Alkali barnyardgrass [Echinochloa crus-galli var. zelayensis (Kunth) Hitchc] and junglerice [Echinochloa colona (L.) Link] are problematic annual weeds in direct-seeded rice (Oryza sativa L.) fields in China. The emergence ecology of the two weed species may differ in response to environmental factors. Laboratory and screenhouse experiments were conducted to evaluate the effects of light, burial depth, mulching with wheat (Triticum aestivum L.) residue, and time and depth of flooding on the emergence of the two weed species collected from Nanjing, China. Light strongly increased seed germination. Under dark conditions, E. crus-galli seed germination (85%) was higher than that of E. colona (70%). The seeds of both species exhibited the greatest germination (90% for E. crus-galli and 80% for E. colona) when sown on the soil surface, and emergence decreased with increasing soil burial depth. Burial depths of 2.2 and 1.4 cm reduced seedling emergence by 50% for E. crus-galli and E. colona, respectively. No emergence was found at a depth of 6 cm. The seedling emergence for E. colona was lower than for E. crus-galli at the same soil burial depth. Mulching with wheat residue considerably reduced the seedling emergence and aboveground biomass of both species. The inhibitory effect of mulching with wheat residue on E. colona was more notable than on E. crus-galli. Early and deep flooding significantly suppressed the emergence, height, and biomass of E. crus-galli and E. colona, especially E. colona. The results gained from this study could provide fundamental ecological knowledge for managing Echinochloa species in direct-seeded rice systems.

The visual system of domestic poultry evolved in natural light environments, which differ in many respects from the artificial light provided in poultry houses. Current lighting systems are designed mainly around human vision and poultry production, ignoring the requirements of poultry vision and the functional development of visual abilities during rearing. A poor correlation between the light provided and that required for effective vision may influence visually mediated behaviours such as feeding and social interaction, leading to distress and poor welfare. To understand fully the impact of the light environment on the behaviour and welfare of domestic poultry we need (i) to measure the physical properties of the light environment in a standard and relevant manner; (ii) to identify the limits of visual abilities in various light environments; (iii) to determine how light environments during rearing may disrupt the functional development of vision; and (iv) to resolve how visual abilities and lighting interact to affect visually mediated behaviour. Some conclusions can be drawn about the impact of current lighting regimes on bird welfare but there remains a pressing need to resolve various issues in this interaction. We propose, first, that dark periods should have a minimum duration of six hours; second, that bright light should be used in cases where pecking damage and cannibalism do not pose a problem; and third, that it is unlikely that the 100 Hz flicker associated with fluorescent light can be perceived by poultry. With less certainty, we can suggest that ultraviolet-supplemented lighting may have some welfare benefits, and that very dim lighting may adversely affect ocular development. We can only speculate on other issues, such as preferences and motivations for different coloured lighting or the ways in which lighting affects recognition of conspecifics. Several organisations and authorities have issued guidelines for poultry house lighting that strive to safeguard welfare and that are consistent with our current, but limited, understanding. One omission is a standard system for measuring light levels in poultry houses. Illumination with natural daylight would be an ideal solution to many lighting problems. Although some systems require artificial lighting for production purposes, we argue that it may be possible to rear birds humanely in artificial environments that contain some features of natural light. These features should be those for which poultry show some motivation, or whose exclusion would damage visual development.

Leg problems are highly prevalent in modern broiler production and provision of environmental enrichment could be a strategy to improve leg health. Different types of environmental enrichment have undergone evaluation. Our objective was to conduct a systematic review of the effect of environmental enrichment on leg health in broiler chickens. The evaluation of leg health included measures of the entire leg and foot, and behavioural, pathological and physical measures. Six types of environmental enrichment were selected for inclusion: light programme, intensity of light, stocking density, perches, straw bales and separation of resources. For each type, a systematic literature search was performed. The review included 62 studies; 56 randomised trials and six cross-sectional studies. An assessment of the methodological quality of all 56 randomised trials was performed with some reporting deficits regarding occurrence of blinding, randomisation and reliability of measures. Provision of perches and increased intensity of light only displayed limited effectiveness in improving leg health and both mainly affected contact dermatitis. In contrast, there was evidence that a lowered stocking density and a dark/light schedule could improve leg health. Few studies have been carried out on the effect of straw bales and separation of resources. The few studies done have, however, shown that both types of enrichment can be effective in improving leg health. In conclusion, identifying and providing the optimal types of enrichment for broilers will reduce leg problems and increase mobility, thereby improving the welfare of the birds.

