1,622 research outputs found

    An Analysis of Poverty Convergence: Evidence from Pennsylvania Counties

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    This paper extends applications of unconditional and conditional β-convergence and σ-convergence analysis to poverty rates in a panel data sample of Pennsylvania counties during the period 1990-2019. Spatial structural breaks between rural and urban counties in Pennsylvania plus the possibility that Philadelphia County is an outlier are acknowledged to avoid spurious inferences. The findings support the existence of unconditional β-convergence in the pooled, urban, and rural samples with non-metropolitan areas exhibiting the greatest convergence. However, the largest conditional β-convergence is observed for urban counties, and this outcome is robust to the exclusion of Philadelphia County. Graphical evidence evinces a greater degree of σ-divergence in rural areas relative to the pooled and urban samples with metropolitan areas exhibiting neither convergence nor divergence in the absence of Philadelphia County. Statistical evidence based on ADF and DF-GLS tests reveals the presence of σ-divergence in the pooled and rural samples but weaker findings for the urban counties. Panel data tests for unit roots indicate σ-convergence for the full and rural samples but mixed results for the urban sample depending upon the test employed and whether Philadelphia County is included or not. The findings indicate that further investigation of tailored policy responses to poverty in different geographic areas within the same state is warranted

    Impact micro-positioning actuator

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    An impact micro-positioning actuator. In one aspect of the invention, a threaded shaft is threadably received in a nut and the nut is impacted by an impacting device, causing the nut first to rotate relative to the shaft by slipping as a result of shaft inertia and subsequently to stick to the shaft as a result of the frictional force therebetween. The nut is returned to its initial position by a return force provided by a return mechanism after impact. The micro-positioning actuator is further improved by controlling at least one and preferably all of the following: the friction, the impact provided by the impacting device, the return force provided by the return mechanism, and the inertia of the shaft. In another aspect of the invention, a threaded shaft is threadably received in a nut and the shaft is impacted by an impacting device, causing the shaft to rotate relative to the nut

    Communicating the Impacts of Potential Future Climate Change on the Expected Frequency of Extreme Rainfall Events in Cook County, Illinois

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    A novel methodology for determining future rainfall frequency is described in this report. Isohyetal maps illustrate how heavy precipitation may change in the future, but the results have a high level of uncertainty expressed as very wide confidence limits. Uncertainty in possible future conditions is much greater than the uncertainty identified for current commonly used precipitation analyses. The resulting isohyetal maps do not replace existing sources, such as Illinois State Water Survey (ISWS) Bulletin 70 (Huff and Angel, 1989) or National Oceanic and Atmospheric Administration (NOAA) Atlas 14 (Bonnin et al., 2006). Presently, the ISWS is updating Bulletin 70 (Huff and Angel, 1989) for subregions of Illinois. Some of these updates will include projected rainfall frequency. The key objectives of this study are to i) design a framework to translate future climate scenarios into a product that engineers and planners can use to quantify the impact of climate change, and ii) demonstrate how climate model output can be used to inform and plan adaptive strategies for stormwater and floodplain management. The framework in this study is illustrated using the observed and projected rainfall data in Cook County, Illinois, providing a road map to evaluate climate change impacts on urban flooding and a plan for adaptation. Numerous studies attempt to identify the implications of climate change with respect to hydrologic extremes (e.g., IPCC, 2007; CCSP, 2008; Milly et al., 2008). These studies project future climate conditions with more frequent extreme precipitation events in many regions around the world, including parts of the United States. In particular, it has been projected that northeastern Illinois, including the Chicago metropolitan area, will experience more frequent and more intense rainfall events in the future (Markus et al., 2012), which will lead to more intense and more frequent urban flooding events and to increased human, environmental, and economic risks. Thus, various planning and management measures need to be considered by urban communities which are responsible for administering ordinances governing the construction and maintenance of stormwater management systems, and for floodplain management to address public safety concerns, property damage, and economic interruption from intense precipitation. In these efforts, effective communication of climate change impacts on urban watersheds/sewer sheds is needed. Data should be delivered at the watershed level in a form that can be incorporated in watershed planning at the community level. Delivery of useful climate change information is critical for community planning and adaptation to changing climate conditions. It is common practice that future climate projections, which are based on global circulation models (GCM), are downscaled to finer temporal and spatial scales using statistical or dynamical downscaling models. However, watershed-scale climate data generated by climate models still do not provide precipitation data in a format useful for community engineers and planners to prepare, mitigate, and adapt to future conditions. Furthermore, city managers and decision makers need quantifiable future risk to demonstrate the need for adaptive actions, such as retrofitting storm sewers and other water conveyance structures or adopting higher regulatory design standards within the community. This is not offered by the present climate modeling outputs. In this research, a method is designed to analyze and express climate data in a format that can be readily used to assess future extreme precipitation events in models commonly used for sizing stormwater infrastructure and identifying flooding potential. In this method, future conditions climate data are analyzed to prepare precipitation maps for selected design storm frequencies which can be used to model future climate conditions of stormwater runoff and flood risk. This report presents a newly designed research framework to determine future conditions rainfall frequency maps, illustrating it in Cook County, Illinois, for the 24-hour duration rainfall event and for a range of recurrence intervals (also called return periods). Engineers commonly use these maps to determine the appropriate return period rainfall amount by interpolating between the isohyetals to evaluate options for storm and flood water management. Impacts of future climate conditions can then be convincingly demonstrated using conventional engineering to show changes in flooding frequency and extent, as well as damage comparisons associated with changing intense precipitation. Using standard and familiar models with future conditions precipitation scenarios facilitates communication of quantifiable future risk and supports community decision makers so they can plan, mitigate, and adapt to future conditions. This directly supports climate adaptation and mitigation by providing an understandable method for community engineers and planners to demonstrate the impact of climate change at the local level and develop specific adaptation strategies that will reduce future risk.published or submitted for publicationis peer reviewedOpe

    Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle

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    The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have the sensitivity to discover 2 R_E rocky planets within habitable zones and characterize their surfaces or atmospheres through spectrophotometry. Many more massive planets and debris discs will be imaged and characterized for the first time. With a 1.2m visible telescope, the proposed mission achieves its power by exploiting the most efficient and robust coronagraphic and wavefront control techniques. The Phase-Induced Amplitude Apodization (PIAA) coronagraph used by TOPS allows planet detection at 2 lambda/d with nearly 100% throughput and preserves the telescope angular resolution. An efficient focal plane wavefront sensing scheme accurately measures wavefront aberrations which are fed back to the telescope active primary mirror. Fine wavefront control is also performed independently in each of 4 spectral channels, resulting in a system that is robust to wavefront chromaticity.Comment: 12 pages, SPIE conference proceeding, May 2006, Orlando, Florid

    Rural-Urban Differences in Poverty: An Analysis of Pennsylvania Counties

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    This study examines the determinants of poverty in rural and urban Pennsylvania counties. Economic and demographic characteristics are evaluated in their relation to the poverty rate using panel data from 2000 to 2019 for the 67 Pennsylvania counties. A two-way fixed effects model is estimated to account for unobserved county-specific and time-specific heterogeneity. The results indicate that there are rural-urban differences in the impacts of explanatory variables. In rural Pennsylvania counties, economic factors have significant effects on the poverty rate. The percentage of employment in manufacturing and construction are negatively related to the poverty rate, while the percentage of renters and employment in agriculture are positively related. In contrast, only the percentage of female-headed households has a positive, statistically significant impact in urban counties. Oaxaca (1973) decomposition indicates that structural characteristics in rural counties help mitigate their poverty rates. The results suggest that different policies must be implemented in urban and rural counties to alleviate poverty

