Search

Oxygen isotopes (δ18O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ18O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ18O. Here we investigate the effects of PCP on a stalagmite δ18O record from central Vietnam, spanning 45 - 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ18O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ18O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ18O (δ18Op). Without considering PCP, our interpretations of the δ18O record would have been misleading. To avoid misinterpretations of speleothem δ18O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ18O.

Orbital to millennial-scale variations in Asian monsoon speleothem δ18O have been widely interpreted as records of monsoon intensity and/or rainfall amount. To assess the influence of these and other mechanisms on higher-frequency δ18O variability, we utilize simulations from a spectrally nudged isotope-enabled general circulation model coupled with instrumental climate data to investigate the climatic controls on interannual precipitation δ18O (δ18Op) variability at four key cave locations affected by the Asian monsoon: Qunf Cave, Oman; Mawmluh Cave, India; Tham Mai Cave, Laos; and Dongge Cave, China. Comparison with instrumental climate data shows that interannual δ18Op variations are only weakly related to local precipitation amount at the four sites and are instead controlled primarily by large-scale monsoon intensity and upstream precipitation over the tropical Indo-Pacific region, which influence the δ18O of incoming moisture. Spatial correlations with sea surface temperature and precipitation, composite analyses, and time series analyses show that the El Niño-Southern Oscillation (ENSO) also plays a key role in modulating interannual precipitation δ18Op variability in the region, especially in northern India and Southeast Asia, with positive δ18Op anomalies during El Niño years reflecting increased contribution of high δ18O moisture from the nearby Bay of Bengal. Coherent interannual to decadal δ18O variations seen in high-resolution proxy records from across the Asian monsoon region, likely record monsoon intensity and upstream rainout, whereas ENSO related variability is likely to be strongest in records from northern India and Southeast Asia, with the largest anomalies expected when weak monsoons and El Niño occur together.

Over the past decade, a number of speleothem studies have used radiocarbon (14C) to address a range of palaeoclimate problems. These have included the use of the bomb pulse 14C to anchor chronologies over the last 60 years, the combination of U-Th and 14C measurements to improve the radiocarbon age-calibration curve, and linking atmospheric 14C variations with climate change. An issue with a number of these studies is how to constrain, or interpret, variations in the amount of radioactively dead carbon (i.e. the dead carbon fraction, or DCF) that reduces radiocarbon concentrations in speleothems. In this study, we use 14C, stable-isotopes, and trace-elements in a U-Th dated speleothem from Flores, Indonesia, to examine DCF variations and their relationship with above-cave climate over the late Holocene and modern era. A strong association between the DCF and hydrologically-controlled proxy data suggests that more dead carbon was being delivered to the speleothem during periods of higher cave recharge (i.e. lower δ18O, δ13C and Mg/Ca values), and hence stronger summer monsoon. To explore this relationship, we used a geochemical soil-karst model coupled with 14C measurements through the bomb pulse to disentangle the dominant components governing DCF variability in the speleothem. We find that the DCF is primarily controlled by limestone dissolution associated with changes in open- versus closed-system conditions, rather than kinetic fractionation and/or variations in the age spectrum of soil organic matter above the cave. Therefore, we infer that periods of higher rainfall resulted in a higher DCF because the system was in a more closed state, which inhibited carbon isotope exchange between the karst water dissolved inorganic carbon and soil-gas CO2, and ultimately led to a greater contribution of dead carbon from the bedrock. © 2012.

Objectives: The study's aim was to explore the prevalence of precarious employment (PE) in Wales prior to the COVID-19 pandemic and examine associations with PE domains across socio-demographics and self-reported health., Study Design: A cross-sectional design was used to explore the prevalence of PE in Wales prior to the COVID-19 pandemic, in February 2020., Methods: Data were collected from a national household survey carried out in May/June 2020, with a sample of 1032 residents in Wales. PE was determined using the Employment Precariousness Scale. Associations between experiencing PE and socio-demographic/health characteristics were examined using Chi-squared tests and logistic regression models (multinomial and binary)., Results: Overall, before the pandemic, one in four respondents (26.5%) was in PE, with the most prevalent domains, wages, and disempowerment being experienced by at least 50% of respondents. Worse perceived treatment at work was twice as likely in those reporting pre-existing conditions (adjusted odds ratio [aOR]: 2.45 95% confidence interval [CI]: [1.33-4.49]), poorer general health (aOR: 2.33 95% CI: [1.22-4.47]), or low mental wellbeing (aOR: 2.81 95% CI: [1.34-5.88]). Those with high wage precariousness were three times more likely to report low mental wellbeing (aOR 3.12 95% CI [1.54-6.32])., Conclusions: The creation and provision of secure, adequately paid job opportunities has the potential to reduce the prevalence of PE in Wales. Targeting such employment opportunities to those people currently unwell would have better population health gains., (Copyright © 2024 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.)

