This book examines the legal, ethical and regulatory debates surrounding the rise of the cosmetic procedures industry. In the past, cosmetic procedures were often seen as limited to a small number of wealthy older women. Today, such procedures have gone mainstream, partly facilitated by the rise of 'non-invasive' techniques, such as the use of Botox and Dermal Fillers. While still a business dominated by the female consumer, there is also an increasing number of males undertaking cosmetic procedures as social expectations around appearance and ageing are challenged. At the same time, the rapid expansion of this business and the incoherent, diverse approach to its regulation have given rise to concern. It has been seen as a 'Wild West'. If cosmetic procedures go wrong, such procedures give rise to real risks of harm. This book examines the historical backdrop, current practice and risks associated with cosmetic procedures. It discusses the ethical and regulatory challenges for this area. It also examines the current legal frameworks concerning people, practitioners and products in the UK. The book also draws lessons from regulatory approaches in other jurisdictions with particular reference to the United States, Brazil and France. It then sets out a legal and regulatory framework that might better protect and empower the cosmetic consumer, now and in the future. The book is likely to be of particular interest to those working in the areas of health and medical law, socio-legal studies and political science.

In Righting Health Policy: Bioethics, Political Philosophy, and the Normative Justification of Health Law and Policy, D. Robert MacDougall argues that bioethics does not have adequate tools for justifying its normative recommendations for law and policy. Bioethics' tools are mostly theories about what we owe each other. But justifying laws and policies requires more; at a minimum, it requires explaining the basis on which we may control or influence others to do what they are supposed to do, which lies within the realm of political and not moral philosophy. MacDougall develops an interpretation of Kant's moral and political philosophy and uses this account to show the importance of political philosophy for bioethics. He argues that a theory of political legitimacy is necessary for distinguishing between what is morally required and what is legally enforceable. MacDougall also argues that in some cases, an account of political authority is necessary for settling the content of not only our legal rights and duties but also our moral ones. The Kantian account shows why the content of physicians' duties-legal and moral-to inform patients prior to treatment remain indeterminate outside of a state with authority to conclusively settle what counts as valid consent.

Opening with a detailed account of the historical development of Irish pharmacy and medicines law, this practical textbook covers all aspects of current pharmacy and medicines law in Ireland, including the landmark Pharmacy Act of 2007. The following topics are also covered: the regulations and rules that accompany the Pharmacy Act 2007; prescription and control of supply of medicines; Misuse of Drugs Acts and Regulations; manufacturing and wholesaling medicines; advertising of medicinal products; veterinary medicines legislation; Poisons Act and Regulations; the pharmacy disciplinary system; liability of pharmacists in negligence and defective products; and sources of Irish law. This useful resource is essential reading for Irish pharmacists in community and hospital pharmacy and the pharmaceutical industry in Ireland, pharmacy students and those coming to practise in Ireland from other countries. It will also be a valuable reference source for lawyers, public servants and anyone else who wants to know more about the regulatory framework for pharmacists and medicinal products in Ireland.

Whether you are a doctor, nurse, student, or otherwise interested reader, the stories here will help you to understand how medicine works and how medical error can happen. The lifelong process of learning that is a medical career requires healthcare workers to find a way to live through these setbacks without either becoming too adept at putting them 'down to experience' and forgetting their social significance, or 'burning out' and leaving medicine. The stories and discussions here present detailed narratives, analyses, and reflections on medical errors through actions, omissions, and misunderstandings. They offer a uniquely honest perspective on the social implications of medical error and will enable healthcare workers at all levels to analyse and learn from it without losing sight of its impact.

This book presents a broad overview of the many intersections between health and the environment that lie at the basis of the most crucial environmental health issues, focusing on the responses provided by international and EU law. Consistent with the One Health approach and moving from the relevant international and EU legal frameworks, the book addresses some of the most important issues of environmental health including the traditional, such as pollution of air, water and soil and related food safety issues, as well as new and emerging challenges, like those linked to climate change, antimicrobial resistance and electromagnetic fields. Applying an intersectoral and interdisciplinary approach, it also investigates other branches of international and EU law including human rights law, investment law, trade law, energy law and disaster law. The work also discusses ethics and intergenerational equity. Ultimately, the book assesses the degree of effectiveness of the international and EU normative framework, and the extent to which the relevant legal instruments contribute to the protection of public health from major environmental hazards. The book will be a valuable resource for students, academics and policy makers working in the areas of Environmental Health law, Global Health law, International law and EU law.

