Over the last two decades, anomalous warming events have been observed in coastal Antarctic regions. While these events have been documented in the Ross Sea sector, the Antarctic interior is believed to have been buffered from warming. In this work, we present data from lakes located near Mt. Heekin and Thanksgiving Valley (~85° S) along the Shackleton Glacier, which are believed to be the southern-most Antarctic dry valley lakes. In 2018, the lakes were characterized, repeat satellite images were examined, and lake water chemistry was measured. Our analysis shows that lake areas recently increased, and the water-soluble ion chemistry indicates a flushing of salts from periglacial soils, likely from increased glacial melt as illustrated by water isotope data. Our results show that high southern latitude ice-free areas have likely been affected by warm pulses over the past 60 years and these pulses may be quasi-synchronous throughout the Transantarctic Mountains.

The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing between the borehole and lake after entry. Models simulating melting of the ~6 m thick basal accreted ice layer imply that debris fall-out through the ~15 m water column to the lake sediments from borehole melting had little effect on the stratigraphy of surficial sediment cores.

Parent-Child interaction therapy (PCIT) has been shown to improve positive, responsive parenting and lower risk for child maltreatment (CM), including among families who are already involved in the child welfare system. However, higher risk families show higher rates of treatment attrition, limiting effectiveness. In N = 120 child welfare families randomized to PCIT, we tested behavioral and physiological markers of parent self-regulation and socio-cognitive processes assessed at pre-intervention as predictors of retention in PCIT. Results of multinomial logistic regressions indicate that parents who declined treatment displayed more negative parenting, greater perceptions of child responsibility and control in adult–child transactions, respiratory sinus arrhythmia (RSA) increases to a positive dyadic interaction task, and RSA withdrawal to a challenging, dyadic toy clean-up task. Increased odds of dropout during PCIT's child-directed interaction phase were associated with greater parent attentional bias to angry facial cues on an emotional go/no-go task. Hostile attributions about one's child predicted risk for dropout during the parent-directed interaction phase, and readiness for change scores predicted higher odds of treatment completion. Implications for intervening with child welfare-involved families are discussed along with study limitations.

Carers of people experiencing a first episode of psychosis are at an increased risk of developing their own physical and mental health problems. Psychoeducation has been found to improve carer wellbeing and reduce distress. However, few psychoeducation interventions have considered the resource constraints on mental health services and the impact that these can have on the implementation of any such interventions. The present service evaluation aimed to evaluate an abbreviated version (sole session) of a previously tested psychoeducation intervention (three sessions) that targets less adaptive illness beliefs (n = 17). Pre–post effect sizes reveal that all of the carers’ illness beliefs changed in the desired direction, with four out of the 10 illness beliefs associated with large to moderate improvements. When compared with the outcomes obtained in our evaluation of the more intensive, three-session version of the intervention, the between-group effects largely favoured the three-session version but were mostly small. Moderate to large effects in favour of the three-session version were found for two of the 10 illness beliefs. These findings support the further investigation of the sole session psychoeducation intervention as part of a randomised controlled trial.

In the USA, western Washington (WWA) and the Alaska (AK) Interior are two regions where maritime and continental climates, high latitude and cropping systems necessitate early maturing spring wheat (Triticum aestivum L.). Both regions aim to increase the production of hard spring bread wheat for human consumption to support regional agriculture and food systems. The Nordic region of Europe has a history of breeding for early maturing spring wheat and also experiences long daylengths with mixed maritime and continental climates. Nordic wheat also carries wildtype (wt) NAM-B1, an allele associated with accelerated senescence and increased grain protein and micronutrient content, at a higher frequency than global germplasm. Time to senescence, yield, protein and mineral content were evaluated on 42 accessions of Nordic hard red spring wheat containing wt NAM-B1 over 2 years on experimental stations in WWA and the AK Interior. Significant variation was found by location and accession for time to senescence, suggesting potential parental lines for breeding programmes targeting early maturity. Additionally, multiple regression analysis showed that decreased time to senescence correlated negatively with grain yield and positively with grain protein, iron and zinc content. Breeding for early maturity in these regions will need to account for this potential trade-off in yield. Nordic wt NAM-B1 accessions with early senescence yet with yields similar to regional checks are reported. Collaboration among alternative wheat regions can aid in germplasm exchange and varietal development as shown here for the early maturing trait.

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

The stable-isotopic signature of dissolved inorganic carbon (DIC) has been routinely used in temperate lake systems to investigate the biogeochemical dynamics of carbon. We studied seven perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, to ascertain how carbon cycling affects the δ13C of DIC in water columns of these systems. Unlike temperate lakes and, in fact, most polar lake systems, the permanent ice covers of these lakes eliminate physical mixing (turnover) and hence redistribution of DIC in the lakes, as well as minimize CO2 exchange with the atmosphere. These important and unique physical constraints have significant impact on carbon dynamics in the lakes, and important consequences for the δ13C distribution. The geochemistry in these lakes is influenced in varying amounts by landscape position, hydrologic input and their evolutionary history. Five of these lakes (both lobes of Lake Bonney, and Lakes Fryxell, Miers and Vanda) have surface water δ13C ratios of 0–4‰, Lake Hoare has more negative values, while Lake Joyce, the highest-elevation lake, has a much higher value (10.5‰). All of the lakes have upper- to mid-depth δ13C maxima reflecting biological uptake of 12C. Only four of the lakes (Lakes Vanda, Joyce, Hoare and Fryxell) have deep waters with negative values of δ13C, implying rigorous remineralization of 12C at depth. Lake Miers, the only lake that is not closed basin, has the smallest δ13C variation with depth, indicating that hydrologic exchange greatly influences the δ13C signal.

