Bivariate Frequency Distribution Research Articles

Prevalence and Patterns of Elderly Abuse in Family Environment: A Cross-Sectional Study of Hetauda Sub-Metropolitan City

The primary goal of this study is to investigate the relationship between elderly people's socioeconomic characteristics and the average rank of elderly abuse patterns. The study was primarily concerned with quantitative research and employed a cross-sectional survey method. From a population of 16,489 in Hetauda Sub-metropolitan City, 412 elderly people were chosen at random. To collect data, face-to-face interviews with structured interview schedules were used. A pilot survey was conducted to ensure validity and reliability in data. In the study, data was analysed using univariate and bivariate frequency distributions, as well as non-parametric tests. According to the study, the prevalence of overall abuse was 35.90% and psychological abuse was observed high among others. The most common types of abuse were moderate psychological abuse (43.8%), neglect (60.5%), and overall abuse (57.8%). Mild economic abuse accounted for 60%, while other types of abuse accounted for 79.4%. The study also looked at the link between abuse and gender, and found statistically insignificant differences (p>0.05). However, there was a significant difference (p<0.05) in the prevalence of psychological and overall abuse based on property ownership, whereas other patterns revealed no significant differences (p>0.05). Except for psychological and overall abuse, dependency status had no significant impact on the occurrence of elder abuse patterns (p>0.05). Except for certain participants, the prevalence of elderly abuse was high. Psychological, economic, and overall abuse varied significantly by age group, but neglect and other forms did not (p>0.05). Except for psychological abuse, family size and income level were found to have significant differences in abuse patterns. The study's findings highlight the importance of targeted interventions and policies to prevent and address elder abuse, particularly among vulnerable populations. To address the identified disparities, comprehensive measures that prioritise the well-being and safety of vulnerable elders must be implemented.

Aircraft Observations of Turbulence in Cloudy and Cloud‐Free Boundary Layers Over the Western North Atlantic Ocean From ACTIVATE and Implications for the Earth System Model Evaluation and Development

AbstractThis study examines boundary layer turbulence derived from high temporal resolution meteorological measurements from 40 research flights over the western North Atlantic Ocean during the 2020 deployments of ACTIVATE. Frequency distributions of various turbulent quantities reveal stronger turbulence during the winter deployment than in summer and for cloud‐topped than in cloud‐free boundary layers during the summer deployment. Maximum turbulence kinetic energy (TKE) is most often within cloud from observations in winter and summer, whereas it is mostly below cloud in both seasons by a global model turbulence parameterization. Bivariate frequency distributions are consistent with the bivariate Gaussian probability distribution functions assumed for the closure of higher‐order turbulence/shallow convection parameterizations used by some global models. Turbulence simulated by the Community Atmosphere Model version 6 and the Energy Exascale Earth System Model Atmosphere Model version 2 using such parameterizations is not as strong as observed, with more TKE going into vertical wind perturbations rather than into zonal wind perturbations as observed, suggesting that the treatment of turbulence in Earth system models still needs to be further improved.

How to discriminate non-small cell lung cancer (NSCLC) cases from an Italian administrative database? A retrospective, secondary data use study for evaluating a novel algorithm performance

ObjectivesTo evaluate an algorithm developed for identifying non-small cell lung cancer (NSCLC) candidates among patients with lung cancer with a diagnosis International Classification of Diseases: ninth revision (ICD-9) 162.x code...

Determinants Analysis of the Incidence of Stunting in Children 1-2 Years

Stunting become a serious problem in Indonesia because it was associated with increased risk of morbidity and mortality, suboptimal brain development that delayed motor development and mental retardation. In fulfillment of family nutrition required a good knowledge about balanced nutrition. This study was an observational study with case control study design, The sampling technique used purposive sampling so that the respondents obtained were 30 toddlers at 4 posyandu. Analysis of the data used for bivariate frequency distribution, while multivariate logistic regression. Result: Obtained a significant relationship with the incidence of stunting, namely the mother's education level (ρ: 0.03; 0.621), family economy (ρ: 0.03; OR: 0.158), mother's height (ρ: 0.01: OR: 12.045), while the sex of children under five did not have a significant relationship with the incidence of stunting, namely ρ: 0.11> α0.05. The incidence of stunting in children aged 1-2 years is influenced by the mother’s education, height of parents especially mother’s, and family economic status. Mothers must know about types of food that have high nutritional value at low prices so that the nutritional adequacy of the family is fulfilled.

