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Insights from 20 years of temperature parallel measurements in Mauritius around the turn of the 20th century
No full textThere is considerable import in creating more
complete, better understood holdings of early meteorolog-
ical data. Such data permit an improved understanding of
climate variability and long-term changes. Early records are
particularly incomplete in the tropics, with implications for
estimates of global and regional temperature. There is also a
relatively low level of scientific understanding of how these
early measurements were made and, as a result, of their ho-
mogeneity and comparability to more modern techniques
and measurements. Herein we describe and analyse a newly
rescued set of long-term, up to six-way parallel measure-
ments undertaken over 1884–1903 in Mauritius, an island
situated in the southern Indian Ocean. Data include (i) mea-
surements from a well-ventilated room, (ii) a shaded thermo-
graph, (iii) instruments housed in a manner broadly equiv-
alent to a modern Stevenson screen, (iv) a set of measure-
ments by a hygrometer mounted in a Stevenson screen, and
for a much shorter period (v) two additional Stevenson screen
configurations. All measurements were undertaken within an
∼ 80 m radius of each other. To our knowledge this is the first
such multidecadal multi-instrument assessment of meteoro-
logical instrument transition impacts ever undertaken, pro-
viding potentially unique insights. The intercomparison also
considers the impact of different ways of deriving daily and
monthly averages. The long-term comparison is sufficient to
robustly characterize systematic offsets between all the in-
struments and seasonally varying impacts. Differences be-
tween all techniques range from tenths of a degree Celsius to more than 1 ◦C and are considerably larger for maximum and
minimum temperatures than for means or averages. System-
atic differences of several tenths of a degree Celsius also exist
for the different ways of deriving average and mean tempera-
tures. All differences, except two average temperature series
pairs, are significant at the 0.01 level using a paired t test.
Given that all thermometers were regularly calibrated against
a primary Kew standard thermometer maintained by the ob-
servatory, this analysis highlights significant impacts of in-
strument exposure, housing, siting, and measurement prac-
tices in early meteorological records. These results reaffirm
the importance of thoroughly assessing the homogeneity of
early meteorological records
Predicting risk along the suicidality continuum: A longitudinal, nationally representative study of the Irish population during the COVID‐19 pandemic
No full textAbstract
Introduction: Little is known about the lifetime prevalence of different indicators of suicidality in the Irish general population; whether suicidality has increased during
the COVID-19 pandemic; and what factors associated with belonging to different points on a continuum of suicidality risk.
Methods: A nationally representative sample of Irish adults (N = 1,032) completed self-report measures in May 2020 and a follow-up in August 2020 (n = 715).
Results: Lifetime prevalence rates were 29.5% for suicidal ideation, 12.9% for non-suicidal self-injury (NSSI), and 11.2% for attempted suicide. There were no changes in
past two-week rates of NSSI and attempted suicide during the pandemic. Correlations between the indicators of suicidality supported a progression from ideation to NSSI to attempted suicide. Suicidal ideation alone was associated with being male, unemployed, higher loneliness, and lower religiosity. NSSI (with no co-occurring attempted suicide) was associated with a history of mental health treatment. Attempted
suicide was associated with ethnic minority status, lower education, lower income, PTSD, depression, and history of mental health treatment.
Conclusion: Suicidal ideation, NSSI, and attempted suicide are relatively common phenomena in the general adult Irish population, and each has unique psychosocial correlates. These findings highlight important targets for prevention and intervention effort
Southern Hemisphere controls on ITCZ variability in southwest Madagascar over the past 117,000 years
No full textMigration of the inter-tropical convergence zone, driven by changes in seasonal insolation and high northern latitude temperatures, is the primary control on tropical rainfall on geologic timescales. We test this paradigm using the timing of growth of stalagmites from southwest Madagascar to infer the timing of expansion of the ITCZ to the south at its southern limit. Over the past 117 ky, speleothems grew in the study area primarily when two conditions are met: summer insolation greater than the mean and relatively high Southern Hemisphere temperatures as indicted by maxima in Antarctic ice core oxygen isotope ratios. We observe little influence of Northern Hemisphere, millennial scale temperature variability on the pluvial periods. Further, we observe periods during which the ITCZ simultaneously expands or contracts in both hemispheres. Because Antarctic isotope maxima are periods of increased atmospheric CO2, our results have implications for how tropical rainfall in the Southern Hemisphere might respond to global warming
Dynamical–statistical seasonal forecasts of winter and summer precipitation for the Island of Ireland
