315 research outputs found
Predicting utility under satiation and habituation
We introduce a modification of the discounted utility model that accounts for both habituation and satiation in intertemporal choice. Habituation level and satiation level are state variables that induce changes in preferences as those states vary. We examine several properties of our model, discuss willingness to pay for an additional unit of consumption, and characterize the optimal consumption path. Predicted utility under projection bias and narrow bracketing is compared to actual realized utility. We argue that projection bias and narrow bracketing successfully explain the hedonic treadmill in the research area of happiness and life satisfaction.Time preference; discounted utility; habituation; satiation; local substitution; well-being; life satisfaction;
Does more money buy you more happiness?
Why do we believe that more money will buy us more happiness (when in fact it does not)? In this paper, we propose a model to explain this puzzle. The model incorporates both adaptation and social comparison. A rational person who fully accounts for the dynamics of these factors would indeed buy more happiness with money. We argue that projection bias, that is, the tendency to project into the future our current reference levels, precludes subjects from correctly calculating the utility obtained from consumption. Projection bias has two effects. First, it makes people overrate the happiness that they will obtain from money. Second, it makes people misallocate the consumption budget by consuming too much at the beginning of the planning horizon, or consuming too much of adaptive goods.Happiness; Life Satisfaction; Social Comparison; Consumer Life-Cycle Planning; Projection Bias;
Happiness and time allocation
We consider a resource allocation problem in which time is the principal resource. Utility is derived from time-consuming leisure activities, as well as from consumption. To acquire consumption, time needs to be allocated to income generating activities (i.e., work). Leisure (e.g., social relationships, family and rest) is considered a basic good, and its utility is evaluated using the Discounted Utility Model. Consumption is adaptive and its utility is evaluated using a reference-dependent model. Key empirical findings in the happiness literature can be explained by our time allocation model. Further, we examine the impact of projection bias on time allocation between work and leisure. Projection bias causes individuals to overrate the utility derived from income; consequently, individuals may allocate more than the optimal time to work. This misallocation may produce a scenario in which a higher wage rate results in a lower total utility.Life satisfaction; Work; Leisure; Social comparison; Adaptation;
Fire Debris Analysis: A Need to Develop Databases
Fire debris analysis is a branch of forensic chemistry
which deals with the examination and analysis of fire debris
samples in order to detect and identify ignitable liquid
residues in them. In addition to arson, fire debris analysis is
usually performed in cases of fires of suspicious origin [1].
In addition to this, petrol bombs are used in social or religious
riots, and terrorist activities. In a developing country
like India, “bride burning” for dowry presents another aspect
of such crimes and includes cases of homicidal or suicidal
burning which require such examination [2]. Fire debris
analysis is performed to determine the presence or absence
of ignitable liquids in samples, to identify the chemical composition
of ignitable liquid, the class of ignitable liquid, and
to establish an association between ignitable liquid residues
and its source
Minimal hepatic encephalopathy: consensus statement of a working party of the Indian National Association for study of the liver
Hepatic encephalopathy (HE) is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Overt HE occurs in approximately 30-45% of cirrhotic patients. Minimal HE (MHE), the mildest form of HE, is characterized by subtle motor and cognitive deficits and impairs health-related quality of life. The Indian National Association for Study of the Liver (INASL) set up a Working Party on MHE in 2008 with a mandate to develop consensus guidelines on various aspects of MHE relevant to clinical practice. Questions related to the definition of MHE, its prevalence, diagnosis, clinical characteristics, pathogenesis, natural history and treatment were addressed by the members of the Working Party
Normalization of tumour blood vessels improves the delivery of nanomedicines in a size-dependent manner
The blood vessels of cancerous tumours are leaky and poorly organized. This can increase the interstitial fluid pressure inside tumours and reduce blood supply to them, which impairs drug delivery. Anti-angiogenic therapies—which ‘normalize’ the abnormal blood vessels in tumours by making them less leaky—have been shown to improve the delivery and effectiveness of chemotherapeutics with low molecular weights, but it remains unclear whether normalizing tumour vessels can improve the delivery of nanomedicines. Here, we show that repairing the abnormal vessels in mammary tumours, by blocking vascular endothelial growth factor receptor-2, improves the delivery of smaller nanoparticles (diameter, 12 nm) while hindering the delivery of larger nanoparticles (diameter, 125 nm). Using a mathematical model, we show that reducing the sizes of pores in the walls of vessels through normalization decreases the interstitial fluid pressure in tumours, thus allowing small nanoparticles to enter them more rapidly. However, increased steric and hydrodynamic hindrances, also associated with smaller pores, make it more difficult for large nanoparticles to enter tumours. Our results further suggest that smaller (~12 nm) nanomedicines are ideal for cancer therapy due to their superior tumour penetration.ImClone Systems IncorporatedNational Institutes of Health (U.S.) (P01-CA080124)National Institutes of Health (U.S.) (R01-CA126642)National Institutes of Health (U.S.) (R01-CA115767)National Institutes of Health (U.S.) (R01-CA096915)National Institutes of Health (U.S.) (R01-CA085140)National Institutes of Health (U.S.) (R01-CA098706)National Institutes of Health (U.S.) (T32-CA073479)United States. Dept. of Defense (Breast Cancer Research Innovator Award W81XWH-10-1-0016
Reduced cortical thickness in patients with acute-on-chronic liver failure due to non-alcoholic etiology
Background:
Acute-on-chronic liver failure (ACLF) is a form of liver disease with high short-term mortality. ACLF offers considerable potential to affect the cortical areas by significant tissue injury due to loss of neurons and other supporting cells. We measured changes in cortical thickness and metabolites profile in ACLF patients following treatment, and compared it with those of age matched healthy volunteers.
