All-POF coupling ratio-imbalanced Sagnac interferometer as a refractive index sensor.

A polymer optical Sagnac interferometer is proposed as a compact and low-cost refractive index sensor for the first time to our best knowledge. The Sagnac interferometer is fabricated by only one piece of fiber to facilitate its fabrication and to avoid losses due to misalignment or fusion. The coupler was developed based on chemical and twisting techniques of ∼5cm of fiber. We modified the coupling ratio by varying the refractive index of media surrounding the coupler and consequently modified the transmission. For several values of mass percent concentration of sugar solutions surrounding the coupler, we found that transmittance decreases as the mass concentration increases. However, the decay is faster for the low concentration, while the decay is slower for higher concentrations. Two sets of experiments were carried out, at high (≥ 1 gm/100 ml) and low (<1gm/100ml) mass concentration of sugar solutions. The calibration of the sensor was done at 733 nm, where the response of the interferometer displays larger transmission variations for different solutions. The refractive index estimation was possible by correlation of the transmittance function (calculated by fitting the experimental data) with a linear refractive index model. The estimated resolution of the system is 0.057 weight percent of sugar solution, determined by the noise of the system.

Feature Extraction from Distributions of Phase Synchronization Values of EEG Recordings

ABSTRACT Epilepsy is the most common neurological pathology. Despite treatments available to patients, only 58% to 73% will be free of seizures. This uncertainty in treatment outcomes can lead to other psychiatric affectations in cases where treatment success may be in doubt. Seizure prediction models (SPMs) emerged as a measure to help determine when patients may be susceptible to an imminent crisis. These models are based on the continuous monitoring of patient's EEG signals and subsequent continuous analysis to identify features that differentiate ictal from interictal states. This is an ongoing field of research whose aim is to establish a robust set of features to feed the SPM and obtain a high degree of certainty regarding when the next seizure will occur. In this work we propose the analysis of phase differences of EEG as a method to extract features capable of discriminating ictal and preictal states in patients; specifically, the numeric distance between Q1 and Q3 of the distribution of phase differences. We compared this values to other phase synchronization methods and tested our hypothesis getting a p < 0.0009 with our proposed method.

Growth performance and carcass traits of steers finished on three different systems including legume-grass pasture and grain diets.

Inclusion of legume in grass pastures optimizes protein values of the forage and promotes improved digestibility. Therefore, we hypothesized that finishing steers on a novel combination of legumes and grass pasture would produce carcasses with acceptable traits when compared to carcasses from steers finished in feedlot systems. In this study, we evaluated the effects of finishing steers on three systems including: grazing legume-grass pasture containing oats, ryegrass, white and red clover (PAST), grazing PAST plus supplementation with whole corn grain (14 g/kg BW (SUPP)), and on a feedlot-confined system with concentrate only (28 g/kg BW, consisting of 850 g/kg of whole corn grain and 150 g/kg of protein-mineral-vitamin supplement (GRAIN)) on growth performance of steers, carcass traits and digestive disorders. Eighteen steers were randomly assigned to one of three dietary treatments and finished for 91 days. Data regarding pasture and growth performance were collected during three different periods (0 to 28, 29 to 56 and 57 to 91 days). Subsequently, steers were harvested to evaluate carcass traits, presence of rumenitis, abomasitis and liver abscesses. The legume-grass pasture provided more than 19% dry matter of protein. In addition, pasture of paddocks where steers were assigned to SUPP and PAST treatments showed similar nutritional quality. When compared to PAST, finishing on SUPP increased total weight gain per hectare, stocking rate, daily and total weight gains. The increase of weight gain was high to GRAIN than SUPP and PAST. Steers finished on GRAIN had high hot carcass weight, fat thickness and marbling score when compared to PAST. However, these attributes did not differ between GRAIN and SUPP. Abomasum lesions were more prevalent in steers finished on GRAIN when compared to PAST. Results of this research showed that it is possible to produce carcasses with desirable market weight and fat thickness by finishing steers on legume-grass pasture containing oats, ryegrass, white and red clover. Moreover, supplementing steers with corn when grazing on legume-grass pasture produced similar carcass traits when compared to beef fed corn only.

Effect of recombinant prophenin 2 on the integrity and viability of Trichomonas vaginalis.