Oxygen isotopes (δ 18 O) are the most commonly utilized speleothem proxy and have provided many foundational records of paleoclimate. Thus, understanding processes affecting speleothem δ 18 O is crucial. Yet, prior calcite precipitation (PCP), a process driven by local hydrology, is a widely ignored control of speleothem δ 18 O. Here we investigate the effects of PCP on a stalagmite δ 18 O record from central Vietnam, spanning 45 - 4 ka. We employ a geochemical model that utilizes speleothem Mg/Ca and cave monitoring data to correct the δ 18 O record for PCP effects. The resulting record exhibits improved agreement with regional speleothem δ 18 O records and climate model simulations, suggesting that the corrected record more accurately reflects precipitation δ 18 O (δ 18 O p ). Without considering PCP, our interpretations of the δ 18 O record would have been misleading. To avoid misinterpretations of speleothem δ 18 O, our results emphasize the necessity of considering PCP as a significant driver of speleothem δ 18 O., (© 2024. The Author(s).)

The megatooth shark, † Otodus megalodon , which likely reached at least 15 m in total length, is an iconic extinct shark represented primarily by its gigantic teeth in the Neogene fossil record. As one of the largest marine carnivores to ever exist, understanding the biology, evolution, and extinction of † O. megalodon is important because it had a significant impact on the ecology and evolution of marine ecosystems that shaped the present-day oceans. Some attempts inferring the body form of † O. megalodon have been carried out, but they are all speculative due to the lack of any complete skeleton. Here we highlight the fact that the previous total body length estimated from vertebral diameters of the extant white shark (Carcharodon carcharias) for an † O. megalodon individual represented by an incomplete vertebral column is much shorter than the sum of anteroposterior lengths of those fossil vertebrae. This factual evidence indicates that † O. megalodon had an elongated body relative to the body of the modern white shark. Although its exact body form remains unknown, this proposition represents the most parsimonious empirical evidence, which is a significant step towards deciphering the body form of † O. megalodon .

The winter and summer monsoons in Southeast Asia are important but highly variable sources of rainfall. Current understanding of the winter monsoon is limited by conflicting proxy observations, resulting from the decoupling of regional atmospheric circulation patterns and local rainfall dynamics. These signals are difficult to decipher in paleoclimate reconstructions. Here, we present a winter monsoon speleothem record from Southeast Asia covering the Holocene and find that winter and summer rainfall changed synchronously, forced by changes in the Pacific and Indian Oceans. In contrast, regional atmospheric circulation shows an inverse relation between winter and summer controlled by seasonal insolation over the Northern Hemisphere. We show that disentangling the local and regional signal in paleoclimate reconstructions is crucial in understanding and projecting winter and summer monsoon variability in Southeast Asia., (© 2023. Springer Nature Limited.)

The evolution of the extinct megatooth shark, Otodus megalodon , and its close phylogenetic relatives remains enigmatic. A central question persists regarding the thermophysiological origins of these large predatory sharks through geologic time, including whether O. megalodon was ectothermic or endothermic (including regional endothermy), and whether its thermophysiology could help to explain the iconic shark's gigantism and eventual demise during the Pliocene. To address these uncertainties, we present unique geochemical evidence for thermoregulation in O. megalodon from both clumped isotope paleothermometry and phosphate oxygen isotopes. Our results show that O. megalodon had an overall warmer body temperature compared with its ambient environment and other coexisting shark species, providing quantitative and experimental support for recent biophysical modeling studies that suggest endothermy was one of the key drivers for gigantism in O. megalodon and other lamniform sharks. The gigantic body size with high metabolic costs of having high body temperatures may have contributed to the vulnerability of Otodus species to extinction when compared to other sympatric sharks that survived the Pliocene epoch.

