Decades Of Data Collection Research Articles

New model of long-term changes in spatiotemporal patterns of water quality across Shatt-Al-Arab River by applying GIS technique, from 1976 to 2020

PurposeUsing a combination of the geographical information system (GIS) and the Canadian water quality index (WQI), the current study sought to provide a long-term general assessment of the water quality of the Shatt Al-Arab River (SAAR), focusing on its suitability for living organisms. Likewise, SPSS statistics was used to develop a nonlinear WQI regression model for the study area.Design/methodology/approachThe study required four decades of data collection on some environmental characteristics of river water. After that, calculate the WQI and conduct the spatial analysis. Eight variables in total, including water temperature, dissolved oxygen, potential hydrogen ions, electrical conductivity (EC), biological oxygen demand, turbidity, nitrate and phosphate, were chosen to calculate the WQI.FindingsThroughout the study periods, the WQI values varied from 55.2 to 79.83, falling into the categories of four (marginal) and three (fair), with the sixth period (2007–2008) showing the most decline. The present research demonstrated that the high concentration of phosphates, the high EC values, and minor changes in the other environmental factors are the major causes of the decline in water quality. The variations in ecological variables' overlap are a senior contributor to changes in water quality in general. Notably, using GIS in conjunction with the WQI has shown to be very effective in reducing the time and effort spent on investigating water quality while obtaining precise findings and information at the lowest possible expense. Calibration and validation of the developed model showed that this model had a perfect estimate of the WQI value. Due to its flexibility and impartiality, this study recommends using the proposed model to estimate and predict the WQI in the study area.Originality/valueEven though the water quality of the SAAR has been the subject of numerous studies, this is the only long-term investigation that has been done to evaluate and predict its water quality.

Recent Quarkonia Measurements in Small Systems at RHIC and LHC Energies

Heavy-ion research at the Relativistic Heavy Ion Collider (RHIC) during the first decade of data collection, approximately during the years 2000–2010, was primarily focused on the study of Au+Au collisions. The search for evidence of quark-gluon plasma (QGP), a state of matter where quarks and gluons become unbound within a high energy density environment, which was at the forefront of research efforts. However, studies of the azimuthal anisotropy parameter v2 in p/d+Pb collisions from the Large Hadron Collider (LHC) yielded results consistent with the hydrodynamic flow, one of the signatures of quark-gluon plasma formation in heavy-ion collisions. Since the publication of these findings, the field of heavy-ion physics has made subsequent measurements in small system collisions to study cold nuclear matter effects as well as look for additional evidence of hot nuclear matter effects. Quarkonia, a bound state of a cc¯ or bb¯ pair, has often been used to probe a wide range of nuclear effects in both large and small collision systems. Here we will review recent quarkonia measurements in small system collisions at RHIC and LHC energies and summarize the experimental conclusions.

Carbon Sequestration and Subsidence Reversal in the Sacramento-San Joaquin Delta and Suisun Bay: Management Opportunities for Climate Mitigation and Adaptation

The aquatic landscapes of the Sacramento–San Joaquin Delta (hereafter, the Delta) and Suisun Bay represent both a significant past and future soil carbon stock. Historical alterations of hydrologic flows have led to depletion of soil carbon stocks via emissions of carbon dioxide (CO2), and loss of elevation as a result of subsidence. Optimizing ecosystem hydrology in the Delta and Suisun Bay could both reduce and reverse subsidence while also providing significant opportunities for climate mitigation and adaptation. Emissions of greenhouse gases (GHGs)—notably CO2, methane (CH4 ), and nitrous oxide (N2O)—contribute to global warming at different rates and intensities, requiring GHG accounting and modeling to assess the relative benefits of management options. Decades of data collection, model building, and map development suggest that past and current management actions have both caused—and can mitigate—losses of soil carbon. We review here the magnitude of potential GHG offsets, management options that may be achievable, and trade-offs of carbon storage under different land management. Using a land-use/land-cover framework to assess these management options, we describe the potential of three interventions (impoundment to reverse subsidence, agricultural management, and tidal reintroduction and/or maintained connectivity), both in acreage and radiative balance to clarify their relative influence on the region’s GHG balance today and in relation to its millennial history. From floodplains to farming to floating aquatic vegetation, we find specific scalable strategies to manage hydrology that can alter regional GHG balance. Preservation of soil carbon stocks and restoration of net atmospheric CO2 fluxes into soils are the primary route to net negative emissions in the Delta and Suisun Bay, with CH4 emission management occurring in a supporting role. Over a 40-year horizon of climate-mitigation markets, the resilience of different aquatic habitats introduces the most uncertainty, from expected and unexpected hydrologic changes associated with land, ocean, and operational water flows.

