Bidirectional phonon emission in two-dimensional heterostructures triggered by ultrafast charge transfer.

Photoinduced charge transfer in van der Waals heterostructures occurs on the 100 fs timescale despite weak interlayer coupling and momentum mismatch. However, little is understood about the microscopic mechanism behind this ultrafast process and the role of the lattice in mediating it. Here, using femtosecond electron diffraction, we directly visualize lattice dynamics in photoexcited heterostructures of WSe2/WS2 monolayers. Following the selective excitation of WSe2, we measure the concurrent heating of both WSe2 and WS2 on a picosecond timescale-an observation that is not explained by phonon transport across the interface. Using first-principles calculations, we identify a fast channel involving an electronic state hybridized across the heterostructure, enabling phonon-assisted interlayer transfer of photoexcited electrons. Phonons are emitted in both layers on the femtosecond timescale via this channel, consistent with the simultaneous lattice heating observed experimentally. Taken together, our work indicates strong electron-phonon coupling via layer-hybridized electronic states-a novel route to control energy transport across atomic junctions.

Identification of the Highly Active, Species Cross-Reactive Complex I Inhibitor BAY-179.

Mitochondria are key regulators of energy supply and cell death. Generation of ATP within mitochondria occurs through oxidative phosphorylation (OXPHOS), a process which utilizes the four complexes (complex I-IV) of the electron transport chain and ATP synthase. Certain oncogenic mutations (e.g., LKB1 or mIDH) can further enhance the reliance of cancer cells on OXPHOS for their energetic requirements, rendering cells sensitive to complex I inhibition and highlighting the potential value of complex I as a therapeutic target. Herein, we describe the discovery of a potent, selective, and species cross-reactive complex I inhibitor. A high-throughput screen of the Bayer compound library followed by hit triaging and initial hit-to-lead activities led to a lead structure which was further optimized in a comprehensive lead optimization campaign. Focusing on balancing potency and metabolic stability, this program resulted in the identification of BAY-179, an excellent in vivo suitable tool with which to probe the biological relevance of complex I inhibition in cancer indications.

Back squat velocity to assess neuromuscular status of rugby league players following a match.

OBJECTIVES: Back squat mean concentric velocity (MV) and countermovement jump (CMJ) performance were examined in sub-elite rugby league players post-match to monitor changes in neuromuscular status (NMS) from baseline. Relationships between changes in back squat MV and CMJ performance variables were used to compare back squat MV to an established method to monitor NMS. DESIGN: Longitudinal observational design. METHODS: 18 male sub-elite rugby league players (mean±SD, 20.5±2.4 yr; 180.0±6.7cm; 93.3±11.2kg) performed 3 repetitions of CMJ and back squat with an individualised, pre-determined load at -2h (baseline), +30min, +24h, and +48h in relation to a match. Back squat MV, CMJ height, CMJ peak power, and CMJ peak velocity were measured with a linear position transducer. RESULTS: Significant (p<0.05), small to large decreases (ES=0.52-1.24) were observed in back squat MV up to +48h post-match. Significant (p<0.05), small to moderate decreases (ES=0.52-0.70) in CMJ height were also observed up to +24h post-match, returning to baseline at +48h. CMJ peak power and peak velocity post-match changes were not significant compared to baseline (p>0.05). Significant positive correlations were found between changes in back squat MV and CMJ height at +30min (r=0.59; p=0.009) and +48h (r=0.51; p=0.03). CONCLUSIONS: These findings suggest back squat MV may be a suitable alternative or addition to CMJ testing for monitoring NMS in rugby league players.

Short and long course neoadjuvant therapy compared for management of locally advanced rectal cancer: 11 years' experience at a regional centre.

