Hydropower development and environmental impact assessments in Vietnam: current practice and shortcomings

Hydropower projects play an important role concerning national energy security in Vietnam; however, the boom in hydropower development in the last ten years had caused many negative impacts on the environment, fisheries, and people’s livelihoods at upstream and downstream river basins, revealing certain weaknesses the management of systems, processes and projects. The main objectives of Environmental Impact Assessments (EIAs) are to reduce environmental impact and to be a supporting tool for decision-making processes. However, this study finds that EIAs of small and medium scale hydropower projects in Vietnam did not assess thoroughly the important factors such as water balance changes, deforestation, aquatic production impacts, and cultural impacts on the indigenous population

(Re) Model Minority: A Discussion of the Past and Present

PURPOSE. The purpose of this zine is to look at historical events that have influenced the way Asian American communities cope with injustices in the United States, and how Asian Americans have been treated throughout history and until now. Throughout this zine, we draw connections between the past and the present– some things may have changed, but others still remain the same. KEEP AN EYE OUT FOR... Analysis of Discriminatory Law Before & After Historical Analysis Satire PANDEMIC. With racial tensions towards Asian American high throughout the world because of COVID-19, it has become relevant to learn about the origins of “Yellow Peril” and why people are developing xenophobic behaviors towards Asians. COVERED ASIAN AMERICAN COMMUNITIES... Chinese Filipinos Japanese Korean Vietnamese PREVIEW. Every community had their own unique experiences with discrimination in the United States. America has had a heavy impact on many Asian countries and has reshaped many cultures through colonization. What we want readers to understand about the zine is that everyone’s contributions are reflections of our own understanding, of historical context from the readings, and how they connect to contemporary issues, such as BLM, the model minority myth, assimilation into American society, and COVID-19.https://digital.sandiego.edu/ethn-zines/1007/thumbnail.jp

Smart Contracts Make Bitcoin Mining Pools Vulnerable

Despite their incentive structure flaws, mining pools account for more than 95% of Bitcoin\u27s computation power. This paper introduces an attack against mining pools in which a malicious party pays pool members to withhold their solutions from their pool operator. We show that an adversary with a tiny amount of computing power and capital can execute this attack. Smart contracts enforce the malicious party\u27s payments, and therefore miners need neither trust the attacker\u27s intentions nor his ability to pay. Assuming pool members are rational, an adversary with a single mining ASIC can, in theory, destroy all big mining pools without losing any money (and even make some profit)

SmartPool: Practical Decentralized Pooled Mining

Cryptocurrencies such as Bitcoin and Ethereum are operated by a handful of mining pools. Nearly $95\%$ of Bitcoin\u27s and $80\%$ of Ethereum\u27s mining power resides with less than ten and six mining pools respectively. Although miners benefit from low payout variance in pooled mining, centralized mining pools require members to trust that pool operators will remunerate them fairly. Furthermore, centralized pools pose the risk of transaction censorship from pool operators, and open up possibilities for collusion between pools for perpetrating severe attacks. In this work, we propose SmartPool, a novel protocol design for a decentralized mining pool. Our protocol shows how one can leverage {\em smart contracts}, autonomous blockchain programs, to decentralize cryptocurrency mining. SmartPool gives transaction selection control back to miners while yielding low-variance payouts. SmartPool incurs mining fees lower than centralized mining pools and is designed to scale to a large number of miners. We implemented and deployed a robust SmartPool implementation on the Ethereum and Ethereum Classic networks. To date, our deployed pools have handled a peak hashrate of 30 GHs from Ethereum miners, resulting in $105$ blocks, costing miners a mere $0.6\%$ of block rewards in transaction fees

On-Orbit Results and Lessons Learned from the ASTERIA Space Telescope Mission

The Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA) was deployed from the International Space Station (ISS) on 20 November 2017, beginning a technology demonstration and opportunistic science mission to advance the state of the art in nanosatellite performance for astrophysical observations. The goal of ASTERIA is to achieve arcsecond-level line-of-sight pointing error and highly stable focal plane temperature control. These capabilities enable precision photometry—i.e. the careful measurement of stellar brightness over time—which in turn allows investigation of astrophysical phenomena such as transiting exoplanets. By the end of the 90-day prime mission, ASTERIA had achieved line-of-sight pointing stability of approximately 0.5 arcseconds root mean square (RMS) over 20-minute observations, pointing repeatability of 1 milliarcsecond RMS from one observation to the next, and focal plane temperature stability better than ±0.01 K over 20-minute observations. This paper presents an overview of the ASTERIA flight and ground system, summarizes the pre-delivery test campaign, and discusses the on-orbit performance obtained by the pointing and thermal control subsystems. We also describe the process for planning opportunistic science observations and present lessons learned from development and operations. Having successfully operated for over 200 days as of this writing, ASTERIA is currently in an extended mission to observe nearby bright stars for transiting exoplanets

