Analytical Issues Research Articles

A reanalysis of abstract contrasts and opacity in Bondu-so tongue root harmony

This paper explores a number of controversial consequences of previous abstract analyses of Bondu-so (Dogon) vowels and vowel harmony, particularly for the explanation of phonological opacity. Bondu-so has been characterised as displaying asymmetrically-patterning bidirectional harmony, a four-way [ATR] contrast on mid-vowel suffixes, and abstract [±ATR] contrasts on high and low vowels which display distinct phonological behaviours but which never surface, being absolutely neutralised (Hantgan & Davis 2012). I show that each of these unusual generalisations stems from the crucial mischaracterisation of underlying vowel contrasts and the direction of harmony in surface-ambiguous data. With a re-classification of the data, Bondu-so harmony patterns are characterisable as regular, derivationally transparent leftwards [RTR]-harmony with harmonically neutral non-contrastive high and low vowels – requiring no abstract contrasts, directional harmony asymmetries, or opacity of any kind. Following this non-abstract reanalysis, Bondu-so is revealed to be typologically and theoretically fully consistent with other harmony languages. This review of Bondu-so vowel patterns represents therefore an important contribution to the “abstractness controversy” – revealing important analytical and methodological issues in abstract approaches to phonological opacity.

Maximum depositional age estimation revisited

In a recent review published in this journal, Coutts et al. (2019) compared nine different ways to estimate the maximum depositional age (MDA) of siliclastic rocks by means of detrital geochronology. Their results show that among these methods three are positively and six negatively biased. This paper investigates the cause of these biases and proposes a solution to it. A simple toy example shows that it is theoretically impossible for the reviewed methods to find the correct depositional age in even a best case scenario: the MDA estimates drift to ever smaller values with increasing sample size. The issue can be solved using a maximum likelihood model that was originally developed for fission track thermochronology by Galbraith and Laslett (1993). This approach parameterises the MDA estimation problem with a binary mixture of discrete and continuous distributions. The ‘Maximum Likelihood Age’ (MLA) algorithm converges to a unique MDA value, unlike the ad hoc methods reviewed by Coutts et al. (2019). It successfully recovers the depositional age for the toy example, and produces sensible results for realistic distributions. This is illustrated with an application to a published dataset of 13 sandstone samples that were analysed by both LA-ICPMS and CA-TIMS U–Pb geochronology. The ad hoc algorithms produce unrealistic MDA estimates that are systematically younger for the LA-ICPMS data than for the CA-TIMS data. The MLA algorithm does not suffer from this negative bias. The MLA method is a purely statistical approach to MDA estimation. Like the ad hoc methods, it does not readily accommodate geological complications such as post-depositional Pb-loss, or analytical issues causing erroneously young outliers. The best approach in such complex cases is to re-analyse the youngest grains using more accurate dating techniques. The results of the MLA method are best visualised on radial plots. Both the model and the plots have applications outside detrital geochronology, for example to determine volcanic eruption ages.

Abstract IA23: Opportunities and lessons learned from the Cancer Research Network

