Operating regime and stability of mode-locking in 10GHz quantum dot laser diodes around 1.5µm

In this paper we investigate and explore the stability and operating regime of modelocking (ML) in 4mm long Fabry-Perot type lasers, corresponding to a roundtrip frequency of 10GHz. The devices are fabricated on InAs/InP quantum dot material, operating at wavelengths around 1.5um, and are HR-coated at the absorber side. In order to find the stable ML region of operation in these devices, we have performed sweep-scans on the injection current of the gain section, and the reverse bias voltage on the absorber section. We will present the optical and electrical spectrum of devices with different absorber length. These results will be compared with the performance of earlier devices without HR coating

Quality of life of elderly persons with newly diagnosed cancer.

The aim was to investigate quality of life (QoL) in elderly persons newly diagnosed with cancer (65+ years) in relation to age, contact with the health-care system, ability to perform activities of daily living (ADL), hope, social network and support, and to identify which factors were associated with low QoL. The sample consisted of 101 patients (75 women and 26 men) newly diagnosed with cancer. EORTC QLQ-C30, Nowotny's Hope Scale, Katz ADL and the Interview Schedule for Social Interaction (ISSI) were used. The analysis was carried out in four age groups and revealed no significant differences in QoL. Compared with the other age groups, those of a high age (80+ years) more often lived alone, used more home-help service and had a smaller social network. Factors associated with low QoL were 'no other incomes than retirement pension', 'low level of hope' and 'lung cancer'. In addition, 'being told that the cancer disease has not come to an end', 'needing more help in activities of daily living', 'getting help from grown-up children' and 'needing help with PADL' were associated with low QoL. Those at risk of inferior QoL, that is, having poor economy, low level of hope and lung cancer need special attendance and specific interventions to improve QoL

Assessing Writing Motivation: a Systematic Review of K-5 Students' Self-Reports

For attaining success in writing, motivation is essential. Crucially, instruction is dependent on knowing the student’s capabilities and inner drives. To date, research on writing has yet to establish a consistent framework for assessing writing motivation, and often fails to acknowledge students’ self-reports, rather favoring evaluations of students’ writing motivation made by others, such as teachers and researchers. This limbo state originates partly from a general skepticism towards the trustworthiness of elementary students’ self-reports. Nonetheless, the validity of such self-reports has been acknowledged in adjacent fields, such as reading. Aiming to establish a knowledge base from studies addressing students’ voices, the present study adopts the method of a systematic review and investigates how writing motivation has been assessed in empirical studies (1996–2020) through K-5 students’ self-reports. Of the 7047 studies identified through database search, 56 met the inclusion criteria and are examined in this review. Results indicate that (a) storytelling is the genre most used to operationalize writing in the investigations, (b) surveys and interview questions measuring students’ attitude towards writing are the most common type of self-report used, and (c) students’ voices are weighted differently across the studies. Findings suggest that future research should (1) work to counteract existing biases in writing tasks, (2) provide a rationale for their choice/design of measure of motivation, and (3) report clearly whose voices are being heard (e.g., students’, teachers’, or researchers’) and the appropriateness of this choice regarding study purpose, design, and findings.publishedVersio

Developmental Dynamics of Early Reading Skill, Literacy Interest and Reader Self-Concept Within the First Year of Formal Schooling

Previous studies have documented robust relationships between emergent literacy and later reading performance. A growing body of research has also reported associations between motivational factors and reading in early phases of reading development. However, there is less research about cross-lagged relationships between motivational factors and reading skills in beginning readers. To examine relationships between early reading skills, literacy interest and reader self-concept, we tested 1141 children twice during their first year of formal reading instruction in school. Cross-lagged analysis showed strong stability in reading skills and medium stability in literacy interest and reader self-concept over the first school year. We also found bidirectional relationships between reading skills and self-concept and between the motivational components of literacy interest and reader self-concept. In the final part of the article, we address the potential theoretical progress attainable through the use of cross-lagged designs in this field.publishedVersio

The meaning of having to live with cancer in old age.

