Disorder-free localisation in permutation symmetric fermionic quantum walks

We investigate the phenomenon of disorder-free localisation in a quantum system with a global permutation symmetry and the exchange symmetry for identical particles. We start with a systematic construction of many-fermion Hamiltonians with a global permutation symmetry using the conjugacy classes of the permutation group $S_N$, with $N$ being the total number of fermions. The resulting Hamiltonians are interpreted as generators of continuous-time quantum walk of indistinguishable fermions. In this setup we analytically solve the simplest example and show that for large $N$ all the states are localised without the introduction of any disorder coefficients. The localisation is also time-independent and is not the result of any emergent disorder. This seems to be an important distinction from other mechanisms of disorder-free localisation. Furthermore, we show that the localisation is stable to interactions that preserve the global $S_N$ symmetry making these systems potential candidates for a quantum memory. By marking sites and reducing the symmetry to subgroups of $S_N$, the localisation can be obtained for any $N$ by tuning the symmetry-reducing parameters in the Hamiltonian. Finally we show that similar localisation also occurs for spin systems governed by a $S_N$-symmetric Heisenberg chain and we make a few comments about $S_N$-symmetric bosonic systems. The models we propose feature all-to-all connectivity and can be realised on superconducting quantum circuits and trapped ion systems.Comment: 24 pages, 2 figures ; v2- 27 pages, 2 figures, slight modifications in the abstract and introductio

Global Health Teaching in India: A Curricular Landscape

Today, health has transcended national boundaries and become more multifaceted. Global health has evolved as a new paradigm and is recently being identified as a thrust area now in India. Despite an existing need for a standardized global health curriculum, there is little information available on its education and curriculum in medical and health education space. In the Indian context, we are yet to have a fuller picture of the current status, including, content, structure, selection, teaching methods of global health, and how students are evaluated in India. The objective of this study was to map courses relating to studies on global health in India and analyze its mode of delivery. A detailed Internet search was carried out to identify global health courses and analyzed for: (i) whether global health is a part of the teaching curriculum, (ii) mode of teaching, (iii) broad contents, (iv) instructional formats, (v) assessment, and (vi) selection process. It was found that delivery of global health education in India was fragmented with limited focus at the undergraduate and postgraduate levels. Global health teaching was largely based on certificate courses or online courses, with hardly any institutions imparting a distinct global health education program. There is also no definite specification as to which institutes can impart teaching on global health education and what the specific eligibility requirements are. Our analysis suggests that efforts should be directed toward integrating global health education into broader public health curriculum. At the same time, the need for generation of global health leaders, creation of a common forum for addressing merits and demerits of global health issues, as well as creation of more opportunities for placements are recognized

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

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

Ocular Langerhans Cell Histiocytosis (A Multisystem Involvement of Langerhans Cell Histiocytosis)

A 2 year old boy was referred from paediatrics OPD to Eye OPD with chief complaint of Multiple conjunctival cyst since 15 days. The patient had a prior history of recurrent chest infections. Requiring hospitalisation since 7 months of age. Upon visual acuity examination, the patient seemed to follow light.Fundus examination of both eyes were within normal limits.H&amp; E sections of the lesions showed collection of histiocytes typical of Langerhans Cell Histiocytosis.Patient was treated with multiple cycles of Vinblastine and predinisolone as per LCH 3 guidelines. Langerhans cell histiocytosis (LCH), the most common histiocytic disorder in children. LCH lesions are granulomatous lesions consisting of pathologic “Langerhans cells” (LCs), lymphocytes (primarily T-cells), eosinophils, and macrophages. The incidence of LCH is estimated to be around 5–10 cases per million children per year and 1–2 cases per million adults per year with a male is to female ratio 1.2:1.Its pathology is ‘Misguided Myeloid Differentiation’ where state of differentiation of myeloid precursor in which activating MAPK mutation arises determines the extent and severity of disease[1]. The current standard of care for initial therapy is vinblastine/prednisone for one year

Selector genes display tumor cooperation and inhibition in Drosophila epithelium in a developmental context-dependent manner

During animal development, selector genes determine identities of body segments and those of individual organs. Selector genes are also misexpressed in cancers, although their contributions to tumor progression per se remain poorly understood. Using a model of cooperative tumorigenesis, we show that gain of selector genes results in tumor cooperation, but in only select developmental domains of the wing, haltere and eye-antennal imaginal discs of Drosophila larva. Thus, the field selector, Eyeless (Ey), and the segment selector, Ultrabithorax (Ubx), readily cooperate to bring about neoplastic transformation of cells displaying somatic loss of the tumor suppressor, Lgl, but in only those developmental domains that express the homeo-box protein, Homothorax (Hth), and/or the Zinc-finger protein, Teashirt (Tsh). In non-Hth/Tsh-expressing domains of these imaginal discs, however, gain of Ey in lgl− somatic clones induces neoplastic transformation in the distal wing disc and haltere, but not in the eye imaginal disc. Likewise, gain of Ubx in lgl− somatic clones induces transformation in the eye imaginal disc but not in its endogenous domain, namely, the haltere imaginal disc. Our results reveal that selector genes could behave as tumor drivers or inhibitors depending on the tissue contexts of their gains