A Primer on Pumping and Dumping: How Hedge Funds Do It and How Others Might Profit

Pumping and dumping occurs when the price of a stock is artificially inflated and then drops. Here, we illustrate how hedge funds can accomplish pumping and dumping, and argue why this strategy is likely to be successful for them. We illustrate why writing a short-term in-the-money covered call option might constitute an informed speculation when pumping and dumping is suspected. In contradistinction to the usual practice, estimating the returns of a strategy which is based upon the predictable characteristics of pumping and dumping would be best tested prospectively, and social media communities might fruitfully participate in such research.

A Hybrid Cyber Defense Mechanism to Mitigate the Persistent Scan and Foothold Attack

As the prerequisite for the attacker to invade the target network, Persistent Scan and Foothold Attack (PSFA) is becoming progressively more subtle and complex. Even worse, the static and predictable characteristics of traditional systems provide an asymmetric advantage for attackers in launching the PSFA. To reverse this asymmetric advantage and resist the PSFA, two new defense ideas, called moving target defense (MTD) and deception-based cyber defense (DCD), have been suggested to provide the proactive selectable measures to complement traditional defense. However, MTD is unable to defeat the sophisticated attacker with fingerprint tracking ability. Meanwhile, DCD is easy to be marked by the attacker, which will result in a great waste of defense resources and poor defense effectiveness. To address this shortcoming, we propose the hybrid cyber defense mechanism that combines the address mutation (belonging to MTD) and fingerprint camouflage (belonging to DCD) strategies. More specifically, we first introduce and formalize the attacker model of PSFA based on the cyber kill chain. Afterwards, the traffic direction technology is designed to realize the coordination between the strategy of address mutation and the strategy of fingerprint camouflage. Furthermore, we construct the fine-grained quantitative modeling of the attacker’s behaviors through an in-depth observation of actual network confrontation. Based on this, a dynamic defense strategy generation algorithm is presented to maximize the effectiveness of our hybrid mechanism. Finally, the experimental results show that our hybrid mechanism can greatly improve the time required for a successful attack and achieve a better defense effect than the single strategy.

Tuning Lignin Characteristics by Fractionation: A Versatile Approach Based on Solvent Extraction and Membrane-Assisted Ultrafiltration

Technical lignins, typically obtained from the biorefining of lignocellulosic raw materials, represent a highly abundant natural aromatic feedstock with high potential in a sustainable economy scenario, especially considering the huge primary production volumes and the inherently renewable nature of this resource. One of the main drawbacks in their full exploitation is their high variability and heterogeneity in terms of chemical composition and molecular weight distribution. Within this context, the availability of effective and robust fractionation processes represents a key requirement for the effective valorization of lignin. In the present work, a multistep fractionation of two different well known technical lignins obtained from two distinct delignification processes (soda vs. kraft pulping) was described. A comprehensive approach combining solvent extraction in organic or aqueous medium with membrane-assisted ultrafiltration was developed in order to maximize the process versatility. The obtained lignin fractions were thoroughly characterized in terms of their chemical, physical, thermal, and structural properties, highlighting the ability of the proposed approach to deliver consistent and reproducible fractions of well-controlled and predictable characteristics, irrespective of their biomass origin. The results of this study demonstrate the versatility and the reliability of this integrated multistep fractionation method, which can be easily adapted to different solvent media using the same ultrafiltration membrane set up, thereby enhancing the potential applicability of this approach in an industrial scale-up perspective for a large variety of starting raw lignins.

A theory of self-governance: de facto constitutions as filters

What is self-governance, and under what sets of institutions is it possible? This article explores this question from the perspective of informal (de facto) constitutionalism. The dominant approach, grounded in formal constitutionalism, overlooks crucial institutional features that determine whether governance is something done by individuals to themselves, as opposed to something done by some individuals to others. Understanding self-governance requires not only identifying the durable procedures for public decision-making, but also appreciating how these procedures act as filters that select for the acquisition of political power by individuals with specific and predictable characteristics. The article develops a novel constitutional typology based on the structure of political property rights, on the one hand, and the kinds of individuals that govern, on the other, and use this typology to discover the types of polities most likely to be self-governing.

Impacts of topographic shading on direct solar radiation for valley glaciers in complex topography

Topographic shading, including both shaded relief and cast shadowing, plays a fundamental role in determining direct solar radiation on glacier ice. However, this parameter has been oversimplified or incorrectly incorporated in surface energy balance models in some past studies. Here we develop a topographic solar radiation model to examine the variability in irradiance throughout the glacier melt season due to topographic shading and combined slope and aspect. We apply the model to multiple glaciers in High Mountain Asia (HMA), and test the sensitivity of shading to valley-aspect and latitude. Our results show that topographic shading significantly alters the potential direct clear-sky solar radiation received at the surface for valley glaciers in HMA, particularly for north- and south-facing glaciers. Additionally, we find that shading can be extremely impactful in the ablation zone. Cast shadowing is the dominant mechanism in determining total shading for valley glaciers in parts of HMA, especially at lower elevations. Although shading has some predictable characteristics, it is overall extremely variable between glacial valleys. Our results suggest that topographic shading is not only an important factor contributing to surface energy balance, but could also influence glacier response and mass balance estimates throughout HMA.

Conceptual Overlapping Clustering for Effective Selection of Parental Rice Varieties

The process of rice breeding involves producing new rice varieties as a cross of parental rice varieties followed by rigorous testing and examination phase for purity, productivity and resistivity to regional climatic conditions. The selection of appropriate parental seeds to produce new rice variety with more or less predictable characteristics is highly desirable as it reduces expensive experimental evaluation efforts. Authors suggest the applicability of Conceptual Overlapping Clustering Algorithm [7] developed by them for conceptual overlapping clustering to aid proper selection of rice varieties and demonstrated the performance of this algorithm on a real world dataset.