Neues aus dem RABBIT-Register

Seit 2001 rekrutieren Rheumatolog:innen deutschlandweit Patient:innen mit rheumatoider Arthritis in das Biologikaregister RABBIT, um die Langzeitsicherheit und -wirksamkeit moderner antirheumatischer Therapien zu untersuchen. In den vergangenen 20 Jahren wurden mehr als 20.000 Patient:innen in die prospektive Kohortenstudie eingeschlossen. In diesem Beitrag fassen wir aktuelle Forschungsergebnisse der Jahre 2020 und 2021 zusammen; dabei stehen Sicherheitsaspekte, Einflussfaktoren auf die Therapiewirksamkeit und patientenberichtete Outcomes im Fokus. Mit Herpes zoster, Fazialisparese und Psoriasis wurden verschiedene unerwünschte Ereignisse untersucht, die entweder als Sicherheitssignal aus klinischen Studien oder durch die EudraVigilance-Datenbank gemeldet wurden oder als paradoxe Reaktion unter medikamentöser Behandlung aufgetreten sind. Für diese Ereignisse wurde der Einfluss der biologischen DMARD(„disease-modifying antirheumatic drug“)-Therapie analysiert. In der Publikation zu Herpes zoster berücksichtigten wir auch die medikamentöse Behandlung mit Januskinaseinhibitoren. Starkes Übergewicht kann den Erfolg einer Therapie beeinflussen. Hier gibt es geschlechtsspezifische Unterschiede, und auch das Wirkprinzip einer Therapie entscheidet, ob eine Adipositas das Therapieansprechen reduziert. Die Mehrheit der in RABBIT beobachteten Patient:innen ist nach 1 Jahr Behandlung mit der erhaltenen Therapie zufrieden. Wir konnten zeigen, welche Faktoren die Zufriedenheit mit der Wirksamkeit und der Sicherheit der Behandlung begünstigen oder aber negativ beeinflussen. Diese Übersichtsarbeit zeigt, dass Langzeitbeobachtungsstudien wie das RABBIT-Register auch nach 2 Dekaden der Datenerhebung zum Verständnis von Therapierisiken beiträgt sowie Faktoren identifiziert, die die Wirkung der Therapien beeinflussen können.

Solar and Anthropogenic Influences on Climate: Regression Analysis and Tentative Predictions

The paper aims to quantify solar and anthropogenic influences on climate change, and to make some tentative predictions for the next hundred years. By means of double regression, we evaluate linear combinations of the logarithm of the carbon dioxide concentration and the geomagnetic aa index as a proxy for solar activity. Thereby, we reproduce the sea surface temperature (HadSST) since the middle of the 19th century with an adjusted R2 value of around 87 percent for a climate sensitivity (of TCR type) in the range of 0.6 K until 1.6 K per doubling of CO2. The solution of the double regression is quite sensitive: when including data from the last decade, the simultaneous occurrence of a strong El Niño and of low aa values leads to a preponderance of solutions with relatively high climate sensitivities around 1.6 K. If these later data are excluded, the regression delivers a significantly higher weight of the aa index and, correspondingly, a lower climate sensitivity going down to 0.6 K. The plausibility of such low values is discussed in view of recent experimental and satellite-borne measurements. We argue that a further decade of data collection will be needed to allow for a reliable distinction between low and high sensitivity values. In the second part, which builds on recent ideas about a quasi-deterministic planetary synchronization of the solar dynamo, we make a first attempt to predict the aa index and the resulting temperature anomaly for various typical CO2 scenarios. Even for the highest climate sensitivities, and an unabated linear CO2 increase, we predict only a mild additional temperature rise of around 1 K until the end of the century, while for the lower values an imminent temperature drop in the near future, followed by a rather flat temperature curve, is prognosticated.

