Lars Bjork

Lars Bjork
Uppsala University | UU · Department of Organismal Biology

Ph.D

About

40
Publications
6,515
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1,717
Citations

Publications

Publications (40)
Article
Full-text available
Essential oils of Hyptis suaveolens (Lamiaceae), Croton roxburghii (Euphorbiaceae), and Litsea cubeba (Lauraceae) were tested in the field near Vientiane city, Lao PDR, on humans for repellent activity against mosquitoes. Landing mosquitoes were collected and later identified. The most abundant mosquitoes captured belonged to the genera Armigeres,...
Article
Full-text available
Medicinal plant trade is important for local livelihoods. However, many medicinal plants are difficult to identify when they are sold as roots, powders or bark. DNA barcoding involves using a short, agreed-upon region of a genome as a unique identifier for species- ideally, as a global standard. What is the functionality, efficacy and accuracy of t...
Data
Full-text available
RAxML phylogram of the rpoC1 extended reference dataset plus the market rpoC1 sequences. (PDF)
Data
Blastclust output rpoC1. (TXT)
Data
Blastclust output psbA-trnH. (TXT)
Data
Blastclust output ITS. (TXT)
Article
Medicinal plant traditional knowledge is one of the most widely known traditional ecosystem services, as it provides primary healthcare, contributes to subsistence livelihoods, and for its potential value as a source of novel pharmaceuticals. People living in close contact with their surroundings for many generations are hypothesized to have develo...
Article
Full-text available
Fundamental in traditional postpartum recovery in Lao PDR is the use of hotbeds, mother roasting, steam sauna and steam baths. During these treatments medicinal plants play a crucial role, but little has been published about how the treatments are carried out precisely, which species are used, the medicinal properties of these species, and the medi...
Article
Full-text available
Activities and diet during the postpartum period are culturally dictated in many Southeast Asian cultures, and a period of confinement is observed. Plants play an important role in recovery during the postpartum period in diet and traditional medicine. Little is known of the Kry, a small ethnic group whose language was recently described, concernin...
Article
Full-text available
Hematophagous parasites such as leeches, ticks, mites, lice, bedbugs, mosquitoes, and myiasis-producing fly larvae are common health problems in Lao People's Democratic Republic. Several arthropod-borne infections, e.g., malaria, dengue fever, and Japanese encephalitis, are endemic there. Effective vector control methods including the use of pestic...
Article
Proteomic screening of strawberry (Fragaria ananassa) yielded a 58% success rate in protein identification in spite of the fact that no genomic sequence is available for this species. This was achieved by a combination of MALDI-MS/MS de novo sequencing of double-derivatized peptides and indel-tolerant searching against local protein databases built...
Article
No strawberry allergen has so far been identified and characterized. Serum samples were collected from patients with a suggestive case history of adverse reactions to strawberry and other fruits. Extracts from fresh and frozen strawberries were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting and m...
Article
A nasal spray formulation containing an extract of Artemisia abrotanum L. was developed for therapeutic use in patients with allergic rhinitis and other upper airway disorders. The nasal spray preparation used contains a mixture of essential oils (4 mg/ml) and flavonols (2.5 microg/ml), of which some components have been shown to possess antiinflam...
Article
To induce variation in a valerian, Valeriana officinalis L., selected plant materials were cultured in vitro. Plants were successfully regenerated from callus and these regenerated plants had large variations in height and root weight. Some of the regenerated plants had improved chemical composition, a higher concentration of valerenic acid derivat...
Article
Rosehip extracts of 18 samples representing six taxa in the genus Rosa were evaluated for antioxidant activities by use of different test systems. The ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) of the crude extracts ranged from 983.4 to 2187.1 µmol FRAP g−1 dry matter and from 457.2 to 626.2 µmol TEAC...
Article
The contents of low-molecular-weight carbohydrates (LMWC; sorbitol, glucose, fructose and sucrose), starch, dietary fibre and organic acids were determined in seven apple cultivars at the start and end of the consumption interval. The cultivars included were Summered, Aroma, Ingrid Marie, Cox Orange, Mutzu, Belle de Boskoop and Jonagold. The total...
