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Humpback whales (Megaptera novaeangliae) exhibit maternally driven fidelity to feeding grounds, and yet occasionally occupy new areas. Humpback whale sightings and mortalities in the New York Bight apex (NYBA) have been increasing over the last decade, providing an opportunity to study this phenomenon in an urban habitat. Whales in this area overlap with human activities, including busy shipping traffic leading into the Port of New York and New Jersey. The site fidelity, population composition and demographics of individual whales were analysed to better inform management in this high-risk area. Whale watching and other opportunistic data collections were used to identify 101 individual humpback whales in the NYBA from spring through autumn, 2012–2018. Although mean occurrence was low (2.5 days), mean occupancy was 37.6 days, and 31.3% of whales returned from one year to the next. Individuals compared with other regional and ocean-basin-wide photo-identification catalogues (N = 52) were primarily resighted at other sites along the US East Coast, including the Gulf of Maine feeding ground. Sightings of mother-calf pairs were rare in the NYBA, suggesting that maternally directed fidelity may not be responsible for the presence of young whales in this area. Other factors including shifts in prey species distribution or changes in population structure more broadly should be investigated.

Functionalized hydrocarbons have various ecological and industrial uses, from signaling molecules and antifungal/antibacterial agents to fuels and specialty chemicals. The potential to produce functionalized hydrocarbons using the cellulolytic, endophytic fungus, Ascocoryne sarcoides, was quantified using genome-enabled, stoichiometric modeling. In silico analysis identified available routes to produce these hydrocarbons, including both anabolic- and catabolic-associated strategies, and determined correlations between the type and size of the hydrocarbons and culturing conditions. The analysis quantified the limits of the wild-type metabolic network to produce functionalized hydrocarbons from cellulose-based substrates and identified metabolic engineering targets, including cellobiose phosphorylase (CP) and cytosolic pyruvate dehydrogenase complex (PDHcyt). CP and PDHcyt activity increased the theoretical production limits under anoxic conditions where less energy was extracted from the substrate. The incorporation of both engineering targets resulted in near-complete conservation of substrate electrons in functionalized hydrocarbons. The in silico framework was integrated with in vitro fungal batch growth experiments to support O2 limitation and functionalized hydrocarbon production predictions. The metabolic reconstruction of this endophytic filamentous fungus describes pathways for both specific and general production strategies of 161 functionalized hydrocarbons applicable to many eukaryotic hosts.

Growth in common bottlenose dolphins (Tursiops truncatus) was investigated through examination of sex-specific, ontogenetic changes in the mass of 38 discrete body compartments, utilizing stranded dolphins in good body condition (n = 145). Ontogenetic allometry and the body composition technique were used to quantitatively describe growth patterns. Although adult males were significantly larger than adult females in total body mass (TBM) and total length, overall patterns of growth were remarkably similar between sexes. The integument, locomotor muscle, and vertebral column together represented 50%–58% of TBM across all life history categories, although their relative contributions varied ontogenetically. Young dolphins invested the greatest percentage of TBM in integument, while locomotor muscle was the single largest body component in adults. In both sexes (1) most muscle groups displayed positive allometry, (2) most skeletal elements displayed negative allometric or isometric growth, (3) most abdominal viscera associated with digestion displayed positive allometry, and (4) the brain displayed negative allometric growth. Reproductive tissues exhibited the highest rates of growth in both sexes, and increased as a percentage of TBM with maturity. This study provides an integrated view of bottlenose dolphin growth and a quantitative baseline of body composition for future monitoring of this sentinel species of ecosystem health.

Several species of odontocete cetaceans depredate bait and catch and, as a result, become hooked and entangled in pelagic longline fisheries. The present study measured how selected commercial longline hooks, including “weak hooks”, behaved within odontocete mouths. Five hooks (Mustad-16/0, Mustad-18/0, Mustad J-9/0, Korean 16, and Korean 18) were tested on three species of odontocetes known to interact with longline fisheries—short-finned pilot whales (Globicephala macrorhynchus), Risso's dolphins (Grampus griseus), and false killer whales (Pseudorca crassidens). Specimens were secured to a stanchion, hooks were placed in the mouth at multiple positions along the dorsal lip, and the force required to pull each hook free was measured. The soft tissue lips of these odontocetes were capable of resisting forces up to 250 kg before failing. The polished steel M-16, M-18, and J-9 hooks straightened at forces between 50 and 225 kg, depending on hook gauge. When straightened, these hooks exposed the sharpened barb, which sliced through the lip tissue, usually releasing the hook intact. The K-16 and K-18 hooks behaved very differently, breaking at higher forces (110–250 kg) and consistently just at the barb; usually, there was measurable soft-tissue loss and often shards of the hook were retained within those soft tissues. The different behaviours of these two hook types—the M and J type polished steel vs. the K type carbon steel—were consistent across all species tested. Mechanical tests were also conducted to determine if hooks could fracture the mandible of these same odontocetes. Only the M-18 and K-18 hooks had sufficiently large gapes to hook around the mandible, and both hook types fractured bone in short-finned pilot whales and Risso's dolphins. These results support other lines of evidence indicating that longline hooks can cause serious injury to these species, and suggest possible steps to mitigate these impacts.

