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Communal resources in open source software development
Introduction: Virtual communities play an important role in innovation. The paper focuses on the particular form of collective action in virtual communities underlying as Open Source software development projects.
Method: Building on resource mobilization theory and private-collective innovation, we propose a theory of collective action in innovative virtual communities. We identify three communal resources (reputation, control over technology and learning opportunities) that appear as a byproduct while developing open source software.
Analysis:Constructs are derived from exiting literature. Empirical data from Freenet, an open source software project for peer-to-peer software, illustrates both the levels of involvement and the communal resources.
Results & conclusions: Communal resources are able to solve the collective action dilemma for virtual communities. We show that they increase in value for individuals along with their involvement in the community
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Carrots and Rainbows: Motivation and Social Practice in Open Source Software Development
Open source software (OSS) is a social and economic phenomenon that raises fundamental questions about the motivations of contributors to information systems development. Some developers are unpaid volunteers who seek to solve their own technical problems, while others create OSS as part of their employment contract. For the past 10 years, a substantial amount of academic work has theorized about and empirically examined developer motivations. We review this work and suggest considering motivation in terms of the values of the social practice in which developers participate. Based on the social philosophy of Alasdair MacIntyre, we construct a theoretical framework that expands our assumptions about individual motivation to include the idea of a long-term, value-informed quest beyond short-term rewards. This motivation-practice framework depicts how the social practice and its supporting institutions mediate between individual motivation and outcome. The framework contains three theoretical conjectures that seek to explain how collectively elaborated standards of excellence prompt developers to produce high-quality software, change institutions, and sustain OSS development. From the framework, we derive six concrete propositions and suggest a new research agenda on motivation in OSS
Medical ovariectomy in menopausal breast cancer patients with high testosterone levels : a further step toward tailored therapy
Five years of adjuvant therapy with anti-estrogens reduce the incidence of disease progression by about 50% in estrogen receptor-positive breast cancer patients, but late relapse can still occur after anti-estrogens have been discontinued. In these patients, excessive androgen production may account for renewed excessive estrogen formation and increased risks of late relapse. In the 50% of patients who do not benefit with anti-estrogens, the effect of therapy is limited by de novo or acquired resistance to treatment. Androgen receptor and epidermal growth factor receptor overexpression are recognized mechanisms of endocrine resistance suggesting the involvement of androgens as activators of the androgen receptor pathway and as stimulators of epidermal growth factor synthesis and function. Data from a series of prospective studies on operable breast cancer patients, showing high serum testosterone levels are associated to increased risk of recurrence, provide further support to a role for androgens in breast cancer progression. According to the above reported evidence, we proposed to counteract excessive androgen production in the adjuvant setting of estrogen receptor-positive patients and suggested selecting postmenopausal patients with elevated levels of serum testosterone, marker of ovarian hyperandrogenemia, for adjuvant treatment with a gonadotropins-releasing hormone analogue (medical oophorectomy) in addition to standard therapy with anti-estrogens. The proposed approach provides an attempt of personalized medicine that needs to be further investigated in clinical trials
Стресорні порушення морфологічних показників крові качок у критичні періоди онтогенезу