Inter-annual variation in lake ice composition in the European Arctic: observations based on high-resolution thermistor strings

Abstract. Climate change and global warming strongly impact the cryosphere. The rise of air temperature and change of precipitation patterns lead to dramatic responses of snow and ice heat and mass balance. Sustainable field observations on lake air–snow–ice–water temperature regime have been carried out in Lake Orajärvi in the vicinity of the Finnish Space Centre, a Flagship Supersite in Sodankylä in Finnish Lapland since 2009. A thermistor-string-based snow and ice mass balance buoy called “Snow and ice mass balance apparatus (SIMBA)” was deployed in the lake at the beginning of each ice season. In this paper, we describe snow and ice temperature regimes, snow depth, ice thickness, and ice compositions retrieved from SIMBA observations as well as meteorological variables based on high-quality observations at the Finnish Space Centre. Ice thickness in Lake Orajärvi showed an increasing trend. During the decade of data collection (1) the November–May mean air temperature had an increasing trend of 0.16 ∘C per year, and the interannual variations were highly correlated (r = 0.93) with the total seasonal accumulated precipitation; (2) the maximum granular ice thickness ranged from 15 % to 80 % of the maximum total ice thickness; and (3) the snow depth on lake ice was not correlated (r = 0.21) with the total precipitation. The data set can be applied to investigate the lake ice surface heat balance and the role of snow in lake ice mass balance and to improve the parameterization of snow to ice transformation in snow and ice models. The data are archived at https://doi.org/10.5281/zenodo.4559368 (Cheng et al., 2021).

Reanalysis of Water Withdrawal for Irrigation, Electric Power, and Public Supply Sectors in the Conterminous United States, 1950–2016

AbstractAccurately measuring water use by the economy is essential for developing reliable models of water resource availability. Indeed, these models rely on retrospective analyses that provide insights into shifting human population demands and adaptions to water shortages. However, accurate, methodologically consistent, empirically authentic, and spatiotemporally comprehensive historical datasets for water withdrawals are scarce. Herein, we present a reanalysis of annual resolution (1950–2016) historical data set on irrigation, electric power, and public supply water withdrawal within the conterminous United States (US) at the county‐level, and, for power plants, at the site‐level. To estimate electric power water use, we synthesized a historically comprehensive list of generators and historic patterns in generation across fuels, prime movers, and cooling technologies. Irrigation water use estimation required building a crop‐demand model that utilized historical information on irrigated acreage for crops and golf courses, stage‐specific crop water demand, and climate information. To estimate public water supply use, we developed a random forest model constructed from information on population, infrastructure, climate, and land cover. These estimates generally agree with total county and state water use information provided by the US Geological Survey (USGS) water use circular and estimates generated from independent studies for specific years. However, we also observed discrepancies between our estimates and USGS data that appear to be caused by inconsistencies in the methods used by the USGS's primary data sources at the state level over decades of data collection, highlighting the importance of reanalysis to yield spatiotemporally consistent and intercomparable estimates of water use.

A Hybrid Learning Approach to Prognostics and Health Management Applied to Military Ground Vehicles Using Time-Series and Maintenance Event Data

Attempts to leverage operational time-series data in Condition Based Maintenance (CBM) approaches to optimize the life cycle management and Reliability, Availability, and Maintainability (RAM) of military vehicles have encountered several obstacles over decades of data collection. These obstacles have beset similar approaches on civilian ground vehicles, as well as on aircraft and other complex systems. Analysis of operational data is critical because it represents a continuous recording of the state of the system. Applying rudimentary data analytics to operational data can provide insights like fuel usage patterns or observed reliability of one vehicle or even a fleet. Monitoring trends and analyzing patterns in this data over time, however, can provide insight into the health of a vehicle, a complex system, or a fleet, predicting mean time to failure or compiling logistic or life cycle needs. Such High-Performance Data Analytics (HPDA) on operational time-series datasets has been historically difficult due to the large amount of data gathered from vehicle sensors, the lack of association between clusters observed in the data and failures or unscheduled maintenance events, and the deficiency of unsupervised learning techniques for time-series data. We present an HPDA environment and a method of discovering patterns in vehicle operational data that determines models for predicting the likelihood of imminent failure, referred to as Parameter-Based Indicators (PBIs). Our method is a data-driven approach that uses both time-series and relational maintenance data. This hybrid approach combines both supervised and unsupervised machine learning and data analytic techniques to correlate labeled, relational maintenance event data with unlabeled operational time-series data utilizing the DoD High Performance Computing (HPC) capabilities at the U.S. Army Engineer Research and Development Center. In leveraging both time-series and relational data, we demonstrate a means of fast, purely data-driven model creation that is more broadly applicable and requires less a priori information than physics informed, data-driven models. By blending these approaches, this system will be able to relate some lifecycle management goals through the workflow to generate specific PBIs that will predict failures or highlight appropriate areas of concern in individual or collective vehicle histories.

