Doctor of Physical Therapy Student Perceptions of Domestic Versus International Service-Learning Experiences: A Mixed-Methods Approach.

PURPOSE: The purpose of this study was to compare Doctor of Physical Therapy (DPT) students' perceptions of service-learning between domestic and international service-learning experiences (SLEs). METHODS: DPT students participated in semi-structured interviews (n=35) and completed the Service-Learning Benefit (SELEB) scale (n=21). Focus group questions targeted the impact of the SLE on topics related to PT services, social responsibility, cultural competence, and personal commitment to engaging in future service-related activities. The interviews were audio-recorded and transcribed. Incident coding processes analyzed transcripts of the focus groups. Differences in the students' perceptions of the benefit of SLEs using the SELEB were examined using Wilcoxon signed-rank test. RESULTS: Perceived advantages of an international SLE included improved relationship building, social responsibility, citizenship skills, cultural competence, gaining trust of others, and expansion of worldview. Perceived different benefits of the domestic SLE were planning and organizing the experience and improved commitment to the community. Additionally, students who participated in the international SLE cited more barriers (e.g., cost) than in the domestic SLEs. CONCLUSION: DPT students participating in domestic vs international SLEs appear to have different perceptions of SLE. Further research is needed to examine the perspective of other stakeholders involved in domestic and international SLEs.

Metals in tissues of seabass and seabream reared in sites with oxic and anoxic substrata and risk assessment for consumers.

Twenty-eight metals and elements were measured in the muscle, liver, gills, bone and intestine of farmed seabass and gilthead seabream from four Mediterranean fish farms. The influence of fish species and the effect of environmental conditions on the metal accumulation in fish tissues was investigated. Most concentrations were lower in muscle and higher in liver and bone than in other body tissues. Seabass accumulates more elements in its tissues than seabream. Fish reared in coarse, oxic sites accumulate more elements with higher concentrations in muscle, bone and intestine and with lower concentrations in liver and gills than fish reared in silty, anoxic sites. This may be attributed to feed type and sediment properties. According to the metal pollution index, hazard quotient, selenium health benefit values, carcinogenic risk of arsenic, maximum safe consumption and the permitted limits, the consumption of both farmed species should be considered as safe for human health.

Metals in benthic macrofauna and biogeochemical factors affecting their trophic transfer to wild fish around fish farm cages.

Benthic macroinvertebrates and wild fish aggregating in the vicinity of four Mediterranean fish farms were sampled. Concentrations of metals and other elements were measured in macrofaunal taxa and in fish tissues (muscle, liver, gills, bone, gonad, stomach, intestine, and stomach content). Biological and geochemical characteristics play an important role in metal accumulation in benthic invertebrates, and consequently in metal transfer to higher trophic levels. Macroinvertebrates accumulated lower concentrations of most metals and elements than their respective sediment, except As, P, Na, Zn and Cd. Elemental concentrations of benthic organisms increased with increasing sediment metal content, except Cd, and with % silt, refractory organic matter and chlorophyll-a of sediment due to the influence of sediment geochemistry on metal bioavailability. Tolerant species were found to accumulate higher concentrations of most metals and elements, except for Cd, than equilibrium species. The ecological and morphological characteristics of the benthic invertebrates can affect the bioaccumulation of metals and elements in macrobenthos. Hg and P were found to increase their concentrations from zoobenthos to wild fish aggregating around fish cages feeding on macrofauna.

Heavy metals, trace elements and sediment geochemistry at four Mediterranean fish farms.

Trace element concentrations in sediment were investigated at four fish farms in the Eastern Mediterranean Sea. Fish farms effects were negligible beyond 25-50 m from the edge of the cages. Based on elemental distribution, sediments from the farms were separated into coarse oxidized and silty reduced ones. Fish feed is richer in P, Zn and Cd than reference and impacted stations. Comparison among impacted stations and the respective reference stations shows that, in anoxic sediments, all elements had higher concentrations at the impacted stations than at reference stations while in oxic sediments, many elemental concentrations were lower at impacted stations than at reference stations. The behavior of elements and therefore their distribution is affected by changes in sediment grain size, organic content and redox regime. Elements in sediments around fish farms can be clustered into five groups according to these environmental variables. In silty and anoxic sediments, element concentrations were higher than in coarse and oxic ones. Several approaches were used to assess potential sediment toxicity (enrichment factors, geoaccumulation indices, contamination factors) as well as to assess the potential danger to aquatic life (Sediment Quality Guidelines, SQG). Cu, Zn and Fe can cause from threshold to extreme effects on aquatic life in anoxic, fine-grained sediments and As can cause threshold effects in all types of sediment around fish farms. Other elements (Cr, Pb, Mn) can also cause unwanted effects when compounded with elevated background levels.

