Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
1.
Soc Sci Humanit Open ; 3(1): 100102, 2021.
Article in English | MEDLINE | ID: mdl-33889839

ABSTRACT

Top-down population modelling has gained applied prominence in public health, planning, and sustainability applications at the global scale. These top-down population modelling methods often rely on remote-sensing (RS) derived representation of the built-environment and settlements as key predictive covariates. While these RS-derived data, which are global in extent, have become more advanced and more available, gaps in spatial and temporal coverage remain. These gaps have prompted the interpolation of the built-environment and settlements, but the utility of such interpolated data in further population modelling applications has garnered little research. Thus, our objective was to determine the utility of modelled built-settlement extents in a top-down population modelling application. Here we take modelled global built-settlement extents between 2000 and 2012, created using a spatio-temporal disaggregation of observed settlement growth. We then demonstrate the applied utility of such annually modelled settlement data within the application of annually modelling population, using random forest informed dasymetric disaggregations, across 172 countries and a 13-year period. We demonstrate that the modelled built-settlement data are consistently the 2nd most important covariate in predicting population density, behind annual lights at night, across the globe and across the study period. Further, we demonstrate that this modelled built-settlement data often provides more information than current annually available RS-derived data and last observed built-settlement extents.

2.
Comput Environ Urban Syst ; 80: 101444, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32139952

ABSTRACT

Mapping urban features/human built-settlement extents at the annual time step has a wide variety of applications in demography, public health, sustainable development, and many other fields. Recently, while more multitemporal urban features/human built-settlement datasets have become available, issues still exist in remotely-sensed imagery due to spatial and temporal coverage, adverse atmospheric conditions, and expenses involved in producing such datasets. Remotely-sensed annual time-series of urban/built-settlement extents therefore do not yet exist and cover more than specific local areas or city-based regions. Moreover, while a few high-resolution global datasets of urban/built-settlement extents exist for key years, the observed date often deviates many years from the assigned one. These challenges make it difficult to increase temporal coverage while maintaining high fidelity in the spatial resolution. Here we describe an interpolative and flexible modelling framework for producing annual built-settlement extents. We use a combined technique of random forest and spatio-temporal dasymetric modelling with open source subnational data to produce annual 100 m × 100 m resolution binary built-settlement datasets in four test countries located in varying environmental and developmental contexts for test periods of five-year gaps. We find that in the majority of years, across all study areas, the model correctly identified between 85 and 99% of pixels that transition to built-settlement. Additionally, with few exceptions, the model substantially out performed a model that gave every pixel equal chance of transitioning to built-settlement in each year. This modelling framework shows strong promise for filling gaps in cross-sectional urban features/built-settlement datasets derived from remotely-sensed imagery, provides a base upon which to create urban future/built-settlement extent projections, and enables further exploration of the relationships between urban/built-settlement area and population dynamics.

4.
Pediatr Pulmonol ; 50(4): 327-32, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25408378

ABSTRACT

BACKGROUND: Evidence suggests infection is present in the lower airways of young children with cystic fibrosis (CF), even when clinically stable. Oropharyngeal samples (OPS) are typically used for airway surveillance in these children but have been shown to have low positive predictive values and low sensitivity in detecting lower airway infection when compared with the reference standard, bronchoalveolar lavage (BAL). METHODS: The aim of this study was to determine the prevalence of pathogens in lower airway samples detected as part of a pilot clinical BAL surveillance programme, in young children aged from one to six years old, and to ascertain if their detection resulted in a change in treatment. RESULTS: During the study 78 bronchoscopies were performed on 38 patients. The average age at the time of bronchoscopy was 2.7 years (range 0.3-7.0 year). A significant organism was detected in 58 (74.5%) BALs. Haemophilus influenzae was detected in 27 (34.6%) samples, 16 (20.5%) samples had Staphylococcus aureus, and nine (11.5%) had Pseudomonas aeruginosa. Change in treatment occurred after 46 (58.9%) BALs. CONCLUSIONS: This study suggests that, in young non-expectorating children with CF, routine surveillance bronchoscopy allows the detection of significant lower airway pathogens and provides the opportunity for targeted treatment of sub-clinical infection.


