Additional Years Of Data Research Articles

Evaluating the Consequences of Adjusting Fish Stock Assessment Estimates of Biomass for Retrospective Patterns using Mohn's Rho

AbstractA retrospective pattern exists when estimates of some assessment parameter for a given time period (e.g., biomass in a given year) trend in a systematic way as additional periods of data (i.e., typically a year) are added. Causes of such patterns are difficult to determine, and the pattern does not necessarily indicate the direction of the parameter bias. Mohn's rho measures the severity of retrospective patterns and has been used to adjust estimates of biomass and quotas. The consequences of applying Mohn's rho rather than ignoring the pattern are unclear. I used an age‐structured simulation based on Atlantic Herring Clupea harengus to evaluate the consequences of ignoring retrospective patterns versus applying Mohn's rho. When the application of Mohn's rho produced more accurate estimates of biomass, subsequent spawning stock biomass and yields were near target levels. When the use of Mohn's rho produced less‐accurate estimates of biomass, the results depended on the direction of the pattern. With a positive retrospective pattern (i.e., estimates of biomass for a given year decline as additional years of data are added), the application of Mohn's rho lowered the estimates of biomass, producing little cost in long‐term yield relative to the subsequent increases in biomass but resulting in a short‐term cost of lower annual quotas. With a negative retrospective pattern (i.e., estimates of biomass for a given year increase as additional years of data are included), the use of Mohn's rho increased the estimates of biomass, thus generating long‐term costs in yield and biomass but with a short‐term benefit of higher annual quotas. The decision of whether to ignore retrospective patterns or apply Mohn's rho should depend on the direction of the pattern and the relative weight of short‐ and long‐term fishery objectives. Performance may also depend on the shape of the control rules that are used to define annual quotas.Received May 14, 2013; accepted January 2, 2014

Neisseria meningitidisSerogroup W, Burkina Faso, 2012

In 2010, Burkina Faso became the first country to introduce meningococcal serogroup A conjugate vaccine (PsA-TT). During 2012, Burkina Faso reported increases in Neisseria meningitidis serogroup W, raising questions about whether these cases were a natural increase in disease or resulted from serogroup replacement after PsA-TT introduction. We analyzed national surveillance data to describe the epidemiology of serogroup W and genotyped 61 serogroup W isolates. In 2012, a total of 5,807 meningitis cases were reported through enhanced surveillance, of which 2,353 (41%) were laboratory confirmed. The predominant organism identified was N. meningitidis serogroup W (62%), and all serogroup W isolates characterized belonged to clonal complex 11. Although additional years of data are needed before we can understand the epidemiology of serogroup W after PsA–TT introduction, these data suggest that serogroup W will remain a major cause of sporadic disease and has epidemic potential, underscoring the need to maintain high-quality case-based meningitis surveillance after PsA–TT introduction.

Apparent survival rates of forest birds in eastern Ecuador revisited: improvement in precision but no change in estimates.

Knowledge of survival rates of Neotropical landbirds remains limited, with estimates of apparent survival available from relatively few sites and species. Previously, capture-mark-recapture models were used to estimate apparent survival of 31 species (30 passerines, 1 Trochilidae) from eastern Ecuador based on data collected from 2001 to 2006. Here, estimates are updated with data from 2001-2012 to determine how additional years of data affect estimates; estimates for six additional species are provided. Models assuming constant survival had highest support for 19 of 31 species when based on 12 years of data compared to 27 when based on six; models incorporating effects of transients had the highest support for 12 of 31 species compared to four when based on 12 and six years, respectively. Average apparent survival based on the most highly-supported model (based on model averaging, when appropriate) was 0.59 (± 0.02 SE) across 30 species of passerines when based on 12 years and 0.57 (± 0.02) when based on six. Standard errors of survival estimates based on 12 years were approximately half those based on six years. Of 31 species in both data sets, estimates of apparent survival were somewhat lower for 13, somewhat higher for 17, and remained unchanged for one; confidence intervals for estimates based on six and 12 years of data overlapped for all species. Results indicate that estimates of apparent survival are comparable but more precise when based on longer-term data sets; standard error of the estimates was negatively correlated with numbers of captures (rs = −0.72) and recaptures (rs = −0.93, P<0.001 in both cases). Thus, reasonable estimates of apparent survival may be obtained with relatively few years of data if sample sizes are sufficient.

