513 research outputs found
Do cows see the forest or the trees? A preliminary investigation of attentional scope as a potential indicator of emotional state in dairy cows housed with their calves
Dairy cows housed both full- and part-time with their calves form strong maternal bonds
\ua9 2024 The Authors. Dairy cow and calf are typically separated shortly after calving preventing the formation of a maternal-filial bond. To allow some cow-calf contact, part-time contact during the first weeks is thought to be a feasible solution, but it is unknown if it weakens maternal bond, i.e., if maternal motivation is lower. This study aimed to investigate how different amounts of calf contact (full-time, part-time, and no contact) affect cowsâ maternal motivation. Using pneumatic push gates, we assessed cowsâ motivation to access their own calf using the maximum price paid (MPP) method. To mitigate frustration at high prices, cows could also access an unfamiliar calf at a constant low price. We expected that cows would access the unfamiliar calf when reaching the maximum price that they were motivated to pay to access their own calf. Following 48 h in a calving pen, cow-calf pairs were allocated to three different treatments: full-time (23 h contact/d, 28 pairs), part-time (10 h contact/d, 27 pairs), and no contact (0 h contact/d, 26 pairs). Approximately 40 d after calving, cows were trained to pass through each of two push gates: one leading to their own and one leading to an unfamiliar calf. The weight on the gate leading to the cowsâ own calf increased following each passing, while the gate leading to the unfamiliar calf remained light. Cows were tested once daily, until they failed to pass through the gate leading to their own calf on two consecutive days. MPP was analysed using a Cox\u27s proportional hazards mixed effects model. Fewer no-contact cows than full- and part-time cows fulfilled the learning criteria. Furthermore, no-contact cows paid a lower maximum price compared to the two contact treatments, while the MPP of full- and part-time cows did not differ. Most cows remained in the start box if they did not pass the gate to their own calf, indicating that an unfamiliar calf could not substitute for their own calf at high prices. We conclude that cows with part-time calf contact form a maternal bond of similar strength to cows with full-time calf contact. Additionally, cows separated from their calf at 48 h after calving have a weaker maternal motivation at 40 days postpartum
Reduction of carboplatin induced emesis by ondansetron.
Ondansetron is a selective 5-HT3 antagonist with significant antiemetic properties in patients receiving cytotoxic chemotherapy. Patients who had suffered severe vomiting on carboplatin alone (23 patients with ovarian carcinoma) or in combination (two patients with testicular cancer) despite intensive antiemetic regimens were treated with ondansetron, given as 8 mg immediately prior to carboplatin followed by 8 mg orally, 8 hourly for 5 days. Twenty-five patients received 58 courses of ondansetron. In the first 24 h after the first course of chemotherapy with ondansetron, 17 patients (68%) experienced no vomiting, five patients (20%) had almost complete control and the other three patients had partial control. During the subsequent 4 days slightly lesser control was achieved. Nausea was similarly controlled in most patients. Twenty-two patients stated a preference for ondansetron with future chemotherapy. Fourteen patients received additional chemotherapy with ondansetron and in only three patients did the efficacy of therapy lessen. Toxicity was mild and transient with headache and constipation predominant. No extrapyramidal reaction was seen. Sedation was absent. Ondansetron is highly effective in refractory vomiting associated with carboplatin chemotherapy. It may be particularly beneficial when an extrapyramidal reaction has occurred on previous antiemetics and when sedation is unacceptable
Analytical solution of generalized Burton--Cabrera--Frank equations for growth and post--growth equilibration on vicinal surfaces
We investigate growth on vicinal surfaces by molecular beam epitaxy making
use of a generalized Burton--Cabrera--Frank model. Our primary aim is to
propose and implement a novel analytical program based on a perturbative
solution of the non--linear equations describing the coupled adatom and dimer
kinetics. These equations are considered as originating from a fully
microscopic description that allows the step boundary conditions to be directly
formulated in terms of the sticking coefficients at each step. As an example,
we study the importance of diffusion barriers for adatoms hopping down
descending steps (Schwoebel effect) during growth and post-growth equilibration
of the surface.Comment: 16 pages, REVTeX 3.0, IC-DDV-94-00
Graph partitions and cluster synchronization in networks of oscillators
