• The Yarlung suture mélange, Lopu Range, southern Tibet: Provenance of sandstone blocks and transition from oceanic subduction to continental collision

      Metcalf, Kathryn; Kapp, Paul; Department of Geosciences, University of Arizona, Tucson, AZ, USA (ELSEVIER SCIENCE BV, 2017-08)
      With the aim of better understanding the history of ocean closure and suturing between India and Asia, we conducted a geologic investigation of a siliciclastic matrix tectonic melange within the western Yarlung suture zone of southern Tibet (Lopu Range region, similar to 50 km northwest of Saga). The siliciclastic matrix melange includes abundant blocks of ocean plate stratigraphy and sparse blocks of sandstone. Metapelite and metabasite blocks in the melange exhibit lower greenschist fades mineral assemblages, indicating that they were not deeply subducted. We obtained detrital zircon U-Pb geochronologic and sandstone petrographic data from sandstone blocks in the melange and sandstone beds from Tethyan Himalayan strata exposed to the south of the suture. The sandstones from both units are all similar in U-Pb detrital zircon age spectra and petrography to the nearby Tethyan Cretaceous-Paleocene Sangdanlin section, which records the earliest appearance (at similar to 59 Ma) of arc-affinity strata deposited conformably on Indian-affinity strata. Two Paleocene sandstones, one of which is a schistose block incorporated in the siliciclastic matrix melange, yielded indistinguishable maximum depositional ages of similar to 59 Ma. Mesozoic Asian-affinity sandstone blocks previously documented in the siliciclastic matrix melange 200-500 km along strike to the east are notably absent in the Lopu Range region. We documented a gradational transition in structural style from the block-in-matrix melange in the northeast to the south-vergent Tethyan thrust belt in the southwest. Blocks of Tethyan Himalayan strata increase in size and the volumetric proportion of matrix decreases from northeast to southwest. We conclude that no arc-affinity sandstone blocks were incorporated into the subduction complex until India-Asia collision at similar to 59 Ma when the Xigaze forearc basin became overfilled and Tethyan Himalayan strata entered the trench. As collision progressed, there was a gradual transition in structural style from block-in-matrix melange formation to imbricate-style thrust belt formation. (C) 2017 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
    • Yaws resurgence in Bankim, Cameroon: The relative effectiveness of different means of detection in rural communities

      Boock, Alphonse Um; Awah, Paschal Kum; Mou, Ferdinand; Nichter, Mark; Univ Arizona, Sch Anthropol (PUBLIC LIBRARY SCIENCE, 2017-05-08)
      Background Yaws is an infectious, debilitating and disfiguring disease of poverty that mainly affects children in rural communities in tropical areas. In Cameroon, mass-treatment campaigns carried out in the 1950s reduced yaws to such low levels that it was presumed the disease was eradicated. In 2010, an epidemiological study in Bankim Health District detected 29 cases of yaws. Five different means of detecting yaws in clinical and community settings were initiated in Bankim over the following five years. Methodology This observational study reviews data on the number of cases of yaws identified by each of the five yaws detection approaches: 1) passive yaws detection at local clinics after staff attended Neglected Tropical Disease awareness workshops, 2) community-based case detection carried out in remote communities by hospital staff who relied on community health workers to identify cases, 3) yaws screening following mass Buruli Ulcer outreach programs being piloted in the district, 4) school-based screening programs conducted as stand-alone and follow-up activities to mass outreach events, and 5) house to house active surveillance activities conducted in thirty-eight communities. Implementation of each of the four community-based approaches was observed by a team of health social scientists tasked with assessing the strengths and limitations of each detection method. Findings Eight hundred and fifteen cases of yaws were detected between 2012 and 2015. Only 7% were detected at local clinics. Small outreach programs and household surveys detected yaws in a broad spectrum of communities. The most successful means of yaws detection, accounting for over 70% of cases identified, were mass outreach programs and school based screenings in communities where yaws was detected. Conclusion The five interventions for detecting yaws had a synergistic effect and proved to be valuable components of a yaws eradication program. Well planned, culturally sensitive mass out-reach educational programs accompanied by school-based programs proved to be particularly effective in Bankim. Including yaws detection in a Buruli Ulcer outreach program constituted a win-win situation, as the demonstration effect of yaws treatment (rapid cure) increased confidence in early Buruli ulcer treatment. Mass outreach programs functioned as magnets for both diseases as well as other kinds of chronic wounds that future outreach programs need to address.
    • Yb^3+-doped double-clad phosphate fiber for 976 nm single-frequency laser amplifiers

