
Mercer University
UniversityMacon, United States
Research output, citation impact, and the most-cited recent papers from Mercer University (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Mercer University
The goal of the International HapMap Project is to determine the common patterns of DNA sequence variation in the human genome and to make this information freely available in the public domain. An international consortium is developing a map of these patterns across the genome by determining the genotypes of one million or more sequence variants, their frequencies and the degree of association between them, in DNA samples from populations with ancestry from parts of Africa, Asia and Europe. The HapMap will allow the discovery of sequence variants that affect common disease, will facilitate development of diagnostic tools, and will enhance our ability to choose targets for therapeutic intervention.
The birth of an intersex child prompts a long-term management strategy that involves a myriad of professionals working with the family. There has been progress in diagnosis, surgical techniques, understanding psychosocial issues and in recognizing and accepting the place of patient advocacy. The Lawson Wilkins Paediatric Endocrine Society (LWPES) and the European Society for Paediatric Endocrinology (ESPE) considered it timely to review the management of intersex disorders from a broad perspective, to review data on longer term outcome and to formulate proposals for future studies. The methodology comprised establishing a number of working groups whose membership was drawn from 50 international experts in the field. The groups prepared prior written responses to a defined set of questions resulting from an evidence based review of the literature. At a subsequent gathering of participants, a framework for a consensus document was agreed. This paper constitutes its final form.
The quest towards the integration of ultra-fast, high-precision optical clocks is reflected in the large number of high-impact papers on the topic published in the last few years. This interest has been catalysed by the impact that high-precision optical frequency combs (OFCs) have had on metrology and spectroscopy in the last decade [ [1] , [2] , [3] , [4] , [5] ]. OFCs are often referred to as optical rulers: their spectra consist of a precise sequence of discrete and equally-spaced spectral lines that represent precise marks in frequency. Their importance was recognised worldwide with the 2005 Nobel Prize being awarded to T.W. Hänsch and J. Hall for their breakthrough in OFC science [ 5 ]. They demonstrated that a coherent OFC source with a large spectrum – covering at least one octave – can be stabilised with a self-referenced approach, where the frequency and the phase do not vary and are completely determined by the source physical parameters. These fully stabilised OFCs solved the challenge of directly measuring optical frequencies and are now exploited as the most accurate time references available, ready to replace the current standard for time. Very recent advancements in the fabrication technology of optical micro-cavities [ 6 ] are contributing to the development of OFC sources. These efforts may open up the way to realise ultra-fast and stable optical clocks and pulsed sources with extremely high repetition-rates, in the form of compact and integrated devices. Indeed, the fabrication of high-quality factor (high-Q) micro-resonators, capable of dramatically amplifying the optical field, can be considered a photonics breakthrough that has boosted not only the scientific investigation of OFC sources [ [8] , [13] , [11] , [12] , [10] , [7] , [9] ] but also of optical sensors and compact light modulators [ [14] , [6] ]. In this framework, the demonstration of planar high-Q resonators, compatible with silicon technology [ [14] , [13] , [11] , [12] , [10] ], has opened up a unique opportunity for these devices to provide entirely new capabilities for photonic-integrated technologies. Indeed, it is well acknowledged by the electronics industry that future generations of computer processing chips will inevitably require an extremely high density of copper-based interconnections, significantly increasing the chip power dissipation to beyond practical levels [ [15] , [16] , [17] ]; hence, conventional approaches to chip design must undergo radical changes. On-chip optical networks, or optical interconnects, can offer high speed and low energy per-transferred-bit, and micro-resonators are widely seen as a key component to interface the electronic world with photonics. Many information technology industries have recently focused on the development of integrated ring resonators to be employed for electrically-controlled light modulators [ [14] , [15] , [16] , [17] ], greatly advancing the maturity of micro-resonator technology as a whole. Recently [ [13] , [11] , [12] ], the demonstration of OFC sources in micro-resonators fabricated in electronic (i.e. in complementary metal oxide semiconductor (CMOS)) compatible platforms has given micro-cavities an additional appeal, with the possibility of exploiting them as light sources in microchips. This scenario is creating fierce competition in developing highly efficient OFC generators based on micro-cavities which can radically change the nature of information transport and processing. Even in telecommunications, perhaps a more conventional environment for optical technologies, novel time-division multiplexed optical systems will require extremely stable optical clocks at ultra-high pulse repetition-rates towards the THz scale. Furthermore, arbitrary pulse generators based on OFC [ [18] , [19] ] are seen as one of the most promising solutions for this next generation of high-capacity optical coherent communication systems. This review will summarise the recent exciting achievements in the field of micro-combs, namely optical frequency combs based on high-Q micro-resonators, with a perspective on both the potential of this technology, as well as the open questions and challenges that remain.
