Observation of Rayleigh-Lamb waves generated by the 2022 Hunga-Tonga volcanic eruption with the POLA detectors at Ny-Ålesund.

The eruption of the Hunga-Tonga volcano in the South Pacific Ocean on January 15, 2022, at about 4:15 UTC, generated a violent explosion, which created atmospheric pressure disturbances in the form of Rayleigh-Lamb waves detected all over the globe. Here we discuss the observation of the Hunga-Tonga shock-wave performed at the Ny-Ålesund Research Station on the Spitsbergen island, by the detectors of the PolarquEEEst experiment and their ancillary sensors. Online pressure data as well as the results of dedicated offline analysis are presented and discussed in details. Results include wave arrival times, wave amplitude measurements and wave velocity calculation. We observed five passages of the shock wave with a significance larger than 3 [Formula: see text] and an amplitude up to 1 hPa. The average propagation velocity resulted to be (308 ± 0.6) m/s. Possible effects of the atmospheric pressure variation associated with the shock-wave multiple passages on the cosmic-ray rate at ground level are also investigated. We did not find any significant evidence of this effect.

Minimal model for zero-inertia instabilities in shear-dominated non-Newtonian flows.

The emergence of fluid instabilities in the relevant limit of vanishing fluid inertia (i.e., arbitrarily close to zero Reynolds number) has been investigated for the well-known Kolmogorov flow. The finite-time shear-induced order-disorder transition of the non-Newtonian microstructure and the corresponding viscosity change from lower to higher values are the crucial ingredients for the instabilities to emerge. The finite-time low-to-high viscosity change for increasing shear characterizes the rheopectic fluids. The instability does not emerge in shear-thinning or -thickening fluids where viscosity adjustment to local shear occurs instantaneously. The lack of instabilities arbitrarily close to zero Reynolds number is also observed for thixotropic fluids, in spite of the fact that the viscosity adjustment time to shear is finite as in rheopectic fluids. Renormalized perturbative expansions (multiple-scale expansions), energy-based arguments (on the linearized equations of motion), and numerical results (of suitable eigenvalue problems from the linear stability analysis) are the main tools leading to our conclusions. Our findings may have important consequences in all situations where purely hydrodynamic fluid instabilities or mixing are inhibited due to negligible inertia, as in microfluidic applications. To trigger mixing in these situations, suitable (not necessarily viscoelastic) non-Newtonian fluid solutions appear as a valid answer. Our results open interesting questions and challenges in the field of smart (fluid) materials.

Detection of nodal micrometastases using immunohistochemistry and PCR in melanoma of the arm and trunk.

Sentinel node (SN) mapping and biopsy seems at present the best way to assess the nodal status in cutaneous melanoma without removing the lymphatic chain. The procedure is minimally invasive, safe and low cost, and allows selection of patients who can benefit from elective node dissection. From March 1997 up to July 1999 we examined 112 SNs excised after lymphatic mapping from 95 patients (48 males and 47 females) with stage I cutaneous melanoma affecting the trunk or limbs. Of these, 88 SNs from 74 patients were submitted to polymerase chain reaction (PCR) in order to detect tyrosinase mRNA. A new antibody (anti-tyrosinase, Clone T311, IgG2a type, Lab Vision Corporation) was used to detect nodal micrometastases. The search for micrometastases was histologically positive in 15 SNs and negative in 97. The 88 SNs examined using molecular biology were positive in 40 cases and negative in 48. In 28 only the PCR was positive. The new antibody used to detect micrometastases was shown to be very useful. Cases positive on both conventional histology and PCR were Clark level II or more and were thicker than 0.6 mm. No difference with regard to site or sex was observed. Lymphoedema and hypersensitivity reactions, nor the inability to work, did not occur. Only patients with histologically proven micrometastases underwent elective node dissection. Cases positive only on molecular biology were submitted to close follow-up.

Robotic telepathology for intraoperative remote diagnosis using a still-imaging-based system.

