1,115 research outputs found
Margaropus wileyi sp. nov. (Ixodoidea, Ixodidae), a new species of tick from the reticulated giraffe
Descriptions are given of the male and female of Margaropus wileyi sp. nov. collected from the reticulated giraffe in Kenya. A key is given to the three species now known in the genus Margaropus and their differential diagnosis is discussed.The articles have been scanned in colour with a HP Scanjet 5590;
300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
ethical reasons and political commitment
Political commitments to resist oppression play a central role in the moral lives of many people. Such commitments are also a source of ethical reasons. They influence and organize ethical beliefs, emotions and reasons in an ongoing way. Political commitments to address oppression often contain a concern for the dignity and well-being of others and the objects of political commitments often have value, according to ideal moral theories, such as Kantian and utilitarian theory. However, ideal moral theories do not fully explain the ethical reasons political commitments engender. First, ideal moral theories do not explain the normative priority that agents give to politically committed ethical reasons. Their profound effect on a politically committed agentâs ethical deliberation and choice and the precedence they are given over other ends cannot be wholly understood through the moral obligations within ideal theories. Second, although politically committed reasons are valuable in ideal theory for the benefits they bring to others, they are not fungible with other reasons ideal theory would regard as having equal ethical value. A person might substitute another beneficial humanitarian aim for that to which she is politically committed and nevertheless regard herself as having done a morally wrong thing for failing or betraying her commitment. Politically committed ethical reasons are also motivated and informed by the social location of agents and their relationship to structures of oppression. Although there are universal ethical reasons to oppose oppression, this means that some of a personâs actual ethical reasons will be irreducibly particular
Sum rule for the backward spin polarizability of the nucleon from a backward dispersion relation
A new sum rule for , the backward spin polarizability of the
nucleon, is derived from a backward-angle dispersion relation. Taking into
account single- and multi-pion photoproduction in the s-channel up to the
energy 1.5 GeV and resonances in the t-channel with mass below 1.5 GeV, it is
found for the proton and neutron that = -39.5 +/- 2.4 and
= 52.5 +/- 2.4, respectively, in units of 10^{-4} fm^4.Comment: 10 pages, 1 figure, revtex. Submitted to Phys. Lett.
11ÎČ-hydroxysteroid dehydrogenase type I inhibition in solid tumours
Glucocorticoids, key hormonal regulators of the stress response, powerfully influence
inflammation and metabolism. Reducing excessive glucocorticoid exposure is
beneficial in treating metabolic and cognitive disorders, but manipulating systemic
endogenous glucocorticoids risks compromising their beneficial effects. The enzyme
11ÎČ-hydroxysteroid dehydrogenase type 1 (11ÎČ-HSD1) activates glucocorticoids in
target tissues and thus inhibition of this enzyme presents a clinical opportunity to
reduce tissue-specific glucocorticoid action. Active glucocorticoids also exert potent
angiostatic effects by binding the glucocorticoid receptor (GR), and 11ÎČ-HSD1
inhibitors have proven beneficial in models of myocardial infarction by promoting
angiogenesis. The possibility that 11ÎČ-HSD1 inhibitors may increase pathological
angiogenesis, such as that seen in solid tumours, remains unaddressed. This project
tested the hypothesis that 11ÎČ-HSD1 inhibition promotes tumour growth as a result of
increased angiogenesis, using murine models of squamous cell carcinoma (SCC) and
pancreatic ductal adenocarcinoma (PDAC).