Synchronization over networks depends strongly on the structure of the coupling between the oscillators. When the coupling presents certain regularities, the dynamics can be coarse-grained into clusters by means of External Equitable Partitions of the network graph and their associated quotient graphs. We exploit this graph-theoretical concept to study the phenomenon of cluster synchronization, in which different groups of nodes converge to distinct behaviors. We derive conditions and properties of networks in which such clustered behavior emerges and show that the ensuing dynamics is the result of the localization of the eigenvectors of the associated graph Laplacians linked to the existence of invariant subspaces. The framework is applied to both linear and non-linear models, first for the standard case of networks with positive edges, before being generalized to the case of signed networks with both positive and negative interactions. We illustrate our results with examples of both signed and unsigned graphs for consensus dynamics and for partial synchronization of oscillator networks under the master stability function as well as Kuramoto oscillators
Hygge, Hope and Higher Education: A Case Study of Denmark
Higher education institutions have been profoundly reshaped by processes associated with neoliberalism. In this chapter, Larsen outlines the ways in which Denmark has ushered in marketdriven reforms to the Danish higher education system to enhance their institutional competitiveness over the past 30 years. Research on the impacts of neoliberal higher education reforms on faculty is reviewed and the author discusses her experiences (at a Canadian university) with market-driven, accountability reforms. The chapter shifts direction and provides the reader with an overview of the concept of hygge, an idealized Danish term that has connotations of coziness, safety, friendliness, and intimacy. Larsen recounts her experiences as a Canadian academic on sabbatical at a Danish university in 2017, illustrating the ways in which she experienced hygge in the Danish university setting. In the final section of the chapter, Larsen argues that hygge can be viewed as a retreat from the individualism, competition, market stratification and other challenges associated with neoliberalism. Hygge marks out the boundaries between the cold and heartless market-place and the warm and cozy home, and despite critiques that is instantiates exclusions, hygge offers hope to resist the alienation associated with neoliberalism and provide an alternative ethos for close and safe social relations within academia
Secondary school pupils' preferences for different types of structured grouping practices
The aim of this paper is to explore pupilsâ preferences for particular types of grouping practices an area neglected in earlier research focusing on the personal and social outcomes of ability grouping. The sample comprised over 5,000 year 9 pupils (aged 13-14 years) in 45 mixed secondary comprehensive schools in England. The schools represented three levels of ability grouping in the lower school (years 7 to 9). Pupils responded to a questionnaire which explored the types of grouping that they preferred and the reasons for their choices. The majority of pupils preferred setting, although this was mediated by their set placement, type of school, socio-economic status and gender. The key reason given for this preference was that it enabled work to be matched to learning needs. The paper considers whether there are other ways of achieving this avoiding the negative social and personal outcomes of setting for some pupils
Novel diffusion mechanism on the GaAs(001) surface: the role of adatom-dimer interaction
Employing first principles total energy calculations we have studied the
behavior of Ga and Al adatoms on the GaAs(001)-beta2 surface. The adsorption
site and two relevant diffusion channels are identified. The channels are
characterized by different adatom-surface dimer interaction. Both affect in a
novel way the adatom migration: in one channel the diffusing adatom jumps
across the surface dimers and leaves the dimer bonds intact, in the other one
the surface dimer bonds are broken. The two channels are taken into account to
derive effective adatom diffusion barriers. From the diffusion barriers we
conclude a strong diffusion anisotropy for both Al and Ga adatoms with the
direction of fastest diffusion parallel to the surface dimers. In agreement
with experimental observations we find higher diffusion barriers for Al than
for Ga.Comment: 4 pages, 2 figures, Phys. Rev. Lett. 79 (1997). Other related
publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm
Academic freedom in Europe: time for a Magna Charta?
This paper is a preliminary attempt to establish a working definition of academic freedom for the European Union states. The paper details why such a definition is required for the European Union and then examines some of the difficulties of defining academic freedom. By drawing upon experience of the legal difficulties beset by the concept in the USA and building on previous analyses of constitutional and legislative protection for academic freedom, and of legal regulations concerning institutional governance and academic tenure, a working definition of academic freedom is then derived. The resultant definition which, it is suggested, could form the basis for a European Magna Charta Libertatis Academicae, goes beyond traditional discussions of academic freedom by specifying not only the rights inherent in the concept but also its accompanying duties, necessary limitations and safeguards. The paper concludes with proposals for how the definition might be tested and carried forward
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