Modeling electricity loads in California: a continuous-time approach

In this paper we address the issue of modeling electricity loads and prices with diffusion processes. More specifically, we study models which belong to the class of generalized Ornstein-Uhlenbeck processes. After comparing properties of simulated paths with those of deseasonalized data from the California power market and performing out-of-sample forecasts we conclude that, despite certain advantages, the analyzed continuous-time processes are not adequate models of electricity load and price dynamics.Comment: To be published in Physica A (2001): Proceedings of the NATO ARW on Application of Physics in Economic Modelling, Prague, Feb. 8-10, 200

Knowing when to stop: Aberrant precision and evidence accumulation in schizophrenia

Predictive coding and active inference formulations of the dysconnection hypothesis suggest that subjects with schizophrenia (SZ) hold unduly precise prior beliefs to compensate for a failure of sensory attenuation. This implies that SZ subjects should both initiate responses prematurely during evidence-accumulation tasks and fail to inhibit their responses at long stop-signal delays. SZ and healthy control subjects were asked to report the timing of billiards-ball collisions and were occasionally required to withhold their responses. SZ subjects showed larger temporal estimation errors, which were associated with premature responses and decreased response inhibition. To account for these effects, we used hierarchical (Bayesian) drift-diffusion models (HDDM) and model selection procedures to adjudicate among four hypotheses. HDDM revealed that the precision of prior beliefs (i.e., starting point) rather than increased sensory precision (i.e., drift rate) drove premature responses and impaired response inhibition in patients with SZ. From the perspective of active inference, we suggest that premature predictions in SZ are responses that, heuristically, are traded off against accuracy to ensure action execution. On the basis of previous work, we suggest that the right insular cortex might mediate this trade-off

Cyanobacteria microflora in a limestone spring (Troniny spring, Central Poland)

The paper reports a study of cyanobacterial diversity in a cold-water limestone limnocrene in Central Poland. Samples were collected from 1998 to 2000 and in June 2012. The morphology, population characteristics and species composition of the cyanobacteria assemblages were investigated, and the frequency of taxa was recorded. The large number of taxa identified (30) reflects the microhabitat heterogeneity of this spring. Some species considered epiphytes grew on limestone rocks. The occurrence of the majority of the most frequent taxa was related to the physicochemical characteristics of the spring, but none of them can be considered obligatory crenobionts characteristic of limestone springs. The studied spring is a unique ecosystem with an interesting cyanobacteria microflora whose occurrence is attributable to the spring’s water chemistry, low temperature and variety of microhabitats

The structural invisibility of outsiders: the role of migrant labour in the meat-processing industry

This article examines the role of migrant workers in meat-processing factories in the UK. Drawing on materials from mixed methods research in a number of case study towns across Wales, we explore the structural and spatial processes that position migrant workers as outsiders. While state policy and immigration controls are often presented as a way of protecting migrant workers from work-based exploitation and ensuring jobs for British workers, our research highlights that the situation ‘on the ground’ is more complex. We argue that ‘self-exploitation’ among the migrant workforce is linked to the strategies of employers and the organisation of work, and that hyper-flexible work patterns have reinforced the spatial and social invisibilities of migrant workers in this sector. While this creates problems for migrant workers, we conclude that it is beneficial to supermarkets looking to supply consumers with the regular supply of cheap food to which they have become accustomed

The operational window of carbon nanotube electrical wires treated with strong acids and oxidants

Conventional metal wires suffer from a significant degradation or complete failure in their electrical performance, when subjected to harsh oxidizing environments, however wires constructed from Carbon Nanotubes (CNTs) have been found to actually improve in their electrical performance when subjected to these environments. These opposing reactions may provide new and interesting applications for CNT wires. Yet, before attempting to move to any real-world harsh environment applications, for the CNT wires, it is essential that this area of their operation be thoroughly examined. To investigate this, CNT wires were treated with multiple combinations of the strongest acids and halogens. The wires were then subjected to conductivity measurements, current carrying capacity tests, as well as Raman, microscopy and thermogravimetric analysis to enable the identification of both the limits of oxidative conductivity boosting and the onset of physical damage to the wires. These experiments have led to two main conclusions. Firstly, that CNT wires may operate effectively in harsh oxidizing environments where metal wires would easily fail and secondly, that the highest conductivity increase of the CNT wires can be achieved through a process of annealing, acetone and HCl purification followed by either H2O2 and HClO4 or Br2 treatment

Everyday cosmopolitanism in representations of Europe among young Romanians in Britain