The article presents data hematol ohichnyh performance blood of ducks in critical periods of postnatal ontogenesis 2, 14, 21, 45, 90, 150, and 240 days of life, which are accordingly related to the full use of the yolk, intensive development of the digestive system and muscular tissue, change of fluff to the primary feather, juvenile molt, the beginning of the oviposition, the formation of the reproductive system and glands of the internal secretion, the continuation of the oviposition and the molt, which is accompanied by the complete renewal of the fine and medium feathers. Blood plays an important role in maintaining homeostasis , and studies of hematological parameters make it possible to assess the intensity of redox processes in tissues and organs, and studies of hematological parameters make it possible to estimate the intensity of redox processes in tissues and organs, namely the need for oxygen in connection with the physico-chemical and biochemical processes that occur in the body in the process of growth and development. They are dynamic and change with different factors faster than performance. The purpose of the study was to determine the dynamics of morphological parameters of duck blood during the critical periods of postnatal ontogeny . Research subject clinically healthy young Beijing duck meat breed performance direction. Changes in hematological parameters of ducks' blood reflect a picture of the impact of critical periods of ontogeny on ducks, characterized by 2 days of life, the numerical values of erythrocytes (2.45 ± 0.11 T/l) and the concentration of hemoglobin (102.90 ± 3.51 g/l), but the value of hematocrit was in the lower levels of physiological norms. While the leukocyte count of 31.20 ± 1.76 was close to the 240-day age, indicating high bird immunity after hatching , more likely to come from the use of yolk. In the study bird on the 14th day recorded an increase in the number of erythrocytes and leukocytes by 10.6 and 14.7%, hematocrit by 10.3% against a decrease in hemoglobin concentration by 12.8% (P < 0.05). At 21 days, the number of erythrocytes and hemoglobin concentration decreased by 8.2%, while hematocrit and leukocyte values approached the initial state of the experiment, amounting to 26.45 ± 2.40%, 32.06 ± 2.93 G/L. The presence of basophils in this age period indicates the launch of a chain of immune responses, indicating the formation of the immune system according to A. Malyukin. (2010). At day 45, erythrocytes and hemoglobin concentrations were reduced by 10.2% and 11.3% (P < 0.05), compared to the baseline period. During this period, hematocrit increased by 12.7%, which indicated an increase in blood cells in the ducts. Results at 90 days indicated a decrease in erythrocyte count by 14.3% (P < 0.05) and hemoglobin concentration by 11.8% (P < 0.05), while leukocyte count and hematocrit increased by 26.1 and 22.1% (P < 0.05) compared with ducklings of 2 days of age. In ducklings at 150 days of age, the erythrocyte count and hemoglobin concentration were close to the baseline, and the leukocyte count and hematocrit were increased by 19.6 and 39.3%, respectively (P < 0.05). At 240 days of ducklings life, an increase in the oxygen-transport system of blood was established in the form of an increase in the number of erythrocytes by 35.1% (P < 0.01), hemoglobin concentration by 28.7% (P < 0.01), hematocrit value by 50, 8% (P < 0.01) compared to 2-days of ducklings life, and the number of leukocytes was close to baseline, indicating a decrease in the reactivity of the organism.У статті наведені дані гематологічних показників крові качок у критичні періоди постнатального онтогенезу на 2, 14, 21, 45, 90, 150, 240 добу життя, які відповідно пов’язані з повним використання жовтка, інтенсивним розвитком травної системи і м’язової тканини, зміною пуху на первинне перо, ювенальною линькою, початком яйцекладки, формуванням репродуктивної системи і залоз внутрішньої секреції, продовженням яйцекладки та линьки, яка супроводжується повним оновленням дрібного і середнього пір’я. Важливу роль в підтриманні гомеостазу відіграє кров, а дослідження гематологічних показників дають можливість оцінювати інтенсивність окисно-відновних процесів у тканинах та органах, а саме потребу в кисні у зв’язку з фізико-хімічними та біохімічними процесами, які відбуваються в організмі в процесі росту і розвитку. Вони динамічні і змінюються за дії різних чинників швидше, ніж показники продуктивності. Метою роботи було визначити динаміку морфологічних показників крові качок у критичні періоди постнатального онтогенезу. Дослідженню підлягав клінічно здоровий молодняк пекінської породи качок м’ясного напрямку продуктивності. Зміни гематологічних показників крові качок відображають нам картину впливу критичних періодів онтогенезу на організм качок, що