Factors Associated with Participation in and Benefits of a Worksite Wellness Program

The objective of this study was to describe employees most likely to participate in a Personal Wellness Profile (PWP) and/or in a worksite Wellness Program (WP), and to identify whether an association exists between participation and trends in number of health care services and cost of services per person. A retrospective cohort study was conducted using medical claims data from the Deseret Mutual Benefit Administrators, 2004 through 2009. The PWP and WP involved more than 30% of employee contract holders. Participation in the PWP and WP were lower in the older age group and higher among women, married people, and those with an annual income of at least $40,000. Average annual cost per person during 2004-2006 was significantly positively associated with completing the PWP in 2007-2009. Those in the highest quartile for average annual cost per person in 2004-2006 were significantly less likely to participate in the WP in 2007-2009. During 2004-2009, a significantly increasing trend in average annual cost per person was similar, but at a lower level for PWP participants. The trend line also was lower for WP participants, and increased at a lower rate. The lower rate of increase in the trends for average cost per person among those in the WP indicates that the intervention is effective at slowing escalating costs. Additional years of data should be assessed, when available, to confirm this pattern.

AHA 2012: Prevention a key focus of meeting

The American Heart Association (AHA) Scientific Sessions 2012 brought together leading experts from around the world to discuss successes and new initiatives aimed at reducing the burden of cardiovascular disease (CVD). A key focus of the meeting was on treatments aimed at preventing cardiovascular events. In addition, the meeting discussed the efficacy of novel therapies and safety of marketed treatments. A review of select late-breaking trials and other presentations will be covered in this article.

Extension of the Representativeness of the Traumatic Brain Injury Model Systems National Database

To extend the representativeness of the Traumatic Brain Injury Model Systems National Database (TBIMS-NDB) for individuals 16 years and older, admitted for acute, inpatient rehabilitation in the United States with a primary diagnosis of traumatic brain injury (TBI) analyses completed by Corrigan and colleagues by comparing this data set to national data for patients admitted to inpatient rehabilitation with identical inclusion criteria that included 3 additional years of data and 2 new demographic variables. Secondary analysis of existing data sets and extension of previously published analyses. Acute inpatient rehabilitation facilities. Patients 16 years and older with a primary rehabilitation diagnosis of TBI; the US TBI Rehabilitation population, n = 156 447; and the TBIMS-NDB population, n = 7373. None. Demographics, functional status, and length of stay in hospital. The TBIMS-NDB was largely representative of patients 16 years and older, admitted for rehabilitation in the United States with a primary diagnosis of TBI on or after October 1, 2001, and discharged as of December 31, 2010. The results of the extended analyses were similar to those reported by Corrigan and colleagues. Age accounted for the largest difference between the samples, with the TBIMS-NDB including a smaller proportion of patients 65 years and older than all those admitted for rehabilitation with a primary diagnosis of TBI in the United States. After partitioning each data set at age 65, most distributional differences found between samples were markedly reduced; however, differences in the preinjury vocational status of the employed and rehabilitation lengths of stay between 1 and 9 days remained robust. The subsamples of patients 64 years and younger were found to differ only slightly on all remaining variables, whereas those 65 years and older were found to have meaningful differences in insurance type and age distribution. These results reconfirm that the TBIMS-NDB is largely representative of patients with TBI receiving inpatient rehabilitation in the United States. Differences between the 2 data sets were found to be stable across the 3 additional years of data, and new differences were limited to those involving newly introduced variables. To use these data for population-based research, it is strongly recommended that statistical adjustment be conducted to account for the lower percentage of patients older than 65 years, inpatient rehabilitation stays less than 10 days, and preinjury vocational status in the TBIMS-NDB.

Revisiting WalMart’s Impact on Iowa Small-Town Retail

Ken Stone conducted the first study of WalMart stores’ economic impact in Iowa in 1988. Since then, research on WalMart’s impacts has exploded. Recent studies employ sophisticated statistical techniques to more accurately measure the size and direction of effects. Many reach conclusions similar to Stone’s original work. This article updates the original Stone study with additional years of data. It draws on recent methodological advances to help account for the effects of WalMart’s strategic location decisions on estimated retail sales in Iowa. As is consistent with previous studies, we find that WalMart’s entry into smaller trade centers in Iowa had a big initial impact on host-town retail sales, with some categories experiencing significant increases while others saw declines in sales per capita. WalMart’s presence helped stabilize or even expand the local retail sector of most rural Iowa host communities. To conclude, we discuss policy implications for local economic development officials.

Methods for design flood estimation in South Africa

The estimation of design floods is necessary for the design of hydraulic structures and to quantify the risk of failure of the structures. Most of the methods used for design flood estimation in South Africa were developed in the late 1960s and early 1970s and are in need of updating with more than 40 years of additional data currently available and with new approaches used internationally. This paper reviews methods used for design flood estimation in South Africa and internationally and highlights research needs in order to update the methods used for design flood estimation in South Africa.

