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PubMed1986

Early warning skin signs in AIDS and persistent generalized lymphadenopathy.

Distinctive patterns of skin disease other than Kaposi's sarcoma have been in patients with AIDS, in others with persistent generalized lymphadenopathy (PGL) and in a group at high risk of developing AIDS. We found a chronic acneiform folliculitis on the face, back, chest and buttocks, extensive cutaneous fungal infections and a striking neck and beard impetigo. These skin diseases were not present in asymptomatic male homosexual control subjects, 32% of whom were found to have antibodies to human T cell lymphotropic virus type III (HTLV-III). We regard these dermatoses as early warning signs of AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed2005

Measurement of phycocyanin fluorescence as an online early warning system for cyanobacteria in reservoir intake water.

Cyanobacterial blooms in drinking water reservoirs may cause a variety of water quality problems, including those of taste and odor, and can compromise the water supply destined for human consumption. In response to this problem an online monitoring tool for analyzing the cyanobacterial concentration in intake water is of practical value. This study demonstrated a positive correlation between phycocyanin fluorescence and cyanobacterial biomass during Microcystis aeruginosa blooms in a lowland drinking water reservoir, using online detection. The highest correlation coefficients were found for a cyanobacterial biomass concentration below 15 mg freshweight/L, indicating that this method can be an effective early warning system. Rapid changes in fluorescence were observed when wind drift moved higher cyanobacterial concentrations into the water intake, indicating that fluorescence could be employed as a quick warning for changed requirements for plant operations.

Biomass↗

PubMed2006

Responses of antioxidants in the lichen Ramalina lacera may serve as an early-warning bioindicator system for the detection of air pollution stress.

The aim of this study was to identify, in the lichen Ramalina lacera, antioxidants that could provide indications of air pollution stress, and respond earlier than traditionally used structural/physiological parameters. The pollution-sensitive lichen R. lacera was transplanted from its relatively unpolluted natural habitat to two air-polluted sites for a period of up to 6 months. The superoxide dismutase and catalase activities, total water- and lipid-soluble low-molecular-weight antioxidant capacities and chlorophyll b/chlorophyll a ratios were assessed every 6 weeks. The earliest signs of oxidative stress were detected in the activities of fungal copper/zinc-superoxide dismutase, algal iron-superoxide dismutase and water-soluble low-molecular-weight antioxidants, which increased significantly as early as 42 days after exposure to pollution. Catalase activity increased in lichens transplanted to the polluted sites after 90 days. All activities decreased towards the end of the experiment. The impact of air pollution on R. lacera, using the traditionally employed parameter of chlorophyll b/chlorophyll a ratio, was only detected after 6 months of exposure to air pollution. Our results indicate that antioxidant parameters may serve as improved early-warning indicators of air pollution stress in lichens.

Air Pollutants↗

PubMed2005

Intracellular and extracellular components as bacterial thermometers, and early warning against thermal stress.

Responses induced by cold or heat are triggered following detection of temperature changes by specific sensing molecules, complexes or structures. Low temperature responses are often induced following sensing of cold-induced falls in membrane fluidity, such changes turning-on or -off enzymic activities in membrane proteins, although ribosomes and DNA may also function in cold perception. Many thermal sensors are components of structures damaged by the heat, with sensing involving changes to ribosomes, DNA, intracellular proteins and, less commonly, membrane fluidity. Additionally, secreted proteins (extracellular sensing components, ESCs) detect temperature increases i.e. act as thermometers, with ESC activation in the medium, by the stimulus, converting such sensors to extracellular signalling molecules, the extracellular induction components (EICs), which induce thermal responses. Several ESC/EIC pairs trigger thermal responses, and have the unique property of giving early warning of the stress by diffusing to regions (and organisms) not yet exposed to elevated temperatures.

Bacteria↗

PubMed2001

Infectious disease surveillance in North Rhine-Westphalia: first steps in the development of an early warning system.