Invertebrates are declining in boreal aquatic habitat: The effect of brownification?

Surface water browning affects boreal lakes in the Northern Hemisphere. This process is expected to increase with global warming. Boreal lakes are the most numerous lakes on Earth. These ecosystems are particularly sensitive to disturbances due to their low biodiversity compared to other aquatic environments. The recent darkening of surface water is expected to hinder key ecosystem processes, particularly through lower primary productivity and loss of biodiversity. However, studies based on long-term data collections have rarely been conducted on the ecological consequences of water browning on aquatic food webs, especially concerning its impacts on invertebrate communities.For the first time, our analysis based on two decades of data collection in Finnish lakes highlighted a relation between water browning and a decline in aquatic macroinvertebrate abundances. Aquatic invertebrates are the main food resource for many secondary predators such as fish and waterbirds, hence such effect on their populations may have major consequences for boreal ecosystem functioning.

Theoretical Perspectives of the Baltimore Ecosystem Study: Conceptual Evolution in a Social-Ecological Research Project.

The Earth's population will become more than 80% urban during this century. This threshold is often regarded as sufficient justification for pursuing urban ecology. However, pursuit has primarily focused on building empirical richness, and urban ecology theory is rarely discussed. The Baltimore Ecosystem Study (BES) has been grounded in theory since its inception and its two decades of data collection have stimulated progress toward comprehensive urban theory. Emerging urban ecology theory integrates biology, physical sciences, social sciences, and urban design, probes interdisciplinary frontiers while being founded on textbook disciplinary theories, and accommodates surprising empirical results. Theoretical growth in urban ecology has relied on refined frameworks, increased disciplinary scope, and longevity of interdisciplinary interactions. We describe the theories used by BES initially, and trace ongoing theoretical development that increasingly reflects the hybrid biological–physical–social nature of the Baltimore ecosystem. The specific mix of theories used in Baltimore likely will require modification when applied to other urban areas, but the developmental process, and the key results, will continue to benefit other urban social–ecological research projects.

African footballers’ life cycles according to the analysis of transfer value along their career path: a case study of Ghanaian players

The evolution of the international transfer market continues to demonstrate the vibrancy and attractiveness of the UEFA clubs and leagues. This explains why African players are attracted to a professional career in European clubs. Based on two decades of data collection (1994–2014), this article analyses the evolution of African players’ careers with the case of Ghanaian home-grown players’ mobility in the international transfer market. The players’ career dynamic is based on a combination of transfer values and their ages. We relied on data from transfer records, information on the football labour market and the product life cycle theory to identify African players’ career dynamics. This allows us to determine the four cycles in players’ careers: domestic development, international career development, maturity and the decline which corresponds to the nonlinear evolution of their transfer values. The results supported to construct the African footballers’ ‘Careers’ Path Model Dynamics (CPMD)’ of professional players.

Geoarchaeological and 3D visualisation approaches for contextualising in-situ fossil bearing palaeokarst in South Africa: A case study from the ∼2.61 Ma Drimolen Makondo

