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\"Public Security in Federal Polities is the first systematic and methodical study to bring together the fields of security studies and comparative federalism. The volume explores the symbiotic relationship between public security concerns and institutional design, public administration, and public policy across nine federal country case studies: Brazil, Canada, Germany, India, Mexico, South Africa, Spain, Switzerland, and the United States. In addressing specific national security concerns and aspects of globalization that are challenging conventional approaches to global, international, regional, and domestic security, this volume examines how the constitutional and institutional framework of a society affects the effectiveness and efficiency of public security arrangements. Public Security in Federal Polities identifies differences and similarities, highlights best practices, and draws out lessons for both particular federations, and for federal systems in general. This book is essential reading for scholars, students, practitioners as well as policy- and decision-makers of security and federalism.\"-- Provided by publisher.

Sulfur dioxide–sulfites (E 220–228) were re‐evaluated in 2016, resulting in the setting of a temporary ADI of 0.7 mg SO2 equivalents/kg bw per day. Following a European Commission call for data, the present follow‐up opinion assesses data provided by interested business operators (IBOs) and additional evidence identified in the publicly available literature. No new biological or toxicological data addressing the data gaps described in the re‐evaluation were submitted by IBOs. Taking into account data identified from the literature search, the Panel concluded that there was no substantial reduction in the uncertainties previously identified in the re‐evaluation. Therefore, the Panel considered that the available toxicity database was inadequate to derive an ADI and withdrew the current temporary group acceptable daily intake (ADI). A margin of exposure (MOE) approach was considered appropriate to assess the risk for these food additives. A lower confidence limit of the benchmark dose of 38 mg SO2 equivalents/kg bw per day, which is lower than the previous reference point of 70 mg SO2 equivalents/kg bw per day, was estimated based on prolonged visual evoked potential latency. An assessment factor of 80 was applied for the assessment of the MoE. At the estimated dietary exposures, when using a refined exposure scenario (Data set D), MOEs at the maximum of 95th percentile ranges were below 80 for all population groups except for adolescents. The dietary exposures estimated using the maximum permitted levels would result in MOEs below 80 in all population groups at the maximum of the ranges of the mean, and for most of the population groups at both minimum and maximum of the ranges at the 95th percentile. The Panel concluded that this raises a safety concern for both dietary exposure scenarios. The Panel also performed a risk assessment for toxic elements present in sulfur dioxide–sulfites (E 220–228), based on data submitted by IBOs, and concluded that the maximum limits in the EU specifications for arsenic, lead and mercury should be lowered and a maximum limit for cadmium should be introduced.

In this randomized, controlled trial, the number of angioedema attacks per month was approximately 75% lower among adults with hereditary angioedema who received a CRISPR-Cas9–based therapy than among those who received placebo.

\"Naamiwan's Drum follows the story of a famous Ojibwe medicine man, his gifted grandson, and remarkable water drum. This drum, and forty other artefacts, were given away by a Canadian museum to an American Anishinaabe group that had no family or community connections to the collection. Many years passed before the drum was returned to the family and only half of the artefacts were ever returned to the museum.\"-- Provided by publisher.

The EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) was asked to deliver a scientific opinion re‐evaluating sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228) when used as food additives. The Panel noted that sulfur dioxide, bisulfite and sulfite ions existed in a series of equilibria and that these would favour bisulfite ions at the pH of the stomach and sulfite ions at physiological pHs. Therefore, it was considered that once ingested, based on their capacity to form sulfite ions, read across between the different sulfite sources is possible; however, the Panel noted the uncertainties about the reactivity of sulfites in different foods and the resulting reaction products. The overall limited database did not indicate any concern for genotoxicity and did not report any effect in the available chronic, carcinogenicity and reprotoxicity studies after oral exposure in the diet, by gavage, or in the drinking water. A no observed adverse effect level (NOAEL) of 70 mg SO2 equivalent/kg body weight (bw) per day was identified from a long‐term toxicity study in rats. However, the Panel noted several uncertainties and limitations in the database and concluded that the current group acceptable daily intake (ADI) of 0.7 mg SO2 equivalent/kg bw per day (derived using a default uncertainty factor) would remain adequate but should be considered temporary while the database was improved. The Panel recommended that the database and the temporary group ADI should be re‐evaluated and noted that the recommended studies could require 5 years for completion. The Panel further concluded that exposure estimates to sulfur dioxide and sulfites were higher than the group ADI of 0.7 mg SO2 equivalent/kg bw per day for all population groups.

\"Policies forged by all levels of government affect the lives of urban residents. Contributors to this volume explore how intergovernmental relations shape urban policies and how various social forces are involved in--or excluded from--the policy process. Focusing on diverse policy fields including emergency planning, image-building, immigrant settlement, infrastructure, federal property, and urban Aboriginal policy, Sites of Governance presents detailed studies of the largest city in each of Canada's provinces. Drawing on extensive documentary research and hundreds of interviews, contributors offer rich, nuanced analyses and a wealth of policy cases, ranging from preparation for the Vancouver 2010 Olympics to the development of innovative immigrant settlement programming in Winnipeg. Dominant themes include the importance of resources and formal jurisdiction in multilevel policy making, and the struggle for influence between business interests and other social forces. Essential reading for anyone concerned with the quality of urban life in Canada, Sites of Governance offers important insights about how multilevel governance works in Canadian cities.\"--Publisher's website.