It is often difficult to detect warning signals on infectious disease outbreaks from raw surveillance data. Data need to be used for a timely generation and distribution of information on the current state of infectious diseases. This offers the opportunity to detect outbreaks and to initiate preventive measures. To improve the surveillance system in North Rhine-Westphalia we have introduced an infectious disease barometer, a simple tool based on weekly notification data. The aim of this tool is not to provide in depth data analysis, but to help to detect clusters or outbreaks. This can be the first step in the development of an early warning system and can support epidemiological investigation and policy making.

Communicable Diseases, Emerging↗

PubMed2026

[Genomic evolution and epidemiological patterns of respiratory syncytial virus and their implications for surveillance and early warning].

Respiratory syncytial virus (RSV) is an important respiratory pathogen in infants, young children and older adults. Based on global RSV genomic surveillance data, this review systematically summarizes the geographic distribution, seasonal epidemic patterns, and long-term evolutionary trends of RSV, with particular emphasis on the sustained circulation and evolutionary mechanisms of dominant genotypes such as ON1 in RSV-A and BA9 in RSV-B. Current evidence indicates that RSV transmission dynamics are tightly coupled with viral evolution. The G gene evolves relatively rapidly and contains multiple positively selected sites, suggesting an important role in immune escape and population adaptation. In recent years, changes in social behavior patterns and population immunity have further disrupted the seasonal rhythm of RSV and may have influenced the spread of dominant genotypes. Under routine respiratory infectious disease surveillance, strengthened genomic monitoring and integration of multi-source data are needed to improve early warning of abnormal RSV epidemics and variant-associated risks, thereby providing prospective evidence for protecting high-risk populations and informing public health decision-making.

Humans↗

PubMed2005

Late lessons from early warnings: towards precaution and realism in research and policy.

This paper focuses on the evidentiary aspects of the precautionary principle. Three points are highlighted: (i) the difference between association and causation; (ii) how the strength of scientific evidence can be considered; and (iii) the reasons why regulatory regimes tend to err in the direction of false negatives rather than false positives. The point is made that because obtaining evidence of causation can take many decades of research, the precautionary principle can be invoked to justify action when evidence of causation is not available, but there is good scientific evidence of an association between exposures and impacts. It is argued that the appropriate level of proof is context dependent, as "appropriateness" is based on value judgements about the acceptability of the costs, about the distribution of the costs, and about the consequences of being wrong. A complementary approach to evaluating the strength of scientific evidence is to focus on the level of uncertainty. If decision makers are made aware of the limitations of the knowledge base, they can compensate by adopting measures aimed at providing early warnings of un-anticipated effects and mitigating their impacts. The point is made that it is often disregarded that the Bradford Hill criteria for evaluating evidence are asymmetrical, in that the applicability of a criterion increases the strength of evidence on the presence of an effect, but the inapplicability of a criterion does not increase the strength of evidence on the absence of an effect. The paper discusses the reason why there are so many examples of regulatory "false negatives" as opposed to "false positives". Two main reasons are put forward: (i) the methodological bias within the health and environmental sciences; and (ii) the dominance within decision-making of short term economic and political interests. Sixteen features of methods and culture in the environmental and health sciences are presented. Of these, only three features tend to generate "false positives". It is concluded that although the different features of scientific methods and culture produce robust science, they can lead to poor regulatory decisions on hazard prevention.

Decision Making↗

PubMed1996

An "early warning system' for health needs: surveillance of the quality of clinical services by audit of extra-contractual referrals (ECRs).

Extra-contractual referrals (ECRs) can be a cause of considerable anxiety to purchasing authorities, mainly because of their potential to generate unexpected expenditure. But ECRs can also be used as a tool for monitoring the demand for, and quality of, clinical services. ECRs were studied in the Darlington Health Authority district using a variety of methods including inter-disciplinary meetings, a series of interviews with local GPs, and a questionnaire to general practitioners on 230 consecutive ECRs. The methods and results of the questionnaire study are presented. The commonest reasons for making ECRs included the mistaken belief that a contract existed with the ECR provider, patient dissatisfaction with the local provider, and referral to benefit from shorter waiting lists. ECRs for bone-mass densitometry, orthopaedics, and ear nose and throat services were over-represented. Questionnaire results were validated by comparison with an interview study of all GPs in the district. We conclude that trends in ECRs can be monitored as a convenient "early warning system' to alert purchasing authorities to changes in demand or perceived problems with local provider units. ECR data must be interpreted in the context of further local background information from sources such as GPs and public health physicians. In the case of Darlington, scrutiny of ECRs has led to changes in services and contracts.

