383 research outputs found
Social Support and Self-Efficacy on Turnover Intentions: The Mediating Role of Conflict and Commitment
Turnover intentions are a phenomenon that affects the life of organizations and causes highly negative consequences. Based on previous studies, it is possible to consider antecedents to turnover in terms of both individual and social perceived resources, which previous research does not usually examine simultaneously. The aim of this study was to explore the role of both resources (individual and social) on turnover intentions. Thus, we hypothesized that perceived social support and self-efficacy have an impact on turnover intentions and that this relationship is mediated by interpersonal conflict and Affective Commitment. A total of 392 Italian employees completed a self-report questionnaire. A structural equation model was tested. The results showed that interpersonal conflict and Affective Commitment fully mediated the relationship between social support, self-efficacy and turnover intentions. Practical implications are discussed
Proactive, boundaryless, and confident graduates entering the labour market: does need for cognitive closure play a role as a moderator?
The university to work transition is a crucial and delicate stage for graduates, as it involves an essential change of role. Previous studies have shown that proactive personality, boundaryless mind-set and career self-efficacy are critical variables for a successful labour market integration/entry. This study analyzes the involvement of the need for cognitive closure as an individual variable that can both favor and hinder this process. Specifically, this work examines the moderating role of need for cognitive closure in the indirect association between proactive personality and career self-efficacy through boundaryless mind-set in a sample of 762 adults enrolled at the university or recently graduated therein. Results showed that career self-efficacy was positively predicted by proactive personality and boundaryless mind-set. Although a significant indirect effect was present thus confirming our first hypothesis, it did not vary depending on the need for cognitive closure proving that need for cognitive closure did not act as a moderator of this indirect association, hence not supporting our second hypothesis. These findings were discussed concerning the complexity of
students’ choices in transition and the nature of the information processing process needed for those choices
Precise Stellar Radial Velocities of an M Dwarf with a Michelson Interferometer and a Medium-resolution Near-infrared Spectrograph
Precise near-infrared radial velocimetry enables efficient detection and
transit verification of low-mass extrasolar planets orbiting M dwarf hosts,
which are faint for visible-wavelength radial velocity surveys. The TripleSpec
Exoplanet Discovery Instrument, or TEDI, is the combination of a variable-delay
Michelson interferometer and a medium-resolution (R=2700) near-infrared
spectrograph on the Palomar 200" Hale Telescope. We used TEDI to monitor GJ
699, a nearby mid-M dwarf, over 11 nights spread across 3 months. Analysis of
106 independent observations reveals a root-mean-square precision of less than
37 m/s for 5 minutes of integration time. This performance is within a factor
of 2 of our expected photon-limited precision. We further decompose the
residuals into a 33 m/s white noise component, and a 15 m/s systematic noise
component, which we identify as likely due to contamination by telluric
absorption lines. With further development this technique holds promise for
broad implementation on medium-resolution near-infrared spectrographs to search
for low-mass exoplanets orbiting M dwarfs, and to verify low-mass transit
candidates.Comment: 55 pages and 13 figures in aastex format. Accepted by PAS
Ten-fold spectral resolution boosting using TEDI at the Mt. Palomar NIR Triplespec spectrograph
An optical technique called "interferometric spectral reconstruction" (ISR) is capable of increasing a spectrograph's resolution and stability by large factors, well beyond its classical limits. We have demonstrated a 6- to 11-fold increase in the Triplespec effective spectral resolution (R=2,700) to achieve R=16,000 at 4100 cm-^(1) to 30,000 at 9600 cm^(-1) by applying special Fourier processing to a series of exposures with different delays (optical path differences) taken with the TEDI interferometer and the near-infrared Triplespec spectrograph at the Mt. Palomar Observatory 200 inch telescope. The TEDI is an externally dispersed interferometer (EDI) used for Doppler radial velocity measurements on M-stars, and now also used for ISR. The resolution improvement is observed in both stellar and telluric features simultaneously over the entire spectrograph bandwidth (0.9-2.45 ÎĽm). By expanding the delay series, we anticipate achieving resolutions of R=45,000 or more. Since the delay is not continuously scanned, the technique is advantageous for measuring time-variable phenomena or in varying conditions (e.g. planetary fly-bys). The photon limited signal to noise ratio can be 100 times better than a classic Fourier Transform Spectrometer (FTS) due to the benefit of dispersion
Optimum time for hand pollination in yam (Dioscorea spp.)
Open Access Journal; Published online: 18 Aug 2022Hand pollination success rate is low in yam (Dioscorea spp.), due partly to suboptimal weather conditions. Thus, determining the most suitable time for pollination could improve the pollination success in yam breeding programs. We performed continuous hand pollination within flowering windows of D. rotundata and D. alata for two consecutive years to determine the most appropriate month, week, and hours of the day allowing maximum pollination success. In D. alata crossing block, we observed significant differences among crossing hours for pollination success (p = 0.003); morning hours (8–12 a.m.) being more conducive than afternoons (12–5 p.m.). No significant differences existed between crossing hours in D. rotundata, though the mid-day seemed optimal. For both species, the time interval 11–12 a.m. was more appropriate for crossing while 4–5 p.m. was the poorest. However, in vitro pollen germination tests showed that mid-day pollen collection (12 noon–2 p.m.) had better results than both extremes, though there were strong genotypic effects on outcomes. Pollination success rates differed significantly among months for D. alata (p 0.05). Differences in pollination success existed across weeks within flowering windows of both D. alata (p < 0.001) and D. rotundata (p = 0.004). The seed production efficiency (SPE) had a similar trend as the pollination success rate. No clear pattern existed between the pollination time and the seed setting rate (SSR) or seed viability (SV), though their dynamics varied with weeks and months. This study provided an insight on the dynamics of pollination outcomes under the influence of pollination times and allows detecting months, weeks, and hours of the day when hybridization activities should be focused for better results
Genome-wide association studies for sex determination and cross-compatibility in water yam (Dioscorea alata L.)
Open Access Journal; Published online: 10 Jul 2021Yam (Dioscorea spp.) species are predominantly dioecious, with male and female flowers
borne on separate individuals. Cross-pollination is, therefore, essential for gene flow among and
within yam species to achieve breeding objectives. Understanding genetic mechanisms underlying
sex determination and cross-compatibility is crucial for planning a successful hybridization
program. This study used the genome-wide association study (GWAS) approach for identifying
genomic regions linked to sex and cross-compatibility in water yam (Dioscorea alata L.). We identified
54 markers linked to flower sex determination, among which 53 markers were on chromosome 6 and
one on chromosome 11. Our result ascertained that D. alata is characterized by the male heterogametic
sex determination system (XX/XY). The cross-compatibility indices, average crossability rate (ACR)
and percentage high crossability (PHC), were controlled by loci on chromosomes 1, 6 and 17. Of
the significant loci, SNPs located on chromosomes 1 and 17 were the most promising for ACR and
PHC, respectively, and should be validated for use in D. alata hybridization activities to predict
cross-compatibility success. A total of 61 putative gene/protein families with direct or indirect
influence on plant reproduction were annotated in chromosomic regions controlling the target traits.
This study provides valuable insights into the genetic control of D. alata sexual reproduction. It
opens an avenue for developing genomic tools for predicting hybridization success in water yam
breeding programs
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