5,121 research outputs found
On the Expressive Power of Multiple Heads in CHR
Constraint Handling Rules (CHR) is a committed-choice declarative language
which has been originally designed for writing constraint solvers and which is
nowadays a general purpose language. CHR programs consist of multi-headed
guarded rules which allow to rewrite constraints into simpler ones until a
solved form is reached. Many empirical evidences suggest that multiple heads
augment the expressive power of the language, however no formal result in this
direction has been proved, so far.
In the first part of this paper we analyze the Turing completeness of CHR
with respect to the underneath constraint theory. We prove that if the
constraint theory is powerful enough then restricting to single head rules does
not affect the Turing completeness of the language. On the other hand,
differently from the case of the multi-headed language, the single head CHR
language is not Turing powerful when the underlying signature (for the
constraint theory) does not contain function symbols.
In the second part we prove that, no matter which constraint theory is
considered, under some reasonable assumptions it is not possible to encode the
CHR language (with multi-headed rules) into a single headed language while
preserving the semantics of the programs. We also show that, under some
stronger assumptions, considering an increasing number of atoms in the head of
a rule augments the expressive power of the language.
These results provide a formal proof for the claim that multiple heads
augment the expressive power of the CHR language.Comment: v.6 Minor changes, new formulation of definitions, changed some
details in the proof
“Europe” in Literary Sources: A Political Ideal, and a Strategy
In response to the growth of scholarly interest and research in the field, the present contribution tracks the work done by eminent cultural historians, like Federico Chabod (1962), in the course of the Twentieth century on the occurrences of the word “Europe” in past literary sources, starting with the Middle Ages. On the basis of a trans-historical perspective, the contribution shall draw conclusions on the historical reception of “the birth of Europe” – both as a “Corps Politique”, and as a strategic concept. It is possible to extent this conceptual frame to the development of a European culture, in order to see how this idea, borne out of Medieval epics, might had contributed in good order to shape a European identity, and had exercised at the same time its “agency” under a political and military strategy, to be seen as a counterpart to the more universal idea of a “Christendom”. The phenomenon here discussed is especially rooted in the birth of vernacular cultures and languages, and the discussion throughout the paper will contextually match the reading of European history made up to present times with the analysis of Early romances and novels. In doing so, a critical approach is pursued.info:eu-repo/semantics/publishedVersio
POLIFENOLI DA SEMI DI UVA: NUOVE MOLECOLE PER L'INDUSTRIA NUTRACEUTICA
The reuse of waste products from industrial processes offers the possibility of decreasing waste and having new molecules for the nutraceutical industry. In our work we examined the anti-cancer potential of grape seeds and the antioxidant capacity of an extract of Ginkgo biloba leaves
Polysaccharide-based self-assembling nanohydrogels: An overview on 25-years research on pullulan
The aim of this overview is to review the evolution of the studies carried out, during more than 25 years,
on nanohydrogels obtained by self-assembling of pullulan (PUL) using several hydrophobization strategies.
After the first publications, mainly devoted to the preparation and characterization of PUL
nanogels, a remarkable number of studies demonstrated how wide can be the field of applications within
the main topic of biopharmaceutics. Numerous hydrophilic and lipophilic drugs were entrapped in the
nanogel networks, consequently PUL nanogels have been proposed as delivery systems for single drugs
and for combination therapies which allowed improvements of pharmacological activities and patient
compliance. Furthermore, the large amount of water content allowed loading also proteins which could
maintain their native structure and properties. Stimuli-sensitive and stealth PUL nanogel formulations
allowed improving the performances of antitumor drugs. These nanohydrogels have also been studied
for imaging techniques and for vaccines to be administered by injection and by mucosal application. The
studies on PUL nanogels are still in progress and the perspectives for future researches are also
addressed
Women and Petty Violence in Cheltenham and Exeter, 1880-1909
The historiography of female violence has largely centred on women’s experiences as victims or on their perpetration of lethal acts such as murder and infanticide. In the last decade, however, scholars have paid increasing attention to women’s perpetration of non-lethal violent crime. This thesis contributes to recent scholarship by examining female acts of assault in late Victorian and Edwardian England in an understudied region of the country: whilst most historians have focused on the North, South East or Midlands, this study draws attention to the South West of the country and situates women’s acts of minor violence within the context of wider national patterns. Focusing specifically on cases prosecuted at the Exeter and Cheltenham magistrates’ courts in the years 1880-1909, the thesis follows women through different stages of their offending trajectories: the perpetration of their acts; their treatment by magistrates; their portrayal in the media; and, finally, their experiences after facing prosecution.Using evidence from court records, newspapers and census returns, the study employs both quantitative and qualitative analyses in order to examine patterns in the perpetration and outcome of female non-lethal violence. These examinations reveal that women’s ‘expected’ and ‘actual’ roles – especially those relating to motherhood, wifehood and the neighbourhood – impacted not only the ways in which their assaults were committed but also on their treatment by the justice system and the media. It is also demonstrated that women’s positions could contribute to their propensity to reoffend, an action which sometimes resulted in women’s marginalisation in post-offending life. By following the women’s experiences from the onset to aftermath of their violence, this thesis offers an original and comprehensive contribution to the historiography of female violence in late Victorian and Edwardian England
Use of faeces as an alternative inoculum to caecal content to study in vitro feed digestibility in domesticated ostriches (Struthio camelus var. domesticus)
In order to find an alternative source of inoculum to caecal content for studying the
in vitro feed digestibility in domesticated ostriches (Struthio camelus var. domesticus), caecal content and
faeces of 4 male birds were used as inocula for an in vitro gas production trial.
