Noise equivalent circuit of a semiconductor laser diode

The noise equivalent circuit of a semiconductor laser diode is derived from the rate equations including Langevin noise sources. This equivalent circuit allows a straightforward calculation of the noise and modulation characteristics of a laser diode combined with electronic components. The intrinsic junction voltage noise spectrum and the light intensity fluctuation of a current driven laser diode are calculated as a function of bias current and frequency

Intravenous versus subcutaneous drug administration. Which do patients prefer? A systematic review

BACKGROUND: Intravenous (IV) drug delivery is commonly used for its rapid administration and immediate drug effect. Most studies compare IV to subcutaneous (SC) delivery in terms of safety and efficacy, but little is known about what patients prefer. METHODS: A systematic review was conducted by searching seven electronic databases for articles published up to February 2014. Included studies were randomized controlled trials (RCTs) and/or crossover designs investigating patient preference for SC versus IV administration. The risk of bias in the RCTs was determined using the Cochrane Collaboration tool. Reviewers independently extracted data and assessed the risk of bias. Any discrepancies were resolved by consensus. RESULTS: The search identified 115 publications, but few (6/115) met the inclusion criteria. Patient populations and drugs investigated were diverse. Four of six studies demonstrated a clear patient preference for SC administration. Main factors associated with SC preference were time saving and the ability to have treatment at home. Only three studies used study-specific instruments to measure preference. CONCLUSIONS: Results suggest that patients prefer SC over IV delivery. Patient preference has clearly been neglected in clinical research, but it is important in medical decision making when choosing treatment methods as it has implications for adherence and quality of life. If the safety and efficacy of both administration routes are equivalent, then the most important factor should be patient preference as this will ensure optimal treatment adherence and ultimately improve patient experience or satisfaction. Future drug efficacy and safety studies should include contemporaneous, actual patient preference where possible, utilizing appropriate measures

Monolithic integration of a GaAlAs buried-heterostructure laser and a bipolar phototransistor

A GaAlAs buried-heterostructure laser has been monolithically integrated with a bipolar phototransistor. The heterojunction transistor was formed by the regrowth of the burying layers of the laser. Typical threshold current values for the lasers were 30 mA. Common-emitter current gains for the phototransistor of 100–400 and light responsivity of 75 A/W (for wavelengths of 0.82 µm) at collector current levels of 15 mA were obtained

One size does not fit all:A systematic review of training outcomes on residential youth care professionals' skills

Despite the importance of training residential youth care professionals to increase their professional competences and, by doing so, enabling them to cope with the many stressors encountered during their work – such as the serious behaviour problems of the adolescents with whom they work – little attention has been paid so far to the influence of training on the behaviour and skills of residential professionals. This study aims to gain greater insight into the effects of training on the skills of these professionals. We conducted a systematic literature review using the PsycINFO, Eric, SocIndex and Academic Search Premier databases. Within the twelve studies retrieved, the outcomes of nine different training programmes were examined. These nine training programmes include The Solution Strategy (TSS), (Professional) Skills for Residential Child Care Workers (PSRCCW/SRCCW), Therapeutic Crisis Intervention (for Youth Care Workers) (TCIYCW/TCI), Child Teacher Relationship Training (CTRT), a Brief Training Program (BTP), Social Skills Training (SST), Behavior Analysis Services Program (BASP), Mental Health Training (MHT), and a Brief Training Manual (BTM). Our results demonstrate that positive changes in professional skills can be obtained after a training course. TSS (in both studies), PSFCCW, SRCCW, TCI, CTRT, BTP, SST, BASP and BTM programmes are associated with positive outcomes at the individual or organisational level. However, two studies also found negative outcomes related to decreases in the perceived recognition of youth care workers’ value to the agency and a decrease in the knowledge and skills that they learned through training after six months (TSS [Hickey, 1994] and PSRCCW). In addition, other outcomes were also found. The most common ‘other’ outcome was a variable training effect on the professionals’ skills. Although we did find positive (and some negative) training outcomes on the professionals’ skills, none of the studies specified the training elements which caused these changes. More thorough empirical studies using an experimental or repeated case study design are needed to identify effective training elements which could further improve the effectiveness of interventions targeting youths in residential youth care

Water-level Trends in Aquifers of South Carolina

S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen

Highly enriched Betaproteobacteria growing anaerobically with p-xylene and nitrate

The identity of the microorganisms capable of anaerobic p-xylene degradation under denitrifying conditions is hitherto unknown. Here, we report highly enriched cultures of freshwater denitrifying bacteria that grow anaerobically with p-xylene as the sole organic carbon source and electron donor. Long curved rods, with 95% 16S rRNA gene sequence identity to Denitratisoma oestradiolicum, dominated the enrichment cultures (>91% of all cells), as detected by phylotype-specific probes. These Rhodocyclaceae microorganisms were distantly related to other denitrifying hydrocarbon-degrading Betaproteobacteria from the Azoarcus-Thauera clade. Complete oxidation p-xylene to CO(2) coupled to denitrification was suggested by quantitative measurements of substrate consumption. Metabolite analysis identified (4-methylbenzyl)succinate and (4-methylphenyl)itaconate, suggesting addition to fumarate as an initial activation reaction

Arctic shipping emissions inventories and future scenarios

This paper presents 5 km×5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow), aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO<sub>2</sub> emissions (~42 000 gigagrams) by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships

Judges’ perceptions of the Nebraska CASA program

This article discusses judges’ perceptions of Court Appointed Special Advocates (CASA) programs in the rural state of Nebraska, as reported in two online surveys. The goal of CASA is “to train and support volunteers in advocating for safe and permanent homes for abused and neglected children” (CASA for Children, 2013). One survey investigated the opinions of judges presiding in Nebraska counties that did not yet have a local CASA program; another was administered to judges in counties that did have a CASA program. Data from both surveys were analyzed separately and then compared to provide information regarding judges’ satisfaction with local programs and general perceptions of Nebraska CASA programs. Results contain a hopeful tone for the Nebraska CASA Association and their goal of providing every child a voice by 2020 and provide vital information for program growth. This study could inform other states’ CASA programs seeking similar information to guide program growth