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An assessment is presented of the extent and variability of Antarctic sea ice in the non-flux-corrected version of the Hadley Centre’s coupled atmosphere-ocean general circulation model (HadCM3). The results are based on a 100 year segment of a long control run of the model with the sea ice being compared to ice extents and concentrations derived from passive microwave satellite data. Over the year as a whole, the model ice extent (the area with >15% ice concentration) is 91% of that determined from satellite imagery, but, not surprisingly, the regional-scale distribution differs from the observed. Throughout the year there is too much ice near 90° E, which is believed to be present as a result of incorrect ocean currents near Kerguelen. In contrast to the satellite data, there is too little ice to the west of the Antarctic Peninsula as a result of anomalously northerly atmospheric flow, compared to observations. During the winter the sea-ice concentrations in the model are too high, possibly as a result of the simple representation of the sea ice, which does not simulate complex dynamical interactions within the pack. The annual cycle of sea-ice advance/retreat in the model has a phase error, with the winter sea-ice maximum extent being too late by about 1 month.
Scientific observations of sea ice began more than a century ago, but detailed sea-ice models appeared only in the latter half of the last century. The high albedo of sea ice is critical for the Earth’s heat balance, and ice motion across the ocean’s surface transports fresh water and salt. The basic components in a complete sea-ice model must include vertical thermodynamics and horizontal dynamics, including a constitutive relation for the ice, advection and deformational processes. This overview surveys topics in sea-ice modeling from the global climate modeling perspective, emphasizing work that significantly advanced the state of the art and highlighting promising new developments.
A survey of icebergs using satellite radar images has been made in the seasonal sea-ice zone of East Antarctica in the .sector between longitudes 50° and 145° E. These data provide information on the spatial distribution and size statistics of icebergs near the coast in areas not often visited by shipboard observers, and close to their sources at ice shelves and glacier tongues. The icebergs are detected and their dimensions extracted by analysis of the texture properties present in satellite images acquired with ERS-1 synthetic aperture radar during the austral winter. The minimum size of iceberg reliably detected and measured is 0.06 km2.
A significant variation, by up to a factor of two, is found in the area of icebergs close to different sections of the coast, which suggests a characteristic size for different sources. The average value of the length-to-width ratio for icebergs in the whole population shows some variability with size. The probability of finding icebergs is greatest close to the coast, decreasing in general with distance from the coast, such that few icebergs were detected more than 160 km from the coast. in one sector about 85° E, icebergs are found to at least 550 km from the coast, which is consistent with the transport of icebergs northwards in this region by a branch of the westward-heading near-coastal current (East Wind Drift) which connects with the southern margins of the eastward-heading Antarctic Circumpolar Current.
In this study we correlate temporal features within the electrical conductivity (acidity) traces of four shallow firn cores obtained from the southern Antarctic Peninsula to synoptic-scale variations in the regional climate, as depicted by a numerical weather prediction model. It is demonstrated that the three high-acidity features present within the 1992-93 accumulation correspond to periods of significant precipitation, a hypothesis supported by the association of these events with strong onshore winds, ideal for transporting the biogenically derived sources of precipitation acidity to the core sites. The longitudinal location of depressions within the Bellingshausen Sea is shown to be the principal factor governing the volume of precipitation that they give over the western Peninsula. Annual accumulation in the model is ~25% lower than revealed by the cores; although there are too many uncertainties to provide a definite reason for the deviation, the smoothed model orography and inaccurate land-sea mask are believed to be significant factors. It is postulated that the acidity pattern within southern Peninsula cores may reveal an El Niño-Southern Oscillation signal.
Background: Cognitive Behavioural Therapy (CBT) aims to teach people skills to help them self-manage their depression. Trial evidence shows that CBT is an effective treatment for depression and individuals may experience benefits long-term. However, there is little research about individuals’ continued use of CBT skills once treatment has finished. Aims: To explore whether individuals who had attended at least 12 sessions of CBT continued to use and value the CBT skills they had learnt during therapy. Method: Semi-structured interviews were held with participants from the CoBalT trial who had received CBT, approximately 4 years earlier. Interviews were audio-recorded, transcribed and analysed thematically. Results: 20 participants were interviewed. Analysis of the interviews suggested that individuals who viewed CBT as a learning process, at the time of treatment, recalled and used specific skills to manage their depression once treatment had finished. In contrast, individuals who viewed CBT only as an opportunity to talk about their problems did not appear to utilize any of the CBT skills they had been taught and reported struggling to manage their depression once treatment had ended. Conclusions: Our findings suggest individuals may value and use CBT skills if they engage with CBT as a learning opportunity at the time of treatment. Our findings underline the importance of the educational model in CBT and the need to emphasize this to individuals receiving treatment.
