Frequency-domain streak camera for ultrafast imaging of evolving light-velocity objects

We demonstrate a frequency-domain streak camera (FDSC) that captures the picosecond time evolution of luminal-velocity refractive index structures in a single shot. In our prototype FDSC, a probe-reference pulse pair propagates obliquely to a subpicosecond pump pulse that creates an evolving nonlinear index structure in glass, supplementing a conventional frequency-domain holographic probe-reference pair that copropagates with the pump. A single spectrometer acquires data from both pairs via spatial or temporal multiplexing, demonstrating the feasibility of a compact frequency-domain tomographic system in which a single spectrometer processes data from multiple probing angles.

Identification of highly specific and cross-reactive antigens of Leishmania species by antibodies from Leishmania (Leishmania) chagasi naturally infected dogs

The Leishmania species present a genetic homology that ranges from 69 to 90%. Because of this homology, heterologous antigens have been used in the immunodiagnosis and vaccine development against Leishmania infections. In the current work, we describe the identification of species-specific and cross-reactive antigens among several New World Leishmania species, using symptomatic and asymptomatic naturally Leishmania chagasi-infected dog sera. Soluble antigens from five strains of New World Leishmania were separated by electrophoresis in SDS-PAGE and immunoblotted. Different proteins were uniquely recognized in the L. chagasi panel by either symptomatic or asymptomatic dog sera suggesting their use as markers for the progression of disease and diagnosis of the initial (sub-clinical) phase of the infection. Cross-reactive antigens were identified using heterologous antigenic panels (L. amazonensis strains PH8 and BH6, L. guyanensis and L. braziliensis). L. guyanensis panel showed the highest cross-reactivity against L. chagasi specific antibodies, suggesting that proteins from this extract might be suitable for the diagnosis of visceral canine leishmaniasis. Interestingly, the 51 and 97 kDa proteins of Leishmania were widely recognized (77.8% to 100%) among all antigenic panels tested, supporting their potential use for immunodiagnosis. Finally, we identified several leishmanial antigens that might be useful for routine diagnosis and seroepidemiological studies of the visceral canine leishmaniasis.

Accelerating monoenergetic protons from ultrathin foils by flat-top laser pulses in the directed-Coulomb-explosion regime

We consider the effect of laser beam shaping on proton acceleration in the interaction of a tightly focused pulse with ultrathin double-layer solid targets in the regime of directed Coulomb explosion. In this regime, the heavy ions of the front layer are forced by the laser to expand predominantly in the direction of the pulse propagation, forming a moving longitudinal charge separation electric field, thus increasing the effectiveness of acceleration of second-layer protons. The utilization of beam shaping, namely, the use of flat-top beams, leads to more efficient proton acceleration due to the increase of the longitudinal field.

Observation of synchrotron radiation from electrons accelerated in a petawatt-laser-generated plasma cavity

The dynamics of plasma electrons in the focus of a petawatt laser beam are studied via measurements of their x-ray synchrotron radiation. With increasing laser intensity, a forward directed beam of x rays extending to 50 keV is observed. The measured x rays are well described in the synchrotron asymptotic limit of electrons oscillating in a plasma channel. The critical energy of the measured synchrotron spectrum is found to scale as the Maxwellian temperature of the simultaneously measured electron spectra. At low laser intensity transverse oscillations are negligible as the electrons are predominantly accelerated axially by the laser generated wakefield. At high laser intensity, electrons are directly accelerated by the laser and enter a highly radiative regime with up to 5% of their energy converted into x rays.

Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes)

Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400-500 nauplii in less than 5 min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorption with peak body levels occurring within 1-2 h, then rapidly declining with elimination half-life of 0.3-3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h.

Influence of the nature of the antigen on the boosting of responses to mycobacteria in M. bovis-BCG vaccinated cattle

Mycobacterium bovis is the causative agent of bovine tuberculosis (TB) and of a proportion of human TB. Protection against TB requires Th1 responses and worsening of disease is associated with Th2 responses. To help clarify the nature of the response to mycobacteria, the responses from M. bovis-BCG vaccinated cattle boosted with live mycobacteria (BCG), bacterial soluble antigens (PPD) or PBS were evaluated. The results indicated that macrophages may be the major cell population ingesting and presenting mycobacteria in BCG boosted animals, while B-cells seem able to ingest and present PPD to T-cells in PPD boosted animals.