Trichomonas vaginalis is the causal agent of trichomoniasis, which is associated with preterm child delivery, low birth weight, and an increased risk of infection by human papilloma virus and human immunodeficiency virus following exposure. Several reports have established increasing numbers of trichomoniasis cases resistant to metronidazole, the agent used for treatment, and it is therefore important to identify new therapeutic alternatives. Previously, our group reported the effect of tritrpticin, a synthetic peptide derived from porcine prophenin, on T. vaginalis; however, the hemolytic activity of this small peptide complicates its possible use as a therapeutic agent. In this study, we report that the propeptide and the processed peptide of prophenin 2 (cleaved with hydroxylamine) affected the integrity and growth of T. vaginalis and that pro-prophenin 2 displays some resistance to proteolysis by T. vaginalis proteinases at 1 h. Its effect on T. vaginalis as well as its low hemolytic activity and short-time stability to parasite proteinases makes prophenin 2 an interesting candidate for synergistic or alternative treatment against T. vaginalis.

Biological soil crusts across disturbance­recovery scenarios: effect of grazing regime on community dynamics.

Grazing represents one of the most common disturbances in drylands worldwide, affecting both ecosystem structure and functioning. Despite the efforts to understand the nature and magnitude of grazing effects on ecosystem components and processes, contrasting results continue to arise. This is particularly remarkable for the biological soil crust (BSC) communities (i.e., cyanobacteria, lichens, and bryophytes), which play an important role in soil dynamics. Here we evaluated simultaneously the effect of grazing impact on BSC communities (resistance) and recovery after livestock exclusion (resilience) in a semiarid grassland of Central Mexico. In particular, we examined BSC species distribution, species richness, taxonomical group cover (i.e., cyanobacteria, lichen, bryophyte), and composition along a disturbance gradient with different grazing regimes (low, medium, high impact) and along a recovery gradient with differently aged livestock exclosures (short-, medium-, long-term exclusion). Differences in grazing impact and time of recovery from grazing both resulted in slight changes in species richness; however, there were pronounced shifts in species composition and group cover. We found we could distinguish four highly diverse and dynamic BSC species groups: (1) species with high resistance and resilience to grazing, (2) species with high resistance but low resilience, (3) species with low resistance but high resilience, and (4) species with low resistance and resilience. While disturbance resulted in a novel diversity configuration, which may profoundly affect ecosystem functioning, we observed that 10 years of disturbance removal did not lead to the ecosystem structure found after 27 years of recovery. These findings are an important contribution to our understanding of BCS dynamics from a species and community perspective placed in a land use change context.

Common genetic variants in the chromogranin A promoter alter autonomic activity and blood pressure.

Chromogranin A (CHGA) is stored and released from the same secretory vesicles that contain catecholamines in chromaffin cells and noradrenergic neurons. We had previously identified common genetic variants at the CHGA locus in several human populations. Here we focus on whether inter-individual variants in the promoter region are of physiological significance. A common haplotype, CGATA (Hap-B), blunted the blood pressure response to cold stress and the effect exhibited molecular heterosis with the greatest blood pressure change found in Hap-A/Hap-B heterozygotes. Homozygosity for three minor alleles with peak effects within the haplotype predicted lower stress-induced blood pressure changes. The G-462A variant predicted resting blood pressure in the population with higher pressures occurring in heterozygotes (heterosis). Using cells transfected with CHGA promoter-luciferase reporter constructs, the Hap-B haplotype had decreased luciferase expression compared to the TTGTC (Hap-A) haplotype under both basal conditions and after activation by pre-ganglionic stimuli. The G-462A variant altered a COUP-TF transcriptional control motif. The two alleles in transfected promoters differed in basal activity and in the responses to COUP-II-TF transactivation and to retinoic acid. In vitro findings of molecular heterosis were also noted with the transfected CHGA promoter wherein the diploid combination of the two G-462A alleles gave rise to higher luciferase expression than either allele in isolation. Our results suggest that common genetic variants in the CHGA promoter may regulate heritable changes in blood pressure.

In the general hospital: A doctors’perception survey

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Psychosocial factors play an important role in the clinical practice in the general hospital. The main objective of this study is to evaluate the relevance assigned by non psychiatry physicians who work in a teaching general hospital, to psychosocial factors in the context of their day-to-day clinical practice, and the coping strategies they adopt to deal with them. A second objective is to assess the evaluation of the Consultation- Liaison (C-L) service in a teaching hospital. Method: A previous questionnaire about perception of psychosocial factors in the general hospital (1) was adapted. Our questionnaire consists of 3 sections. A first section gathers socio-demographic information of surveyed physicians; a second section evaluates the relevance assigned by non psychiatry physicians to psychosocial factors, and their coping strategies, and finally, a third new section designed to provide an evaluation of our C-L unit service provision by non psychiatry physicians. Results: Of a total of 219 non specialty physicians responding to the survey, 35.5% stated they had adequate knowledge of psychiatric disorders, 87.3% considered that psychosocial factors influence the origin and prognosis of physical illnesses and 99.5% considered that social and emotional aspects play an important role in their clinical practice. 79.6% considered psychiatrists to be essential for the care of hospitalized patients. Statistical significance was set at 5%.Conclusion(s): This paper highlights the relevance attributed to psychosocial factors in clinical practice and the importance assigned to the C-L services by non specialty physicians of a teaching general hospital (AU)