The aim of the present study was to assess whether a telemicroscopy system based on static imaging could provide a remote intraoperative frozen section service. Three pathologists evaluated 70 consecutive frozen section cases (for a total of 210 diagnoses) using a static telemicroscopy system (STeMiSy) and light microscopy (LM). STeMiSy uses a robotic microscope, enabling full remote control by consultant pathologists in a near real-time manner. Clinically important concordance between STeMiSy and LM was 98.6% (95.2% overall concordance), indicating very good agreement. The rates of deferred diagnoses given by STeMiSy and LM were comparable (11.0% and 9.5%, respectively). Compared with the consensus diagnosis, the diagnostic accuracy of STeMiSy and LM was 95.2% and 96.2%. The mean viewing time per slide was 3.6 minutes, and the overall time to make a diagnosis by STeMiSy was 6.2 minutes, conforming to intraoperative practice requirements. Our study demonstrates that a static imaging active telepathology system is comparable to dynamic telepathology systems and can provide a routine frozen section service.

Nuclear fragmentation characterises paraspermiogenesis in Tubifex tubifex (Annelida, Oligochaeta).

It is known that tubificine oligochaetes produce two types of spermatozoa: eusperm, fertilizing sperm with regular haploid DNA content; and parasperm, with a much lower DNA content, protecting and carrying the eusperm. Whereas mature spermatozoa and spermatids of the two lines are easily recognized by their morphology and DNA content, little is known about the first steps of differentiation of the two lines. This subject is addressed here in two ways: we have measured DNA content by a new method based on confocal laser microscopy and found that the total DNA content of parasperm cysts is extremely variable and equal or lower than total DNA content of eusperm cysts. Then we focused on the spermatocytes, and we found that the cells which will form paraspermatids undergo a peculiar kind of nuclear fragmentation which differ greatly from a regular cell division. During fragmentation DNA is distributed unevenly among the spermatids and this gives rise to a great and variable number of parasperm with variable DNA content. Immunocytochemical assays revealed that a proper meiotic spindle is never formed during fragmentation and that actin may play an important role in the chromatin division. Electron micrographs showed that the centrioles undergo a phenomenon of mass reproduction similar to that found in ciliated epithelia which supplies each of the numerous paraspermatids of its basal body. Mol. Reprod. Dev. 59: 442-450, 2001.

Reproducibility of histopathologic diagnosis and classification of non-melanocytic skin cancer: a panel exercise in the framework of the multicenter southern European study HELIOS.

AIMS AND BACKGROUND: The reproducibility of histologic diagnoses, and in particular of the distinction between basal and squamous cell forms, has been evaluated in the framework of a multicenter case-control study (in Italy, France, Spain and Switzerland) aimed to assess the causes of non-melanocytic skin cancers. METHODS: A panel composed of 10 pathologists from the collaborating centers was appointed. A total of 1,774 slides of routine diagnoses were blindly reviewed by a second panelist; discordant diagnoses underwent a third examination. Controversial and interesting cases were discussed during general sessions. RESULTS: The results showed a high degree of concordance (99.5%), with a Cohen's kappa of 0.85 (95% CI, 0.77-0.94) in the assessment of malignancy of lesions. The concordance in the distinction between large morphologic groups, basal cell carcinoma and squamous cell carcinoma was also high (Cohen's kappa = 0.85; 95% CI, 0.82-0.89). The assessment of histologic subtypes, degree of invasion and differentiation showed a lower degree of concordance, presumably as a consequence of a weaker consistency in the relevant classifications. CONCLUSIONS: The reproducibility study has therefore validated the epidemiologic study and in particular allowed to correct some misclassifications that could have lessened the analysis of the case-control study. In general, because of its characteristics (number of pathologists and variety of their origins, the large number of cases examined, blind examination of histologic slides), the conclusions of the study may show a certain degree of generalization, at least with regard to the countries represented. Routine histologic diagnoses of cutaneous carcinoma showed a high degree of reliability with reference to the assessment of malignancy and the distinction between basal and squamous cell carcinoma morphotypes.

[Telemetric intraoperative diagnosis among hospitals in Trentino: first evaluations and optimization of the procedure]. / La diagnosi intraoperatoria telematica tra Ospedali in Trentino: prime valutazioni ed ottimizzazione delle procedure.

