Simple Panel Research Articles

Can Development Aid Help Promote Foreign Direct Investment? Evidence from Central Asia

AbstractThere is a continuing debate on the effectiveness of development aid. One less obvious angle on this issue is the question of the likely impact of aid on foreign direct investment (FDI). This paper tests whether aid had any impact on incoming FDI in Central Asian economies during the period 1993–2008. A simple panel model suggests that (a) aid had a moderate complementary effect on inward FDI, (b) there was a crowding‐out effect such that domestic investment reduced FDI stocks, (c) natural resources were a key attraction for private capital, and (d) increases in development aid offset the crowding‐out effect of domestic capital on FDI. It is argued that donors should target aid to enhance the climate for inward investment.

Generalized Difference in Differences With Panel Data and Least Squares Estimator

With one treated and one untreated periods, difference in differences (DD) requires the untreated response changes to be the same across the treatment and control groups, if the treatment were withheld contrary to the fact. A natural way to check the condition is to backtrack one period and examine the response changes in two pretreatment periods. If the condition does not hold in the pretreatment periods, then a modified DD takes the form of “generalized difference in differences (GDD),” which is a triple difference (TD) with one more time-wise difference than DD. GDD generalizes DD with a weaker identification condition in the sense that a time-constant, but not necessarily zero, time/selection effect is allowed. One more time-wise differencing (quadruple difference [QD]) than GDD allows for the time/selection effect even to change over time, which makes it possible to test for the GDD identification condition. Simple panel least squares estimators (LSEs)/tests for DD and GDD are proposed and an empirical illustration is presented.

Oropharyngeal squamous cell carcinoma (OPSCC), a practical prognostic immunophenotypic panel

Aims Human papillomavirus (HPV)-positive OPSCC accounts for 25% of OPSCC. HPV E6 and E7 proteins inactivate the retinoblastoma gene causing overexpression of the p16 protein, which is regarded as HPV surrogate. There is evidence that p16 expression is an independent prognostic factor and cyclin D1 overexpression associated with poor prognosis in OPSCC. HPV+ OPSCC carries better prognosis than HPV–OPSCC, and is characterised by histological poor squamous differentiation (PD) and advanced regional nodal metastasis. This study aimed to study correlation among the morphology, immunophenotype and HPV DNA in OPSCC. Methods The morphology, immunophenotype and HPV DNA in OPSCC of 147 patients in Hong Kong were studied, using an immunoautostainer (p16 and cyclin D1), polymerase chain reaction and typing by sequencing for HPV DNA detection. Results Twenty-seven (18%) tumours carried HPV16 DNA, 56 (38%) were p16+ and 105 (72%) cyclin D1+. Fifty-two (35%) were PD tumours. Strong statistical correlation (p Discussion This study showed that p16 is strongly correlated with the good prognostic feature PD, while cyclin D1 is correlated with the poor prognostic features p16– and HPV DNA–. We conclude a simple immunophenotypic panel of p16 and cyclin D1 is a practical approach for prognostication of HPV+ OPSCC.

Fatigue Behaviour of Full Scale Flat Stiffened Aeronautic Panels

This paper concerns the experimental characterization of static and fatigue strength of a flat panel stiffened by bonded pad made of aluminum alloy. The panels were full scale and tested under both static and fatigue loads, applied by means of an in house designed and built multi-axial static and fatigue machine. The fatigue crack propagation life of the stiffened panel has been compared to that of a simple flat panel and to that of a flat panel with chemical milling pad-up, getting that the fatigue crack growth life can be significantly improved.

Evaluation of a regional monitoring program's statistical power to detect temporal trends in forest health indicators.