Contract Services↗

PubMed2002

Early warning of disturbances in a laboratory-scale MSW biogas process.

The use of near-infrared spectroscopy (NIR) to monitorthe dynamics of a biogas process was evaluated using multivariate data analysis. The digester was a completely stirred 8 I tank reactor fed with the organic fraction of source-sorted MSW. Intermittently the digester was overloaded with feed. Before and after overload on-line monitoring of NIR spectra and off-line analysis in the liquid and the gas phase of traditional chemical variables and microbial biomass, determined as total concentration of phospholipid fatty acids (PLFA and PLEL), were done. The dynamics that occurred due to overloading could be followed using principal component analysis of the obtained NIR-spectra. In addition, the response to changes in the digester fluid was reproducible and could be detected within five minutes, which can be considered as real-time monitoring. Selected wavelengths in the region 800-2,000 nm were used to make a PLS1 -regression with propionate. The regression resulted in a good correlation for propionate (R= 0.94 and RMSEP of 0.21 g/l in the range of 0.3-3 g/l). The results indicate the possibility to develop an early warning biogas control system based on near-infrared spectroscopy monitoring of propionate.

Automation↗

PubMed2003

Early warning and NHS Direct: a role in community surveillance?

BACKGROUND: NHS Direct is a nurse-led telephone help line that covers the whole of England and Wales. NHS Direct derived data are being used for community surveillance, the purpose of which is to detect a local or national increase in symptoms reported by callers. The system has the potential to identify an increase in symptoms reported by callers about people in the prodromal stages of illness caused by the deliberate release of a biological or chemical agent. There are no other community surveillance projects existing on a national scale that utilize electronic daily data. METHODS: We describe the surveillance system and calls to NHS Direct between December 2001 and July 2002. Confidence limits have been constructed for 10 key algorithms at each site and control charts devised for five of these algorithms at sites covering the key urban areas. RESULTS: Daily reporting has been achieved from NHS Direct sites in England and Wales. High levels of activity in specific algorithms at both national and regional levels have been detected. A sustained national increase in calls about fever occurred in January 2002. CONCLUSION: Although the project is still at an early stage, daily analysis of NHS Direct data has the potential to detect symptoms in the community that could be related to deliberate releases of chemical or biological agents or to outbreaks of disease. For this surveillance to act as an 'early warning' of illness resulting from a microbiological or chemical cause, the NHS Direct surveillance needs to be fully integrated into an appropriate public health response (which may require diagnostic samples to be taken from callers).

Adolescent↗

PubMed2006

Application of a multi-channel system for continuous monitoring and an early warning system.

A multi-channel continuous toxicity monitoring system developed in our laboratory, based on two-stage mini-bioreactors, was successfully implemented in the form of computer-based data acquisition. The multi-channel system consists of a series of a two-stage minibioreactor systems connected by a fiber optic probe to a luminometer, and uses genetically engineered bioluminescent bacteria for the detection of the potential toxicity from the soluble chemicals. This system can be stably and continuously operated due to the separation of the culture reactor from the test reactor and accomplish easy and long-term monitoring without system shut down by abrupt inflows of severe polluting chemicals. Four different recombinant bioluminescent bacteria were used in different channels so that the modes of the samples toxicities can be reasonably identified and evaluated based upon the response signature of each channel. The bioluminescent signatures were delivered from four channels by switching one at once, while the data is automatically logged to an IBM compatible computer. We also achieved the enhancement of the system through the manipulation of the dilution rate and the use of thermo-lux fusion strains. Finally, this system is now being implemented to a drinking water reservoir and river for remote sensing as an early warning system.

Bacteria↗

PubMed2006

Modelling entomological-climatic interactions of Plasmodium falciparum malaria transmission in two Colombian endemic-regions: contributions to a National Malaria Early Warning System.

