Showing papers by "San Francisco State University published in 2015"

Immigration as a social determinant of health

Abstract: Although immigration and immigrant populations have become increasingly important foci in public health research and practice, a social determinants of health approach has seldom been applied in this area. Global patterns of morbidity and mortality follow inequities rooted in societal, political, and economic conditions produced and reproduced by social structures, policies, and institutions. The lack of dialogue between these two profoundly related phenomena-social determinants of health and immigration-has resulted in missed opportunities for public health research, practice, and policy work. In this article, we discuss primary frameworks used in recent public health literature on the health of immigrant populations, note gaps in this literature, and argue for a broader examination of immigration as both socially determined and a social determinant of health. We discuss priorities for future research and policy to understand more fully and respond appropriately to the health of the populations affected by this global phenomenon.

Plasticity in thermal tolerance has limited potential to buffer ectotherms from global warming.

Abstract: Global warming is increasing the overheating risk for many organisms, though the potential for plasticity in thermal tolerance to mitigate this risk is largely unknown. In part, this shortcoming stems from a lack of knowledge about global and taxonomic patterns of variation in tolerance plasticity. To address this critical issue, we test leading hypotheses for broad-scale variation in ectotherm tolerance plasticity using a dataset that includes vertebrate and invertebrate taxa from terrestrial, freshwater and marine habitats. Contrary to expectation, plasticity in heat tolerance was unrelated to latitude or thermal seasonality. However, plasticity in cold tolerance is associated with thermal seasonality in some habitat types. In addition, aquatic taxa have approximately twice the plasticity of terrestrial taxa. Based on the observed patterns of variation in tolerance plasticity, we propose that limited potential for behavioural plasticity (i.e. behavioural thermoregulation) favours the evolution of greater plasticity in physiological traits, consistent with the ‘Bogert effect’. Finally, we find that all ectotherms have relatively low acclimation in thermal tolerance and demonstrate that overheating risk will be minimally reduced by acclimation in even the most plastic groups. Our analysis indicates that behavioural and evolutionary mechanisms will be critical in allowing ectotherms to buffer themselves from extreme temperatures.

The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. I. Overview of the Project and Detection of Multiple Stellar Populations

Abstract: In this paper we describe a new UV-initiative Hubble Space Telescope project (GO-13297) that will complement the existing F606W and F814W database of the Advanced Camera for Surveys Globular Cluster (GC) Treasury by imaging most of its clusters through UV/blue WFC3/UVIS filters F275W, F336W, and F438W. This “magic trio” of filters has shown an uncanny ability to disentangle and characterize multiple population (MP) patterns in GCs in a way that is exquisitely sensitive to C, N, and O abundance variations. Combination of these passbands with those in the optical also gives the best leverage for measuring helium enrichment. The dozen clusters that had previously been observed in these bands exhibit a bewildering variety of MP patterns, and the new survey will map the full variance of the phenomenon. The ubiquity of multiple stellar generations in GCs has made the formation of these cornerstone objects more intriguing than ever; GC formation and the origin of their MPs have now become one and the same problem. In this paper we will describe the database and our data reduction strategy, as well as the uses we intend to make of the final photometry, astrometry, and PMs. We will also present preliminary color–magnitude diagrams from the data so far collected. These diagrams also draw on data from GO-12605 and GO-12311, which served as a pilot project for the present GO-13297.

The Canadian Cluster Comparison Project: detailed study of systematics and updated weak lensing masses

Abstract: Masses of clusters of galaxies from weak gravitational lensing analyses of ever larger samples are increasingly used as the reference to which baryonic scaling relations are compared. In this paper we revisit the analysis of a sample of 50 clusters studied as part of the Canadian Cluster Comparison Project. We examine the key sources of systematic error in cluster masses. We quantify the robustness of our shape measurements and calibrate our algorithm empirically using extensive image simulations. The source redshift distribution is revised using the latest state-of-the-art photometric redshift catalogues that include new deep near-infrared observations. None the less we find that the uncertainty in the determination of photometric redshifts is the largest source of systematic error for our mass estimates. We use our updated masses to determine b, the bias in the hydrostatic mass, for the clusters detected by Planck. Our results suggest 1 − b = 0.76 ± 0.05 (stat) ± 0.06 (syst), which does not resolve the tension with the measurements from the primary cosmic microwave background.

