Progress towards photonic crystal quantum cascade laser

The work describes recent progress in the design, simulation, implementation and characterisation of photonic crystal (PhC) GaAs-based quantum cascade lasers (QCLs). The benefits of applying active PhC confinement around a QCL cavity are explained, highlighting a route to reduced threshold current operation. Design of a suitable PhC has been performed using published bandgap maps; simulation results of this PhC show a wide, high reflectivity stopband. Implementation of the PhC for the device is particularly difficult, requiring a very durable metallic dry etch mask, high performance dry etching and a low damage epilayer-down device mounting technique. Preliminary shallow etched PhC QCLs demonstrated the viability of current injection through the metal etch mask and the device mounting technique. Development of the etch mask and dry etching have demonstrated a process suitable for the manufacture of deep etched PhC structures. All the necessary elements for implementing deep etched PhC QCLs have now been demonstrated, allowing for the development of high performance devices

The role of high growth temperature GaAs spacer layers in 1.3-/spl mu/m In(Ga)As quantum-dot lasers

We investigate the mechanisms by which high growth temperature spacer layers (HGTSLs) reduce the threshold current of 1.3-/spl mu/m emitting multilayer quantum-dot lasers. Measured optical loss and gain spectra are used to characterize samples that are nominally identical except for the HGTSL. We find that the use of the HGTSL leads to the internal optical mode loss being reduced from 15 /spl plusmn/ 2 to 3.5 /spl plusmn/ 2 cm/sup -1/, better defined absorption features, and more absorption at the ground state resulting from reduced inhomogenous broadening and a greater dot density. These characteristics, together with a reduced defect density, lead to greater modal gain at a given current density

The role of psychosocial variables in physician judgement of pain-related disability

Objective: The current study aimed to determine the extent to which physicians take psychosocial factors into account when making pain-related judgements of disability. Subjects and Method: 228 chronic pain patients completed the West Haven-Yale Multidimensional Pain Inventory (WHYMPI), while 69 completed both this instrument and the Addiction Potential, Anxiety, Health Concerns and Depression supplementary subscales of the Minnesota Multiphasic Personality Inventory – 2 (MMPI-2). Physicians were required to provide diagnoses, as well as ratings of functional ability for each patient. Hierarchical regression analyses were conducted in order to determine the degree to which psychosocial variables predicted physician ratings of patient functional ability. Results: Psychosocial variables were found to predict physician assessments of patients’ level of occupational functioning, general satisfaction with life and physician perceptions of the role that psychosocial their risk of analgesic dependence. Depression and anxiety symptoms predicted factors played in patients’ pain experiences. Health concerns were predictive of physician assessments of analgesic dependence amongst patients. Conclusion: While certain psychosocial factors appear to be considered by physicians during pain-related disability assessment, psychiatric symptoms and physical pathology seem to weigh heavier in the process.Key Words: Disability, functional ability, chronic pain, psychosocial, psychopathology, health concerns, WHYMPI, MMPI-

SDSU Calf Value Discovery 2011 Summary Report

The Calf Value Discovery Program (CVD) allows cow-calf producers to gain knowledge of the finishing segment of the beef cattle industry and the marketing of fed cattle. Specifically, CVD provides an opportunity for cow-calf producers to learn how their calves perform in a feedlot and their carcass value when sold in a value-based marketing system. Each producer taking part in the program could consign a minimum of 5 steers weighing between 500 and 800 pounds to the CVD program. Animals were finished in a calf-fed program using typical diets and management protocols at VanderWal Yards (Bruce, SD). Carcass and feedlot performance information from calves were returned to producers for use in making future management decisions to improve profitability

Marine introductions in the Shark Bay World Heritage Property, Western Australia: A preliminary assessment

