We present a Late Pleistocene paleoecological record from King Island in western Bass Strait, Tasmania, and compare this to existing records from the eastern Bass Strait islands to improve our understanding of the region’s paleoecology and paleoclimatology. Vegetation change across the region followed similar trajectories during the late glacial–Middle Holocene, characterized by homogeneous warming and wetting trends. Spatial divergence occurred during the Middle Holocene when sea level rose, and different drivers began influencing western and eastern Bass Strait islands. In eastern Bass Strait, Middle Holocene sea-level rise caused replacement of woodland by coastal heathland, while in the west, a drier period accompanied by fires transformed forests to forest–scrub. The comparative analysis suggests that Westerly driven climatic anti-phasing was pronounced at higher latitudes of Tasmania during the late glacial–Early Holocene. A combination of weak Leeuwin Current, positive Indian Ocean Dipole (IOD), and El Niño–Southern Oscillation (ENSO) intensification contributed to Middle Holocene aridity across Bass Strait. Strong Westerlies and negative IOD phases led to greater regionalization of rainfall across western Bass Strait during the Late Holocene, while ENSO intensification drove rainfall declines in eastern Bass Strait. These findings provide new insights into the complexity of Late Pleistocene environmental dynamics across southeast Australia.

This study examines the performance of low-cost, low-power GNSS positioning systems for glacier monitoring in high-latitude environments. We compare the positioning performance of co-located low-cost u-blox ZED-F9P GNSS units (a few hundred USDs) and survey-grade Trimble R10 units (> $10,000 USD) under stationary (on land) and dynamic (on glacier) conditions near Terra Nova Bay, Antarctica. Low-cost and survey-grade systems yield almost identical error magnitudes under short (3 m), medium (34 km) and long (390 km) baseline kinematic-positioning scenarios. We further examined the efficacy of low-cost GNSS for glaciological applications by installing four u-blox and two Trimble receivers on Priestley Glacier to observe tide-modulated ice flexure. All receivers successfully detected subtle tidal oscillations with amplitudes < 3 cm, consistent with the predicted phasing from a tide model. These experiments offer a strong rationale for the widespread use of low-cost receivers to expand and densify GNSS monitoring networks, both in Antarctica and in glaciated regions worldwide.

ABSTRACT IMPACT: Strengthening investigator and community engagement to improve human health OBJECTIVES/GOALS: Community Engagement is one of the 14 core competencies for CT research defined by the CTSA Education Core Competency Work Group. To meet this, the UMN CTSI created the Community Mentor for Scholars Program with goals to: 1) train Scholars to engage stakeholders; and 2) provide community with formal mentoring training and linkages to researchers at UMN. METHODS/STUDY POPULATION: The CM Program was implemented over 12 months and includes four components. One, Scholars were trained in stakeholder identification and working with a community mentor (CM) through two seminars presented by expert faculty and staff. Two, CMs were identified, recruited, and matched with Scholars through a collaborative effort of our CTSI Education and Community Engagement cores. Three, Scholars and CMs learned about the program from a 2-hour Kick-Off event. Four, CMs and Scholars each completed four online modules developed through an NCATS administrative supplement. Scholar-CM pairs met at least four times to plan and hold a bi-directional ‘Community Conversation’ with an audience of key stakeholders convened by the CM. The CM Program was evaluated through in-person interviews. RESULTS/ANTICIPATED RESULTS: In 2019-2020, CTSI initiated the pilot program with four KL2 Scholar - CM pairs. Two pairs did not complete the program due to time pressures, a parental leave, and the COVID-19 pandemic. Feedback from the two Scholar - CM pairs was positive, specifically:

CMs reported the training modules were useful, resulting in better understanding of CTSI research programs and increased capacity to mentor

Scholars felt the interactions with CMs positively impacted their future research

Mentors supported experiential learning, offered insight on community perspectives, and successfully facilitated community engagement principles. DISCUSSION/SIGNIFICANCE OF FINDINGS: The second cohort launched in late 2020 with inclusion of TL1 Scholars. They will be matched with CMs in spring 2021. After Cohort 2 completion, the program design and materials will be updated based on evaluation results from scholars and mentors and then will be piloted with select CTSAs before sharing across the CTSA consortium.

