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1.
Childs Nerv Syst ; 39(12): 3593, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37498336

RESUMO

OBJECTIVE: Here we demonstrate via operative video the subtemporal extradural approach to a tumour in the cavernous sinus. METHODS: The extradural approach is performed here in a paediatric patient (a 15-year-old child) via a right extended pterional osteoplastic craniotomy with removal of the zygomatic arch. The operative microscope is introduced, and the dura is divided at the superior orbital fissure into endosteal and meningeal layers using a diamond knife. The middle cranial fossa floor is drilled flat to increase access, and the plane is further developed towards the cavernous sinus. The tumour is seen bulging from within the cavernous sinus, and the cavernous sinus is opened in the anteromedial triangle between cranial nerves Vi and Vii. After biopsy, the tumour is debulked with an ultrasonic aspirator. Doppler is used to identify the internal carotid artery and preserve it. The bone flap is replaced, and the wound is closed in layers in standard fashion. RESULTS: The patient recovered well and was discharged on post-operative day 3. Persistent sixth nerve palsy (present pre-operatively) was present; however, otherwise, there was good recovery from surgery. Good resection of tumour is demonstrated on post-operative MR imaging. CONCLUSIONS: This approach is uncommon but important as it enables extradural access to the cavernous sinus, minimising the complications associated with an intradural approach such as cortical injury. In this video, we also demonstrate the fundamental anatomy using annotation and cadaveric images to enhance understanding required for the neurosurgeon to successfully complete this approach. The patient consented to the procedure in the standard fashion.


Assuntos
Seio Cavernoso , Neoplasias Nasais , Adolescente , Humanos , Seio Cavernoso/diagnóstico por imagem , Seio Cavernoso/cirurgia , Fossa Craniana Média/diagnóstico por imagem , Fossa Craniana Média/cirurgia , Craniotomia/métodos , Procedimentos Neurocirúrgicos/métodos , Neoplasias Nasais/cirurgia
2.
Proc Biol Sci ; 289(1986): 20221692, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36350222

RESUMO

Air pollutants-such as nitrogen oxides, emitted in diesel exhaust, and ozone (O3)-disrupt interactions between plants, the insect herbivore pests that feed upon them and natural enemies of those herbivores (e.g. parasitoids). Using eight field-based rings that emit regulated quantities of diesel exhaust and O3, we investigated how both pollutants, individually and in combination, altered the attraction and parasitism rate of a specialist parasitoid (Diaeretiella rapae) on aphid-infested and un-infested Brassica napus plants. Individual effects of O3 decreased D. rapae abundance and emergence by 37% and 55%, respectively, compared with ambient (control) conditions. When O3 and diesel exhaust were emitted concomitantly, D. rapae abundance and emergence increased by 79% and 181%, respectively, relative to control conditions. This attraction response occurred regardless of whether plants were infested with aphids and was associated with an increase in the concentration of aliphatic glucosinolates, especially gluconapin (3-butenyl-glucosinolate), within B. napus leaves. Plant defensive responses and their ability to attract natural aphid enemies may be beneficially impacted by pollution exposure. These results demonstrate the importance of incorporating multiple air pollutants when considering the effects of air pollution on plant-insect interactions.


Assuntos
Poluentes Atmosféricos , Afídeos , Animais , Interações Hospedeiro-Parasita , Emissões de Veículos , Glucosinolatos , Afídeos/fisiologia
3.
Acta Neurochir (Wien) ; 164(6): 1605-1614, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35426509

RESUMO

OBJECTIVE: Quantitative data on visual outcomes after trans-sphenoidal surgery is lacking in the literature. This study aims to address this by quantitatively assessing visual field outcomes after endoscopic trans-sphenoidal pituitary adenectomy using the capabilities of modern semi-automated kinetic perimetry. METHODS: Visual field area (deg2) calculated on perimetry performed before and after surgery was statistically analysed. Functional improvement was assessed against UK driving standards. RESULTS: Sixty-four patients (128 eyes) were analysed (May 2016-Nov 2019). I4e and I3e isopter area significantly increased after surgery (p < 0.0001). Of eyes with pre-operative deficits: 80.7% improved and 7.9% worsened; the median amount of improvement was 60% (IQR 6-246%). Median increase in I4e isopter was 2213deg2 (IQR 595-4271deg2) and in I3e isopter 1034 deg2 (IQR 180-2001 deg2). Thirteen out of fifteen (87%) patients with III4e data regained driving eligibility after surgery. Age and extent of resection (EOR) did not correlate with visual improvement. Better pre-operative visual field area correlated with a better post-operative area (p < 0.0001). However, the rate of improvement in the visual field area increased with poorer pre-operative vision (p < 0.0001). CONCLUSIONS: A median visual field improvement of 60% may be expected in over 80% of patients. Functionally, a significant proportion of patients can expect to regain driving eligibility. EOR did not impact on visual recovery. When the primary goal of surgery is alleviating visual impairment, optic apparatus decompression without the aim for gross total resection appears a valid strategy. Patients with the worst pre-operative visual field often experience the greatest improvement, and therefore, poor pre-operative vision alone should not preclude surgical intervention.


