Sparse representation based action and gesture recognition

In this paper we present a solution to the problem of action and gesture recognition using sparse representations. The dictionary is modelled as a simple concatenation of features computed for each action or gesture class from the training data, and test data is classified by finding sparse representation of the test video features over this dictionary. Our method does not impose any explicit training procedure on the dictionary. We experiment our model with two kinds of features, by projecting (i) Gait Energy Images (GEIs) and (ii) Motion-descriptors, to a lower dimension using Random projection. Experiments have shown 100% recognition rate on standard datasets and are compared to the results obtained with widely used SVM classifier.

Optical imaging of postsynaptic odor representation in the glomerular layer of the mouse olfactory bulb.

Olfactory glomeruli are the loci where the first odor-representation map emerges. The glomerular layer comprises exquisite local synaptic circuits for the processing of olfactory coding patterns immediately after their emergence. To understand how an odor map is transferred from afferent terminals to postsynaptic dendrites, it is essential to directly monitor the odor-evoked glomerular postsynaptic activity patterns. Here we report the use of a transgenic mouse expressing a Ca(2+)-sensitive green fluorescence protein (GCaMP2) under a Kv3.1 potassium-channel promoter. Immunostaining revealed that GCaMP2 was specifically expressed in mitral and tufted cells and a subpopulation of juxtaglomerular cells but not in olfactory nerve terminals. Both in vitro and in vivo imaging combined with glutamate receptor pharmacology confirmed that odor maps reported by GCaMP2 were of a postsynaptic origin. These mice thus provided an unprecedented opportunity to analyze the spatial activity pattern reflecting purely postsynaptic olfactory codes. The odor-evoked GCaMP2 signal had both focal and diffuse spatial components. The focalized hot spots corresponded to individually activated glomeruli. In GCaMP2-reported postsynaptic odor maps, different odorants activated distinct but overlapping sets of glomeruli. Increasing odor concentration increased both individual glomerular response amplitude and the total number of activated glomeruli. Furthermore, the GCaMP2 response displayed a fast time course that enabled us to analyze the temporal dynamics of odor maps over consecutive sniff cycles. In summary, with cell-specific targeting of a genetically encoded Ca(2+) indicator, we have successfully isolated and characterized an intermediate level of odor representation between olfactory nerve input and principal mitral/tufted cell output.

Taxonomy development and knowledge representation of nurses' personal cognitive artifacts.

Nurses prepare knowledge representations, or summaries of patient clinical data, each shift. These knowledge representations serve multiple purposes, including support of working memory, workload organization and prioritization, critical thinking, and reflection. This summary is integral to internal knowledge representations, working memory, and decision-making. Study of this nurse knowledge representation resulted in development of a taxonomy of knowledge representations necessary to nursing practice.This paper describes the methods used to elicit the knowledge representations and structures necessary for the work of clinical nurses, described the development of a taxonomy of this knowledge representation, and discusses translation of this methodology to the cognitive artifacts of other disciplines. Understanding the development and purpose of practitioner's knowledge representations provides important direction to informaticists seeking to create information technology alternatives. The outcome of this paper is to suggest a process template for transition of cognitive artifacts to an information system.

Representation via Probabilities: Models of Probabilistic Modeling

How do probabilistic models represent their targets and how do they allow us to learn about them? The answer to this question depends on a number of details, in particular on the meaning of the probabilities involved. To classify the options, a minimalist conception of representation (Su\'arez 2004) is adopted: Modelers devise substitutes (``sources'') of their targets and investigate them to infer something about the target. Probabilistic models allow us to infer probabilities about the target from probabilities about the source. This leads to a framework in which we can systematically distinguish between different models of probabilistic modeling. I develop a fully Bayesian view of probabilistic modeling, but I argue that, as an alternative, Bayesian degrees of belief about the target may be derived from ontic probabilities about the source. Remarkably, some accounts of ontic probabilities can avoid problems if they are supposed to apply to sources only.

Representation Matters: The Impact of Descriptive Women's Representation on the Political Involvement of Women

In a cross-country comparison of 33 European countries, we tested whether a high degree of female representation attenuates the assumed negative impact of gender on political involvement. Our multilevel analyses show positive interactive effects of female representation: the degree to which the representation of women in a given country's national parliament was descriptively adequate was positively related to women's ratings of the importance of politics and self-reported political interest. With respect to political participation, the findings are mixed.

Mind the gap: Do proportional electoral systems foster a more equal representation of women and men, poor and rich?

Female gender and low income are two markers for groups that have been historically disadvantaged within most societies. The study explores two research questions related to their political representation: (1) ‘Are parties biased towards the ideological preferences of male and rich citizens?’; and (2) ‘Does the proportionality of the electoral system moderate the degree of under-representation of women and poor citizens in the party system?’ A multilevel analysis of survey data from 24 parliamentary democracies indicates that there is some bias against those with low income and, at a much smaller rate, women. This has systemic consequences for the quality of representation, as the preferences of the complementary groups differ. The proportionality of the electoral system influences the degree of under-representation: specifically, larger district magnitudes help in closing the considerable gap between rich and poor.

More Money, Fewer Problems? Cross-Level Effects of Economic Deprivation on Political Representation

While equal political representation of all citizens is a fundamental democratic goal, it is hampered empirically in a multitude of ways. This study examines how the societal level of economic inequality affects the representation of relatively poor citizens by parties and governments. Using CSES survey data for citizens’ policy preferences and expert placements of political parties, empirical evidence is found that in economically more unequal societies, the party system represents the preferences of relatively poor citizens worse than in more equal societies. This moderating effect of economic equality is also found for policy congruence between citizens and governments, albeit slightly less clear-cut.

