Nutritional quality and safety of European perch (Perca fluviatilis) from three lakes of Central Italy

European perch (Perca fluviatilis) harvested from three lakes of Central Italy were studied in different seasonal periods of a year to evaluate their nutritional quality and some safety aspects related to the pollution of the aquatic environment. The lakes considered, located in the Latium region, differed with respect to their volcanic (Bolsena and Bracciano Lakes) or artificial (Salto Lake) origin. Fillets of fish caught in the three lakes were characterised by good protein (17–19%) and mineral contents and low lipid levels (0.6–1.2%) throughout the year. Total lipids were characterised by low cholesterol levels (41.9–74.7 mg/100 g) and high percentages of total n − 3 polyunsaturated fatty acids (27.7–33.8% of total fatty acids), in particular docosahexaenoic acid (14.2–25.3% of total fatty acids). The qualitative analysis of the stomach content of perch confirmed their predatory feeding behaviour. The chemical and nutritional profiles of perch from the three lakes were comparable except for rubidium and cesium levels, which were higher in the muscle tissues of perch from the volcanic lakes. These minerals may represent elements of traceability of the origin of fish. Low levels of organochlorine pesticides and polychlorinated biphenyls, well below the Italian and European action limits, were detected in the muscle tissue of perch from all three lakes.     

A Mathematical Network Model and a Solution Algorithm for IaaS Cloud Computing

Networks and Spatial Economics - Cloud Computing is a type of Internet-based computing, much used in recent years, that relies on sharing computer processing resources and data to computers and...     

Molecular Modeling Studies on the Human Neuropeptide S Receptor and Its Antagonists

Neuropeptide S (NPS) is a 20‐residue peptide of great interest due to its potential involvement in several biological processes such as arousal, anxiety, and food intake. The NPS receptor belongs to the rhodopsin‐like G‐protein‐coupled receptor superfamily, and several polymorphisms and isoforms of this receptor are associated with asthma, allergies, and bronchial hyper‐responsiveness, in particular the Asn 107 Ile mutation. Limited structural information is available for this peptide–receptor system, particularly regarding the NPS receptor structure, its nonpeptide ligands, and the molecular aspects of agonist and antagonist binding processes. In this work, rhodopsin‐based homology models of the NPS receptor and its Asn 107 Ile variant were built and refined in a membrane bilayer model, and binding modes for nonpeptide antagonists were simulated. This study provides the first structural study of the human NPS receptor, and the results provide a starting point for further characterization of the binding modes of its antagonists, and for the rational design of new NPS receptor ligands.     

On the use of TEM cells for the calibration of power frequency electric field meters

This paper focuses on the performances of TEM cells when used in the calibration of power frequency environmental electric field meters. The spatial non-uniformity of the electric field inside a TEM cell is analyzed through experimental investigations and three-dimensional Boundary Element modeling to evaluate the field experienced by the sensing elements of actual 3D meter probes. The perturbation caused by the probe support is also taken into account. The uncertainty component associated with the spatial non-uniformity in the volume taken up by typical power and low frequency field probes is estimated. The field non-uniformity is also evaluated in relation to the use of TEM cells of reduced size. Finally, the field non-uniformity is exploited to predict the performance of an actual field meter operating in significant field gradients.     

Photopolarimeter based on two gratings recorded in thin organic films

A photopolarimeter based on two different kinds of diffraction gratings (a two-grating photopolarimeter) has been developed for real-time measurements of the four elements of the Stokes vector. The main elements of the device are a pure polarization grating and an ordinary transmission grating, both recorded by means of holographic techniques in thin films of organic materials. The first one consists of a diffraction grating recorded by two interfering opposite circularly polarized beams in a Langmuir-Blodgett film of an azo-compound material. The second component is a grating recorded by two interfering parallel circularly polarized beams in a thin film of a photosensitive polymer. Both gratings offer long time stability and good diffraction efficiency. Four photodiodes collect the first-order diffracted beams from these gratings, the output signals of which are read through an analog-to-digital converter by a PC. The optical alignment of the device is easy and the calibration is realized in a one-step procedure.     