South Africa contains a wealth of palaeokarst deposits that have yielded hominin fossils and Early Stone Age archaeology. Despite the complex nature of deposition within many of these caves there has been a dearth of detailed geoarchaeological studies undertaken on these sites. Many sites in South Africa have been interpreted using an overly simplistic Member System based on simplified sedimentological attributes, rather than chronostratigrahic units. Many of the defined Members thus identify different, but contemporary geological processes occurring in the caves. This has caused serious confusion in reconstructing the life histories of palaeocaves and the ages of the fossil remains interned within them. It is critical to uncover new sites that have not been extensively altered by decades of data collection and destructive mining techniques employed early in their discovery. Although unmined sites present their own problems with regards to extensive colluvium cover and access to fossil-bearing units, analysing strata that is found in-situ enhances overall confidence of interpretations drawn. A wealth of geoarchaeological and 3D visualisation techniques can now be employed to aid in the understanding of cave life histories, as well as their excavation. In this paper we present the first attempt to integrate and publish data from a range of such methods on South African fossil bearing palaeokarst using the newly discovered Drimolen Makondo deposit as a case study. This includes the use of ground penetrating radar, 3D visualisation through photogrammetry and multi-scale 3D scanning, micromophology and petrography, palaeomagnetism, mineral magnetism, synchrotron radiation, electron spin resonance, uranium-lead dating and biochronology. Our analysis has allowed us to successfully uncover the full extent of this new ∼2.61 Ma fossil bearing palaeokarst deposit and to visualise and interpret its chronostratigraphy.

Key Performance Indicators in the Evaluation of the Quality of Radiation Safety Programs.

Beaumont is a multiple hospital health care system with a centralized radiation safety department. The health system operates under a broad scope Nuclear Regulatory Commission license but also maintains several other limited use NRC licenses in off-site facilities and clinics. The hospital-based program is expansive including diagnostic radiology and nuclear medicine (molecular imaging), interventional radiology, a comprehensive cardiovascular program, multiple forms of radiation therapy (low dose rate brachytherapy, high dose rate brachytherapy, external beam radiotherapy, and gamma knife), and the Research Institute (including basic bench top, human and animal). Each year, in the annual report, data is analyzed and then tracked and trended. While any summary report will, by nature, include items such as the number of pieces of equipment, inspections performed, staff monitored and educated and other similar parameters, not all include an objective review of the quality and effectiveness of the program. Through objective numerical data Beaumont adopted seven key performance indicators. The assertion made is that key performance indicators can be used to establish benchmarks for evaluation and comparison of the effectiveness and quality of radiation safety programs. Based on over a decade of data collection, and adoption of key performance indicators, this paper demonstrates one way to establish objective benchmarking for radiation safety programs in the health care environment.

Empirical Integrity Verification of GNSS and SBAS Based on the Extreme Value Theory

Performance verification of GNSS-based safety-of-life systems requires demonstration that the probability of an excessive positioning error is as small as 10 − 7 or even smaller. Integrity concepts are based on the requisite that the system provides conservative performance estimates for alert generation. The GNSS Integrity Monitoring and Analysis Tool (GIMAT) developed by the authors focuses on data-based analyses to verify whether this is indeed the case. Since the tails of the error distributions must be investigated, it is impractical to simply use observed cases of performance over-estimation. Such events are – by design – extremely rare and would require many decades of data collection. Nevertheless, system verification requires assessment of a system's integrity performance within limited time. GIMAT therefore exploits Extreme Value Theory (EVT), which enables extrapolation of the observed distribution's tail into the misleading information domain. The paper presents a short introduction into the mathematical theory of EVT in the context of integrity verification, and contains real-life results that are obtained from the analysis of EGNOS data. Based on two months of data, it is shown that EGNOS is compliant with ICAO requirements for this period, and that EVT is successful in predicting integrity performance of navigation systems at high confidence levels. Copyright © 2014 Institute of Navigation.

Using existing cohorts in research on environmental causes of diseases – pros and cons from a European Perspective