Abstract Using health care systems data for research and care improvement is of intense interest. The now widespread availability of electronic health records (EHRs) holds great promise for population sciences cancer research. Founded in 1999, the Cancer Research Network (CRN) is a consortium of a dozen research groups affiliated with US integrated health care systems. CRN health care systems are pioneers in use of data systems to document and inform administrative and clinical aspects of health care. In addition to administrative (e.g., claims) data, the clinical databases of CRN health systems capture details of care that have generally not been available until the advent of EHRs. In most CRN health systems, such databases have been in use since at least the mid-1990s, with adoption of EHRs in the mid-2000s. CRN researchers developed the Virtual Data Warehouse (VDW) common data model to facilitate collaborative, multi-institution research. The VDW, with standardized data tables, variable names, and formats implemented at each participating research group, enables efficient multi-institution research collaborations. From a cancer research perspective, the VDW is also one of the only EHR-based common data models with tumor registry data of comparable quality to that of the SEER Program. Infusion medication data are also available in the VDW, and inclusion of results of clinical genetic and molecular tests is in development. The VDW is updated regularly, monthly or more frequently in most CRN institutions for most data domains. Advantages of conducting cancer research in the CRN setting include the ability to identify a “denominator” population, and the capture of primary and specialty care. Retention of health plan enrollees is high in CRN health systems, enabling longitudinal research. In most US health care settings, the population eligible to receive care cannot be identified, and data may be available for some, but not all, episodes of care. For example, tertiary-care cancer centers may have details on cancer treatment, but not information from primary care or other specialty care encounters. However, it is important to use caution because EHR data result from clinical encounters and associated activity and are not collected for research purposes; missingness is unlikely to be random and confounding by indication is an analytic and interpretational issue. Collaborative, efficient use of these data also requires navigating regulatory concerns. The federated nature of the VDW minimizes HIPAA-related privacy concerns, while agreed-upon human subjects and data use procedures facilitate collaborations. The CRN provides unparalleled opportunities for research across the full range of the cancer experience, from primary prevention to end of life, incorporating data from EHRs and other clinical and administrative databases. Use of these data and adherence to epidemiologic principles in the design of studies and their analysis and interpretation can greatly advance knowledge to decrease the burden of cancer. Citation Format: Lawrence H. Kushi, Jeffrey S. Brown, Diana S.M. Buist, Jessica Chubak, V. Paul Doria-Rose, Kathleen M. Mazor. Opportunities and lessons learned from the Cancer Research Network [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr IA23.

M-APSK Constellation Optimization in the Presence of Phase Reference Error

Considering the analytical issue of ${M}$ -ary amplitude phase-shift keying design in the presence of a phase reference error (PRE), we present a systematic optimization formulation to first minimize the error floor of the optimum detector, which decides on the number of signal points on each ring for all possible numbers of rings. Then with a closed-form minimum symbol error probability formulation, we are able to determine the optimal number of rings and the corresponding ring radii for specific PRE variance and average signal-to-noise ratio. This approach involves purely numerical computation without time-consuming simulations, and works well for all $M\geq 16 $ .

The Programmatic Action Framework: An empirical assessment

AbstractThis article starts with a discussion of the analytical issues of the Programmatic Action Framework (PAF); based on the hypothesis that small groups of individuals, sharing a similar analysis of a policy problem sustaining a common policy change program (including orientations, arguments, and instruments) giving them a collective identity, and behaving strategically as a collective actor, can be main drivers of policy change. We then present the methodological implications of the empirical analysis of such programmatic groups and policy change programs. The methodology of the Programmatic Action Framework combines tools coming from the sociology of elites (positional analysis, analysis of professional trajectories, relational analysis) and the sociology of the policy process. It was first applied in empirical researches on health insurance reforms in France and the United States since the 1980s, shedding the light on the key role of specialized policy elites (specialized senior civil servants in France, long‐term insiders in the United States). We conclude by stressing that, because of its systematic and encompassing empirical methodology, the Programmatic Action Framework can be used in a comparative way, in other policy sectors than health care.

Pb-Pb ages and initial Pb isotopic composition of lunar meteorites: NWA 773 clan, NWA 4734, and Dhofar 287.