      Wu, Jingwei; Zhu, Xiushan; Temyanko, Valery; LaComb, L.; Kotov, Leonid; Kiersma, Kort; Zong, Jie; Li, Michael; Chavez-Pirson, Arturo; Norwood, R. A.; et al. (OPTICAL SOC AMER, 2017-03-20)
      Highly ytterbium (Yb3+)-doped double-clad phosphate fiber was fabricated for the investigation of power scaling of a 976 nm single-frequency laser. Over 3 W single-frequency laser output power was obtained with gain fibers shorter than 10 cm. Our experimental results show that Yb3+-doped phosphate fiber is a promising gain medium for 976 nm laser amplifiers. (C) 2017 Optical Society of America
    • Yearning and Its Measurement in Complicated Grief

      Robinaugh, Donald J.; Mauro, Christine; Bui, Eric; Stone, Lauren; Shah, Riva; Wang, Yuanjia; Skritskaya, Natalia A.; Reynolds, Charles F.; Zisook, Sidney; O'Connor, Mary-Frances; et al. (TAYLOR & FRANCIS INC, 2016)
      Persistent intense yearning for the deceased is a core clinical feature of complicated grief (CG) that distinguishes it from other mental disorders that develop following loss. The Yearning in Situations of Loss Scale (YSL) is a recently developed assessment of yearning. To assess the psychometric properties of the YSL in those with CG, we administered the YSL, Inventory of Complicated Grief, and Quick Inventory of Depression Symptomatology to 303 treatment-seeking bereaved adults with CG. Our results suggest the YSL is a reliable assessment with acceptable convergent and discriminant validity as a measure of yearning in those with CG.
    • Year‐Round Transpiration Dynamics Linked With Deep Soil Moisture in a Warm Desert Shrubland

      Szutu, D. J.; Papuga, S. A.; Univ Arizona, Sch Nat Resources & Environm (AMER GEOPHYSICAL UNION, 2019-07-12)
      Ecohydrological processes in semiarid shrublands and other dryland ecosystems are sensitive to discrete pulses of precipitation. Anticipated changes in the frequency and magnitude of precipitation events are expected to impact the spatial and temporal distribution of soil moisture in these drylands, thereby impacting their ecohydrological processes. Recent field studies have shown that in dryland ecosystems, transpiration dynamics and plant productivity are largely a function of deep soil moisture available after large precipitation events, regardless of where the majority of plant roots occur. However, the strength of this relationship and how and why it varies throughout the year remains unclear. We present eddy covariance, soil moisture, and sap flow measurements taken over an 18-month period in conjunction with an analysis of biweekly precipitation, shallow soil, deep soil, and stem stable water isotope samples from a creosotebush-dominated shrubland ecosystem at the Santa Rita Experimental Range in southern Arizona. Within the context of a hydrologically defined two-layer conceptual framework, our results support that transpiration is associated with the availability of deep soil moisture and that the source of this moisture varies seasonally. Therefore, changes in precipitation pulses that alter the timing and magnitude of the availability of deep soil moisture are expected to have major consequences for dryland ecosystems. Our findings offer insights that can improve the representation of drylands within regional and global models of land surface atmosphere exchange and their linkages to the hydrologic cycle.
    • Yellow snapper (Lutjanus argentiventris) connectivity in the Southern Gulf of California

      Reguera-Rouzaud, Nicole; Díaz-Viloria, Noé; Sánchez-Velasco, Laura; Flores-Morales, Ana Laura; Parés-Sierra, Alejandro; Aburto-Oropeza, Octavio; Munguía-Vega, Adrián; Univ Arizona, Sch Nat Resources & Environm, Conservat Genet Lab (SPRINGER HEIDELBERG, 2020-07-07)
      We analysed the genetic connectivity and larval transport routes ofLutjanus argentiventristo test if eddies could transport coastal-demersal fish larvae between the peninsular and mainland coasts of the Southern Gulf of California. Larval transport was estimated using the ROMS oceanographic model during the main spawning period (July-August). We used 12 microsatellite loci to assess genetic diversity, population structure and gene flow estimates in 233L. argentiventrissamples from nine sites. The oceanographic model suggested the existence of a stream flow and eddies that maintain connectivity in the Southern Gulf of California. The global AMOVA and pairedF(ST)showed no significant genetic differentiation among the sites, and the estimations of the number of migrants indicated moderate to high gene flow among locations. However, after testing five demographic scenarios of connectivity with a coalescent sampler, our results supported the presence of a metapopulation structure with source-sink dynamics. We discuss the challenges to reconcile our results considering the assumptions of the different analyses and the characteristics of marine metapopulations. Connectivity ofL. argentiventriscould be representative of other costal-demersal species with a similar life history and spawning season.
    • Young adult cancer caregivers' use of social media for social support