A tentative gamma-ray line from Dark Matter annihilation at the Fermi Large Area Telescope

The observation of a gamma-ray line in the cosmic-ray fluxes wouldbe a smoking-gun signature for dark matter annihilation or decay in theUniverse. We present an improved search for such signatures in the data ofthe Fermi Large Area Telescope (LAT), concentrating on energies between 20and 300 GeV. Besides updating to 43 months of data, we use a new data-driventechnique to select optimized target regions depending on the profile of theGalactic dark matter halo. In regions close to the Galactic center, we find a4.6σ indication for a gamma-ray line at Eγ ≈ 130 GeV. Whentaking into account the look-elsewhere effect the significance of the observedexcess is 3.2σ. If interpreted in terms of dark matter particlesannihilating into a photon pair, the observations imply a dark matter mass ofmχ = 129.8±2.4 +7−13 GeV and a partial annihilationcross-section of ⟨σv⟩χχ → γγ = (1.27±0.32 +0.18−0.28) × 10−27cm3s−1 whenusing the Einasto dark matter profile. The evidence for the signal is based onabout 50 photons; it will take a few years of additional data to clarify itsexistence.

Regional Flood-Frequency Analysis: How We Got Here and Where We Are Going

= maximum discharge; A = drainage area; andC = coefficient related to the region. O’Connell chose a valueof 0.5 for the exponent, assuming in the absence of sufficient datathat the relationship between discharge and area was parabolic(Dooge 1986).With nearly 50 years of additional data, Fuller (1914) analyzedlong records of daily flows and peak flows from around the world,but particularly from the United States. He related the average ofthe maximum floods (Q¯ ) to the drainage area with an exponentof 0.8Q¯ ¼ CA

Predicting long-term graft survival in adult kidney transplant recipients

The ability to accurately predict a population's long-term survival has important implications for quantifying the benefits of transplantation. To identify a model that can accurately predict a kidney transplant population's long-term graft survival, we retrospectively studied the United Network of Organ Sharing data from 13,111 kidney-only transplants completed in 1988- 1989. Nineteen-year death-censored graft survival (DCGS) projections were calculated and compared with the population's actual graft survival. The projection curves were created using a two-part estimation model that (1) fits a Kaplan-Meier survival curve immediately after transplant (Part A) and (2) uses truncated observational data to model a survival function for long-term projection (Part B). Projection curves were examined using varying amounts of time to fit both parts of the model. The accuracy of the projection curve was determined by examining whether predicted survival fell within the 95% confidence interval for the 19-year Kaplan-Meier survival, and the sample size needed to detect the difference in projected versus observed survival in a clinical trial. The 19-year DCGS was 40.7% (39.8-41.6%). Excellent predictability (41.3%) can be achieved when Part A is fit for three years and Part B is projected using two additional years of data. Using less than five total years of data tended to overestimate the population's long-term survival, accurate prediction of long-term DCGS is possible, but requires attention to the quantity data used in the projection method.

DRAINMOD: Model Use, Calibration, and Validation

DRAINMOD is a process-based, distributed, field-scale model developed to describe the hydrology of poorly drained and artificially drained soils. The model is based on water balances in the soil profile, on the field surface, and, in some cases, in the drainage system. This article briefly describes the model and the algorithms that are used to quantify the various hydrologic components. Inputs for soil properties, site parameters, weather data, and crop characteristics required in the application of the model are presented and discussed with respect to their role in calibration. Methods for determining field effective values of key inputs to the model, either independently or as a part of the calibration process, are demonstrated in a case study. The case study involved calibrating DRAINMOD with two years of field data for a subsurface drained agricultural field in eastern North Carolina, followed by testing or validation of the model with two additional years of data. Performance statistics indicated that the model with calibrated input data accurately predicted daily water table depths with Nash-Sutcliffe modeling efficiency (EF) values of 0.68 and 0.72, daily drainage rates (EF = 0.73 and 0.49), and monthly drainage volumes (EF = 0.87 and 0.77) for the two-year validation period.

Labour Productivity Measures from the ABS: 1998 to 2009

This article compares micro and macro measures of productivity. Detailed industry-level productivity estimates are key to understanding how the aggregate economy is driven by the performance of particular sectors, and also how certain sectors perform relative to others. A detailed focus is all the more important in the aftermath of the UK's deepest recession since the 1930s. This article aims to aid the analysis of the economy over the recession and comment on which specific industries saw the biggest changes. The article updates the work of Long (2010) by adding two additional years of data from the Annual Business Survey (ABS), 2008 and 2009.

