The Palmer Drought Index (PDI) is used as an indicator of drought severity, and a particular index value is often the signal to begin or discontinue elements of a drought contingency plan. The ...Standardized Precipitation Index (SPI) was recently developed to quantify a precipitation deficit for different time scales. It was designed to be an indicator of drought that recognizes the importance of time scales in the analysis of water availability and water use. This study compares historical time series of the PDI with time series of the corresponding SPI through spectral analysis. Results show that the spectral characteristics of the PDI vary from site to site throughout the U.S., while those of the SPI do not vary from site to site. They also show that the PDI has a complex structure with an exceptionally long memory, while the SPI is an easily interpreted, simple moving average process
The Palmer Drought Severity Index (PDSI) has been calculated for about 30 years as a means of providing a single measure of meteorological drought severity. It was intended to retrospectively look at ...wet and dry conditions using water balance techniques. The Standardized Precipitation Index (SPI) is a probability index that was developed to give a better representation of abnormal wetness and dryness than the Palmer indices. Before the user community will accept the SPI as an alternative to the Palmer indices, a standard method must be developed for computing the index. Standardization is necessary so that all users of the index will have a common basis for both spatial and temporal comparison of index values. If different probability distributions and models are used to describe an observed series of precipitation, then different SPI values may be obtained. This article describes the effect on the SPI values computed from different probability models as well as the effects on dry event characteristics. It is concluded that the Pearson Type III distribution is the "best" universal model, and that the reliability of the SPI is sample size dependent. It is also concluded that because of data limitations, SPIs with time scales longer than 24 months may be unreliable. An internet link is provided that will allow users to access Fortran 77 source code for calculating the SPI.
•This study offers a detailed categorization of road safety communication appeals.•If graphic images are used in cognitive appeals to reason this changes the appeal type.•Appeals to reason draw on a ...variety of approaches to explain risk and limited human capacities.•Threat appeals of enforcement correspond to deterrence theory but also refer to non-legal costs.•Appeals aiming to elicit vulnerability to a crash differ according to inclusion of response efficacy.•Need road safety enforcement appeals that help justify safety rules and enhance public support.
Communication campaigns are employed as an important tool to promote road safety practices. Researchers maintain road safety communication campaigns are more effective when their persuasive appeals, which are central to their communicative strategy, are based on explicit theoretical frameworks. This study's main objectives were to develop a detailed categorization of persuasive appeals used in road safety communication campaigns that differentiate between appeals that appear to be similar but differ conceptually, and to indicate the advantages, limitations and ethical issues associated with each type, drawing on behavior change theories. Materials from over 300 campaigns were obtained from 41 countries, mainly using road safety organizations’ websites. Drawing on the literature, five types of main approaches were identified, and the analysis yielded a more detailed categorizations of appeals within these general categories. The analysis points to advantages, limitations, ethical issues and challenges in using different types of appeals. The discussion summarizes challenges in designing persuasive-appeals for road safety communication campaigns.
As part of a national study of water management during periods of drought, the U.S. Army Corps of Engineers is underwriting the preparation of a national drought atlas. One of the variables being ...analyzed for the atlas is precipitation. A statistical technique known as L-moments is the basis for the analysis. Central to the L-moment technique is the aggregation of site-specific precipitation data into homogeneous regions. This paper concerns a methodology for defining regions of similar precipitation climates that are homogeneous with respect to the statistical distribution of annual precipitation. Included are a discussion of the data, of the necessity for regionalization, and of the iterative use of clustering and an L-moment–based homogeneity test to determine the regions. The methodology resulted in 104 precipitation regions within the continental United States. The number of stations in each region varied from 1 to 97. Problems were encountered mainly in mountainous and in arid areas. They were, however, resolved in all but three regions by examining the orography and/or the data.
Parametric probability distributions can be fit to a dataset by equating sample L moments to those of the fitted distribution. This study examines the mean and mean squared departures of sample L ...moments of monthly precipitation data from large sample values as sample size increases. Mean departures decrease as the sample size increases with values near zero generally occurring with about 30 to 40 or more observations for the central tendency measure, about 40 to 50 or more for the dispersion measure, and about 60 or 70 for the skewness and kurtosis measures. It was also found that the root-mean-square departures appear to decrease linearly with the square root of the sample size. The results are intended to provide guidance for determining sample sizes when applying at-site L moments to monthly precipitation data.
Precipitation quantile values have been computed for 9 probabilities, 8 durations, 12 starting months, and 111 regions across the United States. L-moment methodology has been used for the ...calculations. Discussed are the rationale for selecting the Pearson type III (gamma) and Wakeby distributions, and the confidence that can be placed in the quantile values. Results show that distribution functions become more asymmetrical as the duration decreases, indicating that the median may be a better measure of central tendency than the mean. Portraying the quantile values as a percentage of the median value leads to smooth spatial fields. Computation of quantile values was the first known large-scale application of L-moment methodology. In spite of the complexity of the techniques and the extensive use of personnel and computer resources, the results justify the procedures in terms of preparing easy to use probability statements that reflect underlying physical processes.