      Warner, Echo L; Kirchhoff, Anne C; Ellington, Lee; Waters, Austin R; Sun, Ye; Wilson, Andrew; Cloyes, Kristin G; Univ Arizona, Arizona Canc Ctr (WILEY, 2020-05-04)
      Objective To describe how young adult cancer caregivers (YACC) use social media for social support during a cancer experience. Methods Eligible YACC were 18 to 39 years, used Facebook and/or Instagram at least once per week, and cared for an adult cancer patient diagnosed 6 months to 5 years prior (N = 34). Recruitment of a cross-sectional sample occurred through oncology clinics in Utah and online advertising by caregiving and cancer organizations from September 2017 to June 2018. Semi-structured telephone interviews were recorded, transcribed, iteratively coded, and qualitatively analyzed, yielding four categories concerning how YACC use social media. Results Caregivers were most commonly spouses aged 29 years on average (range 21-38); cancer patients were 37 years (range 19-76). Analysis yielded four distinct yet related categories: Category 1: Posting about cancer on social media often begins as a strategy for YACC to efficiently provide updates about the cancer patient. Category 2: Caregivers who actively post on social media experience a variety of different functional social supports to which they otherwise would not have access. Category 3: Posting about cancer online presents an opportunity for negative consequences. Category 4: Potential for negative consequences influences how some caregivers use social media. Conclusions Supportive services, including social media-based supports, are needed for YACC in formats that are convenient for them as they balance their caretaking duties with their daily lives.
    • Young adults’ psychological and physiological reactions to the 2016 U.S. presidential election

      Hoyt, Lindsay T.; Zeiders, Katharine H.; Chaku, Natasha; Toomey, Russell B.; Nair, Rajni L.; Univ Arizona, Norton Sch Family & Consumer Sci, Dept Family Studies & Human Dev (PERGAMON-ELSEVIER SCIENCE LTD, 2018-06)
      Elections present unique opportunities to study how sociopolitical events influence individual processes. The current study examined 286 young adults' mood and diurnal cortisol responses to the 2016 U.S. presidential election in real-time: two days before the election, election night, and two days after the election of Donald Trump, with the goal of understanding whether (and the extent to which) the election influenced young adults' affective and biological states. Utilizing piecewise trajectory analyses, we observed high, and increasing, negative affect leading up to the election across all participants. Young adults who had negative perceptions of Trump's ability to fulfill the role of president and/or were part of a non-dominant social group (i.e., women, ethnic/racial minority young adults) reported increased signs of stress before the election and on election night. After the election, we observed a general "recovery" in self-reported mood; however, diurnal cortisol indicators suggested that there was an increase in biological stress among some groups. Overall, findings underscore the role of macro-level factors in individuals' health and well-being via more proximal attitudes and physiological functioning.

      Shappee, B. J.; Piro, A. L.; Holoien, T. W.-S.; Prieto, J. L.; Contreras, C.; Itagaki, K.; Burns, C. R.; Kochanek, C. S.; Stanek, K. Z.; Alper, E.; et al. (IOP PUBLISHING LTD, 2016-07-27)
      On 2014 December 9.61, the All-sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-141p just similar to 2 days after first light using a global array of 14 cm diameter telescopes. ASASSN-141p went on to become a bright supernova (V = 11.94 mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-141p for more than 100 days. We find that ASASSN-141p had a broad light curve (Delta m(15) (B) = 0.80 +/- 0.05), a B-band maximum at 2457015.82 +/- 0.03, a rise time of 16.941(-0.10)(+0.11) days, and moderate host-galaxy extinction (E (B - V)host = 0.33 +/- 0.06). Using ASASSN-141p, we derive a distance modulus for NGC 4666 of mu = 30.8 +/- 0.2, corresponding to a distance of 14.7 +/- 1.5 Mpc. However, adding ASASSN-141p to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Finally, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any nondegenerate companion larger than 0.34 RG(circle dot).
    • Young and Eccentric: The Quadruple System HD 86588