Cohorts are an excellent method to study the role of environmental factors in causing chronic diseases, but usually takes decades of data collection. Further studying environmental causes of diseases requires assessment of environmental exposures. However many environmental exposures can be assessed independently from study subjects by retrospective characterization using existing monitoring data and modeling. Therefore it is tempting to add retrospective and prospective environmental exposure assessment to existing cohorts for studying the role of such factors in causation of chronic diseases. An example of such studies is the ESCAPE (European Study of Cohorts for Air Pollution Effects) which is a large inter-disciplinary collaboration of 25 European partners in 17 countries linking 32 existing cohort studies including the SAPALDIA cohort in Switzerland. It aims to characterize long term exposure to traffic related pollution and its association with chronic pathologies with particular reference to pregnancy & birth outcomes, respiratory diseases, cardiovascular diseases and cancer. The work package for respiratory health in adults aims to investigate the effect of ambient air pollution on the level and change of lung function (FVC and FEV1), prevalence and incidence of COPD, prevalence of chronic bronchitis symptoms and incidence of asthma. Such studies using existing cohorts are faster, cheaper and efficient due to availability of long term health information including early life time covariates, socio-economic information, past changes in health and known co-factors. Availability of different phenotypes and biobanks are also advantageous. If environmental monitoring data are available it is easy to link with existing cohort data. However the major disadvantage will be the heterogeneity of study designs with respect to population selection, sampling, age structure etc. Large heterogeneity can occur with the questionnaires used, the health assessment methods, phenotype definitions, biobank markers, and quality of retrospective exposure assessment. Therefore “other-purpose” existing cohorts are complementary but not an alternative to establishing fully standardized cohorts, biobanks and enviro-banks. Large scale new mega cohorts with biobanks and enviro-banks have major scientific advantages that cannot be accomplished with uncoordinated smaller cohorts.

Racial/ethnic differences in the criterion-related validity of cognitive ability tests: A qualitative and quantitative review.

The correlation between cognitive ability test scores and performance was separately meta-analyzed for Asian, Black, Hispanic, and White racial/ethnic subgroups. Compared to the average White observed correlation ( = .33, N = 903,779), average correlations were lower for Black samples ( = .24, N = 112,194) and Hispanic samples ( = .30, N = 51,205) and approximately equal for Asian samples ( = .33, N = 80,705). Despite some moderating effects (e.g., type of performance criterion, decade of data collection, job complexity), validity favored White over Black and Hispanic test takers in almost all conditions that included a sizable number of studies. Black-White validity comparisons were possible both across and within the 3 broad domains that use cognitive ability tests for high-stakes selection and placement: civilian employment, educational admissions, and the military. The trend of lower Black validity was repeated in each domain; however, average Black-White validity differences were largest in military studies and smallest in educational and employment studies. Further investigation of the reasons for these validity differences is warranted.

Predicting Teacher Performance With Test Scores and Grade Point Average: A Meta-Analysis

A meta-analysis was conducted to examine the degree to which teachers’ test scores and their performance in preparation programs as measured by their collegiate grade point average (GPA) predicted their teaching competence. Results from 123 studies that yielded 715 effect sizes were analyzed, and the mediating effects of test and GPA type, criterion type, teaching level, service level, and decade of data collection were considered. It was found that test scores were at best modestly related to teaching competence and that performance in preparation programs was a significantly better predictor of teaching skill. Results revealed that test scores likely do not provide additional information beyond preservice performance to safeguard the public from incompetent teaching.

Biodiversity and ecosystem stability in a decade-long grassland experiment

Human-driven ecosystem simplification has highlighted questions about how the number of species in an ecosystem influences its functioning. Although biodiversity is now known to affect ecosystem productivity, its effects on stability are debated. Here we present a long-term experimental field test of the diversity-stability hypothesis. During a decade of data collection in an experiment that directly controlled the number of perennial prairie species, growing-season climate varied considerably, causing year-to-year variation in abundances of plant species and in ecosystem productivity. We found that greater numbers of plant species led to greater temporal stability of ecosystem annual aboveground plant production. In particular, the decadal temporal stability of the ecosystem, whether measured with intervals of two, five or ten years, was significantly greater at higher plant diversity and tended to increase as plots matured. Ecosystem stability was also positively dependent on root mass, which is a measure of perenniating biomass. Temporal stability of the ecosystem increased with diversity, despite a lower temporal stability of individual species, because of both portfolio (statistical averaging) and overyielding effects. However, we found no evidence of a covariance effect. Our results indicate that the reliable, efficient and sustainable supply of some foods (for example, livestock fodder), biofuels and ecosystem services can be enhanced by the use of biodiversity.