Telemetric, intraoperative frozen section diagnosis may be a useful tool for rural hospitals lacking an in-house pathology service. As a part of a Health Ministry Project on Telemedicine in Trentino (northern Italy), we developed a static telemicroscopy system (STeMiSy). This system connects the rural hospital of Cles with the main hospital of Trento. The two hospitals are 40 kilometers apart, and the road connecting the two towns runs across the mountains and has a heavy traffic. Before putting STeMiSy into practice, we tested the software and hardware on the LAN of the regional hospital system, by connecting the pathology services of Trento and Rovereto (20 kilometers apart). This test phase lasted three months and has not revealed major problems in the LAN nor in the robotic microscope, which was always precise and reliable. The quality of the images and the speed of transmission were largely sufficient for intraoperative frozen section diagnosis. Minor details of the histological slides were not always appreciated on the panoramic view. This loss of some details may be due to the quality of the panoramic view, which represents the 'surfing map' to read the cases. Nevertheless, the recognition of these small details was not so relevant as to change the surgical approaches. An audioconference system, utilizing the same transmission channel, not only slightly slowed the transmission but also caused some instability to the system. The audioconference system has therefore been abandoned, and when necessary we used the normal telephone. Macroscopic images of the whole surgical specimen, the surgeon's responsibility for the sampling, good technical quality of the slide, and good training will allow us to perform remote frozen section diagnosis in the absence of the pathologist. We believe that the main, and probably only, difficulty for this approach is not of a technical nature, but reflects the pathologist's resistance to making a remote video diagnosis.

Digital epiluminescence microscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions. A statistical comparison between visual and computer inspection.

Epiluminescence light microscopy (ELM) has been confirmed to be a useful tool for the diagnosis of pigmented skin lesions. The application of digital systems to epiluminescence represents the latest attempt to improve the diagnosis of cutaneous melanoma. The aim of this study was to compare the diagnostic accuracy of one of these systems, the DB-Dermo MIPS, with the accuracy of well-trained dermatologists using the ELM technique in order to establish the real usefulness of this instrument and to verify how much it can help the clinician make a diagnosis in a clinical setting. During a campaign for the early diagnosis of cutaneous melanoma, 311 patients with non-melanocytic lesions, common naevi, dysplastic naevi and melanomas underwent clinical diagnosis using ELM, computerized evaluation with DB-Dermo MIPS and skin biopsy. Sensitivity, specificity, true and negative predictive value were evaluated for epiluminescence and digital epiluminescence. Our study revealed that the inspection of pigmented skin lesions by digital epiluminescence has a better diagnostic accuracy than that of a trained dermatologist using the epiluminescence technique only. In our experience, this computerized system can play an essential role in the detection of early melanomas.

Information dissemination and training: two key issues for consolidating and strengthening the results of health telematic projects.

The concepts expressed in this paper concerns the activities to be developed within HEALTHLINE, a European project under the Telematics Application programme. HEALTHLINE is an umbrella project which takes initiatives and provides links to other international projects on health telematics. The projects involved are NIVEMES and RISE; they represent the starting point from which a common approach will be developed. The experience gained from these projects has highlighted two emerging requirements: information dissemination and training. To fulfil the needs of information, an Internet corner will be set up; it will allow citizens and health professionals to find and exchange information as well as to discuss themes concerning health care. Due to the most advanced technologies recently introduced, the Health care sector has had to modify its traditional ways of working to aid professionals in exploiting new training techniques and Health Care provision methods. HEALTHLINE will focus on training and on the development of the use of new tools and services. Furthermore, the project will exploit the training methodologies based on multimedia technology for developing training-on-the-job modules. The entire system, in its final stage, will consist of a network for co-operating training and information dissemination; European sites in the project will share information, training material and provide education and information on tele-health, medical and health-care issues to health care providers, beneficiaries and the general public.

Image sampling in static telepathology for frozen section diagnosis.

BACKGROUND: A frozen section diagnostic service is often not directly available in small rural or mountain hospitals. In these cases, it could be possible to provide frozen section diagnosis through telepathology systems. Telepathology is based on two main methods: static and dynamic. The former is less expensive, but involves the crucial problem of image sampling. AIMS: To characterise the differences in image sampling for static telepathology when undertaken by pathologists with different experience. METHODS: As a test field, a previously studied telepathology method based on multimedia email was adopted. Using this method, three pathologists with different levels of experience sampled images from 155 routine frozen sections and sent them to a distant pathology institute, where diagnoses were made on digital images. After the telepathology diagnoses, the glass slides of both the frozen sections and the definitive sections were sent to the remote pathologists for review. RESULTS: Four of 155 transmissions were considered inadequate by the remote pathologist. In the remaining 151 cases, the telepathology diagnosis agreed with the gold standard in 146 (96.7%). There was no significant divergence between the three pathologists in their sampling of the images. Each case comprised five images on average, acquired in four minutes. The overall time for transmission was about 19 minutes. CONCLUSIONS: The results suggest that in routine frozen section diagnosis an inexperienced pathologist can sample images sufficiently well to permit remote diagnosis. However, as expected, the internet is too unreliable for such a time dependent task. An improvement in the system would involve integrated real time features, so that there could be interaction between the two pathologists.

