Membranas Artificiais , Peso Molecular , Compostos Orgânicos/química , Águas Salinas/química , Tanzânia , Ultrafiltração , Qualidade da Água
6.
J Acoust Soc Am ; 144(4): 2213, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30404511

RESUMO

Mammals use binaural or monaural (spectral) cues to localize acoustic sources. While the sensitivity of terrestrial mammals to changes in source elevation is relatively poor, the accuracy achieved by the odontocete cetaceans' biosonar is high, independently of where the source is. Binaural/spectral cues are unlikely to account for this remarkable skill. In this paper, bone-conducted sound in a dolphin's mandible is studied, investigating its possible contribution to sound localization. Experiments are conducted in a water tank by deploying, on the horizontal and median planes of the skull, ultrasound sources that emit synthetic clicks between 45 and 55 kHz. Elastic waves propagating through the mandible are measured at the pan bones and used to localize source positions via either binaural cues or a correlation-based full-waveform algorithm. Exploiting the full waveforms and, most importantly, reverberated coda, it is possible to enhance the accuracy of source localization in the vertical plane and achieve similar resolution of horizontal- vs vertical-plane sources. The results noted in this paper need to be substantiated by further experimental work, accounting for soft tissues and making sure that the data are correctly mediated to the internal ear. If confirmed, the results would favor the idea that dolphin's echolocation skills rely on the capability to analyze the coda of biosonar echoes.


Assuntos
Golfinhos Comuns/fisiologia , Ecolocação , Mandíbula/fisiologia , Animais , Som , Localização de Som
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...