The effects of magnesium sulphate on haemodynamic stress response to pneumoperitonium in laparoscopic cholecystectomy: a double blinded randomised controlled study

Background: To study the effect of intravenous magnesium sulphate on hemodynamic response to pneumoperitoneum during laparoscopic cholecystectomy and to study the side effects of the drug of any.Methods: Patients were randomly allocated into two groups of 40 each. Automated NIBP, Heart rate, Nausea, headache was noted. Magnesium ion concentration was measured. Chi square test was used to test the association between different study variables under study. Corrected test was used in case of any one of the cell frequency was found less than 5 in the bivariate frequency distribution. Fisher’s Exact Test was also used in the case where the test could not be applied. Test of proportion (Z-test) was used to test the significant difference between two proportions. t-test was used to test the significant difference between means. P≤0.05 was considered statistically significant.Results: Patients’ characteristics were comparable in both groups. Most data related to surgery and anaesthesia were comparable in both groups. The MAP of group N (control) was significantly higher than that of group M throughout surgery (P5,P10,P20,P30, and at extubation) except at baseline and at the time of PP (P0). The MAP is better maintained in M group. Usage of GTN in the control group was significantly higher. HR of the control group was significantly higher after 20 min (P20) of pneumoperitoneum and after extubation. There was significantly more incidence of nausea and vomiting in the control group.Conclusions: Use of magnesium sulphate just before pneumoperitoneum is very useful for attenuating haemodynamic alterations to pneumoperitoneum and the requirement of antihypertensive GTN is significantly much less compared to the control group during laparoscopic surgery without increasing any adverse outcome.

Is the ‘reverse onion skin’ phenomenon more prevalent than we thought during intramuscular myoelectric recordings from low to maximal force outputs?

There are isolated instances in the literature that suggest the ‘onion skin’ phenomenon is not always present. That is, newly recruited high threshold motor units (MU) have higher discharge rates than previously recruited low threshold MUs. Therefore, the purpose of this paper was to investigate the presence of the ‘onion skin’ phenomenon in a large sample of intramuscular myoelectric recordings from low to maximal force outputs. Forty-eight participants performed rapid isometric dorsiflexion contractions at 20, 40, 60, 80 and 100 % MVC while intramuscular electrical activity was recorded. A bivariate frequency-distribution of the motor unit discharge rate and motor unit action potential peak-to-peak (P-P) amplitude was assessed. There was a significant difference in bivariate frequency-distribution across force levels (D’s = 0.1083−0.3094, p’s < 0.001). Newly recruited high threshold MUs did have lower discharge rates, but there was an increase in the presence of high threshold, large P-P amplitude MUs with higher discharge rates than lower threshold MUs (reverse onion skin) during the stable portion of the force output. The recruitment of high threshold MUs with higher discharge rates decreased the level of common drive from the cross-correlation (Rxy) = 0.79 at 20 % MVC to Rxy = 0.68 at 100 % MVC (p < 0.01), but it remained high. As the interference pattern becomes more complex with the recruitment of more motor units at higher force outputs, intramuscular electrodes may be more discriminating while recording motor unit activity leading to the identification of both the ‘reverse onion skin’ and ‘onion skin’ phenomenon being present.

Citizen-Centered Mobile Health Apps Collecting Individual-Level Spatial Data for Infectious Disease Management: Scoping Review.

