The development of a sustainable agricultural industry through the application of biochar and pyroligneous acid

This paper marks the first in a series of studies into the potential use of pyrolysis products in the development of more sustainable practices within the agricultural industry. In this study, the immediate benefits of the application of biochar to crop yields of Raphanus sativus (radishes) are assessed. Furthermore, the study reports on the preliminary findings into the potential application of pyroligneous acid (wood vinegar) as a biocidal agent against crop disease. Although germination tests undertaken on biochar/compost blends of up to 1: 2, by weight, showed no significant adverse effect from the addition of the nutrient rich carbonaceous solid, evidence of substantial increases in crop yield through the addition of biochar were not observed. In sharp contrast, zones of inhibition were observed at 3-10 vol. % upon application of pyroligneous acid to two causal agents responsible for certain diseases in vegetable and fruit crops, i.e. Rhizobium radiobacter (agrobacterium tumefaciens) and Xanthomonas campestris, highlighting the versatility in the application of pyrolysis products and avenues for exploration in the development of this biomass conversion technology.

A túl- és az alulképzés bérhozama 25 európai országban (Returns for over-education and under-education for 25 European countries)

A tanulmányban 25 ország, kétezres évek közepi állapotot tükröző, reprezentatív keresztmetszeti mintáin egyrészt a Duncan-Hoffman-féle modellre támaszkodva megvizsgáljuk, hogy adatbázisunk milyen mértékben tükrözi az illeszkedés bérhozamával foglalkozó irodalom legfontosabb empirikus következtetéseit, másrészt - a Hartog- Oosterbeek-szerzőpáros által javasolt statisztikai próbák segítségével - azt elemezzük, hogy a becslések eredményei alapján mit mondhatunk Mincer emberitőke-, valamint Thurow állásversenymodelljének érvényességéről. Heckman szelekciós torzítást kiküszöbölő becslőfüggvényén alapuló eredményeink jórészt megerősítik az irodalomban vázolt legfontosabb empirikus sajátosságokat, ugyanakkor a statisztikai próbák az országok többségére nézve cáfolják mind az emberi tőke, mind az állásverseny modelljének empirikus érvényességét. / === / Using the Duncan–Hoffman model, the paper estimates returns for educational mismatch using comparable micro data for 25 European countries. The aim is to gauge the extent to which the main empirical regularities shown in other papers on the subject are confirmed by this data base. Based on tests proposed by Hartog and Oosterbeek, the author also considers whether the observed empirical patterns accord with the Mincerian basic human-capital model and Thurow's job-competition model. Heckman's sample-selection estimator shows the returns to be fairly consistent with those found in the literature; the job-competition model and the Mincerian human-capital model can be rejected for most countries.

Stochastic bankruptcy games

We study bankruptcy games where the estate and the claims have stochastic values. We use the Weak Sequential Core as the solution concept for such games. We test the stability of a number of well known division rules in this stochastic setting and find that most of them are unstable, except for the Constrained Equal Awards rule, which is the only one belonging to the Weak Sequential Core.

Transferable Utility Games with Uncertainty

We introduce the concept of a TUU-game, a transferable utility game with uncertainty. In a TUU-game there is uncertainty regarding the payoffs of coalitions. One out of a finite number of states of nature materializes and conditional on the state, the players are involved in a particular transferable utility game. We consider the case without ex ante commitment possibilities and propose the Weak Sequential Core as a solution concept. We characterize the Weak Sequential Core and show that it is non-empty if all ex post TUgames are convex.

Transferable Utility Games with Uncertainty

We introduce the concept of a TUU-game, a transferableutilitygame with uncertainty. In a TUU-game there is uncertainty regarding the payoffs of coalitions. One out of a finite number of states of nature materializes and conditional on the state, the players are involved in a particular transferableutilitygame. We consider the case without ex ante commitment possibilities and propose the Weak Sequential Core as a solution concept. We characterize the Weak Sequential Core and show that it is non-empty if all ex post TU-games are convex.

