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Mercury underwent global contraction due to the sustained cooling of the planet. Positive‐relief landforms, found widespread across Mercury, are thought to be the surface expressions of thrust faults accommodating the contraction. Disagreement exists in the literature on the amount of contraction, with estimates of radius change ranging from ∼1 to 7 km. These differences solely arise from the method used to estimate the fault population strain, which relies on the number of structures. Here, we adapt a previous framework by which the continuum approximation to shortening strains can be determined from fault length and displacement statistics for an incompletely sampled fault population. We apply this method to three data sets that sample different numbers of faults. Our results show that even for conservative fault parameters, 2 to 3.5 km of radial contraction are returned, irrespective of the data set used, and thus resolve the debate on the amount of global contraction on Mercury. Plain Language Summary The planet Mercury has shrunk due to the long, sustained cooling of its interior. This process has led to the development of faults to accommodate the shrinking in the cold uppermost rocky parts of the planet. Multiple studies use the uplifted topography that overlie these faults to estimate the amount Mercury has shrunk. However, these studies are in disagreement with one another due to the number of landforms that each study attributes to global contraction. Here, we use an alternate approach of calculating the change in volume caused by a population of faults by statistically scaling the change from the largest fault to the entire fault population. From the literature, we use three fault data sets with noticeably different numbers of structures that previously showed the disagreement. The method in this study produces results that are comparable to one another, resolving the long‐standing disagreement in the literature. Our results find that at least three kilometers of change in Mercury's radius occurred for a conservative set of fault‐geometric parameters. Therefore, this newly applied method should replace the previous approach to estimate the amount by which Mercury has shrunk. Key Points We implement a method to estimate contractional fault strain independent of the number of faults considered We resolve the long‐standing disagreement of the amount of Mercury's global contraction Our results indicate Mercury radially contracted by multiple kilometers for a wide range of fault geometries and depths

Head and neck squamous cell carcinoma (HNSCC) represents an aggressive and heterogenous group of cancers whose pathologies remain largely unresolved. Despite recent advances in HNSCC therapeutic strategies, the overall survival of HNSCC patients remains poor and continues to prompt efforts to develop more effective therapies. Exosomes are a subtype of extracellular vesicles secreted by a variety of cells that have begun to spark significant interest in their roles in cancer. As membranous vesicles, spanning from 30–150 nm in diameter, exosomes mediate the transport of various molecules, such as proteins, nucleic acids, and lipids, intercellularly throughout the body. In doing so, exosomes not only act to deliver materials to cancer cells but also as signals that can confer their progression. Accumulating evidence shows the direct correlation between exosomes and the aggressiveness of HNSCC. However, more research is warranted in this field to further our understanding. In this review, we attempt to highlight the tumor-supporting roles and therapeutic potential of exosomes in HNSCC. We introduce first the biogenesis and component features of exosomes, followed by their involvement in HNSCC proliferation and metastasis. We then move on to discuss HNSCC-derived exosomes’ influence on the tumor microenvironment and their function in tumor drug resistance. Finally, we explore the promising potential of exosomes as HNSCC biomarkers and therapeutic targets and drug carriers for HNSCC treatments.

A search is presented for the pair production of new heavy resonances, each decaying into a top quark (t) or antiquark and a gluon (g). The analysis uses data recorded with the CMS detector from proton–proton collisions at a center-of-mass energy of 13 Te V at the LHC, corresponding to an integrated luminosity of 138 fb - 1 . Events with one muon or electron, multiple jets, and missing transverse momentum are selected. After using a deep neural network to enrich the data sample with signal-like events, distributions in the scalar sum of the transverse momenta of all reconstructed objects are analyzed in the search for a signal. No significant deviations from the standard model prediction are found. Upper limits at 95% confidence level are set on the product of cross section and branching fraction squared for the pair production of excited top quarks in the t ∗ → tg decay channel. The upper limits range from 120 to 0.8 fb for a t ∗ with spin-1/2 and from 15 to 1.0 fb for a t ∗ with spin-3/2. These correspond to mass exclusion limits up to 1050 and 1700 Ge V for spin-1/2 and spin-3/2 t ∗ particles, respectively. These are the most stringent limits to date on the existence of t ∗ → tg resonances.