The presence and impacts of non-indigenous species (NIS) in marine areas of high conservation or World Heritage significance have rarely been examined. Case studies worldwide suggest that the potential exists for the introduction of NIS to significantly impact conservation values in regions conserved for the uniqueness and diversity of native assemblages. In this study, a preliminary investigation was conducted to provide information essential for managing marine introductions in the Shark Bay World Heritage Property. A focused fouling plate survey sampled a total of 112 encrusting taxa, of which 10 (11.2%) were classified as introduced and 10 others as cryptogenic. Eight introduced bryozoans: Aetea anguina (Linnaeus, 1758), Bugula neritina (Linnaeus, 1758), Bugula stolonifera Ryland, 1960, Conopeum seurati (Canu, 1928), Savignyella lafontii (Audouin, 1826), Schizoporella errata (Waters, 1878), Watersipora subtorquata (d’Orbigny, 1842) and Zoobotryon verticellatum della Chiaje, 1828; one tunicate, Styela plicata Lesueur, 1823; and an introduced hydroid, Obelia dichotoma (Linnaeus, 1758) were frequent, and in some cases dominant, components of encrusting communities. Of the 20 most frequently occurring species detected in the Bay, four were introduced and of the 20 species with highest average percent cover per plate, six were introduced. At one site, space occupation by NIS averaged 71.6% ± 7.4 of plate live cover. Space occupation by an individual NIS was as high as 62.4% of plate area (mean 7.82% ± 1.8). NIS were detected at sites lacking commercial traffic and ballast water discharge and isolated by distance and physical environment, suggesting that hull fouling of recreational craft may be the most important vector in the region. Seventy-five percent of NIS detected in Shark Bay are established in Australian ports to the south of Shark Bay, while 33% are established to the north, tentatively implicating temperate affinity NIS and the movement of vessels from Australian ports south of Shark Bay as a greater risk to the region

Oestrogen receptor positive breast cancer metastasis to bone: inhibition by targeting the bone microenvironment in vivo

Clinical trials have shown that adjuvant Zoledronic acid (ZOL) reduces the development of bone metastases irrespective of ER status. However, post-menopausal patients show anti-tumour benefit with ZOL whereas pre-menopausal patients do not. Here we have developed in vivo models of spontaneous ER+ve breast cancer metastasis to bone and investigated the effects of ZOL and oestrogen on tumour cell dissemination and growth. ER+ve (MCF7, T47D) or ER−ve (MDA-MB-231) cells were administered by inter-mammary or inter-cardiac injection into female nude mice ± estradiol. Mice were administered saline or 100 μg/kg ZOL weekly. Tumour growth, dissemination of tumour cells in blood, bone and bone turnover were monitored by luciferase imaging, histology, flow cytometry, two-photon microscopy, micro-CT and TRAP/P1NP ELISA. Estradiol induced metastasis of ER+ve cells to bone in 80–100 % of animals whereas bone metastases from ER−ve cells were unaffected. Administration of ZOL had no effect on tumour growth in the fat pad but significantly inhibited dissemination of ER+ve tumour cells to bone and frequency of bone metastasis. Estradiol and ZOL increased bone volume via different mechanisms: Estradiol increased activity of bone forming osteoblasts whereas administration of ZOL to estradiol supplemented mice decreased osteoclast activity and returned osteoblast activity to levels comparable to that of saline treated mice. ER−ve cells require increased osteoclast activity to grow in bone whereas ER+ve cells do not. Zol does not affect ER+ve tumour growth in soft tissue, however, inhibition of bone turnover by ZOL reduced dissemination and growth of ER+ve breast cancer cells in bone

Effects of Methylene Blue and Polyethelene Glycol on Facial Nerve Axotomy Recovery

poster abstractInjury and disease are common factors affecting peripheral nerves and can lead to loss of function. Recovery time after an injury is slow and not very efficient in humans. Treatment methods involving methylene blue (MB) and polyethylene glycol (PEG) have shown combinational effects in sciatic nerve axotomies. We are using behavior analysis of eye blink reflex and vibrissae orientation and movement as a measurement of rate of functional recovery. We will have treatment groups of both cut and crush rats. For each group we will be testing the effect of PEG/MB or no treatment control groups. The results of these treatment groups are significant to finding treatment options for clinical use

