33 research outputs found

    Effects of cyanobacterial extracellular products and gibberellic acid on salinity tolerance in Oryza sativa L

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    Salt stress is one of the most serious factors limiting the productivity of rice, the staple diet in many countries. Gibberellic acid has been reported to reduce NaCl-induced growth inhibition in some plants including rice. Most paddy soils have a natural population of Cyanobacteria, prokaryotic photosynthethic microorganisms, which synthesize and liberate plant growth regulators such as gibberellins that could exert a natural beneficial effect on salt stressed rice plants. The aim of this work was to evaluate the effect of the cyanobacterium Scytonema hofmanni extracellular products on the growth of rice seedlings inhibited by NaCl and to compare it with the effect of the gibberellic acid in the same stress condition. Growth (length and weight of the seedlings) and biochemical parameters (5-aminolevulinate dehydratase activity, total free porphyrin and pigments content) were evaluated. Salt exposure negatively affected all parameters measured, with the exception of chlorophyll. Chlrorophyll concentrations nearly doubled upon exposure to high salt. Gibberellic acid counteracted the effect of salt on the length and dry weight of the shoot, and on carotenoid and chlorophyll b contents. Extracellular products nullified the salt effect on shoot dry weight and carotenoid content; partially counteracted the effect on shoot length (from 54% to 38% decrease), root dry weight (from 59% to 41% decrease) and total free porphyrin (from 31 to 13% decrease); reduced by 35% the salt increase of chlorophyll a; had no effect on root length and chlorophyll b. Gibberellic acid and extracellular products increased 5-aminolevulinate dehydratase activity over the control without salt. When coincident with high salinity, exposure to either EP or GA(3), resulted in a reversal of shoot-related responses to salt stress. We propose that Scytonema hofmanni extracellular products may counteract altered hormone homeostasis of rice seedlings under salt stress by producing gibberellin-like plant growth regulators

    "I have got something positive out of this situation": psychological benefits of caregiving in relatives of young people with muscular dystrophy.

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    This paper focuses on the psychological benefits of caregiving in key relatives of patients with muscular dystrophies (MD), a group of rare diseases characterized by progressive weakness and restriction of the patient's functional abilities. We describe whether relatives perceived caregiving to be a positive experience and test whether relatives' perceptions vary in relation to their view of the patient as a valued person, the degree of involvement in care, and the level of support provided by social network and professionals. The study sample included 502 key relatives of patients aged 4-25 years, suffering from Duchenne, Becker, or limb-girdle MD, in treatment for at least 6 months to one of the eight participating centers, living with at least one relative aged 18-80 years. Of key relatives, 88 % stated that they had gotten something positive out of the situation, 96 % considered their patients to be sensitive, and 94 % viewed their patients as talented. Positive aspects of caregiving were more recognized by key relatives who were more convinced that the patient was sensitive and who perceived that they received higher level of professional help and psychological social support. These results suggest that most key relatives consider that their caregiving experience has had a positive impact on their lives, despite the practical difficulties of caring for patients with MD. Professionals should help relatives to identify the benefits of caregiving without denying its difficulties. Clinicians themselves should develop positive attitudes towards family involvement in the care of patients with long-term diseases

    How authentic leadership influences team performance:the mediating role of team reflexivity

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    This study examines how authentic leadership influences team performance via the mediating mechanism of team reflexivity. Adopting a self-regulatory perspective, we propose that authentic leadership will predict the specific team regulatory process of reflexivity, which in turn will be associated with two outcomes of team performance; effectiveness and productivity. Using survey data from 53 teams in three organizations in the United Kingdom and Greece and controlling for collective trust, we found support for our stated hypotheses with the results indicating a significant fully mediated relationship. As predicted the self-regulatory behaviors inherent in the process of authentic leadership served to collectively shape team behavior, manifesting in the process of team reflexivity, which, in turn, positively predicted team performance. We conclude with a discussion of how this study extends theoretical understanding of authentic leadership in relation to teamwork and delineate several practical implications for leaders and organizations

    ANALISIS MUTU FISIK DAN CITARASA BEBERAPA VARIETAS KOPI ARABIKA GAYO AKIBAT PENUNDAAN PROSES PULPING

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    Selama abad terakhir ini pemanasan global yang terjadi berdampak terhadap peningkatan suhu. Dengan meningkatnya suhu, masa panen kopi menjadi lebih singkat. Singkatnya masa panen kopi memiliki masalah dikalangan petani karena kapasitas pemanenan yang meningkat dalam kurun waktu panen yang semakin pendek. Untuk mencapai pemanenan yang tepat waktu, petani biasanya cenderung lebih memilih menunda proses pulping karena kapasitas tenaga kerja yang terbatas. Penelitian ini bertujuan untuk mempelajari berapa lama waktu penundaan proses pulping yang masih bisa ditoleransi sehingga tidak terlalu berdampak pada mutu fisik dan citarasa yang dihasilkan dari beberapa varietas kopi. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) dengan pola faktorial yang terdiri atas 2 faktor. Faktor pertama adalah varietas kopi yang digunakan (V) yaitu V1 = Tim-tim, V2 = Bourbon dan V3 = Ateng Super. Faktor kedua adalah lama penundaan proses pulping yang dilakukan (P) yaitu P0 = 0 hari, P1 = 1 hari, P2 = 2 hari, P3 = 3 hari, P4 = 4 hari dan P5 = 5 hari. Setiap perlakuan diulang sebanyak dua kali sehingga terdapat 36 satuan percobaan. Analisis yang dilakukan meliputi: persentase buah mengapung, suhu buah selama penundaan proses pulping, densitas kamba, kadar air, biji busuk, biji hitam dan biji berwarna coklat. Serta pengujian pH seduhan kopi.Kata kunci : Kopi Arabika Gayo, mutu fisik,citarasa,penundaan proses pulping

    Small molecule activators of the Trk receptors for neuroprotection

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    The neurotophin signaling network is critical to the development and survival of many neuronal populations. Especially sensitive to imbalances in the neurotrophin system, cholinergic neurons in the basal forebrain are progressively lost in Alzheimer's disease. Therapeutic use of neurotrophins to prevent this loss is hampered, however, by a number of pharmacological challenges. These include a lack of transport across the blood-brain barrier, rapid degradation in the circulation, and difficulty in production. In this review we discuss the evidence supporting the neurotrophin system's role in preventing neurodegeneration and survey some of the pharmacological strategies being pursued to develop effective therapeutics targeting neurotrophin function
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