Subject(s)
Bronchoalveolar Lavage Fluid/microbiology , Cystic Fibrosis/microbiology , Bronchoscopy , Child , Child, Preschool , Female , Haemophilus influenzae/isolation & purification , Humans , Male , Pilot Projects , Population Surveillance , Pseudomonas aeruginosa/isolation & purification , Retrospective Studies , Staphylococcus aureus/isolation & purification
5.
Eur Respir J ; 44(2): 394-404, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24696116

ABSTRACT

Airway disease in cystic fibrosis (CF) is characterised by impaired mucociliary clearance, persistent bacterial infection and neutrophilic inflammation. Lipoxin A4 (LXA4) initiates the active resolution of inflammation and promotes airway surface hydration in CF models. 15-Lipoxygenase (LO) plays a central role in the "class switch" of eicosanoid mediator biosynthesis from leukotrienes to lipoxins, initiating the active resolution of inflammation. We hypothesised that defective eicosanoid mediator class switching contributes to the failure to resolve inflammation in CF lung disease. Using bronchoalveolar lavage (BAL) samples from 46 children with CF and 19 paediatric controls we demonstrate that the ratio of LXA4 to leukotriene B4 (LTB4) is depressed in CF BAL (p<0.01), even in the absence of infection (p<0.001). Furthermore, 15-LO2 transcripts were significantly less abundant in CF BAL samples (p<0.05). In control BAL, there were positive relationships between 15-LO2 transcript abundance and LXA4/LTB4 ratio (p=0.01, r=0.66) and with percentage macrophage composition of the BAL fluid (p<0.001, r=0.82), which were absent in CF. Impoverished 15-LO2 expression and depression of the LXA4/LTB4 ratio are observed in paediatric CF BAL. These observations provide mechanistic insights into the failure to resolve inflammation in the CF lung.


Subject(s)
Arachidonate 15-Lipoxygenase/metabolism , Cystic Fibrosis/blood , Leukotriene B4/chemistry , Lipoxins/chemistry , Anti-Bacterial Agents/therapeutic use , Bronchoalveolar Lavage Fluid/chemistry , Child , Child, Preschool , Cystic Fibrosis/metabolism , Cystic Fibrosis/physiopathology , Female , Humans , Inflammation , Leukotriene A4/chemistry , Longitudinal Studies , Lung/immunology , Lung/pathology , Lung Diseases/microbiology , Macrophages, Alveolar/metabolism , Male , Neutrophils/cytology , Neutrophils/metabolism
6.
Biotechnol Biofuels ; 2(1): 13, 2009 Jul 03.
Article in English | MEDLINE | ID: mdl-19575786

ABSTRACT

BACKGROUND: This work explores the potential contribution of bioenergy technologies to 60% and 80% carbon reductions in the UK energy system by 2050, by outlining the potential for accelerated technological development of bioenergy chains. The investigation was based on insights from MARKAL modelling, detailed literature reviews and expert consultations. Due to the number and complexity of bioenergy pathways and technologies in the model, three chains and two underpinning technologies were selected for detailed investigation: (1) lignocellulosic hydrolysis for the production of bioethanol, (2) gasification technologies for heat and power, (3) fast pyrolysis of biomass for bio-oil production, (4) biotechnological advances for second generation bioenergy crops, and (5) the development of agro-machinery for growing and harvesting bioenergy crops. Detailed literature searches and expert consultations (looking inter alia at research and development needs and economic projections) led to the development of an 'accelerated' dataset of modelling parameters for each of the selected bioenergy pathways, which were included in five different scenario runs with UK-MARKAL (MED). The results of the 'accelerated runs' were compared with a low-carbon (LC-Core) scenario, which assesses the cheapest way to decarbonise the energy sector. RESULTS: Bioenergy was deployed in larger quantities in the bioenergy accelerated technological development scenario compared with the LC-Core scenario. In the electricity sector, solid biomass was highly utilised for energy crop gasification, displacing some deployment of wind power, and nuclear and marine to a lesser extent. Solid biomass was also deployed for heat in the residential sector from 2040 in much higher quantities in the bioenergy accelerated technological development scenario compared with LC-Core. Although lignocellulosic ethanol increased, overall ethanol decreased in the transport sector in the bioenergy accelerated technological development scenario due to a reduction in ethanol produced from wheat. CONCLUSION: There is much potential for future deployment of bioenergy technologies to decarbonise the energy sector. However, future deployment is dependent on many different factors including investment and efforts towards research and development needs, carbon reduction targets and the ability to compete with other low carbon technologies as they become deployed. All bioenergy technologies should become increasingly more economically competitive with fossil-based technologies as feedstock costs and flexibility are reduced in line with technological advances.