BackgroundThe novel coronavirus SARS-CoV-2 rapidly spread around the world, causing the disease COVID-19. To contain the virus, much hope is placed on participatory surveillance using mobile apps, such as automated digital contact tracing, but broad adoption is an important prerequisite for associated interventions to be effective. Data protection aspects are a critical factor for adoption, and privacy risks of solutions developed often need to be balanced against their functionalities. This is reflected by an intensive discussion in the public and the scientific community about privacy-preserving approaches.ObjectiveOur aim is to inform the current discussions and to support the development of solutions providing an optimal balance between privacy protection and pandemic control. To this end, we present a systematic analysis of existing literature on citizen-centered surveillance solutions collecting individual-level spatial data. Our main hypothesis is that there are dependencies between the following dimensions: the use cases supported, the technology used to collect spatial data, the specific diseases focused on, and data protection measures implemented.MethodsWe searched PubMed and IEEE Xplore with a search string combining terms from the area of infectious disease management with terms describing spatial surveillance technologies to identify studies published between 2010 and 2020. After a two-step eligibility assessment process, 27 articles were selected for the final analysis. We collected data on the four dimensions described as well as metadata, which we then analyzed by calculating univariate and bivariate frequency distributions.ResultsWe identified four different use cases, which focused on individual surveillance and public health (most common: digital contact tracing). We found that the solutions described were highly specialized, with 89% (24/27) of the articles covering one use case only. Moreover, we identified eight different technologies used for collecting spatial data (most common: GPS receivers) and five different diseases covered (most common: COVID-19). Finally, we also identified six different data protection measures (most common: pseudonymization). As hypothesized, we identified relationships between the dimensions. We found that for highly infectious diseases such as COVID-19 the most common use case was contact tracing, typically based on Bluetooth technology. For managing vector-borne diseases, use cases require absolute positions, which are typically measured using GPS. Absolute spatial locations are also important for further use cases relevant to the management of other infectious diseases.ConclusionsWe see a large potential for future solutions supporting multiple use cases by combining different technologies (eg, Bluetooth and GPS). For this to be successful, however, adequate privacy-protection measures must be implemented. Technologies currently used in this context can probably not offer enough protection. We, therefore, recommend that future solutions should consider the use of modern privacy-enhancing techniques (eg, from the area of secure multiparty computing and differential privacy).

A novel approach for voltage sag representation in a chemical industry: A case study

AbstractVoltage sag is a major Power Quality issue which may occur at every possible load point. In the industrial sector, its impact is particularly prominent at it is directly related to financial losses. To eliminate or, at least, mitigate voltage sag, the first, and the most crucial, step is to identify the portions of the network which are vulnerable to voltage sag. Therefore, a novel approach is presented in this article to identify the areas within the network, which are more prone to voltage sag. An impedance matrix‐based model followed by Monte Carlo Simulation (MCS) technique is used for the assessment of the voltage sag. This MCS technique is implemented to simulate the number, type, and locations of faults randomly within the system. Then, voltage sag data are collected, and using Bivariate Frequency Distribution, a graphical representation of voltage sag prone buses is developed, which named Voltage Sag Map. The effectiveness of the proposed approach is validated by adopting an industrial distribution system as a case study in this article.

Pelayanan dan Fasilitas Kesehatan, Biaya Persalinan, dan Kebijakan di Tempat Bersalin Mempengaruhi Ibu Dalam Memilih Tempat Bersalin di Kelurahan Kemiri Muka, Kecamatan Beji, Depok

One indicator of a country's health status is the maternal and infant mortality rate. 52.4% of mothers in Indonesia have access to maternal services. Maternal Mortality Rate (MMR) in Indonesia in 2008 according to the Demographic Health Survey of Indonesia is 307 per 100,000 live births, its far from the supposed target of 110 per 100,000 live births. The general objective of this study was to determine the factors associated with mother's decision when choosing a birth place, including the choice of giving birth. The factors that affect mother's decision when choosing a birth place are characteristic of the respondents and distance delivery and home place. Research sample is mothers residing in RW 03 Kelurahan Kemiri Muka - Depok totaling 125 people. This study uses a questionnaire and return rate = 100%. This study uses cross sectional data analysis using univariate and bivariate frequency distribution using the chisquare test. The results showed that there was a significant relationship between respondent’s education (p-value = 0.009; = 0.05), the husband's income &amp; (pvalue = 0.046; = 0.05), and health facilities (p -value = 0.033; = 0.05) with a choice of place of birth.

