2,013 research outputs found
Monetary Policy and Long-Term Real Rates
Abstract Changes in monetary policy have surprisingly strong effects on forward real rates in the distant future. A 100 basis-point increase in the 2-year nominal yield on an FOMC announcement day is associated with a 42 basis-point increase in the 10-year forward real rate. This finding is at odds with standard macro models based on sticky nominal prices, which imply that monetary policy cannot move real rates over a horizon longer than that over which all prices in the economy can readjust. Rather, the responsiveness of long-term real rates to monetary shocks appears to reflect changes in term premia. One mechanism that may generate such variation in term premia is based on demand effects coming from "yield-oriented" investors. We find some evidence supportive of this channel. * We thank John Campbell, Gene Fama, Emmanuel Farhi, Robin Greenwood, Anil Kashyap, David Scharfstein, Larry Summers, Adi Sunderam, Paul Tucker, Luis Viceira, and seminar participants at Harvard University for helpful comments. The analysis and conclusions set forth are those of the authors and do not indicate concurrence by other members of the Board of Governors.
1+1 dimensional QCD with fundamental bosons and fermions
We analyze the properties of mesons in 1+1 dimensional QCD with bosonic and
fermionic ``quarks'' in the large \nc limit. We study the spectrum in detail
and show that it is impossible to obtain massless mesons including boson
constituents in this model. We quantitatively show how the QCD mass inequality
is realized in two dimensional QCD. We find that the mass inequality is close
to being an equality even when the quarks are light. Methods for obtaining the
properties of ``mesons'' formed from boson and/or fermion constituents are
formulated in an explicit manner convenient for further study. We also analyze
how the physical properties of the mesons such as confinement and asymptotic
freedom are realized.Comment: 20 pages, harvmac, 5 figure
Spacetime Covariant Form of Ashtekar's Constraints
The Lagrangian formulation of classical field theories and in particular
general relativity leads to a coordinate-free, fully covariant analysis of
these constrained systems. This paper applies multisymplectic techniques to
obtain the analysis of Palatini and self-dual gravity theories as constrained
systems, which have been studied so far in the Hamiltonian formalism. The
constraint equations are derived while paying attention to boundary terms, and
the Hamiltonian constraint turns out to be linear in the multimomenta. The
equivalence with Ashtekar's formalism is also established. The whole constraint
analysis, however, remains covariant in that the multimomentum map is evaluated
on {\it any} spacelike hypersurface. This study is motivated by the
non-perturbative quantization program of general relativity.Comment: 22 pages, plain Tex, no figures, accepted for publication in Nuovo
Cimento
Gender Differences in Russian Colour Naming
In the present study we explored Russian colour naming in a web-based psycholinguistic experiment
(http://www.colournaming.com). Colour singletons representing the Munsell Color Solid (N=600 in total) were presented on a computer monitor and named using an unconstrained colour-naming method. Respondents were
Russian speakers (N=713). For gender-split equal-size samples (NF=333, NM=333) we estimated and compared (i)
location of centroids of 12 Russian basic colour terms (BCTs); (ii) the number of words in colour descriptors; (iii) occurrences of BCTs most frequent non-BCTs. We found a close correspondence between females’ and males’
BCT centroids. Among individual BCTs, the highest inter-gender agreement was for seryj ‘grey’ and goluboj
‘light blue’, while the lowest was for sinij ‘dark blue’ and krasnyj ‘red’. Females revealed a significantly richer repertory of distinct colour descriptors, with great variety of monolexemic non-BCTs and “fancy” colour names; in comparison, males offered relatively more BCTs or their compounds. Along with these measures, we gauged
denotata of most frequent CTs, reflected by linguistic segmentation of colour space, by employing a synthetic
observer trained by gender-specific responses. This psycholinguistic representation revealed females’ more
refined linguistic segmentation, compared to males, with higher linguistic density predominantly along the redgreen axis of colour space
Perinatal autopsy in Ghana: Healthcare workers knowledge and attitude
