Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.

Production, use, and fate of all plastics ever made

A Treatise on the Family. G. S. Becker. Cambridge, MA: Harvard University Press. 1981. Gary Becker is one of the most famous and influential economists of the second half of the 20th century, a fervent contributor to and expounder of the University of Chicago free-market philosophy, and winner of the 1992 Nobel Prize in economics. Although any book with the word "treatise" in its title is clearly intended to have an impact, one coming from someone as brilliant and controversial as Becker certainly had such a lofty goal. It has received many article-length reviews in several disciplines (Ben-Porath, 1982; Bergmann, 1995; Foster, 1993; Hannan, 1982), which is one measure of its scholarly importance, and yet its impact is, I think, less than it may have initially appeared, especially for scholars with substantive interests in the family. This book is, its title notwithstanding, more about economics and the economic approach to behavior than about the family. In the first sentence of the preface, Becker writes "In this book, I develop an economic or rational choice approach to the family." Lest anyone accuse him of focusing on traditional (i.e., material) economics topics, such as family income, poverty, and labor supply, he immediately emphasizes that those topics are not his focus. "My intent is more ambitious: to analyze marriage, births, divorce, division of labor in households, prestige, and other non-material behavior with the tools and framework developed for material behavior." Indeed, the book includes chapters on many of these issues. One chapter examines the principles of the efficient division of labor in households, three analyze marriage and divorce, three analyze various child-related issues (fertility and intergenerational mobility), and others focus on broader family issues, such as intrafamily resource allocation. His analysis is not, he believes, constrained by time or place. His intention is "to present a comprehensive analysis that is applicable, at least in part, to families in the past as well as the present, in primitive as well as modern societies, and in Eastern as well as Western cultures." His tone is profoundly conservative and utterly skeptical of any constructive role for government programs. There is a clear sense of how much better things were in the old days of a genderbased division of labor and low market-work rates for married women. Indeed, Becker is ready and able to show in Chapter 2 that such a state of affairs was efficient and induced not by market or societal discrimination (although he allows that it might exist) but by small underlying household productivity differences that arise primarily from what he refers to as "complementarities" between caring for young children while carrying another to term. Most family scholars would probably find that an unconvincingly simple explanation for a profound and complex phenomenon. What, then, is the salient contribution of Treatise on the Family? It is not literally the idea that economics could be applied to the nonmarket sector and to family life because Becker had already established that with considerable success and influence. At its core, microeconomics is simple, characterized by a belief in the importance of prices and markets, the role of self-interested or rational behavior, and, somewhat less centrally, the stability of preferences. It was Becker's singular and invaluable contribution to appreciate that the behaviors potentially amenable to the economic approach were not limited to phenomenon with explicit monetary prices and formal markets. Indeed, during the late 1950s and throughout the 1960s, he did undeniably important and pioneering work extending the domain of economics to such topics as labor market discrimination, fertility, crime, human capital, household production, and the allocation of time. Nor is Becker's contribution the detailed analyses themselves. Many of them are, frankly, odd, idiosyncratic, and off-putting. …

A Treatise on the Family

In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

Forecasting, Structural Time Series Models and the Kalman Filter

Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

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Climate Change 2007: Impacts, Adaptation and Vulnerability.

In 1997, the global value of ecosystem services was estimated to average $33 trillion/yr in 1995 $US ($46 trillion/yr in 2007 $US). In this paper, we provide an updated estimate based on updated unit ecosystem service values and land use change estimates between 1997 and 2011. We also address some of the critiques of the 1997 paper. Using the same methods as in the 1997 paper but with updated data, the estimate for the total global ecosystem services in 2011 is $125 trillion/yr (assuming updated unit values and changes to biome areas) and $145 trillion/yr (assuming only unit values changed), both in 2007 $US. From this we estimated the loss of eco-services from 1997 to 2011 due to land use change at $4.3–20.2 trillion/yr, depending on which unit values are used. Global estimates expressed in monetary accounting units, such as this, are useful to highlight the magnitude of eco-services, but have no specific decision-making context. However, the underlying data and models can be applied at multiple scales to assess changes resulting from various scenarios and policies. We emphasize that valuation of eco-services (in whatever units) is not the same as commodification or privatization. Many eco-services are best considered public goods or common pool resources, so conventional markets are often not the best institutional frameworks to manage them. However, these services must be (and are being) valued, and we need new, common asset institutions to better take these values into account.

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Changes in the global value of ecosystem services

Background/aim To assess the long-term safety and efficacy of epimacular brachytherapy (EMB) for chronic, active, neovascular age-related macular degeneration (nAMD). Methods This pivotal, randomised, controlled surgical device trial recruited patients with chronic nAMD receiving intravitreal ranibizumab from 24 UK hospitals. Participants were randomised to either pars plana vitrectomy with 24 Gray EMB and pro re nata (PRN) ranibizumab (n=224) or PRN ranibizumab monotherapy (n=119). Although masking was not possible, masked clinicians assessed best-corrected visual acuity (BCVA) and imaging. After month 24, participants reverted to standard care, with either ranibizumab or aflibercept, returning for a month 36 study visit. Results Of 363 participants, 309 (85.1%) completed month 36. The number of injections was 12.1±8.1 in the EMB group versus 11.4±6.1 in the ranibizumab group (difference 0.7, 95% CI of difference −0.9 to 2.3, p=0.41) between months 1 and 36, and 3.6±3.3 (n=200) versus 3.9±2.7 (n=102) (difference −0.3, 95% CI of difference −1.0 to 0.4, p=0.43) between months 25 and 36 (standard care). Over 36 months, BCVA change was −19.7±18.5 letters in the EMB group and −4.8±12.5 in the ranibizumab group (difference −14.9, 95% CI of difference −18.5 to −11.2, p<0.0001). The month 36 BCVA of 20 EMB-treated participants with microvascular abnormalities (MVAs) at month 24 was similar to EMB-treated participants without MVAs (−21.8 vs −19.4 letters, p=0.65). Conclusion EMB does not reduce the number of anti-vascular endothelial growth factor (VEGF) injections, either within or outside of a trial setting, and is associated with worse BCVA than anti-VEGF monotherapy. Trial registration number NCT01006538.

