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Despite the evidence that supermassive black holes (SMBHs) co-evolve with their host galaxy, and that most of the growth of these SMBHs occurs via merger-free processes, the underlying mechanisms which drive this secular co-evolution are poorly understood. We investigate the role that both strong and weak large-scale galactic bars play in mediating this relationship. Using 72,940 disc galaxies in a volume-limited sample from Galaxy Zoo DESI, we analyse the active galactic nucleus (AGN) fraction in strongly barred, weakly barred, and unbarred galaxies up to z = 0.1 over a range of stellar masses and colours. After controlling for stellar mass and colour, we find that the optically selected AGN fraction is 31.6 +/- 0.9 per cent in strongly barred galaxies, 23.3 +/- 0.8 per cent in weakly barred galaxies, and 14.2 +/- 0.6 per cent in unbarred disc galaxies. These are highly statistically robust results, strengthening the tantalising results in earlier works. Strongly barred galaxies have a higher fraction of AGNs than weakly barred galaxies, which in turn have a higher fraction than unbarred galaxies. Thus, while bars are not required in order to grow a SMBH in a disc galaxy, large-scale galactic bars appear to facilitate AGN fuelling, and the presence of a strong bar makes a disc galaxy more than twice as likely to host an AGN than an unbarred galaxy at all galaxy stellar masses and colours., Comment: 11 pages, 8 figures, accepted for publication in MNRAS

We present the first systematic investigation of supervised scaling laws outside of an ImageNet-like context - on images of galaxies. We use 840k galaxy images and over 100M annotations by Galaxy Zoo volunteers, comparable in scale to Imagenet-1K. We find that adding annotated galaxy images provides a power law improvement in performance across all architectures and all tasks, while adding trainable parameters is effective only for some (typically more subjectively challenging) tasks. We then compare the downstream performance of finetuned models pretrained on either ImageNet-12k alone vs. additionally pretrained on our galaxy images. We achieve an average relative error rate reduction of 31% across 5 downstream tasks of scientific interest. Our finetuned models are more label-efficient and, unlike their ImageNet-12k-pretrained equivalents, often achieve linear transfer performance equal to that of end-to-end finetuning. We find relatively modest additional downstream benefits from scaling model size, implying that scaling alone is not sufficient to address our domain gap, and suggest that practitioners with qualitatively different images might benefit more from in-domain adaption followed by targeted downstream labelling., Comment: 10+6 pages, 12 figures. Appendix C2 based on arxiv:2206.11927. Code, demos, documentation at https://github.com/mwalmsley/zoobot

A new technique for high resolution simultaneous isotopic analysis of $\delta^{18}\mathrm{O}$ and $\delta\mathrm{D}$ in liquid water is presented. A continuous stream flash evaporator has been designed that is able to vaporise a stream of liquid water in a continuous mode and deliver a stable and finely controlled water vapour sample to a commercially available Infra Red Cavity Ring Down Spectrometer. Injection of sub $\mu l$ amounts of the liquid water is achieved by pumping liquid water sample through a fused silica capillary and instantaneously vaporising it with a 100% efficiency in a home made oven at a temperature of $170 ^{o}$C. The system's simplicity, low power consumption and low dead volume together with the possibility for automated unattended operation, provides a solution for the calibration of laser instruments performing isotopic analysis of water vapour. Our work is mainly driven by the possibility to perform high resolution on line water isotopic analysis on Continuous Flow Analysis systems typically used to analyze the chemical composition of ice cores drilled in polar regions. In the following we describe the system's precision and stability, sensitivity to varying levels of sample size and we assess the observed memory effects. A test run with standard waters of different isotopic composition is presented, demonstrating the ability to calibrate the spectrometer's measurements on a VSMOW scale with a relatively simple and fast procedure.

