31 research outputs found
Direct Measurement of the Fermi Energy in Graphene Using a Double Layer Structure
We describe a technique which allows a direct measurement of the relative
Fermi energy in an electron system using a double layer structure, where
graphene is one of the two layers. We illustrate this method by probing the
Fermi energy as a function of density in a graphene monolayer, at zero and in
high magnetic fields. This technique allows us to determine the Fermi velocity,
Landau level spacing, and Landau level broadening in graphene. We find that the
N=0 Landau level broadening is larger by comparison to the broadening of upper
and lower Landau levels.Comment: 5 pages, 4 figure
Daya Hidup Spermatozoa Epididimis Kambing Peranakan Ettawa Yang Dipreservasi Dengan Pengencer Tris Dan Bberbagai Konsentrasi Maltosa
Cauda epididymal spermatozoa could be used as an alternative source of gamete in the application of various reproductive technologies, since the spermatozoa is motile and has ability for fertilizing the oocyte. Theobjective of this research was to examine the effectivity of maltose in maintaining viability of ettawa crossbreed goat epididymal spermatozoa preserved at 3–5oC. Five testis with epididymides of ettawa crossbreed goat were obtained from slaughterhouse. Epididymal spermatozoa was collected by the combination of slicing, flushing and tissues pressure of cauda epididymides with physiological saline (0.9% NaCl). Collected-spermatozoa wasdivided in equal volume into three tubes and diluted with Tris extender containing 20% egg yolk (control), Tris extender + 0.3 g maltose/100 ml (M0.3), and Tris extender + 0.6 g maltose/100 ml (M0.6), respectively. Dilutedspermatozoa was stored in refrigerator at 3–5oC. Quality of diluted-spermatozoa including percentages of motile spermatozoa (MS) and live spermatozoa (LS) were evaluated every day during storage at 3–5oC for four days. Data were analyzed using completely randomized design with three treatments and five replicates. Means were compared significant difference test at 0.05 significant level. Results of this study showed that mean spermatozoaconcentration, percentage of MS, percentage of LS, and percentage of abnormal spermatozoa of ettawa crossbreed goat fresh epididymal spermatozoa were 3,220 million cell/ml, 70%, 81%, and 4.3%, respectively. At day-5 of storage, percentages of MS and LS for M0.3 (38 and 60.4%) and M0.6 (38 and 57.2%) were significantly (P<0.05) higher than control (32 and 55.4%). In conclusion, addition of 0.3 and 0.6% maltose in Tris extender could be maintained viability of ettawa crossbreed goat epididymal spermatozoa preserved at 3–5oC forthree days
Acceptance and commitment therapy processes and their association with distress in cancer: a systematic review and meta-analysis
Around 42% of individuals with cancer experience distress. Acceptance and Commitment Therapy (ACT) can reduce distress, but effects are small, and mechanisms unclear. This review aimed to identify associations between ACT processes and distress in cancer. Search terms included cancer, ACT processes, self-compassion, and distress. Six online databases and grey literature were searched to March 2022. Of 6555 papers screened, 108 studies were included with a total of 17195 participants. Five meta-analyses of seventy-seven studies were conducted. Random effects meta-analyses of correlations revealed higher scores on flexible processes (acceptance, present moment awareness, self-compassion) were associated with lower distress (rpooled = -0.24, -0.39, -0.48, respectively); whilst higher scores on inflexible processes (experiential avoidance, cognitive fusion) were associated with higher distress (rpooled = 0.58, 0.57, respectively). Meta-analyses displayed moderate-to-high heterogeneity with most studies assessed as low risk of bias. Meta-regressions revealed no significant moderators (stage, time since diagnosis, gender and age). This review provides a theoretically aligned evidence base for associations between ACT processes and distress in cancer, supporting elements of ACT theory and providing targeted directions for intervention development. Due to limited evidence, future research should focus on the under-investigated processes (self-as-context, values, committed action) and conducting mediation analysis of ACT processes on distress in cancer in controlled trials
