WorldWideScience

Sample records for lepidium draba populations

  1. Phenology and temperature-dependent development of Ceutorhynchus assimilis, a potential biological control agent for Lepidium draba

    Science.gov (United States)

    Heart-podded hoary cress (Lepidium draba) is an alien weed that has invaded rangeland in the northwestern USA. A host race (i;e; host-specific biotype) of the weevil, Ceutorhynchus assimilis, is being evaluated as a prospective biological control agent. This biotype is only known from southern Eur...

  2. ALLELOPATHIC EFFECT OF PARSLEY (Petroselinum crispum Mill. COGERMINATION, WATER EXTRACTS AND RESIDUES ON HOARY CRESS (Lepidium draba (L. Desv.

    Directory of Open Access Journals (Sweden)

    Marija Ravlić

    2014-06-01

    Full Text Available The aim of the study was to examine allelopathic effect of parsley (Petroselinum crispum Mill. on germination and growth parameters of weed species hoary cress (Lepidium draba (L. Desv.. Cogermination of hoary cress with parsley seeds, water extracts from fresh and dry parsley biomass in concentrations of 5 and 10% (50 and 100 g per litre of distilled water were evaluated in Petri dishes. Effect of water extracts from fresh parsley biomass in aforementioned concentrations as well as effects of fresh and dry parsley residues in two rates (10 and 20 g/kg of soil were examined in pots with soil. Cogermination of seeds stimulated root length, but decreased shoot length and fresh weight of hoary cress seedlings. In the Petri dish assay, extracts from fresh and dry parsley biomass reduced germination of hoary cress, but had both stimulatory as well as inhibitory effect on other parameters. The highest concentration of dry biomass extract completely reduced germination rate of hoary cress (by 100%. In the pot experiment, extracts from fresh parsley biomass had stimulatory effect on weed growth parameters except for root length which was inhibited with higher concentration by 4.2%. Fresh parsley residues reduced germination, root and shoot length of hoary cress, while dry parsley residues promoted measured parameters, with the exception of root length.

  3. Phytotoxical effect of Lepidium draba L. extracts on the germination and growth of monocot (Zea mays L.) and dicot (Amaranthus retroflexus L.) seeds.

    Science.gov (United States)

    Kaya, Yusuf; Aksakal, Ozkan; Sunar, Serap; Erturk, Filiz Aygun; Bozari, Sedat; Agar, Guleray; Erez, Mehmet Emre; Battal, Peyami

    2015-03-01

    Laboratory experiments were performed to determine phytotoxic potentials of white top (Lepidium draba) methanol extracts (root, stem and leaf) on germination and early growth of corn (Zea mays) and redroot pigweed (Amaranthus retroflexus). Furthermore, the effects of different methanol extracts of L. draba on the phytohormone (indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin) levels of corn and redroot pigweed were investigated. It was observed that all concentrations of methanol extracts of root, stem and leaf of L. draba inhibited germination, radicle and plumule elongation when compared with the respective controls. Besides this, the degree of inhibition was increased in concert with increasing concentrations of extracts used. On the other hand, phytohormone levels changed with the application of different extract concentrations. Comparing with the control, the GA levels significantly decreased while the ABA levels increased in all the application groups. Zeatin and IAA levels showed changes depending upon the applied extracts and concentrations. © The Author(s) 2012.

  4. Spatial relationships between seed bank and seedling populations of Hordeum spontaneum and Cardaria draba in saffron (Crocus sativus L. fields

    Directory of Open Access Journals (Sweden)

    hasan makariyan

    2009-06-01

    Full Text Available Geostatistical techniques were used to characterize the spatial relationship between Hordeum spontaneum and Cardaria draba seedling and seed bank over the course of one growing season (2004-2005 in three saffron fields, located in Southern Khorasan, Iran. The density and spatial distribution of weeds varied widely with fields. The emergence percentage was higher for Cardaria draba than for H. spontaneum in all fields. Semivariograms showed spatial autocorrelation in seed bank and seedling populations of H. spontaneum and C. draba in all fields. Cross-semivariograms showed moderate to strong (63.3 to 94.7% and strong spatial continuity (78.4 to 95.4 %. between seed bank and seedling population densities of H. spontaneum and C. draba, respectively. Grey-scale field maps of C. draba seed banks corresponded visually to maps of seedling populations and could have been used to target control efforts, but visual correspondence between H. spontaneum seed bank and seedling maps was poor. Seed bank and seedling mapping may be useful for site-specific management, but additional information is needed to understand variation in the relationships between these two populations over time and space.

  5. New Lepidium (Brassicaceae) from New Zealand

    Science.gov (United States)

    de Lange, P. J.; Heenan, P. B.; Houliston, G. J.; Rolfe, J. R.; Mitchell, A. D.

    2013-01-01

    Abstract A revision of the New Zealand endemic Lepidium oleraceum and allied species is presented. Sixteen species are recognised, 10 of these are new. The new species are segregated on the basis of morphological characters supported by molecular data obtained from three DNA markers (two rDNA and one cpDNA). One species, Lepidium castellanum sp. nov., is endemic to the Kermadec Islands where it is sympatric with Lepidium oleraceum. The North Island of New Zealand supports four species, with two of them, Lepidium amissum sp. nov. and Lepidium obtusatum, now extinct. The South Island supports six species, that, aside from Lepidium banksii, Lepidium flexicaule and Lepidium oleraceum, are all confined to the south-eastern half of the island (Lepidium aegrum sp. nov., Lepidium crassum sp. nov. and Lepidium juvencum sp. nov.). One of these, Lepidium juvencum sp. nov., extends to Stewart Island. The Chatham Islands support six species (Lepidium flexicaule, Lepidium oblitum sp. nov., Lepidium oleraceum, Lepidium oligodontum sp. nov., Lepidium panniforme sp. nov., and Lepidium rekohuense sp. nov.), one of which, Lepidium oligodontum sp. nov., extends to the Antipodes Islands group. The remote, subantarctic Bounty Islands group supports one endemic, Lepidium seditiosum sp. nov., which is the only vascular plant to be recorded from there. Lepidium limenophylax sp. nov. is known from islands off the south-western side of Stewart Island/Rakiura, The Snares and Auckland islands. Lepidium naufragorum, although not related to Lepidium oleraceum and its allies, is also treated because populations with entire leaves are now known. Typification is undertaken for Lepidium banksii, Lepidium oleraceum, Lepidium oleraceum var. acutidentatum, var. frondosum and var. serrulatum. PMID:23794938

  6. Ameliorative effect of Draba nemorosa extract on chronic heart ...

    African Journals Online (AJOL)

    1Department of Cardiology, The Second People's Hospital of Huai'an, 2Pediatric Surgery, Huai'an Maternity and Children ... treating cardiovascular diseases. This study was aimed at investigating the effect of DNE on CHF in a rat model. EXPERIMENTAL. Materials. Draba nemorosa ... Drug administration began from.

  7. Ameliorative effect of Draba nemorosa extract on chronic heart ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of Draba nemorosa extract (DNE) on oxidative stress and hemodynamics in rats with chronic congestive heart failure (CHF). Methods: Adriamycin was used to establish CHF in Sprague Dawley (SD) rat model. Six groups of SD rats were used in this study: control group, CHF group, captopril ...

  8. Genetics of cryptic speciation within an Arctic mustard, Draba nivalis.

    Directory of Open Access Journals (Sweden)

    A Lovisa S Gustafsson

    Full Text Available Crossing experiments indicate that hybrid sterility barriers frequently have developed within diploid, circumpolar plant species of the genus Draba. To gain insight into the rapid evolution of postzygotic reproductive isolation in this system, we augmented the linkage map of one of these species, D. nivalis, and searched for quantitative trait loci (QTLs associated with reproductive isolation. The map adds 63 new dominant markers to a previously published dataset of 31 co-dominant microsatellites. These markers include 52 amplified fragment length polymorphisms (AFLPs and 11 sequence-specific amplified polymorphisms (SSAPs based on retrotransposon sequence. 22 markers displaying transmission ratio distortion were further included in the map. We resolved eight linkage groups with a total map length of 894 cM. Significant genotype-trait associations, or quantitative trait loci (QTL, were detected for reproductive phenotypes including pollen fertility (4 QTLs, seed set (3 QTLs, flowering time (3 QTLs and number of flowers (4 QTLs. Observed patterns of inheritance were consistent with the influence of both nuclear-nuclear interactions and chromosomal changes on these traits. All seed set QTLs and one pollen fertility QTL displayed underdominant effects suggestive of the involvement of chromosomal rearrangements in hybrid sterility. Interestingly, D. nivalis is predominantly self-fertilizing, which may facilitate the establishment of underdominant loci and contribute to reproductive isolation.

  9. New Lepidium (Brassicaceae from New Zealand

    Directory of Open Access Journals (Sweden)

    Peter de Lange

    2013-06-01

    Full Text Available A revision of the New Zealand endemic Lepidium oleraceum and allied species is presented. Sixteen species are recognised, 10 of these are new. The new species are segregated on the basis of morphological characters supported by molecular data obtained from three DNA markers (two rDNA and one cpDNA. One species, L. castellanum sp. nov., is endemic to the Kermadec Islands where it is sympatric with L. oleraceum. The North Island of New Zealand supports four species, with two of them, L. amissum sp. nov. and L. obtusatum, now extinct. The South Island supports six species, that, aside from L. banksii, L. flexicaule and L. oleraceum, are all confined to the south-eastern half of the island (L. aegrum sp. nov., L. crassum sp. nov. and L. juvencum sp. nov.. One of these, L. juvencum sp. nov., extends to Stewart Island. The Chatham Islands support six species (L. flexicaule, L. oblitum sp. nov., L. oleraceum, L. oligodontum sp. nov., L. panniforme sp. nov., and L. rekohuense sp. nov., one of which, L. oligodontum sp. nov., extends to the Antipodes Islands group. The remote, subantarctic Bounty Islands group supports one endemic, L. seditiosum sp. nov., which is the only vascular plant to be recorded from there. Lepidium limenophylax sp. nov. is known from islands off the south-western side of Stewart Island/Rakiura, The Snares and Auckland islands. Lepidium naufragorum, although not related to L. oleraceum and its allies, is also treated because populations with entire leaves are now known. Typification is undertaken for L. banksii, L. oleraceum, L. oleraceum var. acutidentatum, var. frondosum and var. serrulatum.

  10. Lepidium flavum Torrey var. apterum nob

    NARCIS (Netherlands)

    Henrard, J.Th.; Thellung, A.

    1918-01-01

    Wie bekannt, ist TORREY’S Lepidium flavum sehr ausgezeichnet durch die gelbe Krone mit der zweizähnigen Frucht und dem sehr langen hervorragenden Griffel *). Lepidium flavum gehört also zur Sektion Monoploca (BUNGE 1845 pro gen.) THELLUNG, und zwar speziell zur Grex Alyssoidea THELL. ¹) Bei einer

  11. Role of maca (Lepidium meyenii) consumption on serum interleukin-6 levels and health status in populations living in the Peruvian Central Andes over 4000 m of altitude.

    Science.gov (United States)

    Gonzales, Gustavo F; Gasco, Manuel; Lozada-Requena, Ivan

    2013-12-01

    Lepidium meyenii (Maca) is a plant that grows at over 4,000 m above sea level in the central Peruvian Andes. The hypocotyls of this plant are traditionally consumed for their nutritional and medicinal properties. The aim of this study was to determine the health status based on a health related quality of life (HRQL) questionnaire (SF-20) and serum levels of interleukin 6 (IL-6) in subjects that are maca consumers. For this, a cross-sectional study was designed to be performed in 50 subjects from Junin (4,100 m): 27 subjects were maca consumers and 23 were non-consumers. The SF-20 survey is used to obtain a summary measure of health status. The stand up from a chair and sit down (SUCSD) test (to assess lower-extremity function), hemoglobin measurement, blood pressure, sexual hormone levels, serum IL-6 levels and the score of chronic mountain sickness (CMS) were evaluated. Testosterone/estradiol ratio (P <0.05), IL-6 (P < 0.05) and CMS score were lower, whereas the health status score was higher, in maca consumers when compared to non-consumers (P < 0.01). A greater proportion of maca consumers successfully completed the SUCSD test compared to non-consumers (P < 0.01), showing a significant association with lower values of serum IL-6 (P < 0.05). In conclusion, consumption of maca was associated with low serum IL-6 levels and in turn with better health status scores in the SF-20 survey and low chronic mountain sickness scores.

  12. Kaempferol glycosides and cardenolide glycosides, cytotoxic constituents from the seeds of Draba nemorosa (Brassicaceae).

    Science.gov (United States)

    Moon, Surk-Sik; Rahman, Md Aziz Abdur; Manir, Md Maniruzzaman; Jamal Ahamed, V S

    2010-08-01

    Bioassay-directed fractionation of a methanolic extract from the seeds of Draba nemorosa (Brassicaceae) led to isolation of a new flavonol glycoside, drabanemoroside (5, kaempferol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranose) along with four known flavonoid derivatives (1-4), four cardenolide glycosides (6-9). Kaempferol glycosides 2 and 5 showed strong cytotoxicity against human small lung cancer cell line A549 and melanoma SK-Mel-2 with an IC(50) of 0.5 microg/mL and 1.9 microg/mL, respectively. Cardenolide glycosides 6-9 showed potent cytotoxicity (A549) in the range of 0.01-0.032 microg/mL. Their structures were characterized based on spectroscopic data (2D NMR, HRTOFMS, IR, and UV) and comparison of literature values. The carbohydrate units were also confirmed by comparing the hydrolysate of 5 with authentic monosaccharides.

  13. [Chemical constituents of Lepidium meyenii].