Assuntos
Testes de Campo Visual , Campos Visuais , Endoscopia , Olho , Humanos , Hipófise
4.
Stem Cells ; 38(10): 1216-1228, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32598085

RESUMO

Stem cells (SCs) are unique cells that have an inherent ability to self-renew or differentiate. Both fate decisions are strongly regulated at the molecular level via intricate signaling pathways. The regulation of signaling networks promoting self-renewal or differentiation was thought to be largely governed by the action of transcription factors. However, small noncoding RNAs (ncRNAs), such as vault RNAs, and their post-transcriptional modifications (the epitranscriptome) have emerged as additional regulatory layers with essential roles in SC fate decisions. RNA post-transcriptional modifications often modulate RNA stability, splicing, processing, recognition, and translation. Furthermore, modifications on small ncRNAs allow for dual regulation of RNA activity, at both the level of biogenesis and RNA-mediated actions. RNA post-transcriptional modifications act through structural alterations and specialized RNA-binding proteins (RBPs) called writers, readers, and erasers. It is through SC-context RBPs that the epitranscriptome coordinates specific functional roles. Small ncRNA post-transcriptional modifications are today exploited by different mechanisms to facilitate SC translational studies. One mechanism readily being studied is identifying how SC-specific RBPs of small ncRNAs regulate fate decisions. Another common practice of using the epitranscriptome for regenerative applications is using naturally occurring post-transcriptional modifications on synthetic RNA to generate induced pluripotent SCs. Here, we review exciting insights into how small ncRNA post-transcriptional modifications control SC fate decisions in development and disease. We hope, by illustrating how essential the epitranscriptome and their associated proteome are in SCs, they would be considered as novel tools to propagate SCs for regenerative medicine.


Assuntos
Pequeno RNA não Traduzido/genética , Células-Tronco/metabolismo , Transcriptoma/genética , Animais , Epigênese Genética , Humanos , Células-Tronco Neoplásicas/metabolismo , Pequeno RNA não Traduzido/metabolismo , Proteínas de Ligação a RNA/metabolismo
5.
Childs Nerv Syst ; 36(9): 1977-1983, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32095868

RESUMO

BACKGROUND: Selective dorsal rhizotomy (SDR) is widely accepted as an effective procedure for management of lower limb spasticity in children with cerebral palsy. However, effects of the procedure on quality of life are not widely reported and less so using a structured and validated quality of life tool such as Cerebral Palsy Quality of Life Questionnaire (CPQoL). Here, we present complete data for CPQoL outcomes for SDR patients operated in a single institution at 2 years follow-up. METHODS: Patients were operated over a 5-year period by the same surgeon using the same technique in a single institution. CPQoL questionnaires were completed by patients and families pre-operatively and at 6 months, 1 year and 2 years post-operatively. Data was collected prospectively. RESULTS: A total of 78 patients (58 male, 20 female), age range 2.6-13.8 years (median 6.33) were included whom underwent SDR between October 2012-November 2017. All had complete follow-up up to 2 years post-procedure (most recent November 2019). Four patients were excluded due to incomplete follow-up data. Statistically significant improvement was seen across five out of seven CPQoL domains and this was sustained to 2 years post-SDR. CONCLUSIONS: We demonstrate using a validated Quality of Life Tool that SDR has a beneficial effect on the quality of life for patients with cerebral palsy at this length of follow-up.


