587 research outputs found
Who Bears Responsibility for the Provision of Security: The State or You?
When defining the absence of a threat as an economic good, it is necessary to define this good using the standard economic typology: is security a private, public, club or common good? We argue in this Policy Briefing that security provision can display characteristics belonging to any of these types of goods. In recent years, we can observe a change from more publicly oriented security provision to privately provided security. That does not, however, take away the responsibility of the state to provide a basic level of security. In addition to that, it is the responsibility of the state to coordinate internationally to deliver international security.
What was a mortarium used for? Organic residues and cultural change in Iron Age and Roman Britain.
The Romans brought the mortarium to Britain in the first century AD, and there has long been speculation on its actual purpose. Using analysis of the residues trapped in the walls of these ākitchen blendersā and comparing them with Iron Age and Roman cooking pots, the authors show that it wasn't the diet that changed ā just the method of preparing certain products: plants were being ground in the mortarium as well as cooked in the pot. As well as plants, the mortars contained animal fats, including dairy products. The question that remains, however, is why these natural products were being mixed together in mortaria. Were they for food, pharmaceuticals or face creams?</jats:p
Who Bears Responsibility for the Provision of Security: The State or You?
When defining the absence of a threat as an economic good, it is necessary to define this good using the standard economic typology: is security a private, public, club or common good? We argue in this Policy Briefing that security provision can display characteristics belonging to any of these types of goods. In recent years, we can observe a change from more publicly oriented security provision to privately provided security. That does not, however, take away the responsibility of the state to provide a basic level of security. In addition to that, it is the responsibility of the state to coordinate internationally to deliver international security
Ex-ante Economic Impact Assessment of Green manure Technology in Maize Production Systems in Tanzania
In maize-based farming systems, intercropping of maize with green manure have been increasingly been one of the strategies to revive the declining maize production caused by increasing pestsā infestations and low soil fertility. This study analyzed the potential impacts of adoption of green manure technology on yield, cost, and profitability of maize production in the Eastern Zone of Tanzania. To assess the income and costs effects of maize production using green manure, a farm level budget was constructed from primary and secondary sets of data and information using a with-and-without framework of analysis. A partial budget was constructed to determine the incremental benefits from costs of adopting the green manure technology in managing noxious weeds such as Striga. Results showed that the adoption of green manure technology has a high potential to increase marketable yield, reduce costs and increase net profits. The partial budget analysis showed that green manure would give a net incremental benefit of Tsh. 478 654/acre compared to the chemical fertilizers used by farmers. These additional benefits were realized from increased marketable yields and savings from reduced chemical fertilizers and labour costs. Future research should strive to further develop and strategize dissemination channels to reach more of the smallholder population to increase their knowledge base on the alternative values of green manures. Keywords: Green manure, ex-ante impact assessment, investment in technology, partial budgetin
Limitations of Algebraic Approaches to Graph Isomorphism Testing
We investigate the power of graph isomorphism algorithms based on algebraic
reasoning techniques like Gr\"obner basis computation. The idea of these
algorithms is to encode two graphs into a system of equations that are
satisfiable if and only if if the graphs are isomorphic, and then to (try to)
decide satisfiability of the system using, for example, the Gr\"obner basis
algorithm. In some cases this can be done in polynomial time, in particular, if
the equations admit a bounded degree refutation in an algebraic proof systems
such as Nullstellensatz or polynomial calculus. We prove linear lower bounds on
the polynomial calculus degree over all fields of characteristic different from
2 and also linear lower bounds for the degree of Positivstellensatz calculus
derivations.
We compare this approach to recently studied linear and semidefinite
programming approaches to isomorphism testing, which are known to be related to
the combinatorial Weisfeiler-Lehman algorithm. We exactly characterise the
power of the Weisfeiler-Lehman algorithm in terms of an algebraic proof system
that lies between degree-k Nullstellensatz and degree-k polynomial calculus
Dependence Logic with Generalized Quantifiers: Axiomatizations
We prove two completeness results, one for the extension of dependence logic
by a monotone generalized quantifier Q with weak interpretation, weak in the
meaning that the interpretation of Q varies with the structures. The second
result considers the extension of dependence logic where Q is interpreted as
"there exists uncountable many." Both of the axiomatizations are shown to be
sound and complete for FO(Q) consequences.Comment: 17 page
Genomic alterations and diagnosis of renal cancer
The application of molecular profiling has made substantial impact on the classification of urogenital tumors. Therefore, the 2022 World Health Organization incorporated the concept of molecularly defined renal tumor entities into its classification, including succinate dehydrogenase-deficient renal cell carcinoma (RCC), FH-deficient RCC, TFE3-rearranged RCC, TFEB-altered RCC, ALK-rearranged RCC, ELOC-mutated RCC, and renal medullary RCC, which are characterized by SMARCB1-deficiency. This review aims to provide an overview of the most important molecular alterations in renal cancer, with a specific focus on the diagnostic value of characteristic genomic aberrations, their chromosomal localization, and associations with renal tumor subtypes. It may not yet be the time to completely shift to a molecular RCC classification, but undoubtedly, the application of molecular profiling will enhance the accuracy of renal cancer diagnosis, and ultimately guide personalized treatment strategies for patients
Lithologic and Structural Interpretation of Gravity Data, Northeastern Iowa
A gravity survey was conducted over approximately 4600 square km of northeast Iowa. It was undertaken to provide detailed gravity coverage at approximately 1.6 km intervals and to model the source of several significant gravity and magnetic anomalies. 1,460 gravity stations were occupied in the survey area. Bouguer gravity and residual gravity anomaly maps were prepared, the latter using band-pass filter and trend-surface analysis techniques. The residual maps reveal that the large oval Bouguer gravity anomaly centered beneath Decorah can be traced to the southern border of the survey. Profiles crossing this feature were prepared from the Bouguer map and a total intensity magnetic anomaly map. These profiles, combined with drill hole information, support the interpretation of a mafic (troctolite) intrusive extending over 90 km from the northwest corner of Winneshiek County to near the southern boundary of Fayette County. The western portion is dominated by a shallow elastic basin while the eastern portion appears to be dominantly felsic in nature. The gravity interpretation did not provide conclusive evidence for faulting near Decorah although faulting cannot be ruled out
Graphs Identified by Logics with Counting
We classify graphs and, more generally, finite relational structures that are
identified by C2, that is, two-variable first-order logic with counting. Using
this classification, we show that it can be decided in almost linear time
whether a structure is identified by C2. Our classification implies that for
every graph identified by this logic, all vertex-colored versions of it are
also identified. A similar statement is true for finite relational structures.
We provide constructions that solve the inversion problem for finite
structures in linear time. This problem has previously been shown to be
polynomial time solvable by Martin Otto. For graphs, we conclude that every
C2-equivalence class contains a graph whose orbits are exactly the classes of
the C2-partition of its vertex set and which has a single automorphism
witnessing this fact.
For general k, we show that such statements are not true by providing
examples of graphs of size linear in k which are identified by C3 but for which
the orbit partition is strictly finer than the Ck-partition. We also provide
identified graphs which have vertex-colored versions that are not identified by
Ck.Comment: 33 pages, 8 Figure
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