    Science.gov (United States)

    Liang, Wen-juan; Xu, Hong-bo; Yang, Cai-yan; Geng, Chang-an; Zhang Xue-mei; Chen, Ji-jun

    2015-12-01

    To study the chemical constituents of Lepidium meyenii, the air-dried rhizome of L. meyenii was extracted with 70% EtOH. The extract was condensed to a small amount of volume and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isolated and purified by column chromatography, and identified based on spectral analyses (1H-NMR, 13C-NMR, HRESIMS). Eighteen compounds were isolated from L. meyenii, including 7 alkaloids and 4 fatty acids and 7 other compounds. They were characterized as (3-hydroxybenzyl) carbamic acid(1), phenylmethanamine(2), N-benzylformamide (3), N-benzylacetamide (4), pyridin-4-ylmethanamine(5), n-(4-methoxybenzyl) aniline(6), uracil(7), succininc acid(8), decanedioic acid(9), n-hexa- decanoic acid methyl ester(10), heptanoic acid(11), solerole(12), pyromucic acid methyl ester(13), 5-hydroxymethyl-2-furancar- boxadehyde(14), 5-(methoxymethyl)-1H-pyrrole-2-carbaldehyde(15), 1,7-dihydroxy-2,3, 4-trimethoxyxanthone (16), 1,7-di- hydroxy-3,4- dimethoxy-xanthone(17), (+)-pinoresinol(18). Meanwhile, compounds 1-18 were obtained from L. neyenii for the first time.

  14. Lepidium latifolium L.: een nieuw pekeladventief?

    NARCIS (Netherlands)

    Graaf, de J.M.

    1993-01-01

    Lepidium latifolium, originally a species of salt steppes, has been found at two localities near Leiden between pavement along road-sides. Its new habitat may have become suitable for it because of the frequent use of road-salt in winter.

  15. Synergistic antiosteoporotic effect of Lepidium Sativum and ...

    African Journals Online (AJOL)

    Alendronate belongs to a class of drugs called bisphosphonates. Bisphosphonates (BP) therapy is a vital option to reduce the risk of bone fracture in people who suffer from osteoporosis. Yet, bisphosphonate have displayed several side effects. Lepidium sativum (LS) seeds have been used in traditional folk medicine to ...

  16. Intra-individual variation and evolution of modular structure in Draba plants.

    Science.gov (United States)

    Grigorieva, Olga V; Cherdantsev, Vladimir G

    2014-09-01

    We studied the evolution of quantitative traits related to shoot system architecture in a large genus Draba (Brassicaceae) making emphasis on the dynamics of relationship between individual and intra-individual variation. The results suggest that selection leading to origin of different life forms arises mainly from a necessity of moderation of the non-adaptive contest between the egoistic plant modules, taking care of self-reproduction of their own. We separated two evolutionary trends, one leading to the formation of short-lived monocarpic, and the other to long-lived polycarpic forms from the short-lived polycarpic plants. The first trend concerns with transformation of the innovation shoots into the axillary inflorescences by shortening of their vegetative developmental phase, while the second one - with individuation of the plant modules owing to acquisition of the capacity of rooting and separating from the mother plant. In both trends, the turning points of the evolution are those of originating of the negative for individual plants interactions between the plant modules being indirect non-adaptive consequences of the previous adaptive evolution and initiating selection for rebuilding of the plant modular structure. The difference between selection operating on intra-individual and individual variations is that, in the first case, combining of the characters of different individuals is infeasible. This leaves no choice for the evolution but to change the developmental mechanisms. In the case considered in this work, this is a change in shoot architecture using the material afforded by the natural variability of developmental pathways of the plant modules. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Neuroprotective effects of Lepidium meyenii (Maca).

    Science.gov (United States)

    Pino-Figueroa, Alejandro; Nguyen, Diane; Maher, Timothy J

    2010-06-01

    The neuroprotective activity of the plant Lepidium meyenii (Maca) was studied in two experimental models: in vitro and in vivo. Crayfish neurons were pretreated with vehicle or the pentane extract from Maca, subjected to H(2)O(2), and their viability determined microscopically and chemically. A significant concentration-neuroprotective effect relationship was demonstrated. The pentane extract was then administered intravenously to rats prior to and following middle cerebral artery occlusion. While infarct volumes were decreased for the lower dose, higher doses increased infarct volumes compared to controls. These results suggest a potential application of Maca as a neuroprotectant.

  18. [Quality control of Maca (Lepidium meyenii)].

    Science.gov (United States)

    Shu, Ji-cheng; Cui, Hang-qing; Huang, Ying-zheng; Huang, Xiao-ying; Yang, Ming

    2015-12-01

    To control the quality of Maca, the quality standard was established in this study. According to the methods recorded in the Appendix of Chinese Pharmacopoeia (2010 Edition), the water, extract, total ash, acid insoluble substance, and heavy metals inspections in Lepidium meyenii were carried out. N-benzyl-9Z, 12Z-octadecadienamide in L. meyenii was identified by TLC, and it was determined by HPLC. The results showed that the N-benzyl-9Z, 12Z-octadecadienamide identification of TLC was a strong mark and specificity. In content determination experiment, the linearity of N-benzyl-9Z, 12Z-octadecadienamide was in the range of 0.01-2 microg (r = 0.9998), and the average recovery (n=9) was 99.27% (RSD 2.0%). The methods were simple, accurate, with good reproducibility. It is suitable for quality control L. meyenii.

  19. Chemical constituents from maca (lepidium meyenii)

    International Nuclear Information System (INIS)

    Zang, Z.; Li, M.J.; Ma, L.; Li, L.

    2016-01-01

    Two new natural products, tetrahydro-2-benzyl-1H-pyrrolo-(1,2-C) imidazole-1,3(2H) -dione (1) and (1S,4R,4aR,9aS)-4a-methyl-1,4,4a,9a- tetrahydro-1,4-methano-anthracene-9,10-dione (2), together with eleven known compounds (3-13) were isolated from the petroleum ether fraction of the 95% ethanol extract from the tubers of Lepidium meyenii. Among them, compounds 1 and 2 were new natural products, compounds 3, 4, 7-11, and 13 were isolated from L. meyenii for the first time. In addition, the spectroscopic data of compound 1 were firstly reported. Their structures were elucidated by 1D and 2D NMR spectroscopic analysis along with comparison with literature reports. (author)

  20. Effects of Nigella sativa and Lepidium sativum on Cyclosporine Pharmacokinetics

    Science.gov (United States)

    Al-Jenoobi, F. I.; Al-Suwayeh, S. A.; Muzaffar, Iqbal; Al-Kharfy, Khalid M.; Korashy, Hesham M.; Al-Mohizea, Abdullah M.; Raish, Mohd

    2013-01-01

    The present study was conducted to investigate the effects of Nigella sativa and Lepidium sativum on the pharmacokinetics of cyclosporine in rabbits. Two groups of animals were treated separately with Nigella sativa (200 mg/kg p.o.) or Lepidium sativum (150 mg/kg p.o.) for eight consecutive days. On the 8th day, cyclosporine (30 mg/kg p.o.) was administered to each group one hour after herbal treatment. Blood samples were withdrawn at different time intervals (0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12, and 24 hrs) from marginal ear vein. Cyclosporine was analyzed using UPLC/MS method. The coadministration of Nigella sativa significantly decreased the C max and AUC0−∞ of cyclosporine; the change was observed by 35.5% and 55.9%, respectively (P ≤ 0.05). Lepidium sativum did not produce any significant change in C max of cyclosporine, although its absorption was significantly delayed compared with control group. A remarkable change was observed in T max and AUC0−t of Lepidium sativum treated group. Our findings suggest that concurrent consumption of Nigella sativa and Lepidium sativum could alter the pharmacokinetics of cyclosporine at various levels. PMID:23957013

  1. A synopsis of the South American Lepidium (Brassicaceae)

    OpenAIRE

    Ihsan A. Al-Shehbaz

    2010-01-01

    Cincuenta especies nativas y 12 naturalizadas de Lepidium crecen en América del Sur, se presenta una clave para las 62 especies. Se describen e ilustran tres nuevas especies de Argentina (L. hickenii, L. pedersenii y L. santacruzensis) y dos para Perú (L. cuzcoensis y L. werffii), y se discuten sus relaciones con sus especies más afines. Se propone Lepidium crassius comb. nov., se designa lectotipo para 19 binomios (Coronopus didymus var. macrocarpus, C. didymus var. procumbens, L. abrotanifo...

  2. New alkamides from maca (Lepidium meyenii).

    Science.gov (United States)

    Zhao, Jianping; Muhammad, Ilias; Dunbar, D Chuck; Mustafa, Jamal; Khan, Ikhlas A

    2005-02-09

    Maca (Lepidium meyenii) has been used as a food in Peru for thousands of years. More recently a wide array of commercial maca products have gained popularity as dietary supplements, with claims of anabolic and aphrodisiac effects, although the biologically active principles are not fully known. In an earlier chemical investigation, two new alkamides and a novel fatty acid, as well as the N-hydroxypyridine derivative, macaridine, were isolated from L. meyenii. Further examination has led to the isolation of five additional new alkamides, namely, N-benzyl-9-oxo-12Z-octadecenamide (1), N-benzyl-9-oxo-12Z,15Z-octadecadienamide (2), N-benzyl-13-oxo-9E,11E-octadecadienamide (3), N-benzyl-15Z-tetracosenamide (4), and N-(m-methoxybenzyl)hexadecanamide (5). Their structures were established by spectrometric and spectroscopic methods including ESI-HRMS, EI-MS, (1)H, (13)C, and 2D NMR, as well as (1)H-(15)N 2D HMBC experiments. In addition, the identity of N-benzyl-15Z-tetracosenamide (4) was confirmed by synthesis. These compounds have been found from only L. meyenii and could be used as markers for authentication and standardization.

  3. The in vitro biological activity of Lepidium meyenii extracts

    Czech Academy of Sciences Publication Activity Database

    Valentová, K.; Buckiová, Daniela; Křen, Vladimír; Pěknicová, Jana; Ulrichová, J.; Šimánek, V.

    2006-01-01

    Roč. 22, - (2006), s. 91-99 ISSN 0742-2091 R&D Projects: GA MZd NJ7463 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50200510; CEZ:AV0Z50520514 Keywords : Lepidium meyenii * Maca * DPPH Subject RIV: FH - Neurology Impact factor: 1.400, year: 2006

  4. Polymorphic chloroplast microsatellite markers in the octoploid Lepidium meyenii (Brassicaceae) and cross-species amplification in Lepidium.

    Science.gov (United States)

    Hasan, Nabeeh A; Mummenhoff, Klaus; Quiros, Carlos F; Tay, C David; Bailey, C Donovan

    2010-10-01

    As a crop and medicinal plant, the octoploid Andean endemic Lepidium meyenii suffers from taxonomic uncertainty. Few molecular markers are available to genotype individuals or track gene flow in wild and cultivated material. • Using available sequence data, eight cpSSR primer pairs were developed for L. meyenii. Levels of polymorphism checked in 56 individual L. meyenii, including cultivated and wild material, revealed that the number of alleles per locus ranged from three to five, and intrapopulation allele frequencies ranged from 0.071 to 1.0. Polymerase-chain-reaction screens using our cpSSR primers in 27 other Lepidium species and three Coronopus species suggested a high degree of interspecific amplification. • These polymorphic cpSSR markers should prove useful in characterizing genetic variation among cultivated and wild L. meyenii. Additionally, interspecific amplifications suggest that these markers will be useful for the study of related taxa.

  5. Peruvian Maca: Two Scientific Names Lepidium Meyenii Walpers and Lepidium Peruvianum Chacon – Are They Phytochemically-Synonymous?

    Science.gov (United States)

    Meissner, Henry O.; Mscisz, Alina; Kedzia, Bogdan; Pisulewski, Pawel; Piatkowska, Ewa

    2015-01-01

    Using Liquid Chromatography-Mass Spectrometry (LCMS) , profiles of the two isotypes labelled under the same common name Maca deposited in the Medicinal Plant Herbarium, in Australia and Poland, but identified under two different scientific names Lepidium meyenii Walpers (L. meyenii) and Lepidium peruvianum Chacon (L. peruvianum) are presented. The two isotypes correspond to two holotypes of Peruvian medicinal herb known under the same common name “Maca”, as originally deposited in the Herbarium of San Marcos University in Lima, Peru dated back to 1843 and 1990 respectively. The results demonstrate distinct differences in taxonomy, visual appearance, phytochemical profiles and DNA sequences of the two researched Maca isotypes, suggesting that the two Maca specimens are dissimilar and formal use of the term “synonymous” to L. meyenii and L. peruvianum may be misleading. On the basis of presented results the scientific name L. meyenii, used since 1843 up-today for cultivated Peruvian Maca by numerous reference sources worldwide, including Regulatory Bodies in the USA, EU, Australia and most lately in China, appears to be used in error and should be formally revised. It is concluded, that the isotype of cultivated Peruvian Maca labelled under its scientific name Lepidium peruvianum Chacon, provides all the characteristics peculiar to this historically-documented herb grown in Andean highlands, which may be linked to its traditional use and accepted functionality, confirmed in recent clinical study to be relevant to its present day use for expected dietary, therapeutic and health benefits.

  6. Molecular genetic diversity study of Lepidium sativum population ...

    African Journals Online (AJOL)

    Vostro 2520

    Generally, Tigray and Amhara regions showed moderate to high diversity in ISSR analysis. ... other crops. The main purpose of its cultivation in. Ethiopia is to use it as a medicinal plant. It is used for human abdominal ache and diarrhea. Moreover, L. ... of 10 primers were obtained from the Genetic Research Laboratory.

  7. A synopsis of the South American Lepidium (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Ihsan A. Al-Shehbaz

    2010-01-01

    Full Text Available Cincuenta especies nativas y 12 naturalizadas de Lepidium crecen en América del Sur, se presenta una clave para las 62 especies. Se describen e ilustran tres nuevas especies de Argentina (L. hickenii, L. pedersenii y L. santacruzensis y dos para Perú (L. cuzcoensis y L. werffii, y se discuten sus relaciones con sus especies más afines. Se propone Lepidium crassius comb. nov., se designa lectotipo para 19 binomios (Coronopus didymus var. macrocarpus, C. didymus var. procumbens, L. abrotanifolium var. steinmannii, L. affine, L. argentinum, L. auriculatum, L. bonariense var. pseudovirginicum, L. calycinum var. integrifolium, L. costaricense, L. cumingianum var. orbiculatum, L. cumingianum subsp. berteroanum, L. depressum, L. myrianthum, L. neglectum, L. parodii, L. pubescens var. fallax, L. subvaginatum, L. virginicum subsp. centrali-americanum, Thlaspi campestre, y se reducen a sinónimos otros 17 nombres (Coronopus leptocarpus, C. leptocarpus var. microcarpus, L. boelckii, L. bonariense var. gayi, L. bonariense var. pseudovirginicum, L. brevicaule, L. calycinum, L. danielsii, L. demissum, L. kalenbornii, L. morrisonii, L. peruvianum, L. philippianum var. boliviense, L. raimondii, L. scabrifructum, L. spicatum var. caylx-persistente, L. subvaginatum. L. depressum y L. rahmeri son nuevos registros para la Argentina.

