What We See,What We Do Not See,and What We Do Not Want to See in HLA Class I Immunopeptidomes

The identification of peptides bound to human leukocyte antigen class I (HLA‐I) molecules—that is, the HLA‐I immunopeptidome—is a useful tool in the hunt for epitopes suitable for vaccinations and immunotherapies. These peptides are mainly generated by proteasomes through peptide hydrolysis and peptide splicing. In this issue, Nicastri and colleagues compared different methods for the elution of HLA class I‐associated peptides. It is demonstrated that the choice of HLA‐associated peptide enrichment and purification strategy affects peptide yields and creates a bias in detected sequence repertoire. The author carried out this technical brief through the analysis of canonical non‐spliced peptides. However, their study left out any analysis of post‐translationally spliced peptides, thereby missing an opportunity to shed light on the persistent debate of the frequency of these unconventional peptides.     

What We Do Not Know About Differentiation

The outstanding recent advances in the analysis of differentiationare in concept and method. In this paper examples are providedto demonstrate that formulation of the problem of differentiationin terms of biosynthesis and its control poses questions innew and more manageable ways. As examples, reference will bemade to: (1) the question of control of the sets of specializedproperties by which we define a cell type; (2) propagabilityof differentiated states; (3) developmental bias in relationto intracellular events; and (4) the mechanisms of extrinsiccontrol of differentiation. Particular attention, also, willbe focused on the relationship of morphogenetic to biosyntheticevents.     

What Do We Know About Metal Recycling Rates?

The recycling of metals is widely viewed as a fruitful sustainability strategy, but little information is available on the degree to which recycling is actually taking place. This article provides an overview on the current knowledge of recycling rates for 60 metals. We propose various recycling metrics, discuss relevant aspects of recycling processes, and present current estimates on global end‐of‐life recycling rates (EOL‐RR; i.e., the percentage of a metal in discards that is actually recycled), recycled content (RC), and old scrap ratios (OSRs; i.e., the share of old scrap in the total scrap flow). Because of increases in metal use over time and long metal in‐use lifetimes, many RC values are low and will remain so for the foreseeable future. Because of relatively low efficiencies in the collection and processing of most discarded products, inherent limitations in recycling processes, and the fact that primary material is often relatively abundant and low‐cost (which thereby keeps down the price of scrap), many EOL‐RRs are very low: Only for 18 metals (silver, aluminum, gold, cobalt, chromium, copper, iron, manganese, niobium, nickel, lead, palladium, platinum, rhenium, rhodium, tin, titanium, and zinc) is the EOL‐RR above 50% at present. Only for niobium, lead, and ruthenium is the RC above 50%, although 16 metals are in the 25% to 50% range. Thirteen metals have an OSR greater than 50%. These estimates may be used in considerations of whether recycling efficiencies can be improved; which metric could best encourage improved effectiveness in recycling; and an improved understanding of the dependence of recycling on economics, technology, and other factors.     

How Many Acute Beds Do We Really Need?

At the end of 1972 two new “best-buy” district general hospitals should open at Bury St. Edmunds and Frimley, eventually serving their catchment areas at a ratio of two acute beds per 1,000 population. This study shows that one of these areas is already operating below this projected target as a result of a considerable decline in the bed ratio over the past decade. Drastic shortening of the average length of stay has permitted an increase in admission rates from 60 to 79 per 1,000 population over the decade, while costs per case measured at constant prices have fallen. These changes have taken place more rapidly than in the U.K. generally. The evidence points to the pattern of clinical management as the main reason for this and suggests that similar gains could be achieved on a national scale, even without waiting for new buildings and expanded community services.     

Diversity of Organisms: How Much Do We Know?

The history of Invertebrate Zoology over the past 40 years canbe used to illustrate interest in organisms and some of theways in which the symposium's question may be interpreted. Thestudy of animal organisms from a holistic perspective has progressedenormously as reflected in changes in described and estimatednumbers of species, in the discovery of new higher taxa andin the growth of literature. Generalizations on the biologyof animal organisms, however, rest on relatively small samples,and many of the same organisms that have received the most attentionin the past continue to receive the most today. Symbiosis andcolonial organization have been two important means wherebynew organizational levels for organisms have evolved. Ultrastructuralresearch over the past 20 years has provided new evidence insupport of the hypothesis promulgated long ago that multicellularanimals (metazoans) may have evolved from colonial protistans.Some polymorphic, colonial metazoans have approached or crossedthe threshold to a still more complex level of organism.     

如何履行“保护第一”的承诺

<正>在长白山加速发展的过程中,生态保护与开发建设之间的矛盾日益凸显,新一届管委会负责人提出要把保护好长白山的原生态作为首要任务,"切实做到保护面前再大的利益不动摇,再小的生态不破坏"。但能否落实"保护第一"的承诺,不取决于良好的愿望,而取决于在工作实践中遵循的理念和准则是否正确,采取的措施是否得当。     

How Old is Earth,and How Do We Know?

Earth scientists have devised many complementary and consistent techniques to estimate the ages of geologic events. Annually deposited layers of sediments or ice document hundreds of thousands of years of continuous Earth history. Gradual rates of mountain building, erosion of mountains, and the motions of tectonic plates imply hundreds of millions of years of change. Radiometric dating, which relies on the predictable decay of radioactive isotopes of carbon, uranium, potassium, and other elements, provides accurate age estimates for events back to the formation of Earth more than 4.5 billion years ago. These and other dating techniques are mutually consistent and underscore the reality of “deep time” in Earth history.