Forests are socioeconomically and ecologically important ecosystems that are exposed to a variety of natural and anthropogenic stressors. As such, monitoring forest condition and detecting temporal changes therein remain critical to sound public and private forestland management. The National Parks Service's Vital Signs monitoring program collects information on many forest health indicators, including species richness, cover by exotics, browse pressure, and forest regeneration. We applied a mixed-model approach to partition variability in data for 30 forest health indicators collected from several national parks in the eastern United States. We then used the estimated variance components in a simulation model to evaluate trend detection capabilities for each indicator. We investigated the extent to which the following factors affected ability to detect trends: (a) sample design: using simple panel versus connected panel design, (b) effect size: increasing trend magnitude, (c) sample size: varying the number of plots sampled each year, and (d) stratified sampling: post-stratifying plots into vegetation domains. Statistical power varied among indicators; however, indicators that measured the proportion of a total yielded higher power when compared to indicators that measured absolute or average values. In addition, the total variability for an indicator appeared to influence power to detect temporal trends more than how total variance was partitioned among spatial and temporal sources. Based on these analyses and the monitoring objectives of the Vital Signs program, the current sampling design is likely overly intensive for detecting a 5 % trend·year(-1) for all indicators and is appropriate for detecting a 1 % trend·year(-1) in most indicators.

The Impact of Right to Carry Laws and the NRC Report: The Latest Lessons for the Empirical Evaluation of Law and Policy

For over a decade, there has been a spirited academic debate over the impact on crime of laws that grant citizens the presumptive right to carry concealed handguns in public – so-called right-to-carry (RTC) laws. In 2004, the National Research Council (NRC) offered a critical evaluation of the “More Guns, Less Crime” hypothesis using county-level crime data for the period 1977-2000. 15 of the 16 academic members of the NRC panel essentially concluded that the existing research was inadequate to conclude that RTC laws increased or decreased crime. One member of the panel thought the NRC's panel data regressions showed that RTC laws decreased murder, but the other 15 responded by saying that “the scientific evidence does not support” that position. We evaluate the NRC evidence, and improve and expand on the report’s county data analysis by analyzing an additional six years of county data as well as state panel data for the period 1979-2010. We also present evidence using both a more plausible version of the Lott and Mustard specification, as well as our own preferred specification (which, unlike the Lott and Mustard model presented in the NRC report, does control for rates of incarceration and police). While we have considerable sympathy with the NRC’s majority view about the difficulty of drawing conclusions from simple panel data models and re-affirm its finding that the conclusion of the dissenting panel member that RTC laws reduce murder has no statistical support, we disagree with the NRC report’s judgment on one methodological point: the NRC report states that cluster adjustments to correct for serial correlation are not needed in these panel data regressions, but our randomization tests show that without such adjustments the Type 1 error soars to 22-73 percent. Our paper highlights some important questions to consider when using panel data methods to resolve questions of law and policy effectiveness. We buttress the NRC’s cautious conclusion regarding the effects of RTC laws by showing how sensitive the estimated impact of RTC laws is to different data periods, the use of state versus county data, particular specifications (especially the Lott-Mustard inclusion of 36 highly collinear demographic variables), and the decision to control for state trends. Across the basic seven Index I crime categories, the strongest evidence of a statistically significant effect would be for aggravated assault, with 11 of 28 estimates suggesting that RTC laws increase this crime at the .10 confidence level. An omitted variable bias test on our preferred Table 8a results suggests that our estimated 8 percent increase in aggravated assaults from RTC laws may understate the true harmful impact of RTC laws on aggravated assault, which may explain why this finding is only significant at the .10 level in many of our models. Our analysis of the year-by-year impact of RTC laws also suggests that RTC laws increase aggravated assaults. Our analysis of admittedly imperfect gun aggravated assaults provides suggestive evidence that RTC laws may be associated with large increases in this crime, perhaps increasing such gun assaults by almost 33 percent. In addition to aggravated assault, the most plausible state models conducted over the entire 1979-2010 period provide evidence that RTC laws increase rape and robbery (but usually only at the .10 level). In contrast, for the period from 1999-2010 (which seeks to remove the confounding influence of the crack cocaine epidemic), the preferred state model (for those who accept the Wolfers proposition that one should not control for state trends) yields statistically significant evidence for only one crime – suggesting that RTC laws increase the rate of murder at the .05 significance level. It will be worth exploring whether other methodological approaches and/or additional years of data will confirm the results of this panel-data analysis and clarify some of the highly sensitive results and anomalies (such as the occasional estimates that RTC laws lead to higher rates of property crime) that have plagued this inquiry for over a decade.