Assuntos
Paralisia Cerebral , Qualidade de Vida , Adolescente , Paralisia Cerebral/complicações , Paralisia Cerebral/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Medidas de Resultados Relatados pelo Paciente , Rizotomia , Inquéritos e Questionários , Resultado do Tratamento
6.
Childs Nerv Syst ; 36(6): 1295-1299, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32219525

RESUMO

INTRODUCTION: We describe our technique of using reverse frontal bone graft for FOAR for patients with metopic or coronal synostosis and present our complications using the Leeds classification system for complications in craniosynostosis surgery. METHODS: Since April 2015, seventeen patients have been operated using this technique. We perform a frontal bone graft that is then reversed, and supraorbital margins are drilled out. The orbital bar is then removed and drilled down to make bone dust and on-lay bone grafts which are then used to fill gaps on exposed dura and fill in around the temporal region. RESULTS: All 17 patients who underwent this technique have good cosmetic results. We report 5 (29%) complications and 8 (47%) blood transfusions (7 exposures, 1 cell salvage).


Assuntos
Craniossinostoses , Procedimentos de Cirurgia Plástica , Transplante Ósseo , Craniossinostoses/diagnóstico por imagem , Craniossinostoses/cirurgia , Osso Frontal/diagnóstico por imagem , Osso Frontal/cirurgia , Humanos , Lactente , Órbita/diagnóstico por imagem , Órbita/cirurgia
7.
J Anim Ecol ; 87(5): 1475-1483, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29700820

RESUMO

Animal mutualisms, which involve beneficial interactions between individuals of different species, are common in nature. Insect-insect mutualism, for example, is widely regarded as a keystone ecological interaction. Some mutualisms are anticipated to be modified by climate change, but the focus has largely been on plant-microbe and plant-animal mutualisms rather than those between animals. Ant-aphid mutualisms, whereby ants tend aphids to harvest their honeydew excretions and, in return, provide protection for the aphids, are widespread. The mutualism is heavily influenced by the quality and quantity of honeydew produced by aphids, which is directly affected by host plant quality. As predicted increases in concentrations of atmospheric carbon dioxide (eCO2 ) are widely reported to affect plant nutritional chemistry, this may also alter honeydew quality and hence the nature of ant-aphid mutualisms. Using glasshouse chambers and field-based open-top chambers, we determined the effect of eCO2 on the growth and nutritional quality (foliar amino acids) of lucerne (Medicago sativa). We determined how cowpea aphid (Aphis craccivora) populations and honeydew production were impacted when feeding on such plants and how this affected the tending behaviour of ants (Iridomyrmex sp.). eCO2 stimulated plant growth but decreased concentrations of foliar amino acids by 29% and 14% on aphid-infested plants and aphid-free plants, respectively. Despite the deterioration in host plant quality under eCO2 , aphids maintained performance and populations were unchanged by eCO2 . Aphids induced higher concentrations of amino acids (glutamine, asparagine, glutamic acid and aspartic acid) important for endosymbiont-mediated synthesis of essential amino acids. Aphids feeding under eCO2 also produced over three times more honeydew than aphids feeding under ambient CO2 , suggesting they were imbibing more phloem sap at eCO2 . The frequency of ant tending of aphids more than doubled in response to eCO2 . To our knowledge, this is the first study to demonstrate the effects of atmospheric change on an ant-aphid mutualism. In particular, these results highlight how impending changes to concentrations of atmospheric CO2 may alter mutualistic behaviour between animals. These could include positive impacts, as reported here, shifts from mutualism to antagonism, partner switches and mutualism abandonment.


Assuntos
Formigas , Afídeos , Animais , Dióxido de Carbono , Plantas , Simbiose
8.
BMC Ecol ; 18(1): 53, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30514265