  8. Presence of oligosaccharides in seed-coat mucilage of Lepidium sativum : role in allelopathy

    OpenAIRE

    Iqbal, Amjad

    2010-01-01

    Lepidimoide is a naturally occurring disaccharide reported to be an oligosaccharin, i.e. to exhibit ‘hormone-like’ biological activity. It was found in cress (Lepidium sativum) root exudates and exerts apparently allelopathic effects on neighbouring Amaranthus seedlings. In the present study the effect of cress root exudates on hypocotyl and root length of Amaranthus caudatus and Lactuca sativa was studied. The seedlings of both species grown with Lepidium sativum seedlings had...

  9. Optimization of the new formulation of ice cream with native Iranian seed gums (Lepidium perfoliatum and Lepidium sativum) using response surface methodology (RSM).

    Science.gov (United States)

    Azari-Anpar, M; Soltani Tehrani, N; Aghajani, N; Khomeiri, M

    2017-01-01

    In this study, effect of Qodume shahri ( Lepidium perfoliatum ) and cress ( Lepidium sativum ) on rheological properties of ice cream were investigated. The gums were added to the ice cream formulation and different quality attributes including pH, acidity, melting characteristics, viscosity, overrun, texture analysis and sensory evaluation were determined. Results showed that ice cream formulations containing both the gums had improved overrun, melting rate, first dripping time, viscosity, hardness and adhesiveness. The gum concentrations beyond 0.2% level led to a negative effect on gumminess and chewiness of ice cream. Both the gums addition to improved quality attributes and textural properties of ice cream.

  10. Antiamoebic activity of benzyl glucosinolate from Lepidium virginicum.

    Science.gov (United States)

    Calzada, Fernando; Barbosa, Elizabeth; Cedillo-Rivera, Roberto

    2003-06-01

    In a continuation of our search for potential antiprotozoal agents from plants, we found that a crude extract from the roots of Lepidium virginicum exhibited antiprotozoal activity against Entamoeba histolytica trophozoites (IC(50) of 100.1 micro g/mL). Bioassay-guided fractionation resulted in the isolation of one known glucosinolate responsible for such activity. This compound was identified as benzyl glucosinolate. It showed in vitro activity against Entamoeba histolytica strain HM1-IMSS (IC(50) of 20.4 micro g/mL). The results support the anecdotal reports for the traditional use of L. virginicum roots in the control of diarrhoea and dysentery in the highlands of Chiapas, Mexico. Copyright 2003 John Wiley & Sons, Ltd.

  11. Effect of SO/sub 2/ on sexual reproduction in Lepidium virginicum L. originating from regions with different SO/sub 2/ concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Murdy, W.H.

    1979-09-01

    Tolerance of SO/sub 2/ with respect to sexual reproduction is reported for populations of Lepidium virginicum from the Copper Basin of Tennessee, a region subjected to SO/sub 2/ pollution for the past 75 yr. The offspring of plants from inside and outside the Copper Basin were fumigated with 2130 ..mu..g/m/sup 2/ SO/sub 2/ for 9 h at high relative humidity in replicated experiments. As a result of SO/sub 2/ stress, plants from outside the Copper Basin were less fertile than plants from inside the Copper Basin.

  12. Structural Characterization and Immunomodulatory Activity of a Novel Polysaccharide from Lepidium meyenii.

    Science.gov (United States)

    Zhang, Mengmeng; Wang, Guang; Lai, Furao; Wu, Hui

    2016-03-09

    A novel polysaccharide named as MC-1 was isolated from the roots of Lepidium meyenii using a water extraction method. Structural characterization revealed that MC-1 had an average molecular weight of 11.3 kDa and consisted of arabinose (26.21%), mannose (11.81%), glucose (53.66%), and galactose (8.32%). The main linkage types of MC-1 were proven to be (1 → 5)-α-L-Ara, (1 → 3)-α-L-Man, (1 → 2,6)-α-L-Man, (1 → )-α-D-Glc, (1 → 4)-α-D-Glc, (1 → 6)-α-D-Glc and (1 → 6)-β-D-Gal by methylation analysis, periodate oxidation-Smith degradation and NMR analysis. The immunostimulating assay indicated that MC-1 could significantly enhance the pinocytic and phagocytic capacity and promote the NO, TNF-α, and IL-6 secretion of RAW 264.7 cells, involving toll-like receptor 2, complement receptor 3, and mannose receptor mainly. These results suggested the potential utilization of MC-1 as an attractive functional food supplement candidate for hypoimmunity population.

  13. [Study on Chemical Constituents of Fat-soluble Extraction from Lepidium meyenii].

    Science.gov (United States)

    Fan, Cai-hong; Ge, Fa-huan

    2015-02-01

    To study the chemical constituents of the fat-soluble extraction from Lepidium meyenii root. Different extraction methods were studied, including supercritical carbon dioxide extraction, circumfluence extraction and steam distillation. Chemical constituents of the fat-soluble extraction from Lepidium meyenii were analyzed by GC/MS. The number of compounds isolated by the above four methods were 38, 31, 14, 21 (specific gravity less than 1 in steam distillation) , and 25 (specific gravity greater than 1 in steam distillation), accounting for 85.79%, 81.18%, 62.08%, 98.36% (specific gravity less than 1 in steam distillation) and 81.54% (specific gravity greater than 1 in steam distillation) of each total peak area, respectively. This study lays a certain foundation for further study and development of functional factors in Lepidium meyenii root.

  14. Semi-quantitative analysis of transcript accumulation in response to drought stress by Lepidium latifolium seedlings.

    Science.gov (United States)

    Gupta, Sanjay Mohan; Singh, Sadhana; Pandey, Pankaj; Grover, Atul; Ahmed, Zakwan

    2013-09-01

    Cross-amplification of five Arabidopsis abiotic stress-responsive genes (AtPAP, ZFAN, Vn, LC4 and SNS) in Lepidium has been documented in plants raised out of seeds pre-treated with potassium nitrate (KNO 3) for assessment of enhanced drought stress tolerance. cDNA was synthesized from Lepidium plants pre-treated with KNO 3 (0.1% and 0.3%) and exposed to drought conditions (5% and 15% PEG) at seedling stage for 30 d. Transcript accumulation of all the five genes were found suppressed in set of seedlings, which were pre-treated with 0.1% KNO 3 and were exposed to 15% PEG for 30 d. The present study establishes that different pre-treatments may further enhance the survivability of Lepidium plants under conditions of drought stress to different degrees.

  15. [Maca (Lepidium meyenii Walp), a review of its biological properties].

    Science.gov (United States)

    Gonzales, Gustavo F; Villaorduña, Leonidas; Gasco, Manuel; Rubio, Julio; Gonzales, Carla

    2014-01-01

    Maca (Lepidium meyenii) is a plant that grows above 4000 altitude meters in Peru's Central Andes; it has different varieties according to the color of the hypocotyl. This review summarizes the results of studies about the effects of maca on sexual function, spermatogenesis, female reproductive function, memory, depression and anxiety, and energy as well as effects on benign prostatic hyperplasia, osteoporosis and metabolic syndrome. Its anti-aging effect is also discussed as well as safety in consumption. Differences have been shown between the effects of the black, yellow and red maca varieties. Black maca shows the best results on spermatogenesis, memory and fatigue, while red maca is the variety that reverses the benign prostatic hyperplasia and experimentally induced osteoporosis. In addition, maca reduces the glucose levels, and its consumption is related to the lowering of blood pressure and an improved health score. Experimental studies have proven that short and long term consumption don't show in vivo and in vitro toxicity. Although experimental studies have shown that maca has diverse beneficial effects, more clinical studies are needed to confirm these results.

  16. The in vitro biological activity of Lepidium meyenii extracts.

    Science.gov (United States)

    Valentová, K; Buckiová, D; Kren, V; Peknicová, J; Ulrichová, J; Simánek, V

    2006-03-01

    The biological activity of methanolic and aqueous extracts from dehydrated hypocotyls of Lepidium meyenii (Brassicaceae, vernacular name "maca"), was studied on rat hepatocytes and human breast cancer MCF-7 cells. The extracts did not exhibit cytotoxicity in hepatocyte primary cultures up to 10 mg/ml as measured by the MTT viability test, and lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) leakage. Moreover, after 72 h, extracts inhibited LDH and AST leakage from the hepatocytes. When hepatocytes were intoxicated by t-butyl hydroperoxide, neither extract prevented oxidative damage. Both extracts showed weak antioxidant activity in the DPPH radical scavenging test with IC(50) values of 3.46 +/- 0.16 and 0.71 +/- 0.10 mg/ml, for aqueous and methanolic extracts, respectively. Thus, the observed effect on spontaneous enzyme leakage is probably mediated through mechanisms other than antioxidant activity. Both methanolic and aqueous extracts have shown estrogenic activity comparable with that of silymarin in MCF-7 cell line. Maca estrogenicity was exhibited in the range from 100 to 200 mug of extract per ml. The findings in the present study show that maca does not display in vitro hepatotoxicity. In contrast, a slight cytoprotective effect, probably not mediated by antioxidant capacity, was noted. Maca extracts exhibited estrogenic activity comparably to the effect of silymarin in MCF-7 cells.

  17. Composition and Physical Properties of Cress (Lepidium sativum L.) and Field Pennycress (Thlaspi arvense L.) Oils

    Science.gov (United States)

    The fatty acid profile and tocopherol, and phytosterol contents of crude cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) oils are reported, along with yields from the corresponding seeds. The physical properties of these oils were also determined, which included oxidative stab...

  18. Crystallization of water-soluble chlorophyll-proteins from Lepidium virginicum.

    Science.gov (United States)

    Murata, T; Itoh, R; Yakushiji, E

    1980-11-05

    Water-soluble chlorophyll-proteins were prepared from leaves of Lepidium virginicum, by means of ammonium sulfate fractionation followed by column chromatography on DEAE-cellulose and Sephacryl S-200. After intensive purification the chlorophyll-proteins were crystallized by dialysis against an ammonium sulfate solution.

  19. Use of Gelatinized Maca (Lepidium Peruvianum) in Early Postmenopausal Women

    Science.gov (United States)

    Meissner, H. O.; Kapczynski, W.; Mscisz, A.; Lutomski, J.

    2005-01-01

    Objective: This double-blind, placebo-corrected clinical pilot study was aimed at assessing the use of hypocotyls of cruciferous Andean plant Maca (Lepidium peruvianum Chacon), in alleviating symptoms of menopausal discomfort experienced by women in early post menopause as measured by profiles of serum hormones: Luteinizing Hormone (LH), Follicle-stimulating Hormone (FSH), Estrogen (E2) and Progesterone (PG) and as assessed by Greene’s Menopausal Index. Design: Study was conducted on 20 Caucasian healthy early-postmenopausal women volunteers during the three months period (Trial I) and on eight women during nine months period (Trial II). Hormone levels were determined in blood with a simultaneous assessment of menopausal index at the start of study, after one month use of placebo, and after two and eight months administration of 2g gelatinized Maca root powder (Maca-GO) in the form of two 500mg hard gel capsules, twice daily. Results: In comparison to placebo, after both, two and eight months administration of Maca-GO capsules to EPMW, level of FSH significantly (PMaca-GO treatment only. There was a significant (PMaca-GO when used in EPMW, depending on the length of use, was acting as a toner of hormonal processes as reflected by decrease in FSH and increased LH secretion, which stimulated production of both ovarian hormones, E2 and PG and resulted in a substantial reduction of menopausal discomfort felt by women participating in the study, with a distinctive placebo effect, thus, fully justifying further, more complex study on effectiveness of Maca-GO as a reliable alternative to HRT program. PMID:23674952

  20. Actividad leishmanicida de los extractos metanólicos de cuatro ecotipos de Lepidium peruvianum, Chacón (Brassicaceae)

    OpenAIRE

    Alzamora, Libertad; Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Biológicas, Instituto de Investigaciones de Ciencias Biológicas Antonio Raimondi, Laboratorio de Inmunología; Solís, Hilda; Universidad Nacional Mayor de San Marcos. Facultad de Medicina Humana. Instituto de Medicina Tropical «Daniel Alcides Carrión»; Rojas, Marisol; Universidad Nacional Mayor de San Marcos. Facultad de Medicina Humana. Instituto de Medicina Tropical «Daniel Alcides Carrión»; Calderón, Marisela; Universidad Nacional Mayor de San Marcos. Facultad de Medicina Humana. Instituto de Medicina Tropical «Daniel Alcides Carrión»; Fajardo, Narda; Universidad Nacional Mayor de San Marcos. Facultad de Medicina Humana. Instituto de Medicina Tropical «Daniel Alcides Carrión»; Quispe, Jenny; Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Biológicas, Instituto de Investigaciones de Ciencias Biológicas Antonio Raimondi, Laboratorio de Inmunología; Alvarez, Evelyn; Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Biológicas, Instituto de Investigaciones de Ciencias Biológicas Antonio Raimondi, Laboratorio de Inmunología; Colona, Erasmo; Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Biológicas, Instituto de Investigaciones de Ciencias Biológicas Antonio Raimondi, Laboratorio de Inmunología; Torres, Dina; Universidad Nacional Mayor de San Marcos, Facultad de Ciencias Biológicas, Instituto de Investigaciones de Ciencias Biológicas Antonio Raimondi, Laboratorio de Inmunología

    2013-01-01

    The classic treatment of the cutaneous leishmaniosis consists on the injection of 15-20 ampoule of Glucantine what causes serious secondary effects. This fact justifies the search of new medications what motivated the present investigation. The objective was to evaluate the leishmanicidal activity of the methanolic extracts (ME) of the white, red, purple and black ecotypes of Lepidium peruvianum Chacón (at present Lepidium meyenii Walp.) about the growth of Leishmania braziliensis peruviana i...