From June 15 to 28, 1991 the Compton Gamma-Ray Observatory (CGRO) observed the radio-loud quasar 3C 273. All four CGRO instruments detected radiation from this quasar in their relevant energy range (from 20 keV to 5 GeV). Simultaneous and quasi-simultaneous observations (spanning the time period May 27 – July 25, 1991) by instruments sensitive at other wavelengths have also been obtained. The data from all these observations spanning the frequency range from ∼ 109 Hz to ∼ 1026 Hz were collected and analysed. The resulting energy-density spectrum is shown in the figure below. It shows two maxima, one in the UV, another one at low-energy γ-rays which have nearly the same strength (the corresponding luminosities per decade of frequency for H0 = 60(km/s)/Mpc are 3.2·1046 erg/s and 2.7·1046 erg/s, respectively). A break of the spectrum at low-energy γ-rays is evident. From a detailed analysis a break energy of (2±1.5) MeV could be derived corresponding to a frequency of (4.8±3.6)·1020 Hz. The observed spectral break between X- and γ-rays is ∼ 0.8, much higher than the value of 0.5 predicted by some models. A more detailed paper on this topic is in preparation (Lichti et al.).
A small number of Wolf-Rayet colliding-wind binaries studied at extremely high angular resolution show elegant dust plumes with an intuitive geometry: that of an Archimedian spiral. A great deal of fundamental information on the binary and the winds is encoded, ultimately teaching us about dust formation and wind-wind collision zones in these fascinating systems. New results are presented summarizing a concerted campaign encompassing a number of systems studied with various techniques over the last five years.
Background: Cognitive behaviour therapy (CBT) for patients with treatment-resistant depression (TRD) aims to reframe underlying conditional beliefs that are thought to maintain depression. Aim: To systematically explore conditional beliefs expressed by primary-care based patients with TRD, defined as non-response to at least 6 weeks of antidepressants. Method: Conditional beliefs (stated in an “If. . .then. . .” format) were extracted from a random sample of 50 sets of therapist notes from the CoBalT trial, a large randomized controlled trial of CBT for TRD in primary care. The beliefs were separated into their two constituent parts; the demands (Ifs) and consequences (thens). An approach based on framework analysis provided a systematic way of organizing the data, and identifying key themes. Results: Four main themes emerged from the demand part of the conditional beliefs (Ifs): 1. High standards; 2. Putting others first/needing approval; 3. Coping; and 4. Hiding “true” self. Three main themes emerged from the consequence part of the conditional beliefs (thens): 1. Defectiveness; 2. Responses of others; 3. Control of emotions. Conclusions: Identifying common themes in the conditional beliefs of patients with TRD adds to our clinical understanding of this client group, providing useful information to facilitate the complex process of collaborative case conceptualization and working with conditional beliefs within CBT interventions.
The author, in the first instance, directed attention to the discrepant statements of various comparative anatomists respecting the thyroid gland in the Cetacea, quoting from the writings of John Hunter, Meckel, Cuvier, Carus, and Dr Martyn. He then related the result of his own dissections made on three specimens of the common porpoise (Phocœna communis), one being a fœtus, another a well grown male, the third an adult male. In each of these animals a well marked thyroid gland was found, lying on the anterior and lateral surfaces of the trachea at its upper end, and extending slightly upwards on each side over the outer surface of the cricoid cartilage. It presented no division into two lateral lobes, as described by Cuvier and Carus, but consisted of a single uniform mass extending across the middle line.
Comparative anatomists have of late directed considerable attention to the determination of the relations of the cerebrum and cerebellum. This has been in great measure due to the publication by Professor Owen of a system of classification of the Mammalia founded on their cerebral characters. The statement made by that eminent anatomist, that the posterior, or third, lobe of the cerebrum is peculiar and common to the genus Homo, and that equally peculiar are the “posterior horn of the lateral ventricle” and the “hippo-campus minor,” which characterise the hind lobe, has led to much discussion. Various anatomists have published descriptions and drawings of dissections of the brains of many of the Quadrumana, especially of several of the higher apes.
The authors, after a brief historical introduction, proceeded to give a detailed account of the anatomy of this parasitic crustacean, the description comprising that of the female and male, and, so far as they had been enabled to trace it, of the larva also.