RESUMO

BACKGROUND: Grasses are hyper-accumulators of silicon (Si) and often up-regulate Si following herbivory. Positive correlations exist between Si and plant water content, yet the extent to which Si uptake responses can be mediated by changes in soil water availability has rarely been studied and never, to our knowledge, under field conditions. We used field-based rain-exclusion shelters to investigate how simulated grazing (shoot clipping) and altered rainfall patterns (drought and elevated precipitation, representing 50% and 150% of ambient precipitation levels, respectively) affected initial patterns of root- and shoot-Si uptake in a native Australian grass (Microlaena stipoides) in Si-supplemented and untreated soils. RESULTS: Si supplementation increased soil water retention under ambient and elevated precipitation but not under drought, although this had little effect on Si uptake and growth (tiller numbers or root biomass) of M. stipoides. Changes in rainfall patterns and clipping had strong individual effects on plant growth and Si uptake and storage, whereby clipping increased Si uptake by M. stipoides under all rainfall treatments but to the greatest extent under elevated precipitation. Moreover, above-ground-below-ground Si distribution only changed following elevated precipitation by decreasing the ratio of root:shoot Si concentrations. CONCLUSIONS: Results highlight the importance of soil water availability for Si uptake and suggest a role for both active and passive Si transport mechanisms. Such manipulative field studies may provide a more realistic insight into how grasses initially respond to herbivory in terms of Si-based defence under different environmental conditions.


Assuntos
Secas , Cadeia Alimentar , Poaceae/metabolismo , Silício/metabolismo , Animais , Bovinos/fisiologia , Comportamento Alimentar , Pradaria , New South Wales , Chuva , Solo/química
9.
Acta Neurochir (Wien) ; 160(1): 39-47, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29063272

RESUMO

BACKGROUND: The object of this study was to assess whether increasing operative experience results in greater endoscopic trans-sphenoidal resection of pituitary macroadenomas and lower complications. METHODS: A retrospective single institution cohort study was performed. Subjects underwent endoscopic trans-sphenoidal resection of pituitary macroadenoma between July 2009 and July 2016 by three neurosurgeons. Following data collection, statistical analysis compared percentage of tumor resection and length of hospital stay (LOS) with experience. Complications including CSF leak are reported. RESULTS: In total, 142 patients (87 male, 55 female) mean age 55.1 were included. Surgeon 1 performed 106 cases; surgeon 2 performed 23 cases; and surgeon 3 performed 13 cases. Mean pre-operative tumor volumes were 8.18 cm3, 6.52 cm3, and 3.47 cm3 and post-operative volumes were 2.21, 1.74, and 1.93 cm3 for surgeons 1, 2, and 3, respectively. Respective percentage resections were 74.3, 77.2, and 52.1%. Analysis demonstrated no difference in tumor resection with increasing experience for all three surgeons (p = 0.11, p = 0.17, and p = 0.26). Tumor consistency and cavernous sinus involvement did not appear to affect tumor resection. Mean LOS was 5 days, 4 days, and 3 days, respectively, with no significant correlation with experience for all three surgeons. Intraoperative CSF leak incidence was 19/106 (18%) for surgeon 1, 6/23(26%) for surgeon 2, and 2/13(15%) for surgeon 3. Primary closure rate was 96.3% and only three other complications occurred. CONCLUSIONS: This study demonstrates that in our institution there is no statistically significant learning curve for the endoscopic resection of pituitary macroadenoma. However, there is a trend of improvement in tumor resection with experience for one surgeon. These findings suggest that the surgeons in our institution were capable of performing this procedure effectively with a low complication rate since adoption of the endoscopic technique in 2009.


Assuntos
Adenoma/cirurgia , Endoscopia/educação , Neoplasias Hipofisárias/cirurgia , Seio Esfenoidal/cirurgia , Endoscopia/métodos , Feminino , Humanos , Curva de Aprendizado , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Carga Tumoral
10.
J Biol Chem ; 291(22): 11657-75, 2016 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-27013657

RESUMO

Adrenomedullin (AM) is a peptide hormone with numerous effects in the vascular systems. AM signals through the AM1 and AM2 receptors formed by the obligate heterodimerization of a G protein-coupled receptor, the calcitonin receptor-like receptor (CLR), and receptor activity-modifying proteins 2 and 3 (RAMP2 and RAMP3), respectively. These different CLR-RAMP interactions yield discrete receptor pharmacology and physiological effects. The effective design of therapeutics that target the individual AM receptors is dependent on understanding the molecular details of the effects of RAMPs on CLR. To understand the role of RAMP2 and -3 on the activation and conformation of the CLR subunit of AM receptors, we mutated 68 individual amino acids in the juxtamembrane region of CLR, a key region for activation of AM receptors, and determined the effects on cAMP signaling. Sixteen CLR mutations had differential effects between the AM1 and AM2 receptors. Accompanying this, independent molecular modeling of the full-length AM-bound AM1 and AM2 receptors predicted differences in the binding pocket and differences in the electrostatic potential of the two AM receptors. Druggability analysis indicated unique features that could be used to develop selective small molecule ligands for each receptor. The interaction of RAMP2 or RAMP3 with CLR induces conformational variation in the juxtamembrane region, yielding distinct binding pockets, probably via an allosteric mechanism. These subtype-specific differences have implications for the design of therapeutics aimed at specific AM receptors and for understanding the mechanisms by which accessory proteins affect G protein-coupled receptor function.