Probing excitonic states in suspended two-dimensional semiconductors by photocurrent spectroscopy

Abstract: The optical response of semiconducting monolayer transition-metal dichalcogenides (TMDCs) is dominated by strongly bound excitons that are stable even at room temperature. However, substrate-related effects such as screening and disorder in currently available specimens mask many anticipated physical phenomena and limit device applications of TMDCs. Here, we demonstrate that that these undesirable effects are strongly suppressed in suspended devices. Extremely robust (photogain > 1,000) and fast (response time < 1 ms) photoresponse allow us to study, for the first time, the formation, binding energies, and dissociation mechanisms of excitons in TMDCs through photocurrent spectroscopy. By analyzing the spectral positions of peaks in the photocurrent and by comparing them with first-principles calculations, we obtain binding energies, band gaps and spin-orbit splitting in monolayer TMDCs. For monolayer MoS2, in particular, we obtain an extremely large binding energy for band-edge excitons, Ebind ≥ 570 meV. Along with band-edge excitons, we observe excitons associated with a van Hove singularity of rather unique nature. The analysis of the source-drain voltage dependence of photocurrent spectra reveals exciton dissociation and photoconversion mechanisms in TMDCs.

Successful Aging and Its Discontents: A Systematic Review of the Social Gerontology Literature

Abstract: Purpose of the study The purpose of this study was to analyze the range of critiques of successful aging models and the suggestions for improvement as expressed in the social gerontology literature. Design and methods We conducted a systematic literature review using the following criteria: journal articles retrieved in the Abstracts in Social Gerontology, published 1987-2013, successful aging/ageing in the title or text (n = 453), a critique of successful aging models as a key component of the article. Sixty-seven articles met the criteria. Qualitative methods were used to identify key themes and inductively configure meanings across the range of critiques. Results The critiques and remedies fell into 4 categories. The Add and Stir group suggested a multidimensional expansion of successful aging criteria and offered an array of additions. The Missing Voices group advocated for adding older adults' subjective meanings of successful aging to established objective measures. The Hard Hitting Critiques group called for more just and inclusive frameworks that embrace diversity, avoid stigma and discrimination, and intervene at structural contexts of aging. The New Frames and Names group presented alternative ideal models often grounded in Eastern philosophies. Implications The vast array of criteria that gerontologists collectively offered to expand Rowe and Kahn's original successful model is symptomatic of the problem that a normative model is by definition exclusionary. Greater reflexivity about gerontology's use of "successful aging" and other normative models is needed.

Kepler Eclipsing Binary Stars. VII. The Catalog of Eclipsing Binaries Found in the Entire Kepler Data-Set

Abstract: The primary Kepler Mission provided nearly continuous monitoring of ~200,000 objects with unprecedented photometric precision. We present the final catalog of eclipsing binary systems within the 105 square degree Kepler field of view. This release incorporates the full extent of the data from the primary mission (Q0-Q17 Data Release). As a result, new systems have been added, additional false positives have been removed, ephemerides and principal parameters have been recomputed, classifications have been revised to rely on analytical models, and eclipse timing variations have been computed for each system. We identify several classes of systems including those that exhibit tertiary eclipse events, systems that show clear evidence of additional bodies, heartbeat systems, systems with changing eclipse depths, and systems exhibiting only one eclipse event over the duration of the mission. We have updated the period and galactic latitude distribution diagrams and included a catalog completeness evaluation. The total number of identified eclipsing and ellipsoidal binary systems in the Kepler field of view has increased to 2878, 1.3% of all observed Kepler targets. An online version of this catalog with downloadable content and visualization tools is maintained at this http URL

Mindfulness Revisited A Buddhist-Based Conceptualization

Abstract: Recent scholarship on mindfulness has narrowly focused on attention enhancement, present-moment awareness, and its stress reduction effects. Moreover, current operational definitions of mindfulness...

Social Support Networks for LGBT Young Adults: Low Cost Strategies for Positive Adjustment

Abstract: Lesbian, gay, bisexual, and transgender (LGBT) youth and young adults are known to have compromised physical and mental health, and family rejection has been found to be an important risk factor. Yet few studies have examined the positive role that support from parents, friends, and the community have for LGBT young adults. In a cross-sectional study of 245 LGBT non-Latino White and Latino young adults (ages 21–25) in the United States, sexuality-related social support was examined in association with measures of adjustment in young adulthood. Family, friend, and community support were strong predictors of positive outcomes, including life situation, self-esteem, and LGBT esteem. However, family acceptance had the strongest overall influence when other forms of support were considered. Implications for the unique and concurrent forms of social support for LGBT youth and young adult adjustment are discussed.