Winter wheat grain contaminated with jointed goatgrass joints is often discounted as much as 20% by grain buyers. A mail survey to Nebraska farmers in 1984 identified jointed goatgrass as one of the ten worst weed problems in winter wheat, but a field survey to the same area in 1986 found it in less than 1% of surveyed fields. The objective of this survey was to map the geographic distribution and severity of jointed goatgrass contaminating winter wheat grain in western Nebraska. Jointed goatgrass was found in 25, 29, and 20% of all wheat samples collected in 1990, 1991, and 1992, respectively. Nebraska counties bordering Colorado were found to have the highest percentage of wheat samples contaminated with jointed goatgrass joints, ranging from 23% in Cheyenne county in 1992 to 61% in Keith county in 1991.

The tolerance of two proso millet cultivars to atrazine preemergence and postemergence applications of bromoxynil, clopyralid, dicamba, or metsulfuron plus amine formulations of 2,4-D was studied in the field. Proso millet grain yield, test weight, seed weight, moisture content, and plant height at harvest were not affected by any of the herbicide treatments, despite some early-season injury observed in 1990.

Field studies were conducted from 1990 through 1997 to evaluate the long-term effect of 2- and 3-yr rotations on the control of downy brome, jointed goatgrass, and feral rye in winter wheat. At the completion of the study, jointed goatgrass and feral rye densities averaged 8 plants/m2 and < 0.1 plant/m2 for the 2- and 3-yr rotations, respectively. Downy brome densities averaged < 0.5 plant/m2 for both the 2- and 3-yr rotations, with no treatment differences observed. Winter annual grasses were not eradicated after two cycles of the 3-yr rotations, but weed densities were reduced 10-fold compared to densities after one cycle and more than 100-fold compared with the 2-yr rotations. Wheat grain contamination with dockage and foreign material followed a similar trend. The 3-yr rotations were economically competitive with 2-yr rotations and provided superior control of the winter annual grass weeds.

One of the unusual features of Lakes Fryxell and Hnare in Taylor Valley, southern Victoria Land, Antarctica, is their perennial ice cover. This ice cover limits gas exchange between the atmosphere and the lake water, and causesa very stable stratification of the lakes. We analyzed a series of water samples from profiles of these lakes and their tributaries for δ13C of the dissolved inorganic carbon (DIC) in order to qualify the carbon flux from the streams into the lakes, and to investigate the carbon cycling with in the lakes. Isotopic values in the uppermost waters (δ13C = +l.3‰ to 5.3‰ in Lake Hoare, +0.4‰ to +3.0‰ in Lake Fryxell) are close to the carbon-isotope values encountered in the streams feeding Lake Fryxell, but distinctively heavier than in streams feeding Lake Hoare (δ13C= — 2.3%n to 1.4%). These ratios are much heavier than ratios found in the moat that forms around the lakes injanuary February (δC = -10.1%). in the oxic photic zones of the lakes, photosynthesis clearly influences the isotopic composition, with layers of high productivity having enriched carbon-isotope signatures δ13C= +2.7‰ to +6.1‰). in both lakes, the isotopic values become lighter with depth, reaching minima of 3.2‰ and 4.0% in Lakes Fryxell and Hoare, respectively. These minima are caused by the microbial remineralization of isotopically light organic carbon. We present DIC flux calculations that help to interpret the isotopic distribution. For example, in Lake Hoare the higher utilization of CO2aq, and a substantially smaller inflow of CO2 from streams cause the heavier observed isotopic ratios. Differences in the hydrology and stream morphologies of the tributaries also greatly influence the carbon budgets of the basins.

It is difficult to quantify the mechanism(s) responsible for competition-induced yield loss using traditional experimental techniques. A technique using yield and 13C discrimination (Δ) for wheat, a C3 plant, has been developed to separate total yield loss (TYL) into yield loss due to N (YLNS) and water (YLWS) stresses. The objective of this research was to determine whether the Δ approach could be used in corn, a C4 plant, to separate TYL into YLNS and yield loss due to a combination of water and light stresses (YLWLS). The field study had a factorial design using five corn densities and five N rates and was conducted in western Nebraska in 1999 and 2000. Relationships for YLNS and YLWLS with TYL were derived from only a portion of the yield and Δ data collected in 1999 and validated based on the remaining data collected in 1999 and 2000. In 1999, 20 to 40% of TYL was due to YLWLS, whereas in 2000, a dry year, YLWLS accounted for 60 to 80% of the TYL. Results from using the Δ-based approach were consistent with analysis of variance results. For example, calculated YLWLS values were related to measured YLWLS by the equation: calculated YLWLS = 19 + 0.91 (measured YLWLS) (r 2 = 0.95; P < 0.01). The Δ approach, based on a plant's physiological response to the environment, can be used to separate and quantify competition-induced YLNS and YLWLS in corn.