A Note on The Weak Sequential Core of Dynamic TU Games

This paper addresses a problem with an argument in Kranich, Perea, and Peters (2005) supporting their definition of the Weak Sequential Core and their characterization result. We also provide the remedy, a modification of the definition, to rescue the characterization.

Cooperation under incomplete contracting

We examine the notion of the core when cooperation takes place in a setting with time and uncertainty. We do so in a two-period general equilibrium setting with incomplete markets. Market incompleteness implies that players cannot make all possible binding commitments regarding their actions at different date-events. We unify various treatments of dynamic core concepts existing in the literature. This results in definitions of the Classical Core, the Segregated Core, the Two-stage Core, the Strong Sequential Core, and the Weak Sequential Core. Except for the Classical Core, all these concepts can be defined by requiring absence of blocking in period 0 and at any date-event in period 1. The concepts only differ with respect to the notion of blocking in period 0. To evaluate these concepts, we study three market structures in detail: strongly complete markets, incomplete markets in finance economies, and incomplete markets in settings with multiple commodities.

Sztochasztikus csődjátékok - avagy hogyan osszunk szét egy bizonytalan méretű tortát? = Stochastic bankruptcy games. How can a cake of uncertain dimensions be divided?

A kooperatív játékelmélet egyik legjelentősebb eredménye, hogy számos konfliktushelyzetben stabil megoldást nyújt. Ez azonban csak statikus és determinisztikus környezetben alkalmazható jól. Most megmutatjuk a mag egy olyan kiterjesztését - a gyenge szekvenciális magot -, amely képes valós, dinamikus, bizonytalan környezetben is eligazítást nyújtani. A megoldást a csődjátékok példájára alkalmazzuk, és segítségével megvizsgáljuk, hogy a pénzügyi irodalom ismert elosztási szabályai közül melyek vezetnek stabil, fenntartható eredményre. _______ One of the most important achievements of cooperative game theory is to provide a stable solution to numerous conflicts. The solutions it presents, on the other hand, have been limited to situations in a static, deterministic environment. The paper examines how the core can be extended to a more realistic, dynamic and uncertain scenario. The bankruptcy games studied are ones where the value of the estate and of the claims are stochastic, and a Weak Sequential Core is used as the solution concept for them. The author tests the stability of a number of well known division rules in this stochastic setting and finds that most are unstable, except for the Constrained Equal Awards rule, which is the only one belonging to the Weak Sequential Core.

Assignment Games with Externalities

We examine assignment games, wherematched pairs of firms and workers create some monetary value to distribute among themselves and the agents aim to maximize their payoff. In the majority of this literature, externalities - in the sense that a pair’s value depends on the pairing of the others - have been neglected. However, inmost applications a firm’s success depends on, say, the success of its rivals and suppliers. Thus, it is natural to ask how the classical results on assignment games are affected by the introduction of externalities? The answer is – dramatically. We find that (i) a problem may have no stable outcome, (ii) stable outcomes can be inefficient (not maximize total value), (iii) efficient outcomes can be unstable, and (iv) the set of stable outcomes may not form a lattice. We show that stable outcomes always exist if agents are "pessimistic." This is a knife-edge result: there are problems in which the slightest optimism by a single pair erases all stable outcomes.

Domestic and foreign isolationism in an interdependent world

Since Plato's Republic and Aristotle's Politics established the basis for Western political thought almost 2500 years ago, the discipline of international relations has evolved substantially. However, most of the literature revolves around state interaction within the system, and there is little discussion of countries that opt out of the international states system and become isolationist. Given the interdependent nature of the modern international system, this study elaborates on domestic and foreign isolationism by expounding upon the reasons and consequences of states opting out of the international system. The empirical case studies utilized to explore isolationism are Albania, North Korea, and Burma. By empirically verifying the components, motivations, and consequences of isolationism in an interdependent world, this study provides insight into why and how states resist engagement with the global socioeconomic and political state system. ^ Using historical, comparative, and inductive analysis, this study explains why states choose to isolate themselves both domestically and internationally. Specifically, comparative historical analysis highlights isolationism as a concept and practice. This study maintains that extreme forms of self-imposed isolation in an interdependent international system, while perhaps serving the immediate interests of a ruling regime, harms the long-term national interests of the state and the populace. Although the leadership in an isolationist state gains a significant amount of power and control over the people within its borders, the state as a whole experiences profound negative effects. In the long term, a state loses power, stability, prestige, and suffers a decline in overall economic prosperity. ^ States that withdraw from the international system, therefore, provide insight into an unexplored area of international relations when considering notions of rationality, self-interest, power politics, cooperation, and alliances. In short, isolationism in an interdependent state system goes against the logic of the modern society/system of states, resulting in deleterious consequences to the wellbeing of the state. ^

