ARCTIC CHANGE AND POSSIBLE INFLUENCE ON MID-LATITUDE CLIMATE AND WEATHER: A US CLIVAR White Paper.

The Arctic has warmed more than twice as fast as the global average since the mid 20th century, a phenomenon known as Arctic amplification (AA). These profound changes to the Arctic system have coincided with a period of ostensibly more frequent events of extreme weather across the Northern Hemisphere (NH) mid-latitudes, including extreme heat and rainfall events and recent severe winters. Though winter temperatures have generally warmed since 1960 over mid-to-high latitudes, the acceleration in the rate of warming at high-latitudes, relative to the rest of the NH, started approximately in 1990. Trends since 1990 show cooling over the NH continents, especially in Northern Eurasia. The possible link between Arctic change and mid-latitude climate and weather has spurred a rush of new observational and modeling studies. A number of workshops held during 2013-2014 have helped frame the problem and have called for continuing and enhancing efforts for improving our understanding of Arctic-mid-latitude linkages and its attribution to the occurrence of extreme climate and weather events. Although these workshops have outlined some of the major challenges and provided broad recommendations, further efforts are needed to synthesize the diversified research results to identify where community consensus and gaps exist. Building upon findings and recommendations of the previous workshops, the US CLIVAR Working Group on Arctic Change and Possible Influence on Mid-latitude Climate and Weather convened an international workshop at Georgetown University in Washington, DC, on February 1-3, 2017. Experts in the fields of atmosphere, ocean, and cryosphere sciences assembled to assess the rapidly evolving state of understanding, identify consensus on knowledge and gaps in research, and develop specific actions to accelerate progress within the research community. With more than 100 participants, the workshop was the largest and most comprehensive gathering of climate scientists to address the topic to date. In this white paper, we synthesize and discuss outcomes from this workshop and activities involving many of the working group members. WORKSHOP FINDINGS: Rapid Arctic change - Emergence of new forcing (external and internal) of atmospheric circulation: Rapid Arctic change is evident in the observations and is simulated and projected by global climate models. AA has been attributed to sea ice and snow decline (regionally and seasonally varying). However this cannot explain why AA is greatest in winter and weakest in summer. It was argued at the workshop that other factors can also greatly contribute to AA including: increased downwelling longwave radiation from greenhouse gases (including greater water vapor concentrations from local and remote sources); increasing ocean heat content, due to local and remote processes; regional and hemispheric atmospheric circulation changes; increased poleward heat transport in the atmosphere and ocean; and cloud radiative forcing. In particular, there is emerging observational evidence that an enhanced poleward transport of sensible and latent heat plays a very important role in the AA of the recent decades, and that this enhancement is mostly fueled by changes in the atmospheric circulation. We concluded that our understanding of AA is incomplete, especially the relative contributions from the different radiative, thermodynamic, and dynamic processes.Arctic mid-latitude linkages - Focusing on seasonal and regional linkages and addressing sources of inconsistency and uncertainty among studies: The topic of Arctic mid-latitude linkages is controversial and was vigorously debated at the workshop. However, we concluded that rapid Arctic change is contributing to changes in mid-latitude climate and weather, as well as the occurrence of extreme events. But how significant the contribution is and what mechanisms are responsible are less well understood. Based on the synthesis efforts of observational and modeling studies, we identified a list of proposed physical processes or mechanisms that may play important roles in linking Arctic change to mid-latitude climate and weather. The list, ordered from high to low confidence, includes: increasing geopotential thickness over the polar cap; weakening of the thermal wind; modulating stratosphere-troposphere coupling; exciting anomalous planetary waves or stationary Rossby wave trains in winter and modulating transient synoptic waves in summer; altering storm tracks and behavior of blockings; and increasing frequency of occurrence of summer wave resonance. The pathway considered most robust is the propagation of planetary/Rossby waves excited by the diminished Barents-Kara sea ice, contributing to a northwestward expansion and intensification of the Siberian high leading to cold Eurasian winters. OPPORTUNITIES AND RECOMMENDATIONS: An important goal of the workshop was achieved: to hasten progress towards consensus understanding and identification of knowledge gaps. Based on the workshop findings, we identify specific opportunities to utilize observations and models, particularly a combination of them, to enable and accelerate progress in determining the mechanisms of rapid Arctic change and its mid-latitude linkages.Observations: Due to the remoteness and harsh environmental conditions of the Arctic, in situ observational time series are highly limited spatially and temporally in the region.Six recommendations to expand approaches using observational datasets and analyses of Arctic change and mid-latitude linkages include: Synthesize new Arctic observations;Create physically-based sea ice-ocean surface forcing datasets;Systematically employ proven and new metrics;Analyze paleoclimate data and new longer observational datasets;Utilize new observational analysis methods that extend beyond correlative relationships; andConsider both established and new theories of atmospheric and oceanic dynamics to interpret and guide observational and modeling studies.Model experiments: We acknowledge that models provide the primary tool for gaining a mechanistic understanding of variability and change in the Arctic and at mid-latitudes. Coordinated modeling studies should include approaches using a hierarchy of models from conceptual, simple component, or coupled models to complex atmospheric climate models or fully coupled Earth system models. We further recommend to force dynamical models with consistent boundary forcings.Three recommendations to advance modeling and synthesis understanding of Arctic change and mid-latitude linkages include: Establish a Modeling Task Force to plan protocols, forcing, and output parameters for coordinated modeling experiments (Polar Amplification Model Intercomparison Project; PAMIP);Furnish experiment datasets to the community through open access (via Earth System Grid); andPromote analysis within the community of the coordinated modeling experiments to understand mechanisms for AA and to further understand pathways for Arctic mid-latitude linkages.

