Bayesian approach for sample size determination, illustrated with Soil Health Card data of Andhra Pradesh (India).

A crucial decision in designing a spatial sample for soil survey is the number of sampling locations required to answer, with sufficient accuracy and precision, the questions posed by decision makers at different levels of geographic aggregation. In the Indian Soil Health Card (SHC) scheme, many thousands of locations are sampled per district. In this paper the SHC data are used to estimate the mean of a soil property within a defined study area, e.g., a district, or the areal fraction of the study area where some condition is satisfied, e.g., exceedence of a critical level. The central question is whether this large sample size is needed for this aim. The sample size required for a given maximum length of a confidence interval can be computed with formulas from classical sampling theory, using a prior estimate of the variance of the property of interest within the study area. Similarly, for the areal fraction a prior estimate of this fraction is required. In practice we are uncertain about these prior estimates, and our uncertainty is not accounted for in classical sample size determination (SSD). This deficiency can be overcome with a Bayesian approach, in which the prior estimate of the variance or areal fraction is replaced by a prior distribution. Once new data from the sample are available, this prior distribution is updated to a posterior distribution using Bayes' rule. The apparent problem with a Bayesian approach prior to a sampling campaign is that the data are not yet available. This dilemma can be solved by computing, for a given sample size, the predictive distribution of the data, given a prior distribution on the population and design parameter. Thus we do not have a single vector with data values, but a finite or infinite set of possible data vectors. As a consequence, we have as many posterior distribution functions as we have data vectors. This leads to a probability distribution of lengths or coverages of Bayesian credible intervals, from which various criteria for SSD can be derived. Besides the fully Bayesian approach, a mixed Bayesian-likelihood approach for SSD is available. This is of interest when, after the data have been collected, we prefer to estimate the mean from these data only, using the frequentist approach, ignoring the prior distribution. The fully Bayesian and mixed Bayesian-likelihood approach are illustrated for estimating the mean of log-transformed Zn and the areal fraction with Zn-deficiency, defined as Zn concentration <0.9 mg kg -1, in the thirteen districts of Andhra Pradesh state. The SHC data from 2015-2017 are used to derive prior distributions. For all districts the Bayesian and mixed Bayesian-likelihood sample sizes are much smaller than the current sample sizes. The hyperparameters of the prior distributions have a strong effect on the sample sizes. We discuss methods to deal with this. Even at the mandal (sub-district) level the sample size can almost always be reduced substantially. Clearly SHC over-sampled, and here we show how to reduce the effort while still providing information required for decision-making. R scripts for SSD are provided as supplementary material.

Characterizing soil hydrology in the Indo-Gangetic plain of Bihar, India: Methods and preliminary results.

In the Eastern Gangetic Plain (EGP) soil hydrology is a major determinant of land use and also governs the ecosystem services derived from cropping systems, particularly greenhouse gas (GHG) emissions from rice fields. To characterize patterns of soil hydrology in these, daily field monitoring of water levels was conducted during the monsoon (kharif) season in a comparatively wet (2021) and dry (2022) year with flooding depth and drainage tracked with field water tubes across 47 (2021) and 183 (2022) locations. Fields were clustered into hydrologic response types (HRT) which can then be used for land surface modelling, land use recommendations, and to target agronomic interventions that contribute to sustainable development outcomes. Clusters based on two methods of summarizing a single information source were compared. The information source was a time-series of field water-level observations, and the two methods were (1) the original time-series and their first differences and (2) a set of derived hydrologic descriptors that are conceptually related to greenhouse gas (GHG) emissions. Clustering was (1) by k-means with an optimization of cluster numbers and (2) by hierarchical clustering with the same number of clusters as identified by k-means. Hydrologic behaviour shifted dramatically between growing seasons, and it was not possible to identify consistent HRT's across years. The clusters had only a weak relation with soil properties, almost no relation with farmer perception of relative landscape position, and no relation with rice establishment method. Clusters based on time-series were moderately well predicted in the dry year 2022 by optimized random forest models, with the most important predictors being the number of irrigations, seasonal precipitation, pre-monsoon groundwater levels, seasonal groundwater level change, and pH, this latter as a surrogate for landscape position and other soil properties. In the wet year 2021 clusters were (poorly) predicted by just seasonal precipitation and pre-monsoon groundwater levels. This shows the complex relation of soil hydrology with landscape position and land management, as well as synoptic climate. By contrast, clusters based on the descriptors were not well-matched with those from the time-series, and could not be well predicted by random forest models. This shows that different clustering criteria may result in different interpretations of the landscape hydrology and thus different heuristics for anticipating the hydrology of a given field under different management choices.

The choice of spectral similarity algorithms influences suspected soil sample provenance.

