1,393 research outputs found
The 1981 Springbok Tour and the anti-apartheid movement in Palmerston North : a research exercise completed in partial fulfilment of the requirements of the Batchelor of Arts with Honours at Massey University
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Electronic orders near the type-II van Hove singularity in BC
Using the functional renormalization group, we investigate the electron
instability in the single-sheet BC when the electron filling is near a
type-II van Hove singularity. For a finite Hubbard interaction, the
ferromagnetic-like spin density wave order dominates in the immediate vicinity
of the singularity. Elsewhere near the singularity the p-wave superconductivity
prevails. We also find that a small nearest-neighbor Coulomb repulsion can
enhance the superconductivity. Our results show that BC would be a
promising candidate to realize topological superconductivity, but the
transition temperature is practically sizable only if the local interaction is
moderately strong.Comment: 6 pages, 6 color figures. arXiv admin note: text overlap with
arXiv:1503.0047
Fermentation of animal components in strict carnivores: a comparative study with cheetah fecal inoculum
The natural diet of felids contains highly digestible animal tissues but also fractions resistant to small intestinal digestion, which enter the large intestine where they may be fermented by the resident microbial population. Little information exists on the microbial degradability of animal tissues in the large intestine of felids consuming a natural diet. This study aimed to rank animal substrates in their microbial degradability by means of an in vitro study using captive cheetahs fed a strict carnivorous diet as fecal donors. Fresh cheetah fecal samples were collected, pooled, and incubated with various raw animal substrates (chicken cartilage, collagen, glucosamine-chondroitin, glucosamine, rabbit bone, rabbit hair, and rabbit skin; 4 replicates per substrate) for cumulative gas production measurement in a batch culture technique. Negative (cellulose) and positive (casein and fructo-oligosaccharides; FOS) controls were incorporated in the study. Additionally, after 72 h of incubation, short-chain fatty acids (SCFA), including branched-chain fatty acids (BCFA), and ammonia concentrations were determined for each substrate. Glucosamine and glucosamine-chondroitin yielded the greatest OM cumulative gas volume (OMCV) among animal substrates (P < 0.05), whereas total SCFA production was greatest for collagen (P < 0.05). Collagen induced an acetate production comparable to FOS and a markedly high acetate-to-propionate ratio (8.41:1) compared to all other substrates (1.67:1 to 2.97:1)
The nature of aquatic landscapes in the Miocene of western Amazonia: An integrated palaeontological and geochemical approach
The Miocene Pebas Formation from the section Santa Rosa de Pichana (Loreto, Peru) was investigated using a combination of analyses of sedimentary facies, molluscan communities and taphonomy, and stable isotopes of both entire shells and growth bands in bivalves. Three sequences, comprising a succession of transgressive, maximum flooding and regressive/prograding intervals, are documented. Molluscs are most common in the transgressive/highstand intervals and are almost absent in regressive/prograding intervals. The fauna is dominated by endemic Pebasian species, such as Pachydon and Dyris spp. The nature of the deposits as well as the availability of oxygen varied in a predictable way within each of the sequences and determined the nature of the assemblages. Highest diversity was reached in the late transgressive phase before the development of dysoxia that was widespread during the late highstand and early regressive/prograding phase. The mollusc and isotope data show no indications of elevated salinities, in contrast to ichnofossils found in the section. This discrepancy is interpreted to result either from temporal separation of the ichnofossils and the mollusc fossils or from evolution beyond usual ecological tolerances of taxa that produced these ichnofossils into freshwater settings
A case for biotic morphogenesis of coniform stromatolites
Mathematical models have recently been used to cast doubt on the biotic
origin of stromatolites. Here by contrast we propose a biotic model for
stromatolite morphogenesis which considers the relationship between upward
growth of a phototropic or phototactic biofilm () and mineral accretion
normal to the surface (). These processes are sufficient to account
for the growth and form of many ancient stromatolities. Domical stromatolites
form when is less than or comparable to . Coniform structures with
thickened apical zones, typical of Conophyton, form when . More
angular coniform structures, similar to the stromatolites claimed as the oldest
macroscopic evidence of life, form when .Comment: 10 pages, 3 figures, to appear in Physica
Fast evaluation of appointment schedules for outpatients in health care
We consider the problem of evaluating an appointment schedule for outpatients in a hospital. Given a fixed-length session during which a physician sees K patients, each patient has to be given an appointment time during this session in advance. When a patient arrives on its appointment, the consultations of the previous patients are either already finished or are still going on, which respectively means that the physician has been standing idle or that the patient has to wait, both of which are undesirable. Optimising a schedule according to performance criteria such as patient waiting times, physician idle times, session overtime, etc. usually requires a heuristic search method involving a huge number of repeated schedule evaluations. Hence, the aim of our evaluation approach is to obtain accurate predictions as fast as possible, i.e. at a very low computational cost. This is achieved by (1) using Lindley's recursion to allow for explicit expressions and (2) choosing a discrete-time (slotted) setting to make those expression easy to compute. We assume general, possibly distinct, distributions for the patient's consultation times, which allows us to account for multiple treatment types, as well as patient no-shows. The moments of waiting and idle times are obtained. For each slot, we also calculate the moments of waiting and idle time of an additional patient, should it be appointed to that slot. As we demonstrate, a graphical representation of these quantities can be used to assist a sequential scheduling strategy, as often used in practice
Analysis of a spatial gene expression database for sea anemone Nematostella vectensis during early development
International audienceThe spatial distribution of many genes has been visualized during the embryonic development in the starlet sea anemone Nematostella vectensis in the last decade. In situ hybridization images are available in the Kahi Kai gene expression database, and a method has been developed to quantify spatial gene expression patterns of N. vectensis. In this paper, gene expression quantification is performed on a wide range of gene expression patterns from this database and descriptions of observed expression domains are stored in a separate database for further analysis
Risk factors for septic arthritis in patients with joint disease: A prospective study
Objective. To quantify potential risk factors for septic arthritis, in order to identify a basis for prevention.
Methods. The occurrence of potential risk factors for septic arthritis in patients with joint diseases attending a rheumatic disease clinic was prospectively monitored at 3-m onth intervals over a period of 3 years. Potential risk factors investigated were type of joint disease, comorbidity, medication, joint prosthesis, infections, and invasive procedures. The frequencies of risk factors in patients with and those without septic arthritis were compared using multiple logistic regression analysis.
Results. There were 37 patients with and 4,870 without septic arthritis. Risk factors for developing septic arthritis were age ≥80 years (odds ratio [OR] = 3.5, 95% confidence interval [95% CI] 1.4–8.6), diabetes mellitus (OR = 3.3, 95% CI 1.1–10.1), rheumatoid arthritis (OR = 4.0, 95% CI 1.9–8.3), hip and/or knee prosthesis (OR = 15, 95% CI 4.1–54.3), joint surgery (OR = 5.1, 95% CI 2.2–11.9), and skin infection (OR = 27.2, 95% CI 7.6–97.1)
Conclusion. These findings indicate that preventive measures against septic arthritis in patients with joint diseases should mainly be directed at those with joint prostheses and/or skin infection
Integration of anatomical and hemodynamical information in magnetic resonance angiography
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