Measurements of Natural Carbonate Rare Earth Elements in Femtogram Quantities by Inductive Coupled Plasma Sector Field Mass Spectrometry

A rapid and precise standard-bracketing method has been developed for measuring femtogram quantity rare earth element (REE) levels in natural carbonate samples by inductively coupled plasma sector field mass spectrometry that does not require chemical separation steps. A desolvation nebulization system was used to effectively reduce polyatomic interference and enhance sensitivity. REE/Ca ratios are calculated directly from the intensities of the ion beams of 46Ca, 139La, 140Ce, 141Pr, 146Nd, 147Sm, 153Eu, 160Gd, 159Tb, 163Dy, 165Ho, 166Er, 169Tm, 172Yb, and 175Lu using external matrix-matched synthetic standards to correct for instrumental ratio drifting and mass discrimination. A routine measurement time of 3 min is typical for one sample containing 20-40 ppm Ca. Replicate measurements made on natural coral and foraminiferal samples with REE/Ca ratios of 2-242 nmol/mol show that external precisions of 1.9-6.5% (2 RSD) can be achieved with only 10-1000 fg of REEs in 10-20 μg of carbonate. We show that different sources for monthly resolved coral ultratrace REE variability can be distinguished using this method. For natural slow growth-rate carbonate materials, such as sclerosponges, tufa, and speleothems, the high sample throughput, high precision, and high temporal resolution REE records that can be produced with this procedure have the potential to provide valuable time-series records to advance our understanding of paleoclimatic and paleoenvironmental dynamics on different time scales

A Case of Familial Comedonal Darier's Disease

Darier's disease is a genetic disorder of keratinization with autosomal dominant inheritance. Its appearance is usually in the form of greasy, crusted, keratotic yellow-brown papules and plaques found particularly on seborrheic areas of the body. However, there are some clinical variants showing atypical skin lesions. Here we report an unusual case of Darier's disease, which mainly showed prominent comedonal papules over the face

Global burden of peripheral artery disease and its risk factors, 1990–2019 : a systematic analysis for the Global Burden of Disease Study 2019

peripheral artery disease were modelled using the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2019 database. Prevalence, disability-adjusted life years (DALYs), and mortality estimates of peripheral artery disease were extracted from GBD 2019. Total DALYs and age-standardised DALY rate of peripheral artery disease attributed to modifiable risk factors were also assessed. Findings In 2019, the number of people aged 40 years and older with peripheral artery disease was 113 million (95% uncertainty interval [UI] 99·2–128·4), with a global prevalence of 1·52% (95% UI 1·33–1·72), of which 42·6% was in countries with low to middle Socio-demographic Index (SDI). The global prevalence of peripheral artery disease was higher in older people, (14·91% [12·41–17·87] in those aged 80–84 years), and was generally higher in females than in males. Globally, the total number of DALYs attributable to modifiable risk factors in 2019 accounted for 69·4% (64·2–74·3) of total peripheral artery disease DALYs. The prevalence of peripheral artery disease was highest in countries with high SDI and lowest in countries with low SDI, whereas DALY and mortality rates showed U-shaped curves, with the highest burden in the high and low SDI quintiles. Interpretation The total number of people with peripheral artery disease has increased globally from 1990 to 2019. Despite the lower prevalence of peripheral artery disease in males and low-income countries, these groups showed similar DALY rates to females and higher-income countries, highlighting disproportionate burden in these groups. Modifiable risk factors were responsible for around 70% of the global peripheral artery disease burden. Public measures could mitigate the burden of peripheral artery disease by modifying risk factors

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

The Impact of CSR on Corporate Value of Restaurant Businesses Using Triple Bottom Line Theory

The main goal of this study was to investigate the association between corporate social responsibility (CSR) and the value of restaurant firms by employing triple bottom line theory, a framework for a business model of sustainable development focusing on profit, environment, and people rather than just maximizing profit. Even though triple bottom line has been a common theoretical foundation in the CSR area, there is sparse literature on the theory in the context of CSR in the restaurant domain. Data regarding CSR dimensions and market-to-book value from 32 publicly traded restaurant firms in the US stock market for the period 1999–2012 were gathered, and panel data analysis methods of ordinary least square, one-way fixed effect, and time series feasible generalized least square were employed. The results revealed that economic CSR enhanced restaurant value, whereas environmental CSR diminished the value. The theoretical contribution of this study is that it will broaden the scope of triple bottom line theory. The results of the study will help restaurant administrators determine CSR policy

Preparation for an emittance exchange based bunch compression experiment at Argonne wakefield accelerator facility

The emittance exchange (EEX) is a recently developed beam manipulation method providing the longitudinal bunch compression. Since EEX converts the transverse phase space to the longitudinal phase space, it can generate a sub-fs bunch when a small bunch gets appropriate transverse focusing. Argonne Wakefield Accelerator facility (AWA) plans to demonstrate this EEX based sub-fs generation for the high frequency wakefield acceleration. The primary experiment is planned in this summer to explore the minimum achievable bunch length of current configuration. The result will indicate what upgrades we need to experimentally generate a sub-fs bunch. We present progress on the simulation work for this summer experiment and modified EEX beamline generating the sub-fs bunch as an example

Emittance Exchange Based Bunch Compression at Argonne Wakefield Accelerator Facility

An emittance exchange (EEX) beamline can manipulate longitudinal phase space via control of the transverse one at the entrance to the beamline. This EEX beamline can compress a bunch length to a sub-fs level when a specific transverse focusing is applied to the small beam at the entrance of the beamline. The Argonne Wakefield Accelerator Facility (AWA) plans to generate the sub-fs bunch for applications to wakefield accelerators. A preliminary experiment has been performed using the existing EEX beamline at AWA. In this poster, results of the experiment and feasibility of sub-fs bunch compression with a modified EEX beamline are presented. ?? 2019 IEEE