BACKGROUND: Malaria has recently re-emerged as a public health burden in Colombia. Although the problem seems to be climate-driven, there remain significant gaps of knowledge in the understanding of the complexity of malaria transmission, which have motivated attempts to develop a comprehensive model. METHODS: The mathematical tool was applied to represent Plasmodium falciparum malaria transmission in two endemic-areas. Entomological exogenous variables were estimated through field campaigns and laboratory experiments. Availability of breeding places was included towards representing fluctuations in vector densities. Diverse scenarios, sensitivity analyses and instabilities cases were considered during experimentation-validation process. RESULTS: Correlation coefficients and mean square errors between observed and modelled incidences reached 0.897-0.668 (P > 0.95) and 0.0002-0.0005, respectively. Temperature became the most relevant climatic parameter driving the final incidence. Accordingly, malaria outbreaks are possible during the favourable epochs following the onset of El Niño warm events. Sporogonic and gonotrophic cycles showed to be the entomological key-variables controlling the transmission potential of mosquitoes' population. Simulation results also showed that seasonality of vector density becomes an important factor towards understanding disease transmission. CONCLUSION: The model constitutes a promising tool to deepen the understanding of the multiple interactions related to malaria transmission conducive to outbreaks. In the foreseeable future it could be implemented as a tool to diagnose possible dynamical patterns of malaria incidence under several scenarios, as well as a decision-making tool for the early detection and control of outbreaks. The model will be also able to be merged with forecasts of El Niño events to provide a National Malaria Early Warning System.

Animals↗

PubMed2005

Intrathoracic impedance monitoring in patients with heart failure: correlation with fluid status and feasibility of early warning preceding hospitalization.

BACKGROUND: Patients with heart failure are frequently hospitalized for fluid overload. A reliable method for chronic monitoring of fluid status is therefore desirable. We evaluated an implantable system capable of measuring intrathoracic impedance to identify potential fluid overload before heart failure hospitalization and to determine the correlation between intrathoracic impedance and standard measures of fluid status during hospitalization. METHODS AND RESULTS: Thirty-three patients with NYHA class III and IV heart failure were implanted with a special pacemaker in the left pectoral region and a defibrillation lead in the right ventricle. Intrathoracic impedance was regularly measured and recorded between the lead and the pacemaker case. During hospitalizations, pulmonary capillary wedge pressure and fluid status were monitored. Ten patients were hospitalized for fluid overload 25 times over 20.7+/-8.4 months. Intrathoracic impedance decreased before each admission by an average of 12.3+/-5.3% (P<0.001) over an average of 18.3+/-10.1 days. Impedance reduction began 15.3+/-10.6 days (P<0.001) before the onset of worsening symptoms. There was an inverse correlation between intrathoracic impedance and pulmonary capillary wedge pressure (r=-0.61, P<0.001) and between intrathoracic impedance and net fluid loss (r=-0.70, P<0.001) during hospitalization. Automated detection of impedance decreases was 76.9% sensitive in detecting hospitalization for fluid overload, with 1.5 false-positive (threshold crossing without hospitalization) detections per patient-year of follow-up. CONCLUSIONS: Intrathoracic impedance is inversely correlated with pulmonary capillary wedge pressure and fluid balance and decreased before the onset of patient symptoms and before hospital admission for fluid overload. Regular monitoring of impedance may provide early warning of impending decompensation and diagnostic information for titration of medication.

Aged↗

PubMed2005

Peak airway pressure increase is a late warning sign of partial endotracheal tube obstruction whereas change in expiratory flow is an early warning sign.

If peak inspiratory airway pressure (Ppeak) is used to monitor airway patency, progressive obstruction of the endotracheal tube (ETT) resulting from secretions can go undetected for a prolonged period. The reason is that any increase in Ppeak depends not only on the degree of narrowing but also on the inspiratory flow () rate. Although the impact of narrowing on low inspiratory is small, its decelerating effect on the high expiratory is pronounced and, hence, easily detectable. Dividing the volume-flow curve of a passive expiration into five consecutive segments (slices) and calculating the time constants (tau(Epsilon)) of these slices allows for analyzing whether and how expiratory is impeded by a partial obstruction. In nine piglets, during volume-controlled ventilation, three grades of ETT obstruction were created with an external clamp. In all animals the tau(E) increased with ETT obstruction (mean for the first slice: 550 ms with unobstructed ETT; grade 1: 661; grade 2: 877; and grade 3: 1563 ms, respectively) and this increase was significant with grade 2 and 3 obstruction. Ppeak, by contrast, did not increase significantly (base: 13, grade 1: 14, grade 2: 15 cm H(2)O) until the most severe (grade 3: 20 cm H(2)O) obstruction was created. We conclude that partial obstruction of the ETT can be reliably monitored with the expiratory V signal and has the potential of monitoring ETT narrowing in ventilator-dependent patients independent of the inspiratory pattern applied.

