Long-Wavelength Quantum Well Infrared Photodetectors

A majority of IR sensors used for imaging arrays operating in the long-wavelength IR region between 8 µm-12 µm are based on mercury cadmium telluride (HgCdTe). This material system is unable to satisfy all the requirements imposed by modem applications. Structural difficulties due to poor uniformity, high defect densities, and weak bond strengths cause difficulties in manufacturing large IR focal plane array cameras. As an alternative, quantum well infrared photodetectors (QWIPs) utilising intersubband absorption between gallium arsenide (GaAs) wells and aluminium gallium arsenide (AIGaAs) barriers were perfected. These QWIPs possess better uniformity in comparison to HgCdTe detectors, and QWIP imaging arrays have recently become commercially available. However, the responsivity of GaAs/AlGaAs QWIPs is still lower than HgCdTe detectors. To further improve the responsivity of QWIP detectors, QWIPs with wells or barriers of GaInAsP instead of AlGaAs have been developed. Results of QWIPs made from the material systems GaAs/GaInP, GaInAs(P)/InP, (Al)GaInAs/InP, and GaInAs/AllnAs have been discussed

Characterization of aroma compounds in Portuguese extra virgin olive oils from Galega vulgar and Cobrançosa cultivars using GC-O and GC-x-GC-ToFMS

Aroma compounds of virgin olive oils extracted from two olive cultivars – Galega Vulgar and Cobrançosa – grown in Beira Baixa region in central Portugalwere investigated. Gas chromatography–olfactometry (GC–O) was carried out to select the important odorants for subsequent comprehensive gas chromatography/time of flightmass spectrometry (GC × GC–ToFMS) analysis. By GC–O fifteen odorants were identified. For the quantification of volatile compounds, headspace solid phasemicroextraction (SPME) techniquewas optimized. Under optimized conditions, 22 volatile compounds were quantified in all samples. Trans-2-hexenal was the most abundant compound. A discriminant analysis (DA) was used to discriminate among olive oil samples obtained from olives of the two cultivars with different harvest time/ripening stages. Concerning the harvesting time and cultivar, nine volatiles showed to have discriminant power among samples, namely heptanal, trans-2-hexenal, 1-octen-1-ol, nonanal, 2,3-butanedione, ethyl-2-methylbutyrate, hexanal, cis-3-hexenylacetate and 3-methylbuthylacetat

RESPIRATORY SOUNDS AS A SOURCE OF INFORMATION IN ASTHMA DIAGNOSIS

Around 300 million people all over the world at all age level suffer from asthma [1]. Patients with this disease have primarily difficult breathing with wheezing in respiratory sounds, cough and feeling of constricted chest. Therefore their physical activity is strongly limited [2]. Nowadays, there are several methods for asthma diagnosis, for example spirometry, measuring of peaks of expiratory velocity or measuring of bronchial reactivity. Although these methods are sufficiently reliable in most cases, they have also some imperfections, which are obvious especially by diagnosing of badly collaborating patients, e.g. small children aged up to three years. These infants can’t provide operations required for diagnosis, so results performed diagnosis are not reliable. For this reason, there is an idea of developing non invasive method of asthma diagnosis and other pulmonary diseases that would not need collaboration of patient [3]. One of the most probably working usable principles is comparison of air flow in airways of healthy and ill person. The difference of the air flow is caused by bronchial obstruction and constriction of airways of patient. There are other sounds and wheezing in the respiratory sounds detectable during breathing as a typical manifestation of the disease [4]. These phenomena can be detected by hearing of sound or by harmonic analysis

Religion, Partisanship, and Attitudes Toward Science Policy

We examine issues involving science which have been contested in recent public debate. These “contested science” issues include human evolution, stem-cell research, and climate change. We find that few respondents evince consistently skeptical attitudes toward science issues, and that religious variables are generally strong predictors of attitudes toward individual issues. Furthermore, and contrary to analyses of elite discourse, partisan identification is not generally predictive of attitudes toward contested scientific issues

Dysregulation of principal cell miRNAs facilitates epigenetic regulation of AQP2 and results in nephrogenic diabetes insipidus

