2,496 research outputs found
Spectral plots and the representation and interpretation of biological data
It is basic question in biology and other fields to identify the char-
acteristic properties that on one hand are shared by structures from a
particular realm, like gene regulation, protein-protein interaction or neu- ral
networks or foodwebs, and that on the other hand distinguish them from other
structures. We introduce and apply a general method, based on the spectrum of
the normalized graph Laplacian, that yields repre- sentations, the spectral
plots, that allow us to find and visualize such properties systematically. We
present such visualizations for a wide range of biological networks and compare
them with those for networks derived from theoretical schemes. The differences
that we find are quite striking and suggest that the search for universal
properties of biological networks should be complemented by an understanding of
more specific features of biological organization principles at different
scales.Comment: 15 pages, 7 figure
Comparing the immune response to a novel intranasal nanoparticle PLGA vaccine and a commercial BPI3V vaccine in dairy calves
peer-reviewedBackground There is a need to improve vaccination against respiratory pathogens in calves by stimulation of local immunity at the site of pathogen entry at an early stage in life. Ideally such a vaccine preparation would not be inhibited by the maternally derived antibodies. Additionally, localized immune response at the site of infection is also crucial to control infection at the site of entry of virus. The present study investigated the response to an intranasal bovine parainfluenza 3 virus (BPI3V) antigen preparation encapsulated in PLGA (poly dl-lactic-co-glycolide) nanoparticles in the presence of pre-existing anti-BPI3V antibodies in young calves and comparing it to a commercially available BPI3V respiratory vaccine.
Results
There was a significant (P < 0.05) increase in BPI3V-specific IgA in the nasal mucus of the BPI3V nanoparticle vaccine group alone. Following administration of the nanoparticle vaccine an early immune response was induced that continued to grow until the end of study and was not observed in the other treatment groups. Virus specific serum IgG response to both the nanoparticle vaccine and commercial live attenuated vaccine showed a significant (P < 0.05) rise over the period of study. However, the cell mediated immune response observed didn’t show any significant rise in any of the treatment groups.
Conclusion
Calves administered the intranasal nanoparticle vaccine induced significantly greater mucosal IgA responses, compared to the other treatment groups. This suggests an enhanced, sustained mucosal-based immunological response to the BPI3V nanoparticle vaccine in the face of pre-existing antibodies to BPI3V, which are encouraging and potentially useful characteristics of a candidate vaccine. However, ability of nanoparticle vaccine in eliciting cell mediated immune response needs further investigation. More sustained local mucosal immunity induced by nanoparticle vaccine has obvious potential if it translates into enhanced protective immunity in the face of virus outbreak
Сутність та класифікація ризиків інвестиційної діяльності
Наводиться визначення поняттю "ризики інвестиційної діяльності" за рахунок поєднання його сутнісних характеристик, виконано узагальнення класифікації цих ризиків, запропоновано введення нової класифікаційної групи – "корпоративні ризики", які пов'язані з можливістю втрати контролю над підприємством інвестором-акціонером
Ectopic A-lattice seams destabilize microtubules
Natural microtubules typically include one A-lattice seam within an otherwise helically symmetric B-lattice tube. It is currently unclear how A-lattice seams influence microtubule dynamic instability. Here we find that including extra A-lattice seams in GMPCPP microtubules, structural analogues of the GTP caps of dynamic microtubules, destabilizes them, enhancing their median shrinkage rate by >20-fold. Dynamic microtubules nucleated by seeds containing extra A-lattice seams have growth rates similar to microtubules nucleated by B-lattice seeds, yet have increased catastrophe frequencies at both ends. Furthermore, binding B-lattice GDP microtubules to a rigor kinesin surface stabilizes them against shrinkage, whereas microtubules with extra A-lattice seams are stabilized only slightly. Our data suggest that introducing extra A-lattice seams into dynamic microtubules destabilizes them by destabilizing their GTP caps. On this basis, we propose that the single A-lattice seam of natural B-lattice MTs may act as a trigger point, and potentially a regulation point, for catastrophe
Recommended from our members
'Tipping the Balance': Karl Friedrich Meyer, Latent Infections, and the Birth of Modern Ideas of Disease Ecology
The Swiss-born medical researcher Karl Friedrich Meyer (1884–1974) is best known as a ‘microbe hunter’ who pioneered investigations into diseases at the intersection of animal and human health in California in the 1920s and 1930s. In particular, historians have singled out Meyer’s 1931 Ludwig Hektoen Lecture in which he described the animal kingdom as a ‘reservoir of disease’ as a forerunner of ‘one medicine’ approaches to emerging zoonoses. In so doing, however, historians risk overlooking Meyer’s other intellectual contributions. Developed in a series of papers from the mid-1930s onwards, these were ordered around the concept of latent infections and sought to link microbial behavior to broader bio-ecological, environmental, and social factors that impact hostpathogen interactions. In this respect Meyer—like the comparative pathologist Theobald Smith and the immunologist Frank Macfarlane Burnet—can be seen as a pioneer of modern ideas of disease ecology. However, while Burnet’s and Smith’s contributions to this scientific field have been widely acknowledged, Meyer’s have been largely ignored. Drawing on Meyer’s published writings and private correspondence, this paper aims to correct that lacuna while contributing to a reorientation of the historiography of bacteriological epidemiology. In particular I trace Meyer’s intellectual exchanges with Smith, Burnet and the animal ecologist Charles Elton, over brucellosis, psittacosis and plague—exchanges that not only showed how environmental and ecological conditions could ‘tip the balance’ in favor of parasites but which transformed Meyer thinking about resistance to infection and disease
