Short-Term Plasticity in a Computational Model of the Tail-Withdrawal Circuit in Aplysia.

The tail-withdrawal circuit of Aplysia provides a useful model system for investigating synaptic dynamics. Sensory neurons within the circuit manifest several forms of synaptic plasticity. Here, we developed a model of the circuit and investigated the ways in which depression (DEP) and potentiation (POT) contributed to information processing.

Osmium in environmental samples from Northeast Sweden. Part I. Evaluation of background status.

Osmium (Os) concentrations and (187)Os/(188)Os isotope abundance ratios are presented for sedimentary materials, soils, humus, plants, mushrooms, mosses and lichens collected in the vicinity of the town of Luleå, Northeast Sweden, the data for biological specimens being the first reported. Contributions from sampling and varying exposure time to the observed environmental variability were evaluated. Sedimentary materials (from both fresh and brackish water) are most elevated in radiogenic (187)Os, followed by inorganic soil horizons, mushrooms and humus.

Osmium in environmental samples from Northeast Sweden. Part II. Identification of anthropogenic sources.

Osmium (Os) concentrations and (187)Os/(188)Os isotope abundance ratios measured in epiphytic lichens from Northeast Sweden have been used for the identification of anthropogenic emission sources of this element. Based on isotope abundance ratios and similarities in spatial distributions between Os and chromium, smelters operated on chromium ores from Kemi deposits have shown to be the most important factor affecting the airborne Os burden in the region. The extent of the exposure is reflected by lichen concentrations near the source exceeding those from remote areas by a factor of 1000.

Evaluation of the influence of amino acid composition on the propensity for collision-induced dissociation of model peptides using molecular dynamics simulations.

The dynamical behavior of model peptides was evaluated with respect to their ability to form internal proton donor-acceptor pairs using molecular dynamics simulations. The proton donor-acceptor pairs are postulated to be prerequisites for peptide bond cleavage resulting in formation of b and y ions during low-energy collision-induced dissociation in tandem mass spectrometry (MS/MS). The simulations for the polyalanine pentamer Ala(5)H(+) were compared with experimental data from energy-resolved surface induced dissociation (SID) studies.

Self-assembled virus-like particles with magnetic cores.

Efficient encapsulation of functionalized spherical nanoparticles by viral protein cages was found to occur even if the nanoparticle is larger than the inner cavity of the native capsid. This result raises the intriguing possibility of reprogramming the self-assembly of viral structural proteins. The iron oxide nanotemplates used in this work are superparamagnetic, with a blocking temperature of about 250 K, making these virus-like particles interesting for applications such as magnetic resonance imaging and biomagnetic materials.

The development of expertise in pediatric rehabilitation therapists: changes in approach, self-knowledge, and use of enabling and customizing strategies.

Purpose: To examine the clinical decision making of novice, intermediate, and expert pediatric rehabilitation therapists from various disciplines.

Methods: Two qualitative studies were conducted. Thirteen therapists took part in a study using the critical incident interview technique and 11 therapists took part in a study using the 'think aloud' technique.

Laser safety in the operating room.

Lasers are a safe and effective tool when used appropriately with the proper safeguards in place. Institutions that use lasers must have safety protocols in place, as well as a Laser Safety Officer overseeing the implementation of these protocols.

Flexion mobilizations with movement techniques: the immediate effects on range of movement and pain in subjects with low back pain.

Objective: This study investigates the immediate effects of flexion mobilizations with movement techniques (MWMs) on spinal range of movement in individuals with low back pain and also their impact on pain. A preliminary attempt has been made to describe the clinical profiles of subjects who were thought to benefit from MWMs.

Method: A small-scale explanatory study was conducted using a crossover design, placebo-controlled, with subjects and assessors blinded.

Ion-specific isotopic fractionation of molybdenum during diffusion in aqueous solutions.

Experiments modeling diffusion of Mo in aqueous solutions have been performed and, using multicollector ICP-MS, the ratios of the diffusivities of Mo isotopes, D97Mo/ D95Mo, in aqueous solutions have been determined. Diffusion of MoO42- ions in solution was concomitant with Mo isotopic fractionation with D97Md/D95Mo = 0.99988+/-0.

Authentication of Kalix (N.E. Sweden) vendace caviar using inductively coupled plasma-based analytical techniques: evaluation of different approaches.

Different analytical approaches for origin differentiation between vendace and whitefish caviars from brackish- and freshwaters were tested using inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). These approaches involve identifying differences in elemental concentrations or sample-specific isotopic composition (Sr and Os) variations. Concentrations of 72 elements were determined by ICP-SFMS following microwave-assisted digestion in vendace and whitefish caviar samples from Sweden (from both brackish and freshwater), Finland and USA, as well as in unprocessed vendace roe and salt used in caviar production.

Is the prevalence of wheeze in children altered by neonatal BCG vaccination?

Background: The prevalence of asthma and atopic disease has increased in recent decades, but precise reasons for this increase are unknown. BCG vaccination is thought to be among a group of vaccines capable of manipulating the immune system toward T(H)1 dominance and therefore reducing the likelihood of atopic disease.

Objective: The aim of this study was to determine the influence of neonatal BCG vaccination on the prevalence of wheeze in a large community population of children.