Image selection in static telepathology through the Internet.

A telepathology study was carried out to examine the differences occurring when the images were selected by an experienced pathologist, a junior pathologist and a first-year resident. One hundred and fifty-five consecutive frozen-section pathology cases were collected and sent for consultation to a remote experienced pathologist using multimedia email. Local diagnoses (as reported in the files of the Institute, not from the image selector) and remote diagnoses (based on the images) were compared with those performed on paraffin-embedded sections. Acquisition time and number of selected images were recorded for each case and used to compare the different behaviour of the three local pathologists. Of the 155 cases sent by telepathology, four were considered insufficient for a diagnosis by the remote pathologist and thus the diagnosis was postponed. In the remaining 151 cases, the overall diagnostic agreement between remote and definitive diagnosis was 96.7%. The results indicate that in the routine diagnostic work of a frozen-section service, an inexperienced pathologist can select images which are sufficiently informative for a remote diagnosis, in a sufficiently short time.

Morphometric analysis in prognostic evaluation of stage I thick cutaneous melanomas.

OBJECTIVE: To determine if morphometric analysis could be useful in distinguishing between good and adverse prognosis in thick melanomas. STUDY DESIGN: The study group consisted of 30 cutaneous melanomas (CM) (18 superficial spreading, 11 nodular and 1 acral lentiginous) measuring 1.5-14.8 mm in diameter. Area, perimeter, roundness and aspect ratio of 200 nuclei (100 in the superficial areas and 100 in the lower area) were morphometrically studied. After five years of follow-up, 18 patients were alive, and 12 had died of the tumor. The data were evaluated with univariate and multivariate (Cox's proportional hazard model) analysis. RESULTS: Univariate analysis showed that area and perimeter of superficial and deep nuclei were significantly larger in CM patients than in controls (10 acquired intradermal nevi). Regarding the prognostic role of the variables considered, aspect ratio of the deep nuclei (SD only) was significantly associated with prognosis. Otherwise, size factors (area and perimeter) had no prognostic value. CONCLUSION: Morphometric evaluation of nuclear shape factors in the subset of thick CM represents an additional prognostic tool with statistical significance.

Expert pathology consultation through the Internet: melanoma versus benign melanocytic tumours.

Twenty consecutive cases of melanocytic lesions were chosen from the archives of the archives of the institute of Anatomic Pathology at Santa Chiara Hospital, Trento. Representative images were acquired at a spatial resolution of 512 x 512 pixels, saved in IPEG format and delivered to the remote pathologist by multimedia internet electronic mail. Six cases were diagnosed as benign melanocytic lesions by the local pathologist. Of the 20 cases transmitted, each with an average of 5.3 images, the remote pathologist suggested a diagnosis of malignancy in nine cases while 10 cases were thought to be benign. In one case the images were not considered sufficient for diagnosis. Overall, the diagnostic agreement between local and remote pathologist was 79% (kappa = 0.58, P = 0.002). This preliminary study suggest that telepathology by internet electronic mail can be a valuable tool for remote consultation in dematopathology, as well as for other diagnostic fields where expert consultation is necessary.

Diagnosis of cutaneous melanoma: accuracy of a computerized image analysis system (Skin View).