STUDY DESIGN: Retrospective review study with literature review. OBJECTIVE: The goal of our current study is to raise awareness on complications associated with anterior cervical discectomy and fusion (ACDF) and their early detection and proper management. SUMMARY OF BACKGROUND DATA: It is known that ACDF constitutes one of the most commonly performed spinal procedures. Its outcome is quite satisfactory in the majority of cases. However, occasional complications can become troublesome, and in rare circumstances, catastrophic. Although there are several case reports describing such complications, their rate of occurrence is generally underreported, and data regarding their exact incidence in large clinical series are lacking. Meticulous knowledge of potential intraoperative and postoperative ACDF-related complications is of paramount importance so as to avoid them whenever possible, as well as to successfully and safely manage them when they are inevitable. METHODS: In a retrospective study, 1015 patients undergoing first-time ACDF for cervical radiculopathy and/or myelopathy due to degenerative disc disease and/or cervical spondylosis were evaluated. A standard Smith-Robinson approach was used in all our patients, while an autologous or allograft was used, with or without a plate. Operative reports, hospital and outpatient clinic charts, and radiographic studies were reviewed for procedure-related complications. Mean follow-up time was 26.4 months. RESULTS: The mortality rate in our current series was 0.1% (1 of 1015 patients, death occurred secondary to an esophageal perforation). Our overall morbidity rate was 19.3% (196 of 1015 patients). The most common complication was the development of isolated postoperative dysphagia, which observed in 9.5% of our patients. Postoperative hematoma occurred in 5.6%, but required surgical intervention in only 2.4% of our cases. Symptomatic recurrent laryngeal nerve palsy occurred in 3.1% of our cases. Dural penetration occurred in 0.5%, esophageal perforation in 0.3%, worsening of preexisting myelopathy in 0.2%, Horner's syndrome in 0.1%, instrumentation backout in 0.1%, and superficial wound infection in 0.1% of our cases. CONCLUSION: Meticulous knowledge of the ACDF-associated complications allows for their proper management. Postoperative dysphagia, hematoma, and recurrent laryngeal nerve palsy were the most common complications in our series. Management of complications was successful in the vast majority of our cases.
We have built a reliable and robust system that takes as input an astronomical image, and returns as output the pointing, scale, and orientation of that image (the astrometric calibration or World Coordinate System information). The system requires no first guess, and works with the information in the image pixels alone; that is, the problem is a generalization of the "lost in space" problem in which nothing—not even the image scale—is known. After robust source detection is performed in the input image, asterisms (sets of four or five stars) are geometrically hashed and compared to pre-indexed hashes to generate hypotheses about the astrometric calibration. A hypothesis is only accepted as true if it passes a Bayesian decision theory test against a null hypothesis. With indices built from the USNO-B catalog and designed for uniformity of coverage and redundancy, the success rate is >99.9% for contemporary near-ultraviolet and visual imaging survey data, with no false positives. The failure rate is consistent with the incompleteness of the USNO-B catalog; augmentation with indices built from the Two Micron All Sky Survey catalog brings the completeness to 100% with no false positives. We are using this system to generate consistent and standards-compliant meta-data for digital and digitized imaging from plate repositories, automated observatories, individual scientific investigators, and hobbyists. This is the first step in a program of making it possible to trust calibration meta-data for astronomical data of arbitrary provenance.
