Dust aerosol is an important atmospheric component due to its ice nucleating ability, which affects cloud phase and precipitation. Arizona Test Dust (ATD) is often used as a proxy for environmental dust aerosol in laboratory studies. In this work, we examine how the ice nucleating behavior of ATD is altered with different solution phase and dry aging processes under several conditions. We find that ATD ice nucleating ability is degraded in significant ways under most conditions, including aging for less than a day in deionized water or NaCl solution. Additional studies are detailed for processing in acidic solutions, salt solutions, peroxide treatment, heat treatment, and protease enzyme treatment. We find evidence of warm-temperature ice nucleating particles that share the analytically characteristic attributes of organic ice nucleators but are heat stable beyond the normal range for organic materials. We hypothesize that this is due to binding and stabilization of organic materials at the mineral surface.

BackgroundTobacco companies are offering cigarettes with ‘concept’ descriptor names that suggest sensation and/or flavour properties (eg, Marlboro ‘Velvet Fusion’). Little has been known about the identities and levels of flavour chemicals in such cigarettes.MethodsThirty-three filter cigarette variants from 27 packs (including two sampler packs with four variations each) from Canada and Mexico were analysed (rod + filter) for 177 flavour chemicals plus triacetin, a filter plasticiser and possible flavourant. Five brands of US mentholated filter cigarettes were also analysed.ResultsTwenty-seven of the 33 cigarettes (all were Mexican variants) were categorised as ‘menthol-plus’: significant menthol (3.0–11.9 mg/cigarette), plus varying amounts (0.32–3.4 mg/cigarette) of total other flavour chemicals (TOFCs) (excludes triacetin). For 10 of the 27, TOFCs >1.0 mg/cigarette. For 7 of the 27, the TOFCs profile was categorised as containing total fruit flavour compounds (TFFCs) >1.0 mg/cigarette. One Mexican variant was categorised as ‘menthol-only’ (TOFCs ≤0.15 mg/cigarette). All menthol-plus and menthol-only cigarettes contained one or two optional-crush capsules in their filters (crushed prior to analysis). All five Canadian brand variants were ‘non-flavoured’. All five US brand variants were ‘menthol-only’.ConclusionsAll but one of the ‘concept’ descriptor cigarettes from Mexico were ‘menthol-plus’. While the Canadian cigarettes complied with Canada’s flavour chemical ban, concept descriptors on the packs may increase appeal. Given the scale of the problem posed by menthol alone, health officials seeking to decrease the appeal of smoked tobacco should examine the extent to which ‘concept descriptor’ cigarettes using ‘menthol-plus’ flavour profiling together with artful descriptors are furthering the problem of smoked tobacco.

In electronic cigarettes (“electronic nicotine delivery systems”, ENDS), mixtures of propylene glycol (PG) and/or glycerol (GL; aka “vegetable glycerin”, VG) with nicotine are vaporized to create a nicotine-containing aerosol. For a given composition, the temperature required to boil the liquid at 1 atmosphere must be at least somewhat greater than the boiling point (BP). The use of ENDS is increasing rapidly worldwide, yet the BP characteristics of the PG + GL system have been characterized as the mixtures; here we re-do this, but significantly, also study the effects of added water and nicotine. BP values at 1 atmosphere pressure were measured over the full binary composition range. Fits based on the Gibbs–Konovalov theorem provide BP as a function of composition (by mole-percent, by weight-percent, and by volume-percent). BPs of PG + GL mixtures were then tested in the presence of additives such as water (2.5 and 5 mol% added) and nicotine (3 mol%). Water was found to decrease the BP of PG + GL mixtures significantly at all compositions tested, and nicotine was found to decrease the BP of PG + GL mixtures containing ~75 GL: 25 PG (by moles) or more. The effect of added water (5, 10, and 15 mol% added) on electronic cigarette degradation production (some aldehydes and formaldehyde hemiacetals) was examined and found to have no significant impact on solvent (PG or GL) degradation for the particular device used.

