Mach-Zehnder interferometer comb filter for multi-wavelength mode-locked generation from erbium-doped fiber laser.

A picosecond pulse multi-wavelength erbium-doped fiber ring laser based on an optically switchable/tunable Mach-Zehnder interferometer (MZI) filter is proposed and experimentally demonstrated. The MZI configuration is constructed with two 3 dB couplers and two short pieces of endlessly single-mode photonic crystal fiber with different lengths in each arm. The combination of the MZI and a polarization controller (PC) acts as a selective comb filter and a mode-locking device. By adjusting the pump power or the first PC (PC1) state, the laser can emit up to 10 channels with a 20 nm tuning range (1530 to 1550 nm). Furthermore, by changing the PC1 condition, stable picosecond mode-locking generation with a repetition rate of 13.5 MHz is realized. To achieve wavelength spacing tunable multiple-channel laser emissions, the MZI is configured by incorporating a second PC (PC2) in one arm of the conventional MZI. Four channels of picosecond mode-locking pulses with a repetition rate of 11.6 MHz in the range of 1530-1550 nm are realized by carefully controlling the pump power and/or PC2 state. With the manipulation of intracavity birefringence through PCs with comb filtering via MZI, the proposed structure may be a potential tool in various photonics applications.

Race/ethnicity differences in response to acute antihypertensive treatment of peripartum severe hypertension.

BACKGROUND: Hypertensive disorders of pregnancy increase maternal morbidity, mortality, and long-term risk for cardiovascular disease. The rising incidence of chronic hypertension and preeclampsia disproportionately affects people of color. There is a paucity of published data examining differences in the effectiveness of acute antihypertensive agents between pregnant patients of different races/ethnicities. We aimed to determine if the effectiveness of acute antihypertensive agents for peripartum severe hypertension differs by race/ethnicity. METHODS: A retrospective cohort study of patients with severe peripartum hypertension (systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 110 mm Hg confirmed within 15 min) to determine whether the effectiveness of blood pressure control using nationally recommended medications (hydralazine, labetalol, nifedipine) differed by race/ethnicity. The primary outcome was reduction and maintenance of blood pressure to target ranges (140-150/90-100 mm Hg or below) for ≥4 h in each race/ethnicity group. Statistical tests included χ2, Fisher's exact, analysis of variance, and multivariable logistic regression. RESULTS: Of 729 patients receiving treatment for severe peripartum hypertension, all medications were effective (overall 86.4% efficacy) at controlling blood pressure. Labetalol was the most effective medication in White patients (93.0 vs. 74.7% for nifedipine and 86.5% for hydralazine, p < .001). No overall differences in medication effectiveness were found in Black, Asian, or LatinX patients. Black and Asian patients were more likely to experience >1 hypertensive episode [51.0 and 49.0%, respectively vs. 35.4% (White) and 40.0% (LatinX), p = .008]. CONCLUSION: Currently recommended therapies for severe peripartum hypertension are effective in controlling blood pressure for ≥4 h in patients of all race/ethnic groups. Labetalol was the most effective medication in White patients with no overall differences in medication effectiveness in Black, Asian, or LatinX patients.

Antifouling properties of amphiphilic poly(3-hydroxyalkanoate): an environmentally-friendly coating.

The development of biofouling is a major problem for marine industries. The conception of antifouling and fouling release coatings, with controlled physical-chemical properties is a promising strategy. Among them, amphiphilic systems, such as those composed of a hydrophobic polydimethylsiloxane matrix and a hydrophilic polyethyleneglycol additive are the most efficient and up to date. Despite their effectiveness, these systems are questioned due to the petrochemical origin of PDMS. The aim of this project was to substitute the PDMS matrix with a biopolymer, poly(3-hydroxybuyrate-co-3-hydroxyvalerate) and to improve its anti-adhesion properties through the elaboration of an amphiphilic system, via the addition of PEG or PHBHHx-b-PEG copolymer. The results, including the physico-chemical properties of PHBHV based coatings and static adhesion tests on a marine bacterium, Bacillus 4J6 and a diatom, Phaeodactylum tricornutum are compared with those of PDMS and PEG-modified PDMS coatings. Real antiadhesion activity was obtained for the PHBHV/PHBHHx-b-PEG system for a promising eco-friendly strategy.

Reverse transcriptase and protease inhibitors mutational viral load in HIV infected pregnant women with transmitted drug resistance in Argentina.