A meta-analysis of social desirability distortion compared computer questionnaires with traditional paper-and-pencil questionnaires and face-to-face interviews in 61 studies (1967— 1997; 673 effect sizes). Controlling for correlated observations, a near-zero overall effect size was obtained for computer versus paper-and-pencil questionnaires. With moderators, there was less distortion on computerized measures of social desirability responding than on the paper-and-pencil measures, especially when respondents were alone and could backtrack. There was more distortion on the computer on other scales, but distortion was small when respondents were alone, anonymous, and could backtrack. There was less distortion on computerized versions of interviews than on face-to-face interviews. Research is needed on nonlinear patterns of distortion, and on the effects of context and interface on privacy perceptions and on responses to sensitive questions. As computer and computer-based telecommunications technologies proliferate through society, increasingly they are being used to solicit information from people. Previ-ously existing clinical instruments, personality scales, job
We consider the situation when there is a large number of series, N, each with T observations, and each series has some predictive ability for some variable of interest. A methodology of growing interest is first to estimate common factors from the panel of data by the method of principal components and then to augment an otherwise standard regression with the estimated factors. In this paper, we show that the least squares estimates obtained from these factor-augmented regressions are consistent and asymptotically normal if . The conditional mean predicted by the estimated factors is consistent and asymptotically normal. Except when T/N goes to zero, inference should take into account the effect of “estimated regressors” on the estimated conditional mean. We present analytical formulas for prediction intervals that are valid regardless of the magnitude of N/T and that can also be used when the factors are nonstationary.
We examine the entry behavior of producers in different industries in different ex-port markets using a comprehensive dataset of French firms. These data reveal enormous heterogeneity, primarily within industries, in the nature of entry into different markets. Nonetheless, some striking regularities appear both across and within industries. The French data add a new dimension to an emerging empirical literature examining international trade at the level of individual producers. Andrew Bernard and J. Bradford Jensen (1995, 1999), Sofronis Clerides et al. (1998), and Bee Yan Aw et al. (2000), among others, have shown that: (i) exporters are typically in the minority; (ii) they tend to be more productive and larger; (iii) yet they usually export only a small fraction of their output. The findings that most firms do not export while those that do sell most of what they make at home suggest substantial barriers to exporting. Theories of producer export behavior have suggested either standard “iceberg ” costs, e.g., Bernard et al. (2003) or
This study compares the pre‐ and postprivatization financial and operating performance of 85 companies from 28 industrialized countries that were privatized through public share offerings for the period from 1990 through 1996. We document significant increases in profitability, output, operating efficiency, and dividend payments—and significant decreases in leverage ratios—for our full sample of firms after privatization, and for most subsamples examined. Capital expenditures increase significantly in absolute terms, but not relative to sales. Employment declines, but insignificantly. Combined with results from two previous, directly comparable studies, these findings strongly suggest that privatization yields significant performance improvements.