A National Survey of Faculty Knowledge, Experience, and Readiness for Teaching Lesbian, Gay, Bisexual, and Transgender Health in Baccalaureate Nursing Programs

Abstract: AIM This article assesses the knowledge of faculty in baccalaureate nursing programs and their readiness to teach about lesbian, gay, bisexual, and transgender (LGBT) health. BACKGROUND Although health disparities affecting the LGBT population are increasingly acknowledged in the literature, a dearth of information exists on how LGBT health is integrated in nursing programs. METHOD A survey was sent to a nonprobability purposive sample of nursing school administrative leaders (N = 739); they were asked to share the link with their faculty. More than 1,000 faculty completed the survey. RESULTS The knowledge, experience, and readiness for teaching LGBT health among baccalaureate faculty are limited. LGBT faculty reported greater awareness, knowledge, and readiness compared with heterosexual faculty. The estimated median time devoted to teaching LGBT health was 2.12 hours. CONCLUSION Findings will help inform the design of faculty development programs and guide in aligning the curricula with current...

Minority Stress and Stress Proliferation among Same-Sex and Other Marginalized Couples

Abstract: Drawing from 2 largely isolated approaches to the study of social stress-stress proliferation and minority stress-the authors theorize about stress and mental health among same-sex couples. With this integrated stress framework, they hypothesized that couple-level minority stressors may be experienced by individual partners and jointly by couples as a result of the stigmatized status of their same-sex relationship-a novel concept. They also consider dyadic minority stress processes, which result from the relational experience of individual-level minority stressors between partners. Because this framework includes stressors emanating from both status- (e.g., sexual minority) and role-based (e.g., partner) stress domains, it facilitates the study of stress proliferation linking minority stress (e.g., discrimination), more commonly experienced relational stress (e.g., conflict), and mental health. This framework can be applied to the study of stress and health among other marginalized couples, such as interracial/ethnic, interfaith, and age-discrepant couples.

Empowering Employee Sustainability: Perceived Organizational Support Toward the Environment

Abstract: This paper contributes to the ongoing discussion of sustainability behaviors by introducing the construct of perceived organizational support toward the environment (POS-E). We propose and empirically test an integrated model whereby we test the association of POS-E with employees’ organizational citizenship behaviors toward the environment (OCB-E) as well as to job attitudes. Results indicated that POS-E was positively related to OCB-E, job satisfaction, organizational identification, and psychological empowerment, and negatively related to turnover intentions. We also found that psychological empowerment partially mediated the relationship between POS-E and the dependent variables. We discuss the theoretical implications as well as practical implications for managers seeking to encourage sustainability in their organizations.

To what extent do teacher–student interaction quality and student gender contribute to fifth graders’ engagement in mathematics learning?

Abstract: This study examines concurrent teacher–student interaction quality and 5th graders’ (n = 387) engagement in mathematics classrooms (n = 63) and considers how teacher–student interaction quality relates to engagement differently for boys and girls Three approaches were used to measure student engagement in mathematics: Research assistants observed engaged behavior, teachers reported on students’ engagement, and students completed questionnaires Engagement data were conducted 3 times per year concurrent with measures of teacher–student interaction quality Results showed small but statistically significant associations among the 3 methods Results of multilevel models showed only 1 significant finding linking quality of teacher–student interactions to observed or teacher-reported behavioral engagement; higher classroom organization related to higher levels of observed behavioral engagement However, the multilevel models produced a rich set of findings for student-reported engagement Students in classrooms with higher emotional support reported higher cognitive, emotional, and social engagement Students in classrooms higher in classroom organization reported more cognitive, emotional, and social engagement Interaction effects (Gender × Teacher–student interaction quality) were present for student-reported engagement outcomes but not in observed or teacher-reported engagement Boys (but not girls) in classrooms with higher observed classroom organization reported more cognitive and emotional engagement In classrooms with higher instructional support, boys reported higher but girls reported lower social engagement The discussion explores implications of varied approaches to measuring engagement, interprets teacher–student interaction quality and gender findings, and considers the usefulness of student report in understanding students’ math experiences