The hibernating South American marsupial, Dromiciops gliroides, displays torpor-sensitive microRNA expression patterns

When faced with adverse environmental conditions, the marsupial Dromiciops gliroides uses either daily or seasonal torpor to support survival and is the only known hibernating mammal in South America. As the sole living representative of the ancient Order Microbiotheria, this species can provide crucial information about the evolutionary origins and biochemical mechanisms of hibernation. Hibernation is a complex energy-saving strategy that involves changes in gene expression that are elicited in part by microRNAs. To better elucidate the role of microRNAs in orchestrating hypometabolism, a modified stem-loop technique and quantitative PCR were used to characterize the relative expression levels of 85 microRNAs in liver and skeletal muscle of control and torpid D. gliroides. Thirty-nine microRNAs were differentially regulated during torpor; of these, 35 were downregulated in liver and 11 were differentially expressed in skeletal muscle. Bioinformatic analysis predicted that the downregulated liver microRNAs were associated with activation of MAPK, PI3K-Akt and mTOR pathways, suggesting their importance in facilitating marsupial torpor. In skeletal muscle, hibernation-responsive microRNAs were predicted to regulate focal adhesion, ErbB, and mTOR pathways, indicating a promotion of muscle maintenance mechanisms. These tissue-specific responses suggest that microRNAs regulate key molecular pathways that facilitate hibernation, thermoregulation, and prevention of muscle disuse atrophy.Link_to_subscribed_fulltex

Demonstrating high-precision photometry with a CubeSat: ASTERIA observations of 55 Cancri e

ASTERIA (Arcsecond Space Telescope Enabling Research In Astrophysics) is a 6U CubeSat space telescope (10 cm x 20 cm x 30 cm, 10 kg). ASTERIA's primary mission objective was demonstrating two key technologies for reducing systematic noise in photometric observations: high-precision pointing control and high-stabilty thermal control. ASTERIA demonstrated 0.5 arcsecond RMS pointing stability and $\pm$10 milliKelvin thermal control of its camera payload during its primary mission, a significant improvement in pointing and thermal performance compared to other spacecraft in ASTERIA's size and mass class. ASTERIA launched in August 2017 and deployed from the International Space Station (ISS) November 2017. During the prime mission (November 2017 -- February 2018) and the first extended mission that followed (March 2018 - May 2018), ASTERIA conducted opportunistic science observations which included collection of photometric data on 55 Cancri, a nearby exoplanetary system with a super-Earth transiting planet. The 55 Cancri data were reduced using a custom pipeline to correct CMOS detector column-dependent gain variations. A Markov Chain Monte Carlo (MCMC) approach was used to simultaneously detrend the photometry using a simple baseline model and fit a transit model. ASTERIA made a marginal detection of the known transiting exoplanet 55 Cancri e ($\sim2$~\Rearth), measuring a transit depth of $374\pm170$ ppm. This is the first detection of an exoplanet transit by a CubeSat. The successful detection of super-Earth 55 Cancri e demonstrates that small, inexpensive spacecraft can deliver high-precision photometric measurements.Comment: 23 pages, 9 figures. Accepted in A

CRP 463: Active Transportation Plan for the City of Paso Robles

As a part of CRP 463 led by Dr. William Riggs, this report provided an analysis of the bicycle, pedestrian and transit travel in the City of Paso Robles and produced a draft Active Transportation Plan for the City

NuSTAR Hard X-ray Survey of the Galactic Center Region I: Hard X-ray Morphology and Spectroscopy of the Diffuse Emission

We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, extending the detection of their power-law spectra with $\Gamma\sim1.3$-$2.3$ up to ~50 keV. A morphological and spectral study of the filaments suggests that their origin may be heterogeneous, where previous studies suggested a common origin in young pulsar wind nebulae (PWNe). NuSTAR detects non-thermal X-ray continuum emission spatially correlated with the 6.4 keV Fe K$\alpha$ fluorescence line emission associated with two Sgr A molecular clouds: MC1 and the Bridge. Broad-band X-ray spectral analysis with a Monte-Carlo based X-ray reflection model self-consistently determined their intrinsic column density ($\sim10^{23}$ cm$^{-2}$), primary X-ray spectra (power-laws with $\Gamma\sim2$) and set a lower limit of the X-ray luminosity of Sgr A* flare illuminating the Sgr A clouds to $L_X \stackrel{>}{\sim} 10^{38}$ erg s$^{-1}$. Above ~20 keV, hard X-ray emission in the central 10 pc region around Sgr A* consists of the candidate PWN G359.95-0.04 and the CHXE, possibly resulting from an unresolved population of massive CVs with white dwarf masses $M_{\rm WD} \sim 0.9 M_{\odot}$. Spectral energy distribution analysis suggests that G359.95-0.04 is likely the hard X-ray counterpart of the ultra-high gamma-ray source HESS J1745-290, strongly favoring a leptonic origin of the GC TeV emission.Comment: 27 pages. Accepted for publication in the Astrophysical Journa