Repetitive task training for improving functional ability after stroke

<p><b>Objectives:</b> The objective of this review was to determine if repetitive task training after stroke improves global, upper, or lower limb function and if treatment effects are influenced by the amount, type, or timing of practice.</p> <p><b>Search Strategy:</b> We searched the Cochrane Stroke Trials Register (to October 2006); The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, SportDiscus, Science Citation Index, Index to Theses, ZETOC, PEDro, and OT Seeker (all to September 2006); and OT search (to March 2006). We also searched for unpublished/non-English language trials; combed conference proceedings and reference lists; requested information on bulletin boards; and contacted trial authors.</p> <p><b>Selection Criteria:</b> Selection criteria included randomized/quasirandomized trials in adults after stroke, of interventions that included an active motor sequence performed repetitively within a single training session, a clear functional goal, and a quantifiable level of practice.</p> <p><b>Data Collection and Analysis:</b> Two authors independently screened abstracts, extracted data, and appraised trial quality. Further information was obtained from study authors. Results from individual trials were combined using meta-analytic techniques appropriate to the data extracted and the level of between-trial heterogeneity.</p> <p><b>Main Results:</b> Fourteen trials with 17 intervention-control pairs and 659 participants were included. Primary outcomes showed that treatment effects were statistically significant for walking distance (see the Figure); walking speed (standardized mean difference, 0.29; 95% CI, 0.04 to 0.53); and sit-to-stand (standardized effect estimate, 0.35; 95% CI, 0.13 to 0.56). Treatment effects were of borderline statistical significance for functional ambulation.</p&gt

Seeking Evolution of Dark Energy

We study how observationally to distinguish between a cosmological constant (CC) and an evolving dark energy with equation of state $\omega(Z)$. We focus on the value of redshift Z* at which the cosmic late time acceleration begins and $\ddot{a}(Z^{*}) = 0$. Four $\omega(Z)$ are studied, including the well-known CPL model and a new model that has advantages when describing the entire expansion era. If dark energy is represented by a CC model with $\omega \equiv -1$, the present ranges for $\Omega_{\Lambda}(t_0)$ and $\Omega_m(t_0)$ imply that Z* = 0.743 with 4% error. We discuss the possible implications of a model independent measurement of Z* with better accuracy.Comment: 9 pages, LaTeX, 5 figure

The Scottish Mental Survey 1932 linked to the Midspan studies: a prospective investigation of childhood intelligence and future health

The Scottish Mental Survey of 1932 (SMS1932) recorded mental ability test scores for nearly all of the age group of children born in 1921 and at school in Scotland on 1st June 1932. The Collaborative and Renfrew/Paisley studies, two of the Midspan studies, obtained health and social data by questionnaire and a physical examination in the 1970s. Some Midspan participants were born in 1921 and may have taken part in the SMS1932, so might have mental ability data available from childhood. The 1921-born Midspan participants were matched with the computerised SMS1932 database. The total numbers successfully matched were 1032 out of 1251 people (82.5%). Of those matched, 938 (90.9%) had a mental ability test score recorded. The mean score of the matched sample was 37.2 (standard deviation [SD] 13.9) out of a possible score of 76. The mean (SD) for the boys and girls respectively was 38.3 (14.2) and 35.7 (13.9). This compared with 38.6 (15.7) and 37.2 (14.3) for boys and girls in all of Scotland. Graded relationships were found between mental ability in childhood, and social class and deprivation category of residence in adulthood. Being in a higher social class or in a more affluent deprivation category was associated with higher childhood mental ability scores and the scores reduced with increasing deprivation. Future plans for the matched data include examining associations between childhood mental ability and other childhood and adult risk factors for disease in adulthood, and modelling childhood mental ability, alongside other factors available in the Midspan database, as a risk factor for specific illnesses, admission to hospital and mortality