This monograph makes a major new contribution to the historiography of criminal justice in England and Wales by focusing on the intersection of the history of law and crime with medical history. It does this through the lens provided by one group of historical actors, medical professionals who gave evidence in criminal proceedings. They are the means of illuminating the developing methods and personnel associated with investigating and prosecuting crime in the eighteenth and nineteenth centuries, when two linchpins of modern society, centralised policing and the adversarial criminal trial, emerged and matured. The book is devoted to two central questions: what did medical practitioners contribute to the investigation of serious violent crime in the period 1700 to 1914, and what impact did this have on the process of criminal justice? Drawing on the details of 2,600 cases of infanticide, murder and rape which occurred in central England, Wales and London, the book offers a comparative long-term perspective on medico-legal practice - that is, what doctors actually did when they were faced with a body that had become the object of a criminal investigation. It argues that medico-legal work developed in tandem with and was shaped by the needs of two evolving processes: pre-trial investigative procedures dominated successively by coroners, magistrates and the police; and criminal trials in which lawyers moved from the periphery to the centre of courtroom proceedings. In bringing together for the first time four groups of specialists - doctors, coroners, lawyers and police officers - this study offers a new interpretation of the processes that shaped the modern criminal justice system.

The first comprehensive Cannabis Handbook situated in an era when prohibition of marijuana has become more common in many US states and countries. Broad coverage The first comprehensive Cannabis Handbook situated in an era when prohibition of marijuana has become more common in many US states and countries. Broad coverage of the major topics in the field, especially those related to cannabis and various aspects of society. While many perspectives are represented, contributions include critical perspectives on legalization--pointing to issues that must be successfully managed by governments and other institutions. of the major topics in the field, especially those related to cannabis and various aspects of society. While many perspectives are represented, contributions include critical perspectives on legalization--pointing to issues that must be successfully managed by governments and other institutions.

Death Investigation: A Field Guide, Second Edition is updated and expanded to include a chronological analysis of the death scene investigative process from the first notification to the autopsy and final report. This book is written for the standpoints of a forensic pathologist and a forensic toxicologist emphasizing essential elements of the death investigation and how the results impact the final cause and manner of death. Topics discussed include how to assess the body at the scene and how to properly investigate natural and unnatural deaths. The book discusses various means and causes of deaths, demonstrating how death manifests in various parts of the body. A section on traumatic injuries examines and illustrates with color photographs blunt force, sharp force, gunshot wounds, and a host of other injuries that the investigator is likely to confront. Natural death conditions and disease are discussed in a separate chapter devoted to the most common manner of death. The Second Edition is fully updated with new added sections which cover forensic toxicology, statutory responsibilities, documentation and photography of the scene, DNA identification and possible contamination issues, decomposition, managing and utilizing electronic medical records, anaphylaxis and allergic reactions, infectious diseases such as Covid-19, acute peritonitis, and more. Despite including over 200 full-color photos, the book retains a succinct, handy format that is invaluable to those facing, and tasked with investigating, the reality of death on a day-to-day basis. Death Investigation: A Field Guide, Second Edition continues to serve as an invaluable resource for Crime Scene Investigators (CSIs), coroners, Medical Death Investigators (MDI), and medical examiner professionals.

* Examines an underresearched area of medical ethics; * Author are leading figures in field of medical law and ethics. Since 2011, they have been joint co Editor-in-Chief of the Medical Law Review.

Many workers in medicine, healthcare administration, science, and technology, no matter how strong their academic degrees or how distinguished their careers, find themselves baffled, frustrated, and even angered by their encounters with the law. Some of those occasions may lead to the need for a lawyer. But many of the bafflements and frustrations arise from ignorance about what the law is, including how it operates. Over more than a half century of inquiry into the relations between law and science, and through numerous conversations with physicians, scientists, and healthcare professionals whose work rests on technological development, the author realized that they often desire more knowledge about the operations of the law and the legal system. This book seeks to provide basic knowledge about the law in realms where these professionals often encounter it, primarily in areas where activities pose risks of personal injury. This book discusses two basic types of law: civil litigation and other remedies afforded to persons who ascribe injuries to the conduct or product of others, and direct regulation by the government of the levels of safety in those areas. Principal practical applications of this knowledge lie in ways to minimize risk, both in the primary sense and in efforts to avoid litigation over injuries, and in how to present arguments about policy to government officials who write laws and regulations.

