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1.
Behav Sci (Basel) ; 12(3)2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35323398

RESUMEN

The present study investigated the variation in higher education students' study burnout experiences and how they are related to academic success and social support needs. Similarities and differences between the international and domestic students were also explored. In this mixed-methods study, the data were collected through a self-reported questionnaire, and a total of 902 (response rate 42%) first year master's students from the fields of arts, business and technology responded. Using Latent Profile Analysis (LPA), we detected three distinct study burnout risk profiles (No exhaustion or cynicism; Exhausted; Exhausted and cynical). The following distinct forms of social support needs were found using theory-based qualitative content analysis: informational, instrumental, emotional, and co-constructional support. We found out that the students with highest risk of burnout had the lowest grade point averages (GPAs). Further investigation showed that international students pass their courses despite the experiences of study burnout, even though the GPAs might deteriorate. When the domestic students experience study burnout symptoms, they both gain fewer study credits and earn lower GPAs. Finally, a relationship between the form of support needed and the burnout profile was identified.

2.
J Exp Bot ; 59(5): 1013-21, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18325923

RESUMEN

Two species of thalloid liverworts, Blasia pusilla and Cavicularia densa, form stable symbioses with nitrogen-fixing cyanobacteria. Both bryophytes promote the persistence of their cyanobacterial associations by producing specialized gemmae, which facilitate the simultaneous dispersal of the host and its nitrogen-fixing symbionts. Here the genetic diversity of cyanobacterial symbionts of Blasia and Cavicularia is examined. The results indicate that the primary symbionts of both bryophytes are closely related and belong to a specific group of symbiotic Nostoc strains. Related strains have previously been reported from hornworts and cycads, and from many terricolous cyanolichens. The evolutionary origins of all these symbioses may trace back to pre-Permian times. While the laboratory strain Nostoc punctiforme PCC 73102 has been widely used in experimental studies of bryophyte-Nostoc associations, sequence-identical cyanobionts have not yet been identified from thalloid liverworts in the field.


Asunto(s)
Cianobacterias/genética , Hepatophyta/microbiología , Simbiosis , Secuencia de Bases , Cianobacterias/citología , Cianobacterias/aislamiento & purificación , Cianobacterias/fisiología , ADN Bacteriano/genética , Hepatophyta/fisiología , Intrones , Datos de Secuencia Molecular , Nostoc/genética , Nostoc/aislamiento & purificación , Reacción en Cadena de la Polimerasa , ARN Bacteriano/genética , ARN de Transferencia de Leucina/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Secuencias Repetidas en Tándem
3.
Biotechniques ; 42(4): 479-80, 482, 484-6, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17489235

RESUMEN

We have identified a fast and easy method for finding microsatellite markers that utilizes genome screening with inter-simple sequence repeat (ISSR) primers to detect microsatellite regions and to obtain sequence information flanking one side of the microsatellites and a restriction-ligation technique with a specific adaptor to allow sequence walking to obtain sequence information flanking the other side of the microsatellites. Two main alternatives of the method (with or without cloning) are presented. We successfully utilized the method when identifying microsatellite markers for 21 bryophyte species, three algal species, and for the raccoon dog. The proportion of polymorphic markers equaled 95%. We observed that microsatellites are commonly found within the sequenced ISSR amplification products (54% in the present study), in which case specific primers can be identified for the microsatellite without a further restriction-ligation step. It is evident that the DNA regions amplified by ISSR markers commonly represent microsatellite hotspots. We propose that the identified method and the knowledge of the common presence of additional microsatellite repeats within ISSR amplification products are especially attractive to researchers who conduct small-scale microsatellite identification, such as researchers in population genetics and conservation biology.


Asunto(s)
Genómica/métodos , Repeticiones de Microsatélite , Animales , Briófitas/genética , Chlorophyta/genética , Perros Mapache/genética , Rhodophyta/genética
4.
Forensic Sci Int ; 172(2-3): 161-3, 2007 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-17300893

RESUMEN

Two experiments were performed to test the relevance of bryophyte (Plantae, Bryophyta) material for forensic studies. The first experiment was conducted to reveal if, and how well, plant fragments attach to footwear in general. In the test, 16 persons walked outdoors wearing rubber boots or hiking boots. After 24h of use outdoors the boots were carefully cleaned, and all plant fragments were collected. Afterwards, all plant material was examined to identify the species. In the second experiment, fresh material of nine bryophyte species was kept in a shed in adverse conditions for 18 months, after which DNA was extracted and subjected to genotyping to test the quality of the material. Both experiments give support for the usability of bryophyte material in forensic studies. The bryophyte fragments become attached to shoes, where they remain even after the wearer walks on a dry road for several hours. Bryophyte DNA stays intact, allowing DNA profiling after lengthy periods following detachment from the original plant source. Based on these experiments, and considering the fact that many bryophytes are clonal plants, we propose that bryophytes are among the most usable plants to provide botanical evidence for forensic investigations.


Asunto(s)
Botánica/métodos , Briófitas , ADN de Plantas/aislamiento & purificación , Ciencias Forenses/métodos , Dermatoglifia del ADN/métodos , Ambiente , Brotes de la Planta , Zapatos
5.
J Forensic Sci ; 48(4): 804-7, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12877296

RESUMEN

Our study introduces the use of DNA fingerprinting of clonal plants in combination with phylogenetic and vegetation studies as a prospective forensic tool in criminal investigations. In this homicide case, the bryophyte species found on the suspects were identified as Brachythecium albicans, Calliergonella lindbergii, and Ceratodon purpureus. Colonies of all three species occurred at the crime site. DNA fingerprinting analyses were conducted for B. albicans and C. lindbergii, which were expected to reproduce mainly clonally, unlike C. purpureus, and included samples found on the suspects and samples collected from the crime site and other locations. It was concluded that B. albicans found on the suspects was likely to originate from the crime scene and that the sample of C. lindbergii may also have originated from the same site.


Asunto(s)
Bryopsida/clasificación , Bryopsida/genética , Dermatoglifia del ADN/métodos , ADN/aislamiento & purificación , Medicina Legal/métodos , Genes de Plantas , Adulto , Análisis por Conglomerados , Marcadores Genéticos , Homicidio , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo Genético
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