Comparison of numerically computed solutions to exact (analytical) time-dependent solutions, when possible, is superior to intercomparison as a technique for verification of numerical models. At least two sources of such exact solutions exist for the isothermal shallow ice-sheet equation: similarity solutions and solutions with ‘compensatory accumulation’. In this paper, we derive new similarity solutions with non-zero accumulation. We also derive exact solutions with (i) sinusoidal-in-time accumulation and (ii) basal sliding. A specific test suite based on these solutions is proposed and used to verify a standard explicit finite-difference method. This numerical scheme is shown to reliably track the position of a moving margin while being characterized by relatively large thickness errors near the margin. The difficulty of approximating the margin essentially explains the rate of global convergence of the numerical method. A transformed version of the ice-sheet equation eliminates the singularity of the margin shape and greatly accelerates the convergence. We also use an exact solution to verify an often-used numerical approximation for basal sliding and we discuss improvements of existing benchmarks.

Life on Earth spans a range of temperatures and exhibits biological growth rates that are temperature dependent. While the observation that growth rates are temperature dependent is well known, we have recently shown that the statistical distribution of specific growth rates for life on Earth is a function of temperature (Corkrey et al., 2016). The maximum rates of growth of all life have a distinct limit, even when grown under optimal conditions, and which vary predictably with temperature. We term this distribution of growth rates the biokinetic spectrum for temperature (BKST). The BKST possibly arises from a trade-off between catalytic activity and stability of enzymes involved in a rate-limiting Master Reaction System (MRS) within the cell. We develop a method to extrapolate quantile curves for the BKST to obtain the posterior probability of the maximum rate of growth of any form of life on Earth. The maximum rate curve conforms to the observed data except below 0°C and above 100°C where the predicted value may be positively biased. The deviation below 0°C may arise from the bulk properties of water, while the degradation of biomolecules may be important above 100°C. The BKST has potential application in astrobiology by providing an estimate of the maximum possible growth rate attainable by terrestrial life and perhaps life elsewhere. We suggest that the area under the maximum growth rate curve and the peak rate may be useful characteristics in considerations of habitability. The BKST can serve as a diagnostic for unusual life, such as second biogenesis or non-terrestrial life. Since the MRS must have been heavily conserved the BKST may contain evolutionary relics. The BKST can serve as a signature summarizing the nature of life in environments beyond Earth, or to characterize species arising from a second biogenesis on Earth.

In 2013, the Kenyan government adopted a hybrid censorship strategy that relied on regulation, the presence of a strong security state, and the willingness of Kenyans to self-censor. The goal of this censorship strategy was to ensure a peaceful election. This study examines two issues. First, it investigates steps taken by the Kenyan government to minimise hate speech. Second, it explores how efforts to minimise hate speech affected citizen communications over SMS during the 2013 election. An initial round of qualitative data was gathered (n = 101) through a structured exit interview administered election week. A statistically significant, representative sample of quantitative data was gathered by a reputable Kenyan polling firm (n ≥ 2000). Both sets of empirical data indicate that Kenyan citizens cooperated in large part with efforts to limit political speech. Yet speech was not always completely “peaceful’. Rather, voters used electronic media to insult, offend, and express contentious political views as well as express peace speech. This study argues that the empirical evidence suggests hate speech over text messages during the Kenyan election declined between 2008 and 2013.”

We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.

