RESUMO
A sustainable livestock economy depends on both production and consumption, inextricably linked in local, national and global markets. At each scale, technical innovation and production practices need to respond to evolving demand for both market and non-market attributes of livestock systems. This review considers recent and evolving demand-side challenges focussing on emerging preferences related to environmental, dietary and health impacts, arising from both production and consumption. It suggests that these attributes need to be integral to any definition of high-producing animal systems. This discussion is mostly framed using neoclassical economic theory, which highlights market failure and the role of negative and positive external effects or social costs. It examines how our understanding of the demand for these attributes is evolving, leading to market segmentation in some cases, and an existential threat to livestock production as consumption decisions change, investors seek to avoid potential liabilities related to greenhouse gas emissions and potentially antimicrobial resistance, and governments intervene to control other undesirable social costs. The discussion distinguishes between market imperatives in high- and lower-income countries, and how income and consumption trajectories may be less deterministic in a more hyperlinked world where product information may accelerate the evolution of preferences towards and away from livestock products. The review acknowledges the limits of a neoclassical approach, drawing attention to more fundamental concepts of biophysical limits to growth and value pluralism, which indicates values (e.g. intrinsic) that lie beyond the neoclassical framing of demand and value.
Assuntos
Gases de Efeito Estufa , Gado , Animais , DietaRESUMO
PURPOSE: Increasingly, radiologic imaging is obtained as part of the pathway in diagnosing ventral hernias. Often, radiologists receive incomplete or incorrect clinical information from clinicians. OBJECTIVE: The aim of the study is to determine if clinical exam findings alter radiological interpretation of ventral hernias on CT. METHODS: This is a single-institution double-blind, randomized trial. All patients with a recent abdominal/pelvic CT scan seen in various surgical clinics were enrolled. A surgeon blinded to the CT scan findings performed a standardized physical examination and assessed for the presence of a ventral hernia. Seven independent radiologists blinded to the study design reviewed the scans. Each radiologist received one of three types of clinical exam data per CT: accurate (correct), inaccurate (purposely incorrect), or none. Allocation was random and stratified by the presence of clinical hernia. The primary outcome was the proportion of radiologic hernias detected, analyzed by chi square. RESULTS: 115 patients were enrolled for a total of 805 CT scan reads. The proportion of hernias detected differed by up to 25% depending on if accurate, no, or inaccurate clinical information was provided. Inaccurate clinical data in patients with no hernia on physical exam led to a significant difference in the radiologic hernia detection rate (54.3% versus 35.7%, p = 0.007). No clinical data in patients with a hernia on physical exam led to a lower radiologic hernia detection rate (75.0% versus 93.8%, p = 0.001). CONCLUSIONS: The presence and accuracy of clinical information provided to radiologists impacts the diagnosis of abdominal wall hernias in up to 25% of cases. Standardization of both clinical and radiologic examinations for hernias and their reporting are needed. TRIAL REGISTRATION: Clinicaltrials.gov, Number NCT03121131, https://clinicaltrials.gov/ct2/show/NCT03121131.
