Government investment and fiscal stimulus Leeper, Eric M.; Walker, Todd B.; Yang, Shu-Chun S.
Journal of monetary economics,
11/2010, Letnik:
57, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Effects of government investment are studied in an estimated neoclassical growth model. The analysis focuses on two dimensions that are critical for understanding government investment as a fiscal ...stimulus: implementation delays for building public capital and expected fiscal adjustments to deficit-financed spending. Implementation delays can produce small or even negative labor and output responses to increases in government investment in the short run. Anticipated fiscal adjustments matter both quantitatively and qualitatively for long-run growth effects. When public capital is insufficiently productive, distorting financing can make government investment contractionary at longer horizons.
► Implementation delays associated with government infrastructure spending can hinder the beneficial effects of that spending in the short run. ► Expected fiscal financing of government infrastructure spending can hinder the beneficial effects of that spending in the long run. ► Implementation delays associated with government infrastructure spending can reduce private investment more and raise labor and output less (or even lower them) in the short run, compared to the case without delays. ► Distorting fiscal financing of government investment dampens the growth effects of that investment in the long run.
We report direction detection constraints on the presence of hidden photon dark matter with masses between 20-30 μeV c^{-2}, using a cryogenic emitter-receiver-amplifier spectroscopy setup designed ...as the first iteration of QUALIPHIDE (quantum limited photons in the dark experiment). A metallic dish sources conversion photons, from hidden photon kinetic mixing, onto a horn antenna which is coupled to a C band kinetic inductance traveling wave parametric amplifier, providing for near quantum-limited noise performance. We demonstrate a first probing of the kinetic mixing parameter χ to the 10^{-12} level for the majority of hidden photon masses in this region. These results not only represent stringent constraints on new dark matter parameter space, but are also the first demonstrated use of wideband quantum-limited amplification for astroparticle applications.
Economists often postulate that fiscal expansions are less stimulative when government debt is high than when it is low. Empirical evidence, however, is ambiguous. Using a nonlinear neoclassical ...growth model, we show that the difference in government spending effects between high- and low-debt environments depends on the wealth effect on labor supply and on whether the government uses taxes or spending to retire debt. Because of interrelated state variables, structural VAR estimations conditioning on debt alone can fail to isolate debt-dependent effects. Also, uncertainty on when the government will conduct fiscal consolidations generates wide confidence bands for spending multipliers, further complicating efforts to estimate debt-dependent government spending effects.
Phytoremediation is an in situ, cost-effective potential strategy for cleanup of sites contaminated with trace metals. Selection of plant materials is an important factor for successful field ...phytoremediation. A field experiment was carried out to evaluate the phytoextraction abilities of six high biomass plants (Vertiveria zizanioides, Dianthus chinensis, Rumex K-1 (Rumex upatientia x R. timschmicus), Rumex crispus, and two populations of Rumex acetosa) in comparison to metal hyperaccumulators (Viola baoshanensis, Sedum alfredii). The paddy fields used in the experiment were contaminated with Pb, Zn, and Cd. Our results indicated that V. baoshanensis accumulated 28 mg kg-¹ Cd and S. alfredii accumulated 6,279 mg kg-¹ Zn (dry weight) in shoots, with bioconcentration factors up to 4.8 and 6.3, respectively. The resulting total extractions of V. baoshanensis and S. alfredii were 0.17 kg ha-¹ for Cd and 32.7 kg ha-¹ for Zn, respectively, with one harvest without any treatment. The phytoextraction rates of V. baoshanensis and S. alfredii for Cd and Zn were 0.88 and 1.15%, respectively. Among the high biomass plants, R. crispus extracted Zn and Cd of 26.8 and 0.16 kg ha-¹, respectively, with one harvest without any treatment, so it could be a candidate species for phytoextraction of Cd and Zn from soil. No plants were proved to have the ability to phytoextract Pb with high efficiency.
Background & Aims
How adiposity influences the effect of genetic variants on non‐alcoholic fatty liver disease (NAFLD) in the Asian population remains unclear. We aimed to study the association ...between genetic risk variants and susceptibility/severity of NAFLD in the lean, overweight and obese individuals.
Methods
Nine hundred and four community subjects underwent proton‐magnetic resonance spectroscopy and transient elastography examination. Lean (<23 kg/m2), overweight (23‐24.9 kg/m2) and obesity (≥25 kg/m2) were defined according to the body mass index cut‐offs for Asians. NAFLD was defined as intrahepatic triglycerides ≥5%. PNPLA3, TM6SF2, MBOAT7 and 9 other gene polymorphisms were analysed by rhAMPTM SNP assays.
Results
Five hundred and twenty‐nine (58.5%), 162 (17.9%) and 213 (23.6%) subjects were lean, overweight and obese, respectively. The prevalence of NAFLD was 12.4%, 41.4% and 59.1% in the three groups (P < .001). Amongst those with NAFLD, lean subjects (30.3%) were more likely to carry the PNPLA3 rs738409 GG genotype than overweight (17.9%) and obese subjects (17.4%) (P = .003). Compared with the CC genotype, the GG genotype was associated with the greatest increase in the risk of NAFLD in lean subjects (odds ratio OR 6.04), compared with overweight (OR 3.43, 95% CI 1.06, 11.14) and obese subjects (OR 2.51, 95% CI 0.93, 6.78). Additionally, the TM6SF2 rs58542926 TT genotype was associated with reduced serum triglycerides only in lean subjects. A gene‐BMI effect was not observed for the other gene polymorphisms.
Conclusions
The PNPLA3 rs738409 gene polymorphism has a greater effect on liver fat in Asian lean individuals than in overweight or obese ones.