Assuntos
Adrenomedulina/metabolismo , Proteína Semelhante a Receptor de Calcitonina/metabolismo , Proteína 2 Modificadora da Atividade de Receptores/metabolismo , Proteína 3 Modificadora da Atividade de Receptores/metabolismo , Adrenomedulina/genética , Sequência de Aminoácidos , Proteína Semelhante a Receptor de Calcitonina/química , Proteína Semelhante a Receptor de Calcitonina/genética , Cristalografia por Raios X , Humanos , Modelos Moleculares , Ligação Proteica , Proteína 2 Modificadora da Atividade de Receptores/química , Proteína 2 Modificadora da Atividade de Receptores/genética , Proteína 3 Modificadora da Atividade de Receptores/química , Proteína 3 Modificadora da Atividade de Receptores/genética , Receptores de Adrenomedulina/química , Receptores de Adrenomedulina/genética , Receptores de Adrenomedulina/metabolismo , Alinhamento de Sequência
11.
Biol Lett ; 13(3)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28298594

RESUMO

Silicon (Si) has important functional roles in plants, including resistance against herbivores. Environmental change, such as increasing atmospheric concentrations of CO2, may alter allocation to Si defences in grasses, potentially changing the feeding behaviour and performance of herbivores, which may in turn impact on higher trophic groups. Using Si-treated and untreated grasses (Phalaris aquatica) maintained under ambient (400 ppm) and elevated (640 and 800 ppm) CO2 concentrations, we show that Si reduced feeding by crickets (Acheta domesticus), resulting in smaller body mass. This, in turn, reduced predatory behaviour by praying mantids (Tenodera sinensis), which consequently performed worse. Despite elevated CO2 decreasing Si concentrations in P. aquatica, this reduction was not large enough to affect the feeding behaviour of crickets or their predator. Our results suggest that Si-based defences in plants have adverse impacts on both primary and secondary trophic taxa, and these are not likely to decline under future climate change scenarios.


Assuntos
Dióxido de Carbono/farmacologia , Gryllidae/fisiologia , Mantódeos/fisiologia , Phalaris/química , Silício/análise , Animais , Atmosfera/química , Peso Corporal , Comportamento Alimentar , Cadeia Alimentar , Phalaris/efeitos dos fármacos , Comportamento Predatório
12.
J Exp Bot ; 66(2): 613-23, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25403916

RESUMO

Changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. This study investigated how mechanically simulated root herbivory of lucerne (Medicago sativa) before and after aphid infestation affected the pea aphid (Acyrthosiphon pisum) under elevated temperature (eT) and carbon dioxide concentrations (eCO2). eT increased plant height and biomass, and eCO2 decreased root C:N. Foliar amino acid concentrations and aphid numbers increased in response to eCO2, but only at ambient temperatures, demonstrating the ability of eT to negate the effects of eCO2. Root damage reduced aboveground biomass, height, and root %N, and increased root %C and C:N, most probably via decreased biological nitrogen fixation. Total foliar amino acid concentrations and aphid colonization success were higher in plants with roots cut early (before aphid arrival) than those with roots cut late (after aphid arrival); however, this effect was counteracted by eT. These results demonstrate the importance of amino acid concentrations for aphids and identify individual amino acids as being potential factors underpinning aphid responses to eT, eCO2, and root damage in lucerne. Incorporating trophic complexity and multiple climatic factors into plant-herbivore studies enables greater insight into how plants and insects will interact in the future, with implications for sustainable pest control and future crop security.