Background MicroRNAs (miRNAs), formed by cleavage of pre-microRNA by the endoribonuclease Dicer, are critical modulators of cell function by post-transcriptionally regulating gene expression. Methods Selective ablation of Dicer in AQP2-expressing cells (DicerAQP2Cre1 mice) was used to investigate the role of miRNAs in the kidney collecting duct of mice. Results The mice had severe polyuria and nephrogenic diabetes insipidus, potentially due to greatly reduced AQP2 and AQP4 levels. Although epithelial sodium channel levels were decreased in cortex and increased in inner medulla, amiloride-sensitive sodium reabsorption was equivalent in DicerAQP2Cre1 mice and controls. Small-RNA sequencing and proteomic analysis revealed 31 and 178 significantly regulated miRNAs and proteins, respectively. Integrated bioinformatic analysis of the miRNAome and proteome suggested alterations in the epigenetic machinery and various transcription factors regulating AQP2 expression in DicerAQP2Cre1 mice. The expression profile and function of three miRNAs (miR-7688-5p, miR-8114, and miR-409-3p) whose predicted targets were involved in epigenetic control (Phf2, Kdm5c, and Kdm4a) or transcriptional regulation (GATA3, GATA2, and ELF3) of AQP2 were validated. Luciferase assays could not demonstrate direct interaction of AQP2 or the three potential transcription factors with miR-7688-5p, miR-8114, and miR-409-3p. However, transfection of respective miRNA mimics reduced AQP2 expression. Chromatin immunoprecipitation assays demonstrated decreased Phf2 and significantly increased Kdm5c interactions at the Aqp2 gene promoter in DicerAQP2Cre1 mice, resulting in decreased RNA Pol II association. Conclusions Novel evidence indicates miRNA-mediated epigenetic regulation of AQP2 expression

Influence of year season on somatic cell count in cow milk collected for the market

Izvršeno je ispitivanje kretanja broja somatskih stanica u kravljemu mlijeku tijekom 12 mjeseci. Praćeno je kretanje po tromjesečnim razdobljima, odnosno godišnjim dobima. Ispitivanje je provedeno na ukupno 461.600 bazenskih uzoraka, dopremanih od većih mljekarskih pogona. Između prosječnoga broja somatskih stanica tijekom 12 mjeseci postoji statistički značajna razlika na oba nivoa (P<0,01; P<0,05). Po tromjesečnim razdobljima postoji također značajna razlika, dok unutar mjeseci svakoga pojedinoga razdoblja tih značajnosti nema, izuzev u prvom razdoblju između 11 i 12 mjeseca, i to samo na 5% nivou. Došlo se do zaključka da stres od zimskoga-hladnoga i ljetnoga-vrućega razdoblja utječe na znatno povećanje broja somatskih stanica u kravljemu mlijeku a time mu znatno umanjuje kakvoću. Ispitivanja su provedena u Središnjem laboratoriju za kontrolu mlijeka, Hrvatskog stočarskog centra.During 12 month period variation of the somatic cell count in milk was studied. Three month period or year season variations was investigated. A total of 461.600 bulk tank samples taken from larger dairies were analyzed. Significant differences at both levels (P<0,01; P<0,05) were determined between the average number of somatic cell count during 12 month period. Significant differences were also determined during three month periods, while within months of every single period significant differences were not determined except only at 5% level in the first period between 11th and 12th month. Conclusion was that stress from winter-cold and summer-hot period had considerable influence on somatic cell count increase in cow milk and therefore it causes considerable milk quality decrease. Investigations were conducted at the Central Laboratory for Milk Control (SLKM) of the Croatian Livestock Centre

DNA hybridization on membrane-modified carbon electrodes

The DNA-modified membrane electrode was prepared by casting a mixture of nitrocellulose (NC) with target DNA (tDNA) in organic solvent on glassy carbon electrode (GCE). Unlabeled polymerase chain reaction (PCR)-amplified human genomic sequence (628 bp) or synthetic oligodeoxynucleotides (ODNs) were used as tDNAs, creating a recognition layer. Biotinylated ODNs were used as hybridization probes to recognize specific nucleotide sequences. The hybridization events were detected via an enzyme-linked electrochemical assay involving binding of streptavidin-coupled alkaline phosphatase (SALP) to the biotin labels of the probe bound to tDNA. After the probe hybridization and SALP binding, the electrode was immersed into an electroinactive enzyme substrate (1-naphthyl phosphate). The alkaline phosphatase converted the inactive substrate into electroactive 1-naphthol that penetrated through the NC membrane to the GCE surface and was subsequently detected using an anodic voltammetric signal. The optimized method offered a good discrimination between complementary and nonspecific DNAs and yielded well-defined responses for both single-copy and repetitive tDNA sequences. In contrast to previously published methods using electrodes with mechanically attached membranes, the previously mentioned electrode is easily amenable to parallel DNA analysis. Copyright © Taylor & Francis, Inc