Sea lice treatments on salmon farms have no adverse effects on zooplankton communities: a case study.

The long-term effects of the sea lice treatment products Excis and Slice on zooplankton communities in a Scottish sea loch were investigated at a commercially operating salmon farm over 31 months. Cypermethrin and emamectin benzoate are the active ingredients in Excis and Slice respectively, which are widely used to control ectoparasitic sea lice on farmed salmon. Excis and Slice treatments did not cause basin-wide effects on the zooplankton community. For both formulations, no adverse affects on zooplankton were detected, instead observed changes in zooplankton abundance and community composition displayed natural seasonal cycles of abundance. Water column concentrations of cypermethrin and emamectin benzoate following sea lice treatments at the fish farm were predicted using models. Cypermethrin concentrations of 3000 ng/l were predicted for short periods immediately after each cage treatment assuming no particle adhesion. The 3-h and 24-h Environmental Quality Standards (EQS) were exceeded for 10 h and 32 h respectively on the second day when five cages were treated. However, cypermethrin concentrations higher than 0.5 ng/l (24-h EQS) were predicted to occur over <2% of the total basin area on each treatment day. The 3-h EQS (16 ng/l) was exceeded in <0.3% of the basin on each treatment day. The concentration of soluble emamectin benzoate present in the water column was predicted from modelled deposition footprints and sediment concentrations to be of order 10(-3) ng/l. Predicted concentrations of both chemicals were generally lower than those causing toxicity to copepods in previous laboratory studies and further support the results of this field study that environmental concentrations of Excis and Slice do not adversely impact zooplankton communities.

Micellar electrokinetic chromatography of tri aza aromatic ligand compounds of iron (II): influence of bile salt type on enantiomeric separation.

Micellar electrokinetic chromatography is used with a variety of bile salt micelles to separate the enantiomers of bis(8-((pyridine-2-methylene)amino)quinoline)iron(II) hexafluorophosphate, Fe(PMAQ)2(PF6)2; bis(8-((pyridine-2-methylene)amino)lepidine iron(II) hexafluorophosphate, Fe(PMAL)2(PF6)2; and bis(1-(2-pyridinyl)ethylidine)-8-aminoquinoline iron(II) hexafluorophosphate, Fe(PEAQ)2(PF6)2. The influence of ten different bile salts on the resolution of each pair of enantiomers is investigated. Significant changes in resolution are seen depending upon the bile salt used. The dihydroxy bile salts are superior to the trihydroxy bile salts in terms of resolution, and the taurine or glycine conjugated bile salts yield better results than the unconjugated bile salts. Resolution for most enantiomers is maximized in a buffer solution containing 10-15% acetone and employing either taurochenodeoxycholic or glycochenodeoxycholic acid as the bile salt. Evidence for the separation of the corresponding Fe(III) complexes is presented.

Tetracaine reports a conformational change in the pore of cyclic nucleotide-gated channels.

Local anesthetics are a diverse group of clinically useful compounds that act as pore blockers of both voltage- and cyclic nucleotide-gated (CNG) ion channels. We used the local anesthetic tetracaine to probe the nature of the conformational change that occurs in the pore of CNG channels during the opening allosteric transition. When applied to the intracellular side of wild-type rod CNG channels expressed in Xenopus oocytes from the alpha subunit, the local anesthetic tetracaine exhibits state-dependent block, binding with much higher affinity to closed states than to open states. Here we show that neutralization of a glutamic acid in the conserved P region (E363G) eliminated this state dependence of tetracaine block. Tetracaine blocked E363G channels with the same effectiveness at high concentrations of cGMP, when the channel spent more time open, and at low concentrations of cGMP, when the channel spent more time closed. In addition, Ni2+, which promotes the opening allosteric transition, decreased the effectiveness of tetracaine block of wild-type but not E363G channels. Similar results were obtained in a chimeric CNG channel that exhibits a more favorable opening allosteric transition. These results suggest that E363 is accessible to internal tetracaine in the closed but not the open configuration of the pore and that the conformational change that accompanies channel opening includes a change in the conformation or accessibility of E363.