7.
Thyroid ; 16(7): 691-5, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16889494

ABSTRACT

BACKGROUND: Management of a hyperthyroid patient unable to take oral or rectal medication is a difficult clinical problem. The need for an alternative parenteral route of antithyroid medication administration in thyrotoxic patients occurs in certain rare cases, such as emergent gastrointestinal surgery, bowel ileus or obstruction, or severe vomiting and diarrhea. We report a simple and successful protocol for the preparation and use of intravenous methimazole (MMI) for treatment of hyperthyroidism in patients intolerant of orally and rectally administered thionamides. METHODS: Five hundred milligrams of methimazole USP powder was reconstituted with pH-neutral 0.9% sodium chloride solution to a final volume of 50 mL using aseptic technique, then filtered through a 0.22-microm filter. MMI injection was administered as a slow intravenous push over 2 minutes and followed by a saline flush. CASES: A 76-year-old man, intolerant of oral and rectal medications because of an ileus and intractable diarrhea, who developed worsening thyrotoxicosis after an emergent spinal cord decompression, and a 42-year-old man with chronic liver disease and hyperthyroidism, requiring emergent exploratory laparotomy and maintenance of complete bowel rest because of persistent gastrointestinal bleeding were rendered euthyroid using intravenous MMI. CONCLUSION: Two cases of hyperthyroidism successfully treated with a preparation of intravenous MMI are described.


Subject(s)
Antithyroid Agents/administration & dosage , Hyperthyroidism/drug therapy , Infusions, Intravenous , Methimazole/administration & dosage , Adult , Aged , Drug Administration Routes , Humans , Male , Thyroid Gland/pathology , Time Factors
8.
Can J Anaesth ; 52(1): 100-4, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15625265

ABSTRACT

PURPOSE: The purpose of this study was to determine if the application of a BURP maneuver to the cricoid cartilage would combine the benefits of both the BURP and the Sellick maneuvers, resulting in an improved glottic view and offer the potential of protection against passive gastric regurgitation. METHODS: This was a double-blind, prospective, randomized, crossover trial. Forty-three patients scheduled for elective surgery participated in this study. General anesthesia was induced using fentanyl, propofol and rocuronium. In a random sequence for each case and blinded to the laryngoscopist, one of three maneuvers was carried out. Direct vertical pressure, using 30 newtons, a BURP maneuver with cricoid pressure, or no pressure was applied to the cricoid and the laryngoscopic view was ascertained. A separate laryngoscopy was conducted for each maneuver and the views were graded as good (part of the glottis seen), poor (only the arytenoids were seen) or no view (only the epiglottis was seen). Endotracheal intubation was then performed in each case. RESULTS: The results showed that the combination of the BURP maneuver and cricoid pressure worsened the view obtained at laryngoscopy in 30% of cases (P = 0.007). Cricoid pressure alone worsened the view in 12.5% of cases (P = 0.279). No difference was seen in 65% of cases. All patients but one were intubated easily. CONCLUSION: There is no benefit to routinely applying a modified "BURP" maneuver to the cricoid cartilage during rapid sequence induction of anesthesia.