The fungal endophyte, Ascocoryne sarcoides, produced aviation, gasoline and diesel-relevant hydrocarbons when grown on multiple substrates including cellulose as the sole carbon source. Substrate, growth stage, culturing pH, temperature and medium composition were statistically significant factors for the type and quantity of hydrocarbons produced. Gasoline range (C_5-C_(12)), aviation range (C_8-C_(16)) and diesel range (C_9-C_(36)) organics were detected in all cultured media. Numerous non-oxygenated hydrocarbons were produced such as isopentane, 3,3-dimethyl hexane and d-limonene during exponential growth phase. Growth on cellulose at 23˚C and pH 5.8 produced the highest overall yield of fuel range organics (105 mg * g•biomass^(-1)). A change in metabolism was seen in late stationary phase from catabolism of cellulose to potential oxidation of hydrocarbons resulting in the production of more oxygenated compounds with longer carbon chain length and fewer fuel-related compounds. The results outline rational strategies for controlling the composition of the fuel-like compounds by changing culturing parameters.

The effect of aluminum on the oxidation resistance of titanium disilicide (TiSi2) was investigated. The aluminum was mixed with titanium disilicide powder, compacted and then sintered. The compacts were oxidized at elevated temperatures for various times. The oxide coatings were examined by thin film diffractometry and also in a scanning electron microscope equipped with energy dispersive spectroscopy.The oxidation of TiSi2 containing aluminum resulted in a porous, non-protective coating of mullite at temperatures of 1000°C and below. However, pre-oxidation at higher temperatures produced a more dense, protective mullite which showed adequate resistance to oxidation at the lower temperatures. Parabolic kinetics with an activation energy of 20 kcal mol−1 were observed. However, intergranular oxidation of an aluminum-rich phase resulted in the severe degradation of the material's strength. Resume L'effect de l'aluminium sur la resistance a l'oxydation du TiSi2 a ete etudie. L'aluminium est melange d...

The oxidation of titanium disilicide, TiSi2, was studied in the temperature range 800−1300°C in air. Rate data were collected by measuring the change in the specific weight of sintered compacts. The oxidized samples were examined by optical and scanning electron microscopy, energy dispersive spectroscopy, and thin film diffractometry. In the first few hours of exposure to air, the oxidation of TiSi2 followed parabolic kinetics. The rate of oxidation of the samples increased only slightly with surface porosity. This was attributed to the formation of a dense, protective and uniform titania-silica glass layer. The activation energy of the oxidation process was determined to be about 29 kcal mol−1. This value is consistent with a mechanism in which the diffusion of oxygen through the silicate film is the rate-determining step. Resume L'oxydation du Bisiliciure de titane, TiSi2, a ete etudiee pour un intervalle de temperature de 800–1300°C dans l'air. Les donnees associees aux tau x de reaction ont et...

The effect of impurities on the oxidation resistance of TiSi2 was studied. Iron additions caused a slight increase in the oxidation rate, while samples containing aluminum or copper showed no useful resistance to oxidation. The oxidized samples were examined by optical and SE microscopy, EDS, and thin film diffractometry.

Volatile hydrocarbon production by Ascocoryne sacroides was studied over its growth cycle. Gas-phase compounds were measured continuously with a proton transfer reaction-mass spectrometry (PTR-MS) and at distinct time points with gas chromatography-mass spectrometry (GC-MS) using head space solid phase microextraction (SPME). The PTR-MS ion signal permitted temporal resolution of the volatile production while the SPME results revealed distinct compound identities. The quantitative PTR-MS results showed the volatile production was dominated by ethanol and acetaldehyde, while the concentration of the remainder of volatiles consistently reached 2,000 ppbv. The measurement of alcohols from the fungal culture by the two techniques correlated well. Notable compounds of fuel interest included nonanal, 1-octen-3-ol, 1-butanol, 3-methyl- and benzaldehyde. Abiotic comparison of the two techniques demonstrated SPME fiber bias toward higher molecular weight compounds, making quantitative efforts with SPME impractical. Together, PTR-MS and SPME GC-MS were shown as valuable tools for characterizing volatile fuel compound production from microbiological sources.