      Tokovinin, Andrei; Corbett, Hank; Fors, Octavi; Howard, Ward; Law, Nicholas M.; Moe, Maxwell; Ratzloff, Jeffrey; Walter, Frederick M.; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2018-09)
      High-resolution spectroscopy and speckle interferometry reveal the young star HD 86588 as a quadruple system with a three-tier hierarchy. The 0.'' 3 resolved binary A,B with an estimated period around 300 years contains the 8-yr pair Aa,Abc (also potentially resolvable), where Ab,Ac is a double-lined binary with equal components, for which we compute the spectroscopic orbit. Despite the short period of 2.4058 days, the orbit of Ab,Ac is eccentric (e = 0.086 +/- 0.003). It has a large inclination, but there are no eclipses; only a 4.4 mmag light modulation apparently caused by star spots on the components of this binary is detected with Evryscope. Assuming a moderate extinction of A(v) = 0.5 mag and a parallax of 5.2 mas, we find that the stars are on or close to the main sequence (age >10 Myr) and their masses are from 1 to 1.3 solar. We measure the strength of the lithium line in the visual secondary B which, together with rotation, suggests that the system is younger than 150 Myr. This object is located behind the extension of the Chamaeleon I dark cloud (which explains extinction and interstellar sodium absorption), but apparently does not belong to it. We propose a scenario where the inner orbit has recently acquired its high eccentricity through dynamical interaction with the outer two components; it is now undergoing rapid tidal circularization on a timescale of similar to 1 Myr. Alternatively, the eccentricity could be excited quasi-stationary by the outer component Aa.
    • The Young and Nearby Normal Type Ia Supernova 2018gv: UV-optical Observations and the Earliest Spectropolarimetry

      Yang, Yi; Hoeflich, Peter; Baade, Dietrich; Maund, Justyn R.; Wang, Lifan; Brown, Peter. J.; Stevance, Heloise F.; Arcavi, Iair; Burke, Jamison; Cikota, Aleksandar; et al. (IOP PUBLISHING LTD, 2020-10-09)
      The nondetection of companion stars in SN Ia progenitor systems lends support to the notion of double-degenerate systems and explosions triggered by the merging of two white dwarfs. This very asymmetric process should lead to a conspicuous polarimetric signature. By contrast, observations consistently find very low continuum polarization as the signatures from the explosion process largely dominate over the pre-explosion configuration within several days. Critical information about the interaction of the ejecta with a companion and any circumstellar matter is encoded in the early polarization spectra. In this study, we obtain spectropolarimetry of SN 2018gv with the ESO Very Large Telescope at -13.6 days relative to theB-band maximum light, or similar to 5 days after the estimated explosion-the earliest spectropolarimetric observations to date of any SN Ia. These early observations still show a low continuum polarization (less than or similar to 0.2%) and moderate line polarization (0.30% 0.04% for the prominent Siii lambda 6355 feature and 0.85% 0.04% for the high-velocity Ca component). The high degree of spherical symmetry implied by the low-line and continuum polarization at this early epoch is consistent with explosion models of delayed detonations and is inconsistent with the merger-induced explosion scenario. The dense UV and optical photometry and optical spectroscopy within the first similar to 100 days after the maximum light indicate that SN 2018gv is a normal SN Ia with similar spectrophotometric behavior to SN 2011fe.
    • Young genes are highly disordered as predicted by the preadaptation hypothesis of de novo gene birth

      Wilson, Benjamin A.; Foy, Scott G.; Neme, Rafik; Masel, Joanna; Univ Arizona, Dept Ecol & Evolutionary Biol (NATURE PUBLISHING GROUP, 2017-06)
      The phenomenon of de novo gene birth from junk DNA is surprising, because random polypeptides are expected to be toxic. There are two conflicting views about how de novo gene birth is nevertheless possible: the continuum hypothesis invokes a gradual gene birth process, whereas the preadaptation hypothesis predicts that young genes will show extreme levels of rgb(204, 0, 0);">gene-like traits. We show that intrinsic structural disorder conforms to the predictions of the preadaptation hypothesis and falsifies the continuum hypothesis, with all genes having higher levels than translated junk DNA, but young genes having the highest level of all. Results are robust to homology detection bias, to the non-independence of multiple members of the same gene family and to the false positive annotation of protein-coding genes.
    • A Young Patient with Painful Penile Lesions