No full textSeasonal precipitation forecasting is highly challenging for the northwest fringes of Europe due to complex dynamical drivers. Hybrid dynamical–statistical approaches offer potential to improve forecast skill. Here, hindcasts of mean sea level pressure (MSLP) from two dynamical systems (GloSea5 andSEAS5) are used to derive two distinct sets of indices for forecasting winter(DJF) and summer (JJA) precipitation over lead-times of 1–4 months. These indices provide predictors of seasonal precipitation via a multiple linear regression model (MLR) and an artificial neural network (ANN) applied to four Irish rainfall regions and the Island of Ireland. Forecast skill for each model, lead time, and region was evaluated using the correlation coefficient (r) and mean absolute error (MAE), benchmarked against (a) climatology, (b) bias corrected precipitation hindcasts from both GloSea5 and SEAS5, and (c) a zero-order forecast based on rainfall persistence. The MLR and ANN models produced skilful precipitation forecasts with leads of up to 4 months. In all tests, our hybrid method based on MSLP indices outperformed the three benchmarks(i.e., climatology, bias corrected, and persistence). With correlation coefficients ranging between 0.38 and 0.81 in winter, and between 0.24 and 0.78 in summer, the ANN model outperformed MLR in both seasons in most regions and lead-times. Forecast skill for summer was comparable to that in winter and for some regions/lead times even superior. Our results also show that climatology and persistence performed better than direct use of bias corrected dynamical outputs in most regions and lead-times in terms of MAE. We conclude that the hybrid dynamical–statistical approach developed here—by leveraging useful information about MSLP from dynamical systems—enables more skilful seasonal precipitation forecasts for Ireland, and possibly other locations in west-ern Europe, in both winter and summer
Streamflow frequency changes across western Europe and interactions with North Atlantic atmospheric circulation patterns
No full textThis study identifies significant periodicities in streamflow dynamics across western Europe using a hydrological database encompassing 1874 monthly series from catchments in Ireland, the United Kingdom, France, Spain and Portugal, spanning the years 1962 to 2012. Significant and synchronous periodicities with the main atmospheric mechanisms over the North Atlantic sector are also identified using Cross Wavelet Transform and Wavelet Coherence analysis. Principal Components Analysis (PCA) were applied to the different Wavelet transforms analysis in order to summarize the results. These show the occurrence of a 7-years streamflow cycle in a large proportion of catchments within the study domain since the mid 1980's that was not present in earlier periods. The significance, intensity and persistence of the observed regional cycle follows a spatial gradient around the English Channel. We show how the transitive coupling of key atmospheric mechanisms is an influencing factor causing the general change observed. These results suggest the occurrence of a regional change in the periodicities of streamflow across the western European domain. Our results emphasize the non-stationary interaction between streamflow and atmospheric circulation during recent decades and the prominent role of the North Atlantic Oscillation in the newly stablished streamflow cycles
Observation of a meteotsunami on the south coast of Ireland
No full textAt 1440 utc (1540 local time) on Saturday
18 June 2022, when low tide had passed
and the tide was due to rise, the water
drained from the harbours of Union Hall and
nearby Courtmacsherry on the south coast
of Ireland (see Figure 1a). Eyewitnesses captured the event on video,1 with observers
remarking that it reminded them of reports
of the tide receding ahead of the tsunami
in Japan in 2011. The event was captured
by the Irish Marine Institute’s tide gauge in
Union Hall, which recorded a drop in water
level of 70cm in 5min. Compared to the
normal ebb and flow of tides of ~1cm per
minute, this was a dramatic event. The event
impacted most of the Irish south coast,
from Castletownbere to Dunmore East and
onwards to Britain, with reports of unusual
tidal behaviour in Pembrokeshire in South
Wales (see Sibley, 2022, this issue)
Synthesis and characterisation of phenanthroline-oxazine ligands and their Ag(I), Mn(II) and Cu(II) complexes and their evaluation as antibacterial agents
No full textA series of phenanthroline-oxazine ligands were formed by a cyclisation reaction between L-tyrosine amino acid esters and 1,10-phenanthroline-5,6-dione (phendione). The methyl derivative of the phenanthroline-oxazine ligand 1 was complexed with Ag(I), Mn(II) and Cu(II) to form [Ag(1)2]ClO4, [Mn(1)3](ClO4)2 and [Cu(1)3](ClO4)2. The activity of these metal complexes was tested against the bacteria Escherichia coli and Staphylococcus aureus. Each of the metal complexes was more active than 1 against S. aureus and the Mn(II) and Cu(II) complexes also showed greater activity than 1 towards E. coli. The effect of increasing the length of the alkyl moiety on the phenanthroline-oxazine ligands and their corresponding tris homoleptic Cu(II) complexes was investigated. In all cases both the ligands and their complexes were more active against Gram-positive S. aureus than against Gram-negative E. coli. Differences in the lipophilicity of the ligands and their corresponding Cu(II) complexes did alter the antibacterial activity, with the hexyl and octyl derivatives and their complexes showing the greatest activity and comparing well with clinically used antibiotics. The most active Cu(II) complexes and their respective ligands were also active against Methicillin-resistant S. aureus (MRSA). In vivo toxicity studies, conducted using the Galleria mellonella model, showed that all of the compounds were well tolerated by the insect larvae
Toward Sustainable Transportation: Accelerating Vehicle Electrification With Dynamic Charging Deployment