  1. Extraction, purification and antioxidant activities of the polysaccharides from maca (Lepidium meyenii).

    Science.gov (United States)

    Zha, Shenghua; Zhao, Qingsheng; Chen, Jinjin; Wang, Liwei; Zhang, Guifeng; Zhang, Hong; Zhao, Bing

    2014-10-13

    Water-soluble polysaccharides were separated from maca (Lepidium meyenii) aqueous extract (MAE). The crude polysaccharides were deproteinized by Sevag method. During the preparation process of maca polysaccharides, amylase and glucoamylase effectively removed starch in maca polysaccharides. Four Lepidium meyenii polysaccharides (LMPs) were obtained by changing the concentration of ethanol in the process of polysaccharide precipitation. All of the LMPs were composed of rhamnose, arabinose, glucose and galactose. Antioxidant activity tests revealed that LMP-60 showed good capability of scavenging hydroxyl free radical and superoxide radical at 2.0mg/mL, the scavenging rate was 52.9% and 85.8%, respectively. Therefore, the results showed that maca polysaccharides had a high antioxidant activity and could be explored as the source of bioactive compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Value of reduced / oxidized glutathione (GSH / GSSG) in diabetic rats treated with maca (Lepidium meyenii Walp)

    OpenAIRE

    Cisneros, Ruth; Oré, Raque; Arnao, Inés; Suárez, Silvia

    2013-01-01

    Background: Diabetes mellitus and its complications are public health problems. Hyperglycemia triggers harmful biochemical effects to the body, such as oxidative stress and inflammatory process. The use of medicinal plants with high antioxidant capacity as Lepidium meyenii Walp (maca) is an alternative in treatment of this disease. Objective: To determine whether ingestion of maca flour improves the relation reduced/oxidized glutathione (GSH/GSSG) in diabetic rats. Design: Experimental. Setti...

  3. Peruvian Maca (Lepidium peruvianum): (I) Phytochemical and Genetic Differences in Three Maca Phenotypes

    OpenAIRE

    Meissner, Henry O.; Mscisz, Alina; Mrozikiewicz, Mieczyslaw; Baraniak, Marek; Mielcarek, Sebastian; Kedzia, Bogdan; Piatkowska, Ewa; Jólkowska, Justyna; Pisulewski, Pawel

    2015-01-01

    Glucosinolates were previously reported as physiologically-important constituents present in Peruvian Maca (Lepidium peruvianum Chacon) and linked to various therapeutic functions of differently-colored Peruvian Maca hypocotyls. In two separate Trials, three colours of Maca hypocotyls “Black”, “Red” and “Yellow” (termed “Maca phenotypes”), were selected from mixed crops of Peruvian Maca for laboratory studies as fresh and after being dried. Individual Maca phenotypes were cultivated in the hi...

  4. Alien Species of Lepidium in the Flora of Romania: Invasion History and Habitat Preference

    OpenAIRE

    Culiţă SÎRBU; Adrian OPREA; Cristian Valeriu PATRICHE; Costel SAMUIL; Vasile VÎNTU

    2014-01-01

    The history of spread and habitat preferences during invasion of four alien species of Lepidium in Romania, namely L. densiflorum, L. oblongum, L. sativum, and L. virginicum are presented in this paper. The floristic records of these species, collected between 1816 and 2013, were used in the study. L. sativum was sporadically mentioned by earlier botanic references, as a casual alien plant in ruderal places. L. oblongum was reported from a single locality, but it may be considered a potential...

  5. Lepidium sativum Linn.: a current addition to the family of mucilage and its applications.

    Science.gov (United States)

    Prajapati, Vipul D; Maheriya, Pankaj M; Jani, Girish K; Patil, Prasant D; Patel, Bhumit N

    2014-04-01

    Mucilage from the last decades has been found to be very attractive, interesting and useful in development of desired pharmaceutical dosage forms. Various applications of plant based mucilage have a wide potentiality in drug formulations. Lepidium sativum Linn. (family: Brassicaceae) is one of the mucilage containing fast growing, edible annual herb. Its various parts (roots, leaves and seeds) have been used to treat various human ailments. It mainly contains alkaloids, saponins, anthracene glycosides, carbohydrates, proteins, amino acids, flavanoids, and sterols as chief phytochemical constituents. Its seed extracts have been screened for various biological activities like hypotensive, anti-microbial, bronchodilator, hypoglycemic and allelopathic, whereas its seed coat mucilage has been isolated using different methods to make it effective excipient of desired functionality as a part of pharmaceutical applications. Through keen references of reported work on Lepidium sativum Linn., in this review, we have focused on its seed coat mucilage isolation methods, chemical constituents, pharmacological profile and versatile application of Lepidium sativum Linn. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A bicontinental origin of polyploid Australian/New Zealand Lepidium species (Brassicaceae)? Evidence from genomic in situ hybridization.

    Science.gov (United States)

    Dierschke, Tom; Mandáková, Terezie; Lysak, Martin A; Mummenhoff, Klaus

    2009-09-01

    Incongruence between chloroplast and nuclear DNA phylogenies, and single additive nucleotide positions in internal transcribed spacer (ITS) sequences of polyploid Australian/New Zealand (NZ) Lepidium species have been used to suggest a bicontinental hybrid origin. This pattern was explained by two trans-oceanic dispersals of Lepidium species from California and Africa and subsequent hybridization followed by homogenization of the ribosomal DNA sequence either to the Californian (C-clade) or to the African ITS-type (A-clade) in two different ITS-lineages of Australian/NZ Lepidium polyploids. Genomic in situ hybridization (GISH) was used to unravel the genomic origin of polyploid Australian/NZ Lepidium species. Fluorescence in situ hybridization (FISH) with ribosomal DNA (rDNA) probes was applied to test the purported ITS evolution, and to facilitate chromosome counting in high-numbered polyploids. In Australian/NZ A-clade Lepidium polyploids, GISH identified African and Australian/NZ C-clade species as putative ancestral genomes. Neither the African nor the Californian genome were detected in Australian/NZ C-clade species and the Californian genome was not detected in Australian/NZ A-clade species. Five of the eight polyploid species (from 7x to 11x) displayed a diploid-like set of rDNA loci. Even the undecaploid species Lepidium muelleriferdinandi (2n = 11x = 88) showed only one pair of each rDNA repeat. In A-clade allopolyploids, in situ rDNA localization combined with GISH corroborated the presence of the African ITS-type. The nuclear genomes of African and Australian/NZ C-clade species were detected by GISH in allopolyploid Australian/NZ Lepidium species of the A-clade, supporting their hybrid origin. The presumed hybrid origin of Australian/NZ C-clade taxa could not be confirmed. Hence, it is assumed that Californian ancestral taxa experienced rapid radiation in Australia/NZ into extant C-clade polyploid taxa followed by hybridization with African species. As a

  7. Utilización de Lepidium peruvianum maca, como medio de cultivo para el crecimiento de Trypanosoma cruzi

    OpenAIRE

    Saldaña C, Charles; Córdova P, Ofelia; Instituto de Investigación en Microbiología y Parasitología Tropical. Universidad Nacional de Trujillo. La Libertad, Perú.; Vargas V, Franklin; Instituto de Investigación en Microbiología y Parasitología Tropical. Universidad Nacional de Trujillo. La Libertad, Perú.

    2006-01-01

    Por sus características nutritivas de alto valor, se ensayó la posible utilidad del Lepidium peruvianum maca, como un medio para cultivar Trypanosoma cruzi. Bajo condiciones experimentales se procedió a incubar epimastigotes de T. cruzi en cuatro medios de cultivo bifásicos diferentes, a base de Lepidium peruvianum maca, los cuales fueron comparados con el medio de cultivo BHI como control. La incorporación de maca como medio de cultivo permitió el crecimiento de Trypanosoma cruzi; se determi...

  8. Optimized methodology for the simultaneous extraction of glucosinolates, phenolic compounds and antioxidant activity from maca (Lepidium meyenii)

    NARCIS (Netherlands)

    Campos, D.; Chirinos, R.; Barreto, O.; Noratto, G.; Pedreschi Plasencia, R.P.

    2013-01-01

    Maca is a highly appreciated Andean crop with multiple attributed health claims due to its assortment of bioactive compounds. The extraction parameters of glucosinolates (GLs), total phenolic compounds (TPC) and antioxidant capacity (AC) of maca (Lepidium meyenii) hypocotyls were optimized using

  9. Extraction of Lepidium apetalum Seed Oil Using Supercritical Carbon Dioxide and Anti-Oxidant Activity of the Extracted Oil

    Directory of Open Access Journals (Sweden)

    Xuchong Tang

    2011-12-01

    Full Text Available The supercritical fluid extraction (SFE of Lepidium apetalum seed oil and its anti-oxidant activity were studied. The SFE process was optimized using response surface methodology (RSM with a central composite design (CCD. Independent variables, namely operating pressure, temperature, time and flow rate were evaluated. The maximum extraction of Lepidium apetalum seed oil by SFE-CO2 (about 36.3% was obtained when SFE-CO2 extraction was carried out under the optimal conditions of 30.0 MPa of pressure, 70 °C of temperature, 120 min of extraction time and 25.95 L/h of flow rate. GC-MS analysis showed the presence of four fatty acids in Lepidium apetalum seed oil, with a high content (91.0% of unsaturated fatty acid. The anti-oxidant activity of the oil was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical-scavenging assay and 2,2′-azino- bis(3-ethylbenzthiazoline-6-sulphonic acid diammonium salt (ABTS test. Lepidium apetalum seed oil possessed a notable concentration-dependent antioxidant activity, with IC50 values of 1.00 and 3.75 mg/mL, respectively.

  10. Effect of different levels of Lepidium sativum L. on growth performance, carcass characteristics, hematology and serum biochemical parameters of broilers.

    Science.gov (United States)

    Shawle, Kassa; Urge, Mengistu; Animut, Getachew

    2016-01-01

    Frequent use of antibiotics to stimulate growth and health of animals leads to the development of antibiotic-resistant populations of microorganisms. In this context, alternatives like herbs and spices to antibiotics are of importance, as they are natural products. Therefore, the present experiment was designed to evaluate the performance, carcass traits, hematology and serum biochemical parameters of broilers fed ration containing varying levels of Lepidium satvium (Garden cress) seed powder as feed additive up to the age of 42 days. A total of 204 Cobb-500 day-old broiler chicks were randomly distributed into four treatments with three replicates of 17 chicks each. Garden cress (GC) was included in the ration at 0 (0GC), 0.75 (0.75GC), 1.50 (1.5GC) and 2.25 % (2.25GC) in each treatments. Growth performance, carcass characteristics, heamatology, serum biochemical and economic efficiency parameters were observed. The crude protein, ether extract and crude fiber content of GC were 22.4, 25.7 and 10.5 %, respectively. Daily dry matter intake and average daily gain during the entire experimental period were affected (p  0.05). Sex differences were significant for eviscerated, carcass and kidney percentages with greater values for females than males. All hematological parameters were within the normal range. However, inclusion of GC improved (p health of broilers. Based on the production parameters used in the study, GC can be included as feed additive at a level of 0.75 % in the total ration for better and positive results on biological performance and health status of broilers.

  11. Synergistic effect of the hydroalcoholic extract from Lepidium meyenii (Brassicaceae) and Fagara tessmannii (Rutaceae) on male sexual organs and hormone level in rats.

    Science.gov (United States)

    Lembè, Dieudonné Massoma; Gasco, Manuel; Gonzales, G F

    2014-01-01

    Lepidium meyenii is a plant, which has been used in folk medicine to treat infertility and to increase sexual desire. However, few reports have investigated the administration of this plant with other plants having the same properties. The present investigation was designed to evaluate whether the combination of Lepidium meyenii and Fagara tessmannii can improve spermatogenesis and testosterone level in rats. Twenty male rats were treated daily for 2 weeks with the hydroalcoholic extract of Fagara tessmannii and Lepidium meyenii (Fag + MN) as follow: (vehicle), (0.01 g + 0.5 mg), (0.1 g + 5 mg) and (1 g+ 50 mg)/kg BW. At doses Fag 0.01 g/MN 0.5 mg and Fag 0.1 g/MN 5 mg, the weight of seminal vesicle, prostate, and testis significantly decreased (P Lepidium meyenii (Black Maca) with Fagara tessmannii can improve male reproductive organs activities.

  12. Physicochemical and functional properties of dietary fiber from maca (Lepidium meyenii Walp.) liquor residue.

    Science.gov (United States)

    Chen, Jinjin; Zhao, Qingsheng; Wang, Liwei; Zha, Shenghua; Zhang, Lijun; Zhao, Bing

    2015-11-05

    Using maca (Lepidium meyenii) liquor residue as the raw material, dietary fiber (DF) was prepared by chemical (MCDF) and enzymatic (MEDF) methods, respectively, of which the physicochemical and functional properties were comparatively studied. High contents of DF were found in MCDF (55.63%) and MEDF (81.10%). Both fibers showed good functional properties, including swelling capacity, water holding capacity, oil holding capacity, glucose adsorption capacity and glucose retardation index. MEDF showed better functional properties, which could be attributed to its higher content of DF, more irregular surface and more abundant monosaccharide composition. The results herein suggest that maca DF prepared by enzymatic method from liquor residue is a good functional ingredient in food products. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. [Assesing the effect of Lepidium meyenii "Maca" on the gastric mucosa in patients with functional dyspepsia].

    Science.gov (United States)

    Benites Goñi, Harold Eduardo; Cok García, Jaime; Bussalleu Cavero, Alejandra; Bustamente Robles, Katherine Yelenia; Zegarra Chang, Arturo; Bravo, Eduar; Bussalleu Rivera, Alejandro

    2014-01-01

    The present study was designed to determine the histological effect of Lepidium meyenii "Maca" on the gastric mucosa in patients with functional dyspepsia. This study consists of a clinical case series, in which the effect of Maca on the gastric histopathology of 29 Peruvian patients diagnosed with functional dyspepsia was examined. The presence of H. pylori, as well as the degree and depth of the gastric mucosa inflammation was evaluated from biopsies obtained before and after the treatment based solely of Maca 3 grams per day for four weeks. Average values of the degree and depth of mucosal inflammation before and after the treatment were compared showing no statistical difference among the samples. Sixteen patients were infected with H. pylori, and they remained infected after the treatment with Maca. A four week long treatment with Maca does not produce significant changes on gastric mucosa of patients with functional dyspepsia, neither on H. pylori eradication.