The Use of PNAD in Migratory Analysis: Possibilities, Lacks and Methodological Challenges

In the nineties, after more than a decade of data collection, PNAD's basic questionnaire included systematic data collection on migration. Nevertheless, scholars and specially demographers have seldom explored this data source. This paper is part of a major evaluation project of PNAD in the nineties. It presents the potentials of this data source for migration research and discusses ways to improve data collection. To assess the quality of PNAD's migration estimates, data on volumes and flows were comparable to the ones obtained from the 1991 Demographic Census and the 1996 In the nineties, after more than a decade of data collection, PNAD's basic questionnaire included systematic data collection on migration. Nevertheless, scholars and specially demographers have seldom explored this data source. This paper is part of a major evaluation project of PNAD in the nineties. It presents the potentials of this data source for migration research and discusses ways to improve data collection. To assess the quality of PNAD's migration estimates, data on volumes and flows were comparable to the ones obtained from the 1991 Demographic Census and the 1996 General Census Count. The results demonstrate that PNAD is a reliable and rich data source to study migration and should be more widely used. This effort would enable scholars to develop novel and creative means of data analysis techniques and improve current instruments for data collection on migration.

Fate and Fortune in Rural China: Social Organization and Population Behavior in Liaoning, 1774-1873 (review)

Reviewed by: Fate and Fortune in Rural China: Social Organization and Population Behavior in Liaoning 1774–1873 Norma Diamond (bio) James Z. Lee and Cameron D. Campbell, with contributions by Chris J. Myers and Yizhuang Ding. Fate and Fortune in Rural China: Social Organization and Population Behavior in Liaoning 1774–1873. Cambridge, New York, and Melbourne: Cambridge University Press, 1997. xxi, 280 pp. Hardcover $49.95, ISBN 0–521–58119–2. This monograph is the culmination of almost two decades of data collection from and analysis of the household registers of a village called Daoyi and its neighboring hamlets. Located near Shenyang, these communities were a part of the Eight Banner Han Chinese Army. They were situated on state-owned lands that were allocated to the member households. Able-bodied men were liable for military service or corvée labor. Depending on their ability, some men in this Han Chinese martial population held offices and rank within the Banner system. Current residents who trace their ancestry to this earlier population hold that the original settlers came from Shandong. In many ways, this was very much a Chinese village, though not a "typical" one. Nor was it unique: the authors point out that during the Qing, 10 percent of all farmland was state-owned and managed by the Banners or tuntian garrisons, with a similar social organization. The household registers, compiled every three years, cover the period 1774- 1873. Over this century the population grew from 2,192 to 3,271 with only a small percentage of growth attributable to new immigration. At the same time, the number of registered households fell from 530 to 412 as a result of a trend toward complex household forms. The registers provide a careful accounting of births, marriages, deaths, occupations, and offices, and indicate the gender of each household member and his/ her relationship to the recognized head of the unit. Lee and his coauthors have done a remarkable and painstaking job of organizing the raw data into a variety of tables that show the shifts and continuities over time in birth and death rates, fertility rates and birth intervals, life expectancies, and nuptiality. Further tables demonstrate the relation between the demographic variables and such features as household structure, position within the family hierarchy, and social mobility. Household registers have an advantage over genealogies for writing a broad demographic history such as this: genealogies pay little attention to women and tend to omit kinsmen who were economic failures and/or left no surviving heirs. But even the Banner registers have omissions. They do not list servants and hired hands, and sometimes fail to explain the disappearance of family members from one compilation to the next. This study lays the groundwork for answering other questions that might be dealt with in the future by recourse to other materials in the archives. What seems [End Page 117] to be lacking here is a detailed economic context. The reader is told little about family landholdings or how lands were assigned or redistributed after the death of the original assignee. We are told that land could not be bought or sold, and a footnote on page 7 says that "in theory, the state initially provided each adult bannerman with the equivalent of 36 mu." Did this policy continue over the century, and how does it relate to household formation or division? It would also be useful to have information about the size of stipends paid to those at various ranks in the military, in artisan and specialized worker positions, or Banner official posts, along with estimates of income from corvée labor. This would shed light on income differences between households or between household segments in the more complex structures, and additionally provide clues to decisions about household division. Along the same line of inquiry, I wonder if there is a relation between the work-related absences from home of males (as soldiers, military support artisans, and transport workers) and the maintenance of joint households with home-bound brothers or other close kin in order to assure the security and support of spouses and children. Similar practical reasoning may be involved when the man falls into the category...