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Incubation length and hatching asynchrony are integral elements of the evolved reproductive strategies of birds. We examined intra- and interpopulation variation in both traits for Eastern Kingbird (Tyrannus tyrannus) populations from New York (NY), Kansas (KS), and Oregon (OR) and found that both incubation length and hatching asynchrony were not repeatable among females, after controlling for a repeatable trait, clutch size. Instead, incubation length and clutch size were influenced by ambient temperature and precipitation. Incubation length exhibited the same median (15 days) and range (13–17 days) at all sites. Model selection results indicated that incubation periods for the smallest and largest clutches were longer in NY than KS when rain was frequent throughout incubation, in replacement nests, and likely when ambient temperatures were low during egg-laying. Full hatching usually required 2 days (but up to 3), with synchronous hatching associated with small clutch sizes, short incubation periods, frequent rain during the egg-laying period, and low ambient temperatures during the first half of incubation. Nestling starvation was uncommon (5–9% of nestlings monitored) and not associated with greater hatching asynchrony. These results indicate that while clutch size, a repeatable female trait, contributed to variation in incubation length and hatching asynchrony in Eastern Kingbirds, weather was a greater source of variation, especially for incubation length.

Background The rapidly advancing corn breeding field calls for high-throughput methods to phenotype corn kernel traits to estimate yield and to study their genetic inheritance. Most of the existing methods are reliant on sophisticated setup, expertise in statistical models and programming skills for image capturing and analysis. Results We demonstrated a portable, easily accessible, affordable, panoramic imaging capturing system called Corn360, followed by image analysis using freely available software, to characterize total kernel count and different patterned kernel counts of a corn ear. The software we used did not require programming skills and utilized Artificial Intelligence to train a model and to segment the images of mixed patterned corn ears. For homogeneously patterned corn ears, our results showed accuracies of 93.7% of total kernel count compared to manual counting. Our method allowed to save an average of 3 min 40 s per image. For mixed patterned corn ears, our results showed accuracies of 84.8% or 61.8% of segmented kernel counts. Our method has the potential to greatly decrease counting time per image as the number of images increases. We also demonstrated a case of using Corn360 to count different categories of kernels on a mixed patterned corn ear resulting from a cross of sweet corn and sticky corn and showed that starch:sweet:sticky segregated in a 9:4:3 ratio in its F2 population. Conclusions The panoramic Corn360 approach enables for a portable low-cost high-throughput kernel quantification. This includes total kernel quantification and quantification of different patterned kernels. This can allow for quick estimate of yield component and for categorization of different patterned kernels to study the inheritance of genes controlling color and texture. We demonstrated that using the samples resulting from a sweet × sticky cross, the starchiness, sweetness and stickiness in this case were controlled by two genes with epistatic effects. Our achieved results indicate Corn360 can be used to effectively quantify corn kernels in a portable and cost-efficient way that is easily accessible with or without programming skills.

Silphium integrifolium is a novel perennial crop being developed for oilseed and biofuel in the midwestern US. One of the primary pests in this system is Eucosma giganteana (Lepidoptera: Tortricidae). Little is known about the chemical ecology or flight behavior of E. giganteana, but many semiochemicals have been identified from other closely related Eucosma species. Some of these compounds include: (Z)- and (E)-8-dodecenyl acetate, (E)-9-dodecenyl acetate, (Z)-8-dodecenol, (E,E)-8,10-dodecadienyl acetate, and (Z,E)-9,12-tetradecadienyl acetate. The goals of this study were to evaluate whether any of these compounds could improve capture of E. giganteana on clear sticky cards in the field, and the most attractive volatiles might affect flight behavior on a computer-automated flight mill assay. We found that there was significant attraction to (E)-8-dodecenyl acetate in two years in the field, which may possibly be a component in the pheromone blend for E. giganteana. On flight mills, E. giganteana flew an average of 23 km in a 24 h period. The presence of attractive stimuli (e.g., (E)-8-dodecenyl acetate) had arresting properties and decreasing flight distance on the mill by 78 to 80%. The longest flight distances were registered in the morning (4:00–12:00) and were 1.8-fold greater than flight distances and durations at night (20:00–4:00). (E)-8-dodecenyl acetate may be useful in behaviorally based monitoring and management strategies for E. giganteana. Overall, our research expands the knowledge on the chemical ecology of adult E. giganteana.

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