This paper studies a class of singular fibrations, called self-crossing boundary fibrations, which play an important role in semitoric and generalized complex geometry. These singular fibrations can be conveniently described using the language of Lie algebroids. We will show how these fibrations arise from (nonfree) torus actions, and how to use them to construct and better understand self-crossing stable generalized complex four-manifolds. We moreover show that these fibrations are compatible with taking connected sums, and use this to prove a singularity trade result between two types of singularities occurring in these types of fibrations (a so-called nodal trade).

The inaugural data from the first systematic program of sea-ice observations in Kotzebue Sound, Alaska, in 2018 coincided with the first winter in living memory when the Sound was not choked with ice. The following winter of 2018–19 was even warmer and characterized by even less ice. Here we discuss the mass balance of landfast ice near Kotzebue (Qikiqtaġruk) during these two anomalously warm winters. We use in situ observations and a 1-D thermodynamic model to address three research questions developed in partnership with an Indigenous Advisory Council. In doing so, we improve our understanding of connections between landfast ice mass balance, marine mammals and subsistence hunting. Specifically, we show: (i) ice growth stopped unusually early due to strong vertical ocean heat flux, which also likely contributed to early start to bearded seal hunting; (ii) unusually thin ice contributed to widespread surface flooding. The associated snow ice formation partly offset the reduced ice growth, but the flooding likely had a negative impact on ringed seal habitat; (iii) sea ice near Kotzebue during the winters of 2017–18 and 2018–19 was likely the thinnest since at least 1945, driven by a combination of warm air temperatures and a persistent ocean heat flux.

With over a century of records, we present a detailed analysis of the spatial and temporal occurrence of marine turtle sightings and strandings in the UK and Ireland between 1910 and 2018. Records of hard-shell turtles, including loggerhead turtles (Caretta caretta, N = 240) and Kemp's ridley turtles (Lepidochelys kempii, N = 61), have significantly increased over time. However, in the most recent years there has been a notable decrease in records. The majority of records of hard-shell turtles were juveniles and occurred in the boreal winter months when the waters are coolest in the North-east Atlantic. They generally occurred on the western aspects of the UK and Ireland highlighting a pattern of decreasing records with increasing latitude, supporting previous suggestions that juvenile turtles arrive in these waters via the North Atlantic current systems. Similarly, the majority of the strandings and sightings of leatherback turtles (Dermochelys coriacea, N = 1683) occurred on the western aspects of the UK and the entirety of Ireland's coastline. In contrast to hard-shell turtles, leatherback turtles were most commonly recorded in the boreal summer months with the majority of strandings being adult sized, of which there has been a recent decrease in annual records. The cause of the recent annual decreases in turtle strandings and sightings across all three species is unclear; however, changes to overall population abundance, prey availability, anthropogenic threats and variable reporting effort could all contribute. Our results provide a valuable reference point to assess species range modification due to climate change, identify possible evidence of anthropogenic threats and to assess the future trajectory of marine turtle populations in the North Atlantic.

Deposits of at least three glaciations are present in New Jersey and the New York City area. The oldest deposits are magnetically reversed. Pollen and stratigraphic relations suggest that they are from the earliest Laurentide advance at ~2.4 Ma. Deposits of a second advance are overlain by peat dated to 41 ka and so are pre-Marine Isotope Stage (pre-MIS) 2. Their relation to marine deposits indicates that they predate MIS 5 but postdate MIS 11 and may postdate MIS 7 or 9, suggesting an MIS 6 age. The most recent deposits are of MIS 2 (last glacial maximum [LGM]) age. Radiocarbon dates and varve counts tied to glacial-lake events indicate that LGM ice arrived at its terminus at 25 ka, stood at the terminus until ~24 ka, retreated at a rate of 80 m/yr until 23.5 ka, and then retreated at a rate of 12 m/yr to 18 ka. At 18 ka the retreat record connects to the base of the North American Varve Chronology at Newburgh, New York. The 25–24 ka age for the LGM is slightly younger than, but within the uncertainty of, cosmogenic ages; it is significantly older than the oldest dated macrofossils in postglacial deposits in the region.

This paper presents latest thinking from the Institute and Faculty of Actuaries’ Model Risk Working Party and follows on from their Phase I work, Model Risk: Daring to Open the Black Box. This is a more practical paper and presents the contributors’ experiences of model risk gained from a wide range of financial and non-financial organisations with suggestions for good practice and proven methods to reduce model risk. After a recap of the Phase I work, examples of model risk communication are given covering communication: to the Board; to the regulator; and to external stakeholders. We present a practical framework for model risk management and quantification with examples of the key actors, processes and cultural challenge. Lessons learned are then presented from other industries that make extensive use of models and include the weather forecasting, software and aerospace industries. Finally, a series of case studies in practical model risk management and mitigation are presented from the contributors’ own experiences covering primarily financial services.

