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A Concept Inventory (CI) is an assessment to measure student conceptual understanding of a particular topic. This article presents the results of a CI for basic data structures (BDSI) that has been previously shown to have strong evidence for validity. The goal of this work is to help researchers or instructors who administer the BDSI in their own courses to better understand their results. In support of this goal, we discuss our findings for each question of the CI using data gathered from 1,963 students across seven institutions.

Today’s large-scale services generally exploit loosely-coupledarchitectures that restrict functionality requiring tight cooperation (e.g.,leader election, synchronization, and reconfiguration) to a small subset ofnodes. In contrast, this work presents a way to scalably deploy tightly-coupleddistributed systems that require significant coordination among a large numberof nodes in the wide area. Our design relies upon a new reliable groupmembership abstraction to ensure that either group members are capable ofcommunicating or that new groups form. In particular, we deploy a distributedrate limiting (DRL) service within a global testbed infrastructure. Unlike mostdistributed services, DRL can safely operate in separate partitionssimultaneously, but requires timely snapshots of global state within each. OurDRL implementation leverages our proposed group membership abstraction and arobust gossip-based communication protocol, conjoining the fates of viewmaintenance and data dissemination. Through local and wide-area experiments, weillustrate that DRL remains accurate and responsive in the face of a variety offailure scenarios.Pre-2018 CSE ID: CS2012-0973

Government, medical, financial, and web-based services increasinglydepend on the ability to rapidly sift through huge, evolving data sets. Thesedata-intensive applications perform complex multi-step computations oversuccessive generations of data inflows (e.g., weekly web crawls, nightlytelescope dumps, or hourly surveillance videos). Because of the data volumesinvolved, applications must avoid reprocessing old data when new data arrivesand instead process incrementally. Unlike in stream-based systems, incomingdata does not have to be processed immediately, permitting work to be amortizedvia bulk processing. Such bulk-incremental processing represents an emergingclass of applications whose needs are not fully met by current systems. Thispaper presents a generalized architecture for bulk-incremental processingsystems (BIPS), simplifying the creation of such programs. In contrast withincremental view maintenance in data warehousing, BIPS provides flexiblelow-level primitives for managing incremental data and processing, upon whichboth relational and non-relational operations can be implemented. The paperdescribes the BIPS programming model along with several example applicationsand examines some key implementation choices. These choices are shown to play amajor role in overall system performance, via experiments on a large testbedcluster.Pre-2018 CSE ID: CS2009-0951

Oxygen transport from the lungs to peripheral tissue is dependent on the affinity of hemoglobin for oxygen. Recent experimental data have suggested that the maximum human capacity for oxygen uptake and utilization (V̇O2max) at sea level and altitude (~3000 m) is sensitive to alterations in hemoglobin‐oxygen affinity. However, the effect of such alterations on V̇O2max at extreme altitudes remains largely unknown due to the rarity of mutations affecting hemoglobin‐oxygen affinity. This work uses a mathematical model that couples pulmonary oxygen uptake with systemic oxygen utilization under conditions of high metabolic demand to investigate the effect of hemoglobin‐oxygen affinity on V̇O2max as a function of altitude. The model includes the effects of both diffusive and convective limitations on oxygen transport. Pulmonary oxygen uptake is calculated using a spatially‐distributed model that accounts for the effects of hematocrit and hemoglobin‐oxygen affinity. Systemic oxygen utilization is calculated assuming Michaelis–Menten kinetics. The pulmonary and systemic model components are solved iteratively to compute predicted arterial and venous oxygen levels. Values of V̇O2max are predicted for several values of hemoglobin‐oxygen affinity and hemoglobin concentration based on data from humans with hemoglobin mutations. The model predicts that increased hemoglobin‐oxygen affinity leads to increased V̇O2max at altitudes above ~4500 m. [ABSTRACT FROM AUTHOR]

Characterization of the elasticity of biological cells is growing as a new way to gain insight into cell biology. Cell mechanics are related to most aspects of cellular behavior, and applications in research and medicine are broad. Current methods are often limited since they require physical contact or lack resolution. From the methods available for the characterization of elasticity, those relying on high frequency ultrasound (phonons) are the most promising because they offer label-free, high (even super-optical) resolution and compatibility with conventional optical microscopes. In this Perspective contribution, we review the state of the art of picosecond ultrasonics for cell imaging and characterization, particularly for Brillouin scattering-based methods, offering an opinion for the challenges faced by the technology. The challenges are separated into biocompatibility, acquisition speed, resolution, and data interpretation and are discussed in detail along with new results. [ABSTRACT FROM AUTHOR]

The article explores the potential benefits of combining heat exposure and carbon monoxide exposure as interventions to elicit haematological adaptation and improve aerobic performance. The study found that both interventions individually increased erythropoietin (EPO) levels, but when combined, there was no additional increase in EPO. The study also investigated potential sex differences in the response to these interventions and found that females had a greater increase in EPO compared to males. The findings suggest that the combination of different stimuli may not always result in a summative response and highlight the complexity of oxygen homeostasis. [Extracted from the article]