Atomic secrets and governmental lies : nuclear science, politics and security in the Pontecorvo case

This paper focuses on the defection of nuclear physicist Bruno Pontecorvo from Britain to the USSR in 1950 in an attempt to understand how government and intelligence services assess threats deriving from the unwanted spread of secret scientific information. It questions whether contingent agendas play a role in these assessments, as new evidence suggests that this is exactly what happened in the Pontecorvo case. British diplomatic personnel involved in negotiations with their US counterparts considered playing down the case. Meanwhile, the press decided to play it up, claiming that Pontecorvo was an atom spy. Finally, the British secret services had evidence showing that this was a fabrication, but they did not disclose it. If all these manipulations served various purposes, then they certainly were not aimed at assessing if there was a threat and what this threat really was

Wythoff Wisdom

International audienceSix authors tell their stories from their encounters with the famous combinatorial game Wythoff Nim and its sequences, including a short survey on exactly covering systems

Exploring challenges of visitor- generated waste in Lofotodden National Park

Norway has many scenic and pristine national parks which are desired destinations for foreign and domestic tourists. More visits are encouraged into the parks as they bring local value creation, prompting management to seek enhanced visitor experiences. Recreational activity in vulnerable areas creates pressure and disturbance on ecological values, wildlife, and can detract the experiences in over-visited areas. My thesis explored the challenges of visitor-generated waste in Lofotodden National Park, related to the popular hiking and camping destination of Kvalvika beach. The main objective was to: Explore the challenges of visitor-generated waste in Lofotodden National park in order to create an understanding of the scope of the problem as seen from the tourists’ perspective, investigate visitor-waste relationships and provide initial guidelines for possible management measures. To answer the objective, the study applied an exploratory, mixed method approach using quantitative date from a field waste survey to monitor and map out key locations visitors dispose their waste, and “hot spots” where waste accumulates over the main tourist season, combined with observations of waste distribution and visitors’ behaviors and 26 qualitative semi structured in-depth interviews with visitors. Ajzen’s (1991) “theory of planned behavior” was used as a guiding theory, for identifying some of the prominent attitudes, subjective norms and the perceived behavior control visitors hold towards human waste behavior and management at the specific case area Kvalvika, within Lofotodden National Park. The findings from the three different methods identify and assess different aspects of the littering problem at Kvalvika. The fieldwork documents that littering is visible, accumulating, and dispersed over a gradually larger area during the main tourist season. Littering takes place near informal campsites, and the most common finding is human feces and toilet paper. Observations show that visitors camp close to surface-disposed human feces and use water sources prone to unwanted bacteria without treatment for a variety of personally hygienic activities, such as filling water bottles and brushing teeth. This raises concerns about visitors' health and degradation/wear of protected nature values. The interviews on the other hand find visitors do not perceive a particular waste problem at Kvalvika and experience it as a clean area. They have clearly negative attitudes towards littering. At the same time, the informants do not perceive toilet waste directly as litter, even though toilet paper was often encountered. Very few mentioned littering as problematic for humans, wildlife, or other ecological values, instead the problem was mainly related to aesthetic conditions, according to visitors. Visitors see it as a social norm not to litter and ask for simple management measures, if any. In particular, they support increased information, encouragement to bring "all" waste out, and guidelines for going to the bathroom in nature and to be more considerate of others. However, they do not want to be blamed for littering, which is seen as lazy or uneducated behaviors of others. They are negative or hesitant about "hard" management measures. The tourists see themselves as having the primary responsibility for keeping nature clean. Management can address the waste challenges with various measures, from indirect encouraging and persuasive messaging of wanted behavior from visitors to more direct regulation of access or larger physical measures such as toilets on the beach. Studies on the effect of different waste measures are minimal and adaptive approaches is recommended. Further research is needed to limit man-made waste in national parks and understand the impact of waste on ecological and social values. This study helps to identify areas that are important for further research, that will provide a better basis for effective management measures against littering in the future.Norge har mange nasjonalparker som med sin ville og vakre natur utgjør attraktive reisemål for turister fra inn- og utland. Det oppmuntres til flere besøk i parkene ettersom de frembringer lokal verdiskaping og forvaltningsmyndighetene ønsker kunne legge tilrettelegge for å gi gode opplevelser for besøkende som ikke går ut over verneverdiene. Fritidsaktivitet i sårbare områder skaper press og forstyrrelser på økologiske verdier, dyreliv, og kan forringe opplevelsene i overbesøkte områder. Oppgaven min utforsker utfordringene med besøksgenerert avfall i Lofotodden nasjonalpark knyttet til det populære tur- og campingmålet Kvalvika. Hovedmålet er å: Utforske utfordringene med besøksgenerert avfall i Lofotodden nasjonalpark for å skape empiri om omfanget av problemet/utfordringer sett fra turistens perspektiv. Videre undersøke sammenhenger mellom besøk-avfall-forhold og gi foreløpige anbefalinger om mulig forvaltningsmessige tiltak.M-REI