The wide range of factors associated with the induction of autism is invariably linked with either inflammation or oxidative stress, and sometimes both. The use of acetaminophen in babies and young ...children may be much more strongly associated with autism than its use during pregnancy, perhaps because of well-known deficiencies in the metabolic breakdown of pharmaceuticals during early development. Thus, one explanation for the increased prevalence of autism is that increased exposure to acetaminophen, exacerbated by inflammation and oxidative stress, is neurotoxic in babies and small children. This view mandates extreme urgency in probing the long-term effects of acetaminophen use in babies and the possibility that many cases of infantile autism may actually be induced by acetaminophen exposure shortly after birth.
Background and purpose:
Recombinant cyclooxygenase‐2 (COX‐2) oxygenates 2‐arachidonoylglycerol (2‐AG)
in vitro
. We examined whether prostaglandin E
2
glycerol ester (PGE
2
‐G), a COX‐2 metabolite of ...2‐AG, occurs endogenously and affects nociception and immune responses.
Experimental approach:
Using mass spectrometric techniques, we examined whether PGE
2
‐G occurs
in vivo
and if its levels are altered by inhibition of COX‐2, monoacylglycerol (MAG) lipase or inflammation induced by carrageenan. We also examined the effects of PGE
2
‐G on nociception in rats and NFκB activity in RAW264.7 cells.
Key results:
PGE
2
‐G occurs endogenously in rat. Its levels were decreased by inhibition of COX‐2 and MAG lipase but were unaffected by carrageenan. Intraplantar administration of PGE
2
‐G induced mechanical allodynia and thermal hyperalgesia. In RAW264.7 cells, PGE
2
‐G and PGE
2
produced similar, dose‐related changes in NFκB activity. PGE
2
‐G was quickly metabolized into PGE
2
. While the effects of PGE
2
on thermal hyperalgesia and NFκB activity were completely blocked by a cocktail of antagonists for prostanoid receptors, the same cocktail of antagonists only partially antagonized the actions of PGE
2
‐G.
Conclusions and implications:
Thermal hyperalgesia and immunomodulation induced by PGE
2
‐G were only partially mediated by PGE
2
, which is formed by metabolism of PGE
2
‐G. PGE
2
‐G may function through a unique receptor previously postulated to mediate its effects. Taken together, these findings demonstrate that 2‐AG is oxygenated
in vivo
by COX‐2 producing PGE
2
‐G, which plays a role in pain and immunomodulation. COX‐2 could act as an enzymatic switch by converting 2‐AG from an antinociceptive mediator to a pro‐nociceptive prostanoid.
British Journal of Pharmacology
(2008)
153
, 1538–1549; doi:
10.1038/bjp.2008.33
; published online 25 February 2008
The human vermiform (“worm-like”) appendix is a 5–10
cm long and 0.5–1
cm wide pouch that extends from the cecum of the large bowel. The architecture of the human appendix is unique among mammals, ...and few mammals other than humans have an appendix at all. The function of the human appendix has long been a matter of debate, with the structure often considered to be a vestige of evolutionary development despite evidence to the contrary based on comparative primate anatomy. The appendix is thought to have some immune function based on its association with substantial lymphatic tissue, although the specific nature of that putative function is unknown. Based (a) on a recently acquired understanding of immune-mediated biofilm formation by commensal bacteria in the mammalian gut, (b) on biofilm distribution in the large bowel, (c) the association of lymphoid tissue with the appendix, (d) the potential for biofilms to protect and support colonization by commensal bacteria, and (e) on the architecture of the human bowel, we propose that the human appendix is well suited as a “safe house” for commensal bacteria, providing support for bacterial growth and potentially facilitating re-inoculation of the colon in the event that the contents of the intestinal tract are purged following exposure to a pathogen.
Background Gastroesophageal reflux disease (GERD) in lung recipients is associated with decreased survival and attenuated allograft function. This study evaluates fundoplication in preventing ...GERD-related allograft dysfunction. Methods Prospectively collected data on patients who underwent transplantation between January 2001 and August 2009 were included. Lung transplant candidates underwent esophageal pH probe testing before transplantation and surveillance spirometry evaluation after transplantation. Bilateral lung transplant recipients who had pretransplant pH probe testing and posttransplant 1-year forced expiratory volume in the first second of expiration (FEV1) data were included for analysis. Results Of 297 patients who met study criteria, 222 (75%) had an abnormal pH probe study before or early after transplantation and 157 (53%) had a fundoplication performed within the first year after transplantation. Patients with total proximal acid contact times greater than 1.2% or total distal acid contact times greater than 7.0% demonstrated an absolute decrease of 9.4% (± 4.6) or 12.0% (± 5.4) in their respective mean 1-year FEV1 values. Patients with abnormal acid contact times who did not undergo fundoplication had considerably worse predicted peak and 1-year FEV1 results compared with recipients receiving fundoplication (peak percent predicted = 75% vs. 84%; p = 0.004 and 1-year percent predicted = 68% vs. 77%; p = 0.003, respectively). Conclusions Lung transplant recipients with abnormal esophageal pH studies attain a lower peak allograft function as well as a diminished 1-year FEV1 after transplantation. However a strategy of early fundoplication in these recipients appears to preserve lung allograft function.
As the technology in automation and computation advances, traffic data can be easily collected from multiple sources, such as sensors and surveillance cameras. To extract value from the huge volumes ...of available data requires the capability to process and extract patterns in large datasets. In this paper, a machine learning method embedded within a big data analytics platform is constructed by using random forests method and Apache Hadoop to predict highway travel time based on data collected from highway electronic toll collection in Taiwan. Various prediction models are then developed for highway travel time based on historical and real-time data to provide drivers with estimated and adjusted travel time information.
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