723 research outputs found
Apparatus for measuring thermal conductivity Patent
Development of apparatus for measuring thermal conductivit
Modulation of social behavior by the agouti pigmentation gene
Agouti is a secreted neuropeptide that acts as an endogenous antagonist of melanocortin receptors. Mice and rats lacking agouti (called non-agouti) have dark fur due to a disinhibition of melanocortin signaling and pigment deposition in the hair follicle. Non-agouti animals have also been reported to exhibit altered behavior, despite no evidence for the expression of agouti outside the skin. Here we confirm that non-agouti mice show altered social behavior and uncover expression of agouti in the preputial gland, a sebaceous organ in the urinary tract that secretes molecules involved in social behavior. Non-agouti mice had enlarged preputial glands and altered levels of putative preputial pheromones and surgical removal of the gland reversed the behavioral phenotype. These findings demonstrate the existence of an autologous, out-of-skin pathway for the modulation of social behavio
Genetic uniqueness and socio-cultural conservation values of the endangered Yakutian Cattle
At the local level the values of the cattle were more related to everyday livelihood strategies of single households and families, whereas the representatives of the republic, in line with the newspapers, highlighted the importance of the cattle for Sakha's food production and for national identity. Thus, individuals at different levels were in favour of conserving the cattle, but for different reasons. The local residents and experts were more concerned about developing economically sustainable cattle production, whereas the experts in Yakutsk were concerned about the conservation of genetic resources. The genetic studies have indicated that Yakutian Cattle show genetic distinctiveness and have genetic value for the maintenance of cattle diversity
How does teachers’ professional agency in the classroom change in the professional transition from early career teachers to more experienced ones?
Professional agency is key for teachers’ professional development, for constructing their professional identity, and for promoting student learning. This longitudinal study explored the development of teachers’ (N = 201) sense of professional agency in the classroom in the professional transition from early career teachers to more experienced ones. We used latent profile analysis to examine the individual variation and change in teachers’ sense of professional agency in the classroom in a five-year follow-up. The results showed three distinctive profiles: a high sense of professional agency (64%), a moderate sense of professional agency (32%), and a low sense of professional agency (4%) in the classroom. The changes detected in the three teachers’ sense of professional agency profiles varied. The profiles were associated with teacher groups (i.e., primary teachers, subject teachers, and special education teachers), but not with stress, attrition intention or school size. The results imply that teachers’ sense of professional agency in the classroom does not always increase in tandem with experience, and thus, different kinds of support are needed for cultivating teachers’ sense of professional agency over time.Peer reviewe
Low-level gas multicounter for C-14 dating of small samples: Electronic, numerical and shielding optimisation
Up to 14 methane samples can be dated simultaneously in our compact gas multicounter. Sample detectors are 10 ml (NTP) in volume each. They are made of copper and linked to form two 7 detector rigid assemblies which are filled in situ. Monitoring of the counting conditions is enabled through multichannel analysis of the cosmic pulse height spectrum, which shows the changes in gas amplification due to impurities or leakage. HV is set (and adjusted) automatically using the cosmic peak. All individual events are stored on disc, including pulse height (PH), risetime (RT) (both 256 Ch), time of arrival (TA), detector identification, anticoincidence status and elapsed and live time. Software programs analyse and validate data. Numerical discrimination and manipulations of counting parameters can be performed without destroying the original data set. Statistical quality control is based on chi-square and Poisson distribution of count rates around their mean in user defined energy regions as weil as time of arrival of pulses mode. TA analysis offers the user an early means for recognizing some types of system malfunction that otherwise might remain undetected for Jong periods of time. RT analysis is used to discriminate sample beta pulses from environmental radiation pulses, resulting in a low background with compact and relat ively inexpensive shielding. The automatic high voltage setting, PH, RT and TA electronics as weil as the liquid scintillation anticoincidence systems are applicable to all existing gas counting systems.
