524 research outputs found
The Forward Exchange Rate Bias Puzzle: Evidence from New Cointegration Tests
An important puzzle in international finance is the failure of the forward exchange rate to be a rational forecast of the future spot rate. It has often been suggested that this puzzle may be resolved by using better statistical procedures that correct for both non-stationarity and nonnormality in the data. We document that even after accounting for non-stationarity, nonnormality, and heteroscedasticity using parametric and non-parametric tests on data for over a quarter century, US dollar forward rates for horizons ranging from one to twelve months for the major currencies, the British pound, Japanese yen, Swiss franc, and the German mark, are generally not rational forecasts of future spot rates. These findings of non-rationality in forward exchange rates for the major currencies continue to be puzzling especially as these foreign exchange markets are some of the most liquid asset markets with very low trading costs.flight-to-quality, contagion, multivariate GARCH
Predicting Energy Requirement for Cooling the Building Using Artificial Neural Network
This paper explores total cooling load during summers and total carbon emissions of a six storey building by using artificial neural network (ANN). Parameters used for the calculation were conduction losses, ventilation losses, solar heat gain and internal gain. The standard back-propagation learning algorithm has been used in the network. The energy performance in buildings is influenced by many factors, such as ambient weather conditions, building structure and characteristics, the operation of sub-level components like lighting and HVAC systems, occupancy and their behavior. This complex situation makes it very difficult to accurately implement the prediction of building energy consumption. The calculated cooling load was 0.87 million kW per year. ANN application showed that data was best fit for the regression coefficient of 0.9955 with best validation performance of 0.41231 in case of conduction losses. To meet out this energy demand various fuel options are presented along with their cost and carbon emission
Psychedelics for brain injury: A mini-review
Objective: Stroke and traumatic brain injury (TBI) are among the leading causes of disability. Even after engaging in rehabilitation, nearly half of patients with severe TBI requiring hospitalization are left with major disability. Despite decades of investigation, pharmacologic treatment of brain injury is still a field in its infancy. Recent clinical trials have begun into the use of psychedelic therapeutics for treatment of brain injury. This brief review aims to summarize the current state of the science's relevance to neurorehabilitation, and may act as a resource for those seeking to understand the precedence for these ongoing clinical trials.Methods: Narrative mini-review of studies published related to psychedelic therapeutics and brain injury.Results: Recent in vitro, in vivo, and case report studies suggest psychedelic pharmacotherapies may influence the future of brain injury treatment through modulation of neuroinflammation, hippocampal neurogenesis, neuroplasticity, and brain complexity.Conclusions: Historical data on the safety of some of these substances could serve in effect as phase 0 and phase I studies. Further phase II trials will illuminate how these drugs may treat brain injury, particularly TBI and reperfusion injury from stroke
Psychoactive substances and the political ecology of mental distress
The goal of this paper is to both understand and depathologize clinically significant mental distress related to criminalized contact with psychoactive biotic substances by employing a framework known as critical political ecology of health and disease from the subdiscipline of medical geography. The political ecology of disease framework joins disease ecology with the power-calculus of political economy and calls for situating health-related phenomena in their broad social and economic context, demonstrating how large-scale global processes are at work at the local level, and giving due attention to historical analysis in understanding the relevant human-environment relations. Critical approaches to the political ecology of health and disease have the potential to incorporate ever-broadening social, political, economic, and cultural factors to challenge traditional causes, definitions, and sociomedical understandings of disease. Inspired by the patient-centered medical diagnosis critiques in medical geography, this paper will use a critical political ecology of disease approach to challenge certain prevailing sociomedical interpretations of disease, or more specifically, mental disorder, found in the field of substance abuse diagnostics and the related American punitive public policy regimes of substance abuse prevention and control, with regards to the use of biotic substances. It will do this by first critically interrogating the concept of "substances" and grounding them in an ecological context, reviewing the history of both the development of modern substance control laws and modern substance abuse diagnostics, and understanding the biogeographic dimensions of such approaches. It closes with proposing a non-criminalizing public health approach for regulating human close contact with psychoactive substances using the example of cannabis use
ECMO: a lifesaving modality in ARDS during puerperium
Acute respiratory distress syndrome (ARDS) is an uncommon condition encountered in pregnancy. The incidence of ARDS in pregnancy has been reported to be 1 in 6229 deliveries with mortality rates to range from 24% to 39% in pregnant patients. An essential component in management of ARDS involves good communication between the obstetrics team and critical care specialist and a fundamental understanding of mechanical ventilatory support. In critically ill patients where both cardiorespiratory support is required, Extracorporeal Membrane Oxygenation (ECMO) can be used to help maintain the vital functions. ECMO is a temporary cardio respiratory or respiratory support in critically ill patients who are unresponsive to conventional management. In present case a young female with post-partum ARDS was successfully managed with extra corporeal membrane oxygenation (ECMO)
Host Galaxy Properties and Offset Distributions of Fast Radio Bursts: Implications for their Progenitors
We present observations and detailed characterizations of five new host
galaxies of fast radio bursts (FRBs) discovered with the Australian Square
Kilometre Array Pathfinder (ASKAP) and localized to . Combining
these galaxies with FRB hosts from the literature, we introduce criteria based
on the probability of chance coincidence to define a sub-sample of 10
highly-confident associations (at ), three of which correspond to
known repeating FRBs. Overall, the FRB host galaxies exhibit a broad,
continuous range of color (), stellar mass (), and star-formation rate () spanning the full parameter space
occupied by galaxies. However, they do not track the color-magnitude,
SFR-, nor BPT diagrams of field galaxies surveyed at similar
redshifts. There is an excess of "green valley" galaxies and an excess of
emission-line ratios indicative of a harder radiation field than that generated
by star-formation alone. From the observed stellar mass distribution, we rule
out the hypothesis that FRBs strictly track stellar mass in galaxies (
c.l.). We measure a median offset of 3.3 kpc from the FRB to the estimated
center of the host galaxies and compare the host-burst offset distribution and
other properties with the distributions of long- and short-duration gamma-ray
bursts (LGRBs and SGRBs), core-collapse supernovae (CC-SNe), and Type Ia SNe.