Vertical relief facilitates spatial segregation of a high density large carnivore population

Quantifying the distribution and size of home ranges is critical for understanding animal spatial dynamics. This is particularly important for large carnivores in fragmented landscapes. Most studies that estimate home range consider only a bivariate frequency distribution represented by a two‐dimensional planimetric surface. The underlying assumption of these approaches is that the animals inhabit landscapes that are completely flat. Of course, this is rarely the case. Here we investigated the influence of vertical relief and three‐dimensional landscape features on the home range patterns of a high density carnivore. Via GPS telemetry‐tracking of a population of Persian leopards Panthera pardus saxicolor (n = 6), and globally‐available digital elevation models (DEMs), we calculated the surface area of home ranges in comparison to traditional planimetric estimates. We also investigated predation patterns of leopards across elevation gradients using GPS location data and kill site analysis. The topographic measurements exceeded planimetric estimates by up to 38% which suggests that planimetric modeling underestimates home range size, particularly when animals inhabit variable terrain. We also observed that resident leopards exhibit significant altitudinal partitioning of predation, suggesting that leopards that have overlapping home ranges may still utilize exclusive hunting territories. We discuss the ways in which planimetric approaches may be underestimating aspects of animal ranging behavior and ecology. We conclude that topography should be considered, not as an ancillary metric, but as an important aspect of home range calculation. Our approach can enhance understanding of spatial requirements, population density, intra‐guild sympatric competition and conflict management of large felids inhabiting rugged landscapes.

Pemakaian Alat Kontrasepsi Suntik Berhubungan dengan Gangguan Menstruasi pada Akseptor KB di Wilayah Kerja Puskesmas Lubuk Buaya Padang Tahun 2018

Kontrasepsi adalah upaya untuk mencegah terjadi kehamilan. Menurut World Health Organization (WHO) penggunaan kontrasepsi suntik sebesar 38,35%, di Indonesia sebanyak 58%. Puskesmas Lubuk Buaya merupakan angka cakupan KB baru dan KB aktif dari 21766 orang pasangan usia subur (PUS) yang menggunakan jenis kontrasepsi suntik sebanyak 7.028 (42,3%). Penggunaan kontrasepsi suntik di Puskesmas Lubuk Buaya Padang sebanyak 9.689 (30,29%) aseptor.Tujuan penelitianini adalah untuk mengetahui hubungan pemakaian alat kontrasepsi suntik dengan gangguan menstruasi pada akseptor KB di Wilayah Kerja Puskesmas Lubuk Buaya Padang Tahun 2018. Jenis penelitian analitik dengan desain Cross Sectional. Penelitian telah dilakukan di Wilayah Kerja Puskesmas Lubuk Buaya Padang Populasi penelitian ini adalah seluruh Akseptor aktif dengan suntik sebanyak 601orang, jumlah sampel sebanyak 86 orang, dengan cara Proportional Sampling. Data yang diperoleh dianalisa secara univariat dengan distribusi frekuensi dan bivariate dengan uji statistic Chi-Square. Hasil penelitian didapatkan bahwa dari 86 responden, 69,8% akseptor KB menggunakan kontrasepsi suntik , 60,5% akseptor KB mengalami gangguan menstruasi. Uji Chi-Square terdapat hubungan yang bermakna antara pemakaian alat kontrasepsi suntik dengan gangguan menstruasi, dengan nilai p value 0,003. Disarankan penelitian ini dapat dijadikan bahan informasi dalam upaya meningkatkan pelayanan.&#x0D; &#x0D; Kata kunci :Pemakaian Kontrasepsi Suntik, GangguanMenstruasi

EFEKTIFITAS TERAPI AKTIVITAS KELOMPOK (TAK) STIMULUS PERSEPSI TERHADAP HALUSINASI PADA PASIEN SKIZOFRENIA PARANOID DI RSJKO SOEPRAPTO BENGKULU TAHUN 2010