ESTIMATING RICARDIAN MODELS WITH PANEL DATA

Although the Ricardian model is a cross sectional method, there are advantages to estimating the model with additional years of data. For instance, with a panel, one can more easily separate events in a single year (e.g. weather and price shocks) from longer term phenomenon such as climate. Many early studies used repeated cross sections to study panel data but one can get consistently better performance from panel methods. In this paper, we rely on two panel methods to estimate the Ricardian function for the United States across time. The results suggest that moderate warming scenarios would benefit American agriculture as a whole but more extreme climate scenarios would be damaging.

The Impact of Frequency and Duration of Air Quality Monitoring: Atlanta, GA, Data Modeling of Air Pollution and Mortality

ABSTRACT The purpose of this analysis is threefold. We first examine the extent to which a longer series of data improves our understanding of air pollution on human mortality in the Atlanta, GA, area by updating the findings presented in Klemm and Mason (J. Air Waste Manage. Assoc. 2000, 50, 1433-1439) and Klemm et al. (Inhal. Toxicol. 2004, 16 (Suppl 1), 131-141) with 7.5 additional years of data. We explore estimated effects on two age groups (<65 and 65+) and four categories of cause of death. Second, we investigate how enlarging the geographic area of inquiry influences the estimated effects. Third, because some air quality (AQ) measures are monitored less frequently than daily, we investigate the extent to which AQ measurement frequency can influence estimates of relationships with human mortality. Our analytical approach employs a Poisson regression model using generalized linear modeling in S-Plus to estimate the relationship between daily AQ measures and daily mortality counts. We show that the estimated effects and their associated t values vary by year for nine AQ measures (particulate matter with aerodynamic diameter ≤2.5 μm [PM2.5], elemental carbon [EC], organic carbon [OC], NO3, SO4, O3, NO2, CO, and SO2). Several of the estimated AQ effects show downward trends during the 9-year period of study. The estimated effects tend to be strongest for the AQ measurement during the day of death and tend to decrease with additional lags. Enlarging the geographic area from two to four counties in the metropolitan area decreased the estimated effects, perhaps partly due to the fact that the measurement site is located in one of the two original counties. Estimated effects utilizing data as if the AQ were only measured every 3rd or every 6th day each week or twice per week vary from lower to higher than that estimated with daily measurements, although the t values are lower, as expected. IMPLICATIONS The ranges of published estimated effects of air quality measures on mortality suggest both underlying complexities and statistical variability. Decision-makers may be uncertain as to how to best use subgroup estimates; however, they should be aware of random fluctuations and underlying trends. Results from three scenarios of reduced frequencies of air quality measure monitoring show that estimated effects may differ substantially from those estimated from daily measurements. Although individual annual estimates will fluctuate, analysis of their trends provides information not available from analyzing the entire period as a whole. Daily measurements are essential for precise estimates of health effects.

Strike Force Piccadilly and ATM Security: A Follow-up Study

This article provides a follow-up evaluation of 'Strike Force Piccadilly'-a successful New South Wales Police public-private partnership to combat Automatic Teller Machine (ATM) ram raids [Prenzler, T. (2009). 'Strike Force Piccadilly: A Public-Private Partnership to Stop ATM Ram Raids.' Policing: An International Journal of Police Strategies and Management 32: 209-225]. The original study showed a significant reduction in raids 12 months after the implementation of a range of countermeasures including a 1800 police hotline, relocation of ATMs, and the installation of anti-ramming devices. The present study adds 2 years of additional data from 2008 to 2010. It was found that the reduction in ram raids was sustained and reduced even further. At the same time, there was a shift in offender tactics to the use of explosive 'gas attacks' in 2008. This problem was in turn minimized by police investigations, the incapacitation of gang members, and the installation of gas detection and disabling equipment. The follow-up study reinforced the value of public-private crime reduction partnerships and the need to be adaptive to new threats.