Models and comparisons for the evaluation of the sound transmission loss of panels

The purpose of this work is to present the numerical evaluation of the sound transmission loss of some simple panel configurations and to compare them to the theoretical and experimental data found in existing literature. The numerical evaluations are carried out through the commercial software VA-One®. Specifically, single and double panels of different materials and configurations are investigated and thus the possibility to build good predictive numerical models is verified. The panels refer to the common automotive and aerospace configurations. An analysis of foam lined panels is presented, too. The numerous test cases can be considered as benchmarks for the simulations obtained with the statistical energy analysis. The agreements are very good and thus, statistical energy analysis represents a mature predictive methodology for this kind of simulations. Nevertheless, some care is always needed to select among the different simulation strategies for given specific configurations. The results are eventually cross-compared in order to highlight the configurations which are more promising for further investigations; this has been done by introducing a dimensionless frequency.

Less poverty, more emigration: understanding migrant flows from developing countries

This paper examines the relationship between economic development in less-developed migrant-sending countries and migrant flows from those countries to the developed countries. The study is motivated by the misconception that there is a linear relationship between the level of economic development and emigration from developing countries. The misconception often leads to the argument that helping to improve the general economic conditions in poor countries would reduce the rates of emigration from those countries to the developed world. Using the UK as a typical migrant-receiving developed country, the paper employs simple panel data methods to study the migrant inflows from 48 developing countries in Africa, Asia and South and Central America over a period of 33 years (1973–2005). The study finds that there is an inverse U-shaped relationship between economic development and emigration from developing countries to the UK, though this relationship is sensitive to aggregation of countries.

Renal Oncocytoma and Cromophobe Renal Cell Carcinoma: Main Morphological Differences and Proposal of a Simple Histochemical and Immunohistochemical Panel to separate them

Introduction: Renal Oncocytoma (RO) and Chromophobe Renal Cell Carcinoma (ChCCR) are within spectrum of “eosinophilic renal neoplasms” that can share morphological features. In some instances, it can be challenging differentiate both entities based only on the HE. For this reason, complementary ancillary techniques are needed. Methodology: Sixteen RO cases and 21 ChCCR cases were evaluated for macroscopic and microscopic features, defining their architectural, nuclear and special stains criterion. Hale`s Coloidal Iron (HCI), Citokeratin 7 and CD15 were performed. Results: Significant (p<.001) morphological differences were the pattern of grown (16/16 RO nested type vs 19/21 ChCCR diffuse type), nuclear morphology (“raisinoid” nuclei: 0/16 RO vs. 19/21 ChRCC) and presence of mitotic figure (0/16 RO vs. 16/21 ChCCR). Special stains showed that HCI was positive in 2/16 cases of RO and 20/21 of ChCCR, CK7 was positive in 1/16 cases of RO and 18/21 of ChCCR and CD15 was positive in 13/16 RO and 4/21 of ChCCR (p<.001). Conclusion: Main differences beetwen RO and ChCCR are respectively the pattern of grown (nested/diffuse), raisinoid nucleus (-/+), and presence of mitosis (-/+). Besides ancillary techniques show HCH (-/+), CK7 (-/+) and CD15 (+/-). The ancillary panel of stains is very easy to perform and useful to achieve the correct diagnosis.

Immunohistochemistry of soft tissue tumours – review with emphasis on 10 markers

Immunohistochemistry is an integral component in the proper analysis of soft tissue tumours, and a simple panel of six markers is useful in practical triage: CD34, desmin, epithelial membrane antigen (EMA), keratin cocktail AE1/AE3, S100 protein and alpha smooth muscle actin (SMA). These markers frequently assist in the differential diagnosis of fibroblastic, myoid, nerve sheath and perineurial cell tumours, synovial and epithelioid sarcoma and others. However, they all are multispecific, so that one has to be cognizant of their distribution in normal and neoplastic tissues. Four additional useful markers for specific tumour types are discussed here: CD31 and ERG for vascular endothelial tumours, and KIT and DOG1/Ano-1 for gastrointestinal stromal tumours (GISTs). However, hardly any marker is totally monospecific for any one type of tumour. Furthermore, variably lineage-specific markers do not usually distinguish between benign and malignant proliferations, so that this distinction has to be made on histological grounds. Immunohistochemical evaluation is most useful, efficient and cost-effective when used in the context of careful histological evaluation by an experienced pathologist, aware of all diagnostic entities and their histological spectra. Additional diagnostic steps that must be considered in difficult cases include clinicoradiological correlation and additional sampling of remaining wet tissue, if possible.