Prevalence and correlates of migraine among women attending a prenatal care clinic in Lima, Peru.

Migraine headaches are among the leading causes of disability in the world. The burden of migraines is highest in women of reproductive age. This cross-sectional study characterized the prevalence, symptoms and correlates of migrainous headaches in 154 pregnant women attending a prenatal care clinic in Lima, Peru. Lifetime prevalence of migraine defined by modified IHS criteria was 9.1% (95% CI 4.6-13.6). When probable migraines were included, the lifetime prevalence of migraine in this population was 29.2% (95% CI 22.0-36.4). Migraine headaches were associated with a maternal history of headache, childhood carsickness, a diagnosis of allergies, and a high frequency of fatigue. Although headache-related disability was low in terms of missed work and recreation, high rates of headache pain and medicinal use reflect the true impact on this population.

Calorimetric and FTIR study of the acid properties of sulfated titanias.

Titanium oxides of different surface areas were sulfated then calcined to convert the solid to a strong acid. The amount of sulfur retained by the solid and the thermal stability of the resulting sulfate are controlled by the dispersion of the initial oxide. The acid properties were determined by gravimetry at 383 K, calorimetry using ammonia adsorption at 353 K, and by quantitative analysis of the infrared spectra of pyridine retained after evacuation at 423 K. A good agreement was observed between the different determinations. At low coverage of ammonia, sulfated titanias show a much lower heat of adsorption, and the IR study of NH3 adsorption shows that the first doses of NH3 dissociate at the surface with the formation of OH species. The lower heat of adsorption is then attributed to the contribution of NH3 dissociation to the differential heat of adsorption. IR spectroscopy indicates that NH3 reacts with sulfates and may lead to the transformation of disulfate species into monosulfate species on sulfated titania dioxide. A band at ca. 3574 cm-1 has been assigned to nu(OH) of monosulfate species. This particular behavior makes it difficult to appreciate the initial acidity of these sulfated oxides.

Quality of care of patients hospitalized with congestive heart failure.

BACKGROUND: Congestive heart failure (CHF) is an increasingly prevalent poor-prognosis condition for which effective interventions are available. It is -therefore important to determine the extent to which patients with CHF receive appropriate care in Australian hospitals and identify ways for improving suboptimal care, if it exists. AIM: To evaluate the quality of in-hospital acute care of patients with CHF using explicit quality indicators based on published guidelines. METHODS: A retrospective case note review was -performed, involving 216 patients admitted to three teaching hospitals in Brisbane, Queensland, Australia, between October 2000 and April 2001. Outcome measures were process-of-care quality -indicators calculated as proportions of all, or strongly -eligible (ideal), patients who received -specific interventions. RESULTS: Assessment of underlying causes and acute precipitating factors was undertaken in 86% and 76% of patients, respectively, and objective evaluation of left ventricular function was performed in 62% of patients. Prophylaxis for deep venous thrombosis (DVT) was used in only 29% of ideal patients. Proportions of ideal patients receiving pharmacological treatments at discharge were: (i) angiotensin--converting enzyme inhibitors (ACEi) (82%), (ii) target doses of ACEi (61%), (iii) alternative vasodilators in patients ineligible for ACEi (20%), (iv) beta-blockers (40%) and (v) warfarin (46%). CONCLUSIONS: Opportunities exist for improving quality of in-hospital care of patients with CHF, -particularly for optimal prescribing of: (i) DVT prophylaxis, (ii) ACEi, (iii) second-line vasodilators, (iv) beta-blockers and (v) warfarin. More research is needed to identify methods for improving quality of in-hospital care.

Quality of care of patients hospitalized with acute coronary syndromes.