Methods:
For the cortical thickness analysis we performed whole brain high resolution T1-weighted magnetic resonance imaging (MRI) on 15 ACLF and 10 healthy volunteers at 3T clinical MR scanner. Proton MR Spectroscopy (1H MRS) was also performed to measure level of altered metabolites. Out of 15 ACLF patients 10 survived and underwent
follow-up study after clinical recovery at 3 weeks. FreeSurfer program was used to quantify cortical thickness and LC- Model software was used to quantify absolute metabolites concentrations. Neuropsychological (NP) test was performed to assess the cognitive performance in follow-up ACLF patients compared to controls.
Results:
Significantly reduced cortical thicknesses in multiple brain sites, and significantly decreased N-acetyl
aspartate (NAA), myo-inositol (mI) and significantly increased glutamate/glutamine (glx) metabolites were observed in ACLF compared to those of controls at baseline study. Follow-up patients showed significant recovery in cortical thickness and Glx level, while NAA and mI were partially recovered compared to baseline study. When compared to controls, follow-up patients still showed reduced cortical thickness and altered metabolites level. Follow-up patients had abnormal neuropsychological (NP) scores compared to controls.
Conclusions:
Neuronal loss as suggested by the reduced NAA, decreased cellular density due to increased cerebral hyperammonemia as supported by the increased glx level, and increased proinflammatory cytokines and free radicals may account for the reduced cortical thickness in ACLF patients. Presence of reduced cortical thickness, altered
metabolites and abnormal NP test scores in post recovery subjects as compared to those of controls is associated
with incomplete clinical recovery. The current imaging protocol can be easily implemented in clinical settings to evaluate and monitor brain tissue changes in patients with ACLF during the course of treatment
All-sky search for long-duration gravitational-wave bursts in the third Advanced LIGO and Advanced Virgo run
After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” ≲1 s and “long” ≳1 s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use minimal assumptions for the sky location, event time, waveform morphology, and duration of the source. The search covers the range of 2–500 s in duration and a frequency band of 24–2048 Hz. We find no significant triggers within this parameter space; we report sensitivity limits on the signal strength of gravitational waves characterized by the root-sum-square amplitude hrss as a function of waveform morphology. These hrss limits improve upon the results from the second observing run by an average factor of 1.8
The population of merging compact binaries inferred using gravitational waves through GWTC-3
We report on the population properties of 76 compact binary mergers detected with gravitational waves below a false alarm rate of 1 per year through GWTC-3. The catalog contains three classes of binary mergers: BBH, BNS, and NSBH mergers. We infer the BNS merger rate to be between 10 and 1700 and the NSBH merger rate to be between 7.8 and 140 , assuming a constant rate density versus comoving volume and taking the union of 90% credible intervals for methods used in this work. Accounting for the BBH merger rate to evolve with redshift, we find the BBH merger rate to be between 17.9 and 44 at a fiducial redshift (z=0.2). We obtain a broad neutron star mass distribution extending from to . We can confidently identify a rapid decrease in merger rate versus component mass between neutron star-like masses and black-hole-like masses, but there is no evidence that the merger rate increases again before 10 . We also find the BBH mass distribution has localized over- and under-densities relative to a power law distribution. While we continue to find the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above . The rate of BBH mergers is observed to increase with redshift at a rate proportional to with for . Observed black hole spins are small, with half of spin magnitudes below . We observe evidence of negative aligned spins in the population, and an increase in spin magnitude for systems with more unequal mass ratio
Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run
We present a search for dark photon dark matter that could couple to
gravitational-wave interferometers using data from Advanced LIGO and Virgo's
third observing run. To perform this analysis, we use two methods, one based on
cross-correlation of the strain channels in the two nearly aligned LIGO
detectors, and one that looks for excess power in the strain channels of the
LIGO and Virgo detectors. The excess power method optimizes the Fourier
Transform coherence time as a function of frequency, to account for the
expected signal width due to Doppler modulations. We do not find any evidence
of dark photon dark matter with a mass between eV/, which corresponds to frequencies between 10-2000
Hz, and therefore provide upper limits on the square of the minimum coupling of
dark photons to baryons, i.e. dark matter. For the
cross-correlation method, the best median constraint on the squared coupling is
at eV/; for the
other analysis, the best constraint is at eV/. These limits improve upon those obtained
in direct dark matter detection experiments by a factor of for
eV/, and are, in absolute terms, the
most stringent constraint so far in a large mass range eV/.Comment: 20 pages, 7 figure
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