Vladimir Putin's last stand: the sources of Russia's Ukraine policy

Abstract: The paper studies Russia's Ukraine policy since the Orange Revolution. Russia's policy toward its western neighbor has evolved from unhappy relations with Victor Yushchenko to rapprochement with Victor Yanukovich and then confrontation over the revolutionary power change in Kiev in February 2014. The paper argues that Vladimir Putin's actions following February revolution in Kiev demonstrate both change and continuity in Russia's foreign policy. Although these actions constituted a major escalation, relative to Russia's previous behavior toward Ukraine, the escalation of relations with Kiev also reflected a broader policy pattern of Russia's assertive relations with the Western nations adopted by the Kremlin since the mid-2000s. What made Russia's conflict with Ukraine possible, even inevitable, was the West's lack of recognition for Russia's values and interests in Eurasia, on the one hand, and the critically important role that Ukraine played in the Kremlin's foreign policy calculations, on the other. T...

RENO: a high-efficient reconfigurable neuromorphic computing accelerator design

Abstract: Neuromorphic computing is recently gaining significant attention as a promising candidate to conquer the well-known von Neumann bottleneck. In this work, we propose RENO -- a efficient reconfigurable neuromorphic computing accelerator. RENO leverages the extremely efficient mixed-signal computation capability of memristor-based crossbar (MBC) arrays to speedup the executions of artificial neural networks (ANNs). The hierarchically arranged MBC arrays can be configured to a variety of ANN topologies through a mixed-signal interconnection network (M-Net). Simulation results on seven ANN applications show that compared to the baseline general-purpose processor, RENO can achieve on average 178.4x (27.06x) performance speedup and 184.2x (25.23x) energy savings in high-efficient multilayer perception (high-accurate auto-associative memory) implementation. Moreover, in the comparison to a pure digital neural processing unit (D-NPU) and a design with MBC arrays co-operating through a digital interconnection network, RENO still achieves the fastest execution time and the lowest energy consumption with similar computation accuracy.

Kepler 453 b - The 10th Kepler transiting circumbinary planet

Abstract: We present the discovery of Kepler-453 b, a 6.2 R⊕ planet in a low-eccentricity, 240.5 day orbit about an eclipsing binary. The binary itself consists of a 0.94 and 0.195 M⊙ pair of stars with an orbital period of 27.32 days. The plane of the planet's orbit is rapidly precessing, and its inclination only becomes sufficiently aligned with the primary star in the latter portion of the Kepler data. Thus three transits are present in the second half of the light curve, but none of the three conjunctions that occurred during the first half of the light curve produced observable transits. The precession period is ~103 years, and during that cycle, transits are visible only ~8.9% of the time. This has the important implication that for every system like Kepler-453 that we detect, there are ~11.5 circumbinary systems that exist but are not currently exhibiting transits. The planet's mass is too small to noticeably perturb the binary, and consequently its mass is not measurable with these data; however, our photodynamical model places a 1σ upper limit of 16 M⊕. With a period 8.8 times that of the binary, the planet is well outside the dynamical instability zone. It does, however, lie within the habitable zone of the binary, making it the third of 10 Kepler circumbinary planets to do so.

Zombie vortex instability. i. a purely hydrodynamic instability to resurrect the dead zones of protoplanetary disks

Abstract: There is considerable interest in hydrodynamic instabilities in dead zones of protoplanetary disks as a mechanism for driving angular momentum transport and as a source of particle-trapping vortices to mix chondrules and incubate planetesimal formation. We present simulations with a pseudo-spectral anelastic code and with the compressible code Athena, showing that stably stratified flows in a shearing, rotating box are violently unstable and produce space-filling, sustained turbulence dominated by large vortices with Rossby numbers of order ~0.2–0.3. This Zombie Vortex Instability (ZVI) is observed in both codes and is triggered by Kolmogorov turbulence with Mach numbers less than ~0.01. It is a common view that if a given constant density flow is stable, then stable vertical stratification should make the flow even more stable. Yet, we show that sufficient vertical stratification can be unstable to ZVI. ZVI is robust and requires no special tuning of boundary conditions, or initial radial entropy or vortensity gradients (though we have studied ZVI only in the limit of infinite cooling time). The resolution of this paradox is that stable stratification allows for a new avenue to instability: baroclinic critical layers. ZVI has not been seen in previous studies of flows in rotating, shearing boxes because those calculations frequently lacked vertical density stratification and/or sufficient numerical resolution. Although we do not expect appreciable angular momentum transport from ZVI in the small domains in this study, we hypothesize that ZVI in larger domains with compressible equations may lead to angular transport via spiral density waves.

