Prevalence of Sexually Transmitted Infections Among Adolescents Entering Child Protective Services.

STUDY OBJECTIVE: Persons aged 15-24 years have the highest rates of sexually transmitted infections (STIs). Adolescents in protective services custody may be at even greater risk of acquiring STIs, but little is known about the prevalence of STIs among this population. We therefore set out to assess the prevalence of STIs among adolescents seen in the Harris County Child Protective Services Clinic. DESIGN: A retrospective chart review from January 2009 to December 2011 was conducted. SETTING AND PARTICIPANTS: Patients aged 12-18 years seen for their intake physical examination at the Harris County Child Protective Services Clinic in Houston, Texas. MAIN OUTCOME MEASURES: Main outcome measures included the number of positive tests for chlamydia, gonorrhea, syphilis, and HIV. Secondary measures included sexual history, use of condoms and contraception, and reports of drug and alcohol use. RESULTS: Among 437 patients, 60% were female, their mean age was 15 years, and nearly half were African American. There were 27 cases of chlamydia, 12 of gonorrhea, 3 of syphilis, and none of HIV. Three of the teenagers who reported never having sex were positive for an STI. Being female, being older than 15 years, and having had sexual intercourse at least once were significant risk factors. CONCLUSION: The prevalence of STIs in adolescents entering foster care was comparable to national averages. Recommending routine screening of all adolescents in this population is important to ensure better detection and treatment.

Manipulating supercontinuum generation by minute continuous wave.

We report a simple triggering mechanism that greatly enhances and stabilizes supercontinuum generation by using an extremely weak cw light (~200,000 times weaker than the pump light). Such an active manipulation scheme can be enabled by a wide range of input conditions and circumvents complex techniques such as precise time delay tuning and dedicated feedback control. It thus offers a handy and versatile approach to control and optimize supercontinuum generation, expanding its range of applications, including ultrafast all-optical signal processing, spectroscopy, and imaging. The utility of the present technique for improving signal integrity in chirped pump optical parametric amplification is also demonstrated.

Fast and wide tuning wavelength-swept source based on dispersion-tuned fiber optical parametric oscillator.

We demonstrate a dispersion-tuned fiber optical parametric oscillator (FOPO)-based swept source with a sweep rate of 40 kHz and a wavelength tuning range of 109 nm around 1550 nm. The cumulative speed exceeds 4,000,000 nm/s. The FOPO is pumped by a sinusoidally modulated pump, which is driven by a clock sweeping linearly from 1 to 1.0006 GHz. A spool of dispersion-compensating fiber is added inside the cavity to perform dispersion tuning. The instantaneous linewidth is 0.8 nm without the use of any wavelength selective element inside the cavity. 1 GHz pulses with pulse width of 150 ps are generated.

Tunable single-longitudinal-mode fiber optical parametric oscillator.

A tunable single-longitudinal-mode (SLM) fiber optical parametric oscillator (FOPO) is proposed and demonstrated experimentally. A sub-ring cavity with a short cavity length is used to suppress the longitudinal modes and broaden the longitudinal mode spacing. A fiber loop mirror, consisted of an unpumped erbium-doped fiber, acts as an autotracking filter for providing fine mode restriction and ensuring the single-frequency operation. The measurement based on a homodyne method shows that the FOPO provides the SLM output. Furthermore the SLM FOPO can be tunable over 14 nm for each of the signal and the idler, which is limited only by the gain bandwidth of the fiber optical parametric amplifier.

Widely tunable picosecond optical parametric oscillator using highly nonlinear fiber.

We demonstrated a fully fiber-integrated widely tunable picosecond optical parametric oscillator based on highly nonlinear fiber. The ring cavity with a 50 m highly nonlinear fiber was synchronously pumped with a picosecond mode-locked fiber laser. The tuning range was from 1413 to 1543 nm and from 1573 to 1695 nm, which was as wide as 250 nm. A high-quality pulse was generated with a pulse width narrower than that of the pump.