3,245 research outputs found
Who's behind that mask and cape? The Asian leopard cat's Agouti (ASIP) allele likely affects coat colour phenotype in the Bengal cat breed.
Coat colours and patterns are highly variable in cats and are determined mainly by several genes with Mendelian inheritance. A 2-bp deletion in agouti signalling protein (ASIP) is associated with melanism in domestic cats. Bengal cats are hybrids between domestic cats and Asian leopard cats (Prionailurus bengalensis), and the charcoal coat colouration/pattern in Bengals presents as a possible incomplete melanism. The complete coding region of ASIP was directly sequenced in Asian leopard, domestic and Bengal cats. Twenty-seven variants were identified between domestic and leopard cats and were investigated in Bengals and Savannahs, a hybrid with servals (Leptailurus serval). The leopard cat ASIP haplotype was distinguished from domestic cat by four synonymous and four non-synonymous exonic SNPs, as well as 19 intronic variants, including a 42-bp deletion in intron 4. Fifty-six of 64 reported charcoal cats were compound heterozygotes at ASIP, with leopard cat agouti (A(P) (be) ) and domestic cat non-agouti (a) haplotypes. Twenty-four Bengals had an additional unique haplotype (A2) for exon 2 that was not identified in leopard cats, servals or jungle cats (Felis chaus). The compound heterozygote state suggests the leopard cat allele, in combination with the recessive non-agouti allele, influences Bengal markings, producing a darker, yet not completely melanistic coat. This is the first validation of a leopard cat allele segregating in the Bengal breed and likely affecting their overall pelage phenotype. Genetic testing services need to be aware of the possible segregation of wild felid alleles in all assays performed on hybrid cats
Weighted entropy and optimal portfolios for risk-averse Kelly investments
Following a series of works on capital growth investment, we analyse
log-optimal portfolios where the return evaluation includes `weights' of
different outcomes. The results are twofold: (A) under certain conditions, the
logarithmic growth rate leads to a supermartingale, and (B) the optimal
(martingale) investment strategy is a proportional betting. We focus on
properties of the optimal portfolios and discuss a number of simple examples
extending the well-known Kelly betting scheme.
An important restriction is that the investment does not exceed the current
capital value and allows the trader to cover the worst possible losses.
The paper deals with a class of discrete-time models. A continuous-time
extension is a topic of an ongoing study
Gendered perspectives on men’s changing familial roles in postwar England, c. 1950-1990
This article examines the ways in which men and women remember men’s place in, and experiences of, family life in postwar England during a period when a new ideal of fatherhood arguably emerged. Based on forty-four oral history testimonies with men and women, this article adds a new dimension to existing literature in gender history by closely examining men and women’s perspectives on the same issues. Focusing on decisions around family planning, experiences of pregnancy and birth, and the division of labour in the home, the article analyses how men and women understood their respective roles as parents-to-be and as new parents; how they negotiated the expectations of those around them; and the extent to which the gendering of childcare responsibilities persisted in the decades between 1950 and 199
Selling Health Promotion to Corporate America: Uses and Abuses of the Economic Argument
Economic considerations constitute a significant factor in businesses' interest in adopting health promotion (HP) programs and in the wellness community's attempts to sell such programming to business. Substantial elements of both the business and wellness communities believe that HP programs are financially profitable, in addition to, and as a result of, improving employees' health. Examination of the foundation of this belief, however, leads to the conclusion that underlying analyses have been techni cally flawed and have ignored important costs of HP programs. This article discusses the limitations of these analyses and outlines the framework of a model that could provide a sound assessment of the economics of workplace HP programs. In general, it is expected that resultant analyses would find less direct profit potential in work place HP programs but would emphasize the cost-effectiveness of many such efforts. The latter would force recognition that health, and not profit, is the principal benefit of health promotion programming. The distinction between the cost-effectiveness and cost-saving potential of health promotion is one that all interested parties should master.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66785/2/10.1177_109019818701400106.pd
Defective platelet function in Niemann-Pick disease type C1
Niemann-Pick disease type C (NPC) is a neurodegenerative lysosomal storage disorder caused by mutations in either NPC1 (95% of cases) or NPC2. Reduced late endosome/lysosome calcium (Ca2+) levels and the accumulation of unesterified cholesterol and sphingolipids within the late endocytic system characterize this disease. We previously reported impaired lysosome-related organelle (LRO) function in Npc1−/− Natural Killer cells; however, the potential contribution of impaired acid compartment Ca2+ flux and LRO function in other cell types has not been determined. Here, we investigated LRO function in NPC1 disease platelets. We found elevated numbers of circulating platelets, impaired platelet aggregation and prolonged bleeding times in a murine model of NPC1 disease. Electron microscopy revealed abnormal ultrastructure in murine platelets, consistent with that seen in a U18666A (pharmacological inhibitor of NPC1) treated megakaryocyte cell line (MEG-01) exhibiting lipid storage and acidic compartment Ca2+ flux defects. Furthermore, platelets from NPC1 patients across different ages were found to cluster at the lower end of the normal range when platelet numbers were measured and had platelet volumes that were clustered at the top of the normal range. Taken together, these findings highlight the role of acid compartment Ca2+ flux in the function of platelet LROs
Drug-resistant EGFR mutations promote lung cancer by stabilizing interfaces in ligand-free kinase-active EGFR oligomers