Constraining the duration of magmatic activity on the Moon is essential to understand how the lunar mantle evolved chemically through time. Determining age and initial isotopic compositions of mafic lunar meteorites is a critical step in defining the periods of magmatic activity that occurred during the history of the Moon and to constrain the chemical characteristics of mantle components involved in the sources of the magmas. We have used the in situ Pb-Pb SIMS technique to investigate eight lunar gabbros and basalts, including six meteorites from the Northwest Africa (NWA) 773 clan (NWA 2727, NWA 2700, NWA 3333, NWA 2977, NWA 773, and NWA 3170), NWA 4734, and Dhofar 287A. These samples have been selected as there is no clear agreement on their age and they are all from the dominant low titanium chemical group. We have obtained ages of 2981 ± 12 Ma for NWA 4734 and 3208 ± 22 Ma for Dhofar 287. For the NWA 773 clan, four samples (the fine-grained basalt NWA 2727 and the three gabbros NWA 773, NWA 2977, NWA 3170) out of six yielded isochron-calculated ages that are identical within uncertainties and yielding an average age of 3086 ± 5 Ma. The age obtained for the fine-grained basalt NWA 2700 is not precise enough for comparison with the other samples. The gabbroic sample NWA 3333 yielded an age of 3038 ± 20 Ma suggesting that two distinct magmatic events may be recorded in the meteorites of the NWA 773 clan. The present study aims to identify and assess all potential issues that are associated with different ways to date lunar rocks using U-Pb–based methods. To achieve this, we have compared the new ages with the previously published data set. The entire age data set from lunar mafic meteorites was also screened to identify data showing analytical issues and evidence of resetting and terrestrial contamination. The data set combining the ages of mafic lunar meteorites and Apollo rocks suggests pulses of magmatic activity with two distinct phases between 3950 and 3575 Ma and between 3375 and 3075 Ma with the two phases separated by a gap of approximately 200 Ma. The evolution of the Pb initial ratios of the low-Ti mare basalts between approximately 3400 and 3100 Ma suggests that these rocks were progressively contaminated by a KREEP-like component.

Identification of analytical issues in method verification of SARS CoV-2 serology

Identification of analytical issues in method verification of SARS CoV-2 serology

Zirconium Interferences on the Detection of Silver Nanoparticles by Single Particle ICP-MS: Implications on Natural Water Analysis

The analysis of silver nanoparticle (NP Ag) by the single particle technique with argon plasma-coupled mass spectrometry (SP-ICP-MS) is an increasingly used analytical approach. The sensitive technique, distinguishing particle size distribution, allows working at concentrations similar to those found in environmental samples. The two natural Ag isotopes 107 and 109, with abundances of 52 and 48% respectively, have similar sensitivity in ICP-MS detection. However, it is common to encounter isobaric interferences in mass spectrometry, and the element silver is not an exception, as much with the 107 isotope as 109. For both isotopes, zirconium oxides present isobaric interferences, either 91Zr16O, 90Zr16O1H for the isotope 107 and the 92Zr16O1H for the 109. For surface water analysis by ICP-MS in regular technique, these interferences do not generally affect the analysis of total Ag concentrations as they can be then simply subtracted. On the other hand, detection of NP Ag was impacted by the interfering colloidal Zr. The analysis of Zr by the SP-ICP-MS technique of surface waters showed the presence of colloidal Zr, a random signal that cannot be simply subtracted from NP Ag signal. Our results showed that Zr colloids are effectively interfering with the NP Ag assays by SP-ICP-MS technique where interferences translated into a false positive. We proposed a calculation to evaluate a confidence threshold defining the maximum size that the false positives induced by Zr particles have on the silver particle detection. The analytical issue related to isobaric interferences from the naturally occurring colloidal Zr was attenuated by the use of the 109 isotope in the Ag particle detection, limiting false positive detections and improving the reliability of NP Ag measurements in natural waters. Therefore, more specific detection of NP Ag in surface waters that naturally contain Zr colloids can be accomplished.

A miner's perspective on Pb isotope provenances in the Western and Central Mediterranean