ABSTRACT
Public health communication campaigns have been credited with helping raise awareness of risk from chronic illness and new infectious diseases and with helping promote the adoption of ...recommended treatment regimens. Yet many aspects of public health communication interventions have escaped the scrutiny of ethical discussions. With the transference of successful commercial marketing communication tactics to the realm of public health, consideration of ethical issues becomes an essential component in the development and application of public health strategies. Ethical issues in public health communication are explored as they relate to eight topics: ‘targeting’ and ‘tailoring’ public health messages to particular population segments; obtaining the equivalence of informed consent; the use of persuasive communication tactics; messages on responsibility and culpability; messages that apply to harm reduction; and three types of unintended adverse effects associated with public health communication activities that may label and stigmatise, expand social gaps, and promote health as a value. We suggest that an ethical analysis should be applied to each phase of the public health communication process in order to identify ethical dilemmas that may appear subtle, yet reflect important concerns regarding potential effects of public health communication interventions on individuals and society as a whole.
▶ Research highlights ▶ When not considering cost most parents express willingness to install the technology. ▶ Parents estimated relatively high willingness among parents to install the technology. ...▶ Monetary cost rated as a barrier by about half of the parents. ▶ Most parents thought parents should feel obligated to install the technology. ▶ Parents thought the technology would force parents not to be oblivious. ▶ Objecting parents felt the technology erodes trust and confidence in young drivers. ▶ Parents who supported the technology thought it would enhance communication.
In-vehicle technologies that document driving practices have the potential to enhance the driving safety of young drivers, but their installation depends largely on their parents’ willingness and raises ethical dilemmas. This study investigated, using closed and open-ended questions, the views of 906 parents of young drivers in Israel regarding their willingness to install such a technology, and their conceptions of social norms and ethical issues associated with the technology and of factors that would encourage or discourage parents to adopt it. Most believed parents should feel morally obligated to install it. When cost was not a consideration, most said they would, and believed other parents would be willing to install the technology. Fewer (about half) expressed willingness to install it after being told about its estimated cost. Monetary cost was rated as a barrier to install it by about half. Environmental considerations were viewed as an incentive. Parents who supported the installation believed it would serve as a trigger for parent–young driver communication but those who did not thought it would erode trust in the parent–young driver relationship. Most said parents should have access to the monitoring data. Policy implications regarding issues of privacy and resources for parents are discussed.
BACKGROUNDThe recently introduced wireless M2A capsule video endoscopy (CVE) has been demonstrated to be superior to barium follow-through and enteroscopy in diagnosing patients with occult blood ...loss and iron-deficiency anaemia.
OBJECTIVETo further investigate CVE in comparison to barium follow-through and entero-computerized tomography (CT) in establishing the diagnosis of patients with suspected Crohn's disease.
DESIGN AND SETTINGThe study was conducted in one academic hospital. Twenty patients with recurrent abdominal pain and/or weight loss or chronic diarrhoea underwent barium follow-through as their initial examination, followed by CVE (if there was no stricture) and entero-CT. The radiologist that performed the barium follow-through and entero-CT was blinded to the results of the CVE. A blinded reader who was unaware of the study objective diagnosed the results of the CVE. In most cases in which there was a discrepancy between examinations, colonoscopy and ileoscopy were performed. For each patient, the diagnosis and disease extent were recorded.
RESULTSTwenty patients (13 males, 7 females; mean age 31 years, range 20–57) were included in the study. Ninety-five per cent of the patients had abdominal pain, 75% had diarrhoea, and 65% had weight loss. The mean haemoglobin level of the group was 13.1 g% (range 10–15.5). Only 13 patients underwent entero-CT.CVE confirmed the diagnosis of Crohn's disease that was suspected by alternative methods in six of the 20 patients. CVE made the diagnosis of Crohn's disease in six patients that had normal barium follow-through or entero-CT. CVE ruled out a diagnosis of Crohn's disease suspected by other modalities in three patients. CVE extended the involvement of Crohn's disease in three of the patients, and established new diagnoses in two patients.
SUMMARYCVE established new diagnoses, confirmed existing diagnoses, enlarged the extent of the disease, and ruled out the suspicion of Crohn's disease in 70% of the patients. Barium follow-through established diagnoses, measured the extent of the disease, and ruled out the suspicion of Crohn's disease in 37% of the patients.The capsule detected all of the lesions diagnosed by barium follow-through and entero-CT. CVE detected additional lesions that were not detected by other modalities in 47% of cases and ruled out lesions that were detected by other modalities in 16% of cases (P < 0.05).
CONCLUSIONCVE is a superior and more sensitive procedure than barium follow-through and entero-CT in establishing the diagnosis and estimating the extent of Crohn's disease.
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