This analysis rules out galaxies hosting LGRBs (faint, star-forming galaxies)
as common hosts for FRBs ( c.l.). Other transient channels (SGRBs, CC-
and Type Ia SNe) have host galaxy properties and offsets consistent with the
FRB distributions. All of the data and derived quantities are made publicly
available on a dedicated website and repository.Comment: Accepted for publication in ApJ. All data are publicly available at
https://frbhosts.org and https://github.com/FRBs/FRB. Version 2 of manuscript
includes updated FRB uncertainty estimate
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGOâs first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
A Study of Nuclear Transcription Factor-Kappa B in Childhood Autism
BACKGROUND: Several children with autism show regression in language and social development while maintaining normal motor milestones. A clear period of normal development followed by regression and subsequent improvement with treatment, suggests a multifactorial etiology. The role of inflammation in autism is now a major area of study. Viral and bacterial infections, hypoxia, or medication could affect both foetus and infant. These stressors could upregulate transcription factors like nuclear factor kappa B (NF-ÎșB), a master switch for many genes including some implicated in autism like tumor necrosis factor (TNF). On this hypothesis, it was proposed to determine NF-ÎșB in children with autism. METHODS: Peripheral blood samples of 67 children with autism and 29 control children were evaluated for NF-ÎșB using electrophoretic mobility shift assay (EMSA). A phosphor imaging technique was used to quantify values. The fold increase over the control sample was calculated and statistical analysis was carried out using SPSS 15. RESULTS: We have noted significant increase in NF-ÎșB DNA binding activity in peripheral blood samples of children with autism. When the fold increase of NF-ÎșB in cases (n = 67) was compared with that of controls (n = 29), there was a significant difference (3.14 vs. 1.40, respectively; p<0.02). CONCLUSION: This finding has immense value in understanding many of the known biochemical changes reported in autism. As NF-ÎșB is a response to stressors of several kinds and a master switch for many genes, autism may then arise at least in part from an NF-ÎșB pathway gone awry
Activation of adherent vascular neutrophils in the lung during acute endotoxemia
BACKGROUND: Neutrophils constitute the first line of defense against invading microorganisms. Whereas these cells readily undergo apoptosis under homeostatic conditions, their survival is prolonged during inflammatory reactions and they become biochemically and functionally activated. In the present study, we analyzed the effects of acute endotoxemia on the response of a unique subpopulation of neutrophils tightly adhered to the lung vasculature. METHODS: Rats were treated with 5 mg/kg lipopolysaccharide (i.v.) to induce acute endotoxemia. Adherent neutrophils were isolated from the lung vasculature by collagenase digestion and sequential filtering. Agarose gel electrophoresis, RT-PCR, western blotting and electrophoretic mobility shift assays were used to evaluate neutrophil activity. RESULTS: Adherent vascular neutrophils isolated from endotoxemic animals exhibited decreased apoptosis when compared to cells from control animals. This was associated with a marked increase in expression of the anti-apoptotic protein, Mcl-1. Cells isolated 0.5â2 hours after endotoxin administration were more chemotactic than cells from control animals and expressed increased tumor necrosis factor-alpha and cyclooxygenase-2 mRNA and protein, demonstrating that they are functionally activated. Endotoxin treatment of the animals also induced p38 and p44/42 mitogen activated protein kinases in the adherent lung neutrophils, as well as nuclear binding activity of the transcription factors, NF-ÎșB and cAMP response element binding protein. CONCLUSION: These data demonstrate that adherent vascular lung neutrophils are highly responsive to endotoxin and that pathways regulating apoptosis and cellular activation are upregulated in these cells
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