Ecotourism between theory and practice: empirical analysis of the tourism industry of whale watching in H\ufasav\uedk (Iceland)

Whale watching is a dynamic industry and, in particular in a country like Iceland, where tourism is currently playing a leading role in the national economy and where nature \u2013 understood in a broad sense \u2013 represents the main attraction for visitors, whale watching, rapidly grown during the last years, shows an evident potential under an ecotouristic point of view. In recent times, an increasing need for the understanding of interactions between humans (tourists) and wildlife (whales) emerged, highlighting the interest towards environmental conservation, protection and preservation matters and towards the search for activities, and modalities, that could essentially contribute to the sustainability of tourism experiences, such as wildlife tourism ones. It is difficult to argue with the fact that whale watching uses the whale \u201casset\u201d in a non-destructive way, unlike whaling, activity still commercially conducted in Iceland, but at the same time it can\u2019t be considered ecotouristic and sustainable a priori. In fact, several studies point out how tourism has a disturbing effect on wildlife and negatively affects their ecology and short- to long-term behaviours. This article, after a general introduction on the main ecotourism principles, examines the whale watching industry of the \u201cWhale Capital of Iceland\u201d, H\ufasav\uedk, and it mainly focuses on the results and data of two researches conducted in the field \u2013 respectively among whale watchers and among the local whale watching companies. The purpose of this work is to investigate if and how H\ufasav\uedk whale watching is following an environmentally sustainable and ecotouristic path, and to bring into light its strengths and weaknesses as a whale watching destination

Learning logic programs with negation as failure

Normal logic programs are usually shorter and easier to write and understand than definite logic programs. As a consequence, it is worth investigating their learnability, if Inductive Logic Program- ming is to be proposed as an alternative tool for software development and Software Engineering at large. In this paper we present an exten- sion of the ILP system TRACY, called TRACY-not, able to learn normal logic programs. The method is proved to be sound, in the sense that it outputs a program which is complete and consistent w.r.t.the ex- amples, and complete, in the sense that it does find a solution when it exists. Compared to learning systems based on extensionality,TRACY and TRACY not are less dependent on the kind and number of training examples, which is due to the intensional evaluation of the hypothe- ses and, for TRACY-not, to the possibility to have restricted hypothesis spaces through the use of negation

Energetski kronometabolizam u novozelandskog bijelog kunića.

The temporal organization of some physiological parameters in rabbits by evaluating the circatrigintan rhythms of some haematochemical and haematological parameters, and of rectal temperature, in New Zealand white rabbits was studied. For 30 days before the study the animals all followed the same pattern of daily activity with the natural photoperiod for that season, and were fed on hay ad libitum. Subsequently, the same animals followed another pattern of daily activity for a further 30-day period with a natural photoperiod and were fed on commercial pellets. At the end of each experimental period, blood samples were taken and rectal temperature was measured every 5 days for 30 days. Spectrophotometry in UV was used to calculate the concentration in each sample of: glucose, NEFA, triglycerides, total cholesterol, total proteins, uric acid, urea, albumin, creatinine, calcium, phosphorus and magnesium. The following values were measured on samples rendered unclottable: haematocrit, haemoglobin, RBC, MCV, WBC and VES. A periodic statistical model was used to elaborate the data, on average values of the two sets of samples. Intra-group variance was not significant. Glucose, triglycerides, RBC, Hb, PCV and rectal temperature showed a circatrigintan rhythm in both the experimental periods, but with different acrophases; creatinine, magnesium and phosphorus showed periodicity only when the subjects were fed on hay, while total proteins, urea, albumin and calcium were periodic only when they were fed with commercial pellets. The results obtained showed that the type of ration synchronizes the circatrigintan rhythm of some haematochemical and haematological parameters in the rabbit.Istražena je pojavnost određenih fizioloških osobina na osnovi prosudbe mjesečnog ritma nekih biokemijskih i hematoloških pokazatelja i rektalne temperature u novozelandskog bijelog kunića. Trideset dana su životinje bile držane pod jednakim uvjetima trajanja prirodne svjetlosti i hranjene sijenom ad libitum. U drugom tridesetdnevnom razdoblju držane su pod drugim načinom dnevnih aktivnosti s prirodnim trajanjem dnevne svjetlosti te hranjene komercijalnom peletiranom hranom. Na kraju svakog pokusnog razdoblja uzimani su uzorci krvi i mjerena temperatura svakog petog dana u tijeku 30 dana. UV-spektrofotometrijom određena je u svakom uzetom uzorku koncentracija glukoze, NEFA, triglicerida, ukupnog kolesterola, ukupnih bjelančevina, mokraćne kiseline, mokraćevine, albumina, kreatinina, kalcija, fosfora i magnezija. Određivan je hematokrit, hemoglobin, broj eritrocita, leukocita i VES. Podaci su obrađeni periodičkim statističkim modelom na razini prosječnih vrijednosti dvije skupine uzoraka. Varijanca između skupina nije bila značajna. Vrijednosti glukoze, triglicerida, hemoglobina, PVC te broj eritrocita i vrijednost rektalne temperature pokazivale su tridesetdnevni ritam u oba pokusna razdoblja, ali s različitim najvišim fazama. Vrijednosti kreatinina, magnezija i fosfora pokazivale su periodičnost samo kad su životinje bile hranjene sijenom dok su vrijednosti ukupnih bjelančevina, mokraćevine, albumina i kalcija pokazivale periodičnost kad su životinje bile hranjene peletiranom komercijalnom hranom. Dobiveni rezultati su pokazali da vrst obroka usklađuje tridesetdnevni ritam određenih biokemijskih i hematoloških pokazatelja u kunića