Clinical importance of the lateral branch of the deep peroneal nerve.

Persistent recalcitrant dorsolateral foot pain after ankle sprain cannot always be explained by known anatomic nerve pathways. To determine whether an impingement of a lateral branch of the deep peroneal nerve might be responsible for atypical pain, we conducted a cadaveric anatomic study to identify the anatomy and course of the nerve. Furthermore, using this information, we conducted a clinical study to determine if targeted treatment to a lateral branch of the deep peroneal nerve would resolve these symptoms.

Anesthetic care of the trauma patient: development of a Web-based resource.

Adequate preparation by anesthesia providers promotes quality care and decreases the likelihood of morbidity and mortality. Unfortunately, many trauma cases occur after hours when support resources are less readily available. At a large midwest academic medical center, it was determined that a website on the institution's Intranet relating to anesthetic care of trauma patients would be a readily accessible, user-friendly resource for improved care.

Dynamics of a minimal model of interlocked positive and negative feedback loops of transcriptional regulation by cAMP-response element binding proteins.

cAMP-response element binding (CREB) proteins are involved in transcriptional regulation in a number of cellular processes (e.g., neural plasticity and circadian rhythms).

Feeding behavior of Aplysia: a model system for comparing cellular mechanisms of classical and operant conditioning.

Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural circuitry that mediates the behavior is well characterized and amenable to detailed cellular analyses, substantial progress has been made toward a comparative analysis of the cellular mechanisms underlying these two forms of associative learning.

Methylmercury measurement in whole blood by isotope-dilution GC-ICPMS with 2 sample preparation methods.

Background: Despite its known toxicity, methylmercury is rarely measured directly in clinical studies; instead, conclusions are based on total mercury measurements. We have developed isotope-dilution-based methods for methylmercury-specific analysis of whole blood by coupled gas chromatography-inductively coupled plasma mass spectrometry (GC-ICPMS).

Methods: We analyzed animal and human blood samples after alkaline digestion or extraction of methylmercury into dichloromethane and back extraction into water.

Efficacy of transcutaneous electrical nerve stimulation (tens) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial.

Objective: This study was designed to investigate the hypoalgesic effects of self-applied transcutaneous electrical nerve stimulation (TENS) on chronic low-back pain (LBP) in a multiple sclerosis (MS) population.

Methods: Ninety participants with probable or definite MS (aged 21 to 78 y) presenting with chronic LBP were recruited and randomized into 3 groups (n=30 per group): (1) low-frequency TENS group (4 Hz, 200 micros); (2) high-frequency TENS group (110 Hz, 200 micros); and (3) placebo TENS. Participants self-applied TENS for 45 minutes, a minimum of twice daily, for 6 weeks.

Major histocompatibility complex class II (DR) antigen and costimulatory molecules on in vitro and in vivo activated human polymorphonuclear neutrophils.

We have previously shown that normal human peripheral blood polymorphonuclear neutrophils (PMNs) contain cytoplasmic 'stores' of three key molecules normally associated with antigen presentation and T-cell costimulation, i.e. major histocompatibility complex class II (DR) antigen, CD80 (B7-1) and CD86 (B7-2).

Benchmarking performance in organ donation programs: dependence on demographics and mortality rates.

Purpose: Donors whose diagnosis of death is based upon neurologic criteria are the primary source of organs for human transplantation. The current measure of effectiveness of organ donation programs is the crude statistic, donors per million population (DPMP). This statistic represents the number of available donors, divided by the potential donor population.

Gait outcome following outpatient physiotherapy based on the Bobath concept in people post stroke.

Purpose: The purpose of this study was to characterize the gait cycle of patients with hemiplegia before and after a period of outpatient physiotherapy based on the Bobath concept.

Methods: Nine patients, at least 6 weeks post stroke and recently discharged from a stroke unit, were measured before and after a period of outpatient physiotherapy (mean duration = 17.4 weeks).

Role of A-type K+ channels in spike broadening observed in soma and axon of Hermissenda type-B photoreceptors: a simulation study.

In Hermissenda type-B photoreceptors, the spike is generated in the axon and back-propagated to the soma, resulting in smaller somatic spikes. Experimentally, blocking the A-type K+ current (IK,A) results in broadening of somatic spikes. Similarly, in a compartmental model of the photoreceptor, reducing the maximum A-type K+ conductance (gK,Amax) results in broadening of somatic spikes.

Social behavior and meningococcal carriage in British teenagers.

Understanding predisposing factors for meningococcal carriage may identify targets for public health interventions. Before mass vaccination with meningococcal group C conjugate vaccine began in autumn 1999, we took pharyngeal swabs from approximately 14,000 UK teenagers and collected information on potential risk factors. Neisseria meningitidis was cultured from 2,319 (16.

A qualitative investigation of changes in the belief systems of families of children with autism or Down syndrome.

Background: There have been few reports of the world views, values and priorities of families of children with autism or Down syndrome, despite the fact that family belief systems are considered to be among the most important factors affecting the adaptation and resilience of families.

Methods: Transcripts from three focus groups involving 19 key informants (15 parents of children with autism or Down syndrome, and 4 service providers) were analysed using qualitative methods.

Results: The themes indicated that raising a child with a disability can be a life-changing experience that spurs families to examine their belief systems.