Prevention of recurrent fetal loss caused by antiphospholipid syndrome.

Repeated fetal loss presents a challenge for both patients and health care professionals. Antiphospholipid syndrome (APS) may account for as much as 10% to 48% of recurrent fetal loss. Suggested pathophysiologic mechanisms of APS in fetal loss include the action of autoantibodies, the lupus anticoagulant, and anticardiolipin antibodies on the endothelial cells, which may lead to platelet aggregation, thrombosis, placental infarcts, and subsequently reduced oxygenation to the fetus. This study explores fetal loss caused by APS, its pathophysiologic features, treatment, and nursing implications. Heparin therapy is presented as a method to prevent intrauterine growth retardation and fetal death. The educational and psychosocial needs of patients receiving this therapy and necessary patient follow-up and coordination of services are reviewed.

Friedel-Crafts alkylation of benzene and toluene with olefinic C6 hydrocarbons and esters.

To assist our study of the reaction of toluene and other aromatic compounds with methyl oleate and other olefinic esters, benzene and toluene have been alkylated under Friedel-Crafts conditions with hex-1-ene, hex-3-ene, methyl hex-3-enoate and methyl hex-3-enedioate. The products were isolated and identified by NMR and mass spectrometric procedures.

The Friedel-Crafts adducts of methyl oleate with benzene and toluene.

The Friedel-Crafts adducts of methyl oleate with benzene and toluene have been synthesized. The products are a mixture of monomer, dimer and trimer esters together with adducts containing one, two or three molecules of ester per mol of aromatic compound, depending on the proportions of starting material used. The 1H- and 13C-NMR spectra of the adducts are reported together with their mass spectra.

Molecular mechanism for ligand discrimination of cyclic nucleotide-gated channels.

Cyclic nucleotide-gated ion channels of retinal photoreceptors and olfactory neurons are differentially activated by ligands that vary only in their purine ring structure. The nucleotide selectivity of the bovine rod cyclic nucleotide-gated channel (cGMP > cIMP >> cAMP) was significantly altered by neutralization of a single aspartic acid residue in the binding domain (cGMP > or = cAMP > cIMP). Substitution by a nonpolar residue at this position inverted agonist selectivity (cAMP >> cIMP > or = cGMP). These effects resulted from an alteration in the relative ability of the agonists to promote the allosteric conformational change associated with channel activation, not from a modification in their initial binding affinity. We propose a general mechanism for guanine nucleotide discrimination, in common with that observed in high affinity GTP-binding proteins, involving the formation of a pair of hydrogen bonds between the aspartic acid side chain and N1 and N2 of the guanine ring.

Alterations in ankle dorsiflexion torque as a result of continuous ultrasound to the anterior tibial compartment.

Although considerable documentation of the physiologic effects of ultrasound (US) exists, little information is available concerning direct effects of US on muscle, particularly when the US is applied immediately before muscle performance. The purpose of this study was to determine the effect of continuous US to the anterior tibial muscle compartment on ankle dorsiflexion torque assessed immediately posttreatment, at 30 minutes, and at 60 minutes posttreatment. Seventeen healthy subjects were tested performing isometric contractions at dynamometer velocities of 60 and 180 degrees/sec. Subjects first received either a placebo or a 1.5 W/cm2 15-minute US treatment. One week later, the protocol was repeated with the administration of a second treatment. Analysis of variance showed no significant interactions for time and treatment for any contraction; time, for isometric contraction, was the only significant main effect. Follow-up analyses were all nonsignificant for comparisons of pretreatment to posttreatment and posttreatment to 30- and 60-minute intervals within treatment groups. The study concludes that in spite of known physiologic effects, one treatment of US does not have an immediate or latent effect on peak torque.