Order and coherence in the fate map of the zebrafish nervous system

The zebrafish is an excellent vertebrate model for the study of the cellular interactions underlying the patterning and the morphogenesis of the nervous system. Here, we report regional fate maps of the zebrafish anterior nervous system at two key stages of neural development: the beginning (6 hours) and the end (10 hours) of gastrulation. Early in gastrulation, we find that the presumptive neurectoderm displays a predictable organization that reflects the future anteroposterior and dorsoventral order of the central nervous system. The precursors of the major brain subdivisions (forebrain, midbrain, hindbrain, neural retina) occupy discernible, though overlapping, domains within the dorsal blastoderm at 6 hours. As gastrulation proceeds, these domains are rearranged such that the basic order of the neural tube is evident at 10 hours. Furthermore, the anteroposterior and dorsoventral order of the progenitors is refined and becomes aligned with the primary axes of the embryo. Time-lapse video microscopy shows that the rearrangement of blastoderm cells during gastrulation is highly ordered. Cells near the dorsal midline at 6 hours, primarily forebrain progenitors, display anterior-directed migration. Cells more laterally positioned, corresponding to midbrain and hindbrain progenitors, converge at the midline prior to anteriorward migration. These results demonstrate a predictable order in the presumptive neurectoderm, suggesting that patterning interactions may be well underway by early gastrulation. The fate maps provide the basis for further analyses of the specification, induction and patterning of the anterior nervous system, as well as for the interpretation of mutant phenotypes and gene-expression patterns

More on pejorative language: insults that go beyond their extension

Slurs have become a big topic of discussion both in philosophy and in linguistics. Slurs are usually characterised as pejorative terms, co-extensional with other, neutral, terms referring to ethnic or social groups. However, slurs are not the only ethnic/social words with pejorative senses. Our aim in this paper is to introduce a different kind of pejoratives, which we will call “ethnic/social terms used as insults”, as exemplified in Spanish, though present in many other languages and mostly absent in English. These are ethnic terms like gitano, ‘Romani’, which can have an extensional and neutral use, but also a pejorative meaning building on a negative stereotypical representation of the Romani community

The literal/non-literal divide synchronically and diachronically: The lexical semantics of an English posture verb

This thesis' main research goal is to provide an account of the English posture verb sit, from a synchronic a diachronic perspective. My proposed account of sit comprises various components, including a characterisation of the different possible meanings of sit and a comparison with stand and lie. The two relevant meanings are a literal one and non-literal one (The girl is sitting on the chair vs. The wine bottle is sitting on the chair; in the former the subject is described to be in a sitting position, while in the latter the subject is not in a sitting position). I analyse each meaning/use separately, noting which semantic patterns occur with one type only and those which occur with both. I argue that the non-literal use is diachronically connected to the literal one, and I motivate this claim based on the shared components identified in the thesis and on data from corpus studies reported in the thesis. A consequence of acknowledging a divide between the literal and non-literal uses---a perspective not usually taken in theoretical linguistics---is that I am able to account for important semantic details which might be otherwise overlooked. The cognitive and typological literature includes account of posture verbs cross-linguistically, but in the theoretical literature these verbs have not received much attention. In this thesis, I review existing proposals and highlight the uncertainties surrounding the posture verbs. In order to fillthese gaps in the literature and to better understand the phenomena, I analyse data from synchronic and diachronic corpus studies, and incorporate these insights into my account of sitEl principal objetivo de investigación de esta tesis es dar cuenta del verbo de postura inglés sit (`sentarse¿), desde una perspectiva sincrónica y diacrónica. La descripción que propongo de sit comprende varios componentes, incluida una caracterización de los diferentes significados posibles de sit y una comparación con stand (`estar de pie¿) y lie (`estar echado¿). La literatura cognitiva y tipológica incluye una descripción de los verbos de postura de forma interlingüística, pero en la literatura teórica estos verbos no han recibido mucha atención. En esta tesis, reviso las propuestas existentes y destaco las preguntas sin responder que rodean a los verbos de postura. Para llenar estos vacíos en la literatura científica y comprender mejor los fenómenos, analizo datos de estudios de corpus sincrónicos y diacrónicos, e incorporo estos conocimientos en mi explicación de sit. Los dos significados relevantes son uno literal y uno no literal (The girl is sitting on the chair `La niña está sentada en la silla' vs. The wine bottle is sitting on the chair `(lit.) La botella de vino está sentada en la silla¿; en la primera frase, se describe el sujeto en posición de estar sentado, mientras que en la segunda frase el sujeto no está sentado). Analizo cada significado/uso por separado, notando qué patrones semánticos ocurren con un solo tipo y cuáles ocurren con ambos. Argumento que el uso no literal está conectado diacrónicamente con el literal, y motivo esta afirmación a partir de los componentes compartidos identificados en la tesis y en los datos de los estudios de corpus tratados en la tesis. Una consecuencia de reconocer una división entre los usos literales y no literales (una perspectiva que no suele adoptarse en la lingüística teórica) es que se consigue dar cuenta de importantes detalles semánticos que de otro modo podrían pasarse por alto

