1,721,294 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The Role of Genetic factors in Susceptibility to Esophageal Squamous Cell Carcinoma (ESCC)
No full textEsophageal squamous cell carcinoma (ESCC) is a common cancer in the northeast of Iran. In a series of studies we explored the genetic basis for this. First we showed the risk to age 75 of esophageal cancer in the first-degree relatives of patients with esophageal cancer was 34%, versus 14% for the first-degree relatives of the controls (hazard ratio = 2.3, 95%CI = 1.7-3.1; P = 3 x 10 – 8). Second, in a candidate-gene association approach, we showed that the ADH1B p.Arg48His mutation was associated with a significantly decreased risk of ESCC (OR = 0.41, 95%CI = 0.29-0.76; P = 4x10-4) under a recessive mode of inheritance, although our study subjects were not alcohol drinkers. Third, we showed the BRCA2 p.Lys3326X variant to be associated with increased risk of ESCC (OR = 3.38, 95%CI = 1.97-6.91; P = 2x10-4). Then, we hypothesized that the genes for Fanconi anemia may be candidate genes for ESCC and sequenced the entire coding regions of 12 Fanconi anemia genes in the germline DNA of 190 ESCC cases. We identified three heterozygous insertion/deletions in FANCD2, FANCE and FANCL. All three patients had a strong family history of ESCC. In addition, we found two homozygous patients for the deleterious FANCA p.Ser858Arg mutation. We found two more homozygotes in 556 more ESCC patients, but in none of 1373 matched controls (OR = 16.7, 95%CI = 6.2-44.2; P = 0.01). Finally, we implemented a pilot genome-wide association study in ESCC using 182 cases and 177 matched controls. None of the 1.2 M observed and imputed SNPs showed an association with ESCC at a genome-wide significance level. This showed that an ESCC susceptibility allele with OR>3 estimated from our familial risk study, is unlikely to be identified among common variants of the human genome and we should look for it among rare variants.Ph
The Impact of Prophylactic Salpingo-oophorectomy on Health in Women who carry a BRCA1 or BRCA2 Mutation
Get PDFProphylactic salpingo-oophorectomy, the preventive removal of the ovaries and fallopian tubes, is recommended to women who carry a BRCA1 or BRCA2 mutation in order to reduce the risk of breast, ovarian and fallopian tube cancer. The short and long term health and quality of life effects of this procedure are not well understood. We examined the actual and perceived reduction in cancer risk associated with this surgery. The impact of prophylactic salpingo-oophorectomy on health-related quality of life, psychological distress, cancer worry, menopausal symptoms, and sexual function during the year following surgery was also evaluated. In our prospective study, prophylactic salpingo-oophorectomy was associated with an 80% reduction in ovarian and fallopian tube cancer risk. The residual risk for primary peritoneal cancer was 0.2% per year or 4.3% at 20 years after salpingo-oophorectomy. Most women accurately perceived their risk of breast cancer. However, the risk for ovarian cancer was overestimated, particularly by women who carry a BRCA2 mutation. Physical and mental health-related quality of life did not decrease in the year following surgery; and psychological distress was similar to levels experienced by the general population. Most women were significantly less worried about cancer after the surgery, however, a subset of women continued to experience significant cancer specific distress after prophylactic salpingo-oophorectomy. Women who underwent prophylactic salpingo-oophorectomy when premenopausal experienced a significant worsening of vasomotor symptoms and a decline in sexual functioning. Hormone replacement therapy mitigated these symptoms, but not to pre-surgical levels. Dyspareunia was somewhat alleviated by hormone replacement therapy, however, the decrease in sexual pleasure was not. Satisfaction with the decision to undergo prophylactic salpingo-oophorectomy was high regardless of these symptoms. These studies will provide women who are considering prophylactic salpingo-oophorectomy with information about the reduction in cancer risk associated with the surgery and the possible effects experienced during the year following surgery.Ph
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The Role of Genetic factors in Susceptibility to Esophageal Squamous Cell Carcinoma (ESCC)