Similarity algorithms are commonly used in soil forensic applications to help identify similar samples from an existing reference library as possible source locations of unknown target samples. These algorithms are well-suited to compare soil spectra. However, different similarity algorithms may lead to different clusters of similar samples, and thus different strengths of evidence in forensic investigations. To quantify this, we conducted a study to evaluate the influence of seven similarity algorithms on soil provenance, using as a sample set a soil spectral library consisting of 280 soil profiles from Anhui Province, China. This library includes three spatial scales of datasets: provincial (DSp), county (DSc) and field (DSf). A set of ten samples covering a wide range of spectra variations were selected from the DSf dataset as the "unknown" samples, with the remaining being used as the reference samples. This study aimed to: (1) evaluate how several commonly-used similarity algorithms, namely Euclidean distance (ED), Mahalanobis distance (MD), Spectral angle mapper (SAM), and Spectral information divergence (SID), as well as variants of several of these measured in standardized principal component space computed from the spectra (ED_PCA, MD_PCA and SAM_PCA), influence the identification of the matched similar samples; (2) determine the overlap in sample selection between different similarity algorithms; (3) propose best practices for similarity algorithms applied to soil forensic analysis using spectroscopy. The use of different similarity algorithms did influence the selection of most similar samples. The similarity algorithms calculated in PC space (ED_PCA, MD_PCA and SAM_PCA) performed slightly better than their counterparts calculated in spectral space. Due to the availability of a detailed spectral library, regardless of the different similarity algorithms used, the matched most similar samples were all located close to the unknowns, mostly within 3 km, with one exception. That is, the varied choices of different similarity algorithms hardly influenced the conclusion of soil provenance in this case. In general, MD_PCA, SAM and ED were the best similarity algorithms overall. However, since there was no single best algorithms for all cases, we recommend the joint use of MD_PCA, SAM and ED as an ensemble. Indications of possible sample provenance from these similarity measured can be useful evidence to complement evidence from other methods in a forensic investigation.

Forensic soil source identification: comparing matching by color, vis-NIR spectroscopy and easily-measured physio-chemical properties.

This study evaluates to what degree soil samples associated in characteristic space are also close in geographical space, i.e., the possible location from which an unknown sample was obtained in a forensic investigation. The study compares similarity computed from Munsell colors, RGB colors, and full visible-near infrared (vis-NIR) spectra by the spectral angle mapper with similarity based on six easily-measured physio-chemical properties. The reference area is Anhui Province, China with three scales of datasets: provincial, county, and field. Ten diverse "unknown" samples were selected by the Kennard-Stone algorithm from the field-scale dataset and their matches in characteristic space from the several datasets were found by the different methods. The geographic distances of the matches to the "unknowns" were used to evaluate the source identification ability. When a detailed library with local samples is present, a limited set of physio-chemical properties achieved higher geographic accuracy than the color and spectral methods. However, with a regional library the spectral and color methods are superior. Distances in RGB space reveal finer differences than exact matching in Munsell space, but whole-spectra matching outperforms both, because of the rich information influenced by more soil properties than influencing color. We recommend the use of soil vis-NIR spectra as a priority indicator for forensic soil analysis because of its success in this study and its ability to work non-destructively on small quantities of soil.

Introduction of integrated care pathways for patients with multiple sclerosis in an inpatient neurorehabilitation setting.

Rehabilitation of progressive neurological disorders such as multiple sclerosis poses particular problems, and clear setting of goals and clinical audit are essential for effective management. Integrated care pathways (ICPs) offer a unique opportunity to document and audit the rehabilitation process. This preliminary study has shown that ICPs are useful in both assessing process and auditing goals. Their introduction has led to the identification of the key worker role within the neurorehabilitation unit (NRU), and has provided an opportunity to increase the participation of patients and carers in the rehabilitation process. Continuing refinement of the pathway is necessary, and its application to other neurological disorders such as cerebrovascular accident may be appropriate.

The Functional Independence Measure: a comparative validity and reliability study.

The majority of measurement scales used to evaluate outcome in rehabilitation are ordinal in nature and consequently statistically valid assessments of change are difficult to make. The Functional Independence Measure (FIM) can be weighted to possess interval properties, potentially allowing more accurate analysis of change. In this study the FIM was compared to the Barthel Index (BI) to determine its validity, reliability and ease of use in two groups of 25 patients undergoing neurorehabilitation. The FIM was considered to be more valid than the BI, and equally reliable in the assessment of disability. When the two disability scores were compared using subjective and objective assessment the agreement between them was comparable, although neither was high.

Lingual abscesses in suckling and weaned lambs.

Lingual abscesses were found in lambs from 2 midwestern flocks. Lesions resulted in reluctance to feed, emaciation, and death. Plant material was demonstrated at the center of abscesses in 1 flock. Veterinarians should examine tongues carefully when investigating lamb mortalities.

