170 research outputs found
Recommended from our members
Teaching and learning in information retrieval
A literature review of pedagogical methods for teaching and learning information retrieval is presented. From the analysis of the literature a taxonomy was built and it is used to structure the paper. Information Retrieval (IR) is presented from different points of view: technical levels, educational goals, teaching and learning methods, assessment and curricula. The review is organized around two levels of abstraction which form a taxonomy that deals with the different aspects of pedagogy as applied to information retrieval. The first level looks at the technical level of delivering information retrieval concepts, and at the educational goals as articulated by the two main subject domains where IR is delivered: computer science (CS) and library and information science (LIS). The second level focuses on pedagogical issues, such as teaching and learning methods, delivery modes (classroom, online or e-learning), use of IR systems for teaching, assessment and feedback, and curricula design. The survey, and its bibliography, provides an overview of the pedagogical research carried out in the field of IR. It also provides a guide for educators on approaches that can be applied to improving the student learning experiences
Risk factors for sudden cardiac death in hypertrophic cardiomyopathy
Aim of this study was the evaluation of six non invasive clinical indices as risk factors for sudden death (SD)in hypertrophic cardiomyopathy (HCM). Previous syncope, family history of SD, non sustained ventricular tachycardia, abnormalblood pressure response during exercise, excessive hypertrophy ≥3 cm and left ventricular outflow tract obstructionwith a peak gradient ≥30 mmHg were evaluated in a cohort of 166 patients(112 males, 51.8 ± 15.6 years), followed up for amedian of 32.4 months (range 1 to 209 months). During follow up 13 patients reached study’s endpoints: SD, cardiac arrest,documented sustained ventricular tachycardia and/or Implantable Cardioverter Defibrillator (ICD)-discharge. Patients havingexperienced syncope or presenting with a Maximum Wall Thickness ≥3cm in echocardiography were more sensitive to SDemergence since they had a 13.07 (95%CI: 4.00-46.95, p < 0.0001) and a 10.07 (95%CI: 2.92-34.79, p = 0.003) greater relativerisk respectively. In our cohort of patients only two of the six ‘recognised’ potential risk factors for SD were found sensitive,a result causing scepticism about the validity of criteria used for ICD implantation in HCM patients for SD prevention
Subaortic and midventricular obstructive hypertrophic cardiomyopathy with extreme segmental hypertrophy
BACKGROUND: Subaortic and midventricular hypertrophic cardiomyopathy in a patient with extreme segmental hypertrophy exceeding the usual maximum wall thickness reported in the literature is a rare phenomenon. CASE PRESENTATION: A 19-year-old man with recently diagnosed hypertrophic cardiomyopathy (HCM) was referred for sudden death risk assessment. The patient had mild exertional dyspnea (New York Heart Association functional class II), but without syncope or chest pain. There was no family history of HCM or sudden death. A two dimensional echocardiogram revealed an asymmetric type of LV hypertrophy; anterior ventricular septum = 49 mm; posterior ventricular septum = 20 mm; anterolateral free wall = 12 mm; and posterior free wall = 6 mm. The patient had 2 types of obstruction; a LV outflow obstruction due to systolic anterior motion of both mitral leaflets (Doppler-estimated 38 mm Hg gradient at rest); and a midventricular obstruction (Doppler-estimated 43 mm Hg gradient), but without apical aneurysm or dyskinesia. The patient had a normal blood pressure response on exercise test and no episodes of non-sustained ventricular tachycardia in 24-h ECG recording. Cardiac MRI showed a gross late enhancement at the hypertrophied septum. Based on the extreme degree of LV hypertrophy and the myocardial hyperenhancement, an implantation of a cardioverter-defibrillator was recommended prophylactically for primary prevention of sudden death. CONCLUSION: Midventricular HCM is an infrequent phenotype, but may be associated with an apical aneurysm and progression to systolic dysfunction (end-stage HCM)
Methods of sputum processing for cell counts, immunocytochemistry and in situ hybridisation.
Since the first attempts to use standardised methods for sampling induced airways sputum, two methods for processing the expectorate have evolved. The first involves selecting all viscid or denser portions from the expectorated sample with the aid of an inverted microscope. This method has been extensively evaluated and reported in detail. The second approach involves processing the entire expectorate, comprising sputum plus variable amounts of saliva. Recent modifications to this method include collecting saliva and sputum separately in order to reduce salivary contamination. Both methods have advantages and disadvantages.