Reassembling a system from the sensor to cerebral representation: the olfactory system in vitro.

An odorant's code is represented by activity in a dispersed ensemble of olfactory sensory neurons in the nose, activation of a specific combination of groups of mitral cells in the olfactory bulb and is considered to be mapped at divergent locations in the olfactory cortex. We present here an in vitro model of the mammalian olfactory system developed to gain easy access to all stations of the olfactory pathway. Mouse olfactory epithelial explants are cocultured with a brain slice that includes the olfactory bulb and olfactory cortex areas and maintains the central olfactory pathway intact and functional. Organotypicity of bulb and cortex is preserved and mitral cell axons can be traced to their target areas. Calcium imaging shows propagation of mitral cell activity to the piriform cortex. Long term coculturing with postnatal olfactory epithelial explants restores the peripheral olfactory pathway. Olfactory receptor neurons renew and progressively acquire a mature phenotype. Axons of olfactory receptor neurons grow out of the explant and rewire into the olfactory bulb. The extent of reinnervation exhibits features of a postlesion recovery. Functional imaging confirms the recovery of part of the peripheral olfactory pathway and shows that activity elicited in olfactory receptor neurons or the olfactory nerves is synaptically propagated into olfactory cortex areas. This model is the first attempt to reassemble a sensory system in culture, from the peripheral sensor to the site of cortical representation. It will increase our knowledge on how neuronal circuits in the central olfactory areas integrate sensory input and counterbalance damage.

Transgressive sporting bodies - A theoretical and critical dicourse analysis of the representation of Caster Semenya in Swiss print media

A debate about Caster Semenya's female sex began shortly after the South African runner won gold in the women’s 800m final at the 2009 Athletic World Championships held in Berlin. Her victory was disputed through questions about her right to compete as a ‘woman’, with the International Association of Athletics Federation (IAAF) announcing she would be required to undergo a gender verification test before her victory could be confirmed. Using the theoretical frame of social constructionism (Berger & Luckmann), poststructuralism (Foucault), gender- and postcolonial theories (Butler; Hall; Spivak) and the methodology of critical discourse analysis (Jaeger), the paper explores the way the possible intersexuality of Caster Semenya was contextualised in mainstream Swiss German-language print media. The analyses will firstly look at the way in which Caster Semenya was constructed as a ʻfallen hero’ and stigmatised as a double-dealer and unacceptable deviant body. The rumours amongst athletes and commentators became news in the media, which focused on descriptions of her habitus, her muscular body and her deep voice. Through theoretical discussion the paper argues that the media response to Caster Semenya exemplifies Butler’s claim that the discursive framework of gender constructs and naturalises sex. A key question is therefore whether the designation of deviant bodies to a ʻfield of deformation’ (Butler) works to pluralise the field of gender, or rather, as Butler suggests, it tends that those bodies might call into questions. The final part of the paper discusses how gender, ethnicity and sexuality combine to constitute the black female sporting body as a spectacle of otherness. It is evident that this otherness is made manifest through the function of those bodies as a site of transgression, as the boundary between male and female, and often as the boundary between culture and nature (Hall). Using the example of the controversy surrounding Caster Semenya, this paper aims to demonstrate how the post/colonial white female body is reproduced by western norms of gender, sexuality, beauty and sporting behaviour, in the sense of a feminine sporting genderperformance. The media controversy will be also read through the lens of the globalisation of certain ideas of normative bodies, sex, ethnicity and gender and the challenge of changing stereotypes through transgression. Keywords: gender- and postcolonial theories, discourse analysis, print media, Caster Semen-ya, deviant body, ethnicity, intersexuality

Transgressive sporting bodies - A theoretical and critical dicourse analysis of the representation of Caster Semenya in Swiss print media

A debate about Caster Semenya's female sex began shortly after the South African runner won gold in the women’s 800m final at the 2009 Athletic World Championships held in Berlin. Her victory was disputed through questions about her right to compete as a ‘woman’, with the International Association of Athletics Federation (IAAF) announcing she would be required to undergo a gender verification test before her victory could be confirmed. Using the theoretical frame of social constructionism (Berger & Luckmann), poststructuralism (Foucault), gender- and postcolonial theories (Butler; Hall; Spivak) and the methodology of critical discourse analysis (Jaeger), the paper explores the way the possible intersexuality of Caster Semenya was contextualised in mainstream Swiss German-language print media. The analyses will firstly look at the way in which Caster Semenya was constructed as a ʻfallen hero’ and stigmatised as a double-dealer and unacceptable deviant body. The rumours amongst athletes and commentators became news in the media, which focused on descriptions of her habitus, her muscular body and her deep voice. Through theoretical discussion the paper argues that the media response to Caster Semenya exemplifies Butler’s claim that the discursive framework of gender constructs and naturalises sex. A key question is therefore whether the designation of deviant bodies to a ʻfield of deformation’ (Butler) works to pluralise the field of gender, or rather, as Butler suggests, it tends that those bodies might call into questions. The final part of the paper discusses how gender, ethnicity and sexuality combine to constitute the black female sporting body as a spectacle of otherness. It is evident that this otherness is made manifest through the function of those bodies as a site of transgression, as the boundary between male and female, and often as the boundary between culture and nature (Hall). Using the example of the controversy surrounding Caster Semenya, this paper aims to demonstrate how the post/colonial white female body is reproduced by western norms of gender, sexuality, beauty and sporting behaviour, in the sense of a feminine sporting genderperformance. The media controversy will be also read through the lens of the globalisation of certain ideas of normative bodies, sex, ethnicity and gender and the challenge of changing stereotypes through transgression. Keywords: gender- and postcolonial theories, discourse analysis, print media, Caster Semen-ya, deviant body, ethnicity, intersexuality