Surgical anatomy of the spinal accessory nerve: review of the literature and case report of a rare anatomical variant.

OBJECTIVE: To evaluate the prevalence of variations in the anatomical route of the spinal accessory nerve from the base of the skull to the point where it enters the trapezius muscle. A case report is used to demonstrate an example of a rare but clinically important anatomical variant of this nerve. METHODS: An independent review of the literature using Medline, PubMed and Q Read databases was performed using combinations of terms including 'spinal accessory nerve', 'anatomy', 'surgical anatomy', 'anatomical variant', 'cranial nerve XI' and 'shoulder syndrome'. RESULTS: Our report demonstrates marked variation in spinal accessory nerve anatomy. At the point of crossing over the internal jugular vein, the spinal accessory nerve passes most commonly laterally (anterior) to the internal jugular vein. The reported incidence of this lateral relationship varies from 67 to 96 per cent. The nerve can also pierce the internal jugular vein, as demonstrated in our case study, with incidence ranging from 0.48 to 3.3 per cent. CONCLUSION: Anatomical variations of the spinal accessory nerve are not uncommon, and it is important for the surgeon to be aware of such variations when undertaking surgery in both the anterior and posterior triangles of the neck.

Lipohypertrophy: does it matter in daily life? A study using a continuous glucose monitoring system.

AIMS: To use continuous glucose monitoring (CGMS) to compare glucose profiles in people with type 1 diabetes following injection of insulin into an area affected by lipohypertrophy vs. an area not affected by lipohypertrophy. METHODS: Eight patients with type 1 diabetes underwent 72 h of CGMS while following a standardized diet and injecting all insulin either into an area with or without lipohypertrophy. Patients underwent two testing periods in random order, separated by 4 days. On day 1 of each test subjects were admitted for measurement of insulin and plasma glucose levels immediately prior to, and hourly for 4 h following, a standardized lunch. RESULTS: Insulin area under the curve (AUC)(0-4 h) was similar for both test periods; 656; interquartile range (IQR): 518-1755 (normal tissue) vs. 602; IQR: 382-1436 (lipohypertrophic tissue), z = 1.7, p = 0.09. There was also no difference in the median time to maximal insulin concentration (Time(max) 2 h; IQR: 2-3 h; z = 0.6; p = 0.6). There was a 37.5% increase in mean plasma glucose levels following a standardized meal; however this was not significant between sites (AUC(0-4 h)t = -1.7; p = 0.1). Moreover, there was no difference in CGMS profiles (AUC(1-72 h)t = -0.9; p = 0.4) across the 72-h monitoring period. Overall the prevalence of hypoglycaemia (CGMS readings < 4 mmol/l) was similar between injection sites (11.6 vs. 10.6%, p = 0.1). CONCLUSION: The pharmacokinetic and pharmacodynamic effect of injecting into lipohypertrophic tissue is small in comparison to the usual clinical variation observed with insulin injections.