  14. Effect of ethanol extract of Lepidium meyenii Walp. on osteoporosis in ovariectomized rat.

    Science.gov (United States)

    Zhang, Yongzhong; Yu, Longjiang; Ao, Mingzhang; Jin, Wenwen

    2006-04-21

    Maca (Lepidium meyenii Walp.) is a cruciferous plant from the Andes of Peru. The root of Maca is traditionally employed for its supposed properties in aphrodisiacs and improving fertility, it also has been widely used to help alleviate the symptoms of menopause. The purpose of this study was to evaluate the effect of ethanol extract of Maca on postmenopausal osteoporosis in ovariectomized rats. Female Sprague-Dawley rats were divided into four groups: Sham-operated and ovariectomized groups were fed with equivolume of distilled water, and the remaining ovariectomized groups were orally administrated with ethanol extract of Maca at 0.096 and 0.24 g/kg for 28 weeks. The findings derived from the basis of bone mineral density, biomechanical, biochemical and histopathological parameters indicated that higher dose of ethanol extract of Maca was effective in the prevention of estrogen deficient bone loss.

  15. Analysis of macamides in samples of Maca (Lepidium meyenii) by HPLC-UV-MS/MS.

    Science.gov (United States)

    McCollom, Megan M; Villinski, Jacquelyn R; McPhail, Kerry L; Craker, Lyle E; Gafner, Stefan

    2005-01-01

    The macamides are a distinct class of secondary metabolites that have so far been found only in Lepidium meyenii Walp. (Maca). Using HPLC-UV-MS/MS, the main macamides have been identified as n-benzylhexadecanamide, n-benzyl-(9Z)-octadecenamide, n-benzyl-(9Z, 12Z)-octadecadienamide, n-benzyl-(9Z, 12Z, 15Z)-octadecatrienamide and n-benzyloctadecanamide. The identities of n-benzyl-(9Z)-octadecenamide and n-benzyl-(9Z, 12Z)-octadecadienamide were confirmed by comparison of chromatographic and spectral properties with synthetic analogues. Total macamides have been quantified by HPLC-UV in plant material from different vendors using n-benzylhexadecanamide as an external standard. The amount of macamides in the dried plant material ranged from 0.0016 to 0.0123%.

  16. 2D spectroscopy study of water-soluble chlorophyll-binding protein from Lepidium virginicum.

    Science.gov (United States)

    Alster, Jan; Lokstein, Heiko; Dostál, Jakub; Uchida, Akira; Zigmantas, Donatas

    2014-04-03

    Water-soluble chlorophyll-binding proteins (WSCPs) are interesting model systems for the study of pigment-pigment and pigment-protein interactions. While class IIa WSCP has been extensively studied by spectroscopic and theoretical methods, a comprehensive spectroscopic study of class IIb WSCP was lacking so far despite the fact that its structure was determined by X-ray crystallography. In this paper, results of two-dimensional electronic spectroscopy applied to the class IIb WSCP from Lepidium virginicum are presented. Global analysis of 2D data allowed determination of energy levels and excitation energy transfer pathways in the system. Some additional pathways, not present in class IIa WSCP, were observed. The data were interpreted in terms of a model comprising two interacting chlorophyll dimers. In addition, oscillatory signals were observed and identified as coherent beatings of vibrational origin.

  17. La Maca (Lepidium peruvianum Chacón sp. nov. y su Habitat

    Directory of Open Access Journals (Sweden)

    Gloria Chacon

    2014-06-01

    Full Text Available Este estudio presenta la descripción taxonómica de un ejemplar tipo de la MACA obtenido el 9 de septiembre de 1989 cerca de Huarancaca, ciudad de Cerro de Pasco, del Departamento de Pasco, como Lepidium peruvianum Chacon sp. nov., especie nueva para el género Lepidium (CRUCIFERA, las características que la distinguen de las especies afines especialmente de Lepidium meyenii Walp. y de Lepidium gelidium Wedd. están especificadas en este estudio. Igualmente presenta el estudio fitoquímico de la MACA realizado en 1960-1962, su hábitat y aclimatación a niveles de la costa. Esta especie cuyo nombre es MACA es oriunda de los Andes Centrales del Perú y se la conoce tanto por su valor alimenticio como farmacológico desde antes de la época del incanato. Crece en los Departamentos de Pasco y Junín en altitudes de 4100 y 4300 m sobre el nivel del mar. El clima en esta región es frío y seco durante el año caracterizándose el verano (enero, febrero y marzo como lluvioso con un promedio de 250,8 mm y con una temperatura ambiental promedio de 4.8 °C. En invierno (junio, julio y agosto las lluvias son escasas llegando a 34.4 mm y el promedio de la temperatura ambiental es alrededor de 3.5 °C. Los análisis químicos de la raíz realizados en 1960 y 1961 han demostrado la presencia de glúcidos y cuatro tipos de alcaloides, presentadas en cromatografía de papel Whatman. Estos alcaloides que he denominado "Extracto alcaloideo/marzo 1961", son los principios activos que intervienen en la frecuencia de procreación y dela clara y marcada estimulación de la maduración de los folículos de Graaf realizados en experimentos con ratas y en los machos, un aumento en la cantidad de espermatozoides en los tubos seminíferos y aumento de mitosis y espermatogonia. Estos ensayos los he realizado en el Instituto de Patología de la Facultad de Medicina Humana [de la UNMSM] durante los años 1961 y 1962. Las observaciones histológicas e histoqu

  18. Evaluation of nutritional and antioxidant status of Lepidium latifolium Linn.: a novel phytofood from Ladakh.

    Directory of Open Access Journals (Sweden)

    Tarandeep Kaur

    Full Text Available Lepidium latifolium Linn. (perennial pepperweed is one of the preferred phytofoods among cold arid region of Ladakh, India and its leaves contribute significantly to people's diet. This study was conducted to determine its nutritive value and antioxidant activity. Plant samples from three different locations were selected in the present study. Results showed that this plant is an excellent source of glucosinolates, notably sinigrin that is present in very high amount (∼70-90%. Its value ranged from 149 to 199 µg per g fresh weight. Fatty acid composition analysis showed that its leaves were abundant in unsaturated fatty acids, specifically linolenic acid (18∶3 whose percentage is about 50%. Higher glucose and crude protein along with higher nitrogen to sulfur ratio, supplements the nutritive value of this plant. Based on total phenol, flavanoids, free radical scavenging activity and DNA protective activity showed that this ecotype of perennial pepperweed contains high antioxidant properties. The percentage inhibition for O2(- scavenging activity ranged from 41.3% to 83.9%. Higher content of phenols (26.89 to 50.51 mg gallic acid equivalents per g dry weight and flavanoids (38.66 to 76.00 mg quercetin equivalents per g dry weight in leaves could be responsible for the free radical scavenging activity of this plant. Depending upon the location of the plants, variations were observed in different activities. Based on the systematic evaluation in this study, preparations of Lepidium latifolium from Ladakh can be promoted as substitute to dietary requirements.

  19. Antagonistic effect of Lepidium meyenii (red maca) on prostatic hyperplasia in adult mice.

    Science.gov (United States)

    Gonzales, G F; Gasco, M; Malheiros-Pereira, A; Gonzales-Castañeda, C

    2008-06-01

    The plants from the Lepidium gender have demonstrated to have effect on the size of the prostate. Lepidium meyenii (Maca) is a Peruvian plant that grows exclusively over 4000 m above sea level. The present study was designed to determine the effect of red maca (RM) in the prostate hyperplasia induced with testosterone enanthate (TE) in adult mice. Prostate hyperplasia was induced by administering TE, and then these animals (n = 6, each group) were treated with RM or Finasteride (positive control) for 21 days. There was an additional group without prostate hyperplasia (vehicle). Mice were killed on days 7, 14 and 21 after treatment with RM. Testosterone and oestradiol levels were measured on the last day of treatment. Prostatic stroma, epithelium and acini were measured histologically. RM reduced prostate weight at 21 days of treatment. Weights of seminal vesicles, testis and epididymis were not affected by RM treatment. The reduction in prostate size by RM was 1.59 times. Histological analysis showed that TE increased 2-fold the acinar area, effect prevented in the groups receiving TE + RM for 14 (P < 0.05) and 21 (P < 0.05) days and the group receiving TE + Finasteride for 21 days (P < 0.05). TE increased prostatic stroma area and this effect was prevented by treatment with RM since 7 days of treatment or Finasteride. The reduction in prostatic stroma area by RM was 1.42 times. RM has an anti-hyperplastic effect on the prostate of adult mice when hyperplasia was induced with TE acting first at prostatic stromal level.

  20. Fine-scale predictions of perennial pepperweed (Lepidium latifolium) invasion and herbicide success in a brackish tidal marsh

    OpenAIRE

    Tobias, Vanessa

    2015-01-01

    ABSTRACT Background/Question/Methods Perennial pepperweed (Lepidium latifolium, LELA) is an aggressively invasive crucifer that is a major concern for coastal management. This plant invades a wide variety of habitats including saline wetlands, riparian areas, and upland rangelands. Traditional management actions such as hand removal and mowing are impractical for controlling pepperweed in wetland habitats. Understanding the physical factors that influence invasion and the efficacy of herbi...

  1. Lepidium meyenii (Maca) enhances the serum levels of luteinising hormone in female rats.

    Science.gov (United States)

    Uchiyama, Fumiaki; Jikyo, Tamaki; Takeda, Ryosuke; Ogata, Misato

    2014-02-03

    Lepidium meyenii (Maca) is traditionally employed in the Andean region for its supposed fertility benefits. This study investigated the effect of Maca on the serum pituitary hormone levels during the pro-oestrus phase. Maca powder was made from the tubers of Lepidium meyenii Walp collected, dried, and reduced to powder at the plantation in Junín Plateau and was purchased from Yamano del Perú SAC. The Maca powder was identified by chemical profiling and taxonomic methods. Two groups of female Sprague-Dawley rats were provided feed with normal feed containing 5%, 25%, or 50% Maca powder ad libitum for 7 weeks. At 1800h of the proestrus stage, the rats were euthanised, and blood samples were collected for serum isolation. The serum pituitary hormone levels were measured using enzyme-linked immunosorbent assays (ELISAs). No significant differences in feed intake or growth rate were observed among the rats. During the pro-oestrus stage, a 4.5-fold increase (P<0.01) in luteinising hormone (LH) and a 19-fold increase (P<0.01) in follicle-stimulating hormone (FSH) were observed in the sera of rats fed with 50% Maca powder compared with the control rats. No significant differences were observed in the levels of the other pituitary hormones, including growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and thyroid-stimulating hormone (TSH). A dose-dependent increase of LH serum levels was observed within the range of 3-30g Maca/kg. Furthermore, the enhancement of the LH serum levels was specific to the pro-oestrus LH surge. The present study demonstrates that Maca uniquely enhances the LH serum levels of pituitary hormones in female rats during the pro-oestrus LH surge and acts in a pharmacological, dose-dependent manner. These findings support the traditional use of Maca to enhance fertility and suggest a potential molecular mechanism responsible for its effects. © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Caracterización de las proteínas totales de tres ecotipos de maca (Lepidium peruvianum G. Chacón), mediante electroforesis unidimensional y bidimensional

    OpenAIRE

    Mario Monteghirfo; Armando Yarleque-Chocas

    2007-01-01

    Objetivo: Caracterizar las proteínas solubles que se encuentran en la raíz del Lepidium peruvianum G. Chacón, maca, mediante electroforesis unidimensional y electroforesis bidimensional. Diseño: Estudio de tipo observacional y transversal. Lugar: Centro de Investigación de Bioquímica y Nutrición Alberto Guzmán Barrón. Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Lima, Perú. Materiales: Raíces de Lepidium peruvianum G. Chacón ‘maca’ de los ecotipos blanco, amarillo y morado,...

  3. Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior.

    Science.gov (United States)

    Lentz, Aaron; Gravitt, Karla; Carson, Culley C; Marson, Lesley

    2007-03-01

    The use of natural remedies for the treatment of sexual disorders is under current investigation. For generations people of the rural community in Peru have used Lepidium meyenii Walpers (Maca), because of their belief that it improves fertility and sexual desire. To determine the acute and chronic effects of Maca on male sexual behavior and to examine chronic administration of Maca on anxiety. Ejaculatory and mounting behavior and postejaculatory interval. Anxiety tests using an elevated plus maze, locomotion, and social interaction with another male. Maca (25 and 100 mg/kg) was orally administered to male rats for 30 days. Male sexual behavior was monitored after acute, 7 and 21 days of treatment. Anxiety behavior and locomotion were measured at 28-29 days using the elevated plus maze and social interaction tests. Maca treatment did not produce large changes in male sexual behavior. However, an increase in ejaculation latency and postejaculatory interval was observed after both acute and 7 days of treatment. After 21 days of treatment Maca had no effect on sexual behavior. Chronic administration of Maca did not increase locomotion or anxiety. Acute and short-term administration of Maca produced a small effect of rat male sexual behavior and long-term administration did not increase anxiety.

  4. Effect of three different cultivars of Lepidium meyenii (Maca) on learning and depression in ovariectomized mice.

    Science.gov (United States)

    Rubio, Julio; Caldas, Maria; Dávila, Sonia; Gasco, Manuel; Gonzales, Gustavo F

    2006-06-23

    Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4000 and 4500 m altitude in the central Peruvian Andes, particularly in Junin plateau and is used traditionally to enhance fertility. Maca is a cultivated plant and different cultivars are described according to the color of the hypocotyls. The study aimed to elucidate the effect of Yellow, Red and Black Maca on cognitive function and depression in ovariectomized (OVX) mice. In all experiments OVX mice were treated during 21 days and divided in four groups: control group, Yellow Maca, Red Maca and Black Maca. Latent learning was assessed using the water finding task and the antidepressant activity of the three varieties of Maca was evaluated using the forced swimming test. Animals were sacrificed at the end of each treatment and the uterus were excised and weighed. Black Maca was the variety that showed the best response in the water finding task, particularly in the trained mice. The three varieties were effective to reduce finding latency in non trained and trained mice (P < 0.05). In the force swimming test, all varieties assessed reduced the time of immobility and increased uterine weight in OVX mice. Black Maca appeared to have more beneficial effects on latent learning in OVX mice; meanwhile, all varieties of Maca showed antidepressant activity.