BACKGROUND: Rectal cancer treatment outcomes for socioeconomically disadvantaged and regional patients have been suggested to be suboptimal in Australia. We investigate outcomes at a regional tertiary centre in order to determine the prognostic impact of patient and treatment factors. METHODS: Patients who underwent short and long course neoadjuvant therapy followed by surgery for stage II-III rectal cancer over an 11-year period were identified. Results were analysed to determine oncological and surgical outcomes along with whether patient and treatment-related variables were prognostic. Accessibility/Remoteness Index of Australia (ARIA) and Index of Relative Socioeconomic Disadvantage (IRSD) was used to determine remoteness and socioeconomic status, respectively. RESULTS: A total of 207 patients underwent short (n = 103, 49.8%) and long course (n = 104, 50.2%) over the time period; 81.6% (n = 169) were from outer regional, remote or very remote communities and 55.1% travelled >200 km for treatment; 57.0% were in the most disadvantaged three IRSD deciles. Five-year cancer-specific survival, recurrence-free survival and local recurrence were 83.1% (n = 172), 76.3% (n = 158) and 7.3% (n = 15), respectively. Wound complications were higher in outer regional, remote or very remote patients (25.4% versus 13.2%, P = 0.03). Remoteness, socioeconomic indices, distance to treatment and neoadjuvant type were not prognostic for any other oncological or surgical outcomes on univariate or multivariate analysis. CONCLUSIONS: Despite demography suggesting geographic and socioeconomic barriers, oncological and surgical outcomes at our regional centre were comparable to international and Australian trials. Further, these factors were not prognostic. Geographically remote patient's may safely have neoadjuvant modality individualized without compromising care.

How soon after quitting smoking does risk of heart attack decline?

A population-based case-control study (involving 1282 cases and 2068 controls) was conducted to examine the risk of myocardial infarction or coronary death after cigarette smokers quit smoking. The odds ratios for current smokers were significantly elevated compared to non-smokers (OR = 2.7 for men and OR = 4.7 for women). For ex-smokers odds ratios declined rapidly after quitting and after about 3 years they were not significantly different from unity. Fibrinogen concentrations measured in the controls only were higher in current smokers and ex-smokers up to 2 years after quitting than in non-smokers and after that time were similar to levels in non-smokers; however, most of the differences among categories of smokers were not statistically significant. These results support the hypothesis that risk of a coronary event in ex-smokers declines rapidly after quitting and within 2-3 years is similar to the risk for non-smokers.

Seasons, temperature and coronary disease.

Using data from a community-based register of heart disease (the WHO MONICA Project) associations between daily temperature, rainfall and other seasonal effects were investigated in relation to fatal coronary events and non-fatal definite myocardial infarctions in an Australian population. Coronary events, both fatal and non-fatal, were 20-40% more likely to occur in winter and spring than at other times of the year. Coronary deaths were more likely to occur on days of low temperature (and to a much lesser extent, on days of high temperature). No differences were found between patterns of sudden and non-sudden deaths (those occurring later after the onset of symptoms) associated with weather conditions. Statistical models allowing simultaneously for longer-term seasonal effects and daily temperature effects suggested that both exist. These results suggest that avoiding temperature stress could lead to reductions in the annual peaks in coronary events.

Cigarette smoking and drug use in schoolchildren: III--evaluation of a smoking prevention education programme.

A one year randomized controlled trial was used to evaluate the effectiveness of a smoking prevention programme designed by health educationalists for 10-12 year old primary schoolchildren. The study was carried out in the Hunter Region of New South Wales, Australia, using a sample of over 6000 children which would be large enough to detect, with high probability, differences of about 5% in smoking prevalence between the treatment and control groups. We report the results from the children surveyed in 1979 and 1980, before and after the programme was implemented. It was found that there were no significant differences in smoking behaviour between treatment and control groups. The changes that the programme did bring about were very small compared with the overall increases in smoking prevalence which occurred during the study period. The programme's effectiveness varied with both the age and sex of the children. It was most successful among older girls, aged 11-12 years, for whom smoking prevalence rates increased from 10.7% in 1979 to 22.6% in 1980 in the treatment group compared with 6.2% to 26.8% in the control group. It was least successful for younger boys, aged 10-11 years, for whom smoking increased from 9.4% to 14.5% in the treatment group compared with 10.3% to 11.8% in the control group. Attitudes changed in parallel with changes in smoking behaviour. Changes in knowledge differed only slightly between treatment and control groups. Inadequate implementation of the programme by some teachers may have been associated with adverse effects on the children's behaviour, attitudes and knowledge.

Cigarette smoking and drug use in schoolchildren: IV--factors associated with changes in smoking behaviour.