OBJECTIVE: Argentina has reported high levels of transmitted drug resistance (TDR), in HIV-infected pregnant women by population sequencing. We aimed to describe, in patients with TDR, the percentage of quasispecies harboring resistance mutations (RAMs) and mutational load (ML). METHODS: Retrospective study in a cohort of 40 naïve HIV-infected pregnant women, whose pretreatment samples had been genotyped by TRUGENE (period 2008-2014). Samples were re-sequenced with Ultra-deep Sequencing and ML was calculated considering baseline HIV-1 RNA load multiplied by the frequency of quasispecies harboring RAMs. RESULTS: TDR for NNRTIs, NRTIs and PIs was 17.5% (n=7 patients), 10% (n=4), 12.5% (n=5) respectively. Predominant NNRTI RAMs were K103N (n=4; 10%) and G190A/E/S (n=3; 7.5%). For NNRTIs, 78% of RAMs were present in >93.5% of viral population and ML was >1000 copies/mL (c/mL) for 89%, with a median (IQR) of 8330 c/ml (7738-29796). The following NRTI RAMs were described (per patient: % of quasispecies, ML): T215I (99.7%, 11014 c/ml); D67G (1.28%, 502 c/mL); M41L (79.8%, 88578 c/mL) and M184I (1.02%, 173 c/mL). Most frequent PI-RAMs were I85V, M46I, I50V and L90M (n=2, 5% each). For PIs, quasispecies with RAMs were <2.3% of viral population and ML was <350 c/mL for 77.8% of them. CONCLUSIONS: NNRTI-RAMs are predominant within the viral population, usually exceeding the threshold of 1000 c/mL, indicating potential higher risk of perinatal transmission. Conversely, PI mutations appear mostly as minority variants, with potential lower risk of transmission. Among NRTI, quasispecies harboring RAMs and ML values were variable.

Stable evanescent wave mode-locked laser based on a photonic-crystal-fiber-induced Mach-Zehnder filter as a gain-tilt equalizer.

In this paper, a switchable multichannel ytterbium-doped fiber laser based on a Mach-Zehnder interferometer (MZI) has been experimentally demonstrated. The MZI is fabricated by splicing a short piece of nonlinear photonic-crystal fiber (NLPCF) between two segments of a single-mode fiber. MZI-based NLPCF gathering with the intracavity birefringence polarization controller offers functions as both the selective comb filter and the mode locker. The laser can emit a single, dual, triple, or quadruple channel that can be varied in the spectral span around1030-1050 nm by only adjusting the pump power or polarization state. A stable evanescent wave, picosecond mode-locking generation with variable repetition rate (24.5 to 18.23 MHz and 34.64 MHz) has been realized via only inserting the polarization controller and adjusting its state inside the cavity. To the best of the authors' knowledge, this the first demonstration of a passive filter based on a NLPCF-MZ interferometer to generate switchable mode-locked pulses delivered from a single laser oscillator.

[Cystatin C: Biomarker of cardiovascular risk in HIV]. / Cistatina C: Biomarcador de riesgo cardiovascular en VIH.

INTRODUCTION: Patients infected with the human immunodeficiency virus (HIV) have a higher cardiovascular risk (CVR). The development of cardiovascular disease (CVD) in this population involves traditional CVR factors and factors related to the infection itself, such as chronic inflammatory status, immune dysfunction, as well as the antiretroviral therapy received. Cystatin C (CC) has shown to be useful in assessing the presence of CVR factors and CVD established in the general population, the elderly population, and patients with chronic kidney disease. An analysis was performed on this association in an HIV positive population (HIV+). MATERIAL AND METHODS: Analytical, observational, cross-sectional study was conducted, and included collecting information about CVR factors and CVD in HIV+, as well as measuring CC. The patients were divided into 2 groups: Group1=high CC (≥0.95mg/L) and Group2=normal CC (<0.95mg/L). RESULTS: A total of 95 patients were included. Group1=27 (28.4%) and Group2=68 (71.5%). A value of CC≥0.95mg/L was related to the presence of CVD (P=.01). It was also related with and an increase in waist circumference (P=.05), neck circumference (P=.04), systolic blood pressure (P=.04), diastolic blood pressure (P=.01), Framingham score (P=.03), and Framingham score adapted for HIV (P=.01). After performing multivariate analysis with incorporation of variables associated with CVD in the bivariate analysis, only CC≥0.95mg/L continued to be related to CVD. CONCLUSION: CC≥0.95mg/L was independently associated with CVD. This cut-off point was also linked to higher levels of blood pressure, and higher CVR at 10 years using the Framingham Score and Framingham Score adapted for HIV population.