ALBERT: a real-time visual feedback computer tool for professional vocal development.

This paper considers the nature of real-time visual feedback for vocal analysis and development and presents a new software tool, called ALBERT (acoustic and laryngeal biofeedback enhancement in real time), designed for use with those developing their voices professionally. This tool embodies several important issues in the provision of real-time visual feedback, including: (a) support for user-configurable visual displays, (b) the ability to use colour as a complementary or sole medium for the presentation of information, (c) the ability to combine algorithmically any number of vocal parameters to create a new single parameter representative of some aspect of vocal measurement which may be displayed and updated in real time, and (d) a rate of information update which may be altered by the user at any point for the most appropriate use according to the context of the feedback task. Several examples of system use are given, including the real-time display of fundamental frequency, jitter, and larynx closed quotient (CQ) parameters in a variety of visual configurations. Several examples are given relating to developing professional voice users, including the derivation of a new parameter which reflects the measure of progress of subjects along a linear correlation line between CQ and the level of energy in the singer's formant region.

A real-time LPC-based vocal tract area display for voice development.

This article reports the design and implementation of a graphical display that presents an approximation to vocal tract area in real time for voiced vowel articulation. The acoustic signal is digitally sampled by the system. From these data a set of reflection coefficients is derived using linear predictive coding. A matrix of area coefficients is then determined that approximates the vocal tract area of the user. From this information a graphical display is then generated. The complete cycle of analysis and display is repeated at approximately 20 times/s. Synchronised audio and visual sequences can be recorded and used as dynamic targets for articulatory development. Use of the system is illustrated by diagrams of system output for spoken cardinal vowels and for vowels sung in a trained and untrained style.

Voice development under training with and without the influence of real-time visually presented biofeedback.

This paper describes an investigation into the developmental nature of the voice under training with and without the influence of real-time visually presented biofeedback. Two subjects who had not previously experienced any form of vocal training took six singing lessons. One was taught conventionally, while the other was taught with the aid of a system known as Acoustic and Laryngeal Biofeedback Enhancement Real Time (ALBERT). Real-time biofeedback was presented based upon measures of (i) larynx closed quotient (CQ), (ii) spectral amplitude in the singer's formant frequency band relative to the spectral amplitude of the full band (ratio), and (iii) both parameters combined in a manner based on previously observed correlations between them. Results indicate generally increased sound pressure levels (SPL) of acoustic output and generally consistent increases in the level of CQ and ratio across consecutive lessons for both subjects.

A survey of aphasia services in the United Kingdom.

A survey of the service available, in speech and language therapy departments, to adults with aphasia revealed that many districts in the United Kingdom are unable to fulfil the professional recommendations for the care of aphasic clients. Although individual 'good practice' criteria could be satisfied, only a minority of districts were able to provide a comprehensive service. Levels of staffing for the adult neurological caseload are variable and even, at best, hinder therapists in delivering the recommended standard of management to aphasic clients and their carers.

Integrated care pathways in multiple sclerosis rehabilitation: completing the audit cycle.

The rehabilitation of progressive neurological disorders, such as Multiple Sclerosis (MS) requires comprehensive, expert management which is demanding of both time and resources. Mechanisms to monitor and audit both process and outcome are therefore essential. Integrated care pathways (ICPs) which detail the expected interventions during a given episode of clinical care, provide such a mechanism. In this study three cohorts of patients (totalling 125 episodes) with clinically definite progressive MS underwent a rehabilitation programme audited through ICPs. The cohorts were similar in relation to disability and age. Variations (departures from the expected pathway) were documented for both the rehabilitation process and goal achievement. Duration of stay reduced from 28 days for the first cohort to 18 days for the third and there was greater multidisciplinary input and carer involvement over time. Goal achievement increased from 79% for the first cohort to 87% for the third and there was an increased emphasis on cognitive function and fatigue management in relation to goals set. ICPs provide an excellent mechanism for closing the audit loop and have the potential to play an important role in improving service provision in MS.

Stress and metabolic control in diabetes: psychosomatic evidence and evaluation of methods.

Psychosomatic research findings correlating psychologic stress with diabetic control fail as yet to provide valid conclusions. Investigators have presented many contradictory findings. The two major pathways by which stress could affect control, a) changes in compliance behavior, and b) a neurohumoral axis, have not been clearly distinguished from each other. The study of adolescent cohorts is associated with the problem of heterogeneity, limiting the application of results to other diabetic populations. Methods of determining diabetic control have been incomplete and the definition and measurement of stress have major inadequacies for the analysis of such a complex psychosomatic problem. Existing evidence is comprehensively reviewed and evaluated. The authors use a modified definition of stress to construct a stress scale specific to pregnant diabetics.