Observations, inferences, and mechanisms of the Atlantic Meridional Overturning Circulation: A review

This is a review about the Atlantic Meridional Overturning Circulation (AMOC), its mean structure, temporal variability, controlling mechanisms, and role in the coupled climate system. The AMOC plays a central role in climate through its heat and freshwater transports. Northward ocean heat transport achieved by the AMOC is responsible for the relative warmth of the Northern Hemisphere compared to the Southern Hemisphere and is thought to play a role in setting the mean position of the Intertropical Convergence Zone north of the equator. The AMOC is a key means by which heat anomalies are sequestered into the ocean's interior and thus modulates the trajectory of climate change. Fluctuations in the AMOC have been linked to low-frequency variability of Atlantic sea surface temperatures with a host of implications for climate variability over surrounding landmasses. On intra-annual timescales, variability in AMOC is large and primarily reflects the response to local wind forcing; meridional coherence of anomalies is limited to that of the wind field. On interannual to decadal timescales, AMOC changes are primarily geostrophic and related to buoyancy anomalies on the western boundary. A pacemaker region for decadal AMOC changes is located in a western “transition zone” along the boundary between the subtropical and subpolar gyres. Decadal AMOC anomalies are communicated meridionally from this region. AMOC observations, as well as the expanded ocean observational network provided by the Argo array and satellite altimetry, are inspiring efforts to develop decadal predictability systems using coupled atmosphere-ocean models initialized by ocean data.United States. National Oceanic and Atmospheric Administration (NA10OAR4310199)Unites States. National Oceanic and Atmospheric Administration (NA13OAR4310134)United States. National Oceanic and Atmospheric Administration (NA150AR4310100)United States. National Oceanic and Atmospheric Administration (NA09OAR4310058)United States. National Oceanic and Atmospheric Administration (NA14OAR4310160)National Science Foundation (U.S.) (1338427)United States. National Aeronautics and Space Administration (NNX14AM19G

Experience can increase prism fusion range

Aim: Differences in near prism fusion ranges (PFR) were assessed in 4 groups of participants who differed in experience of exposure to such testing. The effect of encouragement in the two least experienced groups was also tested. Methods: The near base in (BI) and base out (BO) fusional amplitudes (FA) were measured in four groups of 10 participants, all with normal or corrected to normal vision. One group was naÏve to such testing, being non-orthoptic students, the other three groups consisted separately of Year One, Two and Three student orthoptists. The two most inexperienced groups, NaÏve and Year One student orthoptists, were also tested a second time with encouragement to try as hard as possible to increase their fusion amplitudes. Results: Year Two and Year Three students had significantly ( p < 0.001, often over 20∆) larger BO FA than naÏve students or Year One orthoptic students. No such differences were seen for BI measures. Encouragement also significantly ( p < 0.01), but modestly (<6∆), increased BO FA and slightly (about 1∆, p < 0.05) increased BI FA. Conclusions: Experience did increase PFR but this was mainly in BO fusion amplitudes and was far greater than obtained by encouraging participants. The experience needed to obtain this increase appeared to be the exposure occurring in one year of training to be an orthoptist. Further experiments could help clarify the factors involved in this improvement by tracking any increase throughout this first year and also look for changes in performance in other orthoptic tests

Five year prognosis in patients with angina identified in primary care : incident cohort study

Peer reviewedPublisher PD

Vertebrate Natural History Notes from Arkansas, 2017

Because meaningful observations of natural history are not always part of larger studies, important pieces of information often are unreported. Small details, however, can fills gaps in understanding and also lead to interesting questions about ecological relationships or environmental change. We have compiled recent observations of foods, reproduction, record size, parasites, and distribution of 30 species of fishes, new records of distribution and parasites of 2 species of amphibians, and new records of distribution, parasites, reproduction and anomalies of 11 species of mammals

Invasive neuroendocrine tumor of the kidney: a case report

Neuroendocrine tumors (NETs) involve the genitourinary system in less than 1% of cases, with primary renal carcinoids comprising only 19% of reported genitourinary NETs (56 cases worldwide). We report a case of a renal NET presenting as a large renal mass with extensive local invasion, requiring definitive radical en bloc resection via a thoracoabdominal approach

Judgements of Solomon: anxieties and defences of social workers involved in care proceedings

Evidence from focus group discussions with social workers in child care and child protection was collected for a research project exploring decision-making in care proceedings and seeking a better understanding of the causes of delay in the process. Here this material is used to examine social workers’ feelings about their work and to explore the anxieties they expressed. Isabel Menzies’s work on containing anxiety in institutions is used to provide a conceptual framework for thinking about the ways in which individuals’ unconscious defences against anxiety may affect the structure, policies and practices of the organization in which they work. It is suggested that this dimension needs to be taken into account in understanding difficulties which arise in putting policy into practice

Evaluating implicit feedback models using searcher simulations

In this article we describe an evaluation of relevance feedback (RF) algorithms using searcher simulations. Since these algorithms select additional terms for query modification based on inferences made from searcher interaction, not on relevance information searchers explicitly provide (as in traditional RF), we refer to them as implicit feedback models. We introduce six different models that base their decisions on the interactions of searchers and use different approaches to rank query modification terms. The aim of this article is to determine which of these models should be used to assist searchers in the systems we develop. To evaluate these models we used searcher simulations that afforded us more control over the experimental conditions than experiments with human subjects and allowed complex interaction to be modeled without the need for costly human experimentation. The simulation-based evaluation methodology measures how well the models learn the distribution of terms across relevant documents (i.e., learn what information is relevant) and how well they improve search effectiveness (i.e., create effective search queries). Our findings show that an implicit feedback model based on Jeffrey's rule of conditioning outperformed other models under investigation

Biofilm assists recognition of avian trackways in Late Pleistocene coastal aeolianites, South Africa

Fourteen fossil avian tracksites have been identified in Late Pleistocene aeolianite deposits on the Cape south coast of SouthAfrica. One of these sites is unusual because of the preferential adherence of organic material (biofilm) to the natural cast tracks. This has enabled the recognition and identification of two ~6 m long, approximately parallel trackways that would otherwise not have been noticed. The trackways are visible from a distance of over 100 metres and contain 20 and 14 individual tracks, respectively. Up to 50 avian tracks are evident at this site. As the biofilm layer continues to thicken, the trackways become increasingly visible. Avian trackways of this length are globally rare.We propose that the biofilm adheres to sections with higher relief on a sedimentary surface, and that an understanding of this mode of preservation can be useful to more easily identify trackways in areas of comparable geological setting.JN

Step-induced unusual magnetic properties of ultrathin Co/Cu films: ab initio study

We have performed ab initio studies to elucidate the unusual magnetic behavior recently observed in epitaxial Co films upon absorption of submonolayers of Cu and other materials. We find that a submonolayer amount of Cu on a stepped Co/Cu (100) film changes dramatically the electronic and magnetic structure of the system. The effect is mainly due to hybridization of Co and Cu $d$-electrons when copper forms a ``wire'' next to a Co step at the surface. As a result, a non-collinear arrangement of magnetic moments (switching of the easy axis) is promoted. [PACS 75.70.Ak,75.70.-i]Comment: 10 pages, RevTeX 3.0, 4 PostScript figures available on request from A. Bratkovsky at [email protected]