BackgroundPerinatal mortality refers to stillbirths and early neonatal deaths. Stillbirth, the death of a foetus from 28 weeks or with a birth weight below 1,000 g, and early neonatal deaths, the death of a new-born within 24 h of delivery, are among the most distressing global health problems, with approximately 2 million stillbirths occurring annually. Although a post-mortem examination of the stillborn baby is essential for understanding and learning the cause of stillbirth, many couples decline the procedure. Sub-Saharan Africa has one of the highest stillbirth rates in the world, yet there is a dearth of studies on post-mortem uptake from the region.AimTo explore healthcare professionals' views and perceptions of perinatal autopsy in Ghana.MethodsMixed-method approach consisted of semi-structured interviews and an electronic cross-sectional survey to evaluate the views and perceptions of healthcare professionals at Korle-Bu Teaching Hospital on autopsy for stillbirths and early neonatal deaths. Descriptive quantitative data were summarised in frequencies and percentages, and statistical results and descriptions were tabulated and coded in terms of types of barriers. For the qualitative aspect, the audio-taped interviews were transcribed, themes generated, and direct quotes and descriptions were coded for all knowledge, beliefs, attitudes and practices concerning the barriers and facilitators for post-mortem.ResultsNinety-nine healthcare professionals participated. No participant had formal training regarding counselling for perinatal autopsy and 40% had “no idea” who is responsible for counselling and obtaining consent for a perinatal autopsy. Forty-four percent (44%) of the participants knew of only the “Conventional/ Full” autopsy and <4% were aware of less invasive methods of performing an autopsy. Qualitative data showed healthcare worker influence, religious and financial considerations impede the implementation of perinatal autopsies. Despite the low uptake of perinatal autopsies, interviews from healthcare workers suggest acceptance rates would improve if parents knew about different options, especially less invasive procedures.ConclusionAt Ghana's largest referral centre, perinatal autopsy counselling and uptake are at extremely low levels. Most healthcare professionals have little knowledge, skills, and capacity to advise parents regarding perinatal autopsies. Training is needed to update the workforce on recommended perinatal autopsy practices
Availability and price of malaria rapid diagnostic tests in the public and private health sectors in 2011: results from 10 nationally representative cross-sectional retail surveys.
OBJECTIVES: To describe the state of the public and private malaria diagnostics market shortly after WHO updated its guidelines for testing all suspected malaria cases prior to treatment. METHODS: Ten nationally representative cross-sectional cluster surveys were conducted in 2011 among public and private health facilities, community health workers and retail outlets (pharmacies and drug shops) in nine countries (Tanzania mainland and Zanzibar surveyed separately). Eligible outlets had antimalarials in stock on the day of interview or had stocked antimalarials in the past 3 months. RESULTS: Three thousand four hundred and thirty-nine rapid diagnostic test (RDT) products from 39 manufacturers were audited among 12,197 outlets interviewed. Availability was typically highest in public health facilities, although availability in these facilities varied greatly across countries, from 15% in Nigeria to >90% in Madagascar and Cambodia. Private for-profit sector availability was 46% in Cambodia, 20% in Zambia, but low in other countries. Median retail prices for RDTs in the private for-profit sector ranged from 3.13 in Zambia. The reported number of RDTs used in the 7 days before the survey in public health facilities ranged from 3 (Benin) to 50 (Zambia). CONCLUSIONS: Eighteen months after WHO updated its case management guidelines, RDT availability remained poor in the private sector in sub-Saharan Africa. Given the ongoing importance of the private sector as a source of fever treatment, the goal of universal diagnosis will not be achievable under current circumstances. These results constitute national baselines against which progress in scaling-up diagnostic tests can be assessed
IFNβ Protects Neurons from Damage in a Murine Model of HIV-1 Associated Brain Injury.
Infection with human immunodeficiency virus-1 (HIV-1) causes brain injury. Type I interferons (IFNα/β) are critical mediators of any anti-viral immune response and IFNβ has been implicated in the temporary control of lentiviral infection in the brain. Here we show that transgenic mice expressing HIV-1 envelope glycoprotein 120 in their central nervous system (HIVgp120tg) mount a transient IFNβ response and provide evidence that IFNβ confers neuronal protection against HIVgp120 toxicity. In cerebrocortical cell cultures, neuroprotection by IFNβ against gp120 toxicity is dependent on IFNα receptor 1 (IFNAR1) and the β-chemokine CCL4, as IFNAR1 deficiency and neutralizing antibodies against CCL4, respectively, abolish the neuroprotective effects. We find in vivo that IFNβ mRNA is significantly increased in HIVgp120tg brains at 1.5, but not 3 or 6 months of age. However, a four-week intranasal IFNβ treatment of HIVgp120tg mice starting at 3.5 months of age increases expression of CCL4 and concomitantly protects neuronal dendrites and pre-synaptic terminals in cortex and hippocampus from gp120-induced damage. Moreover, in vivo and in vitro data suggests astrocytes are a major source of IFNβ-induced CCL4. Altogether, our results suggest exogenous IFNβ as a neuroprotective factor that has potential to ameliorate in vivo HIVgp120-induced brain injury
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