Perceptions of on-farm emergency slaughter for dairy cows in British Columbia

Some jurisdictions permit on-farm emergency slaughter (OFES) as one end-of-life option for dairy cows and other animals that cannot be transported humanely but are deemed fit for human consumption. Anecdotal reports suggest that OFES is controversial among dairy industry professionals, but to date their perceptions of OFES have not been studied systematically. Twentyfive individual interviews and 3 focus groups with 40 dairy producers, veterinarians, and other professionals in British Columbia, Canada, revealed positive and negative perceptions of OFES influenced by (1) individual values, (2) the perceived operational legitimacy of OFES, and (3) concern over social responsibility and public perception of the dairy industry. Study participants valued cow welfare but were divided on whether OFES quickened or delayed death for injured animals. Views on the operational legitimacy of OFES varied because of different perceptions and concerns regarding regulatory, veterinary, and meat inspector oversight, a possible conflict of interest for veterinarians, and concerns over carcass hygiene and transport. Whereas many appreciated that OFES prevented transport of compromised cows, others saw OFES as merely a stopgap measure. Seven recommended actions could address concerns while retaining the benefits of OFES: (1) specifying precise timing parameters for OFES, (2) clarification of allowable cow conditions for OFES, (3) consultation with dairy industry professionals if OFES is to be expanded, (4) more proactive culling and the development of euthanasia protocols on farms, (5) the designation of veterinarians as the first point of contact in the OFES process, (6) veterinarian training on animal inspection and allowable conditions for OFES, and (7) the use of proper procedures and equipment during the OFES process to ensure food safety

Use of on-farm emergency slaughter for dairy cows in British Columbia

On-farm emergency slaughter (OFES), whereby inspection, stunning, and bleeding occur on the farm before the carcass is transported to a slaughterhouse, is permitted in some jurisdictions as a means to avoid inhumane transportation while salvaging meat from injured animals. However, OFES is controversial and its use for dairy cows has been little studied. Inspection documents for 812 dairy cows were examined to identify how OFES was used for dairy cows in British Columbia, Canada, over 16.5 mo. Producers used OFES for dairy cows aged 1 to 13 yr (median of 4 yr). Leg, hip, nerve, spinal, foot, and hind-end injuries or conditions (in that order) were the most common reasons for OFES, and some cases may have been a consequence of calv-ing. Foot conditions were disproportionately common among cows 5 yr and older, and hind-end conditions were disproportionately common among cows 6 yr and older. Producers used OFES promptly after traumatic injury (within 1 d) for some cows, but OFES was de-layed for others, sometimes until cows had been nonam-bulatory for 2 to 6 d. In some cases, OFES was used for nontraumatic chronic conditions, such as lameness and hind-end weakness, rather than traumatic injuries such as fractures and dislocated hips. Use of OFES appears to conform to the purpose of the program when used promptly after traumatic injuries, but clear guidelines are needed to avoid inappropriate use and delays that may prolong animal suffering

Undergraduate students\u27 attitudes and perceptions towards a possibly coercive sexual encounter

This research addressed undergraduate students\u27 current attitudes and perceptions regarding a possibly coercive sexual encounter and the use of date rape drugs. A sample of undergraduate students from a Southern California university was surveyed. Attitudes and perceptions were examined using a self-administered survey in a classroom setting

Local, but not long-distance dispersal of penguin ticks between two sub-Antarctic islands

Advances in high throughput genomic approaches are enabling the accurate appraisal of movements of diverse species, previously considered intractable. The impact of long-distance dispersal and distribution changes on species interactions (such as host-parasite interactions) is of particular importance as attempts are made to project how ecosystems will shift under environmental change. The sub-Antarctic region, comprising isolated islands separated by hundreds to thousands of kilometres of open ocean, presents an ideal model system for studying long-distance dispersal, distribution, and ecosystem change. Here we used genomic methods to determine the extent of movement of penguin ticks (Ixodes uriae) among different host species, and among penguin colonies at small (within an island) and large (among islands separated by >6000 km) scales, in the sub-Antarctic region. Our results suggest that I. uriae ticks may be readily shared between distantly related penguin species with similar phenology, but indicate that – as inferred by previous research – ticks are less likely to be shared between flighted and non-flighted sea- birds. We also find evidence for small-scale movements of penguin ticks with their hosts, but no evidence for movements between islands separated by thousands of kilometers of open ocean. These inferred limitations to penguin tick movement could be the result of restricted host movements or the inability of penguin ticks to survive extended trips at sea. Our findings help elucidate parasite-host dynamics, with implications for host health and persistence in a region experiencing rapid environmental change