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The COVID-19 pandemic has produced significant psychological distress for college students due to the sudden proliferation of stressors. We examine whether and how self and parental immigration status contributes to Latina/o/x college students' mental health and pandemic stressors during the initial months of the pandemic. We draw on quantitative and qualitative survey data collected in March-June 2020 with 1,600 Latina/o/x University of California undergraduate students from three self-identified groups: undocumented students, US citizens with at least one undocumented parent, and US citizens with lawfully present parents. Quantitative analyses reveal that the pandemic produced widespread negative mental health effects but the severity of these effects did not differ by self/parental immigration status. Our qualitative analyses identify common pandemic-related stressors across our three student groups (financial insecurity, COVID-19 virus concerns, academic strains, and social dynamics); however, undocumented students and US citizens with undocumented parents identify unique aspects of these stressors due to legal vulnerabilities. Self and parental undocumented status also compromises the ability to manage common pandemic stressors because of immigration status-related exclusion from necessary resources. Ultimately, we argue that the high-stress nature of the pandemic elevated mental distress across all student groups, but the structural exclusion of undocumented immigrants contributes to unique experiences of stress among Latina/o/x undocumented students and US citizen students with undocumented parents.

Moving toward exascale computing, the size of data stored and accessed by applications is ever increasing. However, traditional disk-based storage has not seen improvements that keep up with the explosion of data volume or the speed of processors. Multiple levels of non-volatile storage devices are being added to handle bursty I/O, however, moving data across the storage hierarchy can take longer than the data generation or analysis. Asynchronous I/O can reduce the impact of I/O latency as it allows applications to schedule I/O early and to check their status later. I/O is thus overlapped with application communication or computation or both, effectively hiding some or all of the I/O latency. POSIX and MPI-I/O provide asynchronous read and write operations, but lack the support for non-data operations such as file open and close. Users also have to manually manage data dependencies and use low-level byte offsets, which requires significant effort and expertise to adopt. In this article, we present an asynchronous I/O framework that supports all types of I/O operations, manages data dependencies transparently and automatically, provides implicit and explicit modes for application flexibility, and error information retrieval. We implemented these techniques in HDF5. Our evaluation of several benchmarks and application workloads demonstrates it effectiveness on hiding the I/O cost from the application.

Using observational data and model hindcasts produced by a coupled climate model, we examine the response of the East Asian winter monsoon (EAWM) to three types of El Niño: eastern Pacific (EP) and central Pacific I (CP-I) and II (CP-II) El Niños. The observational analysis shows that all three El Niño types weaken the EAWM with varying degrees of impact. The EP El Niño has the largest weakening effect, while the CP-II El Niño has the second largest, and the CP-I El Niño has the smallest. We find that diverse El Niño types impact the EAWM by altering the responses of two anomalous anticyclones during El Niño mature winter: the western North Pacific anticyclone (WNPAC) and Kuroshio anticyclone (KAC). The WNPAC responses are controlled by the Gill response and Indian Ocean warming processes that both respond to the eastern-to-central tropical Pacific precipitation anomalies. The KAC responses are controlled by a poleward wave propagation responding to the northwestern tropical Pacific precipitation anomalies. We find that the model hindcasts significantly underestimate the weakening effect during the EP and CP-II El Niños. These underestimations are related to a model deficiency in which it produces a too-weak WNPAC response during the EP El Niño and completely misses the KAC response during both types of El Niño. The too-weak WNPAC response is caused by the model deficiency of simulating too-weak eastern-to-central tropical Pacific precipitation anomalies. The lack of KAC response arises from the unrealistic response of the model’s extratropical atmosphere to the northwestern tropical Pacific precipitation anomalies.

