Managing the Black Sea Anchovy Fishery with Nutrient Enrichment and a Biological Invader

Many marine systems are subject to high nutrient loadings together with invasions by exotic species. Devising appropriate management responses is an increasing concern and one that has received relatively little attention from researchers. This paper considers the Black Sea anchovy fishery, which has benefited from the relaxation of a nutrient constraint, but has suffered from competition and predation by an invading comb-jelly (Mnemiopsis leidyi). We examine alternative hypotheses about the mechanism triggering outbreaks of the invader (sea temperatures versus nutrients), and the severity of these outbreaks, to see whether a constant escapement policy might be optimal for this fishery. If nutrient levels serve as the triggering mechanism, we argue a mixed blessing effect may be present, so that the effects of nutrient abatement for the anchovy fishery are uncertain. We specify our model empirically and show that a constant escapement policy would be viable under a scenario of reduced impacts from outbreaks of the invader and that nutrient abatement could be beneficial if nutrients trigger outbreaks.Mnemiopsis leidyi, nutrient abatement, stochastic bioeconomic model, biological invasion, Resource /Energy Economics and Policy, O3, O41, Q2, Q20, Q22,

Implications of localism in educational policy on the aspirations of young people in Cornwall

The physical location of Cornwall, England impacts upon its social and economic development and is evident in the aspirations ascribed to and held by young people within the region. Schools have been set the task of raising aspirations, as low expectations are perceived to be a barrier to high attainment in schooling. We draw upon research in two Cornish secondary schools that attempted to raise aspirations through school change and by entering into the Academy schools programme. What we found was that their location was generally perceived as a disadvantage to aspiration. We suggest that within the current climate of localisation in educational policy it will be difficult for individual schools to scrutinise themselves and their practices. It will be difficult to ensure that they do not perpetuate poor social outcomes through entrenched beliefs about a link between physical isolation and social disadvantage

The economics of a "mixed blessing" effect: A case study of the Black Sea

Nutrient enrichment of marine ecosystems is regarded as a pressing global environmental problem. For certain marine species it may be a mixed blessing, resulting in damaging ecosystem events, but contributing to primary productivity. Consequently, the impact of enrichment on fishery profits may be positive or negative. This paper develops a method for analyzing such problems, using the example of the Black Sea anchovy fishery. Employing a bioeconomic model that incorporates nutrients directly into fish population dynamics, the problem is formulated in deterministic and stochastic terms. The deterministic model assumes a given ecological state in which nutrients contribute positively to pelagic fish production. The stochastic model recognizes that the planner may take into account the probability of potentially damaging shifts in ecological states due to nutrient enrichment. In this latter model, nutrient abatement has an indeterminate welfare effect, but under certain conditions a marginal change in nutrients generates positive aggregate benefits

The effects of pollution on open access fisheries: A case study of the Black Sea

There is now increasing recognition that the world's marine ecosystems, especially coastal areas and semi-enclosed seas, are suffering from degradation and modification due to human influences. One of the most serious problems is nutrient enrichment, which in the long term harms productivity and damages the ecosystem. Concurrent with this degradation is a rising awareness of the role of overfishing in the demise of global marine fish stocks, especially where property rights are poorly defined and open access prevails in the fishery. In some regions, such as the Black Sea, the two actions together have led to collapses in fish stocks. However, there has been little investigation of the linkage between the two problems to date. In this paper, we assess the non-efficiency benefits of improving environmental quality in the presence of such linkages, recognising that efficiency benefits may not be significant under the circumstances describing many open access fisheries. We use a dynamic bioeconomic modelling approach which incorporates habitat quality explicitly, first theoretically analysing the comparative static effects of an exogenous reduction in nutrient inputs and then empirically demonstrating the approach using a case study of Black Sea anchovy. The methodology, which may have a wider application to fisheries-pollution problems, allows us to show that pollution abatement significantly raises harvest, employment and revenues at the long run equilibrium of the system. Ultimately, for substantial efficiency benefits to arise from addressing the nutrient enrichment problem requires that the open access problem be addressed as well

Metformin for non-diabetic patients with coronary heart disease (the CAMERA study): a randomised controlled trial