The advantages of using selected sputum are: squamous cell contamination is v5%, making cell counting easier and quicker to perform, the total cell count (TCC) can be expressed per gram of lower airway secretions, and concentrations of chemicals in the fluid phase are unaffected by the confounding influence of saliva, and can be accurately corrected for dilution. The disadvantage is that selection takes a few minutes longer to perform and requires an inverted microscope. The advantage of using the entire expectorate is that the technique is quicker to perform, but there are some disadvantages that require consideration. The expectorate contains a variable mixture of sputum plus saliva which maydilute the sputum and confound its analysis. The reproducibility of cell counts has been reported to be lower if squamous cell contamination represents w20% of all recovered cells. There is conflicting data as to whether or not differential cell counts (DCCs) differ between the two methods. One study reported a higher percentage of eosinophils in sputum processed by the selection method compared to the entire expectorate but this has not been confirmed in other studies. Although, both the selected sputum and the entire expectorate methods have the same ability to distinguish asthmatics or bronchitics from healthy subjects, they are not interchangeable, and, once a technique has been adopted for a given study, it should always be applied
A Novel Combined Term Suggestion Service for Domain-Specific Digital Libraries
Interactive query expansion can assist users during their query formulation
process. We conducted a user study with over 4,000 unique visitors and four
different design approaches for a search term suggestion service. As a basis
for our evaluation we have implemented services which use three different
vocabularies: (1) user search terms, (2) terms from a terminology service and
(3) thesaurus terms. Additionally, we have created a new combined service which
utilizes thesaurus term and terms from a domain-specific search term
re-commender. Our results show that the thesaurus-based method clearly is used
more often compared to the other single-method implementations. We interpret
this as a strong indicator that term suggestion mechanisms should be
domain-specific to be close to the user terminology. Our novel combined
approach which interconnects a thesaurus service with additional statistical
relations out-performed all other implementations. All our observations show
that domain-specific vocabulary can support the user in finding alternative
concepts and formulating queries.Comment: To be published in Proceedings of Theories and Practice in Digital
Libraries (TPDL), 201
Assessment of a rapid liquid-based cytology method for measuring sputum cell counts
Differential sputum cell counting is not widely available despite proven clinical utility in the management of asthma. We compared eosinophil counts obtained using liquid-based cytology (LBC), a routine histopathological processing method, and the current standard method. Eosinophil counts obtained using LBC were a strong predictor of sputum eosinophilia (≥3%) determined by the standard method suggesting LBC could be used in the management of asthma
Transperitoneal laparoscopic right radical nephrectomy for renal cell carcinoma and end-stage renal disease: a case report
Nephron-sparing surgery (partial nephrectomy) results are similar to those of radical nephrectomy for small (<4 cm) renal tumors. However, in patients with end-stage renal disease, radical nephrectomy emerges as a more efficient treatment for localized renal cell cancer. Laparoscopic radical nephrectomy (LRN) increasingly is being performed. The objective of the present study was to present a case of a patient under hemodialysis who was submitted to LRN for a small renal mass and discuss the current issues concerning this approach. It appears that radical nephrectomy should be the standard treatment in dialysis patients even for small tumors. The laparoscopic technique is associated with acceptable cancer-specific survival and recurrence rate along with shorter hospital stay, less postoperative pain and earlier return to normal activities
Kaposi's sarcoma of the hand mimicking squamous cell carcinoma in a woman with no evidence of HIV infection: a case report
<p>Abstract</p> <p>Introduction</p> <p>Kaposi's sarcoma is a vascular neoplasm mainly affecting the skin of the lower extremities. Although it is the most common neoplasm affecting patients with AIDS, sporadic cases in HIV-negative people have been reported. It is a lesion mainly affecting men and its clinical presentation presents a challenge, as it can resemble other benign or malignant skin lesions.</p> <p>Case presentation</p> <p>We report a rare case of Kaposi's sarcoma presenting in a 68-year-old Mediterranean woman with no evidence of HIV infection. The patient had a 6-month history of a slowly progressing pigmented lesion on the dorsum of her left hand. The lesion clinically resembled a squamous cell carcinoma. The patient was treated with a wide excision of the lesion and primary reconstruction with a full thickness skin graft. Histopathological and immunohistochemical analysis of the excised lesion revealed the presence of Kaposi's sarcoma. Serologic investigation for HIV was negative but polymerase chain reaction for human herpes virus type 8 infection was positive. Thorough clinical and imaging investigation of the abdomen and chest were both negative for loci of disease.</p> <p>Conclusion</p> <p>Kaposi's sarcoma, although rare in its sporadic form, should be considered in the differential diagnosis of indeterminate skin lesions, especially those affecting the extremities.</p
- …