The importance of hematocrit for oxygen delivery and hemodynamics

Anemia is common in elderly patients undergoing surgery and in critical patients. A 72-year-old man submitted to a revision of hip replacement implant was diagnosed with tuberculosis, followed by pulmonary fibrosis, pulmonary heart disease and compensatory erythrocytosis. In the postoperative period, he got anemia which improved his clinical status. Anemia reduces viscosity, i.e. one of the components of vascular resistance to laminar (according to the law of Hagen-Poiseuille) and turbulent flows. In conditions of decreased hematocrit, shear thinning occurs more easily and in larger caliber vessels. Hemodiluition reduces both right and left cardiac afterloads, thus provoking an improvement of the blood flow. As the hematocrit decreases, oxygen delivery increases, because the increase in the cardiac output is greater than the decrease in the concentration of hemoglobin. Further studies are needed to confirm this physical model and to establish the variable and degree of the transfusion trigger

Flow resistance law in channels with fully submerged and rigid vegetation

The estimate of flow resistance in vegetated channels is a challenging topic for programming riparian vegetation management, controlling channel conveyance and flooding propensity, for designing soil bioengineering practices. In this paper, measurements collected by Gualtieri et al. (2018), in a flume where rigid cylinders were set in two arrangements (staggered, aligned) at high submergence ratios (ratio between the water depth and the vegetation height greater than 5), were used to study the effect of rigid submerged vegetation on estimating flow resistance. The theoretical flow resistance equation, obtained by integrating the power flow velocity distribution, was first summarized. Then, this flow resistance equation was calibrated and tested by measurements of Gualtieri et al. (2018). In particular, a relationship between the Γ function of the power velocity distribution, the channel slope, the flow Froude number, and the submergence ratio was established by using the available measurements carried out for the two arrangements with different stem concentrations. The calibration of this relationship was carried out by (i) distinguishing measurements corresponding to different vegetation arrangements (staggered, aligned), (ii) joining all available data, and (iii) using only a scale factor representing the effect of vegetation arrangements. For the cases (ii) and (iii), the analysis demonstrated that the theoretical flow resistance equation allows an accurate estimate of the Darcy–Weisbach friction factor, which is characterized by errors that are always less than 5% and less than or equal to 2.5% for 88% of the investigated cases

Molecular characterization of Anaplasma platys strains from dogs in Sicily, Italy

BACKGROUND: The genetic diversity of Anaplasma platys (Rickettsiales: Anaplasmataceae) strains is currently poorly defined. The present study was designed to characterize A. patys strains in dogs from Palermo, Sicily, Italy, using a combination of PCR and sequence analysis of the 16S rDNA, heat shock operon groESL and citrate synthase (gltA) genes. RESULTS: Blood was collected from 344 dogs (111 pet dogs, 122 pound dogs and 111 hunting dogs) during 2003–2005 in the Province of Palermo, Sicily, Italy. The prevalence of A. platys in dogs in Sicily, as demonstrated by PCR and sequence analysis of the 16S rDNA, groESL and gltA genes, was 4%. None of the samples were positive for A. marginale, A. centrale, A. ovis and A. phagocytophilum DNA. Three different gltA genotypes of A. platys were identified in dogs from Sicily. Two of the gltA sequences of Sicilian A. platys strains were different from sequences reported previously. However, one of the gltA, 16S rDNA and groESL sequences were identical to the sequence of A. platys strains from other regions of the world characterized previously. CONCLUSION: At least three different strains of A. platys were identified in dogs from Sicily by PCR and sequence analyses of the 16S rDNA, groESL and gltA genes. The results reported herein suggested that genetic diversity of A. platys strains may be similar to A. ovis, but lower than the diversity reported for A. marginale and A. phagocytophilum. This lower genetic diversity may have resulted from restricted movement of infected hosts compared to A. marginale-infected cattle and/or the limited host range of A. ovis and A. platys as compared with A. phagocytophilum. These results expand our knowledge about A. platys and encourage further research for analysis of the genetic variation of A. platys strains worldwide