Fate of the Amazon River dissolved organic matter in the tropical Atlantic Ocean

Abstract: Constraining the fate of dissolved organic matter (DOM) delivered by rivers is a key to understand the global carbon cycle, since DOM mineralization directly influences air-sea CO2 exchange and multiple biogeochemical processes The Amazon River exports large amounts of DOM, and yet the fate of this material in the ocean remains unclear Here we investigate the molecular composition and transformations of DOM in the Amazon River-ocean continuum using ultrahigh resolution mass spectrometry and geochemical and biological tracers We show that there is a strong gradient in source and composition of DOM along the continuum, and that dilution of riverine DOM in the ocean is the dominant pattern of variability in the system Alterations in DOM composition are observed in the plume associated with the addition of new organic compounds by phytoplankton and with bacterial and photochemical transformations The relative importance of each of these drivers varies spatially and is modulated by seasonal variations in river discharge and ocean circulation We further show that a large fraction (50–76%) of the Amazon River DOM is surprisingly stable in the coastal ocean This results in a globally significant river plume with a strong terrigenous signature and in substantial export of terrestrially derived organic carbon from the continental margin, where it can be entrained in the large-scale circulation and potentially contribute to the long-term storage of terrigenous production and to the recalcitrant carbon pool found in the deep ocean

Hope and Healing in Urban Education: How Urban Activists and Teachers are Reclaiming Matters of the Heart

Abstract: Hope and Healing in Urban Education proposes a new movement of healing justice to repair the damage done by the erosion of hope resulting from structural violence in urban communities. Drawing on ethnographic case studies from around the country, this book chronicles how teacher activists employ healing strategies in stressed schools and community organizations, and work to reverse negative impacts on academic achievement and civic engagement, supporting their students to become powerful civic actors. The book argues that healing a community is a form of political action, and emphasizes the need to place healing and hope at the center of our educational and political strategies. At once a bold, revealing, and nuanced look at troubled urban communities as well as the teacher activists and community members working to reverse the damage done by generations of oppression, Hope and Healing in Urban Education examines how social change can be enacted from within to restore a sense of hope to besieged communities and counteract the effects of poverty, violence, and hopelessness.

Unveiling pseudospin and angular momentum in photonic graphene

Abstract: Pseudospin, an additional degree of freedom inherent in graphene, plays a key role in understanding many fundamental phenomena such as the anomalous quantum Hall effect, electron chirality and Klein paradox. Unlike the electron spin, the pseudospin was traditionally considered as an unmeasurable quantity, immune to Stern-Gerlach-type experiments. Recently, however, it has been suggested that graphene pseudospin is a real angular momentum that might manifest itself as an observable quantity, but so far direct tests of such a momentum remained unfruitful. Here, by selective excitation of two sublattices of an artificial photonic graphene, we demonstrate pseudospin-mediated vortex generation and topological charge flipping in otherwise uniform optical beams with Bloch momentum traversing through the Dirac points. Corroborated by numerical solutions of the linear massless Dirac-Weyl equation, we show that pseudospin can turn into orbital angular momentum completely, thus upholding the belief that pseudospin is not merely for theoretical elegance but rather physically measurable.

Sediment Pore Waters

Abstract: Dissolved organic matter (DOM) in marine sediment pore waters plays an important role in sediment carbon and nitrogen remineralization and may also be involved in sediment carbon preservation. In this chapter we examine this topic, focusing on: the composition and reactivity of pore water DOM, with particular reference to its role in sediment organic matter remineralization; the factors that control pore water DOM concentrations over various time and space scales; the role of benthic DOM fluxes in the oceanic cycles of carbon and nitrogen; and role of pore water DOM in sediment carbon preservation. Approaches to modeling pore water DOM are also described.