      Gaeta, Christopher; Scholand, Stephen; Blakey, Brandon; Pescatore, Richard; Univ Arizona, Internal Med Infect Dis (CUREUS INC, 2019-12-16)
      Chancroid is a rare infection in the United States and many other developed countries. Infrequently identified as a cause of genital ulcer disease, chancroid’s atypical presentation has only been reported in approximately 20 cases annually in the United States since 2011. Infection with the causative organism, Haemophilus ducreyi, leads to an erythematous papule that rapidly evolves into a pustule. Infected individuals commonly have more than one ulcer about 2 cm in diameter that is typically noted as painful. The base of the ulcer is usually covered with a gray or yellow purulent exudate and bleeds when scraped. Despite a heavy focus in preclinical medical education, the notably rare chance to see and diagnose chancroid in clinical practice adds to the complicated profile of this infection’s identification and subsequent treatment. Such lack of familiarity contributes to reports of accuracy of clinical diagnosis ranging from 30% to 80%.
    • The young star cluster population of M51 with LEGUS – I. A comprehensive study of cluster formation and evolution

      Messa, M.; Adamo, A.; Östlin, G.; Calzetti, D.; Grasha, K.; Grebel, E. K.; Shabani, F.; Chandar, R.; Dale, D. A.; Dobbs, C. L.; et al. (OXFORD UNIV PRESS, 2018-01)
      Recently acquired WFC3 UV (F275W and F336W) imaging mosaics under the Legacy Extragalactic UV Survey (LEGUS), combined with archival ACS data of M51, are used to study the young star cluster (YSC) population of this interacting system. Our newly extracted source catalogue contains 2834 cluster candidates, morphologically classified to be compact and uniform in colour, for which ages, masses and extinction are derived. In this first work we study the main properties of the YSC population of the whole galaxy, considering a mass-limited sample. Both luminosity and mass functions follow a power-law shape with slope -2, but at high luminosities and masses a dearth of sources is observed. The analysis of the mass function suggests that it is best fitted by a Schechter function with slope -2 and a truncation mass at 1.00 +/- 0.12 x 10(5) M-circle dot . Through Monte Carlo simulations, we confirm this result and link the shape of the luminosity function to the presence of a truncation in the mass function. A mass limited age function analysis, between 10 and 200 Myr, suggests that the cluster population is undergoing only moderate disruption. We observe little variation in the shape of the mass function at masses above 1 x 10(4) M-circle dot over this age range. The fraction of star formation happening in the form of bound clusters in M51 is similar to 20 per cent in the age range 10-100 Myr and little variation is observed over the whole range from 1 to 200 Myr.
    • The z = 7.54 Quasar ULAS J1342+0928 Is Hosted by a Galaxy Merger

      Bañados, Eduardo; Novak, Mladen; Neeleman, Marcel; Walter, Fabian; Decarli, Roberto; Venemans, Bram P.; Mazzucchelli, Chiara; Carilli, Chris; Wang, Feige; Fan, Xiaohui; et al. (IOP PUBLISHING LTD, 2019-08-12)
      We present ALMA 0.'' 128 x 0.'' 20 (1.4 kpc x 1.0 kpc) resolution observations of the [C II] 158 mu m line and underlying dust continuum in the host galaxy of the most distant quasar currently known, ULAS J1342+0928 at z = 7.5413. Both the [C II] and continuum are detected and spatially resolved. The [C II] line is similar to 1.5 times more extended than the continuum emission, showing an elongated and complex structure of approximately 3.2 kpc x 6.4 kpc. Two separate peaks are clearly seen (greater than or similar to 6 sigma each) in three 100 km s(-1) width [C II] channel maps. The velocity field of the [C II] gas does not show evidence of a coherent rotation field but rather chaotic motion reminiscent of an ongoing merger.
    • z ∼ 2: An Epoch of Disk Assembly