    A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex

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    Background: Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex. Methodology/Principal findings: We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7–9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4–5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype. Conclusions/Significance: Accumulation of pheromone appears to occur at different rates in the different chemotypes examined and results in differing amounts being present in glands over time. Release of accumulated pheromone is not passive, but depends on biotic (presence of females) and abiotic (light) circumstances. There are marked differences in content and release between the members of the complex suggesting important behavioural, biosynthetic and ecological differences between them. Author summary: The Dipteran subfamily Phlebotominae includes the genera Lutzomyia and Phlebotomus among which several species are important vectors of parasitic and bacterial pathogens. The sand fly Lutzomyia longipalpis is considered the main vector of visceral leishmaniasis (VL) in the New World. Based on the main component of the male sex-aggregation pheromone gland, different sex pheromone-producing populations (chemotypes) of L. longipalpis are recognized in Brazil. Given the importance of the sex-aggregation pheromones in the biology of this species complex, we present here the first attempt to study how pheromone accumulates in the glands over time and factors that might influence its release in the three most common chemotypes from Brazil. Our results demonstrated that pheromone first starts to accumulate a few hours post-eclosion (6–12 h) and this continues over 15 days. Pheromone release is a dynamic process which varies between the 3 chemotypes depending on biotic factors, such as light regime and presence/absence of conspecific females. This work provides valuable information, critical to our understanding of the behaviour and ecology of L. longipalpis sand flies and which will contribute to investigations to improve field-based pheromone control and monitoring of L. longipalpis sand flies

    Pyrene binary probes for unambiguous detection of mRNA using time-resolved fluorescence spectroscopy

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    We report here the design, synthesis and application of pyrene binary oligonucleotide probes for selective detection of cellular mRNA. The detection strategy is based on the formation of a fluorescent excimer when two pyrene groups are brought into close proximity upon hybridization of the probes with the target mRNA. The pyrene excimer has a long fluorescence lifetime (>40 ns) compared with that of cellular extracts (∼7 ns), allowing selective detection of the excimer using time-resolved emission spectra (TRES). Optimized probes were used to target a specific region of sensorin mRNA yielding a strong excimer emission peak at 485 nm in the presence of the target and no excimer emission in the absence of the target in buffer solution. While direct fluorescence measurement of neuronal extracts showed a strong fluorescent background, obscuring the detection of the excimer signal, time-resolved emission measurements indicated that the emission decay of the cellular extracts is ∼8 times faster than that of the pyrene excimer probes. Thus, using TRES of the pyrene probes, we are able to selectively detect mRNA in the presence of cellular extracts, demonstrating the potential for application of pyrene excimer probes for imaging mRNAs in cellular environments that have background fluorescence

    Humoral immune response to COVID-19 mRNA vaccines in patients with relapsing multiple sclerosis treated with ofatumumab

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    BACKGROUND: There are limited data available regarding the impact of ofatumumab, an anti-CD20 B-cell-depleting monoclonal antibody for relapsing multiple sclerosis (RMS), on vaccination response. The study objective was to assess humoral immune response (HIR) to non-live coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccination in patients with RMS treated with ofatumumab. METHODS: This was an open-label, single-arm, multicenter, prospective pilot study of patients with RMS aged 18-55 years who received 2 or 3 doses of a COVID-19 mRNA vaccine after ≥1 month of subcutaneous ofatumumab (20 mg/month) treatment. The primary endpoint was the proportion of patients achieving HIR, as defined by local laboratory severe acute respiratory syndrome coronavirus-2 qualitative immunoglobulin G assays. Assay No. 1 was ≥14 days after the second or third vaccine dose. Assay No. 2 was 90 days thereafter. RESULTS: Of the 26 patients enrolled (median [range] age: 42 [27-54] years; median [range] ofatumumab treatment duration: 237 [50-364] days), HIR was achieved by 53.9% (14/26; 95% CI: 33.4 - 73.4%) at Assay No. 1 and 50.0% (13/26; 95% CI: 29.9 - 70.1%) at Assay No. 2. Patients who received 3 vaccine doses had higher HIR rates (Assay No. 1: 70.0% [7/10]; Assay No. 2: 77.8% [7/9]) than those who received 2 doses (Assay No. 1: 46.7% [7/15]; Assay No. 2: 42.9% [6/14]). Of patients aged \u3c40 years without previous anti-CD20 therapy, HIR was achieved by 90.0% (9/10) at Assay No. 1 and 75.0% (6/8) at Assay No. 2. No serious adverse events were reported. CONCLUSION: Patients with RMS treated with ofatumumab can mount HIRs following COVID-19 vaccination. A plain language summary, infographic and a short video summarizing the key results are provided in supplementary material. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT04847596 (https://clinicaltrials.gov/ct2/show/NCT04847596)
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