Stellar diameters and temperatures - VI. High angular resolution measurements of the transiting exoplanet host stars HD 189733 and HD 209458 and implications for models of cool dwarfs

Abstract: We present direct radii measurements of the well-known transiting exoplanet host stars HD 189733 and HD 209458 using the CHARA Array interferometer. We find the limbdarkened angular diameters to be θLD = 0.3848 ± 0.0055 and 0.2254 ± 0.0072 mas for HD 189733 and HD 209458, respectively. HD 189733 and HD 209458 are currently the only two transiting exoplanet systems where detection of the respective planetary companion’s orbital motion from high-resolution spectroscopy has revealed absolute masses for both star and planet. We use our new measurements together with the orbital information from radial velocity and photometric time series data, Hipparcos distances, and newly measured bolometric fluxes to determine the stellar effective temperatures (Teff = 4875 ± 43, 6092 ± 103K), stellar linearradii(R∗ =0.805 ±0.016,1.203 ±0.061R� ),meanstellardensities(ρ∗ =1.62 ±0.11, 0.58 ± 0.14 ρ� ), planetary radii (Rp = 1.216 ± 0.024, 1.451 ± 0.074 RJup), and mean planetary densities (ρp = 0.605 ± 0.029, 0.196 ± 0.033 ρJup) for HD 189733b and HD 209458b, respectively. The stellar parameters for HD 209458, an F9 dwarf, are consistent with indirect estimates derived from spectroscopic and evolutionary modelling. However, we find that models are unable to reproduce the observational results for the K2 dwarf, HD 189733. We show that, for stellar evolutionary models to match the observed stellar properties of HD 189733, adjustments lowering the solar-calibrated mixing-length parameter to αMLT =1.34 need to be

Heterogeneity of long-history migration explains cultural differences in reports of emotional expressivity and the functions of smiles

Abstract: A small number of facial expressions may be universal in that they are produced by the same basic affective states and recognized as such throughout the world. However, other aspects of emotionally expressive behavior vary widely across culture. Just why do they vary? We propose that some cultural differences in expressive behavior are determined by historical heterogeneity, or the extent to which a country’s present-day population descended from migration from numerous vs. few source countries over a period of 500 y. Our reanalysis of data on cultural rules for displaying emotion from 32 countries [n = 5,340; Matsumoto D, Yoo S, Fontaine J (2008) J Cross Cult Psychol 39(1):55–74] reveals that historical heterogeneity explains substantial, unique variance in the degree to which individuals believe that emotions should be openly expressed. We also report an original study of the underlying states that people believe are signified by a smile. Cluster analysis applied to data from nine countries (n = 726), including Canada, France, Germany, India, Indonesia, Israel, Japan, New Zealand, and the United States, reveals that countries group into “cultures of smiling” determined by historical heterogeneity. Factor analysis shows that smiles sort into three social-functional subtypes: pleasure, affiliative, and dominance. The relative importance of these smile subtypes varies as a function of historical heterogeneity. These findings thus highlight the power of social-historical factors to explain cross-cultural variation in emotional expression and smile behavior.

Imperfect drug penetration leads to spatial monotherapy and rapid evolution of multidrug resistance

Abstract: Infections with rapidly evolving pathogens are often treated using combinations of drugs with different mechanisms of action. One of the major goal of combination therapy is to reduce the risk of drug resistance emerging during a patient's treatment. Although this strategy generally has significant benefits over monotherapy, it may also select for multidrug-resistant strains, particularly during long-term treatment for chronic infections. Infections with these strains present an important clinical and public health problem. Complicating this issue, for many antimicrobial treatment regimes, individual drugs have imperfect penetration throughout the body, so there may be regions where only one drug reaches an effective concentration. Here we propose that mismatched drug coverage can greatly speed up the evolution of multidrug resistance by allowing mutations to accumulate in a stepwise fashion. We develop a mathematical model of within-host pathogen evolution under spatially heterogeneous drug coverage and demonstrate that even very small single-drug compartments lead to dramatically higher resistance risk. We find that it is often better to use drug combinations with matched penetration profiles, although there may be a trade-off between preventing eventual treatment failure due to resistance in this way and temporarily reducing pathogen levels systemically. Our results show that drugs with the most extensive distribution are likely to be the most vulnerable to resistance. We conclude that optimal combination treatments should be designed to prevent this spatial effective monotherapy. These results are widely applicable to diverse microbial infections including viruses, bacteria, and parasites.