      Simons, Raymond C.; Kassin, Susan A.; Weiner, Benjamin; Faber, Sandra M.; Trump, Jonathan R.; Heckman, Timothy M.; Koo, David C.; Pacifici, Camilla; Primack, Joel R.; Snyder, Gregory F.; et al. (IOP PUBLISHING LTD, 2017-06-30)
      We explore the evolution of the internal gas kinematics of star-forming galaxies from the peak of cosmic star formation at z similar to 2 to today. Measurements of galaxy rotation velocity V-rot, which quantify ordered motions, and gas velocity dispersion sigma(g), which quantify disordered motions, are adopted from the DEEP2 and SIGMA surveys. This sample covers a continuous baseline in redshift over 0.1 < z < 2.5, spanning 10 Gyr. At low redshift, nearly all sufficiently massive star-forming galaxies are rotationally supported (V-rot > sigma(g)). By z = 2, 50% and 70% of galaxies are rotationally supported at low (10(9)-10(10) M-circle dot) and high (10(10)-10(11) M-circle dot) stellar mass, respectively. For V-rot > 3 sigma(g), the percentage drops below 35% for all masses. From z = 2 to now, galaxies exhibit remarkably smooth kinematic evolution on average. All galaxies tend toward rotational support with time, and higher-mass systems reach it earlier. This is largely due to a mass-independent decline in sigma(g) by a factor of 3 since z - 2. Over the same time period, V-rot increases by a factor of 1.5 in low-mass systems but does not evolve at high mass. These trends in V-rot and sigma(g) are at a fixed stellar mass and therefore should not be interpreted as evolutionary tracks for galaxy populations. When populations are linked in time via abundance matching, sigma(g) declines as before and V-rot strongly increases with time for all galaxy populations, enhancing the evolution in V-rot sigma(g). These results indicate that z = 2 is a period of disk assembly, during which strong rotational support is only just beginning to emerge.
    • ZBP-89 negatively regulates self-renewal of liver cancer stem cells via suppression of Notch1 signaling pathway

      Wang, Nuozhou; Li, Ming-Yue; Liu, Yi; Yu, Jianqing; Ren, Jianwei; Zheng, Zhiyuan; Wang, Shanshan; Yang, Shucai; Yang, Sheng-Li; Liu, Li-Ping; et al. (ELSEVIER IRELAND LTD, 2019-12-23)
      Liver cancer stem cells (LCSCs) initiate hepatocellular carcinoma (HCC) and contribute to its recurrence and treatment resistance. Studies have suggested ZBP-89 as a candidate tumor suppressor in HCC. We explored the role of ZBP-89 in the regulation of LCSCs. This study was performed in liver tissue samples from 104 HCC patients, 2 cell lines and mouse tumor models. We demonstrated that ZBP-89 was weakly expressed in LCSCs. Patients with high expression of LCSC markers displayed reduced survivals and higher recurrence rates after curative surgical operation. The expression of ZBP-89 was predictive for decreased recurrence. LCSC markers were negatively correlated with ZBP-89 in HCC tissues and in enriched liver tumor spheres. The exogenous expression of ZBP-89 attenuated the tumor-sphere formation and secondary colony formation capabilities of LCSCs in vitro and tumorigenicity in vivo. Furthermore, the negative effect of ZBP-89 on cancer sternness was Notch1-dependent. Localized with Notch1 intracellular domain (NICD1) in the nucleus, ZBP-89 repressed the Notch1 signaling pathway by competitive binding to NICD1 with MAML1. Collectively, ZBP-89 negatively regulates HCC sternness via inhibiting the Notch1 signaling.
    • ZBTB32 restrains antibody responses to murine cytomegalovirus infections, but not other repetitive challenges