The conventional approach to ore provenance studies of ancient silver coins and artifacts has been to first analyze and then try to match them to published data about mining districts, a difficult task given our incomplete knowledge of these. While literary sources are useful to identify possible provenances, they potentially bias interpretations proper because of a variety of limitations of their time. Archeological evidence in the form of mining shafts, galleries, spoil heaps, and tools also provides a tangible and reliable record of mining, but dating such activity can be problematic and the record is inconsistent. Here we propose a new approach driven by Pb isotopic data rather than numismatic groups. Statistical analysis of Pb isotopic data is used to identify ore-defined isotopic clusters. This new method is based on an algorithm that predicts the number of isotopic clusters necessary to fulfill the simple condition that variance within isotopic clusters is minimized whereas inter-cluster variance is maximized. Since each cluster reflects a discrete geological episode within a particular environment broadly datable to a specific Pb model age, it can be identified as a potential source exploited by ancient miners. We explore the potential of this method in two examples using data from coins and ores respectively. In the first example, Roman Republican silver coins form three ‘end-member’ clusters sourced in mining districts with Cenozoic, Mesozoic, and Paleozoic Pb model ages. The example demonstrates how sources of silver used to mint coinage of the Roman Republic shifted within 50 years of the end of the Second Punic War in 201 BCE. In the second example using Aegean galena samples, Pb isotopes distinguish components with model ages datable to the Hercynian basement, the recent Aegean tectonic province, and Cyprus, noting that significant silver mining districts may remain unidentified in either Spain or the Aegean world. We further clarify a number of potential analytical issues and advocate that users of Pb isotopes for tracing archeological artifacts measure all four lead isotopes and inspect the 12 proposed isotope combinations in order to select those that provide the best representation of the data. We also emphasize that full advantage should be taken of the geologically informed parameters (model age and Th/U/Pb relationships) to identify the geological context of metal sources.

The Validation of Analytical Assays for Biopharmaceutical Studies

The information required for an adequate analytical method validation for either in vitro or in vivo biopharmaceutical studies is discussed in this article. The most commonly applied assay parameters: accuracy, precision, detection limit, specificity, selectivity, calibration linearity or nonlinearity, stability, recovery, reproducibility and repeatability are carefully defined along with some recommendations required for assessing data acceptability arrived at the conference on Analytical Methods Validation. Though more specific analytical issues concerning microbiological assay radioimmunoassay and stereoisomer assay were not examined, this article should provide good guidance to pharmaceutical chemists to properly perform analytical method validation and carry out routine analysis.

Simultaneous analysis of potassium and ammonium ions in the vitreous humour by capillary electrophoresis and their integrated use to infer the post mortem interval (PMI).

Post-mortem changes of ions in the body fluids have been proposed as an objective tool for inferring the time of death. In particular, the post-mortem increase of potassium concentrations in the vitreous humour has gained great attention in the literature. On the other hand, ammonium, another ion released in post-mortem processes, has received much less attention, potentially due to unresolved analytical issues using current clinical chemistry methods. This paper presents an application of a new analytical approach based on capillary electrophoresis providing the simultaneous analysis of potassium and ammonium ions in the vitreous humour. In addition, to assess the consistency of the post-mortem increase of ammonium concentrations in the vitreous humour, the determination of this ion in the vitreous humour of the two eyes of the same body at the same post-mortem interval has been verified. Vitreous humour was collected from 33 medico-legal cases where the time of death was known exactly. Prior to analysis, all samples were diluted 1:20 with a 40 μg/mL solution of BaCl2 (internal standard). In the study of the variability of the ammonium concentration between the two eyes, no statistically significant differences were found, supporting the hypothesis of an even post-mortem increase of the ion concentrations in this particular biological fluid. Significant correlations of potassium and ammonium ions with the post-mortem interval were found, with r2 of 0.75 and 0.70, respectively.

Physical activity, a modulator of aging through effects on telomere biology.

Aging is a complex process that is not well understood but involves finite changes at the genetic and epigenetic level. Physical activity is a well-documented modulator of the physiological process of aging. It has been suggested that the beneficial health effects of regular exercise are at least partly mediated through its effects on telomeres and associated regulatory pathways. Telomeres, the region of repetitive nucleotide sequences functioning as a “cap” at the chromosomal ends, play an important role to protect genomic DNA from degradation. Telomeres of dividing cells progressively shorten with age. Leucocyte telomere length (TL) has been associated with age-related diseases. Epidemiologic evidence indicates a strong relationship between physical activity and TL. In addition, TL has also been shown to predict all-cause and cardiovascular mortality. Experimental studies support a functional link between aerobic exercise and telomere preservation through activation of telomerase, an enzyme that adds nucleotides to the telomeric ends. However, unresolved questions regarding exercise modalities, pathomechanistic aspects and analytical issues limit the interpretability of available data. This review provides an overview about the current knowledge in the area of telomere biology, aging and physical activity. Finally, the capabilities and limitations of available analytical methods are addressed.