Mechanochemical liquid-assisted grinding (LAG) and sonochemical (SonicSlurry) techniques have been compared as methods to construct four model pharmaceutical cocrystals involving theophylline and caffeine as pharmaceutical ingredients and L-malic or L-tartaric acid as pharmaceutical cocrystal formers. For these model systems, the results are interpreted using the parameter η, the ratio of solvent volume to sample weight. Each if the four cocrystals was studied in four different solvents using LAG at η = 0.25 and 10 µL mg−1, as well as SonicSlurry experiments at η = 2, 6 and 12 µL mg−1. The formation of the cocrystal is observed in all standard LAG experiments when η = 0.25 µL mg−1. Cocrystal formation by neat grinding, i.e. with no liquid added, was observed only for the cocrystal of theophylline and L-malic acid. LAG experiments at very low η values (below 0.5 µL mg−1) revealed that the rate of cocrystal formation depended on the choice of the liquid and increases with η. SonicSlurry experiments performed at higher η values of 2, 6 and 12 µL mg−1 provided three different outcomes: the pure cocrystal, a mixture of the cocrystal with a cocrystal component, or a single cocrystal component. LAG experiments at η = 10 µL mg−1 produced results consistent with the SonicSlurry experiments at η = 12 µL mg−1. Measuring approximate solubilities of individual cocrystal components revealed that product formation is not dictated by the specific processing method but by saturation levels of reactants. An experimental approach based on approximate solubilities of cocrystal components has been developed to qualitatively predict the outcome of cocrystallization experiments at different η values. As a general guideline, cocrystal formation is expected under conditions in which all cocrystal components remain saturated.
BACKGROUND: Adenocarcinoma of the endometrium is the most common gynecologic malignancy in the United States, accounting for approximately 36,000 diagnoses of invasive carcinoma annually. The most common histologic type, endometrioid adenocarcinoma (EC), accounts for 75-80% of patients. The objective of this work was to estimate the prevalence of concurrent carcinoma in women with a biopsy diagnosis of the precursor lesion, atypical endometrial hyperplasia (AEH). METHODS: This prospective cohort study included women who had a community diagnosis of AEH. Diagnostic biopsy specimens were reviewed independently by three gynecologic pathologists who used International Society of Gynecologic Pathologists/World Health Organization criteria. Study participants underwent hysterectomy within 12 weeks of entry onto protocol without interval treatment. The hysterectomy slides also were reviewed by the study pathologists, and their findings were used in the subsequent analyses. RESULTS: Between November 1998 and June 2003, 306 women were enrolled on the study. Of these, 17 women were not included in the analysis: Two patients had unreadable slides because of poor processing or insufficient tissue, 2 patients had only slides that were not endometrial, the slides for 5 patients were not available for review, and 8 of the hysterectomy specimens were excluded because they showed evidence of interval intervention, either progestin effect or ablation. In total, 289 patients were included in the current analysis. The study panel review of the AEH biopsy specimens was interpreted as follows: 74 of 289 specimens (25.6%) were diagnosed as less than AEH, 115 of 289 specimens (39.8%) were diagnosed as AEH, and 84 of 289 specimens (29.1%) were diagnosed as endometrial carcinoma. In 5.5% (16 of 289 specimens), there was no consensus on the biopsy diagnosis. The rate of concurrent endometrial carcinoma for analyzed specimens was 42.6% (123 of 289 specimens). Of these, 30.9% (38 of 123 specimens) were myoinvasive, and 10.6% (13 of 123 specimens) involved the outer 50% of the myometrium. Among the women who had hysterectomy specimens with carcinoma, 14 of 74 women (18.9%) had a study panel biopsy consensus diagnosis of less than AEH, 45 of 115 women (39.1%) had a study panel biopsy consensus diagnosis of AEH, and 54 of 84 women (64.3%) had a study panel diagnosis of carcinoma. Among women who had no consensus in their biopsy diagnosis, 10 of 16 women (62.5%) had carcinoma in their hysterectomy specimens. CONCLUSIONS: The prevalence of endometrial carcinoma in patients who had a community hospital biopsy diagnosis of AEH was high (42.6%). When considering management strategies for women who have a biopsy diagnosis of AEH, clinicians and patients should take into account the considerable rate of concurrent carcinoma.
Understanding Trend and Cycle in Asset Values: Reevaluating the Wealth Effect on Consumption by Martin Lettau and Sydney C. Ludvigson. Published in volume 94, issue 1, pages 276-299 of American Economic Review, March 2004
Recent theory has predicted that if competing technologies operate under dynamic increasing returns, one, possibly inferior, technology will dominate the market. The history of nuclear power technology is used to illustrate these results. Light water is considered inferior to other technologies, yet it dominates the market for power reactors. This is largely due to the early adoption and heavy development by the U.S. Navy of light water for submarine propulsion. When a market for civilian power emerged, light water had a large head start, and by the time other technologies were ready to enter the market, light water was entrenched.