характеризуються на 2 добу життя – числові значення еритроцитів (2,45 ± 0,11 Т/л) та концентрації гемоглобіну (102,90 ± 3,51 г/л), проте величина гематокриту перебувала у нижчих рівнях фізіологічної норми. Кількість лейкоцитів 31,20 ± 1,76 Г/л була наближена до значень 240-добового віку, що свідчить про високий імунний захист птиці після вилуплення, найімовірніше отриманий від використання жовтка. У досліджуваній птиці на 14 добу реєстрували підвищення кількості еритроцитів і лейкоцитів на 10,6 і 14,7% , величини гематокриту на 10,3% на тлі зменшення концентрації гемоглобіну на 12,8% (Р < 0,05). На 21 добу кількість еритроцитів та концентрація гемоглобіну знижувалася на 8,2%, тимчасом як величина гематокриту і лейкоцити наближалися до вихідного стану експерименту, становила що 26,45 ± 2,40% , 32,06 ± 2,93 Г/л. Наявність базофілів у цьому віковому періоді свідчить про запуск ланцюгу імунних реакцій, що вказує на становлення імунної системи. На 45 добу в каченят виявлено зменшення кількості еритроцитів і концентрації гемоглобіну на 10,2% та 11,3% (Р < 0,05) порівняно з вихідним періодом. В цей період величина гематокриту підвищувалась на 12,7% , що вказувало на збільшення формених елементів крові у кровоносному руслі каченят. Отриманні результати на 90 добу життя вказували на зниження кількості еритроцитів на 14,3% (Р < 0,05) та концентрація гемоглобіну на 11,8% (Р < 0,05), тимчасом як кількість лейкоцитів і величина гематокриту зростали на 26,1 і 22,1% (Р < 0,05) порівняно з каченятами 2-добового віку. В каченят на 150 добу життя кількість еритроцитів та концентрація гемоглобіну наближалась до вихідного періоду експерименту, а кількість лейкоцитів і величина гематокриту підвищувалась на 19,6 і 39,3% (Р < 0,05). На 240 добу життя каченят встановлено підвищення киснево-транспортної системи крові у вигляді зростання кількості еритроцитів на 35,1% (Р < 0,01), концентрації гемоглобіну на 28,7% (Р < 0,01), величини гематокриту на 50,8% (Р < 0,01) порівняно з 2-добовими каченятами, а кількість лейкоцитів наближалось до вихідного стану, що свідчило про зниження реактивності організму
Usual energy and macronutrient intakes in 2-9-year-old European children
OBJECTIVE: Valid estimates of population intakes are essential for monitoring trends as well as for nutritional interventions, but such data are rare in young children. In particular, the problem of misreporting in dietary data is usually not accounted for. Therefore, this study aims to provide accurate estimates of intake distributions in European children.
DESIGN: Cross-sectional setting-based multi-centre study.
SUBJECTS: A total of 9560 children aged 2-9 years from eight European countries with at least one 24-h dietary recall (24-HDR).
METHODS: The 24-HDRs were classified in three reporting groups based on age- and sex-specific Goldberg cutoffs (underreports, plausible reports, overreports). Only plausible reports were considered in the final analysis (N=8611 children). The National Cancer Institute (NCI)-Method was applied to estimate population distributions of usual intakes correcting for the variance inflation in short-term dietary data.
RESULTS: The prevalence of underreporting (9.5%) was higher compared with overreporting (3.4%). Exclusion of misreports resulted in a shift of the energy and absolute macronutrient intake distributions to the right, and further led to the exclusion of extreme values, that is, mean values and lower percentiles increased, whereas upper percentiles decreased. The distributions of relative macronutrient intakes (% energy intake from fat/carbohydrates/proteins) remained almost unchanged when excluding misreports. Application of the NCI-Method resulted in markedly narrower intake distributions compared with estimates based on single 24-HDRs. Mean percentages of usual energy intake from fat, carbohydrates and proteins were 32.2, 52.1 and 15.7%, respectively, suggesting the majority of European children are complying with common macronutrient intake recommendations. In contrast, total water intake (mean: 1216.7 ml per day) lay below the recommended value for >90% of the children.
CONCLUSION: This study provides recent estimates of intake distributions of European children correcting for misreporting as well as for the daily variation in dietary data. These data may help to assess the adequacy of young children's diets in Europe
String Junctions and Bound States of Intersecting Branes
We study four-dimensional black hole configurations which result from
wrapping M5-branes on a Calabi-Yau manifold, as well as U-dual realizations.