<br>Background: Metformin reduces cardiovascular risk in patients with type 2 diabetes seemingly independent of lowering blood glucose concentration. We assessed the cardiovascular effects of metformin in individuals without type 2 diabetes.</br> <br>Methods: We did a single-centre, double-blind, placebo-controlled trial at the Glasgow Clinical Research Facility (Glasgow, UK). We enrolled patients taking statins who did not have type 2 diabetes but who did have coronary heart disease and large waist circumferences. Participants were randomly assigned (1:1) by computer to either metformin (850 mg twice daily) or matching placebo in block sizes of four. Patients, investigators, trial staff, and statisticians were masked to treatment allocation. The primary endpoint was progression of mean distal carotid intima-media thickness (cIMT) over 18 months in the modified intention-to-treat population. Secondary endpoints were changes in carotid plaque score (in six regions), measures of glycaemia (HbA1c, fasting glucose, and insulin concentrations, and Homeostasis Model Assessment of Insulin Resistance [HOMA-IR]), and concentrations of lipids, high sensitivity C-reactive protein, and tissue plasminogen activator. The trial was registered at ClinicalTrials.gov, number NCT00723307.</br> <br>Findings: We screened 356 patients, of whom we enrolled 173 (86 in the metformin group, 87 in the placebo group). Average age was 63 years. At baseline, mean cIMT was 0·717 mm (SD 0·129) and mean carotid plaque score was 2·43 (SD 1·55). cIMT progression did not differ significantly between groups (slope difference 0·007 mm per year, 95% CI −0·006 to 0·020; p=0·29). Change of carotid plaque score did not differ significantly between groups (0·01 per year, 95% CI −0·23 to 0·26; p=0·92). Patients taking metformin had lower HbA1c, insulin, HOMA-IR, and tissue plasminogen activator compared with those taking placebo, but there were no significant differences for total cholesterol, HDL-cholesterol, non-HDL-cholesterol, triglycerides, high sensitivity C-reactive protein, or fasting glucose. 138 adverse events occurred in 64 patients in the metformin group versus 120 in 60 patients in the placebo group. Diarrhoea and nausea or vomiting were more common in the metformin group than in the placebo group (28 vs 5).</br> <br>Interpretation: Metformin had no effect on cIMT and little or no effect on several surrogate markers of cardiovascular disease in non-diabetic patients with high cardiovascular risk, taking statins. Further evidence is needed before metformin can be recommended for cardiovascular benefit in this population.</br&gt

Long-term weight maintenance and cardiovascular risk factors are not different following weight loss on carbohydrate-restricted diets high in either monounsaturated fat or protein in obese hyperinsulinaemic men and women

The aim of this study was to determine after 52 weeks whether advice to follow a lower carbohydrate diet, either high in monounsaturated fat or low fat, high in protein had differential effects in a free-living community setting. Following weight loss on either a high monounsaturated fat, standard protein (HMF; 50 % fat, 20 % protein (67 g/d), 30 % carbohydrate) or a high protein, moderate fat (HP) (40 % protein (136 g/d), 30 % fat, 30 % carbohydrate) energy-restricted diet (6000 kJ/d) subjects were asked to maintain the same dietary pattern without intensive dietary counselling for the following 36 weeks. Overall weight loss was 6·2 (sd 7·3) kg (P < 0·01 for time with no diet effect, 7·6 (sd 8·1) kg, HMF v. 4·8 (sd 6·6) kg, HP). In a multivariate regression model predictors of weight loss at the end of the study were sex, age and reported percentage energy from protein (R2 0·22, P < 0·05 for the whole model). Fasting plasma insulin decreased (P < 0·01, with no difference between diets), 13·9 (sd 4·6) to 10·2 (sd 5·2) mIU/l, but fasting plasma glucose was not reduced. Neither total cholesterol nor LDL-cholesterol were different but HDL was higher, 1·19 (sd 0·26) v. 1·04 (sd 0·29) (P < 0·001 for time, no diet effect), while TAG was lower, 1·87 (sd 1·23) v. 2·22 (sd 1·15) mmol/l (P < 0·05 for time, no diet effect). C-reactive protein decreased (3·97 (sd 2·84) to 2·43 (sd 2·29) mg/l, P < 0·01). Food records showed that compliance to the prescribed dietary patterns was poor. After 1 year there remained a clinically significant weight loss and improvement in cardiovascular risk factors with no adverse effects of a high monounsaturated fat diet.Jennifer B. Keogh, Natalie D. Luscombe-Marsh, Manny Noakes, Gary A. Wittert and Peter M. Clifto