A Simple Panel Unit-Root Test with Smooth Breaks in the Presence of a Multifactor Error Structure

This paper proposes a new simple panel unit-root test by extending the cross-sectionally augmented panel unit-root test (CIPS) developed by Pesaran et al. (2013) to allow for smoothing structural changes in deterministic terms, approximated by a Fourier series. The proposed statistic is the simple average of the individual statistics constructed from the breaks and cross-sectional dependence augmented Dickey-Fuller (BCADF) regression and is called the BCIPS statistic. We initially develop the tests by assuming that the number of factors in the model is known and show that the limiting distribution of the BCADF statistic is free of nuisance parameters. The nonstandard limiting distribution of the (truncated) BCIPS statistic is also shown to exist and its critical values are tabulated. Monte-Carlo experiments point out that the sizes and powers of the BCIPS statistic are generally satisfactory as long as T is greater than or equal to fifty and a hundred, respectively. By using two different methods to determine the number of factors, both the BCIPS and CIPS tests are applied to examine the validity of long-run purchasing power parity. The proposed test complements the panel unit-root tests with breaks using dummy variables.

Shape control of multi-cellular inflatable panels

Multi-cellular inflatable structures are ultralight and robust against membrane damage such as pinholes caused by space debris. Due to their robustness, inflatable structures supported by inner gases can be applied as space structures. In the present study, shape control for a simple multi-cellular inflatable panel was achieved via a novel diaphragm mechanism. When the bending actuator in a center membrane bends, the inner pressures of sub-cells become different, and the diaphragm mechanism bends as a whole. Because a sliding component is not included, this deformable system is a reliable mechanism. In addition, the proposed mechanism has higher rigidity than that of a bending actuator used alone. In the present paper, we investigate the feasibility of a novel diaphragm mechanism and its characteristics using experimental and numerical results.

Optical schemes for speckle suppression by Barker code diffractive optical elements

A method for speckle suppression based on Barker code and M-sequence code diffractive optical elements (DOEs) is analyzed. An analytical formula for the dependence of speckle contrast on the wavelength of the laser illumination is derived. It is shown that speckle contrast has a wide maximum around the optimal wavelength that makes it possible to obtain large speckle suppression by using only one DOE for red, green, and blue laser illumination. Optical schemes for implementing this method are analyzed. It is shown that the method can use a simple liquid-crystal panel for phase rotation instead of a moving DOE; however, this approach requires a high frequency of liquid-crystal switching. A simple optical scheme is proposed using a 1D Barker code DOE and a simple 1D liquid-crystal panel, which does not require a high frequency of liquid-crystal switching or high-accuracy DOE movement.

Mimicry of sugar tumor and minute pulmonary meningothelial-like nodule to metastatic lung deposits in a patient with rectal adenocarcinoma

Several reports have described different lung lesions mimicking primary or metastatic neoplasms. In this paper, we describe the different features of two uncommon and benign lung lesions mimicking metastasis from a primary large bowel adenocarcinoma. Our patient is a 75-year old female with a history of invasive rectal adenocarcinoma. One month after her surgery, she started complaining of coughing and shortness of breath. Clear cell sugar tumor and minute meningothelial-like nodules had been found incidentally and simultaneously during her chest x-ray. The diagnosis had been made based on morphology and was supported by a positive staining to a panel of immunohistochemical stains including CD34, vimentin, HMB45, melan A and S100. An ultra-structural examination was also performed and confirmed the presence of melanosomes in sugar tumor. The coexistence of lung sugar tumor and minute pulmonary meningothelial-like nodules has never been reported in the literature and an awareness of these lesions is essential to correctly diagnose and stage patients.

Evaluation of plasma proteomic data for Alzheimer disease state classification and for the prediction of progression from mild cognitive impairment to Alzheimer disease.