Airway Resistance↗

PubMed1993

Early warning signs of functional illiteracy: predictors in childhood and adolescence.

Early childhood, middle childhood, and early adolescence determinants of functional literacy in adulthood are investigated, using 20-year longitudinal data from a sample of black children of teenaged mothers from the Baltimore metropolitan area. Document literacy was assessed by a test that consisted of a subset of items of the National Assessment of Educational Progress (NAEP) adult literacy test. The Baltimore sample is compared to the NAEP sample. Family environmental factors, early childhood developmental level, and educational career factors were considered as predictors of young adulthood literacy. Preschool cognitive and behavioral functioning is highly predictive of literacy in young adulthood, even when the effects of family environmental characteristics, including living arrangements, the quality of the home environment, maternal education, and income, are controlled. Grade failure in elementary school is also associated with literacy, but this effect disappears when the measure of preschool abilities is controlled. Family environmental factors that are predictive of literacy include maternal education, family size in early childhood, maternal marital status, and income in middle childhood and early adolescence. Policy implications of these findings are discussed.

Achievement↗

PubMed2001

The role of early warning symptoms in the detection and prevention of relapse in schizophrenia.

OBJECTIVE: The capacity of most clinical programs to detect early signs of relapse in schizophrenia and to implement strategies to prevent clinical progression remains unevaluated. The aim of this paper is to review the literature on the detection of relapse in schizophrenia and to draw conclusions that may be of use in the implementation of clinical programs. METHOD: The relevant literature identified by standard search methods is explored and analysed. RESULTS: Few studies have the capacity to directly address the question as to whether it is possible to predict relapse with a high degree of predictive power. Recently, the implementation of a multifactorial approach to relapse prediction appears to have offered substantial benefits. CONCLUSIONS: The prediction of episodes of psychotic relapse is a realistic goal. Evidence indicates that interventions based upon programs of early detection can reduce rates of illness relapse. Prediction of relapse is most successful when implemented in a multifactorial way that involves specific and non-specific symptoms, structured ratings, clinical judgement, families, patients and clinicians.

Humans↗

PubMed2005

Climate science and famine early warning.

Food security assessment in sub-Saharan Africa requires simultaneous consideration of multiple socio-economic and environmental variables. Early identification of populations at risk enables timely and appropriate action. Since large and widely dispersed populations depend on rainfed agriculture and pastoralism, climate monitoring and forecasting are important inputs to food security analysis. Satellite rainfall estimates (RFE) fill in gaps in station observations, and serve as input to drought index maps and crop water balance models. Gridded rainfall time-series give historical context, and provide a basis for quantitative interpretation of seasonal precipitation forecasts. RFE are also used to characterize flood hazards, in both simple indices and stream flow models. In the future, many African countries are likely to see negative impacts on subsistence agriculture due to the effects of global warming. Increased climate variability is forecast, with more frequent extreme events. Ethiopia requires special attention. Already facing a food security emergency, troubling persistent dryness has been observed in some areas, associated with a positive trend in Indian Ocean sea surface temperatures. Increased African capacity for rainfall observation, forecasting, data management and modelling applications is urgently needed. Managing climate change and increased climate variability require these fundamental technical capacities if creative coping strategies are to be devised.

Africa South of the Sahara↗

PubMed1990

Early warning of fetal compromise--absent end diastolic flow?

This report deals with the use of a relatively new investigative technique (Doppler ultrasound) in the management of a case of early onset pre-eclampsia and discusses the benefit of this new technique over conventional methods of fetal monitoring.

Adult↗