Osmium isotopic evidence for ancient subcontinental lithospheric mantle beneath the kerguelen islands, southern indian ocean

Upper mantle xenoliths found in ocean island basalts are an important window through which the oceanic mantle lithosphere may be viewed directly. Osmium isotopic data on peridotite xenoliths from the Kerguelen Islands, an archipelago that is located on the northern Kerguelen Plateau in the southern Indian Ocean, demonstrate that pieces of mantle of diverse provenance are present beneath the Islands. In particular, peridotites with unradiogenic osmium and ancient rhenium-depletion ages (to 1.36 x 10(9) years old) may be pieces of the Gondwanaland subcontinental lithosphere that were incorporated into the Indian Ocean lithosphere as a result of the rifting process.     

A Paternal Fish Oil Diet Preconception Modulates the Gut Microbiome and Attenuates Necrotizing Enterocolitis in Neonatal Mice

Epidemiology and animal studies suggest that a paternal history of toxicant exposure contributes to the developmental origins of health and disease. Using a mouse model, our laboratory previously reported that a paternal history of in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased his offspring’s risk of developing necrotizing enterocolitis (NEC). Additionally, our group and others have found that formula supplementation also increases the risk of NEC in both humans and mice. Our murine studies revealed that intervening with a paternal fish oil diet preconception eliminated the TCDD-associated outcomes that are risk factors for NEC (e.g., intrauterine growth restriction, delayed postnatal growth, and preterm birth). However, the efficacy of a paternal fish oil diet in eliminating the risk of disease development in his offspring was not investigated. Herein, reproductive-age male mice exposed to TCDD in utero were weaned to a standard or fish oil diet for one full cycle of spermatogenesis, then mated to age-matched unexposed females. Their offspring were randomized to a strict maternal milk diet or a supplemental formula diet from postnatal days 7–10. Offspring colon contents and intestines were collected to determine the onset of gut dysbiosis and NEC. We found that a paternal fish oil diet preconception reduced his offspring’s risk of toxicant-driven NEC, which was associated with a decrease in the relative abundance of the Firmicutes phylum, but an increase in the relative abundance of the Negativicutes class.     

First case of a dog infected with Aspergillus (Phialosimplex) caninus in Australasia

ABSTRACT

Case history: A 2-year-old Rottweiler dog from Perth (WA, Australia) was referred for assessment of a chronic productive cough and weight loss.

Clinical findings: Severely enlarged bilateral superficial cervical lymph nodes and severely enlarged abdominal organs were present. The body condition score was poor and there was moderate muscle wasting. Thoracic and abdominal computed tomography images revealed severe diffuse enlargement of thoracic and abdominal lymph nodes, hepatomegaly and diffuse splenomegaly. A diffuse bronchial pattern with severe multifocal saccular bronchiectasis was identified in the lungs.

Diagnostic findings: Fungal organisms were seen within macrophages on cytological preparations and on histopathological sections of biopsies of the superficial cervical lymph node. Macrophages contained intracytoplasmic, non-filamentous round-to-ovoid organisms, which varied in size from 5–30?µm in diameter with variable morphology. Budding was not observed, and no hyphae were present. Fungal culture of lymph node tissue resulted in growth of Aspergillus (Phialosimplex) caninus which was confirmed by amplification and sequencing of a segment of the 16S-23S rRNA internal transcribed spacer. Concurrent bacterial bronchitis was diagnosed on culture of broncho-alveolar fluid.

Diagnosis: Disseminated aspergillosis caused by Aspergillus caninus.

Clinical relevance: This is believed to be the first report of infection caused by A. caninus in a dog in Australasia. The dog was treated with itraconazole for 7 months and was still alive 7 months after the start of treatment.     

Challenges and a checklist for biodiversity conservation in fire-prone forests: Perspectives from the Pacific Northwest of USA and Southeastern Australia

Conserving biodiversity in fire-prone forest ecosystems is challenging for several reasons including differing and incomplete conceptual models of fire-related ecological processes, major gaps in ecological and management knowledge, high variability in fire behavior and ecological responses to fires, altered fire regimes as a result of land-use history and climate change, and the increasing encroachment into forest landscapes by humans. We briefly compare two ecologically distinct fire-prone forest regions, the Pacific Northwest, USA and southeastern Australia with the goal of finding ecological conservation generalities that transcend regional differences as well as differences in scientific concepts and management. We identify the major conceptual scientific and conservation challenges and then present a checklist of questions that need to be answered to implement place-based approaches to conserving biodiversity in fire-prone forest ecosystems. The two regions exhibit both similarities and differences in how biodiversity conservation is conceptualized and applied. Important research and management challenges include: understanding fire-prone systems as coupled natural-human systems, using the disturbance regime concept in multiple ways, dealing with large fire events, using language about the effects of fire with more precision, and researching and monitoring fire and biodiversity at multiple spatial scales. Despite the weaknesses of present conceptual models, it is possible to develop a checklist of principles or questions that can be used to guide management and conservation at local scales across systems. Our list includes: establishing the socio-economic context of fire management, identifying disturbance regimes that will meet conservation goals, moving beyond fuel treatments as a goal, basing management goals on vital attributes of species, and planning for large events including post-fire responses.     