A new technique for on-line high resolution isotopic analysis of liquid water, tailored for ice core studies is presented. We built an interface between a Wavelength Scanned Cavity Ring Down Spectrometer (WS-CRDS) purchased from Picarro Inc. and a Continuous Flow Analysis (CFA) system. The system offers the possibility to perform simultaneous water isotopic analysis of $\delta^{18}$O and $\delta$D on a continuous stream of liquid water as generated from a continuously melted ice rod. Injection of sub ${\mu}$l amounts of liquid water is achieved by pumping sample through a fused silica capillary and instantaneously vaporizing it with 100% efficiency in a home made oven. A calibration procedure allows for proper reporting of the data on the VSMOW--SLAP scale. Application of spectral methods yields the combined uncertainty of the system at below 0.1 permil and 0.5 permil for $\delta^{18}$O and $\delta$D, respectively. This performance is comparable to that achieved with mass spectrometry. Dispersion of the sample in the transfer lines limits the temporal resolution of the technique. By using an optimal filtering method we show how the measured profiles can be corrected for the smoothing effects resulting from the sample dispersion. Considering the significant advantages the technique offers, i.e. simultaneous measurement of $\delta^{18}$O and $\delta$D, potentially in combination with chemical components that are traditionally measured on CFA systems, notable reduction on analysis time and power consumption, we consider it as an alternative to traditional isotope ratio mass spectrometry with the possibility to be deployed for field ice core studies. We present data acquired in the field during the 2010 season as part of the NEEM deep ice core drilling project in North Greenland.

During its first year of operation (1997-98), the Kentucky Migrant Technology Project successfully implemented its model, used internal and external evaluations to inform improvement of the model, and began plans for expansion into new service areas. This evaluation report is organized around five questions that focus on the project model and its implementation, reaching the target population, service delivery, project outcomes, and evaluation to improve program effectiveness. The project seeks to develop innovative uses of technology to enhance the education of migrant students: to increase academic achievement, continuity of education, and appropriateness of educational programming for migrant students; to decrease dropout rates and increase reenrollment of dropouts; and to increase parental involvement. First-year project activities included helping teachers integrate technology into the curriculum; working on development of an Internet-based records transfer system; monitoring use of software and supplementing it as needed; and providing technology training to teachers, administrators, and migrant parents. The project focused on delivering services within 11 Kentucky school districts enrolling 1,334 migrant students. This report also discusses overcoming educator resistance to new technologies, the processes of identifying and recruiting student participants, statistical data on the services delivered, and the project's objectives and the second-year evaluation to measure progress toward them. Appendixes include a reprinted article "The Electronic Emissary: Bringing Together Students, Teachers, and Subject Matter Experts"; information on eligibility, student recruitment, and Migrant Education Program procedures; newspaper clippings; the project management plan; the project audit list; and a computer user's survey. (SV)

An exploratory study examined the past and present participation in education of 34 parents enrolled in 5 model family literacy programs in North Carolina and Kentucky. All respondents were high school dropouts. Over half had dropped out of adult basic education classes before completing a high school equivalency certificate. The study focused on respondents' stated reasons for dropping out of high school and for entering educational programs as adults. The following data were collected: (1) descriptive information collected by teachers at the family literacy sites, including demographic descriptions and respondents' stated reasons for entering the programs; (2) field notes generated during investigators' site visits; and (3) in-depth interviews with respondents. Study results showed that school dropout was not simply a function of low attendance, low grades, poor peer relations, substance abuse, and delinquent behavior, although all factors were present. Underlying causes were traced to a process of disengagement from schooling that began at the transition from elementary to middle school. The sense of alienation from schooling persisted through young adulthood and was an important factor in decisions to drop out of adult basic education programs. Parents persisted in family literacy programs because programs addressed that sense of alienation. Parents and children developed not only literacy skills but also an identification with schooling. (80 references) (YLB)

The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (~1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within approximately 5%, on average), but the MLS HCl abundances are generally larger (by 10-20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon-borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (approximately 0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraftHCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.

A unique dataset of airborne in situ observations of HCl, O3, HNO3, H2O, CO, CO2 and CH3Cl has been made in and near the tropical tropopause layer (TTL). A total of 16 profiles across the tropopause were obtained at latitudes between 10degN and 3degs from the NASA WB-57F high-altitude aircraft flying from Costa Rica. Few in situ measurements of these gases, particularly HCl and HNO3, have been reported for the TTL. The general features of the trace gas vertical profiles are consistent with the concept of the TTL as distinct from the lower troposphere and lower stratosphere. A combination of the tracer profiles and correlations with O3 is used to show that a measurable amount of stratospheric air is mixed into this region. The HCl measurements offer an important constraint on stratospheric mixing into the TTL because once the contribution from halocarbon decomposition is quantified, the remaining HCl (>60% in this study) must have a stratospheric source. Stratospheric HCl in the TTL brings with it a proportional amount of stratospheric O3. Quantifying the sources of O3 in the TTL is important because O3 is particularly effective as a greenhouse gas in the tropopause region.

