Should atrial septal defects in adults be closed?

BACKGROUND: By assessing current surgical outcome and symptomatic relief, this study attempts to answer whether atrial septal defects in adults should be closed. METHODS: Thirty-nine adult patients aged 35.2 +/- 13.6 years underwent operation for an atrial septal defect between June 1988 and June 1994. Indications for closure were symptoms (33 patients) or a significant left-to-right atrial shunt (6 patients). Data were obtained from hospital records, and the latest status of the patients was determined by a written questionnaire. RESULTS: There were no deaths. Pulmonary embolism in 1 patient was the only complication observed. The QRS duration on the surface electrocardiogram decreased immediately (p < 0.001), and the cardiothoracic ratio on chest radiographs was significantly lower 3 to 6 months after operation (p < 0.001), both findings reflecting improved hemodynamics. No residual shunts were seen on follow-up (mean follow-up, 3.3 +/- 2.2 years). Twenty-seven (81.8%) of the 33 symptomatic patients improved clinically in terms of exercise performance, atrial arrhythmias, or both. Three (50%) of the 6 previously asymptomatic patients reported improved functional capacity post-operatively. CONCLUSIONS: Today, operation for atrial septal defects in adults can be performed with no mortality and low morbidity and results in symptomatic improvement in the majority of patients. Clinical improvement was seen even in patients who considered themselves asymptomatic preoperatively. We advocate closure of atrial septal defects in adult patients with symptoms or significant atrial shunts.     

Polarization behavior of birefringent multitransverse mode vertical-cavity surface-emitting lasers

An analysis has been undertaken of the effect of birefringence on the selection of polarization states of a weakly index guided vertical-cavity surface-emitting laser (VCSEL) supporting both a fundamental and a first-order transverse mode. It is shown that for small index steps polarization switching due to spatial-hole burning effects can occur. For larger index steps it is found that higher order modes can emerge which are orthogonally polarized to the dominant polarization of the fundamental mode.     

Optical frequency-domain ranging using a frequency-shifted feedback distributed-feedback laser

A distributed-feedback (DFB) laser is used in a frequency-shifted external cavity configuration to generate a frequency comb. The frequency comb generates a beat frequency in a Michelson interferometer, which is proportional to the path difference of a target and reference arm. The calculated and actual readings for the beat frequency are in good agreement. A proof of principle demonstration of using a DFB laser for optical frequency-domain ranging is shown for the first time.     

Fatty amidoamine derivatives: N,N-dimethyl-N-(3-alkylamidopropyl)amines and their salts

A group of cationic surfactants based on N-alkylamidopropyl-N,N-dimethylamines, R-CONHCH₂CH₂CH₂N(CH₃)₂, was studied. Caprylamidopropyl, capramidopropyl, lauramidopropyl, stearamidopropyl and oleamidopropyl dimethylamines were prepared, purified and characterized. NMR, IR, and pK_b data are reported. The acetate and methylchloride quaternary salts of these amines were also prepared and evaluated as bactericides gelling agents, and foaming surfactants. Surface tensions, interfacial tensions, critical micelle concentrations and Ross-Miles foam heights were determined. N-(3-dimethylaminopropyl)stearamide formed well structured gels in white mineral oil and deodorized kerosene. Further, these amidoamines and their salts showed excellent antistatic properties and were substantive to hair and skin. Presented at the AOCS Meeting, Chicago, October 1967.     

Do girls talk earlier?: Mean length of utterance in toddlers.

Notes that although older studies present consistent evidence that girls are advanced in language acquisition, newer findings are equivocal. This discrepancy might be due to a change in methodological approach. Older studies provide data on mean length of utterance (MLU) in sizable samples of toddlers. Since this methodological approach has proved to be sound in view of recent advances in developmental psycholinguistics, it was surprising to find that none of the newer studies had adopted it. To see if the discrepancy in the literature was due to a change in method or in children, the method of the older studies was applied to a contemporary sample. 66 younger toddlers (mean age 23.8 mo) and 64 older toddlers (mean age 28.57 mo) with sexes matched for age, class, and race were studied. Younger toddler girls were significantly advanced in MLU (words or morphemes) and also in upper bound (UB), length of longest utterance (words or morphemes). Older toddler girls were significantly advanced in UB, with the increment in MLU approaching significance. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sibling deidentification.