Microphytobenthos (MPB) communities are responsible for most primary production in shallow intertidal mudflats. The effects of short-term changes in temperature and light (1200, 500 and 0 μmol photons m−2 s−1) on the photosynthetic activity of intertidal MPB communities of Browns River, Tasmania, during winter (0, 5, 10 and 15°C) and summer (20, 25, 30, 35 and 40°C) were examined using a Pulse Amplitude Modulated (Water PAM) fluorometer. The MPB communities were primarily dominated by the diatom genera Navicula, Cocconeis and Amphora, with a difference in species dominance during seasons. During summer, Amphora coffeaeformis dominated communities were significantly impacted by temperatures above 30°C regardless of light intensities. The MPB was able to photosynthesize at temperatures only up to 25°C. The rETRmax at 25°C, ranged from 39.18 ± 3.42 (500 μmol photons m−2 s−1) to 22.83 ± 1.05 (0 μmol photons m−2 s−1), which was lower than the values recorded at an equivalent irradiance in in-situ summer. However, if ambient temperature exceeds 25°C in summer, it is likely that the photosynthetic capabilities of the MPB will be diminished and it will cause irreversible photoinhibition.

This essay addresses challenges that emerged during Advent through recent experience of lecturing at Berkeley Divinity School, the Episcopal Seminary at Yale. For many of my students, Advent 2020 presented particular challenges since they found that the recurring utilization of ‘darkness’ as a metaphor for sin and death did not sit easily with their commitment to anti-racist thought and practice. This essay does not attempt to provide a definitive model for how Anglicans might engage fully with Advent themes, but serves as a paper to ‘think with’ in which the author (a) engages with Michael Battle’s work on Anglican spirituality and (b) describes how her own expertise on Gregory of Nyssa was brought to bear on present needs. The Advent focus on darkness and light, I propose, does not need to be circumvented but provides Anglicans who are attentive to the problems of racism with an opportunity to examine further their own approach to ‘darkness’.

There is increasing evidence that glioblastoma, a highly aggressive brain tumour, originates from a neural stem cell (NSC) located in the subventricular zone (SVZ) of the lateral cerebral ventricle. Using the most advanced in vivo imaging techniques, Gengatharan and colleagues recently identified a day/night difference in the adult SVZ-NSC division. They reported that the circadian melatonin rhythm and its receptor control the day/night difference in NSC division with high mitotic activity during the day and low activity at night. Expression of melatonin and its receptor diminishes during ageing, which eliminates the regulatory effect of melatonin on NSC mitosis. Moreover, the circadian melatonin rhythm is dampened by light-at-night with the potential of altering the circadian mitotic cycle of NSC in the SVZ. Also, men with a lower melatonin amplitude than women exhibit a 60% higher rate of glioblastoma incidence. Given that ageing contributes significantly to glioblastoma initiation and progression, we suggest that the decline in circadian melatonin synthesis and release as well as its receptors in the SVZ, which also diminish with an ageing act in concert with other factors to facilitate glioblastoma initiation and growth.

In this paper, a light-controlled frequency reconfigurable antenna is presented for 5 G, WLAN, and radio altimeter applications. The given (44 × 28) mm2 antenna consists of a radiating V-shaped structure and three stub arrangements. The main λ/2 length stub is used to feed the antenna and the two λ/4, λ/8 length open-circuited stubs are located perpendicular to the main feeding stub for tuning the frequency of the antenna. The length of the stubs can be adjusted by placing (4 × 1.2) mm photodiode switches on the perpendicular stubs. Four experiments are carried out to analyze the performance of the antenna. When light and DC bias voltage is not applied (Experiment-1) to the photodiodes the proposed antenna radiates from 4.1 to 4.63 GHz with 12% bandwidth. When light is applied to the photodiode without DC bias voltage and DC bias voltage is applied without light (Experiment-2,3) the antenna reconfigures its frequency band from 3.43 to 3.6GHz and 4.8 to 5.4 GHz with 4.85% and 12% bandwidth respectively. The antenna shifts the radiation from 4.8 to 5.5 GHz with 14% bandwidth when the light and DC bias voltage is applied to the antenna(Experiment-4). The measured gain of the proposed antenna is greater than 3.8dBi in all the experiments.