The relationship of prenatal maternal depression or anxiety to maternal caregiving behavior and infant behavior self-regulation during infant heel lance: an ethological time-based study of behavior.

BACKGROUND: Sensitive and responsive maternal caregiving behavior strengthens infant self-regulatory capacities (HL), but this regulatory role may be diminished in some mothers with second-trimester prenatal exposure to depression and/ or anxiety (MDA). This study examined maternal and infant behavior during infant heel lance (HL) when mothers had or did not have MDA. Ethological methods and micro-analytic approaches capable of distinguishing and comparing time-based patterning in maternal and infant behavior were used to clarify biological mechanisms, such as MDA, that may underlie observed behavior. Aims were to examine group differences in caregiving behavior between mothers with and without MDA 5 min Pre-HL and 5 min Post-H, and relationships between MDA, maternal caregiving behavior and infant pain behavior self-regulation, concurrently. METHODS: At second trimester, mothers were assessed for symptoms of mild-severe depression or anxiety. Mothers whose scores exceeded predetermined cut-off scores on one or more of the mental health measures were allocated to the MDA-exposure group, those below to the non-MDA-exposure group. Reliable observers, blinded to MDA status and study phases, coded video records of the caregiving behavior of each study mother for the full duration of the 5 min Pre-HL and 5 min Post-HL study phases. Group differences and associations between mean measures of maternal mental health scores, time-based measures of maternal behavior, and time-based measures of infant pain behavior regulation (previously coded) were concurrently analyzed using comparative and correlational statistics. RESULTS: MDA-exposed mothers spent significantly more time not embracing, engaging or responding to infant cues than maternal controls Pre-HL and Post-HL. MDA was associated with atypical maternal caregiving behavior, which in turn was related to atypical infant pain behavior self-regulation during and after the HL. CONCLUSION: Our findings have implication for practice. We recommend inclusion of mothers with MDA and their infants in interventions that strengthen the early mother-infant interaction and mother's regulatory caregiving role. MDA and maternal caregiving behavior must be considered in future infant pain studies to examine if they confound effectiveness of mother driven caregiving interventions for neonatal pain. We highlight the importance of examining maternal mental health throughout the perinatal and postnatal trajectory, and particularly the newborn period.

Prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients.

Hypersensitivity reaction to abacavir (ABC hypersensitivity syndrome, AHS) is strongly associated with the presence of the HLA-B*57:01 allele. This study was designed to estimate the prevalence of HLA-B*57:01 allele in Argentinean HIV-1 infected patients. We analyzed the presence of HLA-B*57:01 allele in 1646 HIV-1 infected patients from different regions of Argentina. This allele was detected in 81 patients; most of them corresponded to patients living in the central region of the country. The prevalence of HLA-B*57:01 was 4.9%, similar to other Caucasian populations and higher than other data reported for South American populations. This strongly supports screening for the presence of HLA-B*57:01 in abacavir treatment of HIV-1 in our country.

Nanoencapsulation of ABT-737 and camptothecin enhances their clinical potential through synergistic antitumor effects and reduction of systemic toxicity.

The simultaneous delivery of multiple cancer drugs in combination therapies to achieve optimal therapeutic effects in patients can be challenging. This study investigated whether co-encapsulation of the BH3-mimetic ABT-737 and the topoisomerase I inhibitor camptothecin (CPT) in PEGylated polymeric nanoparticles (NPs) was a viable strategy for overcoming their clinical limitations and to deliver both compounds at optimal ratios. We found that thrombocytopenia induced by exposure to ABT-737 was diminished through its encapsulation in NPs. Similarly, CPT-associated leukopenia and gastrointestinal toxicity were reduced compared with the administration of free CPT. In addition to the reduction of dose-limiting side effects, the co-encapsulation of both anticancer compounds in a single NP produced synergistic induction of apoptosis in both in vitro and in vivo colorectal cancer models. This strategy may widen the therapeutic window of these and other drugs and may enhance the clinical efficacy of synergistic drug combinations.

Alteration of bacterial adhesion induced by the substrate stiffness.

