Is I-Voting I-Llegal?

The Voting Rights Act was passed to prevent racial discrimination in all voting booths. Does the existence of a racial digital divide make Internet elections for public office merely a computer geek\u27s pipe dream? Or can i-voting withstand scrutiny under the current state of the law? This i-Brief will consider the current state of the law, and whether disproportionate benefits will be enough to stop this extension of technology dead in its tracks

In Situ Arsenic Speciation using Surface-enhanced Raman Spectroscopy

Arsenic (As) undergoes extensive metabolism in biological systems involving numerous metabolites with varying toxicities. It is important to obtain reliable information on arsenic speciation for understanding toxicity and relevant modes of action. Currently, popular arsenic speciation techniques, such as chromatographic/electrophoretic separation following extraction of biological samples, may induce the alternation of arsenic species during sample preparation. The present study was aimed to develop novel arsenic speciation methods for biological matrices using surface-enhanced Raman spectroscopy (SERS), which, as a rapid and non-destructive photon scattering technique. The use of silver nanoparticles with different surface coating molecules as SERS substrates permits the measurement of four common arsenicals, including arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV). This speciation was successfully carried out using positively charged nanoparticles, and simultaneous detection of arsenicals was achieved. Secondly, arsenic speciation using coffee ring effect-based separation and SERS detection was explored on a silver nanofilm (AgNF), which was prepared by close packing of silver nanoparticles (AgNPs) on a glass substrate surface. Although arsenic separation using the conventional coffee ring effect is difficult because of the limited migration distance, a halo coffee ring was successfully developed through addition of surfactants, and was shown to be capable of arsenicals separation. The surfactants introduced in the sample solution reduce the surface tension of the droplet and generate strong capillary action. Consequently, solvent in the droplet migrated into the peripheral regions and the solvated arsenicals to migrated varying distances due to their differential affinity to AgNF, resulting in a separation of arsenicals in the peripheral region of the coffee ring. Finaly, a method combining experimental Raman spectra measurements and theoretical Raman spectra simulations was developed and employed to obtain Raman spectra of important and emerging arsenic metabolites. These arsenicals include monomethylarsonous acid (MMAIII), dimethylarsinous acid (DMAIII), dimethylmonothioarinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), S-(Dimethylarsenic) cysteine (DMAIIICys) and dimethylarsinous glutathione (DMAIIIGS). The fingerprint vibrational frequencies obtained here for various arsenicals, some of which have not reported previously, provide valuable information for future SERS detection of arsenicals

Incentive Ratios for Fairly Allocating Indivisible Goods: Simple Mechanisms Prevail

We study the problem of fairly allocating indivisible goods among strategic agents. Amanatidis et al. show that truthfulness is incompatible with any meaningful fairness notions. Thus we adopt the notion of incentive ratio, which is defined as the ratio between the largest possible utility that an agent can gain by manipulation and his utility in honest behavior under a given mechanism. We select four of the most fundamental mechanisms in the literature on discrete fair division, which are Round-Robin, a cut-and-choose mechanism of Plaut and Roughgarden, Maximum-Nash-Welfare and Envy-Graph Procedure, and obtain extensive results regarding the incentive ratios of them and their variants. For Round-Robin, we establish the incentive ratio of $2$ for additive and subadditive cancelable valuations, the unbounded incentive ratio for cancelable valuations, and the incentive ratios of $n$ and $\lceil m / n \rceil$ for submodular and XOS valuations, respectively. Moreover, the incentive ratio is unbounded for a variant that provides the $1/n$-approximate maximum social welfare guarantee. For the algorithm of Plaut and Roughgarden, the incentive ratio is either unbounded or $3$ with lexicographic tie-breaking and is $2$ with welfare maximizing tie-breaking. This separation exhibits the essential role of tie-breaking rules in the design of mechanisms with low incentive ratios. For Maximum-Nash-Welfare, the incentive ratio is unbounded. Furthermore, the unboundedness can be bypassed by restricting agents to have a strictly positive value for each good. For Envy-Graph Procedure, both of the two possible ways of implementation lead to an unbounded incentive ratio. Finally, we complement our results with a proof that the incentive ratio of every mechanism satisfying envy-freeness up to one good is at least $1.074$, and thus is larger than $1$ by a constant

Stochastic Online Metric Matching: Adversarial is no Harder than Stochastic

We study the stochastic online metric matching problem. In this problem, $m$ servers and $n$ requests are located in a metric space, where all servers are available upfront and requests arrive one at a time. In particular, servers are adversarially chosen, and requests are independently drawn from a known distribution. Upon the arrival of a new request, it needs to be immediately and irrevocably matched to a free server, resulting in a cost of their distance. The objective is to minimize the total matching cost. In this paper, we show that the problem can be reduced to a more accessible setting where both servers and requests are drawn from the same distribution by incurring a moderate cost. Combining our reduction with previous techniques, for $[0, 1]^d$ with various choices of distributions, we achieve improved competitive ratios and nearly optimal regrets in both balanced and unbalanced markets. In particular, we give $O(1)$-competitive algorithms for $d \geq 3$ in both balanced and unbalanced markets with smooth distributions. Our algorithms improve on the $O((\log \log \log n)^2)$ competitive ratio of \cite{DBLP:conf/icalp/GuptaGPW19} for balanced markets in various regimes, and provide the first positive results for unbalanced markets

Does Internet use connect smallholder farmers to a healthy diet? Evidence from rural China

IntroductionUndernutrition and micronutrient malnutrition remain problems of significant magnitude among small-scale subsistence farmers, posing a serious threat to their health and well-being. Developing a healthy diet can effectively reduce this threat. Fortunately, the Internet can speed up the process.MethodsBased on survey data from 5,114 farm households in nine provinces in China, this study quantitatively assesses the impact of Internet use on the dietary quality of smallholder farmers using OLS regression models and PSM models.Results/Discussion(1) Internet use can significantly contribute to dietary diversity and dietary rationality among smallholder farmers, thus optimizing their dietary structure. (2) Internet use significantly increased the average consumption amounts of milk and its products (2.9 g), fruits (21.5 g), eggs (7.5 g), and vegetables (27.1 g), while also decreasing the intake of salts (1.5 g) and oil (3.8 g). (3) The pull of internet use to improve diet quality is more significant for smallholder households with lower levels of education, older heads of households, and higher household incomes. (4) A possible mechanism is that Internet use increases household income and information access skills of rural residents, thus improving their dietary quality. In summary, governments should further promote Internet penetration in rural areas for health purposes