139 research outputs found
The Changing Dynamics of the Employment Gap and its Macroeconomic Implications
There has been much discussion about the sluggish economic recovery out of the recent recession. However, the lag in employment growth is not unique to the most recent recovery. Jobless recoveries have plagued the U.S. economy over the last three business cycles. The reasons for this change have remained largely inconclusive, with several factors highlighted in the current literature. This paper uses Vector Autoregression (VAR) to analyze the employment gap in the United States over the past six decades. Unlike previous studies, it accounts for the most recent recession while also addressing alternative explanations - trade and globalization, government employment, the housing market, and the sectoral mix of the U.S. economy – within the context of business cycle economic theory. This study finds evidence that performance in the housing and the import sectors, as well as the industrial mix of the economy have a significant impact on the size of the employment gap in the United States. To a lesser extent, it finds that fluctuations in government spending and productivity also influence the size of the employment gap
Use of 5-(Perylen-3-yl)Ethynyl-arabino-Uridine (aUY11) to inactivate Rift Valley fever virus and preserve neutralization epitopes
Rift Valley fever (RFV) is a mosquito-borne disease, endemic to Africa, and known to cause abortion in animals and hemorrhagic fever in humans. All enveloped viruses require the fusion of viral membranes with cellular membranes to enter into and replicate inside the host cell. These viruses have a universal objective: find the cell receptors that match the viral attachment proteins and use those to gain access to the cell membrane. The use of aUY11, a monosaccharide (sugar)-based compound, has previously shown to effectively use a biophysical approach in the inhibition of viral fusion of other enveloped viruses1. In this study, we attempt to use aUY11 to inhibit the fusion of Rift Valley fever virus (RVFV) in vitro as a primary step in the creation of an FDA-approved vaccination for humans and animals to protect against often-lethal RVFV infection. We show here that aUY11 inhibits viral replication in Vero 76 cells and therefore has potential as an RVFV vaccine
Case study: Lead contamination in soil and plants of a Metro Atlanta home
INTRODUCTION: Lead contamination in housing developments of the Metro Atlanta Area has prompted the US Environmental Protection Agency (EPA) to establish the Westside Lead Superfund Site for soil and plant remediation efforts. As a result, affected residents have to review their own health and wellness in a different perspective due to the possibility of having lead contamination. No quantity of lead is considered safe in the human body, especially since it is known to compete with the functionality of calcium in many vital biological processes. Manufacturing and disposal procedures in lead-based industries have contributed to lead contamination of soil and water. This especially occurs along railroads where historic operations involved the transport of industrial products containing heavy metals. These transportation routes are found to have elevated levels of heavy metals due to normal train operations, but in some cases the practice of dumping waste into a railroad’s easement has created areas of significant lead contamination. It is possible for these past railroad easements to transition into residential areas, which is the case for one Metro Atlanta home north of the Westside Atlanta Superfund site. Testing of this residence found significant levels of lead contamination, especially where they grew their own produce. Due to the elevated concentration of lead, the EPA has reported to this resident that removal of the soil is recommended.
OBJECTIVES: The goal of this study is to conduct soil and plant sample analysis for lead contamination in a Metro Atlanta residence to observe for possible lead propagation into plants in partnership with the Saikawa Lab of Emory University.
METHODS: Soil and plant samples are collected and prepared for evaluation of lead contamination through inductively coupled plasma mass spectrometry (ICP-MS). Lead naturally occurs in soil with an average geologic concentration of 10-30 ppm. If levels exceed the average geologic concentration, caution should be considered because it indicates that lead was added by exogenous sources. The lead soil screening level (SSL) of 400 ppm represents the conservative estimate by the EPA as a level of contamination considered a public health issue. The EPA recommends the removal of the lead contaminated soil if levels exceed the lead SSL.