      Jash, Arijita; Zhou, You W; Gerardo, Diana K; Ripperger, Tyler J; Parikh, Bijal A; Piersma, Sytse; Jamwal, Deepa R; Kiela, Pawel R; Boon, Adrianus C M; Yokoyama, Wayne M; et al. (NATURE PUBLISHING GROUP, 2019-10-24)
      ZBTB32 is a transcription factor that is highly expressed by a subset of memory B cells and restrains the magnitude and duration of recall responses against hapten-protein conjugates. To define physiological contexts in which ZBTB32 acts, we assessed responses by Zbtb32-/- mice or bone marrow chimeras against a panel of chronic and acute challenges. Mixed bone marrow chimeras were established in which all B cells were derived from either Zbtb32-/- mice or control littermates. Chronic infection of Zbtb32-/- chimeras with murine cytomegalovirus led to nearly 20-fold higher antigen-specific IgG2b levels relative to controls by week 9 post-infection, despite similar viral loads. In contrast, IgA responses and specificities in the intestine, where memory B cells are repeatedly stimulated by commensal bacteria, were similar between Zbtb32-/- mice and control littermates. Finally, an infection and heterologous booster vaccination model revealed no role for ZBTB32 in restraining primary or recall antibody responses against influenza viruses. Thus, ZBTB32 does not limit recall responses to a number of physiological acute challenges, but does restrict antibody levels during chronic viral infections that periodically engage memory B cells. This restriction might selectively prevent recall responses against chronic infections from progressively overwhelming other antibody specificities.
    • ZBTB38 is dispensable for antibody responses

      Wong, Rachel; Bhattacharya, Deepta; Univ Arizona, Dept Immunobiol (PUBLIC LIBRARY SCIENCE, 2020-09-21)
      Members of the broad complex, tram track, bric-a-brac and zinc finger (BTB-ZF) family of transcription factors, such as BCL-6, ZBTB20, and ZBTB32, regulate antigen-specific B cell differentiation, plasma cell longevity, and the duration of antibody production. We found that ZBTB38, a different member of the BTB-ZF family that binds methylated DNA at CpG motifs, is highly expressed by germinal center B cells and plasma cells. To define the functional role of ZBTB38 in B cell responses, we generated mice conditionally deficient in this transcription factor. Germinal center B cells lacking ZBTB38 dysregulated very few genes relative to wild-type and heterozygous littermate controls. Accordingly, mice with hematopoietic-specific deletion ofZbtb38showed normal germinal center B cell numbers and antibody responses following immunization with hapten-protein conjugates. Memory B cells from these animals functioned normally in secondary recall responses. Despite expression of ZBTB38 in hematopoietic stem cells, progenitors and mature myeloid and lymphoid lineages were also present in normal numbers in mutant mice. These data demonstrate that ZBTB38 is dispensable for hematopoiesis and antibody responses. These conditional knockout mice may instead be useful in defining the functional importance of ZBTB38 in other cell types and contexts.
    • ZFOURGE: Using Composite Spectral Energy Distributions to Characterize Galaxy Populations at 1 < z < 4

      Forrest, Ben; Tran, Kim-Vy H.; Broussard, Adam; Cohn, Jonathan H.; Kennicutt, Jr., Robert C.; Papovich, Casey; Allen, Rebecca; Cowley, Michael; Glazebrook, Karl; Kacprzak, Glenn G.; et al. (IOP PUBLISHING LTD, 2018-08-20)
      We investigate the properties of galaxies as they shut off star formation over the 4 billion years surrounding peak cosmic star formation. To do this, we categorize similar to 7000 galaxies from 1 < z < 4 into 90 groups based on the shape of their spectral energy distributions (SEDs) and build composite SEDs with R similar to 50 resolution. These composite SEDs show a variety of spectral shapes and also show trends in parameters such as color, mass, star formation rate, and emission-line equivalent width. Using emission-line equivalent widths and strength of the 4000 angstrom break, D(4000), we categorize the composite SEDs into five classes: extreme emission line, star-forming, transitioning, post-starburst, and quiescent galaxies. The transitioning population of galaxies shows modest H alpha emission (EWREST similar to 40 angstrom) compared to more typical star-forming composite SEDs at log(10)(M/M-circle dot) similar to 10.5 (EWREST similar to 80 A). Together with their smaller sizes (3 kpc vs. 4 kpc) and higher Sersic indices (2.7 vs. 1.5), this indicates that morphological changes initiate before the cessation of star formation. The transitional group shows a strong increase of over 1 dex in number density from z similar to 3 to z similar to 1, similar to the growth in the quiescent population, while post-starburst galaxies become rarer at z less than or similar to 1.5. We calculate average quenching timescales of 1.6 Gyr at z similar to 1.5 and 0.9 Gyr at z similar to 2.5 and conclude that a fast-quenching mechanism producing post-starbursts dominated the quenching of galaxies at early times, while a slower process has become more common since z similar to 2.