BACKGROUND/AIMS: Early diagnosis is essential for reducing the high mortality of CM (cutaneous melanoma). An expert dermatologist has a diagnostic accuracy of 85% but, in performing mass screening, the problem is to transfer the experience of a specialized centre to peripheral health clinics. Therefore, some computerized analysis systems were made. The aim of this paper is to compare the diagnostic accuracy of one such system, the Skin View System (SVS), to the accuracy of a well trained dermatologist in order to establish the real usefulness of the instrument and to verify how much it can help the diagnostic accuracy of the clinician in a dermatology setting. METHOD: During a campaign for the early diagnosis of CM, 176 patients with small and flat pigmentary lesions underwent clinical diagnosis, computerized analysis with SVS and skin biopsy. For clinical and computerized diagnosis, we evaluated sensitivity, specificity, true and negative predictive value. RESULTS: The statistical evaluation, in our study, reveals that the computerized system has a diagnostic accuracy lower than that of a trained dermatologist. CONCLUSIONS: This computerized system does not help the clinician in the diagnosis of pigmented lesions.

Dermatoscopy: usefulness in the differential diagnosis of cutaneous pigmentary lesions.

Dermatoscopy has been reported to give valid information in the differential diagnosis of cutaneous pigmentary lesions. Using a dermatoscopy Delta 10 Heine optotechnique, we evaluated 220 pigmented lesions during a health campaign for the early diagnosis of cutaneous melanoma and compared clinical and dermatoscopic diagnosis. Histologic diagnosis was carried out after removal of the lesions. Sensitivity, specificity, positive predictive value, negative predictive value and overall agreement were evaluated. In our experience clinical and dermatoscopic diagnosis gave similar results; sensitivity and specificity were slightly better for dermatoscopy than for clinical diagnosis. The agreement between clinical and dermatoscopic diagnosis was better in histologically negative lesions. Dermatoscopy is useful in the diagnosis of pigmentary lesions, but clinical diagnosis by experienced dermatological staff, is unreplaceable, especially during a health campaign for the early diagnosis of cutaneous melanoma.

Microscopical study of trabeculum after laser cyclotrabeculospasis: case report.

Argon Laser trabeculoplasty and Cyclotrabeculospasis are two common procedures in the treatment of open angle glaucoma. Anatomo-clinical correlation to clarify the exact mechanism of Argon Laser therapy is difficult. We recently used Cyclotrabeculospasis 180 degrees on a patient with open angle glaucoma who developed a choroidal Malignant Melanoma. The eye was enucleated. We studied the trabecular meshwork and Schlemm's canal and measured the inter-trabecular spaces and the opening of Schlemm canal with an ocular micrometer. Comparison of the slides relative to the treated and untreated sections in the same eye seem to confirm the hypothesis of direct traction on the trabecular meshwork by the phocoagulating tissues nearby.

Postirradiation sarcoma in a patient treated for testicular seminoma.

A patient with a sarcoma of the left groin at a site where a prior seminoma had been irradiated is presented. Very few postirradiation sarcomas are described in patients treated with radiation therapy for testicular cancers, even if an increased risk of second malignancies has been reported. In contrast with the highly aggressive clinical course of postirradiation sarcomas, an early discovery of the lesion allowed a radical surgical approach with a presumable cure of the patient. A continuous and precise follow-up of patients irradiated for seminoma is suggested.

p53 Protein expression in nevi and melanomas.

p53 Protein immunohistochemical expression is a wide-spread feature of the malignant phenotype; most melanomas are reported as p53 positive, while nevi are reported as p53 negative. We investigate a series of 75 benign nevi and 47 melanomas (40 primary and seven metastatic) to evaluate their pattern of p53 immunoreactivity with a panel of specific antibodies (PAb1801, PAb240, DO7, and CM1) in view of a possible diagnostic role of p53 immunostaining. Our results demonstrate that 15% of nevi show p53 immunoreactive nuclei (usually in less than 1% of the cells) and that 30% of melanomas show p53 immunoreactive nuclei (one case with 20% immunoreactive cells, six cases with 1% to 5% positive cells, and four cases with less than 1% positive nuclei). p53 Positivity was seen also in basal and suprabasal keratinocytes. p53 Positivity in nevi is at variance with literature data supporting that nevi are p53 negative. p53 Positivity in nevi and in epidermis may be related to mechanisms of DNA repair, apoptosis, or to a specific phase of the cell cycle. In our series, p53 expression in melanomas is not as frequent as reported in the literature. Population-based differences or differences in case selection and sample handling may account for the above discrepancies. The demonstration of p53 positivity in benign skin lesions greatly hinders the possibility of a diagnostic use of p53 immunostaining in dermatopathology.