Soybean genotype evaluation for iron deficiency chlorosis using sodium bicarbonate and tissue culture

The evaluation of soybean genotypes for resistance to iron deficiency through field experiments is complicated by variation in symptom expression. The objective of this study was to develop a tissue culture technique that could distinguish between Fe‐efficient and Fe‐inefficient genotypes. Ten soybean genotypes varying in sensitivity to iron deficiency were planted at 5 locations and rated based on chlorosis expression. For the lab evaluation, friable callus of the ten genotypes was placed on a 4MSII medium amended with 10 mM NaHCO₃. Callus growth reduction relative to a control medium without NaHCO₃ was recorded. Callus weight of all cultivars was affected by the addition of NaHCO₃ however, significant differences in growth reduction among genotypes was observed. The high correlation between callus growth reduction and field chlorosis ratings observed (r²=0.92) and the fact that the expiant source plant can be grown to produce seed indicates that this technique would be useful in a soybean breeding program.     

Ground-based near-infrared imaging observations of venus during the galileo encounter

Near-infrared images of Venus, obtained from a global network of ground-based observatories during January and February 1990, document the morphology and motions of the night-side near-infrared markings before, during, and after the Galileo Venus encounter. A dark cloud extended halfway around the planet at low latitudes (>+/-40 degrees ) and persisted throughout the observing program. It had a rotation period of 5.5 +/- 0.15 days. The remainder of this latitude band was characterized by small-scale (400 to 1000 kilometers) dark and bright markings with rotation periods of 7.4 +/- 1 days. The different rotation periods for the large dark cloud and the smaller markings suggests that they are produced at different altitudes. Mid-latitudes (+/-40 degrees to 60 degrees ) were usually occupied by bright east-west bands. The highest observable latitudes (+/-60 degrees to 70 degrees ) were always dark and featureless, indicating greater cloud opacity. Maps of the water vapor distribution show no evidence for large horizontal gradients in the lower atmosphere of Venus.     

Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric CO2

Measurements of midday vertical atmospheric CO2 distributions reveal annual-mean vertical CO2 gradients that are inconsistent with atmospheric models that estimate a large transfer of terrestrial carbon from tropical to northern latitudes. The three models that most closely reproduce the observed annual-mean vertical CO2 gradients estimate weaker northern uptake of -1.5 petagrams of carbon per year (Pg C year(-1)) and weaker tropical emission of +0.1 Pg C year(-1) compared with previous consensus estimates of -2.4 and +1.8 Pg C year(-1), respectively. This suggests that northern terrestrial uptake of industrial CO2 emissions plays a smaller role than previously thought and that, after subtracting land-use emissions, tropical ecosystems may currently be strong sinks for CO2.     

Decline of an isolated timber rattlesnake (Crotalus horridus) population: Interactions between climate change, disease, and loss of genetic diversity

Extinction of populations from anthropogenic forces rarely has a single cause. Instead, population declines result from a variety of factors, including habitat loss, inbreeding depression, disease, and climate change. These impacts often have synergistic effects that can lead to rapid decline in isolated populations, but case studies documenting such processes are rare. Here, we describe the recent decline of the last known population of timber rattlesnakes (Crotalus horridus) in the state of New Hampshire. We used polymorphic nuclear DNA markers to compare genetic diversity of this population to other populations in the region that are not isolated. We also compare results from ongoing field monitoring of these populations. Genetic analyses reveal that the New Hampshire population lacks genetic diversity and exhibits signs of a recent bottleneck. New Hampshire snakes also exhibited high levels of morphological abnormalities (unique piebald coloration, amelanistic tongues) indicative of inbreeding depression. Furthermore, after a year with exceptionally high summer rainfall, a skin infection of unknown etiology caused significant mortality in the New Hampshire population, whereas other surveyed non-inbred populations were unaffected. This case study demonstrates how different anthropogenic impacts on natural environments can interact in unexpected ways to drive threatened populations toward extinction.     

Determination of the N-glycosylation patterns of seed proteins: applications to determine the authenticity and substantial equivalence of genetically modified (GM) crops

Methods have been developed to determine the N-glycosylation pattern of proteins at the single-seed level in two different biological systems. These were the well-characterized and widely consumed storage protein phaseolin from several species of Phaseolus (bean) and the α-amylase inhibitor from the same Phaseolus species expressed transgenically in pea. The N-glycosylation pattern of the α-amylase inhibitor expressed transgenically in pea was different from that of the inhibitor present in common bean (P. vulgaris), the species of origin of the gene. However, multivariate analysis showed that the differences in N-glycan patterns between the α-amylase inhibitors from common bean and pea were less than those between the inhibitors from common bean and two related bean species, lima bean (Phaseolus lunatus) and tepary bean (Phaseolus acutifolius).