Background/Context College grades can influence a student's graduation prospects, academic motivation, postgraduate job choice, professional and graduate school selection, and access to loans and scholarships. Despite the importance of grades, national trends in grading practices have not been examined in over a decade, and there has been a limited effort to examine the historical evolution of college grading. Purpose/Objective/Research Question/Focus of Study Here we look at the evolution of grading over time and space at American colleges and universities over the last 70 years. Our data provide a means to examine how instructors’ assessments of excellence, mediocrity, and failure have changed in higher education. Data Collection and Analysis We have collected historical and contemporary data on A–F letter grades awarded from over 200 four-year colleges and universities. Our contemporary data on grades come from 135 schools, with a total enrollment of 1.5 million students. Research Design Through the use of averages over time and space as well as regression models, we examine how grading has changed temporally and how grading is a function of school selectivity, school type, and geographic region. Findings/Results Contemporary data indicate that, on average across a wide range of schools, A's represent 43% of all letter grades, an increase of 28 percentage points since 1960 and 12 percentage points since 1988. D's and F's total typically less than 10% of all letter grades. Private colleges and universities give, on average, significantly more A's and B's combined than public institutions with equal student selectivity. Southern schools grade more harshly than those in other regions, and science and engineering-focused schools grade more stringently than those emphasizing the liberal arts. At schools with modest selectivity, grading is as generous as it was in the mid-1980s at highly selective schools. These prestigious schools have, in turn, continued to ramp up their grades. It is likely that at many selective and highly selective schools, undergraduate GPAs are now so saturated at the high end that they have little use as a motivator of students and as an evaluation tool for graduate and professional schools and employers. Conclusions/Recommendations As a result of instructors gradually lowering their standards, A has become the most common grade on American college campuses. Without regulation, or at least strong grading guidelines, grades at American institutions of higher learning likely will continue to have less and less meaning.

Findings/Results: Contemporary data indicate that, on average across a wide range of schools, A’s represent 43% of all letter grades, an increase of 28 percentage points since 1960 and 12 percentage points since 1988. D’s and F’s total typically less than 10% of all letter grades. Private colleges and universities give, on average, significantly more A’s and B’s combined than public institutions with equal student selectivity. Southern schools grade more harshly than those in other regions, and science and engineering-focused schools grade more stringently than those emphasizing the liberal arts. At schools with modest selectivity, grading is as generous as it was in the mid-1980s at highly selective schools. These prestigious schools have, in turn, continued to ramp up their grades. It is likely that at many selective and highly selective schools, undergraduate GPAs are now so saturated at the high end that they have little use as a motivator of students and as an evaluation tool for graduate and professional schools and employers.

The permeability of continental crust is so highly variable that it is often considered to defy systematic characterization. However, despite this variability, some order has been gleaned from globally compiled data. What accounts for the apparent coherence of mean permeability in the continental crust (and permeability–depth relations) on a very large scale? Here we argue that large-scale crustal permeability adjusts to accommodate rates of internal and external forcing. In the deeper crust, internal forcing – fluxes induced by metamorphism, magmatism, and mantle degassing – is dominant, whereas in the shallow crust, external forcing – the vigor of the hydrologic cycle – is a primary control. Crustal petrologists have long recognized the likelihood of a causal relation between fluid flux and permeability in the deep, ductile crust, where fluid pressures are typically near-lithostatic. It is less obvious that such a relation should pertain in the relatively cool, brittle upper crust, where nearhydrostatic fluid pressures are the norm. We use first-order calculations and numerical modeling to explore the hypothesis that upper-crustal permeability is influenced by the magnitude of external fluid sources, much as lower-crustal permeability is influenced by the magnitude of internal fluid sources. We compare model-generated permeability structures with various observations of crustal permeability.

Tackling grade inflation in US universitiesSolutions could include reporting the class average and ranking departments by results.