The Epidermal Growth Factor Receptor (EGFR) is frequently found to be mutated in non-small cell lung cancer. Oncogenic EGFR has been successfully targeted by tyrosine kinase inhibitors, but acquired drug resistance eventually overcomes the efficacy of these treatments. Attempts to surmount this therapeutic challenge are hindered by a poor understanding of how and why cancer mutations specifically amplify ligand-independent EGFR auto-phosphorylation signals to enhance cell survival and how this amplification is related to ligand-dependent cell proliferation. Here we show that drug-resistant EGFR mutations manipulate the assembly of ligand-free, kinase-active oligomers to promote and stabilize the assembly of oligomer-obligate active dimer sub-units and circumvent the need for ligand binding. We reveal the structure and assembly mechanisms of these ligand-free, kinase-active oligomers, uncovering oncogenic functions for hitherto orphan transmembrane and kinase interfaces, and for the ectodomain tethered conformation of EGFR. Importantly, we find that the active dimer sub-units within ligand-free oligomers are the high affinity binding sites competent to bind physiological ligand concentrations and thus drive tumor growth, revealing a link with tumor proliferation. Our findings provide a framework for future drug discovery directed at tackling oncogenic EGFR mutations by disabling oligomer-assembling interactions
The Citation Field of Evolutionary Economics
Evolutionary economics has developed into an academic field of its own,
institutionalized around, amongst others, the Journal of Evolutionary Economics
(JEE). This paper analyzes the way and extent to which evolutionary economics
has become an interdisciplinary journal, as its aim was: a journal that is
indispensable in the exchange of expert knowledge on topics and using
approaches that relate naturally with it. Analyzing citation data for the
relevant academic field for the Journal of Evolutionary Economics, we use
insights from scientometrics and social network analysis to find that, indeed,
the JEE is a central player in this interdisciplinary field aiming mostly at
understanding technological and regional dynamics. It does not, however, link
firmly with the natural sciences (including biology) nor to management
sciences, entrepreneurship, and organization studies. Another journal that
could be perceived to have evolutionary acumen, the Journal of Economic Issues,
does relate to heterodox economics journals and is relatively more involved in
discussing issues of firm and industry organization. The JEE seems most keen to
develop theoretical insights
Climate change adaptation and cross-sectoral policy coherence in southern Africa
To be effective, climate change adaptation needs to be mainstreamed across multiple sectors and greater policy coherence is essential. Using the cases of Malawi, Tanzania and Zambia, this paper investigates the extent of coherence in national policies across the water and agriculture sectors and to climate change adaptation goals outlined in national development plans. A two-pronged qualitative approach is applied using Qualitative Document Analysis of relevant policies and plans, combined with expert interviews from non-government actors in each country. Findings show that sector policies have differing degrees of coherence on climate change adaptation, currently being strongest in Zambia and weakest in Tanzania. We also identify that sectoral policies remain more coherent in addressing immediate-term disaster management issues of floods and droughts rather than longer-term strategies for climate adaptation. Coherence between sector and climate policies and strategies is strongest when the latter has been more recently developed. However to date, this has largely been achieved by repackaging of existing sectoral policy statements into climate policies drafted by external consultants to meet international reporting needs and not by the establishment of new connections between national sectoral planning processes. For more effective mainstreaming of climate change adaptation, governments need to actively embrace longer-term cross-sectoral planning through cross-Ministerial structures, such as initiated through Zambia’s Interim Climate Change Secretariat, to foster greater policy coherence and integrated adaptation planning
The interplay of microscopic and mesoscopic structure in complex networks
Not all nodes in a network are created equal. Differences and similarities
exist at both individual node and group levels. Disentangling single node from
group properties is crucial for network modeling and structural inference.
Based on unbiased generative probabilistic exponential random graph models and
employing distributive message passing techniques, we present an efficient
algorithm that allows one to separate the contributions of individual nodes and
groups of nodes to the network structure. This leads to improved detection
accuracy of latent class structure in real world data sets compared to models
that focus on group structure alone. Furthermore, the inclusion of hitherto
neglected group specific effects in models used to assess the statistical
significance of small subgraph (motif) distributions in networks may be
sufficient to explain most of the observed statistics. We show the predictive
power of such generative models in forecasting putative gene-disease
associations in the Online Mendelian Inheritance in Man (OMIM) database. The
approach is suitable for both directed and undirected uni-partite as well as
for bipartite networks
Hereditary angioedema: New therapeutic options for a potentially deadly disorder
Although the biochemistry of hereditary angioedema (HAE) is fairly well understood today, the lag in diagnosis of a decade or more suggests that clinicians have low awareness of this disease. This lag in diagnosis and hence treatment certainly stems from the rarity and complexity of the presentation which can be easily mistaken for allergic and non-allergic reactions alike. The symptoms of the disease include acute swelling of any or multiple parts of the body. The attacks may be frequent or rare, and they may vary substantially in severity, causing stomach discomfort or periorbital swelling in mild cases and hypovolemic shock due to abdominal fluid shift or asphyxiation in the most severe cases. Given that these patients are at significant risk for poor quality of life and death, greater awareness of this disease is needed to ensure that newly available, effective medications are used in these patients. These new medications represent significant advances in HAE therapy because they are targeted at the plasma cascades implicated in the pathophysiology of this disease. The clinical presentation of HAE, overlapping symptoms with other angioedemas, and available therapies are reviewed
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