The class 2 type V CRISPR effector Cas12 is thought to have evolved from the IS200/IS605 superfamily of transposon-associated TnpB proteins 1 . Recent studies have identified TnpB proteins as miniature RNA-guided DNA endonucleases 2 , 3 . TnpB associates with a single, long RNA (ωRNA) and cleaves double-stranded DNA targets complementary to the ωRNA guide. However, the RNA-guided DNA cleavage mechanism of TnpB and its evolutionary relationship with Cas12 enzymes remain unknown. Here we report the cryo-electron microscopy (cryo-EM) structure of Deinococcus radiodurans ISDra2 TnpB in complex with its cognate ωRNA and target DNA. In the structure, the ωRNA adopts an unexpected architecture and forms a pseudoknot, which is conserved among all guide RNAs of Cas12 enzymes. Furthermore, the structure, along with our functional analysis, reveals how the compact TnpB recognizes the ωRNA and cleaves target DNA complementary to the guide. A structural comparison of TnpB with Cas12 enzymes suggests that CRISPR–Cas12 effectors acquired an ability to recognize the protospacer-adjacent motif-distal end of the guide RNA–target DNA heteroduplex, by either asymmetric dimer formation or diverse REC2 insertions, enabling engagement in CRISPR–Cas adaptive immunity. Collectively, our findings provide mechanistic insights into TnpB function and advance our understanding of the evolution from transposon-encoded TnpB proteins to CRISPR–Cas12 effectors. Cryo-electron microscopy analysis of the Deinococcus radiodurans ISDra2 TnpB in complex with its cognate ωRNA and target DNA provides insights into the mechanism of TnpB function and the evolution of CRISPR–Cas12 effectors.

The CRISPR-associated protein Cpf1 from Francisella novicida is a novel enzyme with specific, dual-endoribonuclease–endonuclease activities in precursor crRNA processing and crRNA-programmable cleavage of target DNA. Cpf1 enzyme in CRISPR immunity The bacterial immune system, CRISPR, utilizes a small RNA guide, or crRNA, to target a nucleolytic CRISPR complex to DNA with a complementary sequence. This process has been widely exploited for various types of genome engineering. Previously described CRISPR systems utilize one nuclease, such as Cas6, to generate the mature crRNA, and a second, such as Cas9, to cleave the target DNA. Two studies illustrate a different approach that involves the Cpf1 protein. Emmanuelle Charpentier and colleagues report that type V-A Cpf1 protein from Francisella novicida functions as a minimalistic CRISPR system. It is a dual-nuclease enzyme that can perform both the pre-crRNA processing and DNA cleavage activities, having distinct active domains for the two substrates. Zhiwei Huang and colleagues solve the crystal structure of monomeric Lachnospiraceae bacterium Cpf1 protein bound to crRNA, showing how binding induces conformational changes in the nuclease. CRISPR–Cas systems that provide defence against mobile genetic elements in bacteria and archaea have evolved a variety of mechanisms to target and cleave RNA or DNA 1 . The well-studied types I, II and III utilize a set of distinct CRISPR-associated (Cas) proteins for production of mature CRISPR RNAs (crRNAs) and interference with invading nucleic acids. In types I and III, Cas6 or Cas5d cleaves precursor crRNA (pre-crRNA) 2 , 3 , 4 , 5 and the mature crRNAs then guide a complex of Cas proteins (Cascade-Cas3, type I; Csm or Cmr, type III) to target and cleave invading DNA or RNA 6 , 7 , 8 , 9 , 10 , 11 , 12 . In type II systems, RNase III cleaves pre-crRNA base-paired with trans -activating crRNA (tracrRNA) in the presence of Cas9 (refs 13 , 14 ). The mature tracrRNA–crRNA duplex then guides Cas9 to cleave target DNA 15 . Here, we demonstrate a novel mechanism in CRISPR–Cas immunity. We show that type V-A Cpf1 from Francisella novicida is a dual-nuclease that is specific to crRNA biogenesis and target DNA interference. Cpf1 cleaves pre-crRNA upstream of a hairpin structure formed within the CRISPR repeats and thereby generates intermediate crRNAs that are processed further, leading to mature crRNAs. After recognition of a 5′-YTN-3′ protospacer adjacent motif on the non-target DNA strand and subsequent probing for an eight-nucleotide seed sequence, Cpf1, guided by the single mature repeat-spacer crRNA, introduces double-stranded breaks in the target DNA to generate a 5′ overhang 16 . The RNase and DNase activities of Cpf1 require sequence- and structure-specific binding to the hairpin of crRNA repeats. Cpf1 uses distinct active domains for both nuclease reactions and cleaves nucleic acids in the presence of magnesium or calcium. This study uncovers a new family of enzymes with specific dual endoribonuclease and endonuclease activities, and demonstrates that type V-A constitutes the most minimalistic of the CRISPR–Cas systems so far described.