The most frequent type of schizophrenia is paranoid schizophrenia, whereas in patients with schizophrenia have common criteria and experiencing hallucinations or delusions (Suseno, 2001). Incidence of paranoid schizophrenia in RSJKO Soeprapto Bengkulu in 2008 was (58.84%) and in 2009 was (68.44%) (Medical Record, RSJKO Soeprapto, 2010). Paranoid schizophrenic with hallucinations and panic can act led to the occurrence of suicide or homicide. (Suseno, 2001). Nursing actions appropriate to address a group hallucination is a therapeutic group activities (TAK) (Siahaan HB, 1999). The purpose of research is known influence of group activity therapy (TAK) stimulation perception to hallucinations in RSJKO Soeprapto Bengkulu in 2010.Design research is an experiment: pre and post test. The population was all patients with paranoid schizophrenia who were treated at RSJKO hallucinations Soeprapto Bengkulu, on July 1 to August 31 in 2010, totaling 38 people. Purposive sampling technique with sampling. Analyses were performed by univariate and bivariate frequency distribution with one sample.T test, with α = 5%.The results were: ther’s a relationship bof group activity therapy (TAK) stimulation perception: recognition hallucinations (p = 0.00), controlling hallucinations (p = 0.00), preparation of the schedule of events (p = 0.01), the way drinking either drug (p = 0.00).It is hoped that nurses in RSJKO more intensified activities group activity therapy (TAK) regularly, at least once a week for paranoid schizophrenia patients with hallucinations. In order to speed up eliminating hallucinations and shorten the lengthofthepatient.

Co-evolution of hydrological components under climate change scenarios in the Mediterranean area

The Mediterranean area is historically characterized by high human pressure on water resources. Today, while climate is projected to be modified in the future, through precipitation decrease and temperature increase, that jointly and non-linearly may affect runoff, concerns about water availability are increasing. For these reasons, quantitative assessment of future modifications in the mean annual water availability are important; likewise, the description of the future interannual variability of some hydrological components such as runoff and evapotranspiration are highly wished for water management and ecosystems dynamics analyses. This study investigates at basin spatial scale future runoff and evapotranspiration, exploring their probability density functions and their interdependence as functions of climatic changes. In order to do that, a parsimonious conceptual lumped model is here used. The model is forced by different future climate scenarios, generated through a weather generator based on a stochastic downscaling of an ensemble of General Circulation Models (GCMs) realizations. The use of the adopted hydrological model, under reliable stochastic future climate scenarios, allows to project future values of evapotranspiration and runoff in a probabilistic framework and, at the same time, the evaluation of their bivariate frequency distributions for changes through the Multivariate Kernel Density Estimation method. As a case study, a benchmark Mediterranean watershed has been proposed (Imera Meridionale, Italy). Results suggest a radical shift and shape modification of the annual runoff and evapotranspiration probability density functions. Possible implications and impacts on water resources management are here addressed and discussed.

Spatial Characterization and Bivariate Frequency Analysis of Precipitation and Runoff in the Upper Huai River Basin, China

The variability of the relationship between precipitation and runoff is of vital importance to study the characteristics of regional water cycle and water resource management and planning. In this study, in order to explore the relationship between precipitation and runoff of the different hydrological patterns, the analysis of bivariate precipitation and runoff distributions and the simultaneous occurrence probability was analyzed by employing the Archimedean copula, based on the monthly runoff and precipitation data during 1960 ~ 2000 in the upper Huai river basin, China. The results indicated that: (I) the study region could be classified into four hydrological patterns, namely the Huai river valley zone, Huaibei plain zone, Huainan mountain zone and Huaibei mountain zone, with Xixian, Zhuanqiao, Meishan and Zhaopingtai as the maximal loading subbasin respectively. (II) There were positive dependence structure between precipitation and runoff in the study area, and the bivariate frequency distributions could be fitted best by the Gumbel-Hougaard copula. (III) The simultaneous occurrence probability of bivariate drought events was remarkable higher than that of corresponding classification of bivariate flood events; besides, the simultaneous occurrence probability of bivariate extreme events was maximum in the Huainan mountain zone, followed by the Huai river valley zone and Huaibei mountain zone, while that was minimum in the Huaibei plain zone. These results would be of essential guiding significance for water resource management and planning, flood and drought control and layout optimization of water conservancy projects in the study region.