2. About 1 g of each of 5 substrates (maize silage, CS; alfalfa hay, AH; barley, BG; soybean meal, SM;
beet pulp, BP) was weighed, in quadruplicate per inoculum, in 120 ml flasks; 75 ml of anaerobic medium
and 4ml of reducing solution were added and flasks were kept at 39C. Caecal content and faeces were
diluted respectively 1 : 2 (CI) and 1 : 4 (FI) with an anaerobic medium and were injected into the
respective flasks (10 ml).
3. Gas production was recorded 22 times up to 120 h of incubation and fermentation characteristics
(for instance, degraded organic matter, OMd; potential gas production, A; maximum fermentation rate,
Rmax; time at which it is reached, Tmax; pH; volatile fatty acid, VFA; ammonia) were studied for each
inoculum and substrate.
4. CI and FI showed significant differences in Tmax (1637 vs 1847 h, respectively), propionic (1647 vs
1207 mmoles/l) and butyric acid (650 vs 798 mmoles/l) and ammonia concentration (1718
vs 1995 mmoles/l). The substrates, according to their chemical composition, showed different
fermentation characteristics. However, the regression equations able to estimate some fermentation
characteristics of the caecum from those of faeces were statistically significant and showed R2-values
ranging from 087 to 099.
5. The differences in fermentation pathways of the two inocula did not appear to influence the rate
and extent of OM digestion. Faecal fermentation predicted rates and extent of OM digestion by caecal
fermentation in ostriches; consequently, the faeces could be considered as an alternative to caecal
content to study feed digestibility in the species, although there is a need to undertake further research.
INTRODUCTION
To obtain a useful feed value, it is necessary to
determine digestibility specifically for ostriches,
where the nutritive value of feeds used for diet
formulation is very often erroneously determined
using poultry. The ostrich caecum provides
a suitable environment for the
fermentation of dietary fibre.
Feed digestibility of ostriches in vivo has
been determine
A CFD-based virtual test-rig for rotating heat exchangers
Rotating heat exchangers are used in steel industry, air conditioning and thermal power plants to pre-heat air used in steam generators or for waste heat recovery. Here we focus on a rotating heat exchanger on a so-called Ljungström arrangement operated in thermal power plants to pre-heat the air fed to the steam generators. In these devices the heat exchange between two fluids is achieved through a rotating matrix that gets in contact alternatively with the two fluid streams and acts as a thermal accumulator. To increase the heat capacity and the overall exchange surface, the rotating matrix is filled by a series of folded metal sheets. In the paper we de-scribe a methodology to account for the effects of the Ljungström in a virtual test-rig implemented in a Computational Fluid Dynamics environment. To this aim, a numerical model based on the work of Molinari and Cantiano was derived and implemented in the OpenFOAM library. RANS numerical results were compared with those of a mono-dimensional tool used by ENEL to design Ljungström heat exchangers and validated against available measurements in a real configuration of a thermal power plant
Pushing the edge of dermoscopy in new directions: Entomodermoscopy of Trombicula autumnalis
Dermatologists are often faced with the challenge of patients presenting with non specific symptoms such as itching and or erythema. These symptoms may be attributed to a number of diseases, many of which are trivial, and others even life-threatening. In order to establish the correct diagnosis, dermatologists must rely on good diagnostic tools and knowledge. Dermoscopy was introduced mainly for inspection of pigmented lesions, but its use has now also spread to non-melanoma skin cancer, inflammatory diseases, and almost any skin disease. This diagnostic technique also applies to skin infestation today, often offering the opportunity to rapidly identify new hidden features of parasites. This case report describes an unusual but representative case in which entomodermoscopy enabled a rapid diagnosis in a patient with a non specific erythematous patch. Whereas differential diagnosis of such skin manifestations could have been too laborious and misleading, dermoscopy easily allowed us to find a small parasite, later identified as Trombicula autumnalis
Improvement of obesity-linked skeletal muscle insulin resistance by strength and endurance training.
Obesity-linked insulin resistance is mainly due to fatty acid overload in non-adipose tissues, particularly skeletal muscle and liver, where it results in high production of reactive oxygen species and mitochondrial dysfunction. Accumulating evidence indicates that resistance and endurance training alone and in combination can counteract the harmful effects of obesity increasing insulin sensitivity, thus preventing diabetes. This review focuses the mechanisms underlying the exercise role in opposing skeletal muscle insulin resistance-linked metabolic dysfunction. It is apparent that exercise acts through two mechanisms: (1) it stimulates glucose transport by activating an insulin-independent pathway and (2) it protects against mitochondrial dysfunction-induced insulin resistance by increasing muscle antioxidant defenses and mitochondrial biogenesis. However, antioxidant supplementation combined with endurance training increases glucose transport in insulin-resistant skeletal muscle in an additive fashion only when antioxidants that are able to increase the expression of antioxidant enzymes and/or the activity of components of the insulin signaling pathway are used
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