World-renowned for having made a totally new kind of theatre, director-designer Robert Wilson first astonished international audiences in Paris in 1971 with Le Regard du sourd (Deafman Glance) and then with his twenty-four-hour Ouverture at the first edition of the Festival d’Automne in 1972. He also refers in this Conversation to Einstein on the Beach, premiered at the Avignon Festival in 1976, as another example among more of France offering him a home before he eventually founded the Watermill Center in 1992 on Long Island in the State of New York. Watermill, a laboratory for multidisciplinary creativity, opened its doors to the public in 2006 and is a focal point of the Conversation as a whole. Wilson’s immediately pre-Covid-pandemic production of The Messiah by Mozart was premiered at the Mozartwoche Salzburg in February 2020 and performed subsequently in Paris during a brief Covid ‘lull’ in September of that year. Discussion of this pivotal work leads to reflections on the opera productions that he had staged not so long before it, emphasizing the elements fundamental to his compositions – light, time, space, architecture, and silence. The Conversation, followed by audience questions addressed to Wilson, took place live online and on Facebook on 4 December 2020 as a prelude to the Festival Internacional Santiago a Mil in Chile, which opened on 3 January 2021. This was the Festival’s twenty-eighth year, but in a significantly restricted form due to Covid-19. A sequel to the Santiago interchange, also online but this time located in Paris, occurred on 17 September 2021. It resumes dialogue mainly on the Watermill Center’s broader cultural and social goals in the present and for the future, noting as well Wilson’s then current activities in Paris: a heavy schedule of four productions from the beginning of September to the end of December 2021, and a sound installation planned for 2022.

Maria Shevtsova gratefully thanks the Fundación Teatro a Mil and its General Director Carmen Romero for their initiative in inviting Robert Wilson with her to converse publicly as part of the Festival a Mil, and for permission to edit the transcript for publication in New Theatre Quarterly. Thanks are due to interpreters Margit Schmohl and Jorge Ramirez, and to Maria Luisa Vergara for organizing the audience participation included below, as well as to Alfonso Arenas, former Coordinator of the Education and Communities Area at the Theatre Foundation a Mil. Warmest gratitude is extended to Robert Wilson for his generosity in all sorts of ways, and not least for finding the time to continue the Conversation in Paris. Thanks for their kind support to Nuria Moreno, Production at Teatro Real Madrid, Christof Belka, Executive Director of RW Work Ltd, Clifford Allen, Director of Archives of the Watermill Center, and Leesa Kelly and Noah Khoshbin, curators of the 2021 outdoor exhibition Minneapolis Protest Murals at the Crossroads Summer Festival held at the Watermill Center. The exhibition presented 190 public artworks from the 900 boards of the Minneapolis Protest Murals which were created organically in Minneapolis following the murder of George Floyd on 25 May 2020. Special thanks for their gift of images are given to photographers Lucie Jansch, Javier del Real, Kristian Kruuser and Kaupo Kikkas, Lovik Delger Ostenrik, and Martyna Szczesna. Kunsang Kelden and Maria Shevtsova transcribed this Conversation in two parts. Shevtsova, Editor of New Theatre Quarterly and author of Robert Wilson (Routledge, 2007; updated edition, 2019) edited and annotated the combined transcript for publication.