Which symptoms are linked to a delayed presentation among melanoma patients? A retrospective study
Background: The incidence of melanoma is rising. Early detection is associated with a more favourable outcome. The factors that influence the timing of a patient’s presentation for medical assessment are not fully understood. The aims of the study were to measure the nature and duration of melanoma symptoms in a group of patients diagnosed with melanoma within the preceding 18 months and to identify the symptoms and barriers associated with a delay in presentation. Methods: A questionnaire was distributed to a random sample of 200 of the 963 melanoma patients who had participated in the Cancer Patient Experience Survey 2010 and were known to be alive 1 year later. Data were collected on symptoms, duration of symptoms prior to presentation and the reasons for not attending a doctor sooner. Results: A total of 159 patients responded to the questionnaire; 74 (47%) were men; mean age was 62 (range 24–90) years. Of the 149 patients who reported a symptom, 40 (27%) had a delayed presentation (i.e. >3 months). A mole growing bigger was the most common symptom and reporting this symptom was significantly associated with a delayed presentation (odds ratio (OR) 2.04, 95% confidence interval (95% CI) 1.14–5.08). Patients aged ≥65 years were less likely to report a barrier to presentation and were less likely to delay than those under 40, although this was of borderline statistical significance (OR 0.28, 95% CI 0.08–1.00). Conclusions: This study highlights that an enlarging mole is a significant symptom influencing the timing of presentation. Increasing public awareness of the signs of melanoma and of the importance of early presentation is desirable. Health professionals should take advantage of the opportunity to educate patients on such symptoms and signs where feasible. Further exploration of the barriers to presentation in younger people should be considered
Interested but not engaged: how Europe's media cover Brexit
How do European media cover Brexit? This study by the Reuters Institute for the Study of Journalism in cooperation with the media research specialist PRIME Research UK sheds some light on the intensity and focus media outlets in eight countries outside of the United Kingdom dedicate to the process of the UK’s leaving the European Union. The comparative content analysis examined the complete coverage of 39 media outlets in Ireland, Germany, France, Spain, Sweden, Italy, Greece and Poland over a period of seven months. It found that while the reporting was fairly stable in volume, it was rather dispassionate in tone. In most countries media regarded Brexit as a domestic challenge for the UK, not as a problem for the EU. The exception was Ireland, who is directly affected in many respects. Most coverage revolved either around the progress of the negotiations or centred on issues connected to the economy
Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions
The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions
Is gender encoded in the smile? A computational framework for the analysis of the smile driven dynamic face for gender recognition
YesAutomatic gender classification has become a topic of great interest to the visual computing research community in recent
times. This is due to the fact that computer-based automatic gender recognition has multiple applications including, but not
limited to, face perception, age, ethnicity, identity analysis, video surveillance and smart human computer interaction. In this
paper, we discuss a machine learning approach for efficient identification of gender purely from the dynamics of a person’s
smile. Thus, we show that the complex dynamics of a smile on someone’s face bear much relation to the person’s gender.
To do this, we first formulate a computational framework that captures the dynamic characteristics of a smile. Our dynamic
framework measures changes in the face during a smile using a set of spatial features on the overall face, the area of the
mouth, the geometric flow around prominent parts of the face and a set of intrinsic features based on the dynamic geometry
of the face. This enables us to extract 210 distinct dynamic smile parameters which form as the contributing features for
machine learning. For machine classification, we have utilised both the Support Vector Machine and the k-Nearest Neighbour
algorithms. To verify the accuracy of our approach, we have tested our algorithms on two databases, namely the CK+ and the
MUG, consisting of a total of 109 subjects. As a result, using the k-NN algorithm, along with tenfold cross validation, for
example, we achieve an accurate gender classification rate of over 85%. Hence, through the methodology we present here,
we establish proof of the existence of strong indicators of gender dimorphism, purely in the dynamics of a person’s smile
Managing Incidental Genomic Findings in Clinical Trials: Fulfillment of the Principle of Justice
<p>Managing Incidental Genomic Findings in Clinical Trials: Fulfillment of the Principle of Justice</p
- …