Previous studies that have examined the potential for plasma markers to serve as biomarkers for Alzheimer disease (AD) have studied single analytes and focused on the amyloid-β and τ isoforms and have failed to yield conclusive results. In this study, we performed a multivariate analysis of 146 plasma analytes (the Human DiscoveryMAP v 1.0 from Rules-Based Medicine) in 527 subjects with AD, mild cognitive impairment (MCI), or cognitively normal elderly subjects from the Alzheimer's Disease Neuroimaging Initiative database. We identified 4 different proteomic signatures, each using 5 to 14 analytes, that differentiate AD from control patients with sensitivity and specificity ranging from 74% to 85%. Five analytes were common to all 4 signatures: apolipoprotein A-II, apolipoprotein E, serum glutamic oxaloacetic transaminase, α-1-microglobulin, and brain natriuretic peptide. None of the signatures adequately predicted progression from MCI to AD over a 12- and 24-month period. A new panel of analytes, optimized to predict MCI to AD conversion, was able to provide 55% to 60% predictive accuracy. These data suggest that a simple panel of plasma analytes may provide an adjunctive tool to differentiate AD from controls, may provide mechanistic insights to the etiology of AD, but cannot adequately predict MCI to AD conversion.

Precast fiber reinforced cementitious composites for seismic retrofit of deficient rc joints – A pilot study

The objective of this study was to investigate the seismic behavior of deficient reinforced concrete exterior beam–column joints constructed with low-strength concrete and plain reinforcing bars before and after retrofitting with prefabricated HPFRCC (high-performance fiber-reinforced cementitious composite) panels. For this purpose, four full-scale beam–column–slab–transverse beam sub-assemblies were tested under constant column axial load and reversed static cyclic lateral loads. Before these full-scale tests, four simple panel specimens, which were built to represent the joint cores, were also tested under diagonal tension before and after retrofitting with prefabricated HPFRCC panels. Both types of tests showed that retrofitting with prefabricated HPFRCC panels provided considerable enhancement, both in strength and in displacement capacity, provided that the panels were properly anchored to the joint core and the slippage of the beam longitudinal bars in the joint core was prevented. In the analytical part of the study, the strengths of the reference and retrofitted panels, tested under diagonal tension, were predicted quite accurately using non-linear finite element analysis. Furthermore, Mohr’s circle and strut-and-tie modeling was used to obtain the complete load–displacement relationships of the reference and retrofitted joint sub-assemblies.

Numerical analysis of cavitating propeller and pressure fluctuation on ship stern using a simple surface panel method “SQCM”

This paper presents a calculation method for the pressure fluctuation induced by a cavitating propeller. This method consists of two steps: the first step is the calculation of propeller sheet cavitation, and the second step is the calculation of pressure fluctuation on the ship stern. It is for practicality that we divide the method into two steps but do not calculate these steps simultaneously. This method is based on a simple surface panel method “SQCM” which satisfies the Kutta condition easily. The SQCM consists of Hess and Smith type source panels on the propeller or cavity surface and discrete vortices on the camber surface according to Lan’s QCM (quasi-continuous vortex lattice method). In the first step, the cavity shape is solved by the boundary condition based on the free streamline theory. In order to get the accurate cavity shape near the tip of the propeller blade, the cross flow component is taken into consideration on the boundary condition. In the second step, we calculate the cavitating propeller and the hull surface flow simultaneously so as to calculate the pressure fluctuation including the interaction between the propeller and the hull. At that time, the cavity shape is changed at each time step using the calculated cavity shape gotten by the first step. Qualitative agreements are obtained between the calculated results and the experimental data regarding cavity shape, cavity volume and low order frequency components of the pressure fluctuation induced by the cavitating propeller.

Detection of Different β-Lactamases and their Co-existence by Using Various Discs Combination Methods in Clinical Isolates of Enterobacteriaceae and Pseudomonas spp.

