Common Epidermal Lesions of the Bowhead Whale, Balaena Mysticetus

Samples of common skin abnormalities from 23 subsistence-harvested bowhead whales (Balaena mysticetus) were examined. Most lesions fell into three broad classes: shallow lacerations, circular depressions, and epidermal sloughing. Both circular depression lesions and epidermal sloughing lesions may be divided into more than one subgroup based on morphological criteria. Examination of each of the subgroups using light and scanning electron microscopy suggests relationships among the subgroups of a class. These proposed relationships are discussed, as are some possible etiologies. Scanning electron microscopy reveals abundant bacteria and diatoms present in association with each lesion class but no evidence of a particular association characteristic of a lesion class. The microflora were especially abundant wherever the stratum spinosum was exposed at the skin surface

The Morphological Effects of Two Antimicrobial Peptides, Hecate-1 and Melittin, on Escherichia Coli

The effects of the 26 amino acid, cationic, amphipathic, antibacterial peptide melittin and hecate-1, a 23 amino acid analog of it, on the gram negative bacterium Escherichia coli were investigated using scanning electron microscopy (SEM), transmission electron micros-copy (TEM), and freeze-fracture. Both peptides killed virtually all bacteria at the peptide concentration and cell density used. TEM and SEM revealed aggregates of bacteria entangled with material extruded from the bacterial surfaces. SEM revealed irregular bacterial surfaces with bleb-like projections. TEM and freeze-fracture indicate that the bacterial inner and outer membranes, as well as the peptidoglycan layer between, were extensively damaged. The cytoplasmic contents of the cells, however, did not appear radically disturbed, providing little evidence for osmotically induced cytolysis

Do geese fully develop brood patches? A histological analysis of lesser snow geese (Chen caerulescens caerulescens) and Ross\u27s geese (C. rossii)

Most birds develop brood patches before incubation; epidermis and dermis in the brood patch region thicken, and the dermal connective tissue becomes increasingly vascularized and infiltrated by leukocytes. However, current dogma states that waterfowl incubate without modifications of skin within the brood patch region. The incubation periods of lesser snow geese (Chen caerulescens caerulescens; hereafter called snow geese) and Ross\u27s geese (C. rossii) are 2-6 days shorter than those of other goose species; only females incubate. Thus, we hypothesized that such short incubation periods would require fully developed brood patches for sufficient heat transfer from incubating parents to eggs. We tested this hypothesis by analyzing the skin histology of abdominal regions of snow and Ross\u27s geese collected at Karrak Lake, Nunavut, Canada. For female snow geese, we found that epidermis and dermis had thickened and vascularization of dermis was 14 times greater, on average, than that observed in males (n=5 pairs). Our results for Ross\u27s geese (n=5 pairs) were more variable, wherein only one of five female Ross\u27s geese fully developed a brood patch. Our results are consistent with three hypotheses about brood patch development and its relationship with different energetic cost-benefit relationships, resulting from differences in embryonic development and body size. © Springer-Verlag 2006

Health related quality of life in patients with type I diabetes mellitus:generic & disease-specific measurement

Background & objectives: An ideal instrument for the assessment of health related quality of life (HRQOL) in patients with diabetes mellitus type I (T1DM) should incorporate the benefits of both generic and disease-specific instruments. The objective of this study was to investigate the responsiveness and the ability to provide information about diabetes-specific associations with HRQOL, of two generic instruments, in comparison with two diabetes-specific instruments, in patients with T1DM. Methods: In a Dutch cohort of 234 patients with T1DM we longitudinally assessed HRQOL using both generic and diabetes-specific instruments. We investigated the responsiveness, the associations with diabetes-specific variables and the Identification of specific patients by the Instruments used. Results: The generic RAND-36 was able to detect statistically significant and clinically relevant changes in HRQOL over time. Moreover, the RAND-36 was associated with (changes In) diabetes. specific variables. The generic and diabetes-specific Instruments partly Identified different patients with lowest HRQOL. Interpretation & conclusion: The RAND-36 was highly responsive to changes in HRQOL in patients with T1DM and revealed diabetes-specific associations with HRQOL. A low correlation between the generic and diabetes-specific instruments and partly different identification of patients with lower HRQOL support the complementary use of these instruments In patients with T1DM