Differential shared care for diabetes: does it provide the optimal partition between primary and specialist care?

AIMS: To establish whether a system of differential shared care between general practitioners and specialists is compatible with patients receiving the level of care they require. METHODS: We sought to trace 200 shared care patients whose care had been kept at the general practitioner level after initial referral and compared them with a group of patients who had been re-referred to the Royal Prince Alfred Hospital Diabetes Centre for specialist review. RESULTS: There were no significant differences in glycaemic, blood pressure and lipid levels of returned and non-returned patients at initial assessment. However, non-returned patients were less likely to have a history of macrovascular disease or risk factor (adjusted odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2-0.6). Their referral letter was also more likely to emphasize their type and/or duration of diabetes (adjusted OR 4.6; 95% CI 2.5-8.4). Nearly half (47.1%) of the non-returned group changed their doctor in the years following their initial specialist review, increasing their likelihood of not being re-referred five-fold (adjusted OR 5.0; 95% CI 2.9-8.8). At initial assessment, non-returned patients were given less treatment recommendations (adjusted OR 0.5; 95% CI 0.3-0.7). Doctors registered with the Diabetes Shared Care Programme referred more patients than their non-shared care counterparts. However, a higher proportion of these doctors (52.5% vs. 21.3%; chi(2) = 16.5, 1 d.f., P = 0.00005) were selective in whom they re-referred. CONCLUSION: Differential shared care encourages appropriate referral to specialist services, without compromise to standards of care. Diabet. Med. 18, 554-557 (2001)

Continuity of care in diabetes: to whom does it matter?

The Australian health care system allows patients to move around to seek medical treatment. This may impact negatively on continuity of care. To determine factors associated with continuity of care for persons with diabetes, the profiles of 479 patients attending the Diabetes Centre, Royal Prince Alfred Hospital, Sydney, Australia, were examined. The majority of patients (87.7%) attended only one general practitioner and had been under the care of the referring doctor for a median of 6.2 years. These patients were older (P=0.02), but were comparable with those attending multiple doctors in terms of their type, duration and treatment of diabetes as well as their clinical and complication profile. There was also a relationship between age and the length of time under the care of the referring doctor (P=0.0002). The HbA(1c), lipid, blood pressure and treatment profiles of patients attending the referring doctor short, medium or long-term were comparable. However, there was an upward trend in the proportion of patients with a history of cerebrovascular disease, ischaemic heart disease or any complication of diabetes with each incremental increase in length of time under the referring doctor. Appropriately, patients seek continuity of care as they age and their health needs become more complex.

Use of Medicare services related to diabetes care: the impact of rural isolation.

This study used Medicare data for people living in New South Wales (NSW) (1993-1997) to examine the impact of rural isolation on the utilisation of diabetes health care services. The relative odds of attending a specialist was slightly higher for people in urban areas when compared to their rural counterparts but reached as high as 1.85 in regard to attendance to consultant physicians. Surveillance of diabetes parameters over the 5 year period showed greatest improvement in rural areas. The proportion of patients each year with glycaemic control assessed by quantification of glycosylated haemoglobin (HbA1c) or renal function and vascular risk by microalbuminuria estimation rose to 57.4% and 12.3%, respectively, in rural areas compared to 55.2% and 11.3% in major urban areas. This study has shown that the level of monitoring in rural areas is equal to urban areas, despite decreased access to medical care, highlighting the vital role GPs play in diabetes management in rural NSW.

The pattern of diabetes care in New South Wales: a five-year analysis using Medicare occasions of service data.

