Seasonal Shoot-Feeding by \u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae) in Michigan

Seasonal shoot-feeding by Tomicus piniperda (L.) was monitored at 2­ week intervals on 15 Scotch pine, Pinus sylvestris L., trees from 8 April through 16 November 1994 in southern Michigan. All shoots that showed evidence of T. piniperda attack were removed every two weeks. In 1994, initial spring flight of T. piniperda began on 22 March. At least two live T. piniperda adults were found on the 15 trees on each sampling date from 8 April through 1 November 1994. In addition, at least one freshly attacked, beetle- free shoot was found on each sampling date except for 1 November. The greatest numbers of newly attacked shoots, with or without adults present, were found from mid-June through mid-August. All adults found in April and May were likely parent adults, while those from June onward were primarily brood adults. Therefore, at all times of the year, live T. piniperda adults can be found on live pine trees, either feeding in the shoots or overwintering at the base of the trunk. Implications of these findings are provided in light of the US federal quarantine on T. piniperda

Possible attenuation of the G2 DNA damage cell cycle checkpoint in HeLa cells by extremely low frequency (ELF) electromagnetic fields

BACKGROUND: The issue remains unresolved as to whether low frequency magnetic fields can affect cell behaviour, with the possibility that they may be in part responsible for the increased incidence of leukaemia in parts of the population exposed to them. METHODS: Combined treatment of HeLa cells with gamma-irradiation (1, 3 and 5 Grays) and extra low frequency magnetic fields of ~50 Hz was carried out under rigorously controlled conditions. RESULTS: Synchronised cells progressing from S-phase arrived at mitosis on average marginally ahead of irradiation controls not exposed to ELF. In no instance out of a total of twenty separate experiments did this "double-insult" further delay entry of cells into mitosis, as had been anticipated. CONCLUSION: This apparently "non-genotoxic" agent (ELF) appears to be capable of affecting cells that would normally arrest for longer in G2, suggesting a weakening of the stringency of the late cycle (G2) checkpoint

The Influence of Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino-s-triazine) on the Severity of Gibberella zeae-Induced Seedling Blight of Corn

Three corn inbreds were grown in artificially inoculated, steamed greenhouse soil amended with atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) to determine the herbicide\u27s effect on the severity of Gibberella zeae (Schwabe) Petch-induced seedling blight. Corn inbreds used were Gibberella-resistant (FR632), Gibberella-intermediate (FRMo17), and Gibberella-susceptible (C123HT). Soils were amended with atrazine at rates of 2, 15, and 30 ppm. Susceptible inbred seedlings showed no response to the herbicide with symptims equally severe in controls and all 3 concentrations of atrazine. Intermediate inbred seedlings grown in all atrazine amended soils showed significantly more severe disease symptoms than controls. Soil amended with 15 ppm atrazine produced the most severely infected plants with 30 and 2 ppm showing less severe symptoms respectively. Resistant inbred seedlings showed significantly less severe symptoms than controls when grown in soils amended with 15 and 30 ppm atrazine, while soil amended with 2 ppm produced seedlings with symptoms significantly more severe than those in the control

The Influence of Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino-s-triazine) on the Severity of Gibberella zeae-Induced Seedling Blight of Corn

Three corn inbreds were grown in artificially inoculated, steamed greenhouse soil amended with atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) to determine the herbicide\u27s effect on the severity of Gibberella zeae (Schwabe) Petch-induced seedling blight. Corn inbreds used were Gibberella-resistant (FR632), Gibberella-intermediate (FRMo17), and Gibberella-susceptible (C123HT). Soils were amended with atrazine at rates of 2, 15, and 30 ppm. Susceptible inbred seedlings showed no response to the herbicide with symptims equally severe in controls and all 3 concentrations of atrazine. Intermediate inbred seedlings grown in all atrazine amended soils showed significantly more severe disease symptoms than controls. Soil amended with 15 ppm atrazine produced the most severely infected plants with 30 and 2 ppm showing less severe symptoms respectively. Resistant inbred seedlings showed significantly less severe symptoms than controls when grown in soils amended with 15 and 30 ppm atrazine, while soil amended with 2 ppm produced seedlings with symptoms significantly more severe than those in the control

A Typology of Antipassives, With Special Reference to Mayan.

Ph.D. Thesis. University of Hawaiʻi at Mānoa 2017

The Remarkable Mid-Infrared Jet of Massive Young Stellar Object G35.20-0.74

The young massive stellar object G35.20-0.74 was observed in the mid-infrared using T-ReCS on Gemini South. Previous observations have shown that the near infrared emission has a fan-like morphology that is consistent with emission from the northern lobe of a bipolar radio jet known to be associated with this source. Mid-infrared observations presented in this paper show a monopolar jet-like morphology as well, and it is argued that the mid-infrared emission observed is dominated by thermal continuum emission from dust. The mid-infrared emission nearest the central stellar source is believed to be directly heated dust on the walls of the outflow cavity. The hydroxyl, water, and methanol masers associated with G35.20-0.74 are spatially located along these mid-infrared cavity walls. Narrow jet or outflow cavities such as this may also be the locations of the linear distribution of methanol masers that are found associated with massive young stellar objects. The fact that G35.20-0.74 has mid-infrared emission that is dominated by the outflow, rather than disk emission, is a caution to those that consider mid-infrared emission from young stellar objects as only coming from circumstellar disks.Comment: Accepted for publication in ApJ Letters; 4 pages; 2 figures; a version with full resolution images is available here: http://www.ctio.noao.edu/~debuizer