Murine SCC or PDAC cells were injected (1x106 cells/flank) into WT female mice fed
either standard diet, or diet containing the 11ÎČ-HSD1 inhibitor UE2316 (175 mg/kg,
N=6/group), or into 11ÎČ-HSD1 knockout (Del1) mice fed standard diet. Developing
tumours were measured by callipers over several weeks, before animals were culled
and tissues collected. SCC tumours grew more rapidly in UE2316-treated mice to
reach a significantly (P<0.01) larger final volume (0.158 ± 0.037 cm3) than in control
mice (0.051 ± 0.007 cm3). PDA tumours were unaffected by 11ÎČ-HSD1 inhibition or
deletion. Immunofluorescent co-staining of tumour sections for CD31/α-smooth
muscle actin revealed no differences in vessel density, and RT-qPCR showed no
difference in angiogenic factor expression, after 11ÎČ-HSD1 inhibition/deletion in
either tumour type. GR and 11ÎČ-HSD1 RNA expression were greater in SCC vs PDAC
tumours (P<0.001), as was 11ÎČ-HSD1 activity (P<0.0001).
In studies using the aortic ring assay of ex vivo angiogenesis, 11ÎČ-HSD1 deletion, but
not inhibition with UE2316, was shown to prevent glucocorticoid-mediated
angiostasis. The growth/viability of tumour cell lines was not affected by UE2316 or
corticosterone, as assessed by live cell imaging using the Incucyte imaging system.
RNA-sequencing of SCC tumours revealed that multiple factors involved in the innate
immune/inflammatory response were reduced in UE2316-treated tumours, and that
extracellular matrix regulation was also altered by UE2316. Imaging of tumour
sections using Second Harmonic Generation microscopy confirmed that UE2316
altered Type I collagen deposition in SCC (P<0.001) but not PDAC.
11ÎČ-HSD1 inhibition can increase tumour growth, possibly via suppression of
inflammatory/immune cell signalling and alteration of the extracellular matrix, and
tumours with higher GR and 11ÎČ-HSD1 content, such as SCC, may be more at risk.
Interestingly this investigation found no evidence of increased angiogenesis in vivo or
ex vivo after UE2316 treatment, suggesting that 11ÎČ-HSD1 inhibition does not
promote angiogenesis in all ischaemic environments. Future work must focus on the
effects of 11ÎČ-HSD1 inhibition on the immune and extracellular matrix component of
the tumour microenvironment. While promotion of pathological angiogenesis does not
appear to pose a major threat, 11ÎČ-HSD1 inhibitors may still interact with the immune
and inflammatory environment in tumours to the detriment of health
Post-Newtonian Gravitational Radiation
1 Introduction 2 Multipole Decomposition 3 Source Multipole Moments 4
Post-Minkowskian Approximation 5 Radiative Multipole Moments 6 Post-Newtonian
Approximation 7 Point-Particles 8 ConclusionComment: 46 pages, in Einstein's Field Equations and Their Physical
Implications, B. Schmidt (Ed.), Lecture Notes in Physics, Springe
Three-spined stickleback armour predicted by body size, minimum winter temperature and pH
Similar phenotypes evolve under equivalent environmental conditions through parallel evolution. Because they have repeatedly invaded and adapted to new freshwater environments, the three-spined stickleback (Gasterosteus aculeatus) offers a powerful system for understanding the agents of selection in nature that drive parallel evolution. Here we examine the ecological and environmental variables responsible for morphological variation in three-spined stickleback populations across its European range. We collected fish from 85 populations, encompassing much of the European latitudinal range of the species and including lowland rivers and lakes, coastal lagoons, and moorland ponds. We measured biotic and environmental variables at all sites along with morphological traits for 2,358 individuals. Using an information theory approach, we identified body size, minimum average winter temperature and pH as primary predictors of stickleback armour evolution, challenging current hypotheses for stickleback morphological diversification and demonstrating the fundamental role played by body size and scaling in mediating responses to selection. Stickleback lateral plate phenotype represents a potentially powerful tool for monitoring change in climate variables across the northern temperate region
Quantification of 11ÎČ-hydroxysteroid dehydrogenase 1 kinetics and pharmacodynamic effects of inhibitors in brain using mass spectrometry imaging and stable-isotope tracers in mice
Omnivoria e repartição de recursos em åguas pobres em nutrientes da Bacia do Rio Negro