In situ observations in a tropical subvisible cirrus cloud during the Costa Rica Aura Validation Experiment on 2 February 2006 show the presence of condensed-phase nitric acid. The cloud was observed near the tropopause at altitudes of 16.3-17.7 km in an extremely cold (183-191 K) and dry 5 ppm H2O) air mass. Relative humidities with respect to ice ranged from 150-250% throughout most of the cloud. Optical particle measurements indicate the presence of ice crystals as large as 90 microns in diameter. Condensed RN031H20 molar ratios observed in the cloud particles were 1-2 orders of magnitude greater than ratios observed previously in cirrus clouds at similar RN03 partial pressures. Nitric acid trihydrate saturation ratios were 10 or greater during much of the cloud encounter, indicating that RN03 may be present in the cloud particles as a stable condensate and not simply physically adsorbed on or trapped in the particles.

We show that a nighttime profile of OClO in the Arctic vortex during the winter of 2000 is overestimated, by nearly a factor of 2, using an isentropic trajectory model constrained by observed profiles of ClOx (ClO + 2 X ClOOCl) and BrO. Calculated abundances of nighttime OClO are shown to be sensitive to the abundance of BrOx (BrO + BrCl), details of the air parcel history during the most recent sunrise/sunset transitions, and the BrCl yield from the reaction BrO + ClO. Many uncertainties are considered, and the discrepancy between measured and modeled nighttime OClO appears to be robust. This discrepancy suggests that production of OClO occurs more slowly than implied by standard photochemistry. If the yield of BrCl from the reaction of BrO + ClO is increased from 7% (JPL 2002 value) to 11% (near the upper limit of the uncertainty), good agreement is found between measured and modeled nighttime OClO. This study highlights the importance of accurate knowledge of BrO + ClO reaction kinetics as well as air parcel trajectories for proper interpretation of nighttime OClO. These factors have a considerably smaller impact on the interpretation of OClO observations obtained during twilight (90(deg) <=SZA <= 92(deg)), when photolytic processes are still active.

The redistribution of HNO3 via uptake and sedimentation by cirrus cloud particles is considered an important term in the upper tropospheric budget of reactive nitrogen. Numerous cirrus cloud encounters by the NASA WB-57F high-altitude research aircraft during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) were accompanied by the observation of condensed-phase HNO3 with the NOAA chemical ionization mass spectrometer. The instrument measures HNO3 with two independent channels of detection connected to separate forward and downward facing inlets that allow a determination of the amount of HNO3 condensed on ice particles. Subtropical cirrus clouds, as indicated by the presence of ice particles, were observed coincident with condensed-phase HNO3 at temperatures of 197-224 K and pressures of 122-224 hPa. Maximum levels of condensed-phase HNO3 approached the gas-phase equivalent of 0.8 ppbv. Ice particle surface coverages as high as 1.4 # 10(exp 14) molecules/ square cm were observed. A dissociative Langmuir adsorption model, when using an empirically derived HNO3 adsorption enthalpy of -11.0 kcal/mol, effectively describes the observed molecular coverages to within a factor of 5. The percentage of total HNO3 in the condensed phase ranged from near zero to 100% in the observed cirrus clouds. With volume-weighted mean particle diameters up to 700 ?m and particle fall velocities up to 10 m/s, some observed clouds have significant potential to redistribute HNO3 in the upper troposphere.

NOy, total reactive nitrogen, and the long-lived tracer N2O, nitrous oxide, were measured by both in situ and remote sensing instruments during the Arctic winter 1999-2000 SAGE III Ozone Loss and Validation Experiment (SOLVE). The correlation function NOy:N2O observed before the winter Arctic vortex forms, which is known as NOy(sup), is an important reference relationship for conditions in the evolving vortex. NOy(sup) can, with suitable care, be used to quantify vortex denitrification by sedimentation of polar stratospheric cloud particles when NOy data is taken throughout the winter. Observed NOy values less than the reference value can be interpreted in terms of semi-permanent removal of active nitrogen by condensation and sedimentation processes. In this paper we present a segmented function representing NOy(sup) applicable over the full range of altitudes sampled during SOLVE. We also assess the range of application of this function and some of its limitations.