Assuntos
Ar , Aminoácidos/farmacologia , Afídeos/fisiologia , Dióxido de Carbono/farmacologia , Herbivoria/efeitos dos fármacos , Raízes de Plantas/parasitologia , Temperatura , Animais , Afídeos/efeitos dos fármacos , Biomassa , Medicago sativa/parasitologia , Modelos Biológicos
14.
Nat Commun ; 15(1): 5447, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992007

RESUMO

Air pollution has the potential to disrupt ecologically- and economically-beneficial services provided by invertebrates, including pollination and natural pest regulation. To effectively predict and mitigate this disruption requires an understanding of how the impacts of air pollution vary between invertebrate groups. Here we conduct a global meta-analysis of 120 publications comparing the performance of different invertebrate functional groups in unpolluted and polluted atmospheres. We focus on the pollutants ozone, nitrogen oxides, sulfur dioxide and particulate matter. We show that beneficial invertebrate performance is reduced by air pollution, whereas the performance of plant pest invertebrates is not significantly affected. Ozone pollution has the most detrimental impacts, and these occur at concentrations below national and international air quality standards. Changes in invertebrate performance are not dependent on air pollutant concentrations, indicating that even low levels of pollution are damaging. Predicted increases in tropospheric ozone could result in unintended consequences to global invertebrate populations and their valuable ecological services.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Invertebrados , Ozônio , Material Particulado , Animais , Poluição do Ar/efeitos adversos , Invertebrados/efeitos dos fármacos , Ozônio/toxicidade , Ozônio/efeitos adversos , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/efeitos adversos , Material Particulado/efeitos adversos , Dióxido de Enxofre/toxicidade , Óxidos de Nitrogênio/toxicidade , Polinização
15.
MethodsX ; 12: 102635, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38454911

RESUMO

Air pollution is an escalating concern in the modern world, posing substantial threats to ecosystem processes. While the importance of comprehending the impact of pollutants on natural environments is evident, conducting rigorous field-based experiments presents formidable challenges. Elevating pollutant concentrations within open air environments in a controlled manner is complex. Nonetheless, such real-world experiments are invaluable for revealing the genuine influence of air pollutants on ecosystems and their functioning. Field-scale measurements have emerged as a pivotal avenue for advancing our understanding of the interactions between air pollutants and the natural world, providing unique insights into ecosystem dynamics, including critical processes like pollination and natural pest regulation. In atmospheric and ecological research, free-air exposure systems have proven effective in elevating carbon dioxide (CO2) and ozone (O3) concentrations, facilitating the exploration of their ecological consequences. Yet, nitrogen oxides (NOx), a class of pollutants with significant ecological and atmospheric relevance, have largely eluded field-based ecological investigations. This paper introduces the recently developed FADOE (Free-Air Diesel and Ozone Enrichment) platform, which allows the elevation of O3 and diesel exhaust (including NOx) within a field-scale context. Comprehensive information on the system's design, construction, and performance data from the 2023 summer season is presented.•Air pollution and ecosystem functioning•Elevated ozone and nitrogen oxides (NOx)•Free-air exposure systems for field scale measurements.

16.
Environ Pollut ; 336: 122336, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37595729

RESUMO

The critical ecological process of animal-mediated pollination is commonly facilitated by odour cues. These odours consist of volatile organic compounds (VOCs), often with short chemical lifetimes, which form the strong concentration gradients necessary for pollinating insects to locate a flower. Atmospheric oxidants, including ozone pollution, may react with and chemically alter these VOCs, impairing the ability of pollinators to locate a flower, and therefore the pollen and nectar on which they feed. However, there is limited mechanistic empirical evidence to explain these processes within an odour plume at temporal and spatial scales relevant to insect navigation and olfaction. We investigated the impact of ozone pollution and turbulent mixing on the fate of four model floral VOCs within odour plumes using a series of controlled experiments in a large wind tunnel. Average rates of chemical degradation of α-terpinene, ß-caryophyllene and 6-methyl-5-hepten-2-one were slightly faster than predicted by literature rate constants, but mostly within uncertainty bounds. Mixing reduced reaction rates by 8-10% in the first 2 m following release. Reaction rates also varied across the plumes, being fastest at plume edges where VOCs and ozone mixed most efficiently and slowest at plume centres. Honeybees were trained to learn a four VOC blend equivalent to the plume released at the wind tunnel source. When subsequently presented with an odour blend representative of that observed 6 m from the source at the centre of the plume, 52% of honeybees recognised the odour, decreasing to 38% at 12 m. When presented with the more degraded blend from the plume edge, recognition decreased to 32% and 10% at 6 and 12 m respectively. Our findings highlight a mechanism by which anthropogenic pollutants can disrupt the VOC cues used in plant-pollinator interactions, which likely impacts on other critical odour-mediated behaviours such as mate attraction.