Integrability of irrotational silent cosmological models

We revisit the issue of integrability conditions for the irrotational silent cosmological models. We formulate the problem both in 1+3 covariant and 1+3 orthonormal frame notation, and show there exists a series of constraint equations that need to be satisfied. These conditions hold identically for FLRW-linearised silent models, but not in the general exact non-linear case. Thus there is a linearisation instability, and it is highly unlikely that there is a large class of silent models. We conjecture that there are no spatially inhomogeneous solutions with Weyl curvature of Petrov type I, and indicate further issues that await clarification.Comment: Minor corrections and improvements; 1 new reference; to appear Class. Quantum Grav.; 16 pages Ioplpp

Assessing environmental change associated with early Eocene hyperthermals in the Atlantic Coastal Plain, USA

Eocene transient global warming events (hyperthermals) can provide insight into a future warmer world. While much research has focused on the Paleocene-Eocene Thermal Maximum (PETM), hyperthermals of a smaller magnitude can be used to characterize climatic responses over different magnitudes of forcing. This study identifies two events, namely the Eocene Thermal Maximum 2 (ETM2 and H2), in shallow marine sediments of the Eocene-aged Salisbury Embayment of Maryland, based on magnetostratigraphy, calcareous nannofossil, and dinocyst biostratigraphy, as well as the recognition of negative stable carbon isotope excursions (CIEs) in biogenic calcite. We assess local environmental change in the Salisbury Embayment, utilizing clay mineralogy, marine palynology, δ18O of biogenic calcite, and biomarker paleothermometry (TEX86). Paleotemperature proxies show broad agreement between surface water and bottom water temperature changes. However, the timing of the warming does not correspond to the CIE of the ETM2 as expected from other records, and the highest values are observed during H2, suggesting factors in addition to pCO2 forcing have influenced temperature changes in the region. The ETM2 interval exhibits a shift in clay mineralogy from smectite-dominated facies to illite-rich facies, suggesting hydroclimatic changes but with a rather dampened weathering response relative to that of the PETM in the same region. Organic walled dinoflagellate cyst assemblages show large fluctuations throughout the studied section, none of which seem systematically related to CIE warming. These observations are contrary to the typical tight correspondence between climate change and assemblages across the PETM, regionally and globally, and ETM2 in the Arctic Ocean. The data do indicate very warm and (seasonally) stratified conditions, likely salinity-driven, across H2. The absence of evidence for strong perturbations in local hydrology and nutrient supply during ETM2 and H2, compared to the PETM, is consistent with the less extreme forcing and the warmer pre-event baseline, as well as the non-linear response in hydroclimates to greenhouse forcing

High-throughput screening of monoclonal antibodies against plant cell wall glycans by hierarchical clustering of their carbohydrate microarray binding profiles

Antibody-producing hybridoma cell lines were created following immunisation with a crude extract of cell wall polymers from the plant Arabidopsis thaliana. In order to rapidly screen the specificities of individual monoclonal antibodies (mAbs), their binding to microarrays containing 50 cell wall glycans immobilized on nitrocellulose was assessed. Hierarchical clustering of microarray binding profiles from newly produced mAbs, together with the profiles for mAbs with previously defined specificities allowed the rapid assignments of mAb binding to antigen classes. mAb specificities were further investigated using subsequent immunochemical and biochemical analyses and two novel mAbs are described in detail. mAb LM13 binds to an arabinanase-sensitive pectic epitope and mAb LM14, binds to an epitope occurring on arabinogalactan-proteins. Both mAbs display novel patterns of recognition of cell walls in plant materials