Stability, Electronic Structure and Vibrational Modes of Ti_8C_12 Dimer

We present our density functional results of the geometry, electronic structure and dissociation energy of Ti_8C_12 dimer. We show that as opposed to the currently held view that Ti_8C_12 are highly stable monodispersed clusters, the neutral Ti_8C_12 clusters form covalent bonds and form stable dimers. We determine that the Ti atoms bond weakly (0.9 eV/bond) to organic ligands such as ammonia. Alternatively the Met-Car dimer has a cohesive energy of 4.84 eV or approximately 1.2 eV per bond. While Met-Car dimers are stable, formation of these dimers may be quenched in an environment that contains a significant population of organic ligands. The ionization and dissociation energies of the dimer are of same order which prevents the observation of the dimer in the ion mass spectroscopy. The analysis of the vibrational frequencies show the lowest-energy structure to be dynamically stable. We also present infrared absorption and Raman scattering spectra of the Ti_8C_12 dimer.Comment: 5 pages, 3 figures (Better quality figures available on request). Physical Review B (Rapid Communication) (2002, in press

Mio-Pliocene Faunal Exchanges and African Biogeography: The Record of Fossil Bovids

The development of the Ethiopian biogeographic realm since the late Miocene is here explored with the presentation and review of fossil evidence from eastern Africa. Prostrepsiceros cf. vinayaki and an unknown species of possible caprin affinity are described from the hominid-bearing Asa Koma and Kuseralee Members (∼5.7 and ∼5.2 Ma) of the Middle Awash, Ethiopia. The Middle Awash Prostrepsiceros cf. vinayaki constitutes the first record of this taxon from Africa, previously known from the Siwaliks and Arabia. The possible caprin joins a number of isolated records of caprin or caprin-like taxa recorded, but poorly understood, from the late Neogene of Africa. The identification of these two taxa from the Middle Awash prompts an overdue review of fossil bovids from the sub-Saharan African record that demonstrate Eurasian affinities, including the reduncin Kobus porrecticornis, and species of Tragoportax. The fossil bovid record provides evidence for greater biological continuity between Africa and Eurasia in the late Miocene and earliest Pliocene than is found later in time. In contrast, the early Pliocene (after 5 Ma) saw the loss of any significant proportions of Eurasian-related taxa, and the continental dominance of African-endemic taxa and lineages, a pattern that continues today

Making sense of the evolving nature of depression narratives and their inherent conflicts

Originally a psychiatric diagnosis fashioned by Western psychiatry in the 20th Century, depression evolved to encompass varying lineages of discourse and care. This article elucidates some of the current challenges – as well as emerging discourses – influencing the category of depression. Depression-like experiences are shaped by (at times conflicting) subjectivities, claims to knowledge, material realities, social contexts and access to resources. With no unified understanding of the category of ‘depression’ available, lay people, social and neuro scientists, GPs, psychiatrists, talking therapists and pharmaceutical companies all attempt to shape narratives of depression. The current paper focuses on patient narratives about depression – in the context of these wider debates – to better elucidate the ways in which depression discourses are publically developing along varying lines. In conclusion, the paper suggests that we could better conceptualise the resulting ‘depression(s)’ with concepts such as ‘society of mind’ and notions of subjectivity unbounded by individuals

Exploring men's and women's experiences of depression and engagement with health professionals: more similarities than differences? A qualitative interview study

<p>Abstract</p> <p>Background</p> <p>It is argued that the ways in which women express emotional distress mean that they are more likely to be diagnosed with depression, while men's relative lack of articulacy means their depression is hidden. This may have consequences for communicating with health professionals. The purpose of this analysis was to explore how men and women with depression articulate their emotional distress, and examine whether there are gender differences or similarities in the strategies that respondents found useful when engaging with health professionals.</p> <p>Methods</p> <p>In-depth qualitative interviews with 22 women and 16 men in the UK who identified themselves as having had depression, recruited through general practitioners, psychiatrists and support groups.</p> <p>Results</p> <p>We found gender similarities and gender differences in our sample. Both men and women found it difficult to recognise and articulate mental health problems and this had consequences for their ability to communicate with health professionals. Key gender differences noted were that men tended to value skills which helped them to talk while women valued listening skills in health professionals, and that men emphasised the importance of getting practical results from talking therapies in their narratives, as opposed to other forms of therapy which they conceptualised as 'just talking'. We also found diversity among women and among men; some respondents valued a close personal relationship with health professionals, while others felt that this personal relationship was a barrier to communication and preferred 'talking to a stranger'.</p> <p>Conclusion</p> <p>Our findings suggest that there is not a straightforward relationship between gender and engagement with health professionals for people with depression. Health professionals need to be sensitive to patients who have difficulties in expressing emotional distress and critical of gender stereotypes which suggest that women invariably find it easy to express emotional distress and men invariably find it difficult. In addition it is important to recognise that, for a minority of patients, a personal relationship with health professionals can act as a barrier to the disclosure of emotional distress.</p

Indraloris And Sivaladapis - Miocene Adapid Primates From The Siwaliks Of India And Pakistan

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62538/1/279415a0.pd