Amazonian biodiversity is notorious, this is also valid for the fauna of the mineral-deficient waters of the Rio Negro System. Some 25 years of research on the benthic fauna of Central Amazonian streams resulted in species-rich foodwebs with a high degree of omnivory within dense animal communities. To exemplify the taxonomic range of omnivorous consumers, the detailed resource spectra of 18 consumer species, including Protozoa (2 species), Platyhelminthes (1 species), insects (2 species), fish (6 species) and shrimps (Decapoda, 7 species), associated primarily with the benthic habitats of Rio Negro tributaries, are presented. Special features of omnivory are characterized, and the importance of litter-decomposing fungi as essential energy input into the foodwebs is documented. It is shown that general omnivory -diverse omnivore consumers sharing most of the resource types- is a prevalent feature. The relevance of this general omnivory for the maintenance of biodiversity is discussed.A biodiversidade do Amazonas Ă© notĂłrio e isto tambĂ©m Ă© vĂĄlido para as ĂĄguas pobres em nutrientes da bacia do Rio Negro. Uma pesquisa de 25 anos da fauna bĂ©ntica de igarapĂ©s da AmazĂŽnia Central resultou em redes alimentares caraterizadas por alta diversidade de espĂ©cies, por intensa omnivoria e por alta densidade populacional. Para demonstrar a generalidade taxonĂŽmica de omnivoria no bentos dos igarapĂ©s, sĂŁo apresentados as listas de presas / recursos de 18 espĂ©cies de consumidores, sendo Protozoa (2 epĂ©cies), Platyhelminthes (1 espĂ©cie), insetos (2 espĂ©cies), peixes (6 espĂ©cies) e camarĂ”es (Decapoda, 7 espĂ©cies). Diferentes categorias de omnivoria sĂŁo apresentados, e a importĂąncia de fungos decompositores da liteira submersa como input bĂĄsico de energia nas redes alimentares Ă© demonstrada. Ă prevalente a omnivoria geral, sendo que as diferentes espĂ©cies omnĂvoros estĂŁo utilizando os mesmos recursos. Considera- se a relevĂąncia desta omnivoria geral para a manutenção da biodiversidade
Structural response of Caribbean dry forests to hurricane winds: a case study from Guanica Forest, Puerto Rico
Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple-stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes, so wind may also influence forest stature. Furthermore, these forests also tend to grow on soils with low amounts of available phosphorus, which may also influence structure. The objective of this study was to assess the role of high winds in structuring dry forest, and to determine whether soil nutrient pools influence forest response following hurricane disturbance.
Methods: Over 2000 stems in five plots were sampled for hurricane effects within 1 week after Hurricane Georges impacted field sites in 1998. Sprout initiation, growth, and mortality were analysed for 1407 stems for 2 years after the hurricane. Soil nutrient pools were measured at the base of 456 stems to assess association between nutrients and sprout dynamics.
Results: Direct effects of the hurricane were minimal, with stem mortality at \u3c 2% and structural damage to stems at 13%, although damage was biased toward stems of larger diameter. Sprouting response was high . over 10 times as many trees had sprouts after the hurricane as before. The number of sprouts on a stem also increased significantly. Sprouting was common on stems that only suffered defoliation or had no visible effects from the hurricane. Sprout survival after 2 years was also high (\u3e 86%). Soil nutrient pools had little effect on forest response as a whole, but phosphorus supply did influence sprout dynamics on four of the more common tree species. Main Conclusions: Hurricanes are able to influence Caribbean tropical dry forest structure by reducing average stem diameter and basal area and generating significant sprouting responses. New sprouts, with ongoing survival, will maintain the high frequency of multi-stemmed trees found in this region. Sprouting is not limited to damaged stems, indicating that trees are responding to other aspects of high winds, such as short-term gravitational displacement or sway. Soil nutrients play a secondary role in sprouting dynamics of a subset of species. The short, shrubby forest structure common to the Caribbean can arise naturally as a response to hurricane winds
A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses
We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermisâoutermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants
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