The aim of this paper is to study the impact of the substrate stiffness on the bacterial adhesion. For this purpose, agarose hydrogels are used as substrates with controlled mechanical properties. Indeed, the elastic modulus of these hydrogels, more precisely the shear storage moduli G', evolves with the agarose concentration (in this study from 0.75% to 3%). Other physico-chemical characteristics of the surface, known to be involved in bacterial adhesion, as hydrophobicity, were confirmed to remain constant. Two marine bacterial strains, a positive Gram Bacillus sp. 4J6 and a negative Gram Pseudoalteromonas sp. D41 were selected. Their retention on the substrates was analysed by confocal laser scanning microscopy and by counting of viable adhered bacteria. It was demonstrated that surface elastic modulus correlated with bacterial retention. Bacteria D41 adhered in higher numbers to rigid surfaces. For 4J6, bacterial adhesion patterns were changed: clusterings were observed on surfaces with lower elastic modulus. Furthermore, a proteomic study, based on the total soluble proteome of D41 strain, highlights an impact of elastic modulus on proteins synthesis. These data demonstrated an adapted response of adhering bacteria on hydrogels of varying mechanical properties.

Self-regulation (recovery) from pain: association between time-based measures of infant pain behavior and prenatal exposure to maternal depression and anxiety.

OBJECTIVES: Capacities for self-regulation that influence infant adaptation to noxious stimulation require investigation of changes in behavior over time. Prenatal exposure to maternal depression and anxiety (MDA) has been linked to altered infant pain reactivity; however, findings are inconclusive about MDA dynamic impacts on recovery. This study quantified the temporal profile of behavioral response and recovery to routine heel lance (HL) of infants with and without prenatal-MDA exposure. Aims were to examine whether MDA were associated with alterations in time-based measures of infant behavior and sequential patterning in pain expression. MATERIALS AND METHODS: Videotaped facial, body, and cry behaviors of 21 full-term newborns were coded second-by-second for the duration of HL (baseline, HL, Post-HL) using validated behavioral coding systems. Mean heart rate and proportion of time infants spent exhibiting behavioral measures were compared between infant groups and over subphases of HL. Simple regressions, latency, and Yule-Q measures of effect size examined which behaviors were predicted by prenatal-MDA and magnitude of sequential association between first and subsequent behavior. RESULTS: During HL, all infants reacted immediately and substantially on heart rate, facial, body, and cry measures. Facial reactivity was followed within 2 seconds by body and cry behavior. There were no group differences in magnitude of initial behavioral reactions, but during Post-HL, MDA-exposed infants spent more time crying in a weak/exhausted manner and displayed strained and erratic limb movement and immobility. CONCLUSIONS: Temporal measures can further help in understanding of infant complex behavioral responses to pain. Delayed recovery in MDA-exposed infants suggested diminished capacities for self-regulation of noxious distress.

Early educational and behavioral RCT interventions to reduce maternal symptoms of psychological trauma following preterm birth: a systematic review.

Early behavioral and educational interventions have been developed to reduce maternal symptoms of psychological trauma (depression, anxiety, parenting stress, acute stress disorder, and posttraumatic stress disorder) following preterm birth (PTB). Aims of this systematic review were to critically assess study methodology and provide a synthesis of existing randomized control trial (RCT) interventions and to estimate effects of the interventions in reducing the maternal symptoms across studies. Four electronic databases were systematically searched to locate relevant RCTs using preestablished eligibility criteria. Data from 8 qualifying RCTs were synthesized. Two reviewers independently assessed study methodology using appraisal checklists. Considerable heterogeneity precluded calculation of pooled estimates. There is evidence that mothers of very preterm infants of low-birth-weight experience major depression for up to 12 months following PTB. Sound interventions implemented during and following infant hospitalization and grounded in coping and self-regulation had a small to moderate effect in reducing maternal depression and anxiety and parenting stress for up to 2 months and 12 months respectively. Clinicians can use existing evidence to help guide best practices. Future high-quality RCTs and meta-analysis require that researchers improve study methodology and include analysis of data on maternal hormonal stress and history of psychological symptoms including during the pregnancy.

A comparison of cesarean delivery outcomes for rural family physicians and obstetricians.

PURPOSE: Despite declining access to obstetrical care in many regions, family physicians often have difficulty obtaining Cesarean delivery privileges. We compared outcomes of Cesarean deliveries performed by family physicians (FPs) and obstetricians (OBs). The last such study done was more than 15 years ago. METHODS: This study was a chart review of 250 consecutive Cesarean deliveries was done at 2 rural New England hospitals. At one hospital, Cesarean deliveries were performed by FPs; at the other they were done by OBs. Demographics, pregnancy risk factors, and maternal and neonatal complication rates at each site were compared. RESULTS: Demographics, indications for Cesarean delivery, and prenatal risk factors were comparable at both sites except there were more hypertensive patients at the FP site. There were no differences in intraoperative or infectious complications. There were fewer postoperative complications at the FP hospital, which were mostly attributable to fewer blood transfusions and readmissions. There were no differences in neonatal outcomes, although there were more deliveries of fetuses <38 weeks' gestation at the FP site. CONCLUSIONS: Patients did not face increased risk when Cesarean deliveries were performed by FPs rather than OBs. A larger, more geographically diverse study is needed to confirm these findings. Results could support FPs seeking privileges to perform Cesarean deliveries, thus expanding access to care for pregnant women.