Field data from Upper Geyser Basin, Yellowstone, indicate that geyser frequency is less sensitive to elastic deformation than might be surmised from a review of the literature. Earth‐tide influences are not identifiable in any of the geysers we monitored. Though atmospheric‐pressure influences are observed, only long‐period variations on the order of 5 mBars or greater seem to influence geyser frequency. Long‐distance interconnections between geysers are common and add to the difficulty of identifying strain influences. Additional variations in geyser periodicity may be governed by the internal dynamics of the geysers rather than external influences.

Using bias‐corrected Nexrad precipitation estimates and spatial statistics of rainfall intensity, we examine the influence of irrigation on summer precipitation in the Texas High Plains. In this region, human alteration of the surface water and energy balance has been extreme. Irrigation enhances precipitation downwind, yielding storms of greater duration, length, and accumulation. Irrigation water is not a significant source of moisture feeding precipitation; rather, the cool, wet surface increases low‐level instability, triggering storms. We estimate that an additional 6% to 18% of summer precipitation attributable to irrigation falls ∼90 km downwind of the irrigated region.

Bangladesh is situated in a subtropical to tropical climatic zone. A recently weathered crust has developed on sedimentary bedrock (sandstone, siltstone, shale and claystones) of Tertiary–Quaternary age. Weathered samples were collected from 16 sections totaling 68 samples and were analyzed mineralogically. The main primary minerals identified in the weathered crust of sedimentary rocks are quartz, plagioclase, K-feldspar, biotite, muscovite, sparse carbonate and epidote. The secondary minerals are kaolinite, illite, chlorite, gibbsite and goethite. Weathering initiated along the grain boundaries and cleavage planes of the minerals, forming small cloudy materials which were very difficult to identify. In the advanced stage of weathering, these cloudy materials have turned into secondary minerals. In region 1, high rain fall (7100mm/yr) and monsoonic climate resulted in a kaolinite–gibbsite–goethite suite through the weathering of feldspars and biotite. The occurrence of gibbsite in the relatively elevated lands of Sylhet and Fe-kaolinite throughout the study areas is indicative of a humid–tropical climate during formation of the weathered crust.

An ancient saprolite has developed on the Palaeoproterozoic granulite, granite gneiss and amphibolite bedrock of the Vuotso–Tankavaara area of central Finnish Lapland. The present day climatic regime in Finnish Lapland lies within the northern boreal zone and so the saprolite there can be regarded as fossil. Cores of saprolite were collected from 4 sections (42 samples) and analyzed chemically and mineralogically. In the study area, progressive weathering of the rocks has been marked by gradual enrichment in Al, Fe and Ti; and depletion of Na, K and Ca. The higher concentration of Fe(III) and water and reduced Na and Ca in weathered bedrock in the 4 sections are indicative of oxidation, hydration and leaching processes involved during weathering. The primary minerals in the saprolite are plagioclase feldspar, K-feldspar, quartz, garnet (almandine) and hornblende; the common secondary minerals are kaolinite, halloysite, and vermiculite in addition to minor amounts of sericite. Intense weathering is indicated by: (1) the presence of kaolinite and halloysite in 4 sections of different bedrock types, and (2) the comparatively lower SiO2/Al2O3 (wt.%) ratio (2.30) of weathered granulites (3 sections) as compared to fresh granulite (4.33) and that of weathered amphibolite (2.68) as compared to fresh amphibolite (3.56). In general, kaolinite and halloysite have formed through the weathering of feldspars, garnet, and biotite. Vermiculite is the most probable alteration product of biotite. The formation of kaolinite and halloysite in Finnish Lapland indicates wetter and warmer climatic conditions during the time of their formation than at present. The possible time for formation of the saprolite is early Cretaceous–early Tertiary into Middle Miocene.

The fraction of total plant growth or net primary production (NPP) appropriated by humans, often referred to as human appropriation of net primary production (HANPP), is among the most widely used measures to assess the “human domination of Earth's ecosystems” ([1][1]). S. Rojstaczer et al. (“