Risk assessment and prevention of breast cancer

One woman in eight develops breast cancer during her lifetime in the Western world. Measures are warranted to reduce mortality and to prevent breast cancer. Mammography screening reduces mortality by early detection. However, approximately one fourth of the women who develop breast cancer are diagnosed within two years after a negative screen. There is a need to identify the short-term risk of these women to better guide clinical followup. Another drawback of mammography screening is that it focuses on early detection only and not on breast cancer prevention. Today, it is known that women attending screening can be stratified into high and low risk of breast cancer. Women at high risk could be offered preventive measures such as low-dose tamoxifen to reduce breast cancer incidence. Women at low risk do not benefit from screening and could be offered less frequent screening. In study I, we developed and validated the mammographic density measurement tool STRATUS to enable mammogram resources at hospitals for large scale epidemiological studies on risk, masking, and therapy response in relation to breast cancer. STRATUS showed similar measurement results on different types of mammograms at different hospitals. Longitudinal studies on mammographic density could also be analysed more accurate with less nonbiological variability. In study II, we developed and validated a short-term risk model based on mammographic features (mammographic density, microcalcifications, masses) and differences in occurrences of mammographic features between left and right breasts. The model could optionally be expanded with lifestyle factors, family history of breast cancer, and genetic determinants. Based on the results, we showed that among women with a negative mammography screen, the short-term risk tool was suitable to identify women that developed breast cancer before or at next screening. We also showed that traditional long-term risk models were less suitable to identify the women who in a short time-period after risk assessment were diagnosed with breast cancer. In study III, we performed a phase II trial to identify the lowest dose of tamoxifen that could reduce mammographic density, an early marker for reduced breast cancer risk, to the same extent as standard 20 mg dose but cause less side-effects. We identified 2.5 mg tamoxifen to be non-inferior for reducing mammographic density. The women who used 2.5 mg tamoxifen also reported approximately 50% less severe vasomotor side-effects. In study IV, we investigated the use of low-dose tamoxifen for an additional clinical use case to increase screening sensitivity through its effect on reducing mammographic density. It was shown that 24% of the interval cancers have a potential to be detected at prior screen. In conclusion, tools were developed for assessing mammographic density and breast cancer risk. In addition, two low-dose tamoxifen concepts were developed for breast cancer prevention and improved screening sensitivity. Clinical prospective validation is further needed for the risk assessment tool and the low-dose tamoxifen concepts for the use in breast cancer prevention and for reducing breast cancer mortality

Testing Theories of Job Creation: Does Supply Create Its Own Demand?

Although search-matching theory has come to dominate labor economics in recent years, few attempts have been made to compare the empirical relevance of search-matching theory to efficiency wage and bargaining theories, where employment is determined by labor demand. In this paper we formulate an empirical equation for net job creation, which encompasses search-matching theory and a standard labor demand model. Estimation on firm-level data yields support for the labor demand model, wages and product demand affect job creation, but we find no evidence that unemployed workers contribute to job creation, as predicted by search-matching theory.job creation, involuntary unemployment, search-matching, labor demand, competitiveness

Coupling and Brightness Considerations for the MAX IV 3 GeV Storage Ring

It is often suggested that the emittance coupling of a storage ring should be adjusted to the so-called diffraction limit corresponding to the shortest wavelength of interest. For 1 Å radiation this leads to a typical requirement of 8 pm rad vertical emittance. In ultralow-emittance storage rings like the MAX IV 3 GeV storage ring this corresponds to a comparably large setting of the emittance coupling (2.5%). This approach, however, does not produce the brightest radiation and needs to be revisited taking into account that overall photon brightness depends on the emittances of the electron beam and the intrinsic photon beam. This paper summarizes an analytic approach to maximizing brightness as a function of emittance coupling while retaining sufficient lifetime. Instead of "meeting the diffraction limit", we further reduce the coupling, thus increasing both the brightness and transverse coherence of the emitted radiation. We derive that reducing the MAX IV 3 GeV storage ring's vertical emittance to 2 pm rad (0.6% coupling) will increase brightness and transverse coherence by almost a factor two while 10 h overall lifetime can still be achieved