OBJECTIVE: To use Medicare occasions of service data to establish the pattern and standard of care received by people with diabetes. METHOD: Information about visits to medical practitioners as well as utilisation of diabetes related procedures for people living in New South Wales (NSW) for the individual years between 1993 to 1997 was retrieved using a Health Insurance Commission data file. Individuals were deemed to have diabetes if an HbA1c which can only be ordered for a person with known diabetes, had been performed over the five-year period. RESULTS: On average over the study period, persons with diabetes accounted for 3.1% of the population but they used 5.5% of general practitioner services. A large proportion of patients also received care at the specialist and consultant physician level, 51.2% and 38.6% respectively, a three to four fold increase when compared with their non-diabetic counterparts. There was also a 1.3 to 1.8 fold increase in the mean number of attendances to the various medical practitioners. Surveillance of diabetes parameters was inadequate but small improvements were seen over the 5 year study period (proportion of persons with diabetes with a HbA1c performed: 48.8% to 56.8%; Lipids: 49.4% to 52.0%; HDL cholesterol: 18.3% to 18.8%; microalbuminuria: 4.7% to 11.6%). CONCLUSION: This study has highlighted the heavy burden imposed by diabetes on our health care system. IMPLICATIONS: The use of Medicare occasions of service data represents a cost efficient way of monitoring health service utilisation.

Diabetes management: shared care or shared neglect.

Shared care is increasingly being advocated as a way of managing patients with diabetes. While this approach has been supported by clinical trials, the success of shared care in 'real life' is not well established. If health care professionals leave undone what they think is done by others, shared care can become neglected care. Follow up of 200 'shared care' patients who had been referred to the Royal Prince Alfred Diabetes Centre, Sydney, Australia on two or more occasions between October 1995 and September 1998 showed that the majority of specialist recommendations regarding metabolic control (76%), referral to an ophthalmologist (73%) and blood pressure treatment (76%) had been implemented by the primary care physician; however, they were less likely to implement recommendations regarding lipid treatment (55%). The median HbA1c (7.6% vs. 8.4%; P = 0.04), cholesterol (5.6 vs. 6.8 mmol/l; P = 0.0005) and triglyceride (2.0 vs. 2.8 mmol/l; P = 0.05) levels for patients in whom recommendations had been implemented were significantly lower at the time of second referral. Doctors registered with the Diabetes Shared Care Programme and those who wrote longer letters were more likely to implement recommendations than their counterparts (87.2%, versus 70.9%; chi2 = 4.12, 1 df; P = 0.04 and 56 words (inter-quartile range (IQR): 36-71) versus 45 words (IQR: 23-59); P = 0.02, respectively). It therefore appears that diabetes care can be well provided by a shared care approach. However, further monitoring of different shared care models is warranted.

Low literacy: a problem in diabetes education.

Eighty-five diabetic patients who were proficient in English were studied to assess the impact of educational material of varying literacy levels on patient comprehension. Two samples of available diabetes foot care material of Grade 11 and 9 readability (measured by SMOG formula) and purposely written in-house material of Grade 6 readability were used. Patients were randomized to read information of either Grade 6 and Grade 11 or Grade 6 and Grade 9 readability. Socio-demographic data and reading habits were collected to allow for identification of literacy markers. The mean CLOZE score (a measure of comprehension) was better in patients who read the Grade 6 information than for both the Grade 11 and Grade 9 information (59.5 +/- 11.8, 46.8 +/- 22.0, 45.8 +/- 22.2 respectively, p < 0.001). When evaluated in terms of percent of patients that could independently understand the material, Grade 6 information outperformed the Grade 11 and Grade 9 information (60%, 19%, 21%, respectively, p < 0.001). For the Grade 11 and Grade 9 information, poorer comprehension was associated with a non-English speaking background, early school leaving age, infrequent reading habits, and preference for tabloids (p < 0.02). Comprehension when patients read the Grade 6 information was no longer dependent on two of the four identified literacy markers. We conclude that reducing literacy demands of health literature improves patients' comprehension. Attention to socio-demographic data and reading habits can assist educators in assessing patients' literacy status and ensuring patients are given literature of compatible readability.