Understanding experiences of participating in a weight loss lifestyle intervention trial: a qualitative evaluation of South Asians at high risk of diabetes

&lt;b&gt;Objective&lt;/b&gt; To explore the reasons for enrolling, experiences of participating and reasons for remaining in a family-based, cluster randomised controlled trial of a dietitian-delivered lifestyle modification intervention aiming to reduce obesity in South Asians at high risk of developing diabetes.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Design&lt;/b&gt; Qualitative study using narrative interviews of a purposive sample of trial participants following completion of the intervention. Data were thematically analysed.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Setting&lt;/b&gt; The intervention was conducted in Scotland and resulted in a modest decrease in weight, but did not statistically reduce the incidence of diabetes.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Participants&lt;/b&gt; We conducted 21 narrative interviews with 24 participants (20 trial participants and four family volunteers).&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; Many participants were motivated to participate because of: known family history of diabetes and the desire to better understand diabetes-related risks to their own and their family's health; ways to mitigate these risks and to benefit from personalised monitoring. Home-based interventions, communication in the participant's chosen language(s) and continuity in dietitians supported their continuing engagement with the trial. Adaptations in food choices were initially accommodated by participants, although social and faith-based responsibilities were reported as important barriers to persevering with agreed dietary goals. Many participants reported that increasing their level of physical activity was difficult given their long working hours, physically demanding employment and domestic commitments; this being compounded by Scotland's challenging climate and a related reluctance to exercise in the outdoors.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Although participants had strong personal interests in participation and found the information provided by dietitians useful, they nonetheless struggled to incorporate the dietary and exercise recommendations into their daily lives. In particular, increasing levels of physical exercise was described as an additional and in some cases unachievable burden. Consideration needs to be given to strengthening and supporting lifestyle interventions with community-based approaches in order to help overcome wider social and environmental factors

Children's understandings of obesity, a thematic analysis

Childhood obesity is a major concern in today’s society. Research suggests the inclusion of the views and understandings of a target group facilitates strategies that have better efficacy. The objective of this study was to explore the concepts and themes that make up children’s understandings of the causes and consequences of obesity. Participants were selected from Reception (4-5 years old) and Year 6 (10-11 years old), and attended a school in an area of Sunderland, in North East England. Participants were separated according to age and gender, resulting in four focus groups, run across two sessions. A thematic analysis (Braun & Clarke, 2006) identified overarching themes evident across all groups, suggesting the key concepts that contribute to children’s understandings of obesity are ‘‘Knowledge through Education,’’ ‘‘Role Models,’’ ‘‘Fat is Bad,’’ and ‘‘Mixed Messages.’’ The implications of these findings and considerations of the methodology are discussed in full

Computer simulation of syringomyelia in dogs

Syringomyelia is a pathological condition in which fluid-filled cavities (syringes) form and expand in the spinal cord. Syringomyelia is often linked with obstruction of the craniocervical junction and a Chiari malformation, which is similar in both humans and animals. Some brachycephalic toy breed dogs such as Cavalier King Charles Spaniels (CKCS) are particularly predisposed. The exact mechanism of the formation of syringomyelia is undetermined and consequently with the lack of clinical explanation, engineers and mathematicians have resorted to computer models to identify possible physical mechanisms that can lead to syringes. We developed a computer model of the spinal cavity of a CKCS suffering from a large syrinx. The model was excited at the cranial end to simulate the movement of the cerebrospinal fluid (CSF) and the spinal cord due to the shift of blood volume in the cranium related to the cardiac cycle. To simulate the normal condition, the movement was prescribed to the CSF. To simulate the pathological condition, the movement of CSF was blocked

Evaluating Active U: an Internet-mediated physical activity program.

Background: Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U) was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition. Methods: This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load. Results: Overall, 7,483 individuals registered with the Active U website (≈16% of eligible), and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI < 25 were more likely to meet their weekly physical activity goals, and average rate of meeting goals was higher among participants who joined a competitive team compared to those who participated individually (IRR = 1.28, P < .001). Conclusion: Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months