44 research outputs found
Entropy function from the Einstein boundary term
We show using the entropy function formalism developed by Sen
\cite{Sen:2005wa} that the boundary term which arises from the Einstein-Hilbert
action is sufficient to yield the Bekenstein-Hawking entropy of a static
extremal black hole which is asymptotically flat. However, for asymptotically
black holes, the bulk term also plays an important role due to the
presence of the cosmological constant. Further, we show that for extremal
rotating black holes, both the boundary and the bulk terms contribute
non-vanishing pieces to the entropy.Comment: v1: 9 pages LaTex, v2: 10 pages LaTex (to appear in Europhysics
Letters
The role of mutual information in the Page curve
In this work, we give two proposals regarding the status of connectivity of
entanglement wedges and the associated saturation of mutual information. The
first proposal has been given for the scenario before the Page time depicting
the fact that at a particular value of the observer's time (where
), the mutual information vanishes representing the
disconnected phase of the radiation entanglement wedge. We argue that this time
is the Hartman-Maldacena time at which the fine-grained entropy of radiation
goes as , where is the inverse of Hawking
temperature of the black hole. On the other hand, the second proposal probes
the crucial role played by the mutual information of black hole subsystems in
obtaining the correct Page curve of radiation.Comment: v1: 7 pages LaTex, 2 figures, v2: 9 pages LaTex, 2 figures. Accepted
for publication in Physical Review
Mutual information of subsystems and the Page curve for Schwarzschild de-Sitter black hole
In this work, we show that the two proposals associated to the mutual
information of matter fields can be given for an eternal Schwarzschild black
hole in de-Sitter spacetime. These proposals also depicts the status of
associated entanglement wedges and their roleplay in obtaining the correct Page
curve of radiation. The first proposal has been give for the before Page time
scenario, which shows that the mutual information
vanishes at a certain value of the observer's time (where
). We claim that this is the Hartman-Maldacena time at
which the entanglement wedge associated to gets
disconnected and the fine-grained radiation entropy has the form . The second proposal depicts the fact that just after the Page
time, when the replica wormholes are the dominating saddle-points, the mutual
information vanishes as soon as the time difference
equals the scrambling time. Holographically, this
reflects that the entanglement wedge associated to
jumps to the disconnected phase at this particular time-scale. Furthermore,
these two proposals lead us to the correct time-evolution of the fine-grained
entropy of radiation as portrayed by the Page curve. We have also shown that
similar observations can be obtained for the radiation associated to the
cosmological horizon.Comment: v1:18 pages LaTex with multiple figures, v2: matches with the
accepted version; To appear in Physical Review
Mixed state information theoretic measures in boosted black brane
In this paper, we study various mixed state information theoretic quantities
for a boosted black brane geometry. We have considered two set ups, namely, the
subsystem taken parallel and perpendicular to the direction of the boost. The
quantities that we calculate are the entanglement wedge cross-section, mutual
information, entanglement negativity and mutual complexity. In particular, we
study the dependence of these quantities on the boost parameter. We then
proceed to calculate the asymmetry ratios of these quantities, and observe that
they are independent of the subsystem size. Finally, we proceed to study an
interesting limit of the boosted black brane geometry, which is the so called
AdS wave geometry. We once again compute all the mixed state information
theoretic quantities for this geometry.Comment: 32 pages LaTex and 9 figures, comments are welcom
Evaluation of an organic package of practice towards integrated management of Solanum tuberosum and its comparison with conventional farming in terms of yield, quality, energy efficiency and economics
A study was taken up during 2014-16 for evaluating the potential of an organic package of practice towards integrated crop production (green farming) in comparison to conventional farmers’ practice in West Bengal, India. Under green farming, compost was integrated with chemical fertilizer for soil management while organic plant/ pest management was undertaken utilizing Inhana Rational Farming (IRF) Technology. The study indicated higher yield (9.7 %), higher nutrient use efficiency and economic sustainability under green farming irrespective of study area or potato variety. Higher qualitative expression in terms of starch content, pulp pH, vitamin C etc. under green farming might be due to the organic plant management aimed at energization of plant biochemical functions. Soil quality development as noted under green farming might have been influenced by the on-farm produced compost containing rich self- generated micro flora (in order of 1016 per colony forming unit.). The study indicated that green farming may serve as an efficient substitute of conventional farming towards yield sustenance, abatement of food toxicity and quality end product; through higher use of renewable energy and activation of plant physiological functions
Evaluation of Different Organic ‘Packages of Practice’ in Young Tea Plantation: A case study under FAO-CFC-TBI Project at Maud Tea Estate, Assam, India
Maintenance of young tea under organic package of practice is a challenging task and needs a proper intervention. The present study under FAO-CFC-TBI project was done at Maud Tea Estate, Assam, India to find out an effective pathway for growing healthy and productive young tea plants. Seven different organic packages of practice were chosen to evaluate their potential in terms of crop efficiency as well as soil quality rejuvenation. Crop yield was recorded of highest value under Inhana Rational Farming (IRF-2: made tea 807 kgha-1) package of practice. Yield under the treatment was 55.2 percent higher than control and about 25.6 percent higher than the next best performing package of practice i.e. VMI (653 kgha-1). The third highest yield was obtained under IRF-1 and VCO, which recorded almost similar crop (made tea: 619 & 618 kgha-1 resp.) followed by BD (593 kgha-1), Co (567 kgha-1) and MI (556 kgha-1) packages. Value cost ratio (VCR), which is excess revenue generated per unit rupee invested; followed similar trend as observed in case of New Plantation experiment indicating highest economic sustainability under IRF-2 (4.37) followed by IRF-1 (2.33) package. Value cost ratio in case of other organic packages varied between 0.25 and 1.02, indicating economic vulnerability considering that VCR < 2.00 has been indicated by Agricultural economists as the critical mark below which there is no necessary risk coverage against investment towards input cost
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Activation of decapping involves binding of the mRNA and facilitation of the post-binding steps by the Lsm1-7–Pat1 complex
Decapping is a critical step in the conserved 5′-to-3′ mRNA decay pathway of eukaryotes. The hetero-octameric Lsm1-7–Pat1 complex is required for normal rates of decapping in this pathway. This complex also protects the mRNA 3′-ends from trimming in vivo. To elucidate the mechanism of decapping, we analyzed multiple lsm1 mutants, lsm1-6, lsm1-8, lsm1-9, and lsm1-14, all of which are defective in decapping and 3′-end protection but unaffected in Lsm1-7–Pat1 complex integrity. The RNA binding ability of the mutant complex was found to be almost completely lost in the lsm1-8 mutant but only partially impaired in the other mutants. Importantly, overproduction of the Lsm1-9p- or Lsm1-14p-containing (but not Lsm1-8p-containing) mutant complexes in wild-type cells led to a dominant inhibition of mRNA decay. Further, the mRNA 3′-end protection defect of lsm1-9 and lsm1-14 cells, but not the lsm1-8 cells, could be partly suppressed by overproduction of the corresponding mutant complexes in those cells. These results suggest the following: (1) Decapping requires both binding of the Lsm1-7–Pat1 complex to the mRNA and facilitation of the post-binding events, while binding per se is sufficient for 3′-end protection. (2) A major block exists at the post-binding steps in the lsm1-9 and lsm1-14 mutants and at the binding step in the lsm1-8 mutant. Consistent with these ideas, the lsm1-9, 14 allele generated by combining the mutations of lsm1-9 and lsm1-14 alleles had almost fully lost the RNA binding activity of the complex and behaved like the lsm1-8 mutant