The Atacama Rover Astrobiology Drilling Studies (ARADS) Project

With advances in commercial space launch capabilities and reduced costs to orbit, humans may arrive on Mars within a decade. Both to preserve any signs of past (and extant) martian life and to protect the health of human crews (and Earth's biosphere), it will be necessary to assess the risk of cross-contamination on the surface, in blown dust, and into the near-subsurface (where exploration and resource-harvesting can be reasonably anticipated). Thus, evaluating for the presence of life and biosignatures may become a critical-path Mars exploration precursor in the not-so-far future, circa 2030. This Special Collection of papers from the Atacama Rover Astrobiology Drilling Studies (ARADS) project describes many of the scientific, technological, and operational issues associated with searching for and identifying biosignatures in an extreme hyperarid region in Chile's Atacama Desert, a well-studied terrestrial Mars analog environment. This paper provides an overview of the ARADS project and discusses in context the five other papers in the ARADS Special Collection, as well as prior ARADS project results.

New-onset atrial fibrillation diagnosed by cardiac implantable devices in patients with hypertrophic cardiomyopathy: a systematic review and meta-analysis

Background

Atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is associated with high thromboembolic risk, morbidity, and mortality.

Purpose

We aimed to study the role of cardiac implantable devices (CID) for AF diagnosis in patients with HCM without prior AF history.

Methods

A comprehensive systematic review and meta-analysis was conducted using Pubmed, Embase, and ClinicalTrials.gov through November 2021 for studies reporting incidence of new-onset AF detected by CID including implantable cardioverter defibrillators, pacemakers, cardiac resynchronization therapy, and loop recorder devices in HCM patients. We used a Freeman-Tukey transformation to calculate the weighted summary proportion of the incidence of AF and stroke and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random-effects model.

Results

Eight cohort studies were included, totalizing 910 patients with HCM and CID without baseline AF. Mean age was 54 years and 21% were female. Mean left ventricular wall thickness was 22.6 mm. Mean follow-up was 3.1 years. New-onset AF was detected in 27.6% (95% CI 18.7–37.5) of patients (Figure A) and 84% of the episodes were subclinical. Stroke occurred in 4.7% (95% CI 1.8–9.0) of patients without baseline AF (Figure B). There was no significant difference in the unadjusted risk of stroke between patients with newly diagnosed AF vs no AF detected at the end of follow-up (9.4% vs 4.7%, OR 1.93, 95% CI 0.83–4.48, p=0.13).

Conclusion

There is a high incidence of subclinical new-onset AF in patients with HCM, supporting the use of CID for early detection of AF in this population.

Funding Acknowledgement

Type of funding sources: None.

A retrospective, single-center cohort study on complications after dental extractions in patients taking biologic agents

BACKGROUND

Although biologic agents represent a growing class of therapeutics, little is known about how these agents affect the provision of dental treatment.

METHODS

This retrospective case-control study analyzed patients undergoing dental extraction treated with biologic agents from 2017 through 2020. Complications within 30 days postextraction were recorded.

RESULTS

One-hundred twenty-one patients were treated during 147 encounters. Fifteen patients experienced complications during 16 encounters. Notable or excessive pain was most common (14/16; 88%). Patients who experienced complications were treated with 7 biologic agents: dulaglutide, belimumab, adalimumab, aflibercept, tofacitinib, ranibizumab, and ixekizumab. Complication after extraction-specifically, pain-was elevated for patients receiving aflibercept and ranibizumab. When grouped by class, complications were more common with vascular endothelial growth factor antagonism.

CONCLUSIONS

The impact of biologics on the provision of and recovery after dental treatment remains unknown. Pain was most commonly reported. Patients treated with vascular endothelial growth factor antagonists experienced an elevated rate of complications.

PRACTICAL IMPLICATIONS

This study provides preliminary data on how patients taking biologic agents heal after dental extraction. It is limited by small sample sizes. Further work will build on this data to determine appropriate management of patients taking biologics in the dental setting.