Factors associated with changes in the smoking behaviour of approximately 6000 schoolchildren (two cohorts aged between 10 and 12 years in 1979) over 12 months are described. They were measured twice as part of a randomized controlled trial of a smoking prevention programme. Four groups were defined: (a) those who became smokers (adopters); (b) those who remained non-smokers; (c) those who became non-smokers (quitters), and, (d) those who remained smokers. Personal and social variables were ordered using a logistic regression model according to the strength of their association with adopting and quitting smoking. Factors distinguishing adopters from children who remained nonsmokers were, being a member of the older cohort, having friends who smoke, having siblings who smoke, approving of cigarette advertising and having a relatively large amount of money to spend each week. Factors distinguishing quitters from children who continued to smoke were, having siblings who do not smoke, being a member of the younger cohort, disapproving of cigarette advertising and having a relatively small amount of money to spend each week. Initial attitude scores were indicative of future smoking behaviour and where smoking behaviour changed, attitudes also changed so that the two remained congruent. The younger cohort improved their knowledge of smoking hazards over the year irrespective of their smoking behaviour. The older cohort showed significant differences in knowledge which were dependent upon smoking category, with 1980 smokers having lower knowledge scores than non-smokers and showing an apparent decrement in their previous knowledge.

Seedling disease in an annual legume: consequences for seedling mortality, plant size, and population seed production.

The effect of seed and seedling mortality on plant population dynamics depends on the degree to which the growth and reproduction of surviving individuals can compensate for the deaths that occur. To explore this issue, we sowed seeds of the annual Kummerowia stipulacea at three densities in sunken pots in the field, which contained either field soil, microwaved field soil, or microwaved field soil augmented with oospores of three Pythium species. High sowing density reduced seedling establishment and seedling size, but these effects were independent of the soil treatment. In the oospore-augmented soil, seed and seedling survival was low. The surviving plants were initially smaller but, at maturity, average plant size was greatest in the oospore-augmented soil, compared to the other treatments. Total population seed production was unaffected by soil treatment, suggesting that the effect of disease was limited to the seedling stage, with surviving plants released from intraspecific competition. To test the hypothesis that the surviving plants in the oospore-augmented soil were more disease-resistant, seeds from each of the sowing density-soil type treatments were sown in a growth chamber inoculation study. No evidence for selection for resistance was found. A second inoculation experiment revealed that oospore inoculum reduced plant numbers and mass regardless of whether field or microwaved soil was used, suggesting that results from the field experiment were not dependent on the use of microwaved soil. The findings of this study indicate that the ecological effects of disease on individual plants and on plant populations are not necessarily equivalent.

Competition and stability in plant mixtures in the presence of disease.

A deterministic mathematical model is developed for competition between two plant species (or genotypes) in the presence of a host-specific pathogen capable of attacking one of the species only. The complexity of the plant-plant-pathogen interaction precluded precise mathematical description of all possible long-term outcomes. However, extensive computer simulation shows that stability is not an inevitable consequence of the differential interaction, rather, the outcome depends greatly upon the growth rates and relative competitive abilities of the plant species and on the transmission efficiency of the pathogen and its effect on individual host plants. The model confirmed the general validity of previous intuitive arguments but clearly indicated that the occurrence of inflected yield curves is not a sufficient indication in itself of long-term stability.

Barley Yellow Dwarf Disease in Natural Populations of Dominant Tallgrass Prairie Species in Kansas.

The grasses Sorghastrum nutans (Indian grass), Schizachyrium scoparium (little bluestem), Panicum virgatum (switchgrass), and Andropogon gerardii (big bluestem) are four of the most common plant species present in a tallgrass prairie (1). Infection with barley yellow dwarf virus (BYDV, family Luteoviridae) is of interest in these species because of the potential effects of the virus on tallgrass prairie plant communities and the potential for tallgrass prairie to function as a reservoir of the virus for infection in wheat or barley fields. In a previous inoculation experiment, an unidentified strain of BYDV transmitted by the aphid species Rhopalosiphum padi was reported to infect S. scoparium but none of the other three grass species (2). We sampled for the presence of five virus strains in at least 50 blooming plants of each grass species in a natural tallgrass prairie stand in August 2000. Samples were collected in watersheds that were designated 1B, 1D, K1A, 20B, and 20C at Konza Prairie Biological Station in the Flint Hills near Manhattan, KS. To detect the virus, we used enzyme-linked immunosorbent assay (ELISA) with antibodies purchased from Agdia (Elkhart, IN). For the PAV, MAV, RMV, and SGV strains, we used double-antibody sandwich ELISA with alkaline phosphatase label. For Cereal yellow dwarf virus (RPV), we used compound direct ELISA with alkaline phosphatase label. The scoring of ELISA results was based on comparison with infected and uninfected control plants of the same species. Symptoms of infection in the field were difficult to interpret visually, since plants in this natural environment often showed multiple symptoms of stress. None of the five strains were detected in 51 individuals of S. nutans. For 50 individuals of S. scoparium, the incidence of infection by the different strains was 4% for MAV, 0% for PAV, 2% for RMV, 0% for RPV, and 58% for SGV. For 51 individuals of P. virgatum, the incidence of infection was 31% for MAV, 0% for PAV, 0% for RMV, 0% for RPV, and 4% for SGV. For 64 individuals of A. gerardii, the incidence of infection was 59% for MAV, 0% for PAV, 0% for RMV, 0% for RPV, and 3% for SGV. The impact of BYDV on these tallgrass prairie species remains to be determined. The PAV strain is the most commonly reported strain in wheat in Kansas but was not recovered from these grass species. References: (1) C. C. Freeman. The flora of Konza Prairie: A historical review and contemporary patterns. Pages 69-80 in: Grassland Dynamics. A. K. Knapp et al., eds. Oxford, 1998. (2) W. N. Stoner. Plant Dis. Rep. 60:593, 1976.