Phorate {O,O-diethyl S-[(ethylthio)methyl] phosphorodithioate}, disulfoton {O,O-diethyl S-[2-(ethylthio)ethyl] phosphorodithioate}, linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], or metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] when used alone did not reduce soybean [Glycine max (L.) Merr. ‘Calland’] grain yield or plant population. However, combinations of metribuzin with either phorate or disulfoton interacted synergistically to reduce both soybean grain yield and plant population significantly even at recommended rates of both chemicals. Combinations of linuron with either phorate or disulfoton at recommended rates did not reduce soybean grain yield or plant population. Greenhouse studies further substantiated the synergistic interaction of phorate or disulfoton with metribuzin.

The dissipation of four commonly used soil-applied herbicides was examined in a standardized field experiment in three southern states (Kentucky, Mississippi, and Tennessee). Averaged over the three soils and 2 yr, the relative order of increasing half-life defined as time for 50% disappearance in days (DT50) was acetochlor (6.3 d) = alachlor (6.3 d) = SAN 582 (7.3 d) < metolachlor (13.7 d). Metolachlor was the most persistent in the soil surface, and this could potentially translate into greater duration of weed control into the growing season. All examined herbicides had a DT50 that averaged less than 14 d in all states in both years, so full-season weed control of susceptible species would not be expected. Rapid herbicide degradation was encouraged in these field sites by adequate to excessive soil moisture and warm temperatures throughout the sampling interval. The soils also were light textured, and the lower adsorption of the herbicide allowed for degradation ease and perhaps leaching below the sampling depth.

Field experiments were conducted in Princeton, KY, in 1982, 1983, and 1984 to evaluate johnsongrass [Sorghum halepense (L.) Pers. # SORHA] control programs in no-tillage, doublecropped soybeans [Glycine max (L.) Merr. ‘Essex′]. Sequential applications of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} or fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} at 0.2 kg ai/ha provided 36 to 94% johnsongrass control. The lower control values from these treatments were obtained in the droughty 1983 growing season while the higher and acceptable control ratings were obtained in 1982 and 1984 when rainfall was more plentiful. Preplant applications that contained glyphosate [N-(phosphonomethyl)glycine] provided johnsongrass control greater than those containing paraquat (1,1′-dimethyl-4,4′-bypyridinium ion). Soybean yields and soil moisture were greater with preplant applications of glyphosate than with preplant applications of paraquat or foliar applications of sethoxydim, fluazifop, or glyphosate. Greatest yields were obtained with a combination of a preplant application of glyphosate and a postemergence application of sethoxydim.

Mechanical scarification of burcucumber (Sicyos angulatus L.) seeds resulted in increased water absorption and germination. Burcucumber germination occurred at temperatures ranging from 15 to 35 C with optimum germination occurring from 20 to 30 C. Scarified burcucumber seeds were more sensitive to simulated moisture stress than were either soybean [Glycine max (L.) Merr. ‘Williams’] or corn [Zea mays L. ‘Pioneer Brand 3369A’]. Regardless of osmotic potential, intact burcucumber seeds did not germinate; scarified seeds germinated at osmotic potentials to −6 bars. Cold stratification at 4 C for 18 weeks modified seedcoat permeability so that 11% of non-scarified burcucumber seeds germinated. Increasing depth of planting decreased emergence with limited emergence occurring at depths of 15 and 16 cm in field and growth chamber studies, respectively.

Children and adolescents are a vulnerable group to develop post-traumatic stress symptoms after natural or man-made disasters. In the light of increasing numbers of refugees under the age of 18 years worldwide, there is a significant need for effective treatments. This meta-analytic review investigates specific psychosocial treatments for children and adolescents after man-made and natural disasters. In a systematic literature search using MEDLINE, EMBASE and PsycINFO, as well as hand-searching existing reviews and contacting professional associations, 36 studies were identified. Random- and mixed-effects models were applied to test for average effect sizes and moderating variables. Overall, treatments showed high effect sizes in pre–post comparisons (Hedges' g = 1.34) and medium effect sizes as compared with control conditions (Hedges' g = 0.43). Treatments investigated by at least two studies were cognitive–behavioural therapy (CBT), eye movement desensitization and reprocessing (EMDR), narrative exposure therapy for children (KIDNET) and classroom-based interventions, which showed similar effect sizes. However, studies were very heterogenic with regard to their outcomes. Effects were moderated by type of profession (higher level of training leading to higher effect sizes). A number of effective psychosocial treatments for child and adolescent survivors of disasters exist. CBT, EMDR, KIDNET and classroom-based interventions can be equally recommended. Although disasters require immediate reactions and improvisation, future studies with larger sample sizes and rigorous methodology are needed.