Observation of the Berezinskii-Kosterlitz-Thouless Transition in a Two-Dimensional Bose Gas via Matter-Wave Interferometry.

We probe local phase fluctuations of trapped two-dimensional Bose gases using matter-wave interferometry. This enables us to measure the phase correlation function, which changes from an algebraic to an exponential decay when the system crosses the Berezinskii-Kosterlitz-Thouless (BKT) transition. We determine the temperature dependence of the BKT exponent η and find the critical value η_{c}=0.17(3) for our trapped system. Furthermore, we measure the local vortex density as a function of the local phase-space density, which shows a scale-invariant behavior across the transition. Our experimental investigation is supported by Monte Carlo simulations and provides a comprehensive understanding of the BKT transition in a trapped system.

Radiodiagnostic method for studying swimbladder inflammation caused by Anguillicola crassus (Nematoda: Dracunculoidea).

The nematode Anguillicola crassus appeared in Europe about 15 yr ago, and has subsequently become recognised as a cause of major pathological lesions in the swimbladder of the European eel Anguilla anguilla. The radiographic method reported in this paper showed be a useful complement to diagnostic methods that have so far been based exclusively on fish dissection. Using this method, the infection of the swimbladder and the severity of its pathological changes can be assessed in a reliable manner without causing damage to the fish. By analysing radiographs of 45 eels from Lake Balaton, 5 stages of swimbladder lesions were distinguished. The method enables the examiner to draw conclusions on the air, worm and exudate content of the swimbladder; however, data on thickening of the swimbladder wall can be obtained only indirectly. The radiograph also provides information on the air and worm content of the pneumatic duct. Results obtained by radiography showed good agreement with dissection findings. Radiographic results are compared with pathological findings obtained from fish dissections separately for each severity grade of infection.

A preliminary study of the ultrasonographic determination of renal size in the guinea pig (Cavia porcellus).

No standard kidney measurements studies are available for guinea pigs and other pet rodents. Because the size of the kidney often is altered due to diffuse parenchymal renal disease, standardized normal values may help in the ultrasonographic detection of renal enlargement or diminution in vivo. We obtained in vivo ultrasonographic renal measurements from 31 clinically healthy guinea pigs. A significant (P < 0.01) positive correlation was found between renal length and calculated volume compared to body weight (r = 0.459 to 0.535). Renal volume data were calculated from a single sagittal ultrasonographic image by using the area-length prolate ellipsoid mathematic model. Renal volume can be calculated from the data of the regression equation, and both linear and calculated volume measurements correlated to body weight.

Ultrasonographic detection of abdominal abscess in two guinea pigs.

Two guinea pigs (Cavia porcellus) with clinical signs of anorexia, weight loss, depression and abdominal enlargement were examined. During ultrasound examination, a fluid-filled anechogenic structure 3-4 cm in diameter, with echogenic spots and a highly echogenic thick wall, was found in the pelvic region in one case and connected to the liver in the other case. An abscess or a cyst was suspected and surgical treatment including laparotomy was performed. By histopathological examination performed after surgery, a liver abscess was diagnosed in one guinea pig and an abscess in the pelvic region in the other animal.

Radiography and ultrasonography in the diagnosis and treatment of abdominal enlargements in five guinea pigs.

Five guinea pigs with palpable abdominal masses were examined by radiography and ultrasonography, and laparotomy was performed. Splenic haematoma, splenic and uterine haemangioma, uterine fibroma and ovarian teratoma were found on histological examination after excision of the relevant organs. Both of the imaging methods allowed localisation of the affected organs, but the inner structure of the masses could only be imaged by ultrasonography. Ultrasonography served as an aid in decision-making with respect to the laparotomy. Surgery was successful in four out of the five cases. Both imaging methods were found to be useful in diagnosis and in determining the choice of treatment in cases of abdominal masses in guinea pigs.

Abdominal ultrasonography in pet guinea pigs.

Ultrasonographic examination of 40 pet guinea pigs was performed in the framework of this study. Preparation of the patient for ultrasonography and the examination procedure are described. Normal ultrasonographic findings of the abdominal organs including the liver, spleen, kidney and urinary bladder are presented and illustrated for the first time in this species. Ultrasonography was found to be a useful investigative tool in the diagnosis of abdominal diseases in guinea pigs. In comparison to other diagnostic methods like physical examination including palpation, haematological examination, radiography and diagnostic laparotomy, ultrasonography offers a rapid, non-invasive and reliable means of diagnosing abdominal diseases in this species.

Diagnostic radiology of pet and wild birds: a review. I. Radiographic techniques and radiographs of healthy birds.

By the radiographic examination of pet and wild birds, veterinary clinicians may relatively easily obtain additional information that can be used routinely in their everyday diagnostic and therapeutic work. The first part of the present review summarizes the basic technical conditions of radiological examinations, analyses the radiographic features of healthy birds, and describes the procedure and radiological indications of contrast radiography.

Diagnostic radiology of pet and wild birds: a review II. Indications of radiological examination and radiographs of pathological lesions.

The second part of the review dealing with the diagnostic radiology of pet and wild birds discusses the indications of radiological examination, the interpretation of radiographs taken of pathological lesions, and the differential diagnosis of such lesions. Radiology has paramount importance in the diagnosis of diseases affecting the skeletal, digestive, respiratory, urogenital and cardiovascular systems. Certain diseases (shortage of grits, ovarian cysts) cannot be recognized without radiography. Other conditions (e.g. Macaw Wasting Disease, renal tumours, egg retention) require this complementary diagnostic method for confirmation of a suspicion based upon the clinical signs. Radiographic examination is also indicated for follow-up of the surgical management of bone fractures and for facilitating the implantation of transponders aimed at individual identification of the birds.

Radiodiagnostic examination of the swimbladder of some fish species.

Radiodiagnostic methods have not been used previously for studying the anatomy and diseases of the swimbladder of freshwater fish species. In this study, the radiographic anatomy of the swimbladder and species-related differences in swimbladder structure were studied on plain radiographs taken of 12 Hungarian fish species of major economic importance. Changes observed by radiography were also studied by conventional parasitological methods. The radiodiagnostic method reported here appears to be a useful complement to diagnostic examinations that have been based merely on dissection so far. It enables evaluation of the pathological lesions in live condition, without causing damage to the fish.

Ultrasonic diagnosis of ovarian cysts in ten guinea pigs.

Ten guinea pigs with an ovarian cyst had clinical signs of anorexia, alopecia, or depression. Ultrasonographic features of the 2- to 3-cm diameter fluid-filled cysts included compartmentalization and connection to the ovary. In two animals, a unilateral cyst was present, and in two others, the cysts were bilateral. Diagnosis of the disease by plain radiography is difficult because of the similar opacity of ovarian cysts, abdominal neoplasms, and trichobezoars.