Despite some significant advances in the creation and protection of rights affecting women's health, these do not always translate into actual health benefits for women. This collection asks: 'What is an effective law and what influences law's effectiveness or ineffectiveness? What dynamics, elements, and conditions come together to limit law's capacity to achieve instrumental goals for women's health and the advancement of women's health rights?' The book presents an integrated, co-referential and sustained critical discussion of the normative and constitutive reasons for law's limited effectiveness in the field of women's health. It offers comprehensive and cohesive explanatory accounts of law's limits and for the first time in the field, introduces a distinction between formal and substantive effectiveness of laws. Its approach is trans-systemic, multi-jurisdictional and comparative, with a focus on six countries in North America, Europe, Asia, and Africa and international human rights case law based on matters arising from Hungary, Portugal, Spain, Slovakia, the Czech Republic, Peru and Bolivia. The book will be a valuable resource for educators, students, lawyers, rights advocates and policymakers working in women's health, socio-legal studies, human rights, feminist legal studies, and legal philosophy more broadly.

The concept of deviance is complex, given that norms vary considerably across groups, times, and places. Society tends to primarily recognize traditional portraits of deviants such as street-offenders and drug addicts. The label "deviant" is commonly cast upon society's undesirables, but this socially constructed image often overlooks subtler-and arguably more dangerous-deviance. Physician malfeasance is an especially problematic form, given that medical professionals garner trust, autonomy, and prestige from society, which allows them to operate outside of the public eye. This book responds to a growing number of concerns regarding deviant physician actions such as physically and sexually abusive behaviors, fabricating medical findings and records, and taking advantage of patients (e.g., filing fraudulent Medicaid claims). It explores theoretical explanations for physician deviance, and goes on to consider potential responses such as Medicaid Fraud Control Units, the Questionable Doctors database, and the ability of doctors to police themselves. The unique perspective offered in this book informs discussions of white-collar crime and deviance and has important implications for researchers, policymakers, and students involved in criminal justice and public policy.

This book provides a practical guide for all those working in or with Medical Examiner Services in England and Wales. It is an adjunct to the e-learning and face-to-face training required to fulfil the Medical Examiner and Medical Examiner Officer roles. Medical Examiner Services also work closely with a wide range of stakeholders including bereavement and mortuary teams, Coroners and their Officers, Registrars, Funeral Directors and those working in clinical governance and patient safety. This book provides an essential overview of all aspects of the Medical Examiner system for anyone working in these areas, or in any aspect of the support and management of the deceased and bereaved. A concise guide including the knowledge base required to develop and run a Medical Examiner Service Content is completely aligned with required training Written by those with direct experience of establishing and working with Medical Examiner Services Relevant to a wide range of stakeholders who work with patients and the bereaved

This volume explores different models of regulating the use of restrictive practices in health care and disability settings. The authors examine the legislation, policies, inspection, enforcement and accreditation of the use of practices such as physical, mechanical and chemical restraint. They also explore the importance of factors such as organisational culture and staff training to the effective implementation of regulatory regimes. In doing so, the collection provides a solid evidence base for both the development and implementation of effective approaches to restrictive practices that focus on their reduction and, ultimately, their elimination across health care sectors. Divided into five parts, the volume covers new ground in multiple respects. First, it addresses the use of restrictive practices across mental health, disability and aged care settings, creating opportunities for new insights and interdisciplinary conversations across traditionally siloed sectors. Second, it includes contributions from research academics, clinicians, regulators and mental health consumers, offering a rich and comprehensive picture of existing regulatory regimes and options for designing and implementing regulatory approaches that address the failings of current systems. Finally, it incorporates comparative perspectives from Australia, New Zealand, the Netherlands, Germany and England. The book is an invaluable resource for regulators, policymakers, lawyers, clinicians, consumer advocates and academics grappling with the use and regulation of restrictive practices in mental health, disability and aged care contexts.