18.
Front Microbiol ; 13: 851450, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35547145

RESUMO

Microbial communities are ubiquitous and carry an exceptionally broad metabolic capability. Upon environmental perturbation, microbes are also amongst the first natural responsive elements with perturbation-specific cues and markers. These communities are thereby uniquely positioned to inform on the status of environmental conditions. The advent of microbial omics has led to an unprecedented volume of complex microbiological data sets. Importantly, these data sets are rich in biological information with potential for predictive environmental classification and forecasting. However, the patterns in this information are often hidden amongst the inherent complexity of the data. There has been a continued rise in the development and adoption of machine learning (ML) and deep learning architectures for solving research challenges of this sort. Indeed, the interface between molecular microbial ecology and artificial intelligence (AI) appears to show considerable potential for significantly advancing environmental monitoring and management practices through their application. Here, we provide a primer for ML, highlight the notion of retaining biological sample information for supervised ML, discuss workflow considerations, and review the state of the art of the exciting, yet nascent, interdisciplinary field of ML-driven microbial ecology. Current limitations in this sphere of research are also addressed to frame a forward-looking perspective toward the realization of what we anticipate will become a pivotal toolkit for addressing environmental monitoring and management challenges in the years ahead.

19.
Sci Rep ; 12(1): 21030, 2022 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-36470936

RESUMO

Postural control research has focused on standing balance experiments on platforms moving with relatively large amplitudes (0.1-0.2 m). This study investigated balance strategies while standing on a platform moving 4 mm in anterior-posterior direction with frequency scaled linearly from 0.4 to 6 Hz. Platform motion and kinematic and kinetic information for nine healthy participants were recorded using motion capture and force plate systems. Coordination between hip, knee and ankle joint torque, and centre of mass (COM) and centre of pressure (COP) motion was quantified by vector coding. Significant main effect of platform frequency for knee-ankle and COP-COM phase relationship was observed (p = 0.023, p = 0.016). At frequencies below 2.11 and 2.34 Hz, ankle strategy was recruited. With ankle strategy, in-phase COP-COM motion with COP dominancy occurred at frequencies below 2.19 and 2.23 Hz during scaling up and down, respectively. As platform frequency passed these values, COM dominated over COP which was followed by anti-phase knee-ankle torque, called a knee strategy, and anti-phase motion between the COP and COM that allowed COP to regain dominance over COM. Collectively, we reveal knee strategy as a new and relevant strategy in real-life settings, and transition between ankle and knee strategies that underpinned transition between COP-COM relative motion.


Assuntos
Equilíbrio Postural , Postura , Humanos , Fenômenos Biomecânicos , Articulação do Tornozelo , Tornozelo
20.
Environ Pollut ; 297: 118847, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35063287

RESUMO

Common air pollutants, such as nitrogen oxides (NOx), emitted in diesel exhaust, and ozone (O3), have been implicated in the decline of pollinating insects. Reductionist laboratory assays, focused upon interactions between a narrow range of flowering plant and pollinator species, in combination with atmospheric chemistry models, indicate that such pollutants can chemically alter floral odors, disrupting the cues that foraging insects use to find and pollinate flowers. However, odor environments in nature are highly complex and pollination services are commonly provided by suites of insect species, each exhibiting different sensitivities to different floral odors. Therefore, the potential impacts of pollution-induced foraging disruption on both insect ecology, and the pollination services that insects provide, are currently unknown. We conducted in-situ field studies to investigate whether such pollutants could reduce pollinator foraging and as a result the pollination ecosystem service that those insects provide. Using free-air fumigation, we show that elevating diesel exhaust and O3, individually and in combination, to levels lower than is considered safe under current air quality standards, significantly reduced counts of locally-occurring wild and managed insect pollinators by 62-70% and their flower visits by 83-90%. These reductions were driven by changes in specific pollinator groups, including bees, flies, moths and butterflies, and coincided with significant reductions (14-31%) in three different metrics of pollination and yield of a self-fertile test plant. Quantifying such effects provides new insights into the impacts of human-induced air pollution on the natural ecosystem services upon which we depend.


Assuntos
Poluentes Atmosféricos , Borboletas , Animais , Abelhas , Ecossistema , Flores , Insetos , Polinização
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