Little is known about how older people with cancer experience their life situation. To increase the understanding of how illness is experienced in older people with cancer, the aim of this study was to investigate the meaning of living with cancer in old age. The hermeneutic phenomenological method as described by van Manen and referred to as 'phenomenology of praxis' was used. Ten persons (seven women and three men) aged 75 and over, who had a diagnosis of cancer and who had just completed cancer treatment, were interviewed in their own homes. The analysis revealed a life world affected to varying degrees by the cancer disease. The lived experiences across the interviews were revealed in four overarching essential themes: transition into a more or less disintegrated existence, sudden awareness of the finiteness of life, redefinition of one's role in life for good and for bad, meeting disease and illness. To provide individual support and appropriate care to older people with cancer it is important for health care professionals to identify and take care of disabilities and to support the reorientation in the disintegrated life situation. It is also important to have preparedness to meet the old person's thoughts about death. Thus, it is important to encourage the old person to describe her/his illness experience to increase understanding about what is meaningful for her/him

Fatty acid metabolism in Atlantic salmon (Salmo salar L.) hepatocytes and influence of dietary vegetable oil

Isolated hepatocytes from Atlantic salmon (Salmo salar), fed diets containing either 100% fish oil or a vegetable oil blend replacing 75% of the fish oil, were incubated with a range of seven 14C-labelled fatty acids. The fatty acids were; [1-14C]16:0, [1-14C]18:1n-9, [1-14C]18:2n-6, [1-14C]18:3n-3, [1-14C]20:4n-6, [1-14C]20:5n-3, and [1-14C]22:6n-3. After 2 hours of incubation the hepatocytes and medium were analyzed for acid soluble products, incorporation into lipid classes, and hepatocytes for desaturation and elongation. Uptake into hepatocytes was highest with [1-14C]18:2n-6 and [1-14C]20:5n-3 and lowest with [1-14C]16:0. The highest recovery of radioactivity in the cells was found in triacylglycerols. Of the phospholipids the highest recovery was found in phosphatidylcholine, with [1-14C]16:0 and [1-14C]22:6n-3 being the most prominent fatty acids. The rates of β-oxidation were as follows: 20:4n-6 > 18:2n-6 = 16:0 > 18:1n-9 > 22:6n-3 = 18:3n-3 = 20:5n-3. Of the fatty acids taken up by the hepatocytes, [1-14C]16:0 and [1-14C]18:1n-9 were subsequently exported the most, with the majority of radioactivity recovered in phospholipids and triacylglycerols, respectively. The major products from desaturation and elongation were generally one cycle of elongation of the fatty acids. Diet had a clear effect on the overall lipid metabolism, with replacing 75% of the fish oil with vegetable oil resulting in decreased uptake of all fatty acids and reduced incorporation of fatty acids into cellular lipids, but increased β-oxidation activity, and higher recovery in products of desaturation and elongation of [1-14C]18:2n-6 and [1-14C]18:3n-3

Passively modelocked 15, 20 and 40 Ghz bulk InGaAsP lasers

Passively modelocked linear lasers have been fabricated using bulk InGaAsP/InP material. Modelocking in 20 GHz self colliding pulse modelocked lasers and 40 GHz colliding pulse lasers has been demonstrated and the devices have been characterized. Pulse lengths down to 1.6 ps have been observed from a linear device at 20GHz. 15GHz modelocked ring lasers have been fabricated as well. In order to avoid internal reflections in the ring, the design employs successfully adiabatic bends and a directional coupler. Measurements with a 50GHz RF analyzer showed more stable operation than the linear devices, but pulses are highly chirped. The layer stack used for these lasers is compatible with our active-passive integration scheme

Observation and modeling of long-wavelength InAs/InP (100) quantum dot amplifier small signal gain spectra

Measured gain spectra from InAs/InP (100) quantum-dot amplifiers have been analyzed with a quantum-dot rate-equation model. The amplifiers are fabricated to have a peak gain wavelength around 1700nm. Our comparison between measured and simulated gain spectra shows that two effects in the quantum-dot material introduce the 65 nm blue shift and change in shape that have been observed in the measured gain spectrum with an increase in injection current density from 1000A/cm2 to 3000A/cm2. The first effect is the shift from GS to ES, and the second effect the dot size dependent filling due to the dot size dependent escape rates

Analysis of the performance of InAs/InP(100) quantum dot waveguide photodetectors using a rate quation model

In this contribution we present a rate equation model for the simulation of InAs/InP(100) quantum dots which are used as the active material of waveguide photodetectors. Unlike the normal rate equation models in literature which are built for carrier injection and photon emission, our model is modified for the carrier extraction and photon absorption. The simulation results are compared with previous experimental results. Experimental observations are explained in terms of fundamental properties of the quantum dots, e.g. the bias voltage dependent carrier extraction rate and absorption coefficient