MAX IV Emittance Reduction and Brightness Improvement

With MAX IV construction well underway and beam commissioning expected to commence in July 2015, first studies have been launched on improving the optics of the MAX IV 3 GeV storage ring with the goal of further reducing the emittance from the baseline design (320 pm rad) towards 150 pm rad while improving the matching of the electron beam to insertion devices to further improve the resulting photon brightness. We report on progress in the development of this new optics as well as studies of the impact of many strong insertion devices on beam emittance. The latter is an crucial issue in ultralow-emittance rings where dipole radiation losses are low and hence the equilibrium emittance is determined to large extent by the insertion devices. Additionally, large stored current can lead to a significant increase of emittance via strong intrabeam scattering in both transverse and longitudinal planes. Hence, the anticipated insertion devices, stored bunch current, and RF cavity tuning all have to be taken into account when optimizing for highest brightness. We present initial results and sketch a path towards a first MAX IV upgrade

Demo Abstract: EmuLink - Heterogeneous Sensor Network Simulation in Cooja

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Product market imperfections and employment dynamics

How important is imperfect competition in the product market for employment dynamics? To investigate this, we formulate a theoretical model of employment adjustment with imperfect competition in the product market, search frictions, and convex adjustment costs. From this model, we derive a structural equation for employment that we estimate on firm-level data. We find that product market demand shocks have significant and quantitatively large effects on employment. Thus, product market imperfections seem to be important for employment dynamics. However, we find no evidence that the tightness of the local labor market affects job creation in existing firms

Prognostication of assortments from standing forests with available data : adapted to Sveaskog Norrbottens planning process

This study in the subject of forest planning is made for Sveaskog and its aim is to develop tools that prognosticate outcome in terms of volumes per sort from not yet cut forest stands. The degree of detail is just to get reliable results for at least one months volumes, for Sveaskogs own forestland in the market region of Norrbotten that is about 100 000 m3fub. The course of action to accomplish this is regression analysis and the data consists of cut tracts on own forestland in Norrbotten during the years 2006, 2007 and 2008. That is a little more than 4 million m3fub. Two tools were made. One that uses planned tracts data (PT) for computation and one that uses the stand register data (BR). The PT-tool has the best precision of basically two obvious reasons. First PT is further in the supply chain and therefore closer to the answer, the industry measuring. Second, BR had some pretty serious practical issues attached to it at this time. An internal validation was made with all the data and it showed that the calculated total volume for PT was 0,2 % below the true volume and the same volume for BR was 4,7 % above. More detailed, roughly the PT-tool estimates all sorts but burning wood and GROT fair while the BR-tool estimates all sorts but pine and spruce timber poor. Finally, the aim of the study is reached because the tools are completed and the PT-tool shows promising results for practical use while the BR-tool right now can be tested but later be redone with better structured data

Severe trauma : risks and outcomes

Trauma, “the neglected disease of modern society”, is a global health concern of enormous proportions. Knowledge about factors associated with trauma occurrence, complications and outcome is highly valuable for the improvement of trauma care. This thesis, aiming at deeper knowledge regarding trauma occurrence and outcome, used regional and national registers in four epidemiological studies with different methodologies. Prior to injury, trauma patients were treated for psychiatric disorders, substance abuse and somatic disorders to a greater extent than matched controls. Moreover, low income and low education, psychiatric disorders, substance abuse and somatic disorders were all independent risk factors for trauma after adjustment for confounders. These insights could facilitate implementation of injury prevention strategies. Severely injured patients that use β-adrenergic receptor antagonists (β-blockers) at the time of trauma had an increased mortality compared to non-users, β-blockers could thus be seen as an indicator for increased risk of death. However, after adjustment for relevant confounders no increased risk, or benefit, of β-blockers per se was noted. The protective effect of β-blockade after severe trauma suggested by previous reports could not be supported. Prospective randomized trials are needed to elucidate a role, if any, for β-blockade in the trauma setting. Acute kidney injury (AKI) affected one quarter of patients treated in the intensive care unit (ICU) following severe trauma. AKI was strongly associated with increased risk of death at 30 days and after one year. For those treated with renal replacement therapy the risk of chronic dialysis dependency after the intensive care period appears to be very low. Comorbidities such as diabetes mellitus as well as greater injury severity were strongly associated with post-injury AKI. Among preventable factors an association between resuscitation with hydroxyethyl starch (HES) and increased risk of AKI warrants caution. Administration of nephrotoxic substances should be avoided and targeted interventions may be provided to the patient at risk. Finally, trauma patients had a sustained increase in mortality several years after the index trauma. External causes, including new trauma, were far more common causes of late death in injured patients than in the background population. These findings support the concept of trauma recidivism. Two subgroups of deceased individuals could be identified; younger patients with a high prevalence of psychiatric disorders and substance abuse dying from external causes including suicide, and an older subgroup with a burden of somatic comorbidities dying from cardiovascular disorders and neoplasms. These findings emphasize the need for improved follow-up strategies and secondary prevention