Uses "sibling deidentification" to refer to a commonplace phenomenon (i.e., judgments of being different from one's sibling. The present study examined its possible determinants and attempted to clarify what Ss mean when they judge siblings to be different. Results on alike-different judgments elicited from 383 undergraduates, 203 from 3-child and 180 from 2-child families, show significantly higher levels of deidentification for first pairs, firstborn S judging 2nd born sibling (S1Sb2) or 2nd-born S judging first sibling (S2Sb1), than for jump pairs (S1Sb3 or S3Sb1), with intermediate levels for 2nd pairs (S2Sb3 or S3Sb2). There were no significant within-pair effects of birth order, sex of S, and spacing. For 3-child first pairs, same-sex siblings deidentified significantly more than opposite-sex siblings did. Results on semantic differentials indicate that when Ss judged their sibling different they meant that they polarized on signficantly more personality dimensions than did those judging alike. Findings in conjunction with identification theory suggest that deidentification may be a mechanism for resolving sibling rivalry, a Cain Complex. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interferometric analysis of nanostructured surface profiles: correcting material-dependent phase shifts

We present a technique to correct interferometry for the material-dependent phase shift that accompanies reflection. Such corrections are needed for nanometer accuracy of surfaces that are not of homogeneous composition. We adapt the general theory of reflection from surfaces in which there are irregular and unresolved areas of several materials to treat the specific case in which only two materials are present, as is the case for many practical applications. We show, for the approximation of a large numerical aperture that collects all reflected light, how measurements of three quantities, together with known values of the optical constants, allow determination of the material-dependent phase shift at each position on the surface. We demonstrate with numerical simulation, appropriate to measuring a surface of alumina in which optically unresolved titanium carbide granules are embedded, that our approach also succeeds, with nanometer accuracy, when the numerical aperture is small. The method is discussed for use with a miniature interferometric phase sensor, but it has application to any interferometer.     

Organochlorine pesticide, polychlorinated biphenyl and heavy metal concentrations in wolves (Canis lupus L. 1758) from north-west Russia

The wolf Canis lupus is a major terrestrial predator in eastern Europe and, as a top carnivore, may be exposed to high concentrations of contaminants that are readily transferred through the food chain. Despite this, there are few published data on pollutant and pesticide levels in wolves. This study utilised tissues from animals legally killed by hunters for other reasons (animals were not killed for the purposes of this study) to carry out the only detailed investigation of contaminants in wolves in Europe and the first in animals from Eastern Europe. The livers of 58 wolves from the Tver and Smoliensk regions of northwest Russia (54°N 31°E to 57°N 35°E) were analysed for seven organochlorine pesticides, 24 PCB congeners, Aroclor 1254-matched summed PCBs (ΣPCBs), total mercury, cadmium and lead. Cadmium, most of the organochlorine pesticides and many PCB congeners were not detectable in any of the wolves. Hexachlorobenzene, alpha-HCH, pp′DDE, PCB congeners 118, 138, 149 and 156 and lead were detected in up to 6% of livers. Dieldrin, PCB congeners 153, 170 and 180, ΣPCBs and mercury were detected more frequently. Contaminant levels were generally low; maximum wet weight concentrations of any of the organochlorine pesticides, ΣPCBs and mercury were less than 0.1, 1 and 0.25 μg g⁻¹, respectively. PCB congeners 153, 170 and 180 accounted for 41% of the ΣPCBs. Dieldrin, ΣPCBs and mercury concentrations did not vary significantly between males and females nor between adult and juvenile (<12 months old) wolves apart from the ΣPCB concentration, which was on average five times higher in adults than juveniles. Liver residues were generally below the level normally associated with adverse effects except for lead levels which exceeded the critical 5 μg g⁻¹ dry wt. concentration in three of the 58 animals examined.