  5. Purification, characterization and biological activities of a polysaccharide from Lepidium meyenii leaves.

    Science.gov (United States)

    Li, Shufang; Hao, Limin; Kang, Qiaozhen; Cui, Yinxin; Jiang, Hui; Liu, Xin; Lu, Jike

    2017-10-01

    The characteristics and biological activities of a novel polysaccharide from Lepidium meyenii leaves (LMLP) were investigated. LMLP was purified using DEAE-52 cellulose chromatography followed by SephadexG-100 chromatography. The average molecule weight of LMLP was 58.43kDa and it was composed of galactose, arabinose, rhamnose, glucose and mannose with a relative molar ratio of 5.51:4.05:1.15:0.77:0.01. Antioxidant activity results showed that LMLP presented an EC 50 of 3.72mg/mL in scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical, and it also had reducing power (OD700nm being 0.079 at 1mg/mL). Moreover, LMLP possessed the potential on stimulating immune response of RAW264.7 cells. It could promote proliferation, strengthen phagocytosis function, enhance the expression of CD80, and increase the secretion of nitric oxide (NO) in a dose-dependent manner. All of these results suggested that LMLP could be used as a natural ingredient for functional food. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Lepidium meyenii (Maca) reduces spermatogenic damage induced by a single dose of malathion in mice.

    Science.gov (United States)

    Bustos-Obregon, Eduardo; Yucra, Sandra; Gonzales, Gustavo F

    2005-03-01

    To observe the effect of the aqueous extract of hypocotyls of the plant Lepidium meyenii (Maca) on spermatogenic damage induced by the organophosphate insecticide malathion in mice. Mice were treated with 80 mg/kg of malathion in the presence or absence of an aqueous extract of Maca, which was orally administered 7, 14 or 21 days after injection of the malathion. Stages of the seminiferous epithelium were assessed by transillumination on days 0, 7, 14 and 21. The administration of Maca increased significantly the length of stage VIII on days 7, 14 and 21 of treatment compared with the controls. An increase in the length of stage IX occurred on day 14 of treatment. Malathion affected spermatogenesis by reducing the lengths of stage IX on day 7, stages VII and IX-XI on day 14 and a recovery of stages IX-XII on day 21. The magnitude of alteration in the length of stage IX produced by malathion was significantly reduced by Maca on days 7 and 14. The length of stage VIII was increased when Maca was administered to mice treated with malathion. Assessment of the relative length of stages of the seminiferous epithelium showed that Maca treatment resulted in rapid recovery of the effect of malathion. Maca enhances spermatogenesis following spermatogenic damage caused by the organophosphorous pesticide.

  7. Maca (Lepidium meyenii) for treatment of menopausal symptoms: A systematic review.

    Science.gov (United States)

    Lee, Myeong Soo; Shin, Byung-Cheul; Yang, Eun Jin; Lim, Hyun-Ja; Ernst, Edzard

    2011-11-01

    Maca (Lepidium meyenii), an Andean plant of the brassica (mustard) family has been used for centuries in the Andes as an adaptogenic plant to manage anemia, infertility and female hormone balance. The aim of this review was to assess the evidence for and against the effectiveness of the maca plant as a treatment for menopausal symptoms. We searched 17 databases from their inception up to June 2011 and included all randomized clinical trials (RCTs) that compared any type of maca-based intervention to a placebo for the treatment of menopausal symptoms. All studies were assessed for methodological quality using the Cochrane 'risk of bias' assessment tool. Four RCTs met all inclusion criteria. These RCTs tested the effects of maca on menopausal symptoms in healthy perimenopausal, early postmenopausal, and late postmenopausal women. Using the Kupperman Menopausal Index and the Greene Climacteric Score, all RCTs demonstrated favorable effects of maca. There have been very few rigorous trials of maca for menopausal symptoms. The results of our systematic review provide limited evidence for the effectiveness of maca as a treatment for menopausal symptoms. However, the total number of trials, the total sample size, and the average methodological quality of the primary studies, were too limited to draw firm conclusions. Furthermore, the safety has not been proved yet. Therefore, the efficacy and safety should be tested in larger studies. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Effects of different varieties of Maca (Lepidium meyenii) on bone structure in ovariectomized rats.

    Science.gov (United States)

    Gonzales, Carla; Cárdenas-Valencia, Isaias; Leiva-Revilla, Johanna; Anza-Ramirez, Cecilia; Rubio, Julio; Gonzales, Gustavo F

    2010-01-01

    This study was designed to determine the effect of different varieties of maca (Lepidium meyenii) on bone structure in ovariectomized (OVX) rats. 36 female rats were randomly divided into 6 groups: sham and OVX rats treated with vehicle, estradiol (40 microg/kg), black, yellow or red maca (63 mg/ml) for 4 weeks. At the end of the treatment, uterine weight, femoral bone and lumbar vertebra histomorphology were assessed. Ovariectomy reduced weight, diameter and width of the femoral bone. Estradiol, black and red maca treatment reduced the effect of ovariectomy on these variables. Histological analyses revealed that estradiol, black and red maca treatments reversed the effect of ovariectomy by increasing the trabecular bone area in the second lumbar vertebra. Uterine weight was reduced in OVX rats, and estradiol but neither black nor red maca increased uterine weight. Red and black maca have protective effects on bone architecture in OVX rats without showing estrogenic effects on uterine weight. 2010 S. Karger AG, Basel.

  9. Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca), a Plant from the Peruvian Highlands.

    Science.gov (United States)

    Gonzales, Gustavo F

    2012-01-01

    Lepidium meyenii (maca) is a Peruvian plant of the Brassicaceae family cultivated for more than 2000 years, which grows exclusively in the central Andes between 4000 and 4500 m altitude. Maca is used as a food supplement and also for its medicinal properties described traditionally. Since the 90s of the XX century, an increasing interest in products from maca has been observed in many parts of the world. In the last decade, exportation of maca from Peru has increased from 1,415,000 USD in 2001 to USD 6,170,000 USD in 2010. Experimental scientific evidence showed that maca has nutritional, energizer, and fertility-enhancer properties, and it acts on sexual dysfunctions, osteoporosis, benign prostatic hyperplasia, memory and learning, and protects skin against ultraviolet radiation. Clinical trials showed efficacy of maca on sexual dysfunctions as well as increasing sperm count and motility. Maca is a plant with great potential as an adaptogen and appears to be promising as a nutraceutical in the prevention of several diseases.

  10. [Determination of benzyl glucosinolate in Lepidium meyenii from different regions by HPLC].

    Science.gov (United States)

    Tang, Lin; Yin, Hong-jun; Si, Cong-cong; Hu, Xiao-yan; Long, Zheng-hai

    2015-12-01

    The content of benzyl isothiocyanate (BITC) which as the enzymatic hydrolysis product of benzyl glucosinolate through thioglucosidase was determined by HPLC. The content of benzyl isothiocyanate (BITC) which as the enzymatic hydrolysis product of benzyl glucosinolate through thioglucosidase was determined by HPLC. The chromatography condition was as follows: Kaseisorb LC ODS 2000 (4.6 mm x 150 mm, 5 min) column with the mobile phase of acetonitrile(A)-water( B) under gradient elution (0-5 min, 3%-8% A; 5-9 min, 8%-48% A; 9-23 min, 48%-62% A; 23-28 min, 62%-99% A); the flow rate was 1.0 mL x min(-1) with 10 microL injection volume; detection wavelength was 246 nm and temperature of column was 40 degrees C. The content of benzyl glucosinolate was in the range of 10.76-17.91 g x L(-1). The method is simple, accurate and good reproducibility which can be used for the determination of benzyl glucosinolate in Lepidium meyenii, effectively.

  11. The use of maca (Lepidium meyenii) to improve semen quality: A systematic review.

    Science.gov (United States)

    Lee, Myeong Soo; Lee, Hye Won; You, Sooseong; Ha, Ki-Tae

    2016-10-01

    The aim of this review was to assess the evidence for the effectiveness of maca (Lepidium meyenii) in improving semen quality. We searched 11 databases from their inception to March 2016 and included all clinical trials on the improvement of semen quality parameters in infertile and healthy men, regardless of the study design or the type of maca. The risk of bias for each study was assessed using the Cochrane criteria. The selection of studies, data extraction, and validation were performed independently by the first two authors. Discrepancies were resolved through discussion by the same two authors. Five studies - 3 randomized clinical trials (RCTs) and 2 uncontrolled observational studies (UOSs) - met all of the inclusion criteria. One RCT found favorable effects of maca on sperm mobility in infertile men. The two other RCTs showed positive effects of maca on several semen quality parameters in healthy men. The two UOSs also suggested favorable effects of maca on semen quality. The results of our systematic review provide suggestive evidence for the effectiveness of maca in improving semen quality. However, the total number of trials, the total sample size, and the risk of bias of the included studies prevent the drawing firm conclusions. More rigorous studies are warranted. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Anti-fatigue activity of polysaccharide fractions from Lepidium meyenii Walp. (maca).

    Science.gov (United States)

    Li, Jing; Sun, Qingrui; Meng, Qingran; Wang, Lei; Xiong, Wentao; Zhang, Lianfu

    2017-02-01

    The two fractions of polysaccharide MPS-1 and MPS-2 were extracted from Lepidium meyenii Walp. (maca) by water, and purified using a DEAE-52 and a Sephadex G-100 column. The molecular weight (M W ) of MPS-1 was 7.6kDa, and the M W of MPS-2 was 6.7kDa. The MPS-1 was composed of xylose, arabinose, galactose and glucose, with the mole ratio 1:1.7:3.3:30.5; the MPS-2 was composed of arabinose, galactose and glucose, with the mole ratio 1:1.3:36.8. The IR spectrum implied that only α-pyranose existed in MPS-1, and both α-pyranose and β-pyranose existed in MPS-2. The anti-fatigue activities of MPS-1 and MPS-2 were measured by the forced swimming test, along with the determination of blood lactate (BLA), urea nitrogen (BUN), lactic dehydrogenase (LDH) activity and liver glycogen (LG). The results indicated that both MPS-1 and MPS-2 presented dose-dependently positive effects on the fatigue related parameters. Additionally, MPS-2 has a better anti-fatigue effect than MPS-1. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Effects on starch and amylolytic enzymes during Lepidium meyenii Walpers root storage.

    Science.gov (United States)

    Rondán-Sanabria, Gerby Giovanna; Valcarcel-Yamani, Beatriz; Finardi-Filho, Flavio

    2012-10-01

    The high water content in maca (Lepidium meyenii W.) roots combined with the damage produced during or after harvest makes them vulnerable to attack by enzymes and microorganisms. Although starch degradation has been extensively studied, in maca roots there is a paucity of research regarding the starch reserves. In this paper, parameters of starch degradation are shown to be related to the action of amylolytic enzymes during storage at room temperature. Over the course of three weeks, the starch and protein content, soluble sugar, total amylolytic activity, and α- and β-amylase activity were measured. In addition, the integrity of starch granules was observed by scanning electron microscopy. Despite the evidence of dehydration, there were no significant differences (p ≤ 0.5) in the total starch content or in the activities of α- and β-amylase. After the third week the roots remained suitable for consumption. The results indicate a postharvest latency that can lead to sprout or to senescence, depending on the environmental conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Effect of ethanolic extract of Lepidium meyenii Walp on serum hormone levels in ovariectomized rats.

    Science.gov (United States)

    Zhang, Yongzhong; Yu, Longjiang; Jin, Wenwen; Ao, Mingzhang

    2014-01-01

    To evaluate the effect of long-term ethanol extract of Lepidium meyenii (Maca) on serum hormone levels in ovariectomized (OVX) rats and compare them with the effect of diethylstilbestrol. Fifty female Sprague-Dawley rats were ovariectomized or sham operated. Both sham and OVX control groups (n = 10, respectively) received the vehicle. The remaining OVX rats were oral administrated with ethanol extract of Maca (0.096, or 0.24g/kg; n = 10, respectively) and diethylstilbestrol (0.05 mg/kg; n = 10). The treatment continued for 28 weeks. At week 12 and week 28, the blood of rats was collected and serum hormone levels, including estradiol (E2), testosterone (T) and follicle-stimulating hormone (FSH) were measured by radioimmunoassay. At week 12, the levels of serum E2 were slightly higher in Maca groups than that in OVX group; T levels were significantly decreased; and FSH levels were advanced slightly in Maca groups than that in sham group. After 28 weeks administration, serum E2 levels in Maca-treated animals did not differ significantly from sham control, the low dose of Maca increased serum E2 levels, and Maca prevented increase in serum FSH levels compared with OVX group. Long-term Maca supply modulates endocrine hormone balance in OVX rats, especially it decreases enhanced FSH levels. It is proposed that Maca may become a potential choice for postmenopausal women.

  15. Structure analysis and anti-fatigue activity of a polysaccharide from Lepidium meyenii Walp.

    Science.gov (United States)

    Tang, Yun; Zhu, Zhen-Yuan; Pan, Li-Chao; Sun, Huiqing; Song, Qiao-Ying; Zhang, Yongmin

    2018-03-16

    A polysaccharide was obtained from Lepidium meyenii Walp by hot water extraction and purification by Millipore (100 kD) and Sephadex G-200. The content of polysaccharide was examined to be 89.9% with phenol-sulfuric acid method. Its average molecular weight was estimated to be 2.213 × 10 6  Da by High Performance Gel Permeation Chromatography (HPGPC). Monosaccharide analysis showed that the polysaccharide was composed of arabinose, mannose, glucose and galactose with the molar ratio of 2.134: 1: 2.78: 2.82. After Smith degradation, methylation, infrared spectroscopy and NMR, the primary structure of the polysaccharide was identified. The backbone of the polysaccharide was composed of →4)-β-D-Galp-(1→ and →4)-α-D-Galp-(1→, while the branches were comprised of →6)-β-D-Glup-(1→, →5)- β-D-Araf-(1→, →3,6)-α-D-Manp-(1→, →3)-α-D-Galp-(1→, and α-D-Glup-(1→. The anti-fatigue effect of the polysaccharide was evaluated using exhaustive swimming test and biochemical indexes. The results indicated the polysaccharide has anti-fatigue effect.

  16. Metabolomic differentiation of maca (Lepidium meyenii) accessions cultivated under different conditions using NMR and chemometric analysis.