Forensic DNA Applications: An Interdisciplinary Perspective, Second Edition is fully updated to outline the latest advances in forensic DNA testing techniques and applications. It continues to fill the need for a reference book for people working in the field of forensic molecular biology testing and research as well as individuals investigating and adjudicating cases involving DNA evidence, whether they be civil or criminal cases. DNA techniques have greatly impacted obvious traditional forensic areas, but such advances have also positively affected myriad new areas of research and inquiry. It is possible today to think about solving forensic problems that were simply unheard of even a few years ago. As such, the book pulls all relevant research and applied science together into a detailed and comprehensive collection. Part I begins with the history and development of DNA typing and profiling for criminal and civil purposes. It discusses the statistical interpretation of results with case examples, mitochondrial DNA testing, Y single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs), and X SNP and STR testing. It also explores low copy number DNA typing, mixtures, and quality assurance and control. Part II moves on to cover the various uses and applications of analyzing collected physical evidence, victim identification in mass disasters, analyzing animal DNA, forensic botany, and other unique applications. Part III is dedicated to the latest advances and developments in human molecular biology and Part IV looks at policies and laws and ethics governing DNA evidence, and its utilization in various cases and the courts. Forensic DNA Applications, Second Edition covers cutting-edge research and advancements in the field and is the most up-to-date reference available. Edited and contributed to by the world's foremost leaders in the field, it is a must-have reference for established professionals, and an essential resource to legal professionals—lawyers and judges dealing with civil and criminal cases involving DNA technology—as well as students entering the fields of genetics and forensic DNA analysis.

Clinicians must practice medicine in conformity with regulatory requirements. That is the daily challenge, and those requirements have been founded on medical law. This book describes clinical law. A series of 62 brief commentaries are described, each setting out an important clinical legal case decided in an English court. The clinical relevance of the judgement is explained, together with how it should influence the care of the patient. Clinical readers are given skeleton guidance by their regulators, but almost no specific tuition as to how to apply it. This book sets out how clinical law has been applied in numerous cases, and thus provides guidance which is directly applicable to every clinician's practice in the United Kingdom. Although most court cases concentrate on the medical aspects of patients' care, the common currencies within clinical law touch on all clinical professions. Doctors, physiotherapists and others take consent every day; pharmacists must protect confidentiality; speech therapists consider the capacity of their patients; and nurses wrestle with discussions relating to whether their patients wish to be resuscitated The book is directed at members of the eight regulated clinical professions, the lawyers who deal with disputes, and all potential patients. About the Author Robert Wheeler, RCS MS LLB(Hons) LLM is a Consultant Neonatal and Paediatric Surgeon. He is the Associate Medical Director for the Department of Clinical Law, University Hospital of Southampton, Southampton Hampshire, England and Honorary Senior Lecturer, University of Southampton. https://www.uhs.nhs.uk/HealthProfessionals/Clinical-law-updates/Clinicallawupdates.aspx

Clinicians must practice medicine in conformity with regulatory requirements. That is the daily challenge, and those requirements have been founded on medical law. This book describes clinical law. A series of 62 brief commentaries are described, each setting out an important clinical legal case decided in an English court. The clinical relevance of the judgement is explained, together with how it should influence the care of the patient. Clinical readers are given skeleton guidance by their regulators, but almost no specific tuition as to how to apply it. This book sets out how clinical law has been applied in numerous cases, and thus provides guidance which is directly applicable to every clinician's practice in the United Kingdom. Although most court cases concentrate on the medical aspects of patients' care, the common currencies within clinical law touch on all clinical professions. Doctors, physiotherapists and others take consent every day; pharmacists must protect confidentiality; speech therapists consider the capacity of their patients; and nurses wrestle with discussions relating to whether their patients wish to be resuscitated The book is directed at members of the eight regulated clinical professions, the lawyers who deal with disputes, and all potential patients. About the Author Robert Wheeler, RCS MS LLB(Hons) LLM is a Consultant Neonatal and Paediatric Surgeon. He is the Associate Medical Director for the Department of Clinical Law, University Hospital of Southampton, Southampton Hampshire, England and Honorary Senior Lecturer, University of Southampton. https://www.uhs.nhs.uk/HealthProfessionals/Clinical-law-updates/Clinicallawupdates.aspx