Factors that differentiate persistence beyond the first session at a for-profit university

An increasing number of students are selecting for-profit universities to pursue their education (Snyder, Tan & Hoffman, 2006). Despite this trend, little empirical research attention has focused on these institutions, and the literature that exists has been classified as rudimentary in nature (Tierney & Hentschke, 2007). The purpose of this study was to investigate the factors that differentiated students who persisted beyond the first session at a for-profit university. A mixed methods research design consisting of three strands was utilized. Utilizing the College Student Inventory, student’s self-reported perceptions of what their college experience would be like was collected during strand 1. The second strand of the study utilized a survey design focusing on the beliefs that guided participants’ decisions to attend college. Discriminant analysis was utilized to determine what factors differentiated students who persisted from those who did not. A purposeful sample and semi-structured interview guide was used during the third strand. Data from this strand were analyzed thematically. Students’ self-reported dropout proneness, predicted academic difficulty, attitudes toward educators, sense of financial security, verbal confidence, gender and number of hours worked while enrolled in school differentiated students who persisted in their studies from those who dropped out. Several themes emerged from the interview data collected. Participants noted that financial concerns, how they would balance the demands of college with the demands of their lives, and a lack of knowledge about how colleges operate were barriers to persistence faced by students. College staff and faculty support were reported to be the most significant supports reported by those interviewed. Implications for future research studies and practice are included in this study.

Middle -class immigrant identities: Dominican-Americans in South Florida

Identity studies of immigrants are complex because of multiple influences affecting identity reconstruction during immigration and acculturation: nationality, socio-cultural differences, occupations, education, spatial and geographic locations, age, gender, and personal attributes. Most immigrant identity studies deal with lower-income immigrants, who do not have the resources of middle- and upper-middle-class immigrants. South Florida is “home” to many middle-class immigrants, including Dominican-Americans. This dissertation interviewed sixty-six Dominican immigrants in South Florida, in order to determine their reconstructed identities after immigration/resettlement and to discover what influences contributed to these changes in identities. ^ The research design of this dissertation utilized an inductive, qualitative model, with the “grounded theory” method of data collection, categorization, and analysis. Participants were selected by a snowball sampling and interviewed with an informal questionnaire. Results were transcribed, categorized, tabulated, and analyzed for conclusions and theorization on immigrant identity. ^ The dissertation addressed numerous influences relating to identity reconstruction: the differing circumstances of immigration, the unique resources of middle- and higher-class immigrants, the nurturing environment of South Florida for immigrants with education and professional skills, and the boundary protection offered by suburban spaces. The interviewees displayed a wide range of age, length of residence in the United States, reasons for immigration, entry ports, settlement, relocations, occupations, and claimed identities. Identity was cross-tabulated with the various influences, as a means of invalidating certain influences and indicating possible trends. ^ The dissertation concluded that middle-class immigrant identities are diverse and multiple, as are the related influences. None of these immigrants had become totally assimilated, nor have they retained dual, non-overlapping attachments or frames of reference. Instead, many of the immigrants seemed to have developed or negotiated two or more identities, according to need, context, and personal interest. A cosmopolitan community such as South Florida seems to have encouraged such multiplicity of identity. However, rather than forming free-flowing identities, most of these immigrants eventually developed diverse and hybrid identities that have bounded attachments to various networks, groups, and places in South Florida. ^