RESULTS: The results obtained in this study will be utilized to understand lead’s propagation into plants from lead contaminated soil. Sample processing is still under way. Data will be compared to preliminary lead contamination testing performed by the EPA, which showed a range of soil lead levels from 348 to 654 ppm in the areas where the resident planted their produce.
CONCLUSION: Food scarcity relative to the COVID-19 pandemic and the following inflation on produce has led many to start home or community gardens. Increasing awareness on the risks of planting in areas without heavy metal evaluation is paramount for the future of those wishing to grow produce safely in their own backyard
Nitrogen dynamics in the Irish Sea and adjacent shelf waters: An exploration of dissolved organic nitrogen
AbstractRelatively little is known about dissolved organic nitrogen (DON) in the marine environment because research has historically focused on dissolved inorganic nitrogen (DIN). In this study we combine measurements of dissolved organic matter (DOM), DIN, particulate organic nitrogen (PON), dissolved inorganic phosphorus (DIP) and silicon (DIS), with temperature and salinity data from the western shelf region of the UK and Ireland, and with inorganic and organic nitrogen (N) data from the western Irish Sea to develop an understanding of N dynamics in the Irish Sea and adjacent shelf waters, and investigate the role of DON in the nitrogen budget of the seasonally stratifying western Irish Sea. In January 2013, the sampling area was divided by density fronts into 4 regions of distinct oceanography and homogeneous chemistry. DON concentrations accounted for 25.3 ± 1.8% of total dissolved N (TDN) across all regions. DOM concentrations generally decreased from the freshwater influenced water of Liverpool Bay to the oceanic waters of the Celtic Sea and Malin Shelf. Urea and dissolved free amino acids (DFAA) together made up 27.3 ± 3.1% of DON. Estimated concentrations in the rivers discharging into Liverpool Bay were 8.0 and 2.1 μmol N L−1 respectively: at the high end of reported riverine concentrations. Oceanic nutrient inputs to the Irish Sea only have a small influence on N concentrations. Riverine N inputs to the Irish Sea are substantial but are likely removed by natural N cycling processes. In the western Irish Sea, DON and PON concentrations reached maxima and minima in midsummer and early spring respectively. DIN followed the opposite trend. DON accounted for 38% of the yearly internal N cycling and we estimated that as much as 1.4 ± 1.2 μmol N L−1 of labile DON was available as an N source at the start of the spring bloom. Our study supports the view that DON plays an important role in N cycling in temperate shelf and coastal seas and should be included more often in biogeochemical measurements if we are to have a complete understanding of N dynamics in a changing world
Effects of bovine parathyroid hormone and 1,25-dihydroxyvitamin D3 on the production of prostaglandins by cells derived from human bone
AbstractLocal production of prostaglandins by osteoblasts may be important in controlling the bone resorbing activity of some hormones which have receptors on osteoblasts. We have demonstrated that osteoblast-like cells derived from human bone can incorporate [14C]arachidonic acid into phospholipids and synthesise immunoreactive PGE. Parathyroid hormone increases both the release of incorporated arachidonic acid and the synthesis of PGE. This is the first demonstration of modulation of bone cell prostaglandin synthesis by a bone resorbing hormone
Rift Valley Fever Virus Infection in Golden Syrian Hamsters
Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies
Treatment of Late Stage Disease in a Model of Arenaviral Hemorrhagic Fever: T-705 Efficacy and Reduced Toxicity Suggests an Alternative to Ribavirin
A growing number of arenaviruses are known to cause viral hemorrhagic fever (HF), a severe and life-threatening syndrome characterized by fever, malaise, and increased vascular permeability. Ribavirin, the only licensed antiviral indicated for the treatment of certain arenaviral HFs, has had mixed success and significant toxicity. Since severe arenaviral infections initially do not present with distinguishing symptoms and are difficult to clinically diagnose at early stages, it is of utmost importance to identify antiviral therapies effective at later stages of infection. We have previously reported that T-705, a substituted pyrazine derivative currently under development as an anti-influenza drug, is highly active in hamsters infected with Pichinde virus when the drug is administered orally early during