The best storytellers and presenters know that a picture is worth a thousand words. Pictures simplify stories. They make stories memorable. They clarify complex concepts and they educate the audience in the easiest way. That is why attorneys work with artists-medical illustrators, to be exact. Injury Illustrated is the first book of its kind. It is the essential guide on medical illustrations used in the legal context. This book examines the creation of visual graphics known as demonstrative exhibits. These exhibits provide an understanding of traumatic injuries, surgeries, and radiology studies for the jury, judges, adjustors, mediators, and the attorneys. These chapters describe how to tell a clear story about gross anatomy, medical malpractice, and/or death investigation in court by using medical images. While medical illustration and injury law are very different professions, illustrators are the ideal partners for lawyers when solving problems and preparing for litigation. Divided into five sections, this book details who medical illustrators are, how they are educated in medicine, the skills and services they can provide to trial lawyers, and the countless benefits resulting from record review and case preparation. Find techniques to best use medical images during all stages of litigation Learn how graphic exhibits engage a jury and empower justice Understand why attorneys win more cases by collaborating with medical illustrators All readers will learn about this unique career and the attorney-illustrator relationship. More specifically, attorneys, artists, animators, law students, medical students, forensic scientists, and medical experts will understand how demonstrative exhibits assist legal proceedings in forensic matters and civil lawsuits. Warning; these images will be graphic and the cases at times will be catastrophic.

The best storytellers and presenters know that a picture is worth a thousand words. Pictures simplify stories. They make stories memorable. They clarify complex concepts and they educate the audience in the easiest way. That is why attorneys work with artists-medical illustrators, to be exact. Injury Illustrated is the first book of its kind. It is the essential guide on medical illustrations used in the legal context. This book examines the creation of visual graphics known as demonstrative exhibits. These exhibits provide an understanding of traumatic injuries, surgeries, and radiology studies for the jury, judges, adjustors, mediators, and the attorneys. These chapters describe how to tell a clear story about gross anatomy, medical malpractice, and/or death investigation in court by using medical images. While medical illustration and injury law are very different professions, illustrators are the ideal partners for lawyers when solving problems and preparing for litigation. Divided into five sections, this book details who medical illustrators are, how they are educated in medicine, the skills and services they can provide to trial lawyers, and the countless benefits resulting from record review and case preparation. Find techniques to best use medical images during all stages of litigation Learn how graphic exhibits engage a jury and empower justice Understand why attorneys win more cases by collaborating with medical illustrators All readers will learn about this unique career and the attorney-illustrator relationship. More specifically, attorneys, artists, animators, law students, medical students, forensic scientists, and medical experts will understand how demonstrative exhibits assist legal proceedings in forensic matters and civil lawsuits. Warning; these images will be graphic and the cases at times will be catastrophic.

The criminalisation of healthcare malpractice has become a highly topical and somewhat controversial question in recent years. Studies have demonstrated that in England and Wales, the trend towards holding healthcare professionals to account for malpractice is rapidly growing, abolishing the deference doctors enjoyed decades ago. The changing attitude of judges to claims for clinical negligence has been well documented. The role of the criminal process in England and Wales has been less fully analysed with the criminal law playing a very limited role until recently in the regulation of poor healthcare practice. In contrast, in France, the criminal process has for a long time been invoked more readily to respond to cases of healthcare malpractice, which involved even mere errors. This book compares English and French criminal law responses to healthcare malpractice and considers what lessons the French model can provide for potential reform in England and elsewhere. The book takes the HIV-contaminated blood episode as a primary example of the different approaches France and England have in dealing with healthcare malpractice. Kazarian emphasises the impact of rules of substantive criminal law and criminal procedure on the way in which healthcare malpractice is criminalised in a given country. This book explores the key lessons to be drawn on whether the criminal process is an appropriate means to respond to instances of healthcare malpractice. It proposes that features of French criminal law and criminal procedure might be useful to counteract healthcare malpractice.