A First Look at Duloxetine (Cymbalta(R)) in a Postmortem Laboratory

Duloxetine (Cymbalta) is manufactured by Eli Lilly and Company and is the newest antidepressant to be approved by the Food and Drug Administration (FDA). Duloxetine is a potent serotonin and norepinephrine reuptake inhibitor that is also used for the management of pain associated with diabetic peripheral neuropathy. With the introduction of any new drug, toxicology laboratories around the nation experience the same problems: lack of information about the chemical and physical properties of the new drug, detection methodologies from biological specimens, and interpretation of quantitative values. Since its FDA approval in 2002, the Los Angeles County Department of Coroner Toxicology Laboratory has detected and quantitated duloxetine in 12 postmortem cases. The isolation of duloxetine from postmortem specimens consisted of a basic, liquid-liquid (n-butylchloride) extraction procedure. Duloxetine was detected in our general, pharmaceutical, basic drugs screen that utilizes gas chromatography-nitrogen-phosphorus detection (GC-NPD) and GC-mass spectrometry (MS), and the quantitation was specifically by GC-MS. Linearity was achieved from 0.05 to 3.0 mg/L with the limit of detection at 0.03 mg/L. Presented are the case histories, demographics, cause/manner of death, and the postmortem tissue distribution ranges of duloxetine: central blood, not detected (ND)-0.59 mg/L (12 cases); femoral blood, ND-0.26 mg/L (9 cases); vitreous humor, ND-0.23 mg/L (4 cases); liver, 0.28-22 mg/kg (8 cases); gastric contents, 0.08-86 mg total (6 cases); bile, 0.57-3.1 mg/L (7 cases); and urine, 0.07-0.47 mg/L (6 cases). The detection and quantitation of duloxetine in these 12 case studies are considered the first to be reported in the literature; all are designed to aid the forensic toxicologist with the interpretation of his/her own casework.

Evaluation of NOC Standardized Outcome of “Health Seeking Behavior” in Nurse-managed Clinics

This study evaluated the accomplishment of the Nursing Outcomes Classification (NOC) outcome "Health Seeking Behavior" in 5 nurse-managed clinics. Nurse practitioners and registered nurses rated patients on 11 indicators of health seeking behaviors, and recorded their level of knowledge of the patient. A total of 556 evaluations were collected. Health seeking behavior scores were lowest in a rural county school-based clinic and highest in a federally qualified health center. Ratings increased with nurses' knowledge of patients and for older patients.

Generation of 10(11) contrast 50 TW laser pulses

We demonstrate what we believe to be the highest-contrast (10(11)), multiterawatt, chirped-pulse amplification (CPA) Ti:sapphire laser by applying the modified cross-polarized-wave (XPW) generation method. This method produces a contrast improvement of 3 orders of magnitude using microjoule input energy. Microjoule energy can be achieved by direct amplification without the complications of a double CPA system. The 10(11) contrast is sufficient for experiments on high-damage-threshold solid targets with focused intensities up to 10(22) W/cm(2).

Generation of 10(11) contrast 50 TW laser pulses

We demonstrate what we believe to be the highest-contrast (10(11)), multiterawatt, chirped-pulse amplification (CPA) Ti:sapphire laser by applying the modified cross-polarized-wave (XPW) generation method. This method produces a contrast improvement of 3 orders of magnitude using microjoule input energy. Microjoule energy can be achieved by direct amplification without the complications of a double CPA system. The 10(11) contrast is sufficient for experiments on high-damage-threshold solid targets with focused intensities up to 10(22) W/cm(2).

Report of the equine herpesvirus-1 Havermeyer Workshop, San Gimignano, Tuscany, June 2004

Amongst the infectious diseases that threaten equine health, herpesviral infections remain a world wide cause of serious morbidity and mortality. Equine herpesvirus-1 infection is the most important pathogen, causing an array of disorders including epidemic respiratory disease abortion, neonatal foal death, myeloencephalopathy and chorioretinopathy. Despite intense scientific investigation, extensive use of vaccination, and established codes of practice for control of disease outbreaks, infection and disease remain common. While equine herpesvirus-1 infection remains a daunting challenge for immunoprophylaxis, many critical advances in equine immunology have resulted in studies of this virus, particularly related to MHC-restricted cytotoxicity in the horse. A workshop was convened in San Gimignano, Tuscany, Italy in June 2004, to bring together clinical and basic researchers in the field of equine herpesvirus-1 study to discuss the latest advances and future prospects for improving our understanding of these diseases, and equine immunity to herpesviral infection. This report highlights the new information that was the focus of this workshop, and is intended to summarize this material and identify the critical questions in the field.