Diabetes education: whose priorities are met?

Two hundred Type 2 diabetic patients newly referred to the diabetes centre at a large university teaching hospital were studied over an 8-month period. Patients completed a diabetes knowledge questionnaire, and specified their educational priorities by selecting six diabetes-related topics from a list of 14. After giving 1 h of individual education and using the same list, the educators selected six topics which they considered to be most important for that particular patient to know. Choice of educational priorities differed between the patients and the corresponding educator (p less than 0.001). In only 38% of cases did the educators' first three priorities coincide with those of the patients. The major discrepancies were in the selection of 'sick day management' and 'complications', especially favoured by patients, as against 'oral hypoglycaemic agents' and other therapy-related topics, especially favoured by educators. Diabetes knowledge was a determinant of educational priority for patients (p less than 0.001) but not educators. In contrast, only the educators' overall choices were affected by duration of diabetes (p less than 0.001). Diabetes treatment type influenced both patients' and educators' selection of priorities (p less than 0.001). We conclude that an educational strategy which relies on health professionals' perceptions to determine what diabetic patients need to know may be inadequate.

The effects of dexfenfluramine on blood glucose control in patients with type 2 diabetes.

Dexfenfluramine has been shown to promote weight loss in overweight people. The present double-blind study was designed to test whether the addition of dexfenfluramine to conventional oral hypoglycaemic treatment would promote weight loss and improve blood glucose control in overweight patients with Type 2 diabetes. The 34 patients studied were randomly assigned to dexfenfluramine or placebo therapy which was added for 12 weeks to their existing treatment regimens of metformin with or without a sulphonylurea. Dexfenfluramine treatment was associated with a significant reduction in weight (98.7 +/- 5.0 (+/- SE) vs 94.9 +/- 5.2 kg; p less than 0.001), BMI (35.0 +/- 1.2 vs 33.6 +/- 1.9 kg m-2; p less than 0.001), HbA1c (7.5 +/- 0.3 vs 6.3 +/- 0.2%; p less than 0.001), fructosamine (313.9 +/- 17.6 vs 274.3 +/- 10.4 mumol l-1; p less than 0.01), systolic (137 +/- 5 vs 128 +/- 6 mmHg; p less than 0.05), and diastolic blood pressure (85 +/- 2 vs 73 +/- 3 mmHg; p less than 0.001). At the end of the study period, the dexfenfluramine treated group had a significantly lower HbA1c (6.3 +/- 0.2 vs 7.2 +/- 0.4; p less than 0.05), fructosamine level (274.3 +/- 10.4 vs 313.3 +/- 16.1 mumol l-1; p less than 0.05) and diastolic blood pressure (73 +/- 3 vs 81 +/- 3 mmHg; p less than 0.03) when compared with the placebo group. In those patients treated with dexfenfluramine, the reduction in HbA1c and blood pressure did not correlate with the decrease in BMI (r = 0.44 and 0.12, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

A real-time automated visual inspection system for hot steel slabs.

This paper describes an inspection system designed to automatically detect and classify surface imperfections occurring on continuously cast hot steel slabs in a steel mill. The need to perform inspection at real-time throughput rates of 546 Kpixels/s using off-the-shelf components has led to the development of a unique architecture and algorithm set. The segmentation operations are done in a high-speed array processor front end. The imperfection classification is done in a mini-computer which uses statistical as well as syntactic/semantic classification techniques. The inspection system is currently undergoing evaluation in a steel mill.

Surface observations for the evaluation of geophysical measurements from seasat.

The surface observations used in the initial assessment of Seasat are discussed with emphasis on their ability to describe the synoptic-scale winds over the ocean.

Seasat scatterometer: results of the gulf of alaska workshop.

The Seasat microwave scatterometer was designed to measure, globally and in nearly all weather, wind speed to an accuracy of +/- 2 meters per second and wind direction to +/- 20 degrees in two swaths 500 kilometers wide on either side of the spacecraft. For two operating modes in rain-free conditions, a limited number of comparisons to high-quality surface truth indicates that these specifications may have been met.