Remote neuropsychological evaluation of older adults

The use of technological means in the process of neuropsychological assessment has been proposed as a technique with promising results in the field of detection of neurocognitive disorders for community-dwelling older adults. Especially during the pandemic period due to COVID-19, telemedicine assumed to be vital in the field of early diagnosis of cognitive disorders and highlighted the clinical utility of remote methods of neuropsychological assessmentby video-conference. This descriptive study presents the development of a remote neuropsychological assessment protocol by selecting appropriate validated tests as part of a more comprehensive evaluation for older adults dwelling in the community. We recruited participants from the Athens Alzheimer's Association center in collaboration with the Hellenic Neuropsychological Society, in Athens, Greece, regarding the period between April 2020 and October 2021. 90 individuals, tested for the first time, were categorized into three groups according to their diagnosis which included: (a) Mild Cognitive Impairment (MCI), (b) Alzheimer's disease, (c) cognitively healthy older adults. The presented protocol outlines the main considerations of a framework about remote neuropsychological assessment, which can maximize the effectiveness of interventions and continuity regarding the care of older adults. The recommendations outlined in the presented protocol highlight strengths and limitations that should be taken into account in remote control procedures. Although the protocol was created in response to pandemic restrictions, tele-neuropsychology shows promise as a way to improve access opportunity to neurodiagnostic services for rural aging and underserved populations, which lack specialized healthcare services. Further application to different populations will add validity to the presented descriptive protocol.

Midlatitude ice-rich ground on mars as a target in the search for evidence of life and for in situ resource utilization on human missions

Midlatitude ground ice on Mars is of significant scientific interest for understanding the history and evolution of ice stability on Mars and is relevant for human exploration as a possible in situ resource. For both science and exploration, assessing the astrobiological potential of the ice is important in terms of (1) understanding the potential for life on Mars and (2) evaluating the presence of possible biohazards in advance of human exploration. In the present study, we review the evidence for midlatitude ground ice on Mars, discuss the possible explanations for its occurrence, and assess its potential habitability. During the course of study, we systematically analyzed remote-sensing data sets to determine whether a viable landing site exists in the northern midlatitudes to enable a robotic mission that conducts in situ characterization and searches for evidence of life in the ice. We classified each site according to (1) presence of polygons as a proxy for subsurface ice, (2) presence and abundance of rough topographic obstacles (e.g., large cracks, cliffs, uneven topography), (3) rock density, (4) presence and abundance of large boulders, and (5) presence of craters. We found that a suitable landing site exists within Amazonis Planitia near ground ice that was recently excavated by a meteorite impact.

Simultaneous wavenumber measurement and coherence detection using temporal phase unwrapping

Wavelength scanning interferometry and swept-source optical coherence tomography require accurate measurement of time-varying laser wavenumber changes. We describe here a method based on recording interferograms of multiple wedges to provide simultaneously high wavenumber resolution and immunity to the ambiguities caused by large wavenumber jumps. All the data required to compute a wavenumber shift are provided in a single image, thereby allowing dynamic wavenumber monitoring. In addition, loss of coherence of the laser light is detected automatically. The paper gives details of the analysis algorithms that are based on phase detection by a two-dimensional Fourier transform method followed by temporal phase unwrapping and correction for optical dispersion in the wedges. A simple but robust method to determine the wedge thicknesses, which allows the use of low-cost optical components, is also described. The method is illustrated with experimental data from a Ti:sapphire tunable laser, including independent wavenumber measurements with a commercial wavemeter. A root mean square (rms) difference in measured wavenumber shift between the two of ~4 m⁻¹ has been achieved, equivalent to an rms wavelength shift error of ~0.4 pm.