the course of infection. Here we demonstrate that T-705 offers significant protection against this lethal arenaviral infection in hamsters when treatment is begun after the animals are ill and the day before the animals begin to succumb to disease. Importantly, this coincides with the time when peak viral loads are present in most organs and considerable tissue damage is evident. We also show that T-705 is as effective as, and less toxic than, ribavirin, as infected T-705-treated hamsters on average maintain their weight better and recover more rapidly than animals treated with ribavirin. Further, there was no added benefit to combination therapy with T-705 and ribavirin. Finally, pharmacokinetic data indicate that plasma T-705 levels following oral administration are markedly reduced during the latter stages of disease, and may contribute to the reduced efficacy seen when treatment is withheld until day 7 of infection. Our findings support further pre-clinical development of T-705 for the treatment of severe arenaviral infections
MP-12 virus containing the clone 13 deletion in the NSs gene prevents lethal disease when administered after Rift Valley fever virus infection in hamsters
Use of Recombinant Adenovirus Vectored Consensus IFN-α to Avert Severe Arenavirus Infection
Several arenaviruses can cause viral hemorrhagic fever, a severe disease with case-fatality rates in hospitalized individuals ranging from 15-30%. Because of limited prophylaxis and treatment options, new medical countermeasures are needed for these viruses classified by the National Institutes of Allergy and Infectious Diseases (NIAID) as top priority biodefense Category A pathogens. Recombinant consensus interferon alpha (cIFN-α) is a licensed protein with broad clinical appeal. However, while cIFN-α has great therapeutic value, its utility for biodefense applications is hindered by its short in vivo half-life, mode and frequency of administration, and costly production. To address these limitations, we describe the use of DEF201, a replication-deficient adenovirus vector that drives the expression of cIFN-α, for pre- and post-exposure prophylaxis of acute arenaviral infection modeled in hamsters. Intranasal administration of DEF201 24 h prior to challenge with Pichindé virus (PICV) was highly effective at protecting animals from mortality and preventing viral replication and liver-associated disease. A significant protective effect was still observed with a single dosing of DEF201 given two weeks prior to PICV challenge. DEF201 was also efficacious when administered as a treatment 24 to 48 h post-virus exposure. The protective effect of DEF201 was largely attributed to the expression of cIFN-α, as dosing with a control empty vector adenovirus did not protect hamsters from lethal PICV challenge. Effective countermeasures that are highly stable, easily administered, and elicit long lasting protective immunity are much needed for arena and other viral infections. The DEF201 technology has the potential to address all of these issues and may serve as a broad-spectrum antiviral to enhance host defense against a number of viral pathogens
The broad-spectrum antiviral favipiravir protects guinea pigs from lethal Lassa virus infection post-disease onset
With up to 500,000 infections annually, Lassa virus (LASV), the cause of Lassa fever, is one of the most prevalent etiological agents of viral hemorrhagic fever (VHF) in humans. LASV is endemic in several West African countries with sporadic cases and prolonged outbreaks observed most commonly in Sierra Leone, Liberia, Guinea and Nigeria. Additionally several cases of Lassa fever have been imported into North America, Europe and Asia making LASV a global threat to public health. Despite this, currently no approved therapeutic or vaccine exists to treat or prevent LASV infections. Here, using a passaged strain of LASV that is uniformly lethal in Hartley guinea pigs, we demonstrate that favipiravir, a broad-spectrum antiviral agent and leading treatment option for influenza, has potent activity against LASV infection. In this model, once daily treatment with favipiravir significantly reduced viral titers in tissue samples and reduced mortality rates when compared with animals receiving vehicle-only or ribavirin, the current standard of care for Lassa fever. Favipiravir remained highly effective against lethal LASV infection when treatments were initiated nine days post-infection, a time when animals were demonstrating advanced signs of disease. These results support the further preclinical evaluation of favipiravir for Lassa fever and other VHFs
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