BACKGROUND: Measurement and improvement of quality of care is a priority issue in health care. Patients hospitalized with acute coronary syndromes (ACS) constitute a high-risk population whose care, if shown to be suboptimal on the basis of available research evidence, may benefit from quality improvement interventions. AIM: To evaluate the quality of in-hospital care for patients with ACS, using explicit quality indicators. METHODS: Retrospective case note review was undertaken of 397 patients admitted to three teaching hospitals in Brisbane, Queensland, Australia, between 1 October 2000 and 17 April 2001. The main outcome measures were 12 process-of-care quality indicators, calculated as either: (i) the proportion of all patients who received specific interventions or (ii) the proportion of ideal patients who received specific interventions (i.e. patients with clear indications and lacking contraindications). RESULTS: Quality indicators with values above 80% included: (i) patient selection for thrombolysis (100%) and discharge prescription of beta-blockers (84%), (ii) antiplatelet agents (94%) and (iii) lipid-lowering agents (82%). Indicators with values between 50% and 80% included: (i) timely performance of electrocardiogram (ECG) on admission (61%), (ii) early coronary angiography (75%), (iii) measurement of serum lipids (71%) and (iv) discharge prescription of angiotensin-converting-enzyme (ACE) inhibitors (73%). Indicators with values <50% included: (i) timely administration of thrombolysis (35%), (ii) non-invasive risk assessment (23%) and (ii) formal in-hospital, and post-hospital cardiac rehabilitation (47% and 7%, respectively). CONCLUSION: There were delays in performing ECG and administering thrombolysis to patients who presented to emergency departments with ACS. Improvement is warranted in use of non-invasive procedures for identifying high-risk patients who may benefit from coronary revascularization as well as use of serum lipid measurements, ACE inhibitors and cardiac rehabilitation.

Population growth of Euchlanis dilatata (Rotifera): combined effects of methyl parathion and food (Chlorella vulgaris).

In the present work, the combined impact of four concentrations (0, 0.0625, 0.125, and 0.25 mg/L) of methyl parathion and three densities (0.5 x 10(6), 1.0 x 10(6), and 2.0 x 10(6) cells/mL) of the green alga Chlorella vulgaris on the population growth of Euchlanis dilatata was studied. In general, regardless of the food level, an increase in the concentration of methyl parathion resulted in a significant reduction of the maximal population density and rate of population increase. The population growth rate in the controls ranged from 0.248 to 0.298; rates were lower in the presence of the pesticide. At any toxicant concentration, rotifers fed higher algal density showed significantly higher population growth compared with those at lower food levels. An interaction between toxicant and food level was evident on the population growth of E. dilatata. Results have been discussed in light of the protective role of algal density on the toxic effects of insecticides on rotifers and the differences in susceptibility to toxicants between planktonic and littoral rotifers.

Effect of methyl parathion on the population growth of the rotifer Brachionus patulus (O. F. Müller) under different algal food (Chlorella vulgaris) densities.

The population growth of the rotifer Brachionus patulus was studied under a combination of different concentrations of Chlorella vulgaris and methyl parathion. To obtain sublethal concentrations of the pesticide a 24-h LC(50) bioassay was performed under two food densities (1.5 and 3.0x10(6) cells ml(-1)) using neonate rotifers. For the population growth experiments, seven toxicant concentrations were used ranging from 0.16 to 10.0 mg L(-1) and four food densities (0.75, 1.5, 3.0, and 6.0x10(6) cells ml(-1)), each with four replicates and thus in all, 128 test jars. A medium with Chlorella alone and without toxicant acted as control. The initial density of the rotifers in each replicate were 5 individual ml(-1). Experiments were conducted for 20 days. The LC(50) values of B. patulus were 8.8 and 10.7 mg L(-1) at low and high algal food density, respectively. Data on the population growth studies revealed a significant effect of both food density and toxicant concentration on the maximum abundance, day at which maximum abundance was reached, and rate of population increase per day. At any toxicant concentration, an increase in food density reduced the toxicity of methyl parathion to rotifers. In controls the maximum rotifer density under the highest food level (6x10(6) cells ml(-1)) was 795+/-46 individuals ml(-1). The rate of population increase per day (r) in controls varied from 0.22+/-0.01 to 0.34+/-0.01 depending on food density. Algal food density had a significant influence in reducing the toxicity of methyl parathion to B. patulus under both acute and chronic toxicity test conditions.

Blood acid-base and serum electrolyte values in red deer (Cervus elaphus).