Therapeutic monitoring of antiepileptic drugs: Recommendations to improve care of patients with epilepsy in the Palestinian practice

BackgroundTherapeutic drug monitoring (TDM) can play a major role in optimizing pharmacotherapy of epilepsy. This study was conducted to explore views and opinions of clinicians who care for patients with epilepsy (PWE) in Palestine and to develop consensus-based recommendations with regard to importance, justification, technical, and analytical issues of TDM of antiepileptic drugs (AEDs). MethodsThe study was conducted in three phases: (1) the published literature was thoroughly searched for an initial list of items relevant to TDM of AEDs, (2) the list was supplemented by items provided by key experts (n = 8) through semi-structured in-depth interviews, (3) views and opinions of clinicians (n = 20) on TDM of AEDs were explored, and (4) a two-round Delphi technique was followed among a panel of experts (n = 27) to develop consensus-based recommendations to guide TDM of AEDs in Palestine. ResultsConsensus was achieved on items related to importance (8 items) of TDM of AEDs, clinical justifications of TDM of AEDs (19 items), guidelines for optimal TDM of AEDs (11 items), TDM of some AEDs (21 items), TDM practice (24 items), and some technical and analytical issues in TDM of AEDs (13 items). ConclusionConsensus-based recommendations that might be used in guiding TDM of AEDs in Palestine were developed. Future studies are still needed to investigate if these consensus-based recommendations can improve healthcare of PWE in Palestine.

A new opening for the tricky untargeted investigation of natural and modified short peptides

Short peptides are of extreme interest in clinical and food research fields, nevertheless they still represent a crucial analytical issue. The main aim of this paper was the development of an analytical platform for a considerable advancement in short peptides identification. For the first time, short sequences presenting both natural and post-translationally modified amino acids were comprehensively studied thanks to the generation of specific databases. Short peptide databases had a dual purpose. First, they were employed as inclusion lists for a suspect screening mass-spectrometric analysis, overcoming the limits of data dependent acquisition mode and allowing the fragmentation of such low-abundance substances. Moreover, the databases were implemented in Compound Discoverer 3.0, a software dedicated to the analysis of short molecules, for the creation of a data processing workflow specifically dedicated to short peptide tentative identification. For this purpose, a detailed study of short peptide fragmentation pathways was carried out for the first time. The proposed method was applied to the study of short peptide sequences in enriched urine samples and led to the tentative identification more than 200 short natural and modified short peptides, the highest number ever reported.

Angiotensin Receptor Neprilysin Inhibitors-2019 Update.

An abundance of new data regarding the use of the novel drug compound sacubitril/valsartan in chronic heart failure (CHF) patients is published every year since the initial publication of the PARADIGM-HF study in 2014. This review summarises the most recent evidence (2019 and onwards) of sacubitril/valsartan in CHF patients as well as provides a critical appraisal of these data. New data are grouped in categories such as real-world data, randomised controlled trials, surrogate end-points, cost-effectiveness, use of sacubitril/valsartan as an anti-hypertensive treatment, effect on diuretic dosing and implementation of this novel compound in other populations. This review of recent literature identified important messages such as early initiation during index hospitalisation or immediately post-discharge, barriers against implementation of this novel treatment modality, analytical issues regarding measuring natriuretic peptides in patients under treatment and extrapolated use of sacubitril/valsartan in other than PARADIGM-HF populations. This update may serve as a very helpful evidence-based resource for practising clinicians, future research planning and health-related policy makers.

Standardizing measurement in psychological studies: On why one second has different value in a sprint versus a marathon.