No full textElectric vehicles (EVs) are being actively adopted as a solution to sustainable transportation. However, a bottleneck remains with charging, where two of the main problems are the long charging time and the range anxiety of EV drivers. In this research, we investigate the deployment of dynamic charging systems, i.e., electrified roads that wirelessly charge EVs on the go, with a view to accelerating EV adoption rate. We propose a traffic-based deployment strategy, statistically quantify its impact, and apply the strategy to two case studies of real traffic in New York City (USA) and Xi’an (China). We find that our analytical estimates not only closely match the real data, but they also suggest that dynamic charging considerably extends the driving range of popular EV models in urban mobility. For example, when only 5% of the existing roads in New York City are equipped with this technology, an EV model such as the Nissan Leaf will approximately maintain its battery level without stopping to recharge. If the percentage of charging roads is increased to 10%, then the Leaf will gain nearly 10% of its battery after every 40 kilometers of driving. Our framework provides a solution to public and private organizations that support and facilitate vehicle electrification through charging infrastructure
Evaluating the Accuracy of Stochastic Geometry Based Models for LEO Satellite Networks Analysis
No full textThis letter investigates the accuracy of recently proposed stochastic geometry-based modeling of low earth orbit (LEO) satellite networks. In particular, we use the Wasserstein Distance-inspired method to analyze the distances between different models, including Fibonacci lattice and orbit models. We propose an algorithm to calculate the distance between the generated point sets. Next, we test the algorithm’s performance and analyze the distance between the stochastic geometry model and other more widely acceptable models using numerical results
The Electrochemical Detection of Acetaminophen and the Enantioselective Recognition of Tyrosine Enantiomers using a modified carbon-based electrode
No full textThe beginning of this thesis sees the development and characterisation of a β-cyclodextrin (β- CD) based electrochemical sensor for the electrochemical detection of acetaminophen (paracetamol) and the influence of the accompanying activation of the glassy carbon-based substrate. To incorporate the β-cyclodextrin onto the glassy carbon electrode, electropolymerisation from an aqueous solution of the β-CD monomer was carried out, attempting to form a polymeric β-CD film. The modified electrode was characterised using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy (SEM) coupled with electron dispersive X-Ray analysis (EDX). Optimum conditions for the formation of the sensor were obtained by selecting an ideal potential window, applied potential and also selecting the suitable number of cycles required for modification. A highly efficient sensor was formed when cycling occurred between -2.0 to 2.2 V (vs. SCE) cycled for 15 cycles. The role of the activation of the GCE was also investigated and found to greatly enhance the electrochemical performance of the sensor. It was found that cycling the GCE in a 1.0 M phosphate buffer solution (PBS) at pH 5.5, from -2.0 to 1.1 V (vs. SCE) for 5 cycles, produced a nearly identical voltammogram when compared to a voltammogram where both activation and the electropolymerizing processes on the GCE surface occurred. The modified sensor achieved good sensitivity towards acetaminophen at a neutral pH with a peak current density of 3.8 mA cm-2, with the oxidation of acetaminophen being influenced by pH in which peak currents became lower in more alkaline solutions. In addition, a wide variety of interfering compounds was examined to establish their effect, if any, on the detection of acetaminophen using the β-CD modified GCE. The study concluded that the oxidation of acetaminophen was not influenced by the addition of any of the interference compounds and the sensor was capable of achieving high selectivity.
The final part of this thesis explores the development and characterisation of a chitosan and graphene-modified GCE (CS/GO- GCE) for the electrochemical enantioselective recognition of tyrosine enantiomers. Graphene was incorporated into the sensor by electrodeposition from an aqueous graphene nanoplatelet (GO) dispersed in a 5 mM β-CD solution to prevent agglomeration of the graphene sheets. The biopolymer chitosan was incorporated by electrodeposition from 1% chitosan hydrogel solution (CS) dissolved in 0.2 M acetic acid. The presence of GO and CS were confirmed using cyclic voltammetry, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and potentiostatic measurements. Optimum conditions for development of the CS/GO-modified GCE involved investigating
solvent and polymer concentration of the chitosan hydrogel solution, analysis of the supporting electrolyte used and examining the time sensitive diffusion of molecules into the hydrogel. Electrodeposition of graphene was accomplished by cycling from -1.5 to 0.8 V (vs. SCE) for 5 cycles at 50 mV s-1 using cyclic voltammetry, whilst deposition of the adherent hydrogel polymer was achieved by potentiostatic measurements held for 5 min at -1.5 V (vs. SCE). FTIR spectra showed a combination of CS and GO characteristic peaks suggesting the GO become encapsulated in the CS polymer on the surface of the GCE. The CS/GO-modified GCE achieved good enantioselective recognition between the tyrosine (Tyr) enantiomers, with preferential binding towards L-Tyr displayed. The presence of the chiral hydrogel polymer enabled enantioseparation capability of sensor however it reduced the electrochemical sensitivity of the sensor