BACKGROUND: The US Preventive Services Task Force recently recommended screening all adult patients for obesity due in part to the strong association between obesity and numerous chronic diseases. However, how obesity affects health-related quality-of-life (HRQL), particularly for persons without any chronic diseases, is less clear. METHODS: The relationship between obesity and HRQL was examined using data from the 2000 Medical Expenditure Panel Survey. Respondents > or =18 years were classified as underweight, normal weight, overweight, class I obesity, and class II obesity based on their BMI. HRQL was measured by the 12-item Short Form physical and mental summary scores (PCS-12 and MCS-12, respectively) and EuroQol EQ-5D index and visual analogue scale (EQ VAS). The impact of obesity on HRQL was examined through multivariate regression, adjusting for sociodemographics and disease status. RESULTS: After adjustment, HRQL decreased with increasing level of obesity. Compared to normal weight respondents, persons with severe obesity had significantly lower scores with scores on the PCS-12, MCS-12, EQ-5D index, and EQ VAS being 4.0, 1.1, 0.073, and 4.8 points lower, respectively. Such decrements of HRQL for severe obesity were similar to the decrements seen for diabetes or hypertension. Persons with moderate obesity or who were overweight also had significantly lower HRQL scores, particularly on the PCS-12 and EQ-5D index. Underweight persons also had lower MCS-12 and EQ VAS scores. CONCLUSIONS: Persons with obesity had significantly lower HRQL than those who were normal weight and such lower scores were seen even for persons without chronic diseases known to be linked to obesity.
This study details the profile of 13 cell surface cluster differentiation markers on human reserve stem cells derived from connective tissues. Stem cells were isolated from the connective tissues of dermis and skeletal muscle derived from fetal, mature, and geriatric humans. An insulin/dexamethasone phenotypic bioassay was used to determine the identity of the stem cells from each population. All populations contained lineage-committed myogenic, adipogenic, chondrogenic, and osteogenic progenitor stem cells as well as lineage-uncommitted pluripotent stem cells capable of forming muscle, adipocytes, cartilage, bone, fibroblasts, and endothelial cells. Flow cytometric analysis of adult stem cell populations revealed positive staining for CD34 and CD90 and negative staining for CD3, CD4, CD8, CD11c, CD33, CD36, CD38, CD45, CD117, Glycophorin-A, and HLA DR-II.
Abstract The observation of electromagnetic radiation from radio to γ-ray wavelengths has provided a wealth of information about the Universe. However, at PeV (10 15 eV) energies and above, most of the Universe is impenetrable to photons. New messengers, namely cosmic neutrinos, are needed to explore the most extreme environments of the Universe where black holes, neutron stars, and stellar explosions transform gravitational energy into non-thermal cosmic rays. These energetic particles have millions of times higher energies than those produced in the most powerful particle accelerators on Earth. As neutrinos can escape from regions otherwise opaque to radiation, they allow an unique view deep into exploding stars and the vicinity of the event horizons of black holes. The discovery of cosmic neutrinos with IceCube has opened this new window on the Universe. IceCube has been successful in finding first evidence for cosmic particle acceleration in the jet of an active galactic nucleus. Yet, ultimately, its sensitivity is too limited to detect even the brightest neutrino sources with high significance, or to detect populations of less luminous sources. In this white paper, we present an overview of a next-generation instrument, IceCube-Gen2, which will sharpen our understanding of the processes and environments that govern the Universe at the highest energies. IceCube-Gen2 is designed to: (a) Resolve the high-energy neutrino sky from TeV to EeV energies (b) Investigate cosmic particle acceleration through multi-messenger observations (c) Reveal the sources and propagation of the highest energy particles in the Universe (d) Probe fundamental physics with high-energy neutrinos IceCube-Gen2 will enhance the existing IceCube detector at the South Pole. It will increase the annual rate of observed cosmic neutrinos by a factor of ten compared to IceCube, and will be able to detect sources five times fainter than its predecessor. Furthermore, through the addition of a radio array, IceCube-Gen2 will extend the energy range by several orders of magnitude compared to IceCube. Construction will take 8 years and cost about $350M. The goal is to have IceCube-Gen2 fully operational by 2033. IceCube-Gen2 will play an essential role in shaping the new era of multi-messenger astronomy, fundamentally advancing our knowledge of the high-energy Universe. This challenging mission can be fully addressed only through the combination of the information from the neutrino, electromagnetic, and gravitational wave emission of high-energy sources, in concert with the new survey instruments across the electromagnetic spectrum and gravitational wave detectors which will be available in the coming years.