    Science.gov (United States)

    Zhao, Jianping; Avula, Bharathi; Chan, Michael; Clément, Céline; Kreuzer, Michael; Khan, Ikhlas A

    2012-01-01

    To gain insights on the effects of color type, cultivation history, and growing site on the composition alterations of maca (Lepidium meyenii Walpers) hypocotyls, NMR profiling combined with chemometric analysis was applied to investigate the metabolite variability in different maca accessions. Maca hypocotyls with different colors (yellow, pink, violet, and lead-colored) cultivated at different geographic sites and different areas were examined for differences in metabolite expression. Differentiations of the maca accessions grown under the different cultivation conditions were determined by principle component analyses (PCAs) which were performed on the datasets derived from their ¹H NMR spectra. A total of 16 metabolites were identified by NMR analysis, and the changes in metabolite levels in relation to the color types and growing conditions of maca hypocotyls were evaluated using univariate statistical analysis. In addition, the changes of the correlation pattern among the metabolites identified in the maca accessions planted at the two different sites were examined. The results from both multivariate and univariate analysis indicated that the planting site was the major determining factor with regards to metabolite variations in maca hypocotyls, while the color of maca accession seems to be of minor importance in this respect. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Isolation, purification, structural characterization and immunostimulatory activity of water-soluble polysaccharides from Lepidium meyenii.

    Science.gov (United States)

    Zha, Zhengqi; Wang, Su-Yan; Chu, Weihua; Lv, Yang; Kan, Hongjin; Chen, Qiuli; Zhong, Lili; Yue, Long; Xiao, Jinna; Wang, Ying; Yin, Hongping

    2018-03-01

    A water-soluble polysaccharide LMP-1 was isolated and purified by ion-exchange chromatography from maca (Lepidium meyenii Walp.). LMP-1 has a molecular weight of 1.01 × 10 4  Da, and is composed of glucose and arabinose with a molar ratio of 7.03:1.08. Methylation and the 1D and 2D NMR spectroscopy of LMP-1 revealed that it is mainly composed of →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →3)-α-D-Glcp-(1→, and β-D-Araf-(1→, with branching at O-6 of →4,6)-α-D-Glcp-(1 → . LMP-1 showed up-regulation of Toll-like receptor 4 (TLR4) and Toll-like receptor 2 (TLR2). The upstream proteins of Toll-like receptors (TLRs) (CD14 and MD2) and mRNA level of IL-1β also increased. Increased transcription factor nuclear factor-kappa B (NF-κB) p65 was found in the nuclei and cytoplasm in LMP-1-treated RAW264.7 macrophages. These results indicated that LMP-1 activated RAW264.7 macrophages and elicited immunostimulatory activities via the TLRs/NF-κB signalling pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Production of a new mucilage compound in Lepidium sativum callus by optimizing in vitro growth conditions.

    Science.gov (United States)

    Golkar, Pooran; Hadian, Fatemeh; Koohi Dehkordi, Mehrana

    2018-02-15

    The mucilage in Lepidium sativum L. is considered a biologically active compound with diverse medicinal properties. Different explants (hypocotyls and leaf) were transferred to Murashige and Skoog (MS) medium supplemented with twelve different plant growth regulator combinations under two different incubations (light and dark). The best mucilage production from callus (36.76% g g -1 dry weight) was obtained in the MS medium supplemented with 1 mg L -1 of 2, 4-D and 2 mg L -1 of BAP under the light condition. The mucilage produced by callus culture was nearly three times more than the mucilage yield of the seeds. The glucose, arabinose + mannose and galactose were 43.4 (mg g -1 DW), 195.3 (mg g -1 DW) and 86.2 (mg g -1 DW) in the mucilage originated from seed, callus leaf and callus hypocotyl, respectively. The present study proposes an efficient method for producing large scales of mucilage with a favorable sugar aimed at food or pharmaceutical industries.

  19. New Insight into the Water-Soluble Chlorophyll-Binding Protein from Lepidium virginicum.

    Science.gov (United States)

    Kell, Adam; Bednarczyk, Dominika; Acharya, Khem; Chen, Jinhai; Noy, Dror; Jankowiak, Ryszard

    2016-05-01

    This study describes new recombinant water-soluble chlorophyll (Chl)-binding proteins (WSCP) from Lepidium virginicum (LvWSCP). This complex binds four Chls (i.e. two dimers of Chls) per protein tetramer. We show that absorption, emission, hole-burned (HB) spectra and the shape of the zero-phonon hole (ZPH) action spectrum are consistent with the presence of uncorrelated excitation energy transfer between two Chl dimers. Thus, there is no need to include slow protein relaxation within the lowest excited state (as suggested in a previous analysis of cauliflower WSCP [Schmitt, F.-J. et al. (2008) J. Phys. Chem. B, 112, 13951; Pieper, J. et al. (2011) J. Phys. Chem. B, 115, 4053]) in order to explain the large shift observed between the maxima of the ZPH action and emission spectra. Experimental evidence is provided which shows that electron exchange between lowest energy Chls and the protein may occur, i.e. electrons can be trapped at low temperature by nearby aromatic amino acids. The latter explains the shape of nonresonant HB spectra (i.e. the absence of antihole), demonstrating that the hole-burning process in LvWSCP is largely photochemical in nature, though a small contribution from nonphotochemical hole burning (in resonant holes) is also observed. © 2016 The American Society of Photobiology.

  20. Chemical, physicochemical and spectrophotometric properties of crystalline chlorophyll-protein complexes from Lepidium virginicum L.

    Science.gov (United States)

    Murata, T; Ishikawa, C

    1981-04-13

    Two kinds of water-soluble chlorophyll-protein complexes were prepared from leaves of Lepidium virginicum L., one (CP661) from the plant cultivated in a green house from seeds collected near Mono Lake, CA, and the other (CP-663) from a plant collected at Narashino, Chiba, Japan, by ammonium sulfate fractionation followed by column chromatography on DEAE-cellulose and Sephacryl S-200. The chlorophyll . proteins were further purified by crystallization. CP661 has absorption peaks at 661, 468, 439, 419, 380, 339 and 272 nm. CP663 had absorption peaks at 663, 469, 438, 419, 379, 338 and 272 nm. Estimated molecular weights were 78 000 for CP661 and 80 000 for CP663 by gel filtration chromatography and 83 000 for CP661 and 107 000 for CP663 by an equilibrium sedimentation method. 1 mol chlorophyll . protein contained 4 mol chlorophyll a and b with ratios of 1.0 in CP661 and 1.6 to 1.9 in CP663, but no carotenoids. These characters are different from those of chlorophyll-protein complexes which are prepared from the thylakoid membranes of chloroplasts with detergents.

  1. Effect of salinity and ascorbic acid on growth, water and osmotic relations of Lepidium sativum

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    Azadeh Najjar-Khodabakhsh

    2015-06-01

    Full Text Available Soil salinity is a serious environmental problem in arid and semi-arid regions that have negative impacts on crop production. In this research, because of medicinal and nutritional importance of the garden cress (Lepidium sativum plant, the interactive effects of salinity (225 mM NaCl and ascorbic acid (1 mM were evaluated on growth and its water relations. A completely randomized design with four replications was conducted under controlled conditions. The results showed that salinity decreased growth, relative water content, osmotic potential and soluble proteins and increased soluble sugars, amino acids and proline contents. Many of salinity damaged characteristic were improved by adding exogenous ascorbic acid to salty environment. Exogenous ascorbic acid alone, in comparison with control, enhanced the growth of garden cress by increasing relative water content, soluble sugars and soluble proteins contents. The results indicated that usage of ascorbic acid, as an antioxidant, reduced harmful effects of salinity stress and led to growth improvement in garden cress plants.

  2. Isolation, purification and antioxidant activity of polysaccharides from the leaves of maca (Lepidium Meyenii).

    Science.gov (United States)

    Caicai, Kang; Limin, Hao; Liming, Zhang; Zhiqiang, Zheng; Yongwu, Yang

    2018-02-01

    Two fractions of polysaccharides (MLP-1 and MLP-2) were extracted from the leaves of maca (Lepidium Meyenii Walp.) by water, and purified using DEAE-52 ion exchange resin and sephadex G-200 clumns chromatography. An investigation was carried out for their structural characterization and antioxidant activity in vitro. The results indicated that MLP-1 was mainly composed of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose, with the molar ratio of 0.12:0.32:1.50:0.32:1.03:1.00:0.93; the MLP-2 was a homopolysaccharide composed of glucose. The molecular weight (Mw) of MLP-1 was 42756Da, and the Mw of MLP-2 was 93541Da. The FT-IR spectra showed the general characteristic absorption peak of maca leaf polysaccharides (MLPs). The evaluation of antioxidant activity revealed that MLP-1 had strong scavenging effects in vitro on hydroxyl, superoxide anion and DPPH radicals, whose EC 50 (mg/mL) was 0.44, 0.21, and 0.82, respectively. Both MLP-1 and MLP-2 presented dose-dependently positive effects on the antioxidant-related parameters. The results suggested that the purified MLP-1 displayed better antioxidant capacities than that of MLP-1, which could be explored as potential antioxidant agents for the complementary medicine or functional foods. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Protein changes in Lepidium sativum L. exposed to Hg during soil phytoremediation.

    Science.gov (United States)

    Smolinska, Beata; Szczodrowska, Agnieszka; Leszczynska, Joanna

    2017-08-03

    Some investigations have been carried out in this study to find the best technique of soil reclamation in mercurypolluted soil. In this study, we examined Lepidium sativum L. as a plant useful for Hg phytoextraction. The simultaneous application of compost and thiosulfate was explored as a possible method of enhancing the process of phytoextraction. The results of the investigations of plant protein changes during assisted Hg phytoextraction were also provided. The results of the study show that combined use of compost and thiosulfate significantly increased both the total Hg accumulation and its translocation to aerial plant tissues. Plant protein analysis showed that L. sativum L. has the ability to respond to environmental stress condition by the activation of additional proteins. The additional proteins, like homocysteine methyltransferase, ribulose bisphosphate carboxylases (long and short chains), 14-3-3-like protein, and biosynthesis-related 40S ribosomal protein S15, were activated in plant shoots only in experiments carried out in Hg-polluted soil. There were no protein changes observed in plants exposed to compost and thiosulfate. It suggests that the combined use of compost and thiosulfate decreased Hg toxicity.

  4. Antioxidative response of Lepidium sativum L. during assisted phytoremediation of Hg contaminated soil.

    Science.gov (United States)

    Smolinska, Beata; Szczodrowska, Agnieszka

    2017-09-25

    In this study, Lepidium sativum L. was used in repeated phytoextraction processes to remove Hg from contaminated soil, assisted by combined use of compost and iodide (KI). L. sativum L. is sensitive to changes in environmental conditions and has been used in environmental tests. Its short vegetation period and ability to accumulate heavy metals make it suitable for use in repeated phytoextraction. The antioxidant enzymatic system of the plant (catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and glutathione S-transferase (GST)) was analysed, to understand the effects of increasing Hg accumulation and translocation. Phytoextraction was repeated six times to decrease Hg contamination in soil, and the efficiency of each step was assessed. The results indicate that L. sativum L. is able to take up and accumulate Hg from contaminated soil. A corresponding increase in enzymatic antioxidants shows that the plant defence system is activated in response to Hg stress. Using compost and KI increases total Hg accumulation and translocation to the above-ground parts of L. sativum L. Repeating the process decreases Hg contamination in pot experiments in all variants of the process. The combined use of compost and KI during repeated phytoextraction increases the efficiency of Hg removal from contaminated soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Photosynthetic pigments and peroxidase activity of Lepidium sativum L. during assisted Hg phytoextraction.

    Science.gov (United States)

    Smolinska, Beata; Leszczynska, Joanna

    2017-05-01

    The study was conducted to evaluate metabolic answer of Lepidium sativum L. on Hg, compost, and citric acid during assisted phytoextraction. The chlorophyll a and b contents, total carotenoids, and activity of peroxidase were determined in plants exposed to Hg and soil amendments. Hg accumulation in plant shoots was also investigated. The pot experiments were provided in soil artificially contaminated by Hg and/or supplemented with compost and citric acid. Hg concentration in plant shoots and soil substrates was determined by cold vapor atomic absorption spectroscopy (CV-AAS) method after acid mineralization. The plant photosynthetic pigments and peroxidase activity were measured by standard spectrophotometric methods. The study shows that L. sativum L. accumulated Hg in its aerial tissues. An increase in Hg accumulation was noticed when soil was supplemented with compost and citric acid. Increasing Hg concentration in plant shoots was correlated with enhanced activation of peroxidase activity and changes in total carotenoid concentration. Combined use of compost and citric acid also decreased the chlorophyll a and b contents in plant leaves. Presented study reveals that L. sativum L. is capable of tolerating Hg and its use during phytoextraction assisted by combined use of compost and citric acid lead to decreasing soil contamination by Hg.

  6. Effect of three different cultivars of Lepidium meyenii (Maca on learning and depression in ovariectomized mice

    Directory of Open Access Journals (Sweden)

    Gonzales Gustavo F

    2006-06-01

    Full Text Available Abstract Background Lepidium meyenii Walp. (Brassicaceae, known as Maca, is a Peruvian hypocotyl growing exclusively between 4000 and 4500 m altitude in the central Peruvian Andes, particularly in Junin plateau and is used traditionally to enhance fertility. Maca is a cultivated plant and different cultivars are described according to the color of the hypocotyls. Methods The study aimed to elucidate the effect of Yellow, Red and Black Maca on cognitive function and depression in ovariectomized (OVX mice. In all experiments OVX mice were treated during 21 days and divided in four groups: control group, Yellow Maca, Red Maca and Black Maca. Latent learning was assessed using the water finding task and the antidepressant activity of the three varieties of Maca was evaluated using the forced swimming test. Animals were sacrificed at the end of each treatment and the uterus were excised and weighed. Results Black Maca was the variety that showed the best response in the water finding task, particularly in the trained mice. The three varieties were effective to reduce finding latency in non trained and trained mice (P Conclusion Black Maca appeared to have more beneficial effects on latent learning in OVX mice; meanwhile, all varieties of Maca showed antidepressant activity.