Long-term water balance and conceptual model of a semi-arid mountainous catchment

summary Long-term water balance investigations are needed to better understand hydrologic systems, especially semi-arid mountainous catchments. These systems exhibit considerable interannual variability in precipitation as well as spatial variation in snow accumulation, soils, and vegetation. This study extended a previous 10-year water balance based on measurements and model simulations to 24 years for the Upper Sheep Creek (USC) catchment, a 26 ha, snow-fed, semi-arid rangeland headwater drainage within the Reynolds Creek Experimental Watershed in southwestern Idaho, USA. Additional analyses afforded by the additional years of data demonstrated that the variability between streamflow and annual precipitation (r 2 = 0.54) could be explained by the timing of precipitation and antecedent moisture conditions. Winter–spring precipitation and soil moisture deficit at the beginning of the water year accounted for 83% of the variability in streamflow, which was almost as accurate as applying the more complex physically-based Simultaneous Heat and Water (SHAW) numerical model (r 2 = 0.85) over the three dominant land cover classes. A conceptual model was formulated based on field observations, numerical simulations and previous studies. Winter precipitation and spring snowmelt must first replenish the deficit within the soil water profile and ground water system before water is delivered to the stream. During this period, surface water and ground water are tightly coupled and their interaction is critical to streamflow generation. Shortly after snow ablation, however, water flux in the root zone becomes decoupled from the ground water system and subsequent precipitation does little to contribute to streamflow for the current year, but serves to offset ET and the soil moisture deficit at the beginning of the following year. This study demonstrates the merits of long-term catchment-scale research to improve our understanding of how climate and land cover interact to control hydrologic dynamics in complex mountainous terrain. Published by Elsevier B.V.

Newly Recovered Microdata on U.S. Manufacturing Plants from the 1950s and 1960s: Some Early Glimpses

Longitudinally-linked microdata on U.S. manufacturing plants are currently available to researchers for 1963, 1967, and 1972-2009. In this paper, we provide a first look at recently recovered manufacturing microdata files from the 1950s and 1960s. We describe their origins and background, discuss their contents, and begin to explore their sample coverage. We also begin to examine whether the available establishment identifier(s) allow record linking. Our preliminary analyses suggest that longitudinally-linked Annual Survey of Manufactures microdata from the mid-1950s through the present – containing 16 years of additional data – appears possible though challenging. While a great deal of work remains, we see tremendous value in extending the manufacturing microdata series back into time. With these data, new lines of research become possible and many others can be revisited.

Relationship between Gulf Menhaden Recruitment and Mississippi River Flow: Model Development and Potential Application for Management

AbstractThe Gulf menhaden Brevoortia patronus is one of the most abundant pelagic fishes in the northern coastal Gulf of Mexico (hereafter, “Gulf”) and is the principal forage for various commercial and sport fishes, sea birds, and marine mammals. Part of the life history of Gulf menhaden is spent on the continental shelf and part is spent within estuaries. Adults spawn near the mouth of the Mississippi River, and larvae aggregate within the river plume front. Larval Gulf menhaden transit the continental shelf and enter estuaries of the northern Gulf as juveniles. Govoni (1997) demonstrated an association between the discharge of the Mississippi and Atchafalaya rivers and Gulf menhaden recruitment. In particular, he found an inverse association between Mississippi River discharge and estimated recruitment of half‐year‐old fish based on recruitment data from Vaughan et al. (1996). Vaughan et al. (2000) updated this relationship with a regression analysis. Here, we revisit the relationship with additional years of data through 2004. The inverse relationship continues to hold. In addition, we reframed this relationship to produce a 1‐year‐ahead prediction model for forecasting recruitment to age 1 from Mississippi River discharge; this model can be used in proactive fishery management. Finally, we revisited the stock assessment model of Vaughan et al. (2007) and demonstrated an improvement in model performance when information on annual river discharge was incorporated.Received August 4, 2010; accepted March 10, 2011

Can Additional Resources Lead to Higher Levels of Productivity (Arrests) in Police Agencies?

While most police chiefs might be willing to make such a claim that there is a positive relationship between COPS grants and police arrests, empirical research on this topic is very limited. Following from an earlier study by Zhao, Scheider, and Thurman (2003), this research makes several contributions to the current literature. First, it includes additional years of data from police agencies receiving federal funding to examine the effects of additional resources on arrests. Second, making use of the two waves of census data (1990 and 2000) allowed time-varying analysis of the relationship between police arrests and demographics. Finally, a hierarchical statistical method for longitudinal analysis (HMLM) was used in the analysis of police arrest data from 5,871 cities during 1993 and 2000 when the involvement of federal government for promoting community policing or quality of life policing was unprecedented. Our primary findings suggest a positive relationship between COPS hiring grants and all four types of police arrests during the period of study though COPS funding usually accounted for only a small percentage of the total budget in a police department (GAO, 2005). More specifically, the hiring grant, the largest part of the COPS funding project, had consistently significant impact on police arrests after controlling for the socioeconomic variables and crimes. In addition, the hiring grant was significant predictor of all four categories of arrests, indicating that additional manpower did have a direct casual relationship with number of police arrests.