In the observations, El Niño events initiated by a subtropical Pacific mechanism (SP-onset El Niños) show larger uncertainty in their decay evolution patterns than those initiated by a tropical Pacific mechanism. A 2,200-year simulation of Community Earth System Model reproduces this observed feature and its SP-onset El Niños are analyzed to understand the cause of the large uncertainty. Results show that the onset location of SP-onset El Niño, which interacts with the eastern edge of the western Pacific warm pool, is a key factor controlling its decay evolution. When the onset is located east (west) of 155°E, the event has a strong tendency to reverse (maintain) its phase, leading to cyclic (multiyear) evolution. These two onset locations respectively activate Indo-Pacific and tropical-subtropical Pacific interactions to give rise to the different evolution patterns. The findings offer a potential way to predict the evolution of SP-onset El Niños using their onset locations.

Applying statistical analyses to reanalysis products during the period 1900–2018, this study finds the 11-year solar cycle to have a significant correlation with sea surface temperature (SST) variations in the Northeastern Pacific. The solar influence is first manifested and amplified in the lower stratosphere, which then alters the strength of Hadley circulation in the troposphere. Lastly, the changes in the sinking branch of the Hadley circulation modulate surface heat fluxes to give rise to the SST footprint. The footprint has a structure similar to that of the Pacific meridional mode (PMM) that is known to be an important trigger of the central Pacific (CP) type of the El Niño-Southern Oscillation (ENSO). The 11-year solar cycle is thus shown to contribute to the slow modulation of the CP ENSO and, in particular, to be associated with more CP El Niño (La Niña) events during the active (inactive) phase of the cycle.

ObjectiveThe Wechsler Adult Intelligence Scale (WAIS) processing speed subtests are among the most ubiquitous indices of processing speed in the field. The aim of this study was to develop and examine demographically-adjusted normative data for Spanish language versions of the WAIS-III Digit Symbol Coding (DSC) and Symbol Search (SS) subtests for US-dwelling Spanish-speakers living in the US/Mexico border region.MethodsThe sample included 203 healthy participants who were part of the larger Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project (DSC: n = 201; SS: n = 200).ResultsOlder age and higher education were both related to lower scores on the DSC and SS subtests (all ps  .05). Raw-to-scaled score conversions were calculated for both subtests, and fractional polynomial equations were derived to compute demographically-adjusted T-scores accounting for age, education, and gender for each subtest and the Processing Speed Index. Published norms for English-speaking non-Hispanic white adults slightly overestimated impairment rates (T-scores

ObjectiveThis paper summarizes the findings of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project and offers a roadmap for future research.MethodsThe NP-NUMBRS project represents the largest and most comprehensive co-normed neuropsychological battery to date for native Spanish-speaking healthy adults from the U.S. (California/Arizona)-Mexico borderland region (N = 254; ages 19-60 years). These norms provide demographic adjustments for tests across numerous domains (i.e., verbal fluency, processing speed, attention/working memory, executive function, episodic memory [learning and delayed recall], visuospatial, and fine motor skills).ConclusionsThis project: 1) shows that the NP-NUMBRS norms consistently outperformed previously published norms for English-speaking non-Hispanic (White and African-American) adults in identifying impairment; 2) explores the role of Spanish-English bilingualism in test performance; and 3) provides support for the diagnostic validity of these norms in detecting HIV-associated neurocognitive impairment. Study limitations include the limited assessment of sociocultural variables and generalizability (e.g., other Latina/o populations, age limit [19 - 60 years]). Future research is needed to: 1) investigate these norms with U.S.-dwelling Spanish-speakers of non-Mexican heritage and other clinical subpopulations; 2) expand coverage of cognitive domains (e.g. language, visuospatial); 3) develop large normative datasets for children and older Latina/o populations; 4) examine how sociocultural factors impact performance (e.g., bilingualism, acculturation); 5) investigate these norms' diagnostic and ecological validity; and 6) develop norms for neurocognitive change across time. It is hoped that the NP-NUMBRS norms will aid researchers and clinicians working with U.S.-dwelling Spanish-speakers from the U.S.-Mexico borderland to conduct research and evidence-based neuropsychological evaluations in a more culturally responsive and ethical manner.