Epimacular brachytherapy for previously treated neovascular age-related macular degeneration: month 36 results of the MERLOT randomised controlled trial

Relationship between dietary intake components and hepatic fibrosis in those with obesity before and 1 year after bariatric surgery.

Background: Marked associations between obesity and the development of knee symptoms have been well established. The prevalence of obesity in Western populations has continued to rise over the past decades, and this has been associated with a significant rise in the number of patients with debilitating knee symptoms who are obese. While these patients may be referred to orthopaedic surgeons for assessment and consideration of treatment options, they may lack intra-articular pathology amenable to orthopaedic surgical intervention such as a Total Knee Arthroplasty (TKA). Laparoscopic roux-en-y gastric bypass (LRYGB) surgery is one of the more effective ways to induce and maintain weight loss, and while bariatric surgery has been reported to provide significant reductions in knee symptoms no studies have compared the magnitude of change is symptoms compared to TKA. The purpose of this study was to assess the impact of LRYGB on knee-specific patient reported outcomes, and to compare these findings to a matched cohort of patients who underwent TKA for OA.
Methods and findings: Twenty patients who underwent bariatric surgery were matched on a one-to-two basis to forty patients who had previously undergone unilateral primary TKA at a single institution. WOMAC scores were collected at baseline and at 6 and 12 month follow ups. The mean percentage improvement in knee-specific pain scores was similar between groups at both 6 month (49.9% vs. 58.3%; p=0.438) and 1 year (62.7% vs. 68.2%; p=0.576) follow-up intervals. Furthermore, patients who underwent LRYGB had significantly greater mean percent improvement in knee-specific WOMAC function scores at 6 month followup (66.3% vs. 46.8%; p=0.048), and a similar though marginally non-significant improvement at 12 month followup (68.4% vs. 51.6%; p=0.094).
Conclusion: The relative improvement in symptoms of a group of LRYBG patients was similar to that of a matched group of patients who underwent TKA for end-stage OA. While further work is needed to better delineate the contribution of elevated BMI to knee symptoms, as well as to ascertain whether these findings are maintained at longer-term follow-up, surgeons should consider bariatric consultation for obese patients with knee symptoms lacking either focal pathology amenable to orthopaedic management or degenerative changes sufficiently advanced to warrant joint arthroplasty.

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The Impact of Gastric Bypass Surgery Compared to Total Knee Arthroplasty on Knee Symptoms

The reported incidence of surgical site infection (SSI) following bariatric surgery ranges from 1.4 to 30%. The use of skin staples and tissue adhesive was shown to be superior to sutures in reducing SSI in a variety of surgical disciplines; however, this area is under-investigated in elective bariatric surgery. The aim of this study was to examine the effect of tissue adhesive for skin closure on SSI in patients undergoing bariatric surgery. A retrospective analysis was performed to determine the incidence of SSI in patients who underwent elective laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). Tissue adhesive was selectively used for skin closure during the study period. Patient characteristics, operative data, and 30-day postoperative outcomes were collected from patient charts and the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database. A total of 1,579 patients were included in the study. Tissue adhesive was used in 31.2% of all operations (n = 494). The rate of incisional SSI in our study was 2.2% (n = 35). The use of tissue adhesive was more common in patients who developed incisional SSI compared with those without incisional SSI (54.3 vs. 30.8%, p = 0.003). On multivariate analysis, the use of tissue adhesive remained an independent predictor for the development of incisional SSI (OR 2.77, p = 0.007). The use of tissue adhesive was an independent predictor for incisional SSI following elective bariatric surgery. This is the first study to report the effects of tissue adhesive in this patient population.

The Effect of Tissue Adhesive on Surgical Site Infection Following Elective Bariatric Surgery: a Retrospective Cohort Study

Reliability of Non-invasive Liver Fibrosis Assessment Tools Versus Biopsy in Pre- and Post-bariatric Surgery Patients with Non-alcoholic Fatty Liver Disease

Tim Jackson

Papers

Epimacular brachytherapy for previously treated neovascular age-related macular degeneration: month 36 results of the MERLOT randomised controlled trial

Relationship between dietary intake components and hepatic fibrosis in those with obesity before and 1 year after bariatric surgery.

The Impact of Gastric Bypass Surgery Compared to Total Knee Arthroplasty on Knee Symptoms

The Effect of Tissue Adhesive on Surgical Site Infection Following Elective Bariatric Surgery: a Retrospective Cohort Study

Reliability of Non-invasive Liver Fibrosis Assessment Tools Versus Biopsy in Pre- and Post-bariatric Surgery Patients with Non-alcoholic Fatty Liver Disease