Methodological issues in interpreting trends in MONICA event rates.

Before looking at the trends in coronary event rates and case fatality rates in the WHO MONICA Project, it is necessary to assess the consistency and validity of the data. In the Newcastle MONICA Collaborating Centre, two methods have been used. One involves monitoring data quality by comparisons with external data systems such as hospital discharge data and official mortality records. The other is to examine the internal consistency of MONICA diagnostic findings. For fatal myocardial infarction (MI) or coronary death, there is consistent evidence of a decline, but the MONICA data are not adequate to assess relative changes in sudden compared to non-sudden death rates. For non-fatal definite MI there was an increase early in the study, possibly due to a change in methods, but rates have now stabilized. For non-fatal possible MI there has been a steady increase in rates for events which may be becoming less severe. This is consistent with increasing hospital admissions for subacute ischaemic heart disease (IHD) and angina. This paper exemplifies the importance of maintaining internal and external surveillance of the quality of the data.

Success of cardiopulmonary resuscitation after heart attack in hospital and outside hospital.

OBJECTIVES: To determine factors associated with cardiopulmonary resuscitation being attempted after cardiac arrest from myocardial infarction, in or outside hospital, and estimate short term and long term survival rates. DESIGN: Descriptive cross sectional and cohort study. SETTING: Community based register of all suspected heart attacks and sudden cardiac deaths in Lower Hunter region of New South Wales, Australia. SUBJECTS: 4924 men and women aged 25-69. MAIN OUTCOME MEASURES: Rates of attempted cardiopulmonary resuscitation and survival after successful resuscitation. RESULTS: Cardiopulmonary resuscitation was attempted in 41% of cases of cardiac arrest after myocardial infarction outside hospital and 63% of cases in hospital. Survival rates at 28 days were 12% and 39% respectively. Among the survivors, although 41% had another myocardial infarction (or coronary death), 81% of both groups were still alive two years later. Younger and better educated people were more likely to receive cardiopulmonary resuscitation in either setting, and being married predicted cardiopulmonary resuscitation being attempted outside hospital. Younger age predicted better survival rates after attempted resuscitation in hospital. CONCLUSIONS: The reasons for better education to predict cardiopulmonary resuscitation being attempted need explanation. The higher survival rate after cardiopulmonary resuscitation in hospital compared with outside hospital and the good long term prognosis for survivors in both settings suggest that attempts to improve success of cardiopulmonary resuscitation outside hospital may be worth while.

Evolution of resistance and virulence in plant-herbivore and plant-pathogen interactions.

Herbivores and pathogens often attack or infect the same plant parts, and the same plant traits can affect the likelihood and degree of damage. Research on plant-herbivore and plant-pathogen interactions in natural systems have, however, proceeded largely independently of each other. Our understanding of both types of plant-enemy interaction would be enhanced by greater exposure of researchers to developments in both disciplines and by more studies of interactions between pathogen and herbivore species associated with the same hosts.

A Bayesian approach to the inference of diploid genotypes using haploid genotypes.

Morris and Spieth (1978) described a method of calculating unbiased estimates of diploid genotype frequencies given information on the genotypes of haploid cells derived from diploid individuals. They concluded that three haploids per diploid would minimize sampling variance of genotype frequencies, given a fixed total number of haploids examined. If the identity of individual diploid genotypes is needed, Morris and Spieth (1978) stated that more haploids should be collected per diploid. We extend this work by showing from a Bayesian perspective that the probability of misclassification of individuals depends not only on the number of haploids sampled, but also on the genetic structure of the population since misclassification error will increase as the frequency of heterozygotes increases. Since information on the genetic structure (allele frequencies, inbreeding coefficient) of a population is rarely known prior to the initiation of an empirical study, the usefulness of our Bayesian approach is in experimental design, by revealing the magnitude of possible misclassification errors given a particular choice of number of haploids.