Subject(s)
Anesthesia, Inhalation , Cricoid Cartilage/physiology , Glottis/anatomy & histology , Thyroid Cartilage/physiology , Adult , Cross-Over Studies , Double-Blind Method , Female , Gastroesophageal Reflux/prevention & control , Humans , Intraoperative Complications/prevention & control , Laryngoscopy , Male , Pressure , Prospective Studies
10.
Clin Neurophysiol ; 114(9): 1729-37, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12948803

ABSTRACT

OBJECTIVE: This study investigated the effects of stimulant medications on the Electroencephalography (EEG) of children with the combined type of attention-deficit/hyperactivity disorder (ADHD) together with excessive beta activity in their EEG. METHODS: Twenty ADHD and 20 control subjects participated in this study. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for total power and absolute and relative power in the delta, theta, alpha and beta bands, and for the theta/alpha and theta/beta ratios. Subjects were placed on a 6-month trial of a stimulant medication and a second EEG was recorded at the end of the trial. RESULTS: The unmedicated ADHD group had greater absolute and relative beta, less absolute and relative alpha, a higher theta/alpha and a lower theta/beta ratio than the control group. In the frontal regions the ADHD group had an increase in total power, absolute theta, absolute and relative beta and the theta/beta ratio, with greater relative delta, relative theta, and absolute and relative alpha in posterior regions. With medication use, absolute beta activity and frontal total power decreased, although these changes represented a reduction in power, not a normalisation. CONCLUSIONS: These results indicate that ADHD children with excessive beta activity in their EEG are probably not hypoaroused as previously suggested, and that beta activity in these children is probably only associated with the impulsivity and/or hyperactivity aspects of the disorder, but may not necessarily be associated with inattention. SIGNIFICANCE: This study is the first to investigate effects of stimulant medications on the EEG of ADHD children with excessive beta activity in their EEG.


Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Beta Rhythm/drug effects , Central Nervous System Stimulants/therapeutic use , Dextroamphetamine/therapeutic use , Methylphenidate/therapeutic use , Attention Deficit Disorder with Hyperactivity/physiopathology , Brain Mapping , Case-Control Studies , Cerebral Cortex/anatomy & histology , Cerebral Cortex/drug effects , Cerebral Cortex/physiology , Child , Diagnostic and Statistical Manual of Mental Disorders , Electroencephalography , Evoked Potentials/drug effects , Evoked Potentials/physiology , Functional Laterality , Humans , Male , Psychometrics , Signal Processing, Computer-Assisted
11.
Clin Neurophysiol ; 114(2): 319-28, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12559240

ABSTRACT

OBJECTIVE: This study investigated the EEG of girls with Attention-deficit/hyperactivity disorder (ADHD). METHODS: Subjects consisted of 100 girls with ADHD between the ages of 8 and 12 years and 40 age- and gender-matched controls. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, and relative power in the delta, theta, alpha and beta bands. Factor analysis was used to group sites into 3 regions, covering frontal, central and posterior regions. The total ADHD group was compared to the control group as well as the data being subjected to cluster analysis. RESULTS: The ADHD subjects had greater total power, more relative theta, and less relative delta, alpha and beta than controls. Cluster analysis indicated the presence of two distinct EEG clusters of girls with ADHD. These were (a) a large subgroup characterized by increased total power, more relative theta, and less relative delta and beta than control subjects; and (b) a small subgroup with a substantially-increased amount of high amplitude theta activity, with deficiencies in all other bands. CONCLUSIONS: These results indicate that girls with ADHD exhibit abnormalities in their EEGs, but there is far less variance in their EEG profiles than is found in boys with the disorder. The results also suggest that there may be distinct groups of girls with ADHD who are not being referred for clinical treatment. Recommendations are made for further research in this population. This study is significant in that it is the first major study to separately investigate the EEG of girls with ADHD.


Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnosis , Attention Deficit Disorder with Hyperactivity/physiopathology , Brain/physiopathology , Electroencephalography , Arousal/physiology , Child , Cluster Analysis , Female , Humans , Sex Factors
SELECTION OF CITATIONS
SEARCH DETAIL