Most paleoclimate studies of Mainland Southeast Asia hydroclimate focus on the summer monsoon, with few studies investigating rainfall in other seasons. Here, we present a multiproxy stalagmite record (45,000 to 4,000 years) from central Vietnam, a region that receives most of its annual rainfall in autumn (September-November). We find evidence of a prolonged dry period spanning the last glacial maximum that is punctuated by an abrupt shift to wetter conditions during the deglaciation at ~14 ka. Paired with climate model simulations, we show that sea-level change drives autumn monsoon rainfall variability on glacial-orbital timescales. Consistent with the dry signal in the stalagmite record, climate model simulations reveal that lower glacial sea level exposes land in the Gulf of Tonkin and along the South China Shelf, reducing convection and moisture delivery to central Vietnam. When sea level rises and these landmasses flood at ~14 ka, moisture delivery to central Vietnam increases, causing an abrupt shift from dry to wet conditions. On millennial timescales, we find signatures of well-known Heinrich Stadials (HS) (dry conditions) and Dansgaard-Oeschger Events (wet conditions). Model simulations show that during the dry HS, changes in sea surface temperature related to meltwater forcing cause the formation of an anomalous anticyclone in the Western Pacific, which advects dry air across central Vietnam, decreasing autumn rainfall. Notably, sea level modulates the magnitude of millennial-scale dry and wet phases by muting dry events and enhancing wet events during periods of low sea level, highlighting the importance of this mechanism to autumn monsoon variability.

Objective: Disruption to working lives spurred by the COVID-19 pandemic may shape people's preferences for future employment. We aimed to identify the components of work prioritized by a UK sample and the employment changes they had considered since the start of the COVID-19 pandemic., Methods: A nationally representative longitudinal household survey was conducted in Wales at two time points between 2020 and 2021., Results: Those in poorer health prioritized flexibility and were more likely to consider retiring. Those with limiting preexisting conditions or low mental well-being were more likely to consider becoming self-employed. Those experiencing financial insecurity (including those with high wage precarity or those furloughed) were more likely to consider retraining, becoming self-employed, or securing permanent employment., Conclusions: Ensuring flexible, secure, and autonomous work is accessible for individuals facing greater employment-related insecurity may be key., Competing Interests: Conflict of interest: None declared., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Occupational and Environmental Medicine.)

Background: Employment is a determinant of health. The COVID-19 pandemic disrupted working lives, forcing individuals to adapt to new ways of working. These shifts might shape people's priorities and their consideration of changes for future work. We examined how these outcomes differed depending on self-reported health status., Methods: In this longitudinal analysis, we used data from the COVID-19 Employment and Health in Wales Study; a nationally-representative household survey of workers aged 18-64 years. Timepoint 1 (T1) data were collected between May 27, 2020, and June 22, 2020, and timepoint 2 (T2) data between Nov 30, 2020, and Jan 29, 2021. Participants who responded at both timepoints were eligible. Respondents selected five employment priorities at both timepoints, and the employment changes they considered during the COVID-19 pandemic at T2 only. We used multivariable logistic regressions (including sociodemographics, current employment factors, and self-reported health) and examined associations with health firstly for employment priorities, and secondly for the consideration of employment changes. Health measures were self-reported general health, limiting pre-existing health conditions (both using National Survey for Wales validated questions), and mental wellbeing (using the shortened Warwick Edinburgh Mental Well-being Scale)., Findings: We analysed data from 592 respondents (382 [65%] women). 766 (56%) of 1358 T1 respondents were excluded as no T2 responses were provided. Those who self-reported poor general health were consistently more likely to prioritise flexible working arrangements than those rating fair or above (T1 adjusted odds ratio [aOR] 2·06 [95% CI 1·10-3·88], p=0·033; T2 aOR 1·87 [95% CI 1·05-3·33], p=0·034). Those with low (as opposed to average) mental wellbeing were more likely to consider securing a permanent contract (aOR 5·49 [95% CI 1·32-22·81], p=0·023, and those with limiting pre-existing conditions were four times more likely to consider becoming self-employed (aOR 4·00 [95% CI 1·35-11·84], p=0·011) than those without., Interpretation: Promoting the adoption of flexible working policies and supporting those in poor health to obtain flexible employment could benefit people in Wales. Those with low mental wellbeing might seek the security of permanent employment, and those with limiting pre-existing conditions might value the autonomy of self-employment., Funding: None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: The aim of the study is to provide insights into the working Welsh adult population's perceptions of the health impacts of working from home (WFH), their ability to WFH, and their WFH preferences., Methods: Data were collected from 615 working adults in Wales between November 2020 and January 2021 in a household survey., Results: More than 45% of those able to WFH reported worsened mental well-being and loneliness. Working from home worsened the diets, physical activity, smoking, and alcohol use of those in poorer health. Approximately 50% were able to WFH, although individuals living in more deprived areas, in atypical employment or with precarious income, were less able to WFH. Nearly 60% wanted to WFH to some capacity., Conclusions: The new way of working introduces new challenges to preserving workforce mental well-being, regulating health behaviors, and tackling inequalities. Hybrid models and targeted health support could make WFH healthier and more equitable., Competing Interests: Griffiths, Gray, Kyle, Song, and Davies have no relationships/conditions/circumstances that present potential conflict of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Occupational and Environmental Medicine.)