The CMS detector, including its muon system, has been operating at the CERN LHC in increasingly challenging conditions for about 15 years. The muon detector was designed to provide excellent triggering and track reconstruction for muons produced in proton–proton collisons at an instantaneous luminosity (𝓛) of 1 x 1034 cm–2 s–1. During the Run 2 data-taking period (2015–2018), the LHC achieved an instantaneous luminosity of twice its design value, resulting in larger background rates and making the efficient detection of muons more difficult. While some backgrounds result from natural radioactivity, cosmic rays, and interactions of the circulating protons with residual gas in the beam pipe, the dominant source of background hits in the muon system arises from proton–proton interactions themselves. Charged hadrons leaving the calorimeters produce energy deposits in the muon chambers. In addition, high-energy particles interacting in the hadron calorimeter and forward shielding elements generate thermal neutrons, which leak out of the calorimeter and shielding structures, filling the CMS cavern. We describe the method used to measure the background rates in the various muon subsystems. These rates, in conjunction with simulations, can be used to estimate the expected backgrounds in the High-Luminosity LHC. This machine will run for at least 10 years starting in 2029 reaching an instantaneous luminosity of 𝓛 = 5 x 1034 cm–2 s–1 and increasing ultimately to 𝓛 = 7.5 x 1034 cm–2 s–1. These background estimates have been a key ingredient for the planning and design of the muon detector upgrade.

\"Analyzes the potential costs and benefits of school choice and discusses policy mechanisms that would maximize its benefits while mitigating its social costs, specifically in terms of racial and religious issues and the promotion of civic values.\" (Provided by publisher).

On the assumption that some of the characteristics of sclerophyllous leaves may have a nutritional basis, data on the leaf composition of nineteen species from evergreen bushland in Jamaica are compared with published data on the leaf composition of thirty-one species of mesophytes from Central America. The data show that in terms of dry matter a sclerophyllous leaf is associated with a decrease in percentage protein content rather than with an increase in percentage fibre content. There is a highly significant positive correlation between the protein and phosphorus contents of the leaves considered, and it is suggested that the ability to tolerate low phosphate may characterize sclerophyllous vegetation in general.

A statistical analysis is made of published data on the leaf composition of eighty-nine species, covering both sclerophyllous and mesophytic types of leaves, from North and Central America, Africa, and India. Expressing degree of sclerophylly by the ratio crude fibre dry weight × 100/crude protein dry weight, the analysis shows: (1) that in terms of organic matter an increase in sclerophylly is associated with a decrease in percentage protein content and with an increase in percentage fibre content, and (2) that in terms of mineral matter a decrease in phosphorus content below about 0.3 per cent. results in a proportional increase in degree of sclerophylly. These two results are considered complementary. Since phosphorus is essential for protein synthesis, the observed protein deficiency of sclerophyllous leaves can be correlated with their low phosphorus content. It is also reasonable to expect the observed reciprocal relationship between protein content and fibre content on the basis of a common pool of intermediate metabolites. The above conclusions support the author's hypothesis, suggested in a previous paper, that a sclerophyllous leaf is the expression of a metabolism found in plants that can tolerate low levels of phosphate. Strong circumstantial evidence is also provided by the fact that phosphate deficiency is characteristic of the soils, either wet or dry, which carry sclerophyllous vegetation. The hypothesis thus provides a ready answer to the apparent paradox of why the same specialized type of leaf should occur in both wet and dry habitats.

A study was conducted to determine the effects of storage at constant temperatures upon the survival of protoscolices of Echinococcus granulosus from hydatid cysts removed from infected sheep. Parallel tests were conducted on intact cysts from both lung and liver, and on protoscolices stored within 1-ml samples of hydatid fluid. The longest survival times of any of the samples tested at each temperature were: -20 C, 1 hr; -10 C, 4 hr; 1 C, 16 days; 10 C, 16 days; 20 C, 8 days; 30 C, 4 days; 40 C, 2 days, and 50 C, 2 hr. In general, protoscolices survived considerably better when stored within intact cysts than when in 1 ml of hydatid fluid. At temperature ranges where putrefaction occurred, protoscolices in cysts from lung survived longer than those from liver. The ability of these protoscolices to survive extended periods of time after an infected sheep has died or been killed suggests that stringent preventive and control measures should be established in areas where hydatid disease is endemic. Animal pits at community dumping grounds where sheep carcasses might be discarded should be enclosed or covered, and all stray and roving dogs in those regions should be rigidly controlled.

The 2002 No Child Left Behind Act is the most important legislation in American education since the 1960s. The law requires states to put into place a set of standards together with a comprehensive testing plan designed to ensure these standards are met. Students at schools that fail to meet those standards may leave for other schools, and schools not progressing adequately become subject to reorganization. The significance of the law lies less with federal dollar contributions than with the direction it gives to federal, state, and local school spending. It helps codify the movement toward common standards and school accountability. Yet NCLB will not transform American schools overnight. The first scholarly assessment of the new legislation, No Child Left Behind? breaks new ground in the ongoing debate over accountability. Contributors examine the law's origins, the political and social forces that gave it shape, the potential issues that will surface with its implementation, and finally, the law's likely consequences for American education.