Passive smoking and the risk of heart attack or coronary death.

OBJECTIVES: To estimate the prevalence of passive smoking in an Australian population, the magnitude of risk of myocardial infarction or coronary death associated with passive smoking and the extent to which fibrinogen concentrations might be affected by passive smoking. DESIGN: A population-based case-control study of myocardial infarction or coronary death and passive smoking, and measurement of fibrinogen in a random sample from the same population. SETTING AND PARTICIPANTS: Residents of the Lower Hunter Region of New South Wales aged 35-69 years in 1988-1989. Case subjects were all those who suffered myocardial infarction or coronary death. Control subjects were participants in a risk factor prevalence survey. OUTCOME MEASURES: Myocardial infarction or coronary death, defined by criteria of the WHO MONICA Project, and fibrinogen concentration (measured in controls only). RESULTS: Prevalence of passive smoking at home was 20% for male case subjects, 13% for male control subjects, 29% for female case subjects and 19% for female control subjects. The corresponding prevalence rates for passive smoking at work were 40%, 44%, 41% and 37%. Odds ratios of myocardial infarction or coronary death for active smokers compared with non-smokers were 4.70 (95% confidence interval [CI], 3.35-6.58) in women and 2.71 (95% CI, 2.07-3.53) in men. For women the odds ratios of myocardial infarction or coronary death for those exposed to passive smoking at home were 2.46 (95% CI, 1.47-4.13) among non-smokers and 1.48 (95% CI, 0.67-3.30) among ex-smokers. For men the odds ratios for passive smoking at home were 0.97 (95% CI, 0.50-1.86) for non-smokers and 1.78 (95% CI, 1.13-2.79) for ex-smokers. The odds ratios for passive smoking at work did not suggest increased risk. Fibrinogen concentrations were generally higher among people exposed to passive smoking at home or work compared with those not exposed but were not as high as concentrations in active smokers. CONCLUSIONS: Passive smoking increases the risk of coronary heart disease and increased fibrinogen concentration provides a marker of its effect.

Seed size variation and predation of seeds produced by wild and crop-wild sunflowers.

The movement of pollen between crop and wild sunflowers (both Helianthus annuus) has led to concerns about the possible introduction of crop transgenes into wild populations. The persistence of crop traits in wild populations will depend in part on the relative fitness of crop-wild hybrid vs. wild plants. Using seeds from two large experimental field plots, we found that seeds produced by crop-wild plants were twice the size of wild seeds and differed in coloration. Head diameter, date of flowering, identity of mother plant, and levels of predispersal predation explained some variation in mean seed size. We hypothesized that postdispersal vertebrate seed predation would be affected by seed size, with hybrid seeds preferentially eaten. In each of three field trials, significantly more hybrid seeds were eaten (62% of hybrid seed; 42% of wild seed). Within the category of wild seeds, larger seeds were preferentially eaten; however among hybrid seeds, predation was not significantly related to seed size. In this study, differential predation thus reduces hybrid fitness and would presumably slow the spread of transgenes into wild populations.

Trends in ischaemic heart disease in the Hunter Region of New South Wales 1985-1989.

OBJECTIVE: To find out whether trends in rates of non-fatal myocardial infarction (MI) parallel trends in rates of coronary death. DESIGN: A population-based observational study involving continuous surveillance of all suspected heart attacks or coronary deaths from 1985 to 1989. STUDY POPULATION: Residents of the Hunter Region of New South Wales aged under 70 years. MAIN OUTCOME MEASURES: Rates of non-fatal definite or possible MI or fatal MI or coronary death, as defined by the diagnostic criteria of the WHO MONICA Project. RESULTS: For men, mortality rates declined by an average of 16.2 per 100,000 per year (95% confidence interval [CI]: -23.8, -8.7); rates of non-fatal definite MI declined by 16.2 per 100,000 (95% CI: -27.8, -4.6); rates of non-fatal possible MI increased initially and then stabilised. For women smaller changes occurred in the same directions. CONCLUSION: In this population trends in rates for non-fatal definite MI paralleled the declines in mortality rates. Rates for less severe non-fatal possible MI did not follow this pattern, perhaps reflecting increased medical attention to chest pain.