Trophic position is a fundamental characteristic of animals, yet it is unknown in many extinct species. In this study, we ground-truth the 15 N/ 14 N ratio of enameloid-bound organic matter (δ 15 N EB ) as a trophic level proxy by comparison to dentin collagen δ 15 N and apply this method to the fossil record to reconstruct the trophic level of the megatooth sharks (genus Otodus ). These sharks evolved in the Cenozoic, culminating in Otodus megalodon , a shark with a maximum body size of more than 15 m, which went extinct 3.5 million years ago. Very high δ 15 N EB values (22.9 ± 4.4‰) of O. megalodon from the Miocene and Pliocene show that it occupied a higher trophic level than is known for any marine species, extinct or extant. δ 15 N EB also indicates a dietary shift in sharks of the megatooth lineage as they evolved toward the gigantic O. megalodon , with the highest trophic level apparently reached earlier than peak size.

Diet is a crucial trait of an animal's lifestyle and ecology. The trophic level of an organism indicates its functional position within an ecosystem and holds significance for its ecology and evolution. Here, we demonstrate the use of zinc isotopes (δ 66 Zn) to geochemically assess the trophic level in diverse extant and extinct sharks, including the Neogene megatooth shark (Otodus megalodon) and the great white shark (Carcharodon carcharias). We reveal that dietary δ 66 Zn signatures are preserved in fossil shark tooth enameloid over deep geologic time and are robust recorders of each species' trophic level. We observe significant δ 66 Zn differences among the Otodus and Carcharodon populations implying dietary shifts throughout the Neogene in both genera. Notably, Early Pliocene sympatric C. carcharias and O. megalodon appear to have occupied a similar mean trophic level, a finding that may hold clues to the extinction of the gigantic Neogene megatooth shark., (© 2022. The Author(s).)

The interpretation of palaeoclimate archives based on oxygen isotopes depends critically on a detailed understanding of processes controlling the isotopic composition of precipitation. In the summer monsoonal realm, like Southeast Asia, seasonally and interannually depleted oxygen isotope ratios in precipitation have been linked to the summer monsoon strength. However, in some regions, such as central Vietnam, the majority of precipitation falls outside the summer monsoon period. We investigate processes controlling stable isotopes in precipitation from central Vietnam by combining moisture uptake calculations with monthly stable isotope data observed over five years. We find that the isotopic seasonal cycle in this region is driven by a shift in moisture source from the Indian Ocean to the South China Sea. This shift is reflected in oxygen isotope ratios with low values (- 8 to - 10‰) during summer and high values during spring/winter (0 to - 3‰), while 70% of the annual rainfall occurs during autumn. Interannual changes in precipitation isotopes in central Vietnam are governed by the timing of the seasonal onset and withdrawal of the Intertropical Convergence Zone, which controls the amount of vapour contributed from each source.