Sumatran fleabane [Conyza sumatrensis (Retz.) Walker] is an emerging weed in the Australian cropping region. Populations resistant to glyphosate have evolved in Australia, creating the demand for information regarding the seed germination ecology of glyphosate-resistant (R) and glyphosate-susceptible (S) populations of C. sumatrensis. A study was conducted to examine the effects of temperature, light intensity, salt stress, osmotic stress, and burial depth on the germination and emergence of two populations (R and S) of C. sumatrensis. Both populations were able to germinate over a wide range of alternating day/night temperatures (15/5 to 35/25 C). In light/dark conditions, the R population had higher germination than the S population at 20/10 and 35/25 C. In the dark, the R population had higher germination than the S population at 25/15 C. In the dark, germination was inhibited at 30/20 C and above. Averaged over populations, seed germination of C. sumatrensis was reduced by 97% at zero light intensity (completely dark conditions) compared with full light intensity. Seed germination of C. sumatrensis was reduced by 17% and 85% at osmotic potentials of −0.4, and −0.8 MPa, respectively, compared with the control treatment. The R population had lower germination (57%) than the S population (72%) at a sodium chloride concentration of 80 mM. Seed germination was highest on the soil surface and emergence was reduced by 87% and 90% at burial depths of 0.5 and 1.0 cm, respectively. Knowledge gained from this study suggests that a shallow-tillage operation to bury weed seeds in conventional tillage systems and retention of high residue cover on the soil surface in zero-till systems may inhibit the germination of C. sumatrensis. This study also warrants that the R population may have a greater risk of invasion over a greater part of a year due to germination over a broader temperature range.

Sweet acacia [Vachellia farnesiana (L.) Willd.] is a problematic thorny weed species in several parts of Australia. Knowledge of its seed biology could help to formulate weed management decisions for this and similar species. Experiments were conducted to determine the effect of hot water (scarification), alternating temperatures, light, salt stress, and water stress on seed germination of two populations of V. farnesiana and to evaluate the response of its young seedlings (the most sensitive developmental stage) to commonly available postemergence herbicides in Australia. Both populations responded similarly to all the environmental factors and herbicides; therefore, data were pooled over the populations. Seeds immersed in hot water at 90 C for 10 min provided the highest germination (88%), demonstrating physical dormancy in this species. Seeds germinated at a wide range of alternating day/night temperatures from 20/10 C (35%) to 35/25 C (90%), but no seeds germinated at 15/5 C. Germination was not affected by light, suggesting that seeds are nonphotoblastic and can germinate under a plant canopy or when buried in soil. Germination was not affected by sodium chloride (NaCl) concentrations up to 20 mM, and about 50% of seeds could germinate at 160 mM NaCl, suggesting high salt tolerance ability. Germination was only 13% at −0.2 MPa osmotic potential, and no seeds germinated at −0.4 MPa, suggesting that V. farnesiana seeds may remain ungerminated until moisture conditions have become conducive for germination. A number of postemergence herbicides, including 2,4-D + picloram, glufosinate, paraquat, and saflufenacil, provided >85% control of biomass of young seedlings compared with the non-treated control treatment. Knowledge gained from this study will help to predict the potential spread of V. farnesiana in other areas and help to integrate herbicide use with other management strategies.

Navua sedge [Cyperus aromaticus (Ridl.) Mattf. & Kuek.], is a hard to control C4 perennial weed species in tropical regions of Australia. Knowledge of its seed biology could help to develop integrated weed management programs for this species. This study was conducted under laboratory and screenhouse conditions to evaluate the effect of alternating day/night temperatures, light, pretreatment high temperatures, burial depth, and flooding depth on the germination and emergence of two populations (Ingham and Tablelands) of C. aromaticus. Both populations germinated at temperatures ranging from 20/10 to 35/25 C; however, the Ingham population germination (76%) was greater than the Tablelands population (42%) at the highest temperature regime (35/25 C). None of the populations germinated at 15/5 C. Darkness completely inhibited germination in both populations, suggesting that the seeds are positively photoblastic. Seeds (dry and wet) of both populations germinated after exposure to pretreatment temperatures of up to 100 C for 5 min. After pretreatment at 150 C, only the Ingham population germinated, and germination was greater for dry seeds (62%) than for wet seeds (1%). Neither population germinated after exposure to 200 C. For both populations, maximum germination was observed for seeds at 0 cm; a burial depth of 0.5 cm completely inhibited emergence of the Tablelands population, and a burial depth of 2.0 cm completely inhibited germination of the Ingham population. A flooding depth of 10 cm greatly reduced emergence in both populations compared with 0 cm (62% and 78%) but 12% to 14% of seedlings still emerged, suggesting the need to integrate flooding with other management tools. The results also suggest that the Ingham population may have a greater potential to spread into new areas or become more invasive than the Tablelands population. Knowledge gained from this study can be used to manage C. aromaticus by fire/burning, tillage, and flooding.