In vitro fertilisation with frozen-thawed bovine sperm sexed by flow cytometry and validated for accuracy by real-time PCR

The methodologies used for cytometric sorting of fresh spermatozoa never allowed a clear resolution of sexual chromosomes of frozen-thawed semen. To devise a novel method for the production of bovine predefined sexed embryos using frozen-thawed semen, sorting efficiency of different protocols was studied using a new quantitative real-time PCR method to verify the purity of sexed semen. To this aim, after Percoll separation, frozen-thawed samples were stained at different temperatures and concentrations of Hoechst 33342 using a short-incubation time. The concentration of Hoechst 33342 of 500 mug/ml at a temperature of 37 degrees C provided good and stable fluorescence signals. Preventing the sperm clustering by adding 0.6% BSA in the 90% Percoll fraction led to X-bearing sperms purity of 91+/-2%. Thereafter, sorted sperms were used for in vitro fertilisation (IVF). Despite the lower cleavage rates reported in the sorted groups when compared with the control groups (40 vs 48%, P<0.01), blastocyst formation in the sorted and control groups was not different (27 vs 24% of the cleaved respectively). The PCR analysis of 30 blastocysts confirmed 26 embryos to be correctly sexed (87%). Transfer of two embryos per recipient into six synchronised heifers resulted in four pregnancies. Two abortions occurred at day 60, while two pregnancies went to term delivering two female calves. In conclusion, high purity and repeatability of sorting was obtained with frozen-thawed bull semen that was subsequently used for IVF giving rise to viable embryos and offspring. In addition, real-time PCR revealed to be an optimal support for these studies, providing a rapid and reliable estimation of flow cytometric efficiency.     

HRV scaling exponent identifies postinfarction patients who might benefit from prophylactic treatment with amiodarone

Analysing the Holter recordings collected at baseline during the European Myocardial Infarction Amiodarone Trial (EMIAT), we evaluate the possibility of using alpha, the slope of the power spectrum of heart rate variability signals (HRV) in the vicinity of f = 0, for postinfarction risk stratification. We found no relevant difference in the values of alpha for the placebo population. On the contrary, in the amiodarone arm, the distinction in the survival rates of those with high or low alpha-values was highly significant. Moreover, high risk patients with respect to alpha (higher values) did not seem to benefit from amiodarone. The results suggest that alpha might convey physiologic information that is different than what is expressed by other HRV characteristics, such as the triangular index. When combining high risk patients in term of triangular index (<20) and low risk patients with respect to alpha (相似文献   

Finding the Collineation between Two Projective Reconstructions

The problem of finding the collineation between two 3D projective reconstructions has been proved to be useful for a variety of tasks such as calibration of a stereo rig and 3D affine and/or Euclidean reconstruction. Moreover, such a collineation may well be viewed as a point transfer method between two image pairs with applications to visually guided robot control. Despite this potential, methods for properly estimating such a projective transformation have received little attention in the past. In this paper we describe linear, nonlinear, and robust methods for estimating this transformation. We test the numerical stability of these methods with respect to image noise, to the number of matched points, and as a function of the number of outliers. Finally, we devise a specialized technique for the case where 3D Euclidean coordinates are provided for a number of control points.     

The effectiveness of smoking cessation interventions prior to surgery: a systematic review.

The objective of this review was to evaluate the effectiveness of smoking cessation interventions prior to surgery and examine smoking cessation rates at 6 months follow-up. The Cochrane Library Database, PsycINFO, EMBASE, Medline, and Cinahl databases were searched using the terms: smok$, smoking cessation, tobacco, cigar$, preop$, operati$, surg$, randomi*ed control$ trial, intervention, program$, cessation, abstinen$, quit. Further articles were obtained from reference lists. The search was limited to articles on adults, written in English and published up to December 2006. Only randomized control trials (RCTs) that incorporated smoking cessation interventions to patients awaiting elective surgery were included. Seven studies met the inclusion criteria. Methodological quality was assessed by all the authors. The findings revealed that short-term quit rates (or a reduction by more than half of normal daily rate) ranged from 18% to 93% in patients receiving a smoking intervention (mean 55%), compared with a range of 2%-65% of controls (mean = 27.7%). Two studies examined smoking status at 6 months but these revealed no significant difference in abstinence rates between patients who had received an intervention and those that had not. Studies that incorporated counseling in addition to nicotine replacement therapy appeared to show greater benefits. It is concluded that smoking cessation interventions prior to surgery are effective in helping patients to quit smoking. However, such effects appear to be short-lived. Future research needs to examine intervention and patient factors to see whether tailoring the smoking cessation intervention specifically to the patient improves overall abstinence rates.