Long-term monitoring drug resistance by ultra-deep pyrosequencing in a chronic hepatitis B virus (HBV)-infected patient exposed to several unsuccessful therapy schemes.

The aim of this study was to analyze the spectrum and dynamics of low-prevalent HBV mutations in the reverse transcriptase (rt) and S antigen by ultra-deep pyrosequencing (UDPS). Samples were obtained from a chronically infected patient who was followed throughout a thirteen-year period. This technology enabled simultaneous analysis of 4084 clonally amplified fragments from the patient allowing detecting low prevalent (<1%) mutations during the follow-up. At baseline, HBV sequences were predominately wild-type. Under sequential HBV monotherapies including lamivudine, adefovir and entecavir, a high frequency of rtM204I mutation was detected initially as unique and then coexisting with rtM204V. Both mutations were statistically associated with rtA200V and rtV207I, respectively. Once the entecavir and tenofovir combined therapy was started, polymerase and consequently envelope gene mutations appeared at several positions at a higher frequency than before, including the entecavir resistance-associated mutation rtT184L.

Post-conflict transition and sustainability in Kosovo: establishing primary healthcare-based antenatal care.

INTRODUCTION: Kosovo is a post-conflict nation with an extensively damaged infrastructure, a weak primary care base, and poor maternal-child health outcomes. The Kosovo-Dartmouth Alliance for Healthy Newborns (the Alliance) sought to improve maternal and neonatal health in Kosovo by providing family medicine-based antenatal care (ANC). METHODS: The ANC Program used a modification of the World Health Organization's four-visit, prenatal care model. The program is based in family medicine and requires minimal medical equipment, such as a blood pressure cuff, fetal doppler, measuring tape, urine dipstick, and charting materials. Patient education and counseling are stressed. Women are taught about danger signs in pregnancy and establishing an emergency plan, so that they can respond promptly if complications occur. Antenatal care doctors and nurses are trained to refer women to obstetricians for deviations from normal pregnancy. The providers are taught using a "Training of Trainers" approach, building on an existing system of family medicine trainers. In order to address challenges in implementation and sustainability, microsystems methodology is used to focus on implementing change and assuring quality improvement through shared decision-making and the study of outcomes. RESULTS: Based on chart reviews and direct observation, ANC providers showed mastery of the components of ANC, including physical examination, recognition and referral of high-risk pregnancies, and patient education. After an initial pilot project, Kosovo's Ministry of Health recommended this program for dissemination throughout the country. During the next year, ANC was implemented at 27 Family Medicine Centers in nine municipalities; 1,671 women were seen for a total of 3,399 visits. Currently, the Alliance's model of ANC is offered in 30% of Kosovo's municipalities. DISCUSSION: International aid projects often lack attention to long-term sustainability. Microsystems training gives participants the tools and framework to implement and sustain change, even after international support is withdrawn. CONCLUSIONS: The Alliance's model of family medicine-based ANC is simple to teach and emphasizes sustainability. It may be modified for use in different cultures and healthcare systems and offers the opportunity to improve maternal and infant health by providing low cost antenatal care, available in a woman's own community.

Brief report: Maternal kangaroo care for neonatal pain relief: a systematic narrative review.

OBJECTIVE: To appraise critically and to synthesize existing Maternal Kangaroo Care (MKC) intervention studies for neonatal procedural pain. METHODS: Four electronic databases were systematically searched and eligible studies selected by two independent reviewers. Of 93 abstracts, 12 studies met the inclusion criteria. Findings were extracted and methodology assessed based on best-synthesis methodology. RESULTS: There is evidence that MKC can significantly reduce pain from a single pain procedure in full-term infants and stable preterm infants (>26 weeks GA). All 12 MKC studies reported significant reduction in pain behavior but measures of heart rate varied. However, current approaches to data analysis cannot tell us of the magnitude of treatment effects. CONCLUSIONS: Future studies need to clearly define their intervention, provide a guiding framework, explain their study methods and analyses and report effect sizes. This will help strengthen validity of the intervention and support recommendations for clinical application.