ENSEMBLES-based assessment of regional climate effects in Luxembourg and their impact on vegetation

Projected future regional climate changes in Luxembourg are assessed based on a six-member ensemble of regional climate models (RCM) from the ENSEMBLES project. The key aspects are projected changes in air temperature and their impacts on vegetation. Up to now, there have been only few assessments of future climate conditions for Luxembourg. As agriculture is the dominant land use in Luxembourg, possible effects on crops and vegetation in general are highly relevant. Different RCMs at 25 km spatial and a daily temporal resolution, ranging from 1961 to 2100 based on the SRES A1B emission scenario are used. To reduce systematic biases in the RCM-derived time series, a bias correction is applied. Multi-model annual mean temperatures are projected to increase by 3.1 °C between the reference time span (1961 to 1990) and the far future (2069 to 2098). Clear change signals are found in seasonal bivariate frequency distributions of air temperature and precipitation. Derived impacts are an elongation of the thermal vegetation period by 6.2 days per decade due to an earlier onset in spring; growing degree day sums show a substantial increase leading to potentially better growth conditions; the earlier onset of the vegetation period causes an increase in late frost risk, especially in the near future (2021 to 2050) projections compared to the reference period.

LOCATING THE STRUCTURAL ZEROS FOR INTERNAL ANCHOR TESTS: INCLUDING THE CASE OF ROUNDED FORMULA SCORES

There are test-equating situations in which it may be appropriate to fit a loglinear or other type of probability model to the joint distribution of a total score on a test and a score on part of that test. For anchor test designs, this situation arises for internal anchor tests, which are embedded within the total test. Similarly, a part-whole relationship arises between two scores when a few test items are dropped from a test and a single group design is used to equate the scores of the full test to the part that remains after those items are deleted. In these part-whole situations, the resulting bivariate frequency distribution will exhibit structural zeros due to the fact that some scores on the total test are impossible for specific values on the partial test. Without knowing where the structural zeros are, it is impossible to distinguish them from zero frequencies that are simply due to size of the sample (i.e., sampling zeros). When probability models are estimated for these joint distributions, it is usual to require the models to assign positive probability to the sampling zeros but to avoid assigning positive probability to the structural zeros. To do this, it is important to be able to locate where the structural zeros are in the bivariate distribution. When the scores on the tests are consecutive integers, it is easy to determine the location of the structural zeros. This report gives a solution to the problem of locating the structural zeros that arise for a class of bivariate distributions that includes both number-right scores and formula scores that have been rounded to integer values. The result for rounded formula scores is a simple alteration of the case where all the scores are consecutive integers.

Univariate and Bivariate Loglinear Models for Discrete Test Score Distributions

The well-developed theory of exponential families of distributions is applied to the problem of fitting the univariate histograms and discrete bivariate frequency distributions that often arise in the analysis of test scores. These models are powerful tools for many forms of parametric data smoothing and are particularly well-suited to problems in which there is little or no theory to guide a choice of probability models, e.g., smoothing a distribution to eliminate roughness and zero frequencies in order to equate scores from different tests. Attention is given to efficient computation of the maximum likelihood estimates of the parameters using Newton's Method and to computationally efficient methods for obtaining the asymptotic standard errors of the fitted frequencies and proportions. We discuss tools that can be used to diagnose the quality of the fitted frequencies for both the univariate and the bivariate cases. Five examples, using real data, are used to illustrate the methods of this paper.