Introduction: Oesophageal atresia ± tracheoesophageal fistula (EA/TEF) associated with congenital heart disease (CHD) carries a worse prognosis than EA/TEF alone. Though the Spitz classification takes major CHD into account, there are no data regarding survival with the specific combination of EA/TEF and Tetralogy of Fallot (TOF). With advances in postnatal care, we hypothesised that, survival is improving in these complex patients. This study reports morbidity and mortality outcomes of newborns with oesophageal atresia and TOF cardiac malformations METHODS: All patients with EA/TEF and TOF treated at Alder Hey Children's Hospital between the years 2000-2020, were identified. Data sets regarding gestation, birth weight, associated anomalies, operative intervention, morbidity, and mortality were analysed., Results: Of a total of 350, EA/TEF patients 9 (2.6%) cases had EA/TEF associated with TOF (M:F 4:5). The median gestational age was 35/40 (range 28-41 weeks) with a median birth weight of 1790 g (range 1060-3350 g). Overall survival was 56% (5/9 cases) and all survivors remain under follow up (range 37-4458 days). Surgical strategies for managing EA/TEF with Fallot's tetralogy included 6/9 primary repairs and 3/9 cases with TEF ligation only (+ gastrostomy ± oesophagostomy)., Conclusions: This study reports outcome data from one of the largest series of EA TEF patients with Fallot's tetralogy. Whilst outcomes may be challenging for this unique patient cohort, survival metrics provide important prognostic information that can be widely shared with health care teams and parents.

Vending machines contribute to growing levels of obesity. They typically contain energy dense, high fat snacks and attempts at persuading consumers to switch to healthier snacks sold within the same machine have had limited success. This study explored the health benefits and cost effectiveness of the complete replacement of regular snacks with healthy items. Two vending machines were manipulated in a 6-month trial, with a healthy and regular range of products alternated between the two machines every fortnight. Healthy vending resulted in a 61% drop in calories sold relative to regular vending, significant with time and product range as random factors. There was no evidence of compensatory behaviour from nearby shop sales nor in multi-item purchases from vending machines. The impact on profit was less clear. Sales dropped by 30% during healthy vending but variability across product range meant that the change was not significant. Overall our results demonstrate that complete healthy vending can be introduced in hospitals without a catastrophic loss in sales nor compensatory behaviours that offset the public health gains of consuming healthier products., Competing Interests: The authors have declared that no competing interests exist.

Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts of Africa and Asia, yet the extent of these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift in human settlement patterns across the region during this period. We report evidence from stalagmite climate records indicating a major decrease of monsoon rainfall in MSEA during the mid- to late Holocene, coincident with African monsoon failure during the end of the Green Sahara. Through a set of modeling experiments, we show that reduced vegetation and increased dust loads during the Green Sahara termination shifted the Walker circulation eastward and cooled the Indian Ocean, causing a reduction in monsoon rainfall in MSEA. Our results indicate that vegetation-dust climate feedbacks from Sahara drying may have been the catalyst for societal shifts in MSEA via ocean-atmospheric teleconnections.

Speleothem oxygen isotope records have revolutionized our understanding of the paleo East Asian monsoon, yet there is fundamental disagreement on what they represent in terms of the hydroclimate changes. We report a multiproxy speleothem record of monsoon evolution during the last deglaciation from the middle Yangtze region, which indicates a wetter central eastern China during North Atlantic cooling episodes, despite the oxygen isotopic record suggesting a weaker monsoon. We show that this apparent contradiction can be resolved if the changes are interpreted as a lengthening of the Meiyu rains and shortened post-Meiyu stage, in accordance with a recent hypothesis. Model simulations support this interpretation and further reveal the role of the westerlies in communicating the North Atlantic influence to the East Asian climate., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Interdecadal modes of tropical Pacific ocean-atmosphere circulation have a strong influence on global temperature, yet the extent to which these phenomena influence global climate on multicentury timescales is still poorly known. Here we present a 2,000-year, multiproxy reconstruction of western Pacific hydroclimate from two speleothem records for southeastern Indonesia. The composite record shows pronounced shifts in monsoon rainfall that are antiphased with precipitation records for East Asia and the central-eastern equatorial Pacific. These meridional and zonal patterns are best explained by a poleward expansion of the Australasian Intertropical Convergence Zone and weakening of the Pacific Walker circulation (PWC) between ∼1000 and 1500 CE Conversely, an equatorward contraction of the Intertropical Convergence Zone and strengthened PWC occurred between ∼1500 and 1900 CE. Our findings, together with climate model simulations, highlight the likelihood that century-scale variations in tropical Pacific climate modes can significantly modulate radiatively forced shifts in global temperature.