Smoking cessation interventions during routine clinical encounters by health professionals have the potential to reach smokers and facilitate cessation. Although psychologists might appear to be ideal providers of such interventions, international research suggests that their provision is limited. This paper reports the results of a survey conducted in NSW, Australia, of psychologists’ (n = 72) smoking intervention practices, attitudes, and barriers to providing such care. Less than half of the respondents reported assessing smoking status for ‘all or nearly all’ of their clients. Across a range of smoking cessation intervention types, the most frequent response given indicated provision to ‘none or almost none’ of clients who smoked. Only 13% of respondents indicated even ‘advising cessation’ to ‘all or nearly all’ of their smoking clients. Barriers included concern about negative influence on the therapeutic relationship, inadequacy of training and lack of confidence to intervene. Respondents were less likely to provide intervention for smoking than for cannabis, methamphetamine ‘ice’, and alcohol. The study suggests that the potential of Australian psychologists to assist smokers to quit is not being realised, and that there is a need to address the barriers to care provision.

Significant new opportunities for astrophysics and cosmology have been identified at low radio frequencies. The Murchison Widefield Array is the first telescope in the southern hemisphere designed specifically to explore the low-frequency astronomical sky between 80 and 300 MHz with arcminute angular resolution and high survey efficiency. The telescope will enable new advances along four key science themes, including searching for redshifted 21-cm emission from the EoR in the early Universe; Galactic and extragalactic all-sky southern hemisphere surveys; time-domain astrophysics; and solar, heliospheric, and ionospheric science and space weather. The Murchison Widefield Array is located in Western Australia at the site of the planned Square Kilometre Array (SKA) low-band telescope and is the only low-frequency SKA precursor facility. In this paper, we review the performance properties of the Murchison Widefield Array and describe its primary scientific objectives.

Objectives: The aim of this study was to estimate the relationship between the financial impact of a new drug and the recommendation for reimbursement by the Australian Pharmaceutical Benefits Advisory Committee (PBAC).

Methods: Data in the PBAC summary database were abstracted for decisions made between July 2005 and November 2009. Financial impact—the upper bound of the values presented in the PBAC summary database—was categorized as ≤A$0, >A$0 up to A$10 million, A$10 million up to A$30 million, and >A$30 million per year. Descriptive, logistic, survival, and recursive partitioning decision analyses were used to estimate the relationship between the financial impact of a new drug indication and the recommendation for reimbursement. Multivariable analyses controlled for other clinical and economic variables, including cost per quality-adjusted life-year gained.

Results: Financial impact was a significant predictor of the recommendation for reimbursement. In the logistic analysis, the odds ratios of reimbursement for drug submissions with financial impacts ≥A$10 million to ≥A$30 million or >A$0 to <A$10 million compared with ≤A$0 were 0.12 (95 percent confidence interval [CI]: 0.03–0.51) and 0.16 (95 percent CI: 0.04–0.60), respectively. In the recursive partition decision analysis, the first split of the data was for submissions with a positive financial impact compared with those with a zero or negative financial impact.

Conclusions: In Australia, financial impact on the drug budget is an important determinant of whether a new drug is recommended for reimbursement when cost-effectiveness estimates and other clinical and economic variables are controlled.

A fire-mediated recruitment bottleneck provides a possible explanation for the coexistence of trees and grasses in mesic savannas. The key element of this hypothesis is that saplings are particularly vulnerable to fire because they are small enough to be top-killed by grass fires, but unlike juveniles, they take several years to recover their original size. This limits the number of recruits into the adult size classes. Thus savanna vegetation may be maintained by a feedback whereby fire restricts the density of adult trees and allows a grass layer to develop, which provides fuel for subsequent fires. Here, we use results from a landscape-scale fire experiment in tropical Australia, to explore the possible existence of a recruitment bottleneck. This experiment compared tree recruitment and survival over 4 y under regimes of no fire, annual early and annual late dry-season fire. Stem mortality decreased with increasing stem height in the fire treatments but not in the unburnt treatment. Tree recruitment was 76–84% lower in the fire treatments than the unburnt treatment. Such fire-induced stem loss of saplings and reduced recruitment to the canopy layer in this eucalypt savanna are consistent with the predictions of the fire-mediated recruitment bottleneck hypothesis.