ISSUES IN A FOOD POLICY

Agricultural and Food Policy,

The rise and fall of the fast breeder reactor technology in the UK: between engineering “dreams” and economic “realities”?

This report explores the evolution of the fast breeder nuclear reactor programmes in the UK, from the period of great promises and expectations in the 1950s and 1960s towards their progressive abandonment in the 1980s and 1990s. The project, of which this report is an element, aims thereby to draw lessons relevant for the current “nuclear renaissance” and medium-term planning on the future of nuclear power. Given that the fast breeder programmes were closely interlinked with the general evolution of nuclear power in the UK, this report includes a fairly detailed historical description of this more general ‘nuclear context’. This primarily chronological description of the evolution of the UK fast breeder programmes provides a basis for a comparison between the evolution of the British and French fast breeder reactor programmes. A central question in such a comparison concerns the lateness of the abandonment of the fast breeder programme in France, as compared to most other countries developing this technology. The cross-country comparison will explore the relative influence of the contextual and historical conditions within which the nuclear technologies have evolved in France and the UK on the one hand, and the ‘universal’ factors common to the evolution of socio-technical systems in general on the other. This exploratory research was based on documentary analysis and eleven interviews of experts involved in, or with knowledge of, the UK fast breeder reactor (FBR) programmes

Spartan Daily, January 13, 1948

Volume 36, Issue 60https://scholarworks.sjsu.edu/spartandaily/11020/thumbnail.jp

Space-Efficient DFS and Applications: Simpler, Leaner, Faster

The problem of space-efficient depth-first search (DFS) is reconsidered. A particularly simple and fast algorithm is presented that, on a directed or undirected input graph $G=(V,E)$ with $n$ vertices and $m$ edges, carries out a DFS in $O(n+m)$ time with $n+\sum_{v\in V_{\ge 3}}\lceil{\log_2(d_v-1)}\rceil +O(\log n)\le n+m+O(\log n)$ bits of working memory, where $d_v$ is the (total) degree of $v$, for each $v\in V$, and $V_{\ge 3}=\{v\in V\mid d_v\ge 3\}$. A slightly more complicated variant of the algorithm works in the same time with at most $n+({4/5})m+O(\log n)$ bits. It is also shown that a DFS can be carried out in a graph with $n$ vertices and $m$ edges in $O(n+m\log^*\! n)$ time with $O(n)$ bits or in $O(n+m)$ time with either $O(n\log\log(4+{m/n}))$ bits or, for arbitrary integer $k\ge 1$, $O(n\log^{(k)}\! n)$ bits. These results among them subsume or improve most earlier results on space-efficient DFS. Some of the new time and space bounds are shown to extend to applications of DFS such as the computation of cut vertices, bridges, biconnected components and 2-edge-connected components in undirected graphs