Prevalence and patterns of major depressive disorder in the United States labor force

BACKGROUND AND AIMS OF THE STUDY: In this paper, we identify the 12-month and lifetime prevalence of major depressive disorder in and out of the labor force, and among the employed and unemployed. We examine whether prevalence by labor force and employment status varies by gender and over the life cycle. Finally, we examine whether people can "recover" from depression with time by identifying patterns of labor force participation and employment as time since most recent episode passes. METHODS: We examine data collected as part of the National Comorbidity Survey, a survey representative of the population of the United States designed to identify the prevalence of major mental illnesses. The National Comorbidity Study identified cases of major depression via the Composite International Diagnostic Interview. Using these data, we estimate univariate and bivariate frequency distributions of major depressive disorder. We also estimate a set of multivariate models to identify the effect of a variety of dimensions of major depression on the propensity to participate in the labor force, and be employed if participating. RESULTS: Lifetime and 12-month prevalence rates of depression are similar in and out of the labor force. Within the labor force, however, depression is strongly associated with unemployment. The negative relationship between depressive disorder and employment is particularly strong for middle age workers. Depression and the number of depressive episodes have a differing pattern of effects on labor market outcomes for men and women. We find evidence that labor force participation and employment rates for people with a history of depression increase significantly over time in the absence of additional depressive episodes. DISCUSSION: Labor market status represents an important dimension along which prevalence of major depression varies. The relationship between depression and employment status is particularly strong for middle aged persons, but becomes weaker as time passes since the last depressive episode. Continued exploration of the association between work (or lack of work) and depression may ultimately help in the prediction, treatment and assessment of the illness. IMPLICASIONS FOR PRACTICE AND POLICY: These results present a basic set of facts about the relationship between major depressive disorder and labor market outcomes. We have not, however, attempted to sort out the complexities of this relationship here. These complexities arise at almost every turn. For instance, the high level of prevalence of depression among the unemployed may be due to the possibility that the stresses associated with unemployment trigger depressive episodes or to the possibility that workers who are depressed are more likely to be fired or quit. IMPLICATIONS FOR FURTHER RESEARCH: Our continuing research attempts to address these problems. Understanding when and how depression affects labor market outcomes and when and how labor market outcomes affect depression is an important endeavor for those interested in treating the disease and understanding its consequences.

UNIVARIATE AND BIVARIATE LOGLINEAR MODELS FOR DISCRETE TEST SCORE DISTRIBUTIONS

ABSTRACTThe well‐developed theory of exponential families of distributions is applied to the problem of fitting the univariate histograms and discrete bivariate frequency distributions that often arise in the analysis of test scores. These models are powerful tools for many forms of parametric data smoothing and are particularly well‐suited to problems where there is little or no theory to guide a choice of probability models, e.g. smoothing a distribution to eliminate roughness and zero frequencies in order to equate scores from different tests. Attention is given to efficient computation of the maximum likelihood estimates of the parameters using Newton's Method and to computationally efficient methods for obtaining the asymptotic standard errors of the fitted frequencies and proportions. We discuss tools that can be used to diagnose the quality of the fitted frequencies for both the univariate and the bivariate cases. Five examples, using real data, are used to illustrate the methods of this paper.

A model for coding pollen size in reference to phylogeny using examples from the Ebenaceae

Most genetically based features should be available for use in cladistic analysis. Palynologists routinely measure polar (P) and equatorial (E) axes and place pollen into size classes defined by earlier pollen workers. Grouping of pollen into globally arbitrary classes may not correspond to statistically significant differences among the taxa of a study. We propose a model using conventional statistical procedures coupled with data visualization and Monte Carlo simulation. This approach is not a final solution to the general problem of coding continuous characters into discrete states; it is an attempt to address the problems of character state delimitation in pollen morphology. We suggest that the coding of continuous measurement variables (e.g., P, E) into character states should be done following a logical sequence of interactive visualization (2D and 3D) of bivariate frequency distributions including the inspection of prediction and confidence ellipses (e.g., 99%), and use of ANOVA. We illustrate our approach using realistic pollen data sets generated by a computer program (POLSIM) written to perform Monte Carlo sampling from normally distributed statistical populations of polar and equatorial axes. Our model is then applied to an original data set of 4,134 pollen grains from the Ebenaceae, resulting in the coding of the four genera into three character states for pollen size.