The paper presents an analysis of everyday cosmopolitanism in constructions of Europe among young Romanian nationals living in Britain. Adopting a social representations approach, cosmopolitanism is understood as a cultural symbolic resource that is part of everyday knowledge. Through a discursively-oriented analysis of focus group data, we explore the ways in which notions of cosmopolitanism intersect with images of Europeanness in the accounts of participants. We show that, for our participants, representations of Europe are anchored in an Orientalist schema of West-vs.-East, whereby the West is seen as epitomising European values of modernity and progress, while the East is seen as backward and traditional. Our findings further show that representations of cosmopolitanism reinforce this East/West dichotomy, within a discourse of ‘Occidental cosmopolitanism’. The paper concludes with a critical discussion of the diverse and complex ideological foundations of these constructions of European cosmopolitanism and their implications

Ocena bezpieczeństwa i efektywność jabłczanu sunitynibu w przerzutowych guzach neuroendokrynnych trzustki (NEN G1/G2) w zależności od liczby i rodzaju wcześniejszych linii terapeutycznych — doniesienie wstępne

Introduction: The objective of this paper was to assess the safety and efficacy of sunitinib malate in patients with well-differentiated metastatic pancreatic neuroendocrine neoplasms (PNENs) who relapsed on standard therapy.Material and methods: Overall, eight patients with well-differentiated pancreatic neuroendocrine tumours/neoplasm (NET/NEN G1/G2, Ki-67 < 20%), who had relapsed on a standard therapy approach, were treated. All had non-resectable, progressive disease. All received therapy using a standard dose of sunitinib malate. Adverse events were evaluated using NCI-CTC AE v. 3.0.Results: Of the eight patients, seven had non-secretor and single secretor tumour (gastrinoma). Partial remission (PR) was noted in three patients (one after a single therapeutic line, two after two lines), five patients had stabilisation (SD) — including three individuals after three lines, one patient after two lines and another after a single line. Haematological adverse events: leukopenia (25%) — occurred in one patient after three lines and in one patient after two lines; anaemia (25%) — in one patient after three lines and in one patient after one therapeutic line. Mucocutaneous lesions were noted in 37.5% of patients after 2–3 lines of treatment. All of them experienced fatigue syndrome irrespective of the number of therapies. The majority of the patients simultaneously received somatostatin analogues, which did not exacerbate the toxicity profile. The median progression-free survival time (PFS) was 11 months.Conclusions: Sunitinib may be considered as a fairly well-tolerated and effective therapeutic option in progressive non-resectable PNEN patients in the second and subsequent lines of treatment, irrespective of the types of treatment previously applied. (Endokrynol Pol 2014; 65 (6): 472–478)Wstęp: Celem pracy była ocena bezpieczeństwa oraz analiza skuteczności jabłczanu sunitynibu u chorych z przerzutowymi wysokozróżnicowanymi guzami neuroendokrynnymi trzustki (PNET) w drugiej i kolejnych liniach leczenia.Materiał i metody: Analizie poddano 8 pacjentów z wysoko zróżnicowanymi guzami neuroendokrynnymi trzustki (NEN G1/G2, Ki-67 < 20%), u których wystąpiła progresja choroby i otrzymali sunitynib. Wszyscy chorzy byli w stadium nieoperacyjnym. Sunitynib był podawany w standardowej dawce. Działania niepożądane oceniono na podstawie kryteriów NCI-CTC AE v. 3.0.Wyniki: Leczono 8 pacjentów; 7 guzów nieaktywnych hormonalnie i 1 o typie gastrinoma. Częściową remisję (PR) uzyskano u 3 chorych (1 po 1 linii terapeutycznej, 2 — po 2 liniach), 5 chorych miało stabilizację (SD) — w tym 3 było po 3 liniach, 1 po 2 liniach i 1 po 1 linii terapeutycznej. Powikłania hematologiczne: leukopenia (25%) — wystąpiły u 1 pacjenta po 3 liniach i u 1 pacjenta po 2 liniach; niedokrwistość (25%) — u 1 pacjenta po 3 liniach i u 1 pacjenta po 1 linii terapeutycznej. U 37,5% chorych wystąpiły zmiany skórno-śluzówkowe po 2–3 liniach leczenia. U 100% chorych obserwowano zespół zmęczenia niezależnie od liczby terapii. Większość chorych jednocześnie otrzymywała SSA, co nie pogorszyło profilu toksyczności. Mediana czasu wolnego od progresji PFS (progression free survival) – wyniosła 11 miesięcy.Wnioski: Sunitynib może być rozważany, jako dość dobrze tolerowana, skuteczna opcja terapeutyczna u chorych z nieresekcyjnymi PNET w drugiej oraz kolejnych liniach leczenia, niezależnie od rodzaju uprzednio zastosowanych metod. (Endokrynol Pol 2014; 65 (6): 472–478