Delivery of the gas multicounter to the Australian National University is to take place at the end of the year 1984
Low-level liquid scintillation spectrometer for Ăź-counting
A new liquid scintillation (LS) spectrometer has been developed. lt improves the signal to noise ratio of C-14 assays by an order of magnitude compared to conventional LS systems. As a result, precision for a modern sample is 0.2 % and the dating limit is 64 Ky BP for a 15 ml sample of benzene. Sophisticated MCA facilities allow the use of Multiparameter Multichannel Analysis for data validation and age evaluation. Despite the high sophistication, the spectrometer, (named QUANTULUS) is seif contained, microprocessor controlled and user friendly. lt can be used with full advantage in a normal laboratory environment
A time-resolved fluorescence immunoassay for the measurement of testosterone in saliva: Monitoring of testosterone replacement therapy with testosterone buciclate
Monitoring of testosterone replacement therapy requires a reliable method for testosterone measurement. Determination of salivary testosterone, which reflects the hormone's biologically active plasma fraction, is a superior technique for this purpose. The aim of the present study was to establish a new sensitive time-resolved fluorescence immunoassay for the accurate measurement of testosterone levels in saliva and to validate it by monitoring testosterone replacement therapy in eight hypogonadal men. A clinical phase I- study with the new ester testosterone buciclate was performed to search for new testosterone preparations to produce constant serum levels in the therapy of male hypogonadism. After two control examinations eight male patients with primary hypogonadism were randomly assigned to two treatment groups (n = 2x4) and given single doses of either 200 mg (group I) or 600 mg (group II) testosterone buciclate intramuscularly. Saliva and blood samples were obtained 1, 2, 3, 5 and 7 days post injection and then weekly for three months. The time-resolved fluorescence immunoassay for salivary testosterone shows a detection limit of 16 pmol/l, an intra-assay CV of 8.9% (at a testosterone concentration of 302 pmol/l), an inter-assay CV of 8.7% (at a testosterone concentration of 305 pmol/l) and a good correlation with an established radioimmunsassay of r = 0.89. The sample volume required by this method is only 180 mu l for extraction and duplicate determination. The assay procedure requires no more than three hours. In group I (200 mg) testosterone did not increase to normal levels either in saliva or in serum. However, in group II, androgen levels increased significantly and were maintained in the normal range for up to 12 weeks with maximal salivary testosterone levels of 303 +/- 18 pmol/l (mean+/-SE) and maximal testosterone levels of 13.1 +/- 0.9 nmol/l (mean+/-SE) in serum in study week 6 and 7. The time-resolved fluorescence immunoassay for salivary testosterone provides a useful tool for monitoring androgen status in men and women and is well suited for the follow-up of testosterone replacement therapy on an outpatient basis. The long-acting ester testosterone buciclate is a promising agent for substitution therapy of male hypogonadism and in combination with testosterone monitoring in saliva offers an interesting new perspective for male contraception
Molecular Differentiation of Mycobacterium tuberculosis Strains without IS6110 Insertions
By using standard restriction fragment length polymorphism, 6 zero-copy IS6110
Mycobacterium tuberculosis isolates were identified from 1,180 Maryland isolates as part of the National Tuberculosis Genotyping Surveillance Network Project. By using various genotyping methods, we demonstrated that this zero band cluster can be differentiated into six genotypes
Manganese superoxide dismutase as a diagnostic marker for malignant pleural mesothelioma
Although several immunohistochemical markers are available, differential diagnosis between mesothelioma and metastatic adenocarcinoma of the pleura is difficult. We have found that the immunoreactivity of manganese superoxide dismutase (MnSOD), an important antioxidant enzyme, is high in mesothelioma compared to healthy pleural mesothelium. The aim of the present study was to investigate whether MnSOD can be used in the differential diagnosis of malignant mesothelioma and metastatic adenocarcinoma of the pleura. MnSOD expression was assessed by using immunohistochemistry in biopsies of malignant mesothelioma (n = 35) and metastatic adenocarcinoma of the pleura (n = 21). MnSOD immunoreactivity was assessed semiquantitatively with and without microwave pretreatment. Fifteen of the 35 malignant mesotheliomas showed moderate or strong MnSOD expression without and 23 with microwave pretreatment, the corresponding figures for metastatic adenocarcinoma of the pleura being 1 and 2 out of 21 (P = 0.002 and P< 0.001, respectively by Fisher's exact test). Only mesothelioma biopsies showed strong MnSOD reactivity, and it was never negative in mesothelioma, whereas one-third of the adenocarcinomas showed no MnSOD reactivity. In conclusion, MnSOD immunoreactivity can, combined with other markers, aid the differential diagnosis between malignant mesothelioma and metastatic adenocarcinoma of the pleura. © 2000Cancer Research Campaig
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