Chemical and isotope characterization of lead finds at the Santa Barbara nuraghe (Bauladu, Sardinia)

Twenty lead finds, unearthed in Late Bronze–Early Iron Age levels at the Santa Barbara nuraghe situated at Bauladu in Sardinia (Italy), have been examined. Their chemical composition has been determined using the ICP-MS plasma-mass technique (Cu, Fe, As, Ag, Sn, Sb, Bi, Zn, Cs, Tl, Mo, Cd, In, Te, W, Th, U, Li, Se). Lead isotope ratios (208/206, 207/206, 206/204) have also been determined. The results are discussed in relation to the mineral source and some aspects of the metal extraction processes. The finds are composed of high purity lead obtained using a smelting at low temperature. Based on the isotope ratios it has been possible to establish that the metal originated from Sardinian ore deposits type.     

How to use ISDN Video‐Conferencing to Develop Efficient Remote Education and Corporate Training

Abstract

Integrated Services Digital Network (ISDN) is available today in Macau and has been since 1997. It is emerging as a mainstream telecommunications network that will serve a wide variety of users’ needs. It has improved service capabilities, reduced costs and improved productivity for Macau organizations, both large and small. The following are short notes on possible uses.     

School Students’ Conceptions about Biodiversity Loss: Definitions, Reasons, Results and Solutions

Environmental degradation stemming from anthropocentric causes threatens the biodiversity more than ever before, leading scholars to warn governments about the impending consequences of biodiversity loss (BL). At this point, it is of great importance to study the public’s conceptions of BL in order to identify significant educational implications. However, a review of the literature reveals a relatively small body of research about the public understanding of BL. In this qualitative study, we thus strived to elicit Turkish school students’ conceptions about BL using a written questionnaire including open-ended questions with respect to the definition of biodiversity as well as reasons for, results of and solutions to BL. The sample consisted of 245 school students in a relatively small city. A two-staged content analysis was run on the responses. The results showed that school students most commonly preferred species-focused definitions of biodiversity and understood BL through such various conceptual patterns as, ‘balance of nature’, ‘forest’, ‘global warming’, ‘hunting’ and ‘indirect conservation’. At the end of the paper, the possible educational implications and future perspectives were discussed.     

Preservice Science Teachers’ Efficacy Regarding a Socioscientific Issue: A Belief System Approach

The aim of the present study was to understand the nature of teaching efficacy beliefs related to a socioscientific issue (SSI). We investigated Turkish preservice science teachers’ teaching efficacy beliefs about genetically modified (GM) foods using a belief system approach. We assumed that preservice teachers’ beliefs about GM foods (content knowledge, risk perceptions, moral beliefs, and religious beliefs) and their teaching efficacy beliefs about this topic constitute a belief system, and these beliefs are interrelated due to core educational beliefs. We used an exploratory mixed design to test this model. We developed and administered specific questionnaires to probe the belief system model. The sample for the quantitative part of this study included 441 preservice science teachers from eight universities. We randomly selected eight participants in this group for follow-up interviews. The results showed that preservice science teachers held moderately high teaching efficacy beliefs. Learning and teaching experiences, communication skills, vicarious experiences, emotional states, and interest in the topic were sources of this efficacy. In addition, content knowledge and risk perceptions were predictors of teaching efficacy. We believe that epistemologies based on traditional teaching and the values attached to science teaching are the core beliefs that affect the relationship between predictor variables and teaching efficacy.     

Students and school characteristics related to elementary school students' views of the nature of science

The purpose of this study is to investigate student- and school-level factors that help to explain the difference in the nature of science (NOS) views. Overall, the design of this study is correlational. The sample consisted of 3062 students enrolled in the sixth, seventh, and eighth grades of elementary schools in Turkey. A hierarchical linear modelling was selected as a modelling technique. This study has established the importance of the student's socioeconomic background, learning approaches undertaken, self-efficacy, and motivational goals in the formation of their NOS views. The findings reveal that quality of both the physical infrastructure of schools and the educational resources in schools, parent educational levels, student achievement, self-efficacy, experience of meaningful learning, and learning goal orientation are positively related to different dimensions of student NOS views. Additionally, performance goal orientation and rote learning approaches have a negative relationship with different dimensions of student NOS views.     

The pursuit of excellence or the search for intimacy? The forced‐choice dilemma of gifted youth

Educators often fail to recognize that the intellectually gifted differ from their age peers in their social and emotional development as much as in their intellectual and academic characteristics. A dilemma peculiar to gifted youth arises through the interaction of the psychosocial drives towards intimacy and achievement, which complement each other in students of average ability, but which place the gifted student in a forced‐choice situation. If the gifted child chooses to satisfy the drive for excellence he or she must risk forfeiting the attainment of intimacy with age peers; if the choice is intimacy, the gifted may be forced into a pattern of systematic and deliberate underachievement to retain membership in the social group. Homogeneous grouping of gifted students is suggested as a partial solution to this dilemma.     

Unusually high serum CA19.9 in gastric carcinoma: A case report

We describe a case of poorly differentiated adenocarcinoma of stomach, which did not present typical symptoms of gastrointestinal malignancy on first visit. The patient, a 62 year old smoker presented with shortness of breathe and pain in right lumbar region with no history of fever. Bone scans revealed multiple hot spots in skull, sternum, lumbar vertebrae and both iliac crests. A series of tumor markers were ordered which include PSA, CEA, CA19.9, CA 72.4 and AFP. Serum PSA and AFP concentrations were within normal range. Serum CEA and CA 72.4 were raised significantly. Markedly elevated levels of serum CA19.9 were found (>45000 U/ml) in this patient. CT chest and bronchoscopic examination ruled out the possibility of cancer lung. Upper GI tract endoscopy was done to find out lesion in GI tract. An ulcerative lesion was found in lesser curvature of stomach. Histopathological examination of endoscopic biopsy revealed a poorly differentiated adenocarcinoma of stomach. An unusually high serum CA19.9 (>45000U/ml) in case of gastric carcinoma has not been reported earlier.