Caregiving behavior and interactions of prenatally depressed mothers (antidepressant-treated and non-antidepressant-treated) during newborn acute pain.

This exploratory study aimed to examine time-based measures of the behaviors and interactions of prenatally depressed serotonin reuptake inhibitors (SRI)-medicated mothers to their infant's pain (n = 10) by comparing them with similar measures obtained from prenatally depressed nonmedicated mothers and their infants (n = 10), and nondepressed mothers and their infants (n = 10). During the second trimester of their pregnancy, the 30 study mothers were assessed for depression and anxiety, with no further measures of maternal mood taken. Maternal and infant interactions were continuously videorecorded while the infant underwent a scheduled heel lance for routine blood screening that occurred when study infants were between the ages of 24 and 60 hr. Maternal behavior and infant cry, for all 30 cases, were coded second-by-second for the full duration of each infant's heel lance using a reliable coding system and analyzed using odds ratio and regression analyses. Infants exposed to prenatal SRIs and depressed maternal mood were more likely to have lower Apgar scores and to exhibit weak and absent cry. Even when duration of the heel lance was controlled for, women with depression during the second trimester were more likely to exhibit depressed behavior at 2 days' postpartum despite sustained SRI antidepressant treatment. Both groups of prenatally depressed mothers were more likely to exhibit diminished response to their infants' pain cue although nonmedicated mothers' expressions of depressed behavior were more similar to healthy controls. Comprehensive understanding is essential to optimize the clinical care of mothers and their infants in this complex setting. This study contributes preliminary new findings that warrant prospective and longitudinal studies to clarify further the impacts of prenatal SRI and maternal mental mood (e.g., chronic depression and anxiety) effects on the mother-infant interaction and infant pain and stress reactivity.

Influence of hemodialysis procedure on HCV RNA detection in serum and peripheral blood mononuclear cells.

AIM: To assess whether hemodialysis procedure induces qualitative or quantitative changes in hepatitis C virus (HCV) RNA. METHODS: We obtained blood samples in the 10 HCV RNA-positive patients of our hemodialysis unit before (sample I) and 5 min after a dialysis session (sample II), and before the next dialysis session (sample III). HCV RNA was tested by PCR in serum and peripheral blood mononuclear cells (PBMC). Serum viral load was measured by branched-DNA assay. RESULTS: Serum HCV RNA was positive in samples I, II and III of the 10 patients. PBMC HCV RNA was detected in samples I, II and III of seven patients. Mean viral load was 1.43+/-0.99 Meq genome/mL in sample I, 0.86+/-0.40 Meq genome/mL in sample II and 1.27+/-0.56 Meq genome/mL in sample III. CONCLUSIONS: HCV load was low in most HCV RNA-positive patients. It had a downward trend during dialysis procedure but HCV RNA remained detectable in all serum samples and in most PBMC samples. Therefore, qualitative HCV RNA seems to be better than viral load to assess HCV infection in hemodialysis patients.

Ethological methods to develop nursing knowledge.

Researchers from various fields use ethological methods to systematically observe, describe, and measure animal and human nonverbal behavior. The purpose of this article is to argue that their application in nursing will benefit development of descriptive-level knowledge about complex behavioral phenomena. To advance the argument for applying these methods in nursing, we examine the compatibility of the philosophical assumptions underlying ethology with nursing, assess if ethology can help nursing achieve some of its aims, and determine the benefits of using ethology when observation of a phenomenon is required. Neonatal pain is used to illustrate how ethology can be used to develop descriptive-level nursing knowledge and midrange theory.

Relationship of Ca2+ sparks to STOCs studied with 2D and 3D imaging in feline oesophageal smooth muscle cells.

We recorded Ca2+ sparks and spontaneous transient outward currents (STOCs) simultaneously in smooth muscle cells using whole-cell patch recording and a unique, high-speed widefield digital imaging system to monitor fluo-3 fluorescence in both two and three dimensions (2D and 3D). In 2D imaging, the correlation between the amplitude of a spark and its corresponding STOC was a weak one, and 27 % of the sparks failed to cause STOCs. The STOCless sparks were not significantly different in amplitude from those that caused STOCs. Three-dimensional imaging disclosed that STOCless sparks were located close to the cell surface, and on average their apparent distance from the cell surface was not significantly different from the sparks that cause STOCs. Statistical evaluation of spark clusters disclosed that there were regions of the cell where the probability of spark occurrence was high and others where it was quite low.