Article
Different fractions of sea buckthorn fruits were investigated for antioxidant activity and its relationship to different phytonutrients. Capacity to scavenge radicals of the crude extract, like the phenolic and ascorbate extracts, decreased significantly with increased maturation. The changes were strongly correlated with the content of total pheno...
Article
To investigate the variations of active compounds between species, varieties and individuals of Valeriana cultivated under the same environmental condition, the contents of valerenic acid derivatives and valepotriates in rhizomes and roots of different plant material were analysed by a HPLC method. Different species or varieties of Valeriana yielde...
Article
Cybrids with nuclei of Nicotiana tabacum and chloroplasts from Petunia hybrida in general accumulate higher amounts of nicotine and (1S,2E,4R,6R,7E,11E)-and(1S,2E,4S,6R,7E,11E)-2,7,11-cembratriene-4,6-diol than do ordinary tobacco plants. The composition of the cembranic diterpenoids present in the cuticular wax of the cybrid leaves, was, with one...
Article
Elicitors did not stimulate the accumulation of ginsenosides in P. ginseng tissue cultures. Mevalonic acid (MVA) increased the accumulation of ginsenosides with 38%. Addition of elicitors together with MVA inhibited the increase. The uptake of MVA in presence of elicitors was reduced. MVA added in early log phase was predominantly incorporated into...
Article
Five differentiated strains of Panax ginseng were established and their growth, ginsenoside accumulation and ginsenoside distribution were studied when grown in light as well as in darkness. Individual growth parameters were obtained for each strain. A maximal growth index value of 5.5 within a cultivation period of 4 weeks was obtained with strain...
Article
Differentiated cultures of Panax ginseng were grown various carbon sources. The effects on growth, ginsenoside accumulation, sugar uptake and enzyme activities were investigated. The responses were dependent on the degree of differentiation. A root culture had an optimal biomass production grown on 30 g1−1 sucrose and a maximal ginsenoside content...
Article
Low concentrations of chloramphenicol (10−8 and 10−7 mol 1−1) and of 3-aminotriazol (10−6 and 10−5 mol 1−1) reduced the accumulation of cardenolides in illuminated somatic embryos (stage-II-globules and late embryo structures) of D. lanata more than that of chlorophylls. In contrast norflurazon (10−6 and 10−5 mol 1-−1) repressed chlorophyll synthes...
Article
Seeds from Panax ginseng S. A. Meyer and Panax pseudoginsengWall. were used as starting material for tissue cultures. To achieve callus growth and shoot formation the seeds were surface sterilized and cut into 2–3 pieces. For Panax ginseng pretreatment with gibberellic acid was necessary to obtain growth. The pieces were placed on modified MS agar...
Article
Digitalis lanata cell cultures grown as small undifferentiated aggregates in suspension culture can be redifferentiated into green embryos that produce cardenolides. The possibility of using a statistical (Box-Wilson) experimental design to study the effects of four different variables on growth, differentiation, and cardenolide production of D. la...
Article
Effects of GA3 (gibberellic acid) on growth of and cardenolide accumulation in Digitalis lanata tissue cultures are reported. Two cardenolide-producing strains were compared. Strain S-1, which accumulated cardenolides predominantly in light, showed increased growth but decreased cardenolide content after cultivation with GA3 in the medium. Strain S...
Article
The active ingredient of the fungicide ‘Panoctine’ is a standardised mixture of guanidated amine acetates (GTA). This mixture was degraded in German standard soils with half-lives of 400–600 days. GTA dressed on to wheat seed at 0.75 g kg− had a half-life of 20 days when seed was incubated in Petri dishes at 25°C and of 80 days on seed sown in pots...
Article
The influence of light on the accumulation of cardenolides by Digitalis lanata S-1 was studied. Optimal radiant flux for chlorophyll accumulation w
Article
VI Int. Congr. Plant Tissue and Cell Culture. Minnesota, 3 - 8 Aug. 1986, 245

Questions

Question (1)
Question
I have a student who during long time has studied the moths in central Laos. She also document them from larvae to butterfly. She speaks English and is looking for possibilities to make a bachelor and master in the field og environment/biodiversity.
kind regards
Lars Bjork

Projects

Projects (2)