Recent studies have proposed that millennial-scale reorganization of the ocean-atmosphere circulation drives increased upwelling in the Southern Ocean, leading to rising atmospheric carbon dioxide levels and ice age terminations. Southward migration of the global monsoon is thought to link the hemispheres during deglaciation, but vital evidence from the southern sector of the vast Australasian monsoon system is yet to emerge. Here we present a 230thorium-dated stalagmite oxygen isotope record of millennial-scale changes in Australian-Indonesian monsoon rainfall over the last 31,000 years. The record shows that abrupt southward shifts of the Australian-Indonesian monsoon were synchronous with North Atlantic cold intervals 17,600-11,500 years ago. The most prominent southward shift occurred in lock-step with Heinrich Stadial 1 (17,600-14,600 years ago), and rising atmospheric carbon dioxide. Our findings show that millennial-scale climate change was transmitted rapidly across Australasia and lend support to the idea that the 3,000-year-long Heinrich 1 interval could have been critical in driving the last deglaciation.

Midwives and visiting medical officers have a unique relationship within private hospital maternity settings. The effective exchange of accurate information between them is a fundamental element of patient safety and is vital to the success of the clinical handover process. The SHARED (situation, history, assessment, risk, expectation, documentation) project developed, implemented and evaluated a framework and support tools for improving clinical handover in two private maternity hospitals. The project included a pre- and post-study design using clinician surveys, chart audits, patient satisfaction surveys and a review of clinical incident data. A standardised approach to handover, using the SHARED framework with a standardised minimum dataset, improves the accuracy and appropriateness of information.

Fluorescent labeling is widely used in biological and chemical analysis, and the drive for increased throughput is stretching multiplexing capabilities to the limit. The limiting factor in multiplexed analyses is the ability to subsequently deconvolute the signals. Consequently, alternative approaches for interpreting complex data sets are required to allow individual components to be identified. Here we have investigated the application of a novel approach to multiplexed analysis that does not rely on multivariate curve resolution to achieve signal deconvolution. The approach calculates a sample-specific confidence interval for a multivariate (partial least-squares regression (PLSR)) prediction, thereby enabling the estimation of the presence or absence of each fluorophore based on the total spectral signal. This approach could potentially be applied to any multiplexed measurement system and has the advantage over the current algorithm-based methods that the requirement for resolution of spectral peaks is not central to the method. Here, PLSR was used to obtain the concentrations for up to eight dye-labeled oligonucleotides at levels of (0.6-5.3) x 10(-6) M. The sample-specific prediction intervals show good discrimination for the presence/absence of seven of the eight labeled oligonucleotides with efficiencies ranging from approximately 91 to 100%.

The presence of an intraocular foreign body following eye trauma may not be readily apparent. Serous complications may include, inter alia, endophthalmitis, cataract, retinal detachment and siderosis bulbi. We report an iron intraocular injury due to hammering 'metal on metal', which was diagnosed using ultrasonic biomicroscopy and successfully removed. Two months post-operatively, unaided vision was 6/6.