Two-phase I/O is a well-known strategy for implementing collective MPI-IO functions. It redistributes I/O requests among the calling processes into a form that minimizes the file access costs. As modern parallel computers continue to grow into the exascale era, the communication cost of such request redistribution can quickly overwhelm collective I/O performance. This effect has been observed from parallel jobs that run on multiple compute nodes with a high count of MPI processes on each node. To reduce the communication cost, we present a new design for collective I/O by adding an extra communication layer that performs request aggregation among processes within the same compute nodes. This approach can significantly reduce inter-node communication contention when redistributing the I/O requests. We evaluate the performance and compare it with the original two-phase I/O on Cray XC40 parallel computers (Theta and Cori) with Intel KNL and Haswell processors. Using I/O patterns from two large-scale production applications and an I/O benchmark, we show our proposed method effectively reduces the communication cost and hence maintains the scalability for a large number of processes.

Scientific applications at exascale generate and analyze massive amounts of data. A critical requirement of these applications is the capability to access and manage this data efficiently on exascale systems. Parallel I/O, the key technology enables moving data between compute nodes and storage, faces monumental challenges from new applications, memory, and storage architectures considered in the designs of exascale systems. As the storage hierarchy is expanding to include node-local persistent memory, burst buffers, etc., as well as disk-based storage, data movement among these layers must be efficient. Parallel I/O libraries of the future should be capable of handling file sizes of many terabytes and beyond. In this paper, we describe new capabilities we have developed in Hierarchical Data Format version 5 (HDF5), the most popular parallel I/O library for scientific applications. HDF5 is one of the most used libraries at the leadership computing facilities for performing parallel I/O on existing HPC systems. The state-of-the-art features we describe include: Virtual Object Layer (VOL), Data Elevator, asynchronous I/O, full-featured single-writer and multiple-reader (Full SWMR), and parallel querying. In this paper, we introduce these features, their implementations, and the performance and feature benefits to applications and other libraries.

A technique is developed to identify the types of atmosphere-ocean interaction during El Niño-Southern Oscillation events using sea surface temperature, sea level pressure (SLP), and outgoing longwave radiation (OLR) data. Two pairs of indices are derived that separate the interactions into tropical and subtropical types and basin-wide and local types. The dominant interaction type for the observed El Niño events since 1980 is identified and shown to shift with time from the tropical to subtropical and from basin-wide to local. Thus, the 21st century El Niños have become dominated by subtropical and local interactions, in strong contrast to the 20th century El Niños that were dominated by the tropical and basin-wide interactions. These changes result in the 1997-98 and 2015-16 extreme El Niños being different in their evolutions and global impacts, despite having similar intensities. SLP is the key variable for separating the tropical and subtropical types of interactions, while OLR is the key variable for separating the basin-wide and local types of interactions.

The low solubility of the iron, manganese and zinc oxides in the pH range of calcareous soils contributes, among other factors, to the low availability of these nutrients to plants. The aim of this work was study the efficacy of the application of Fe, Mn, Zn and Cu chelates to correct the deficiencies in soybean in hydroponic solution in the presence of CaCO3. Fe was applied as o,oEDDHA/Fe3+ in all the cases while Mn, Zn and Cu were applied as o,pEDDHA, EDDS, EDTA, HEDTA or DTPA chelates, with the same chelating agent for the three metals in the same treatment and two additional treatments with Mn and Cu chelated by EDTA and Zn chelated by o,pEDDHA or EDDS. Three controls with no Mn, no Zn and no Mn and Zn with the others chelated by EDTA were tested too. Results indicate that the content of Fe in leaf was similar in all the treatments due the same chelated was applied. The treatments that presented the higher levels for Mn and Zn in leaf, especially for Zn, was the one with the application of Mn and Zn as o,pEDDHA. The higher level for Cu was produced in the treatment with EDTA. It seems that the less stable phenolic chelates for Mn and Zn, like o,pEDDHA, are adequate for the nutrition of Mn and Zn in hydroponics due the low competence of this chelating agent with the plant for the metals.

In theories with multiple vacua, reheating to a temperature greater than the height of a barrier can stimulate transitions from a desirable metastable vacuum to a lower energy state. We discuss the constraints this places on various theories and demonstrate that in a class of supersymmetric models this transition does not occur even for arbitrarily high reheating temperature.