Understanding cycle tourism experiences at the Tour Down Under
Sport tourism experiences are subjective and emotional, laden with symbolic meaning. This study explores the experiences of participants who adopted the multiple roles of both an active participant and event spectator, within the parameters of one chosen sporting event. A professional cycling race event, the Tour Down Under in South Australia was chosen for this investigation, and 20 face-to-face individual interviews were conducted with cycle tourists. The three main themes emerging from the data were the interaction of people and temporary spaces on a sport tourism ‘stage’; the co-creation of authentic personal experiences and meanings; and identity reinforcement and the development of a sense of belonging. Consequently, a model for understanding sport event tourism experiences is proposed. The findings suggest that providing tourists with authentic and memorable experiences lies at the heart of what constitutes sport tourism. Whilst the results demonstrate that cycling events provide the individual with a sense of belonging or membership to a wider social group, they also illustrate that there is a continued need for more focused and nuanced approaches towards understanding sport tourism experiences that reflect the ever-increasing diversity and complexity of the interaction between sport, events and tourism
Reproductive Biology and Uniform Culture of Portulaca in Hawaii
Ten taxa of Portulaca that occur in Hawaii (P. lutea, P.
molokiniensis, P. oleracea, P. pi/osa, P. sclerocarpa, P. villosa, two imperfectly
known species, and two cultivars) were included in a study of reproductive
biology and uniform cultivation. The response of plants under uniform conditions
upholds the merger of the reputed Hawaiian endemic P. cyanosperma with
P. pilosa. All Portulaca taxa in Hawaii are autogamous, and in most instances
large numbers of seeds are set even when the flowers are totally undisturbed.
Some taxa are facultatively cleistogamous, but even in chasmogamous forms the
flowers are open for only about 3-9 hr. The cultivars were the only taxa observed
to attract pollinators, but P. molokiniensis, which was not studied in nature, appears
to have adaptations for biotic pollination. Most of the portulac as studied
have capsular fruit that require about 13-17 days to mature, but in P. sclerocarpa
the fruits are thick-walled and indehiscent and require about 28 days for maturation.
The life cycle ranges from about 8 weeks in most cases to several months in
P. molokiniensis. However, individuals of most taxa typically flower and fruit
man y times during one growing season. Seeds were generally nondormant, but
partial seed dormancy was encountered in P. molokiniensis
Small Interfering RNA–Mediated Translation Repression Alters Ribosome Sensitivity to Inhibition by Cycloheximide in \u3ci\u3eChlamydomonas reinhardtii\u3c/i\u3e
Small RNAs (sRNAs; approximately 20 to 30 nucleotides in length) play important roles in gene regulation as well as in defense responses against transposons and viruses in eukaryotes. Their biogenesis and modes of action have attracted great attention in recent years. However, many aspects of sRNA function, such as the mechanism(s) of translation repression at postinitiation steps, remain poorly characterized. In the unicellular green alga Chlamydomonas reinhardtii, sRNAs derived from genomeintegrated inverted repeat transgenes, perfectly complementary to the 39 untranslated region of a target transcript, can inhibit protein synthesis without or with only minimal mRNA destabilization. Here, we report that the sRNA-repressed transcripts are not altered in their polyadenylation status and they remain associated with polyribosomes, indicating inhibition at a postinitiation step of translation. Interestingly, ribosomes associated with sRNA-repressed transcripts show reduced sensitivity to translation inhibition by some antibiotics, such as cycloheximide, both in ribosome run-off assays and in in vivo experiments. Our results suggest that sRNA-mediated repression of protein synthesis in C. reinhardtii may involve alterations to the function/structural conformation of translating ribosomes. Additionally, sRNA-mediated translation inhibition is now known to occur in a number of phylogenetically diverse eukaryotes, suggesting that this mechanism may have been a feature of an ancestral RNA interference machinery