Our aim is to understand the microscopic degrees of freedom responsible for the
existence of bound states of multiple branes. The details depend on the chosen
U-frame; in some cases, they are massless string junctions. We also identify a
perturbative description in which these states correspond to twisted strings of
intersecting D3-branes at an orbifold singularity. In each case, these are the
preponderant states of the spacetime infrared conformal field theory and
account for the entropy of the blackhole.Comment: 14 pages; 2 figures; uses latex with epsf and hyperref package
Cross-sectional and longitudinal associations between energy intake and BMI z-score in European children
Background: Evidence for the effect of dietary energy on BMI z-scores in young children is limited. We aim to investigate cross-sectional and longitudinal effects of daily energy intake (EI) on BMI z-scores of European boys and girls considering growth-related height dependencies of EI using residual EI. Methods: To investigate cross-sectional and longitudinal effects of daily energy intake (EI) on BMI z-scores of European boys and girls considering growth-related height dependencies of EI using residual EI. Methods: Subjects were children aged 2-<10 y old (N=2753, 48.2% girls) participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) baseline and follow-up examination. Usual EI (kcal/day) was calculated based on the National Cancer Institute-method excluding subjects with implausible reported EI. Effect of age, height and sex-adjusted residuals of EI on BMI z-score was investigated stratified by baseline age -group (2-<4 y, 4-<6 y, 6-<8 y and 8-<10 y) cross-sectionally using linear regression models adjusted for relevant confounders (crude model: age, sex, country; fully adjusted model: plus parental ISCED level, parental BMI, screen time; subgroup analysis: plus objectively measured physical activity). Longitudinal associations were estimated between changes in (¿) residual EI per year and ¿BMI z-score per year with adjustments analogously to the cross-sectional models but with additional adjustment for residual EI at baseline. Results: Cross-sectionally, positive associations were observed between residual EI and BMI z-score for the full study sample, for boys and in older (=6years) but not in younger children in the crude and fully adjusted model. Longitudinally, small positive associations were observed between ¿residual EI per y on ¿BMI z-score per y for the full study sample and in 4-<6 y olds in the crude and fully adjusted model. Conclusion: In conclusion, EI above the average intakes for a certain sex, age and height are weakly associated with BMI z-scores in European children. Residual EI may be considered as a useful exposure measure in children as it accounts for growth-related changes in usual EI during childhood
Pasta consumption and connected dietary habits: Associations with glucose control, adiposity measures, and cardiovascular risk factors in people with type 2 diabetes—TOSCA.IT study
Background: Pasta is a refined carbohydrate with a low glycemic index. Whether pasta shares the metabolic advantages of other low glycemic index foods has not really been investigated. The aim of this study is to document, in people with type-2 diabetes, the consumption of pasta, the connected dietary habits, and the association with glucose control, measures of adiposity, and major cardiovascular risk factors. Methods: We studied 2562 participants. The dietary habits were assessed with the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. Sex-specific quartiles of pasta consumption were created in order to explore the study aims. Results: A higher pasta consumption was associated with a lower intake of proteins, total and saturated fat, cholesterol, added sugar, and fiber. Glucose control, body mass index, prevalence of obesity, and visceral obesity were not significantly different across the quartiles of pasta intake. No relation was found with LDL cholesterol and triglycerides, but there was an inverse relation with HDL-cholesterol. Systolic blood pressure increased with pasta consumption; but this relation was not confirmed after correction for confounders. Conclusions: In people with type-2 diabetes, the consumption of pasta, within the limits recommended for total carbohydrates intake, is not associated with worsening of glucose control, measures of adiposity, and major cardiovascular risk factors
A novel approach to breast cancer prevention: reducing excessive ovarian androgen production in elderly women
Minimizing endogenous estrogen production and activity in women at high risk for breast cancer is a prominent approach to prevention of the disease. A number of clinical trials have shown that the administration of selective-estrogen receptor modulators or aromatase inhibitors significantly reduces the incidence of breast cancer in healthy women. Unfortunately, these drugs often produce adverse effects on the quality of life and are, therefore, poorly accepted by many women, even those who are at high risk for breast cancer. We propose a novel alternative approach to decreasing estrogen production: suppression of ovarian synthesis of the androgen precursors of estrogens by administration of long-acting gonadotropin-releasing hormone analogs to women with ovarian stromal hyperplasia. The specific target population would be elderly postmenopausal women, at increased risk of breast cancer, and with high blood levels of testosterone, marker of ovarian hyperandrogenemia, and recognized factor of risk for breast cancer. Testosterone levels are measured at baseline to identify women at risk and during the follow-up to evaluate the effectiveness of therapy. The postmenopausal ovary is an important source of excessive androgen production which originates from the ovarian interstitial cell hyperplasia frequently present in breast cancer patients. We propose to counter the source of androgen excess in women with ovarian stromal hyperplasia, thus reducing the substrate for estrogen formation without completely inhibiting estrogen synthesis. Available evidence indicates that gonadotropin-releasing hormone analogs can be safely used for breast cancer prevention in postmenopausal women
Nonperturbative dynamics for abstract (p,q) string networks
We describe abstract (p,q) string networks which are the string networks of
Sen without the information about their embedding in a background spacetime.
The non-perturbative dynamical formulation invented for spin networks, in terms
of causal evolution of dual triangulations, is applied to them. The formal
transition amplitudes are sums over discrete causal histories that evolve (p,q)
string networks. The dynamics depend on two free SL(2,Z) invariant functions
which describe the amplitudes for the local evolution moves.Comment: Latex, 12 pages, epsfig, 7 figures, minor change
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