The Orbital Period of the Ultraluminous X-ray Source in M82

The ultraluminous x-ray source (ULX) in the galaxy M82 has been identified as a possible intermediate-mass black hole. We have found that the x-ray flux from M82 is modulated with a peak-to-peak amplitude corresponding to an isotropic luminosity of 2.4x10^40 erg/s in M82 and a period of 62.0 +/- 2.5 days, which we interpret as the orbital period of the ULX binary. This orbital period implies that the mass-donor star must be a giant or supergiant. Large mass-transfer rates, sufficient to fuel the ULX, are expected for a giant-phase mass donor in an x-ray binary. The giant phase has a short lifetime, indicating that we see the ULX in M82 in a brief and unusual period of its evolution.Comment: 3 pages, appeared in Scienc

Natural channel protein inserts and functions in a completely artificial, solid-supported bilayer membrane

Reconstitution of membrane proteins in artificial membrane systems creates a platform for exploring their potential for pharmacological or biotechnological applications. Previously, we demonstrated amphiphilic block copolymers as promising building blocks for artificial membranes with long-term stability and tailorable structural parameters. However, the insertion of membrane proteins has not previously been realized in a large-area, stable, and solid-supported artificial membrane. Here, we show the first, preliminary model of a channel membrane protein that is functionally incorporated in a completely artificial polymer, tethered, solid-supported bilayer membrane (TSSBM). Unprecedented ionic transport characteristics that differ from previous results on protein insertion into planar, free-standing membranes, are identified. Our findings mark a change in understanding protein insertion and ion flow within natural channel proteins when inserted in an artificial TSSBM, thus holding great potential for numerous applications such as drug screening, trace analyzing, and biosensing

Airy beam induced optical routing

We present an all-optical routing scheme based simultaneously on optically induced photonic structures and the Airy beam family. The presented work utilizes these accelerating beams for the demonstration of an all-optical router with individually addressable output channels. In addition, we are able to activate multiple channels at the same time providing us with an optically induced splitter with configurable outputs. The experimental results are corroborated by corresponding numerical simulations

Never an Alibi: The Dialogical Museum

https://digitalmaine.com/academic/1006/thumbnail.jp

Measuring Time Use in Surveys: How Valid Are Time Use Questions in Surveys? Concordance of Survey and Experience Sampling Measures

Since it is still unclear to what extent time allocation retrospectively reported in questionnaires, reflects people's actual behavior, examining the accuracy of responses to time use survey questions is of crucial importance. We analyze the congruence of time use information assessed through retrospective questionnaires and through experience sampling methodology. The sample comprised 433 individuals ranging in age from 14 to 86 years. Participants completed standard survey questions on time allocation. In addition, a mobile-phone based experience sampling technology was used over a period of three weeks to obtain snapshots of, on average, 54 momentary activities in which participants participated while pursuing their normal daily routines. Experience sampling assessments were scheduled six times a day over at least nine days, including workdays, Saturdays, andSundays. Results indicate that the congruence between time allocation assessed with survey questions (i.e. in SOEP) and time allocation assessed with experience sampling methodology depends on the characteristics of the respective activities. Associations between standard survey questions and experience sampling methods are quite substantial for long-lasting and externally structured activities, such as paid work on workdays. Incontrast, associations between survey and experience sampling methods are somewhat weaker, though highly statistically significant, for less externally structured, short-term and infrequent activities, such as errands, housework, and leisure. These moderate and relatively small correlations may indicate either an error-prone estimation of the prevalence of shortterm and infrequent activities by experience sampling or respondents' overrating of sporadic and short activities in survey questions. We conclude that activities with a long duration, such as paid work, can be measured in a satisfactory manner using short survey questions. Futureresearch is necessary to elucidate which method (experience sampling method or survey questions) delivers more reliable and valid measures for shortterm and sporadic activities.Day Reconstruction Methods (DRM) should be included in this future methodological research.Survey methods, experience sampling method, validity, time use, market work, housework, leisure, German Socio-Economic Panel Study, MMAA, SOEP

High maternal androstenedione levels during pregnancy in a small precocial mammal with female genital masculinisation

-Masculinisation of female genitalia is an intriguing phenomenon amongst some mammalian species and its endocrinological basis as well as its adaptive value is still heavily debated. We recently reported female genital masculinisation in Cavia magna. The closely related C. aperea, does not show such masculinisation providing an unique opportunity to investigate potential endocrinological mechanisms underlying this difference. For both species we determined plasma levels of androstenedione and testosterone in adults of both sexes, and in females during different stages of pregnancy. Consistent with the normal mammalian pattern males showed higher levels of both androgens than conspecific females. Androgen profiles during pregnancy differed significantly between C. magna and C. aperea females: during mid-pregnancy androstenedione levels were strongly elevated in the masculinised C. magna, but not in C. aperea, indicating that high levels of this androgen may be involved in the differentiation of masculinized genitalia in female C. magna, as has been suggested for the spotted hyena. In both C. magna and the spotted hyena the pups show a highly advanced state of maturation, but in contrast to the hyena female C. magna are not overly aggressive. We therefore propose that female genital masculinisation might be a side effect of early exposure to elevated levels of maternal androgens that might be selected for to speed up precocial development.