Here we highlight the importance of considering relative performance and the standardization of measurement in psychological research. In particular, we highlight three key analytic issues. The first is the fact that the popular method of calculating difference scores can be misleading because current approaches rely on absolute differences, neglecting what proportion of baseline performance this change reflects. We propose a simple solution of dividing absolute differences by mean levels of performance to calculate a relative measure, much like a Weber fraction from psychophysics. The second issue we raise is that there is an increasing need to compare the variability of effects across studies. The standard deviation score (SD) represents the average amount by which scores differ from their mean, but is sensitive to units, and to where a distribution lies along a measure even when the units are common. We propose two simple solutions to calculate a truly standardized SD (SSD), one for when the range of possible scores is known (e.g., scales, accuracy), and one for when it is unknown (e.g., reaction time). The third and final issue we address is the importance of considering relative performance in applying exclusion criteria to screen overly slow reaction time scores from distributions.

A COMPARATIVE STUDY ON THE POSSIBILITY OF FORMING A SOLE CORPORATION IN THE IRANIAN AND US LAWS

Although the new Bill of commercial law and prevailing Laws in the European and American societies indicate the possibility of the possibility of forming a sole corporation, but it is not possible to form a personal firm under existing regulations, especially the existing commercial law. In the essay, by using from a comparative study on US commercial law and through analytical issues, we point out that, in the analytical view (not legal), formation of such corporations not only does not face any obstacles but also can be beneficial in various ways. So we present benefits of Sole Corporation and finally discuss the management and liquidation of these Corporations

Setup of an Extraction Method for the Analysis of Carotenoids in Microgreens.

Microgreens are gaining increasing interest as a potential functional food due to their relevant contents of micronutrients and bioactive compounds, including carotenoids. Nevertheless, the analysis of carotenoids is inherently difficult, due to their thermal and chemical susceptibility, as well as to their varying polarity. From this point of view, extraction is the most critical step, compared to chromatographic separation and detection. Thus, the reliability of data on carotenoids should be guaranteed by a constant focus on analytical issues, with appropriate adaptations to each sample matrix. In this research, a specific extraction procedure for the analysis of carotenoids in microgreens was developed. Solvent composition, extraction time, solvent/sample ratio, and repeated extractions were evaluated. The obtained protocol showed recovery of 97.2%, limits of quantitation of 5.2 μg·g−1 for lutein and 15.9 μg·g−1 for β-carotene, as well as intra-day mean repeatability of 5.7% and inter-day mean repeatability of 4.7%.

Economic Evidence in Antitrust: Defining Markets and Measuring Market Power

This paper addresses an important aspect of the interdisciplinary collaboration between law and economics: the use antitrust courts can and should make of empirical industrial organization economics, in light of the expansion of empirical knowledge generated during the last few decades. First we show how courts can apply what economists have learned about identification of alternative theories of industry structure and firm strategy to the problems of defining markets and determining whether market power has been exercised. We emphasize that the same analytic issues arise regardless of whether the evidence on these concepts is quantitative or qualitative. Second we show how courts can adopt a strategy employed in the research literature, by exploiting generalizations across closely related industries to help evaluate evidence and resolve cases. We also discuss ways of increasing the institutional capacity of the judicial system to make use of these two bodies of economic learning. These include a possible limited role for neutral economic experts in litigation, and a role for the antitrust enforcement agencies in identifying and codifying relevant generalizations about industries from the empirical economic literature to make that learning available to courts.

Sobre sensacionalismo, violencia y conocimiento académico

This essay interrogates methodological, analytical and representational issues that continue to challenge scholars addressing bellicose violence: Is it ethical to write about terror, pain and despair from afar? Can sensationalism ever be justified in analyses of bellicose violence? What kind of silences might we allow for? These questions are explored in relation to necropolitical Mexico, drawing from empirical research with musicians commissioned to write narco rap, producers and consumers of rap del barrio, and hip hop artists protesting the disappearances, homicides, systematic violence and impunity enjoyed by criminal organisations and state institutions alike.