Some empirical data concerning time of day effects on conditioned freezing in an aversive context-conditioning procedure

The primary purpose of this article is to present some empirical data concerning three different potential time of day effects on conditioned freezing in a commonly-used aversive context-conditioning procedure with an unsignalled electric footshock as the unconditioned stimulus. In Experiment 1, rats were repeatedly placed in a conditioning box in which they received a shock. For one group of rats, these sessions consistently occurred in the morning; for another group in the afternoon. In Experiments 2 and 3, rats received two training sessions per day. One group was consistently shocked in a training box on morning sessions but not on afternoon or evening sessions, whereas another group received the reverse treatment. The pattern of freezing observed during repeated non-shock morning and afternoon/evening test sessions reflected an effect of time of shock delivery on the acquisition of a context-shock association in Experiments 1 and 2, and a time of testing, or non-specific performance, effect in Experiments 1 and 3. In none of the experiments was there an effect that would reflect differential retrieval of a context-shock association by time cues. These results were discussed in the light of data from previous experiments.

Digital processing of electronic speckle pattern interferometry addition fringes

A digital image-processing method for analyzing double-pulsed electronic speckle pattern interferometry addition fringes is described. The procedure consists of three steps, forming a combination particularly suited to addressing some important practical limitations of the measurement system. In the first step it is shown that in certain cases fringe visibility may be enhanced by subtraction of a reference interferogram, so that a pattern with a quality similar to that of a subtraction one is obtained. In the second step noise is reduced by the application of a spectral subtraction image-restoration method. The third step concerns the calculation of the wrapped phase by means of a Fourier transform method with bandpass filtering. Preliminary experimental results that illustrate the performance of this approach are presented.

Chicano return migration to the Southwest: an integrated human capital approach

"This study uses an integrated human capital framework to examine the relationship between human capital, employment and ethnic factors and return migration to the Southwest [United States] among Chicanos. The sample used in the study is derived from the 1980 Public Use Microdata Samples and contains 1,926 Chicano householders between the ages of 25 and 64 who were born in one of five southwest states, lived outside of this region in 1975, and worked in the civilian labor force at any time between 1975 and 1980. The results suggest that various human capital, employment and ethnic composition variables are important predictors of Chicano return migration."

The effect of maquiladora employment on the monthly flow of Mexican undocumented immigration to the U.S., 1978-1982

"Some controversy has surrounded the extent to which employment in maquiladoras (assembly plants located along the Mexican border) has stimulated undocumented immigration to the United States. This study uses monthly data of maquiladora employment and INS [Immigration and Naturalization Service] apprehensions in a 'push-pull' migration framework to study the association between these two variables during the April 1978 to January 1982 period. The findings suggest that there is a significantly negative relationship between the one month lag of maquiladora employment and INS apprehensions. Employment growth in the maquiladora sector tends to be followed by a reduction of apprehensions one month later. The study also finds that male and female apprehensions appear to respond to relatively similar economic factors."

Simultaneous imaging of periodic object planes

When a zone plate is inserted in the frequency plane of an ordinary 4- f coherent optical processor, self-images are observed at the end of the system. From symmetry considerations we may expect that the same system would image periodic object planes into a single image plane. In this paper we discuss both phenomena assuming incoherent illumination. In the last instance, most of our discussion is oriented to explain the simultaneous imaging of periodic object planes. Experimental results are presented to illustrate both phenomena.

The seasonality of apprehensions of undocumented Mexican workers

"This article uses within-year apprehensions data to test the economic determinants of Mexican undocumented immigration to the United States. These data are highly seasonal and within-year border patrol apprehensions suggest that this seasonality is not solely due to changes in border patrol enforcement." It is found that both supply and demand variables affect apprehensions and that agricultural factors appear to be important determinants of the variations in apprehensions. The results are similar to those of earlier studies

Rotavirus infection in children with acute gastroenteritis in Ecuador

Electron microscopic examination of stools of 702 infants and young children hospitalized in the Emergency Service of the Alejandro Mann Children's Hospital in Guayaquil, Ecuador, between August 1978 and October 1979 showed rotavirus to be present in 148 (21.1%). During the study period rotavirus was detected throughout the year, with no distinct seasonal variation. In addition to rotavirus, adenovirus was detected in stools of five (0.7%) of the patients and unidentified small round virus particles in seven (1.0%).