The author obtained the pancreatic secretion at a post-mortem examination which he made of the body of a patient of Mr Spence's, who had died with a medullary tumour in the head of the pancreas, which, by compressing the biliary and pancreatic ducts, had produced dilatation of the ducts of the liver and gall-bladder, as well as dilatation of the ducts and lobules of the pancreas. The secretion was contained in the dilated parts of the gland last named, from which it was drawn off by means of a pipette. The fluid thus obtained was of an orange-yellow colour, and well-marked viscid consistency—sp. gr. 1·0105; appearance slightly turbid, owing to the presence of small white flakes, which a microscopic examination proved to consist of groups of small spherical, colourless cells, resembling, and most probably consisting of, the epithelial lining of the vesicles of the gland.
In this chapter Mike Axtell and William Turner describe how they went about undertaking, as novices, a literature review in mathematics education. Their experience revealed to them the critical role that the literature review can play in refining a SoTL research question and how it can aid in designing a study. Readers may want to contrast their study of reading questions with that written by Derek Bruff in the preceding chapter.
We begin by providing the background of our investigation. We describe what motivated us to use pre-class reading assignments and how over time we developed a system that involved not just assigned readings but reading questions (RQs) as well. We explain why we decided to investigate their use and what it was that we wanted to know, at first.
The process of reading a mathematical text and understanding it is complicated and difficult (Konior, 1993; Reiter, 1998). It is an acquired skill that few, if any, come by naturally. However, it is one that mathematicians must learn. Mathematics conferences and pedagogical publications often contain ideas on how to get, or teach, students to read mathematics (Amick, 1997; Gold, 1998; King, 2001; Ratliff, 1998; Reiter, 1998; Taalman, 1998), and there are hundreds of references on how to help students improve their critical reading skills (Bratina & Lipkin, 2003). The goal is for students to become independent learners capable of teaching themselves, perhaps the ultimate goal of any liberal education program.
If we as teachers are convinced of the need to get students to read a mathematical text, we should then be concerned with determining what our students are gaining, and not gaining, from this task. If our strategies are not leading to desired outcomes, then we should rethink them. This observation led us to collaborate on a SoTL project during the 2005-2006 academic year that focused on student reading.
Since the discovery in 1989 that mutations in cystic fibrosis transmembrane conductance regulator (CFTR) underlie cystic fibrosis (CF), the most common life shortening genetic disorder in Caucasians, it has been possible to identify heterozygous mutation carriers at risk of having affected children. The Human Genetics Society of Australasia has produced a position statement with recommendations in relation to population-based screening for CF. These include: (1) that screening should be offered to all relatives of people with or carriers of CF (cascade testing) as well as to all couples planning to have children or who are pregnant; (2) the minimum CFTR mutation panel to be tested consists of 17 mutations which are those mutations that are associated with typical CF and occur with a frequency of 0.1% or higher among individuals diagnosed with CF in Australasia; (3) that genetic counselling is offered to all couples where both members are known to have one or two CFTR mutations and that such couples are given the opportunity to meet with a physician with expertise in the management of CF as well as a family/individual affected by the condition.
Since the time when naturalists were led, by the publication of Charles Darwin's far-famed work on the Origin of Species by Natural Selection, to consider that Man might have been derived through a process of evolution from lower forms of animal life, attention has repeatedly been called to remains, more or less fossilised, which were thought to be transitional forms between the lower animals and Man.
In this paper the author described the results of his observations on the presence of the musculus sternalis in upwards of six hundred bodies dissected in the anatomical rooms of the University of Edinburgh. He had found it in nineteen individuals, i.e., in about 3 per cent of the bodies examined. It occurred nearly equally in the two sexes. It bore no relation to the general muscularity of the individual. In eleven subjects the muscle was single, in eight double, making together twenty-seven specimens of the muscle. The variations which it exhibited in its attachments, size, and shape, were then described. In no case were its fibres continuous with those of the rectus abdominis, or were tendinous intersections found in it, but it mostly arose either from the flattened tendon of the external oblique muscle of the abdomen, or from the cartilages of the lower true ribs, and in many instances it was continuous at its upper end with the sternal tendon of one or both sterno-mastoids, whilst in others it was inserted into the aponeurosis covering the pectoralis major. It was always superficial to the great pectoral muscle. Of the single specimens, four occurred on the right side, two on the left; whilst in the remaining five it arose on one side of the middle line, and was inserted either altogether or in part on the opposite side. It formed an excellent illustration of the truth of the general statement, that occasional and rudimentary structures are especially liable to variations in arrangement.
In August 1901 Mr Thomas Anderson, merchant, Hillswick, to whom and to other members of whose family I have on several occasions been indebted for specimens to illustrate the Zoology of Shetland, wrote to tell me that a dead whale had been found floating near Hillswick and had been towed into Roeness Voe. It was within three miles of land when seen by the fishermen and was claimed by the Crown. From the appearance of the animal Mr Anderson thought that it was a sperm whale, and he sent me the following description, from which it was clear that he had correctly recognised it.