Impact of modified atmosphere and humidity packaging on the quality, off-odour development and volatiles of ‘Elsanta’ strawberries

Development of off-odours, as well as visual quality of packaged fresh produce plays a crucial role in consumer’s choice. In this context, this work investigated the odour profile, condensation, gas composition, and postharvest quality attributes of strawberries stored under modified atmosphere and humidity packaging at 5 °C for 14 days. The packages were fitted with fixed area (69, 126.5, and 195.5 cm2) of different permeable membranes (NatureFlex, Xtend, and Propafilm). No significant changes were detected on the measured physicochemical quality attributes of strawberries and mass loss was below 1.5% across the different packaging systems. Package modification/design had an influence on in-package water vapour condensation, gas composition, and accumulation of secondary volatile organic compounds (acetaldehyde, acetone, ethanol and ethyl acetate)

Transpiration and moisture evolution in packaged fresh horticultural produce and the role of integrated mathematical models: A review

Transpiration has various adverse effects on postharvest quality and the shelf-life of fresh fruit and vegetables (FFV). If not controlled, the water released through this process results in direct mass loss and moisture condensation inside packaged FFV. Condensation represents a threat to the product quality as water may accumulate on the product surface and/or packaging system, causing defects in external appearance and promoting growth of spoilage microorganisms. Thus, moisture regulation is extremely important for extending FFV shelf-life. This review focuses on transpiration phenomenon and moisture evolution in packaged fresh horticultural produce. It provides recent information on various moisture control strategies suitable for packaging of fresh horticultural produce. It also provides an evaluation on the role and application of integrative mathematical modelling in describing water relations of FFV for packaging design, as well as, an overview of models reported in literature

The Saccharomyces cerevisiae Mob2p-Cbk1p kinase complex promotes polarized growth and acts with the mitotic exit network to facilitate daughter cell-specific localization of Ace2p transcription factor.

The Saccharomyces cerevisiae mitotic exit network (MEN) is a conserved signaling network that coordinates events associated with the M to G1 transition. We investigated the function of two S. cerevisiae proteins related to the MEN proteins Mob1p and Dbf2p kinase. Previous work indicates that cells lacking the Dbf2p-related protein Cbk1p fail to sustain polarized growth during early bud morphogenesis and mating projection formation (Bidlingmaier, S., E.L. Weiss, C. Seidel, D.G. Drubin, and M. Snyder. 2001. Mol. Cell. Biol. 21:2449-2462). Cbk1p is also required for Ace2p-dependent transcription of genes involved in mother/daughter separation after cytokinesis. Here we show that the Mob1p-related protein Mob2p physically associates with Cbk1p kinase throughout the cell cycle and is required for full Cbk1p kinase activity, which is periodically activated during polarized growth and mitosis. Both Mob2p and Cbk1p localize interdependently to the bud cortex during polarized growth and to the bud neck and daughter cell nucleus during late mitosis. We found that Ace2p is restricted to daughter cell nuclei via a novel mechanism requiring Mob2p, Cbk1p, and a functional nuclear export pathway. Furthermore, nuclear localization of Mob2p and Ace2p does not occur in mob1-77 or cdc14-1 mutants, which are defective in MEN signaling, even when cell cycle arrest is bypassed. Collectively, these data indicate that Mob2p-Cbk1p functions to (a) maintain polarized cell growth, (b) prevent the nuclear export of Ace2p from the daughter cell nucleus after mitotic exit, and (c) coordinate Ace2p-dependent transcription with MEN activation. These findings may implicate related proteins in linking the regulation of cell morphology and cell cycle transitions with cell fate determination and development

Moisture absorption kinetics of FruitPad for packaging of fresh strawberry

This study analysed the moisture absorption kinetics of FruitPad embedded with different concentrations of fructose with further application of such pads in packaging of fresh strawberries. The FruitPad was exposed to different storage conditions (temperature and RH) and moisture absorption kinetics was gravimetrically determined over 5 days of storage. FruitPad with 30% fructose showed highest amount of moisture absorption (0.94 g of water/g of pad) at 20 °C and 100% RH. The Weibull model combined with the Flory-Huggins model adequately described changes in moisture content of the FruitPad with respect to storage time and humidity (R2 = 93–96%). The FruitPad containing fructose minimized in-package condensation compared to the pad without fructose. Weight loss of packaged strawberry was less than 0.9% which was much below the acceptable limit of 6% for strawberry