Data are presented for particulate organic carbon (POC) and particulate nitrogen (PN) concentrations in the Humber Estuary and tidal River Ouse Estuary. The POC data were derived from approximately monthly surveys and are consistent with data reported for suspended particulate matter (SPM) in the non-tidal River Ouse (the freshwater river) and with SPM, or bed sediments, in estuarine ecosystems such as the Mississippi, Delaware, San Francisco Bay, Tolo Harbour, the Vellar Estuary and Cochin Backwater, as well as the Loire, Gironde, Ems and Tamar Estuaries. Relative to the dry weight of SPM, the Humber-averaged organic carbon and nitrogen percentages during the year February 1995-March 1996 were 2.6 +/- 0.6% (mean and S.D.) and 0.21 +/- 0.04%, respectively. The ratio of Humber-averaged POC to Humber-averaged PN was 13 +/- 3. Higher POC levels were observed near the Humber's mouth and in the adjacent coastal zone during 'bloom' conditions, and in the upper estuarine reaches during large, winter and springtime freshwater inflows. At these times of high runoff, the POC content of SPM increased progressively up-estuary from the coastal zone to the tidal River Ouse. When inflows became very low, during late spring to early autumn of 1995, both the freshwater-saltwater interface (FSI) and the strengthening turbidity maximum (TM) moved further up-estuary and the POC content of SPM in the upper reaches of the Ouse became lower compared with that immediately down-estuary. This led to a poorly defined POC maximum near the confluence of the Humber, Ouse and Trent, before POC eventually decreased again towards the coastal zone. The lower POC contents in the upper estuarine reaches of the tidal Ouse may have been partly due to POC respiration by heterotrophic bacteria attached to SPM within the TM, consistent with the severe oxygen depletion observed there during high turbidity, summertime spring tides.

Results are presented from a campaign of measurements that were undertaken to examine seasonal variability in physical and chemical fluxes and processes within the Tweed Estuary during the period September 1996-August 1997. The study utilised monthly surveys, each of approximately 1 week duration. This article interprets a subset of the salinity, temperature, turbidity [suspended particulate matter (SPM) levels] and chlorophyll a data. Measurements discussed here were obtained throughout the estuary during high-speed transects that covered the region between the tidal river and the coastal zone. Longitudinal distributions of surface salinity depended strongly on freshwater runoff. During high runoff the surface salinity was low and the freshwater-saltwater interface (FSI) was located close to the mouth. The reverse was true at times of low runoff. Salinity stratification was generally strong. During the surveys, river runoff temperatures ranged from approximately 2 to 18 degrees C and coastal waters (approximately 33 salinity) from approximately 6 to 15 degrees C. Turbidity was low throughout the campaign (SPM < 30 mg l(-1)). Because of rapid flushing times (one or two tides), turbidity tended to mix conservatively between river and coastal waters. Higher coastal turbidity was associated with stronger wind events, and higher fluvial turbidity with spate events. Suspended chlorophyll a levels were usually low throughout the estuary (typically < 2 microg l(-1)) and showed large spatial variability. Because of the rapid flushing of the estuary, it is hypothesised that it was not possible for several algal cell divisions to occur before algae were flushed to the coastal zone. A 'bloom' occurred during the May 1997 survey, when chlorophyll a levels reached 14 microg l(-1). Higher chlorophyll a concentrations at that time occurred at very low salinities, indicating that these waters and algae were largely fluvially derived, and may have resulted from increasing springtime solar irradiation.

A 20-year-old woman presented with chronic renal failure after several months of ibuprofen use for recurrent minor sports injuries. The features of chronic interstitial nephritis were noted on histological examination of a renal biopsy specimen. No improvement in renal function occurred with steroid therapy.

A survey was conducted of admissions to a semirural hospital for Black patients in Bophuthatswana for the period April - March of the years 1959/19610 and 1977/1978 to ascertain whether any measurable change had occurred in the disease pattern. No significant increase over the 18 years was found in the number of admissions for diabetes, appendicitis, peptic ulceration, or coronary heart disease. There was, however, an increase in the incidence of anorectal conditions and in admissions for hypertension.

All 749 deaths recorded by a rural hospital during 1983 were listed in five age groups according to the 9th revision of the International Classification of Diseases. The largest number of deaths were in adults aged 50 years and over and in children aged under 2 years, and the most frequent causes of death were malnutrition, hypertension, prematurity, heart failure and gastro-enteritis.

An investigation was carried out during 1978 to establish the proportion of tuberculosis patients who had a relapse or whose treatment had failed and who presented together with new patients with smear-positive pulmonary tuberculosis at a regional hospital. Reasons for the high number of previously treated patients found in this study (35.8%) are discussed, and include the inadequate experience of the health team in tuberculosis, non-compliance of patients and geographical factors. The hospital-centered comprehensive health scheme seems to offer advantages over the district surgeon scheme in the organization of an adequate tuberculosis programme in a country area.