Highly active antiretroviral therapy (HAART) has markedly decreased morbidity and mortality in human immunodeficiency virus type 1 (HIV-1)-infected individuals in the developed world. Successful therapy often results in stable plasma levels of HIV-1 RNA below the limits of detection of commercial assays. Nonetheless, HIV-1 has not been cured by HAART. The causes of persistence of HIV infection in the face of current therapy appear to be multifactorial: latent but replication-competent provirus in resting CD4+ T cells, cryptic viral expression below the limits of detection of clinical assays, and viral sanctuary sites might all contribute to persistence. Clearance of HIV infection will almost certainly require a multimodality approach that includes potent suppression of HIV replication, therapies that reach all compartments of residual HIV replication and depletion of any reservoirs of persistent, quiescent proviral infection. This review highlights the basic mechanisms for the establishment and maintenance of viral reservoirs and pharmaceutical approaches towards their elimination.

Six rhizotrons in an Eucalyptus tetrodonta savanna revealed seasonal changes in the abundance of fine roots (≤ 5 mm diameter). Fine roots were almost completely absent from the upper 1 m of soil during the dry season, but proliferated after the onset of wet-season rains. At peak abundance of 3.9 kg m−2 soil surface, fine roots were distributed relatively uniformly throughout 1 m depth, in contrast with many tropical savannas and tropical dry forests in which fine roots are most abundant near the soil surface. After 98% of cumulative annual rainfall had been received, fine roots began to disappear rapidly, such that 76 d later, less than 5.8% of peak abundance remained. The scarcity of fine roots in the upper 1 m of soil early in the dry season suggests that evergreen trees may be able to extract water from below 1 m throughout the dry season. Persistent deep roots together with abundant fine roots in the upper 1 m of soil during the wet season constitute a ‘dual’ root system. Deep roots might buffer atmospheric CO2 against increase by sequestering carbon at depth in the soil.

Gallery and floodplain forests in monsoonal northern Australia are mostly sclerophyllous and dominated by five closely related species of Melaleuca (Myrtaceae) amongst which niche differentiation is unclear. We present a floristic and environmental analysis of ‘the flooded forest’ using data from 340 plots distributed across 450 000 km2 of the Top End of the Northern Territory. Melaleuca argentea was confined to streams and occurred on sandier substrates, whereas M. cajuputi mostly occurred in the near-coastal lowlands on clay soils. The greater basal area of M. cajuputi suggests an association with productive sites. Melaleuca dealbata, M. viridiflora and M. leucadendra occurred on a wide range of soils. More deeply floodprone sites were occupied by M. argentea and M. leucadendra along streams and by M. leucadendra and M. cajuputi on floodplains and in swamps. A general deficiency but occasional abundance of Melaleuca seedlings suggests that regeneration is episodic. Seedlings were more frequent in recently burnt areas and especially where fires had been severe. We propose that Melaleuca forests occur where disturbance by fire and/or floodwater is too great for rain forest to persist, rendering them the wetland analogue to the eucalypts that dominate well-drained portions of the north Australian environment.

Understanding the causes of savanna–forest dynamics is vital as small but widespread changes in the extent of tropical forests can have major impacts on global climate, biodiversity and human well-being. Comparison of aerial photographs for 50 rain-forest patches in Kakadu National Park had previously revealed a landscape-wide monotonic expansion of rain-forest boundaries between 1964 and 2004. Here floristic, structural, environmental and disturbance attributes of the changes were investigated by sampling 588 plots across 30 rain-forest patches. Areas that had changed from savanna to rain forest were associated with a significantly higher abundance of rain-forest trees and less grasses, relative to stable savanna areas. Ordination analyses showed that overall floristic composition was not significantly different between newly established rain forest and longer established rain forest. Generalized linear models also indicated that contemporary levels of disturbance (fire and feral animal impact) and environmental variables (slope and soil texture) were poor predictors of historical vegetation change. We concluded that (1) the rain-forest boundaries are highly dynamic at the decadal scale; (2) rain-forest expansion is consistent with having been driven by global environmental change phenomena such as increases in rainfall and atmospheric CO2; and (3) expansion will continue if current climatic trends and management conditions persist.