A Refined Regional Model for Estimating Pressure, Temperature, and Water Vapor Pressure for Geodetic Applications in China

Pressure, temperature, and water vapor pressure are basic meteorological parameters that are frequently required in Global Navigation Satellite System (GNSS) positioning/navigation and GNSS meteorology. Although models like Global Pressure and Temperature (GPT) and Global Pressure and Temperature 2 wet (GPT2w) were developed for these demands, their spatial resolutions are lower than 0.75° and temporal resolutions are below 6 h, which limits their achievement. The publication of European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 hourly 0.25° × 0.25° data offers the opportunity to lift this limitation. In this work, the ERA5 surface data are used to evaluate the temporal variabilities of pressure, temperature, and water vapor pressure in the area of China. We characterize their diurnal variations using hourly data and take into account their geographical variations by 0.25° × 0.25° grids. In addition, we improve the height corrections for the three parameters employing the ERA5 pressure level data. Through these efforts, we build a new regional model named Chinese pressure, temperature, and water vapor pressure (CPTw), which has the advanced resolution of 0.25° × 0.25° and temporal resolution of 1 h. We evaluate the performance using ERA5 data and radiosonde data compared with the approved GPT2w model. Results demonstrate that the accuracies of the new model are superior to the GPT2w model in all meteorological parameters. The validation with the radiosonde data shows RMS for pressure, temperature, and water vapor pressure of the CPTw model is reduced by 14.1%, 25.8%, and 4.8%, compared with that of the GPT2w model. The new model catches especially well the diurnal changes in pressure, temperature, and water vapor pressure, which have never been realized before. Since the CPTw model can provide accurate empirical pressure, temperature, and water vapor pressure for any time and location in China and its surrounding areas, it can not only meet the need of empirical meteorological parameters in real-time geodetic applications like GNSS positioning and navigation, but it is also useful for GNSS meteorology.

Squaring the Circle Between Freedom of Expression and Platform Law

Among the greatest emerging challenges to global efforts to promote and protect human rights is the role of private sector entities in their actualization, since international human rights rules were designed to apply primarily, and in many cases solely, to the actions of governments. This paradigm is particularly evident in the expressive space, where private sector platforms play an enormously influential role in determining the boundaries of acceptable speech online, with none of the traditional guardrails governing how and when speech should be restricted. Many governments now view platform-imposed rules as a neat way of sidestepping legal limits on their own exercise of power, pressuring private sector entities to crack down on content which they would be constitutionally precluded from targeting directly. For their part, the platforms have grown increasingly uncomfortable with the level of responsibility they now wield, and in recent years have sought to modernize and improve their moderation frameworks in line with the growing global pressure they face. At the heart of these discussions are debates around how traditional human rights concepts like freedom of expression might be adapted to the context of “platform law.” This Article presents a preliminary framework for applying foundational freedom of expression standards to the context of private sector platforms, and models how the three-part test, which lies at the core of understandings of freedom of expression as a human right, could be applied to platforms’ moderation functions.

“A marathon, not a sprint”: Canada and South African apartheid, 1987–1990

In 2020, Canada does not maintain diplomatic ties with Iran or Saudi Arabia partly owing to their human rights violations—a choice which has eroded its capacity to act meaningfully in these countries. Thirty years ago, the Brian Mulroney government was faced with a similar decision: to sever relations with the white minority regime in South Africa or use its limited but real influence to contribute constructively to an end to apartheid. This article examines how Canada “punched above its weight” on an issue seemingly peripheral to its national interests from 1987 to 1990. It was during these oft-overlooked years—South Africa’s “darkest days”—that Canada engaged through multilateral fora, bilaterally, and its embassy to sustain global pressure and attention on apartheid. In so doing, the Mulroney government became a diplomatic battleground between its major allies, Pretoria, and its African Commonwealth partners. Such efforts were not without costs, but Canada’s “advanced middling” role helped to bring about a peaceful transition towards majority rule in South Africa and thus holds contemporary lessons for policymakers.

Simulation of lymph flow with consideration of natural gravity force influence

The model of lymph flow in the human lymphatic system in the quasi-one-dimensional approach is considered in the paper. Calculations with natural gravity force influence are presented. Calculations show that in some sets of parameters of lymphatic vessels the physiological flow can be reached in the model with zero global pressure gradient influence only by the “muscle” pump.