The role of a dealer in securities markets is to provide liquidity on the exchange by quoting bid and ask prices at which he is willing to buy and sell a specific quantity of assets. Traditionally,...
ABSTRACT We investigate simultaneously the impact of promotion‐based tournament incentives for VPs and equity‐based (alignment) incentives for VPs and the chief executive officer (CEO) on firm performance. We find that tournament incentives, as measured by the pay differential between the CEO and VPs, relate positively to firm performance. The relation is more positive when the CEO nears retirement and less positive when the firm has a new CEO, and weakens further when the new CEO is an outsider. Our analysis is robust to corrections for endogeneity of all our incentive measures and to several alternative measures of tournament incentives and firm performance.
This paper makes projections of the growth in the car and total vehicle stock to the year 2015, for OECD countries and a number of developing economies, including China, India, and Pakistan. The projections are based on an econometrically estimated model that explains the growth of the car/population ratio (`car ownership') as a function of per-capita income; a similar model is used for vehicle ownership. The model estimations are based on annual data for 26 countries over the period 1960–1992; it is the first study to include countries covering the full range of income levels, from lowest to highest. The models are dynamically specified, so that short- and long-run income elasticities of car and vehicle ownership are estimated. These income elasticities depend upon per-capita income, ranging from about 2.0, for low- and middle-income levels (that is, ownership grows twice as fast as income), down to zero, as ownership saturation is approached for the highest income levels. The similarities and differences among countries are embodied within the model specification, and the implications for the projections are analyzed. ©
PURPOSE: Despite sincere commitment to egalitarian, meritocratic principles, subtle gender bias persists, constraining women's opportunities for academic advancement. The authors implemented a pair-matched, single-blind, cluster randomized, controlled study of a gender-bias-habit-changing intervention at a large public university. METHOD: Participants were faculty in 92 departments or divisions at the University of Wisconsin-Madison. Between September 2010 and March 2012, experimental departments were offered a gender-bias-habit-changing intervention as a 2.5-hour workshop. Surveys measured gender bias awareness; motivation, self-efficacy, and outcome expectations to reduce bias; and gender equity action. A timed word categorization task measured implicit gender/leadership bias. Faculty completed a work-life survey before and after all experimental departments received the intervention. Control departments were offered workshops after data were collected. RESULTS: Linear mixed-effects models showed significantly greater changes post intervention for faculty in experimental versus control departments on several outcome measures, including self-efficacy to engage in gender-equity-promoting behaviors (P = .013). When ≥ 25% of a department's faculty attended the workshop (26 of 46 departments), significant increases in self-reported action to promote gender equity occurred at three months (P = .007). Post intervention, faculty in experimental departments expressed greater perceptions of fit (P = .024), valuing of their research (P = .019), and comfort in raising personal and professional conflicts (P = .025). CONCLUSIONS: An intervention that facilitates intentional behavioral change can help faculty break the gender bias habit and change department climate in ways that should support the career advancement of women in academic medicine, science, and engineering.