Acid-base, serum electrolyte, plasma protein, and packed cell volume (PCV) values were determined in venous blood samples from 30 red deer (Cervus elaphus) of both sexes showing no clinical signs of disease. The animals were 5 months of age and kept on pasture in the Valley of Mexico, at an altitude of 2450 m. Blood samples were collected without sedation. Mean blood values were: pH 7.411 +/- 0.041, pCO2 37.7 +/- 4.4 mmHg, base excess 0.7 +/- 3.2 mmol/L, actual bicarbonate 24.3 +/- 3.1 mmol/L, total CO2 25.3 +/- 3.2 mmol/L and anion gap 23.5 +/- 5.5 mmol/L. Mean serum electrolyte levels were: Na+ 142.3 +/- 2.5 mmol/L, Cl- 100.5 +/- 2.3 mmol/L, and K+ 7.03 +/- 1.03 mmol/L. Plasma protein and PCV values were 60.0 +/- 6.6 g/L and 0.47 +/- 0.05 L/L, respectively. Blood values determined in this study can be considered reference data for health control and disease diagnosis.

Design of a diluted aperture by use of the practical cutoff frequency.

We analyze the imaging performance of a number of diluted-aperture configurations, using the modulation transfer function. We select a single figure of merit, the practical cutoff frequency, rather than the traditional cutoff frequency, as the more useful frequency for the detection of details. Using this new parameter, we compare the performance of a number of published aperture configurations. On the basis of this analysis a new configuration is proposed for the Polar Stratospheric Telescope primary.

Syphilis. A tale of twisted treponemes.

Despite the widespread availability of effective treatment, the incidence of primary and secondary syphilis in the United States is on the rise. In addition, syphilis is occurring in a substantial number of patients infected with the human immunodeficiency virus (HIV), thus adding to the complexities of diagnosis and treatment. Primary syphilis represents a disseminated infection, often accompanied by abnormalities of the cerebrospinal fluid, that may pass unrecognized and progress to the myriad manifestations of secondary syphilis. The diagnosis of syphilis in patients with mucosal or skin lesions may be made by darkfield examination; once lesions have resolved, serologic tests are required. Patients with latent syphilis may have asymptomatic neurosyphilis and risk progression to tertiary disease. The diagnosis of asymptomatic neurosyphilis is necessary to determine the optimal treatment of patients with latent disease. The diagnosis of active neurosyphilis generally requires an inflammatory cerebrospinal fluid profile and a reactive cerebrospinal fluid VDRL test. Syphilis is common in HIV-infected patients, who may have an altered antibody response to infection and an apparent increased incidence of neurologic complications. The preferred treatment at all stages is penicillin, which is also the only recommended therapy for neurosyphilis. The optimal treatment of syphilis in HIV-infected patients is unknown.

[Role of ambulatory blood pressure measurement in the evaluation of the cardiovascular load in high altitude workers]. / Place de la mesure de la pression artérielle en ambulatoire dans l'évaluation de la charge cardiovasculaire de salariés travaillant en haute altitude.

UNLABELLED: This study evaluates ambulatory blood pressure ABP measurement as a technique for measuring the cardiovascular load in maintenance mechanics working on mechanical lifts at altitudes of over 2,500 meters (stress due to altitude and intensive static and dynamic work). METHOD: 25 normotensive workers were studied during real working conditions. Each subject underwent a maximal stress test, and echocardiography. An ABP recording (Spacelab 90207) with BP measurement every 15 minutes and continuous heart rate (HR) monitoring (Essilor IFC85), during 24 hours were performed on the same day. ANALYSIS: study of BP levels and their factors of variation, comparison of this data with continuous HR measurements, and with results of the stress test and echocardiography. RESULTS: even in difficult conditions (while balancing on cables and cable towers), ABP measurements is possible (less than 10% missing values). Systolic (SBP) and diastolic (DBP) blood pressure and HR values adjusted for age are significantly higher during work activity (9:00-12:00, 14:00-15:00) in these subjects than in reference normotensive subjects. ABP did not differ significantly between different types of work while the equivalent mechanical load (work load that gives a stress test HR equal to the mean HR during work) reveals a different between work activities. At night SBP remains higher and HR values lower than in control subjects. In comparison with reference criteria, 3 subjects were considered as having an abnormally high ABP during the daytime. ABP results were not linked with number of years in the profession nor with the altitude at which the subject worked or lived. Although 40% of subjects have a left ventricular mass index greater than 135 g:m2, there is no link between ultrasound and ABP parameters. CONCLUSION: while ABP measurement seems possible in this type of professional activity, BP values do not appear to be correlated to work level measured. The absence of correlation with left ventricular mass, suggests that the process of cardiovascular adaptation is different from that in even moderately hypertensive subjects.