779 research outputs found
Electrochemically copper-doped bismuth tellurium selenide thin films
We report the first results of a study on electrochemically doped copper bismuth tellurium selenide thin films electrodeposited from aqueous nitric acid electrolytes containing up to 2âŻmM of Cu(NO3)2. The effect of Cu(NO3)2 concentration on the composition, structure and thermoelectric properties of the bismuth tellurium selenide films is investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Seebeck and Hall effect measurements. A Cu(NO3)2 concentration of 1.5âŻmM is found to offer a Seebeck coefficient of up to â390âŻÎŒVâŻKâ1 at room temperature, which is the highest reported to date for an electrodeposited bismuth tellurium compound
Sleep abnormalities in the synaptopathiesâSYNGAP1-related intellectual disability and PhelanâMcDermid syndrome
Neurodevelopmental disorders are frequently associated with sleep disturbances. One class of neurodevelopmental disorders, the genetic synaptopathies, is caused by mutations in genes encoding proteins found at the synapse. Mutations in these genes cause derangement of synapse development and function. We utilized a validated sleep instrument, Childrenâs Sleep Habits Questionnaire (CSHQ) to examine the nature of sleep abnormalities occurring in individuals with two synaptopathiesâPhelanâMcDermid syndrome (PMD) (N = 47, male = 23, female = 24, age 1â46 years) and SYNGAP1-related intellectual disability (SYNGAP1-ID) (N = 64, male = 31, female = 33, age 1â64 years), when compared with unaffected siblings (N = 61, male = 25, female = 36, age 1â17 years). We found that both PMD and SYNGAP1-ID have significant sleep abnormalities with SYNGAP1-ID having greater severity of sleep disturbance than PMD. In addition, sleep disturbances were more severe for PMD in individuals 11 years and older compared with those less than 11 years old. Individuals with either disorder were more likely to use sleep aids than unaffected siblings. In conclusion, sleep disturbances are a significant phenotype in the synaptopathies PMD and SYNGAP1-ID. Improved sleep is a viable endpoint for future clinical trials for these neurodevelopmental disorders
Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2016
The aim of the survey was to provide on-going monitoring of the fish communities and abundance by boat electrofishing in the Ohau Channel, especially fish species that are taonga to Maori (tuna, or eels, morihana, or goldfish, and kĆura, or freshwater crayfish). In the current study, we present the findings from the tenth year of sampling (2016) and a summary of previous surveys
Prospective, multisite, international comparison of \u3csup\u3e18\u3c/sup\u3eF-fluoromethylcholine PET/CT, multiparametric MRI, and \u3csup\u3e68\u3c/sup\u3eGa-HBED-CC PSMA-11 PET/CT in men with high-risk features and biochemical failure after radical prostatectomy: Clinical performance and patient outcomes
A significant proportion of men with rising prostate-specific antigen (PSA) levels after radical prostatectomy (RP) fail prostate fossa (PF) salvage radiation treatment (SRT). This study was done to assess the ability of F-fluoromethylcholine ( F-FCH) PET/CT (hereafter referred to as F-FCH), Ga-HBED-CC PSMA-11 PET/CT (hereafter referred to as PSMA), and pelvic multiparametric MRI (hereafter referred to as pelvic MRI) to identify men who will best benefit from SRT. Methods: Prospective, multisite imaging studies were carried out in men who had rising PSA levels after RP, high-risk features, and negative/equivocal conventional imaging results and who were being considered for SRT. F-FCH (91/91), pelvic MRI (88/91), and PSMA (31/91) (Australia) were all performed within 2 wk. Imaging was interpreted by experienced local/central interpreters who were masked with regard to other imaging results, with consensus being reached for discordant interpretations. Expected management was documented before and after imaging, and data about all treatments and PSA levels were collected for 3 y. The treatment response to SRT was defined as a reduction in PSA levels of .50% without androgen deprivation therapy. Results: The median Gleason score, PSA level at imaging, and PSA doubling time were 8, 0.42 (interquartile range, 0.29â0.93) ng/mL, and 5.0 (interquartile range, 3.3â7.6) months. Recurrent prostate cancer was detected in 28% (25/88) by pelvic MRI, 32% (29/91) by F-FCH, and 42% (13/31) by PSMA. This recurrence was found within the PF in 21.5% (19/88), 13% (12/91), and 19% (6/31) and at sites outside the PF (extra-PF) in 8% (7/88), 19% (17/91), and 32% (10/31) by MRI, F-FCH, and PSMA, respectively (P, 0.004). A total of 94% (16/17) of extra-PF sites on F-FCH were within the pelvic MRI field. Intra-pelvic extra-PF disease was detected in 90% (9/10) by PSMA and in 31% (5/16) by MRI. F-FCH changed management in 46% (42/91), and MRI changed management in 24% (21/88). PSMA provided additional management changes over F-FCH in 23% (7/31). The treatment response to SRT was higher in men with negative results or disease confined to the PF than in men with extra-PF disease ( F-FCH 73% [32/44] versus 33% [3/9] [P, 0.02], pelvic MRI 70% [32/46] versus 50% [2/4] [P was not significant], and PSMA 88% [7/ 8] versus 14% [1/7] [P, 0.005]). Men with negative imaging results (MRI, F-FCH, or PSMA) had high (78%) SRT response rates. Conclusion: F-FCH and PSMA had high detection rates for extra-PF disease in men with negative/equivocal conventional imaging results and rising PSA levels after RP. These findings affected management and treatment responses, suggesting an important role for PET in triaging men being considered for curative SRT. 18 18 18 68 18 18 18 18 18 18 18 18 1
Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) â implications for incipient speciation in island freshwater fish species
Background: Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species.
Results: Microchemical analyses of otolith isotopes (Sr-88, Ba-137 and Ca-43) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes.
Conclusion: This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology, spawning timing, population genetics) yield congruent results, and provide clear and independent evidence for the existence of distinct migratory and non-migratory ecotypes within a river in a geographically confined range. The morphological changes within the non-migratory populations parallel interspecific patterns observed in all non-migratory New Zealand endemic Gobiomorphus species and other derived gobiid taxa, a pattern suggesting parallel evolution. This study indicates, for the first time, that distinct ecotypes of island freshwater fish species may be formed as a consequence of loss of migration and subsequent diversification. Therefore, if reproductive isolation persists, these processes may provide a mechanism to facilitate speciation
Short- and long- term effects of habitat fragmentation differ but are predicted by response to the matrix
Habitat loss and fragmentation are major threats to biodiversity and ecosystem
processes. Our current understanding of the impacts of habitat loss and fragmentation is based
largely on studies that focus on either short- term or long- term responses. Short- term responses
are often used to predict long- term responses and make management decisions. The lack of
studies comparing short- and long- term responses to fragmentation means we do not adequately
understand when and how well short- term responses can be extrapolated to predict long- term
responses, and when or why they cannot. To address this gap, we used data from one of the
worldâs longest- running fragmentation experiments, The Wog Wog Habitat Fragmentation
Experiment. Using data for carabid beetles, we found that responses in the long term (more
than 22 yr post- fragmentation â22 generations) often contrasted markedly with those in the
short term (5 yr post- fragmentation). The total abundance of all carabids, species richness and
the occurrence of six species declined in the short term in the fragments but increased over the
long term. The occurrence of three species declined initially and continued to decline, whilst
another species was positively affected initially but decreased in the long term. Speciesâ
responses to the matrix that surrounds the fragments strongly predicted both the direction
(increase/decline in occurrence) and magnitude of their responses to fragmentation.
Additionally, speciesâ responses to the matrix were somewhat predicted by their preferences for
different types of native habitat (open vs. shaded). Our study highlights the degree of the
matrixâs influence in fragmented landscapes, and how this influence can change over time. We
urge caution in using short- term responses to forecast long- term responses in cases where the
matrix (1) impacts speciesâ responses to fragmentation (by isolating them, creating new habitat
or altering fragment habitat) and (2) is likely to change through time.Funding to collect, process and identify samples between 2009 and 2013 was provided by
NSF DEB 0841892 to KFD and BAM. KFD was also supported by NSF DEB 1350872. MJE was funded by an Australian
National University PhD Scholarship
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