Get PDFEsophageal squamous cell carcinoma (ESCC) is a common cancer in the northeast of Iran. In a series of studies we explored the genetic basis for this. First we showed the risk to age 75 of esophageal cancer in the first-degree relatives of patients with esophageal cancer was 34%, versus 14% for the first-degree relatives of the controls (hazard ratio = 2.3, 95%CI = 1.7-3.1; P = 3 x 10 – 8). Second, in a candidate-gene association approach, we showed that the ADH1B p.Arg48His mutation was associated with a significantly decreased risk of ESCC (OR = 0.41, 95%CI = 0.29-0.76; P = 4x10-4) under a recessive mode of inheritance, although our study subjects were not alcohol drinkers. Third, we showed the BRCA2 p.Lys3326X variant to be associated with increased risk of ESCC (OR = 3.38, 95%CI = 1.97-6.91; P = 2x10-4). Then, we hypothesized that the genes for Fanconi anemia may be candidate genes for ESCC and sequenced the entire coding regions of 12 Fanconi anemia genes in the germline DNA of 190 ESCC cases. We identified three heterozygous insertion/deletions in FANCD2, FANCE and FANCL. All three patients had a strong family history of ESCC. In addition, we found two homozygous patients for the deleterious FANCA p.Ser858Arg mutation. We found two more homozygotes in 556 more ESCC patients, but in none of 1373 matched controls (OR = 16.7, 95%CI = 6.2-44.2; P = 0.01). Finally, we implemented a pilot genome-wide association study in ESCC using 182 cases and 177 matched controls. None of the 1.2 M observed and imputed SNPs showed an association with ESCC at a genome-wide significance level. This showed that an ESCC susceptibility allele with OR>3 estimated from our familial risk study, is unlikely to be identified among common variants of the human genome and we should look for it among rare variants.Ph
The Impact of Pregnancy on Breast Cancer Survival in Women who Carry a BRCA1 or BRCA2 Mutation
Get PDFBackground: Young BRCA mutation carries with a history of breast cancer often inquire about the impact of pregnancy upon their risks of cancer recurrence and survival.
Methods: We identified 128 BRCA carriers who were diagnosed with breast cancer while pregnant or who became pregnant after breast cancer diagnosis. Women were matched to 269 controls. Women were followed from the date of breast cancer diagnosis until the date of death. The Kaplan-Meier method and a left-truncated Cox proportional hazard model were used to estimate 15-year survival rates.
Results: The adjusted hazard ratio associated with 15-year survival for women diagnosed with breast cancer who were or became pregnant after breast cancer diagnosis, compared to women who did not become pregnant was 0.76 (95% CI 0.31 to 1.91 p = 0.56).
Conclusion: Pregnancy concurrent with or after a diagnosis of breast cancer does not appear to adversely affect survival among BRCA1/2 mutation carriers.MAS
The Impact of Prophylactic Salpingo-oophorectomy on Health in Women who carry a BRCA1 or BRCA2 Mutation
No full textProphylactic salpingo-oophorectomy, the preventive removal of the ovaries and fallopian tubes, is recommended to women who carry a BRCA1 or BRCA2 mutation in order to reduce the risk of breast, ovarian and fallopian tube cancer. The short and long term health and quality of life effects of this procedure are not well understood. We examined the actual and perceived reduction in cancer risk associated with this surgery. The impact of prophylactic salpingo-oophorectomy on health-related quality of life, psychological distress, cancer worry, menopausal symptoms, and sexual function during the year following surgery was also evaluated. In our prospective study, prophylactic salpingo-oophorectomy was associated with an 80% reduction in ovarian and fallopian tube cancer risk. The residual risk for primary peritoneal cancer was 0.2% per year or 4.3% at 20 years after salpingo-oophorectomy. Most women accurately perceived their risk of breast cancer. However, the risk for ovarian cancer was overestimated, particularly by women who carry a BRCA2 mutation. Physical and mental health-related quality of life did not decrease in the year following surgery; and psychological distress was similar to levels experienced by the general population. Most women were significantly less worried about cancer after the surgery, however, a subset of women continued to experience significant cancer specific distress after prophylactic salpingo-oophorectomy. Women who underwent prophylactic salpingo-oophorectomy when premenopausal experienced a significant worsening of vasomotor symptoms and a decline in sexual functioning. Hormone replacement therapy mitigated these symptoms, but not to pre-surgical levels. Dyspareunia was somewhat alleviated by hormone replacement therapy, however, the decrease in sexual pleasure was not. Satisfaction with the decision to undergo prophylactic salpingo-oophorectomy was high regardless of these symptoms. These studies will provide women who are considering prophylactic salpingo-oophorectomy with information about the reduction in cancer risk associated with the surgery and the possible effects experienced during the year following surgery.Ph
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