Healthcare Ethics, Law and Professionalism: Essays on the Works of Alastair V. Campbell features 15 original essays on bioethics, and healthcare ethics specifically. The volume is in honour of Professor Alastair V. Campbell, who was the founding editor of the internationally renowned Journal of Medical Ethics, and the founding director of three internationally leading centres in bioethics, in Otago, New Zealand, Bristol, UK, and Singapore. Campbell was trained in theology and philosophy and throughout his career worked with colleagues from various disciplines, including law and various branches of healthcare. The diversity of topics and depth of contributors' insights reflect the breadth and impact of Campbell's philosophical work and policy contributions to healthcare ethics. Throughout his long academic career, Campbell's emphasis on healthcare ethics being practice-oriented, yet driven by critical reflection, has shaped the field in vital ways. The chapters are authored by leading scholars in healthcare ethics and law. Directly engaging with Campbell's work and influence, the essays discuss essential questions in healthcare ethics relating to its methodology and teaching, its intersection with law and policy, medical professionalism, religion, and its translation in different cultural settings. Chapters also grapple with specific enduring topics, such as the doctor-patient relationship, justice in health and biomedical research, and treatment of the human body and the dead.

Automatism is a notoriously difficult subject for law students, lawyers and judges. This book explores the science and medicine of sleep disorders and examines how the criminal process deals with such disorders when presented as a defence. It systematically examines the legal doctrines involved, and their implications for the use of the evidence key to establishing automatism, while also exploring the medical conditions that can cause automatism (particularly epilepsy, sleepwalking and diabetes). This book is a valuable resource for law students, lawyers, judges and expert witnesses.

Is the legal protection that is given to the expression of Abrahamic religious belief adequate or appropriate in the context of English medical law? This is the central question that is explored in this book, which develops a framework to support judges in the resolution of contentious cases that involve dissension between religious belief and medical law, developed from Alan Gewirth's Principle of Generic Consistency (PGC). This framework is applied to a number of medical law case studies: the principle of double effect, ritual male circumcision, female genital mutilation, Jehovah's Witnesses (adults and children) who refuse blood transfusions, and conscientious objection of healthcare professionals to abortion. The book also examines the legal and religious contexts in which these contentious cases are arbitrated. It demonstrates how human rights law and the proposed framework can provide a gauge to measure competing rights and apply legitimate limits to the expression of religious belief, where appropriate. The book concludes with a stance of principled pragmatism, which finds that some aspects of current legal protections in English medical law require amendment.

This book provides for an extensive legal analysis of the international drug control system in light of the growing challenges and criticism that this system faces. In the current debate on global drug policy, the central pillars of the international drug control system - the UN Drug Conventions as well as its institutions - are portrayed as outdated, suppressive and seen as an obstacle to necessary changes. The book's objective is to provide an in-depth and positivist insight into drug control's present legal framework and thus provide for a better understanding of the normative assumptions upon which drug control is currently based. This is attained by clarifying the objectives of the international drug control system and the premises by which these objectives are to be achieved. The objective of the current global framework of international drug control is the limitation of drugs to medical and scientific purposes. The meaning of this objective and its concrete implications for States' parties as well as its problems from the perspective of other regimes of international law, most notably international human rights law, are extensively analysed. Additionally, the book focuses on how the international drug control system attempts to reach the objective of confining drugs to medical and scientific purposes, i.e. by setting up a universal system that exercises a rigid control on drug supply. The consequences of this heavy focus on the reduction of drug supply are outlined, and the book concludes by making suggestions on how the international drug control system could be reformed in the near future in order to better meet the existing challenges. The analysis occurs from a general international law perspective. It aims to map the international drug control system within a wider context of international law and to understand whether the problems that the international drug control system faces are exemplary for the difficulties that institutionalized systems of global scope face in the twenty-first century.

This book celebrates Professor Margaret Brazier's outstanding contribution to the field of healthcare law and bioethics. It examines key aspects developed in Professor Brazier's agenda-setting body of work, with contributions being provided by leading experts in the field from the UK, Australia, the US and continental Europe. They examine a range of current and future challenges for healthcare law and bioethics, representing state-of-the-art scholarship in the field. The book is organised into five parts. Part I discusses key principles and themes in healthcare law and bioethics. Part II examines the dynamics of the patient-doctor relationship, in particular the role of patients. Part III explores legal and ethical issues relating to the human body. Part IV discusses the regulation of reproduction, and Part V examines the relationship between the criminal law and the healthcare process. Chapter 10 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 3.0 license. https://s3-us-west-2.amazonaws.com/tandfbis/rt-files/docs/Open+Access+Chapters/9781138861091_oachapter10.pdf