Background:Resistance to broad spectrum beta-lactams mediated by extended spectrum β-lactamase (ESBL), AmpC, and metallobetalactamase (MBLs) enzymes are an increasing problem worldwide. The study was aimed to detect occurrence rate and to evaluate different substrates and inhibitors by disc combination method for detecting varying degree of β-lactamase enzymes and their co-production.Materials and Methods:A disc panel containing imipenem (IMP), IMP/EDTA, ceftazidime (CA), ceftazidime-tazobactum (CAT), CAT/cloxacillin (CLOX), ceftazidime-clavulanic acid (CAC), CAC/CLOX, cefoxitin (CN), and CN/CLOX in a single plate was used to detect presence of ESBLs, AmpC, and MBLs and/or their co-existence in 184 consecutive, nonrepetitive, clinical isolates of Enterobacteriace (n = 96) and Pseudomonas spp. (n = 88) from pus samples of hospitalized patients, resistant to 3rd generation cephalosporins.Results:Out of a total of 96 clinical isolates of Enterobacteriaceae, 18.7, 20.8, and 27% were pure ESBL, AmpC, and MBL producers, respectively. ESBL and AmpC were co-produced by 25% isolates. Among 88 Pseudomonas spp. 38.6, 13, and 6% were pure MBL, ESBL, and AmpC producers, respectively. ESBL/AmpC and MBL/AmpC co-production was seen in 20% and 18% isolates, respectively. Among ESBL and AmpC co-producers, CA/CAC/CLOX disc combination (DC) missed 7 of the 24 ESBL producers in Enterobacteriace and 4 of the 18 ESBL in Pseudomonas spp., which were detected by CA/CAT/CLOX DC. No mechanism was detected among 8.3% Enterobacteriaceae and 2.3% Pseudomonas isolates.Conclusion:Diagnostic problems posed by co-existence of different classes of β-lactamases in a single isolate could be solved by disc combination method by using simple panel of discs containing CA, CAT, CAT/CLOX, IMP, and IMP/EDTA.

Metastatic Melanoma Presenting as an Isolated Breast Tumor: A Study of 20 Cases With Emphasis on Several Primary Mimickers

The mammary gland can be a site of metastasis in patients with malignant melanoma, which is easily recognized microscopically if clinical information is available. Nonetheless, metastatic melanoma presenting as an isolated mammary tumor can be more challenging to diagnose because it can simulate a primary breast carcinoma clinically and morphologically. To review metastatic melanoma to the breast, presenting as primary breast carcinomas clinically and morphologically. The authors report 20 cases of metastatic melanoma clinically presenting as breast tumors. Cases with widespread metastatic presentation were excluded. Epithelioid and spindle cell tumors predominated, suggesting mammary ductal, papillary, or sarcomatoid carcinoma. Most cases (16 of 20) were submitted for consultation or second opinion owing to their unusual presentation in the breast, or to perform predictive/prognostic immunohistochemical assays. Seven cases had a remarkable phenotypic spectrum expanding the differential diagnosis to large cell lymphoma, leiomyosarcoma, medullary carcinoma, malignant schwannoma, and liposarcoma. Tumor cells were negative for cytokeratin stains and positive for S100 protein, HMB-45, and Melan-A. Negative staining was also observed for epithelial membrane antigen, CD45, desmin, estrogen and progesterone receptors, and human epidermal growth factor receptor 2. Metastatic melanoma may simulate a broad spectrum of primary breast malignancies. Although the application of a simple panel of antibodies assists in rendering the correct interpretation, lesions presenting as isolated breast tumors may introduce a significant diagnostic difficulty, especially when there is inadequate patient history and/or limited biopsy material. Further challenges are introduced by the extraordinary phenotypic plasticity of metastatic melanoma. Awareness of this pattern variance is essential to avoid inappropriate treatment, especially in cases simulating a "triple negative," poorly differentiated carcinoma of the breast.

A Panel Unit-Root Test with Smooth Breaks and Cross-Sectional Dependence

This paper develops a simple panel unit-root test that accommodates cross-sectional dependence among variables and smooth structural changes in deterministic components. The proposed test is the simple average of the individual statistics constructed from the breaks and cross-sectional dependence augmented Dickey-Fuller (BCADF) regression. Applying the sequential limit approach, this paper shows that the asymptotic distribution of the BCADF statistic is free of nuisance parameters as N, T go to infinity. We also extend our analysis to the case where shocks are serially correlated. The limiting distribution of the average BCADF statistic is shown to exist and its critical values are tabulated. Monte-Carlo experiments point out that the size and power of the average BCADF statistic are generally good as long as T is greater than fifty. The test is then applied to examine the validity of long-run purchasing power parity.