  7. Ethnobiology and Ethnopharmacology of Lepidium meyenii (Maca, a Plant from the Peruvian Highlands

    Directory of Open Access Journals (Sweden)

    Gustavo F. Gonzales

    2012-01-01

    Full Text Available Lepidium meyenii (maca is a Peruvian plant of the Brassicaceae family cultivated for more than 2000 years, which grows exclusively in the central Andes between 4000 and 4500 m altitude. Maca is used as a food supplement and also for its medicinal properties described traditionally. Since the 90s of the XX century, an increasing interest in products from maca has been observed in many parts of the world. In the last decade, exportation of maca from Peru has increased from 1,415,000 USD in 2001 to USD 6,170,000 USD in 2010. Experimental scientific evidence showed that maca has nutritional, energizer, and fertility-enhancer properties, and it acts on sexual dysfunctions, osteoporosis, benign prostatic hyperplasia, memory and learning, and protects skin against ultraviolet radiation. Clinical trials showed efficacy of maca on sexual dysfunctions as well as increasing sperm count and motility. Maca is a plant with great potential as an adaptogen and appears to be promising as a nutraceutical in the prevention of several diseases.

  8. Histología de la Maca, Lepidium meyenii Walpers (Brassicaceae

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    Manuel Marín-Bravo

    2013-06-01

    Full Text Available Se presenta el estudio histológico de Lepidium meyenii Walpers "maca", enfocado principalmente en la caracterización del órgano reservante. El estudio se realizó en macas de color amarillo, procedentes de Junín, y comprendió la caracterización histológica del órgano reservante subterráneo y detalles adicionales de la estructura interna foliar, a partir de muestras fijadas en FAA y empleando la técnica de inclusión en parafina. Los resultados muestran en el órgano reservante las características de una región de transición entre la raíz, de estructura secundaria lignificada, y el tallo primario reducido, con el desarrollo de una amplia zona medular. Presenta además un tipo peculiar de actividad cambial secundaria en la forma de haces conductores corticales. Entre los detalles histológicos adicionales está el desarrollo de una cubierta suberificada de células corticales en el órgano reservante y la presencia de tricomas cónicos unicelulares en las hojas.

  9. Preliminary approach to detect amylolytic and pectinolytic activities from maca (Lepidium meyenii Walp.) Ensaios preliminares de detecção de atividades amilolítica e pectinolítica em maca (Lepidium meyenii Walp.)

    OpenAIRE

    Gerby Giovanna Rondan-Sanabria; Tatiana da Costa Raposo Pires; Flavio Finardi Filho

    2006-01-01

    Amylase (AM), pectinesterase (PE) and polygalacturonase (PG) were extracted from maca roots (Lepidium meyenii Walp). The response surface model was used to determine the optimum conditions of pH and temperature activity of each enzyme on the crude extract. The highest values of AM activity occurred at pH 6.1 and 33.6 °C, very close to the experimental central point. The PE activity had a maximum activity at pH 6.6 and 49.4 and PG activity showed optimum activity at pH 5.4 and 46 °C.O ...

  10. Evaulation of perennial pepperweed (Lepidium latifolium) management in a seasonal wetland in San Francisco Estuary prior to restoration of tidal hydrology

    Science.gov (United States)

    Herbicide applications have shown potential for control and management of invasive perennial pepperweed (Lepidium latifolium) in rangelands and tidal wetlands. However, reported efficacy of management methods varies widely, and the effects of more recently labeled aquatic herbicides on non-target ve...

  11. Preliminary approach to detect amylolytic and pectinolytic activities from maca (Lepidium meyenii Walp. Ensaios preliminares de detecção de atividades amilolítica e pectinolítica em maca (Lepidium meyenii Walp.

    Directory of Open Access Journals (Sweden)

    Gerby Giovanna Rondan-Sanabria

    2006-03-01

    Full Text Available Amylase (AM, pectinesterase (PE and polygalacturonase (PG were extracted from maca roots (Lepidium meyenii Walp. The response surface model was used to determine the optimum conditions of pH and temperature activity of each enzyme on the crude extract. The highest values of AM activity occurred at pH 6.1 and 33.6 °C, very close to the experimental central point. The PE activity had a maximum activity at pH 6.6 and 49.4 and PG activity showed optimum activity at pH 5.4 and 46 °C.O objetivo do presente estudo foi determinar valores ideais de pH e temperatura para avaliar as atividades amilolítica (AM, pectinesterásica (PE e poligalacturonásica (PG em raízes de maca (Lepidium meyenii Walp.. Foi utilizado o modelo de superfície de resposta para atingir valores confiáveis de atividades enzimáticas em extratos brutos. Os valores máximos de atividade AM ocorreram em pH 6,1 a 33,6 °C, muito próximos do ponto central dos experimentos. Para as atividades de PE e PG, o valores ótimos foram atingidos em pHs 6,6 e 5,4, a 49,4 e 46 °C, respectivamente.

  12. Is the hype around the reproductive health claims of maca (Lepidium meyenii Walp.) justified?

    Science.gov (United States)

    Beharry, Shruti; Heinrich, Michael

    2018-01-30

    Maca - Lepidium meyenii Walp. has been cultivated and used by Andean people for over 1300-2000 years in Peru as food and medicine. Starting in the late 1990's it has developed into an important herbal medicine in China and is now cultivated there widely, too AIM OF STUDY: This study aims to provide an insight into the emergence of maca on the global market as an alternative remedy to treat reproductive health related problems in both men and women and to critically assess these health claims. A search of electronic databases such as EMBASE and a hand-search was done to acquire peer-reviewed articles and reports about maca. Lepidium meyenii is used traditionally as a tonic, fertility enhancer for both humans and cattle, and to treat a variety of ailments such as rheumatism, respiratory disorders and anaemia among others. Maca root is cooked, baked, fermented as a drink and made into porridge. In the last twenty years, maca was introduced onto the global market and demand has dramatically grown over this time with its promotion on the internet, as the 'Peruvian Ginseng' for libido and fertility enhancement. It has also been said to treat menopausal symptoms, erectile dysfunction and benign prostatic hyperplasia. The sky-rocketing demand for the plant has seen a shift from traditional cultivation methods to mass production practices with the use of fertilisers and also pesticides; as maca is now grown in areas other than the Andes such as in the Yunnan province in China. This can potentially affect the phytochemistry and composition of the plant and thus, the quality, safety and efficacy of maca products. Meanwhile, research into maca's medicinal properties has followed the spike in popularity of maca and has been focused mainly on maca's aphrodisiac and fertility enhancing properties. So far, the in vivo studies and clinical trials conducted have yielded inconclusive results. Some of the key limitations reside in methodology and sample size. Chemical profiling, led

  13. Lepidium meyenii (Maca increases litter size in normal adult female mice

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    Gasco Manuel

    2005-05-01

    Full Text Available Abstract Background Lepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age. Methods Adult female Balb/C mice were divided at random into three main groups: i Reproductive indexes group, ii Implantation sites group and iii Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment. Results Implantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group. Conclusion Administration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to

  14. Lepidium meyenii (Maca): a plant from the highlands of Peru--from tradition to science.

    Science.gov (United States)

    Gonzales, Gustavo F; Gonzales, Carla; Gonzales-Castañeda, Cynthia

    2009-12-01

    This review summarizes the current state of knowledge on Lepidium meyenii (maca), a cruciferous plant (Brassicaceae family) which is cultivated exclusively at an altitude of 4,000-4,500 m in the Peruvian Central Andes. Maca is traditionally used for its nutritional and presumed medicinal properties. Over the past 20 years, interest in maca has increased in many parts of the world, and since 2005 maca is considered one of the seven Peruvian flag products. Maca is exported as powder, capsules, pills, flour, liquor, and extracts. There are different types of maca with differ-ent colors ranging from white to black. We have studied the pharmacological effects of 3 types; yellow, black, and red maca. Evidence from experimental studies indicates effects of maca on nutrition, fertility, memory, and mood. Black maca has better effects on sperm production than yellow maca which has only moderate effects. Red maca, however, has no effect on sperm production. However, red maca has been shown to reduce prostate size in rats in which prostate hyperplasia had been induced with testosterone enanthate; yellow maca has shown moderate effects here, whereas black maca has not shown any effects. Randomized clinical trials have shown that maca has favorable effects on energy and mood, may decrease anxiety and improve sexual desire. Maca has also been shown to improve sperm production, sperm motility, and semen volume. Serum levels of testosterone, estradiol, LH, FSH, and prolactin were not affected. The exact mechanisms of action are still unclear, but so far research clearly indicates that various bioactive constituents contribute to the clinical effects reported.

  15. Structural Characterization and Antifatigue Effect In Vivo of Maca (Lepidium meyenii Walp) Polysaccharide.

    Science.gov (United States)

    Tang, Weimin; Jin, Lu; Xie, Lianghua; Huang, Juqing; Wang, Nan; Chu, Bingquan; Dai, Xulin; Liu, Yu; Wang, Rui; Zhang, Ying

    2017-03-01

    Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high-performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC-MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight-loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (M w ) of 793.5 kDa. It is composed of D-GalA: D-Glc: L-Ara: D-Man: D-Gal: L-Rha = 35.07:29.98:16.98:13.01:4.21:0.75 (mol, %). The findings revealed that MP contained β-1,3-Galp(A), β-1,3-Glcp, and α-1, 3-Manp linked alternatingly to form a backbone (5:4:1). MP (above mid-dosage 50 mg/kg bw/d) could effectively elongate swimming durations and accelerate average swimming speeds (within the 1st 5 min) of mice (P < 0.05) and improve the serous biochemical parameters of mice. Compared with the control model, high-dosage (100 mg/kg bw/d) MP treatment could significantly enhance glutathione peroxidase and creatine kinase activities (P < 0.05) and decreased lactate dehydrogenase activity (P < 0.01). High-dosage MP could significantly reduce the levels of blood urea nitrogen, lactic acid, and malondialdehyde (P < 0.05). MP is an acidic polysaccharide with a high D-GalA content, which could be responsible for the antifatigue effect of maca. © 2017 Institute of Food Technologists®.

  16. Inhibitory effect of a defensin gene from the Andean crop maca (Lepidium meyenii) against Phytophthora infestans.

    Science.gov (United States)

    Solis, Julio; Medrano, Giuliana; Ghislain, Marc

    2007-08-01

    In this study, we report the isolation of a defensin gene, lm-def, isolated from the Andean crop 'maca' (Lepidium meyenii) with activity against the pathogen Phytophthora infestans responsible of late blight disease of the potato and tomato crops. The lm-def gene has been isolated by polymerase chain reaction (PCR) using degenerate primers corresponding to conserved regions of 13 plant defensin genes of the Brassicaceae family assuming that defensin genes are highly conserved among cruciferous species. The lm-def gene belongs to a small multigene family of at least 10 members possibly including pseudogenes as assessed by genomic hybridization and nucleotide sequence analyses. The deduced mature Lm-Def peptide is 51 amino acids in length and has 74-94% sequence identity with other plant defensins of the Brassicaceae family. The Lm-Def peptide was produced as a fusion protein using the pET-44a expression vector and purified using an immobilized metal ion affinity chromatography. The recombinant protein (NusA:Lm-Def) exhibited in vitro activity against P. infestans. The NusA:Lm-Def protein caused growth inhibition and hyphal damage at concentration not greater than 0.4 microM. In contrast, the NusA protein alone expressed and purified similarly did not show any activity against P. infestans. Therefore, these results indicate that the lm-def gene isolated from maca belong to the plant defensin family with activity against P. infestans. Its expression in potato, as a transgene, might help to control the late blight disease caused by P. infestans with the advantage of being of plant origin.

  17. Effect of Black maca (Lepidium meyenii) on one spermatogenic cycle in rats.

    Science.gov (United States)

    Gonzales, G F; Nieto, J; Rubio, J; Gasco, M

    2006-10-01

    Lepidium meyenii (Maca) grows exclusively between 4000 and 4500 m above sea level in the Peruvian central Andes. The hypocotyls of this plant are traditionally used in the Andean region for their supposed fertility-enhancing properties. The hypocotyls have different colours. Of these, Black maca has better effects on spermatogenesis. The present study aimed to test the hypothesis that Black maca has early effects during a spermatogenic cycle (12 days) of male rats. For this, testicular spermatid, epididymal sperm and vas deferens sperm counts were measured after 1, 3, 5, 7 and 12 days of treatment with Black maca. Aqueous extract of Black maca was given orally by daily gavage at a dose of 2 g kg(-1). In a spermatogenic cycle, compared with day 1, daily sperm production (DSP) was lower at day 7 (control), whereas with Black maca, the difference was observed at day 12. Epididymal sperm count was higher in rats treated with Black maca at days 1, 3 and 7, but similar to controls at days 5 and 12; similarly sperm counts in vas deferens was higher in rats treated with Black maca in days 3, 5 and 7, but similar to controls at days 1 and 12. From this, it is suggested that first action of Black maca was at epididymal level increasing sperm count after 1 day of treatment, whereas an increase in sperm count was observed in vas deferens at day 3 of treatment. Finally, an increase in DSP was observed after 7 days of treatment with Black maca. Testicular testosterone was not affected after 7 days treatment with Black maca. In conclusion, Black maca affects sperm count as early as 1 day after beginning of treatment.

  18. Bioactive maca (Lepidium meyenii) alkamides are a result of traditional Andean postharvest drying practices.

    Science.gov (United States)

    Esparza, Eliana; Hadzich, Antonella; Kofer, Waltraud; Mithöfer, Axel; Cosio, Eric G

    2015-08-01

    Maca, Lepidium meyenii Walpers (Brassicaceae), is an annual herbaceous plant native to the high plateaus of the Peruvian central Andes. Its underground storage hypocotyls have been a traditional medicinal agent and dietary staple since pre-Columbian times. Reported properties include energizing and fertility-enhancing effects. Published reports have focused on the benzylalkamides (macamides) present in dry hypocotyls as one of the main bioactive components. Macamides are secondary amides formed by benzylamine and a fatty acid moiety, with varying hydrocarbon chain lengths and degree of unsaturation. Although it has been assumed that they are usually present in fresh undamaged tissues, analyses show them to be essentially absent from them. However, hypocotyls dried by traditional Andean postharvest practices or industrial oven drying contain up to 800μgg(-1) dry wt (2.3μmolg(-1) dry wt) of macamides. In this study, the generation of macamides and their putative precursors were studied during nine-week traditional drying trials at 4200m altitude and in ovens under laboratory conditions. Freeze-thaw cycles in the open field during drying result in tissue maceration and release of free fatty acids from storage and membrane lipids up to levels of 1200μgg(-1) dry wt (4.3μmolg(-1) dry wt). Endogenous metabolism of the isothiocyanates generated from glucosinolate hydrolysis during drying results in maximal benzylamine values of 4300μgg(-1) dry wt (40.2μmolg(-1) dry wt). Pearson correlation coefficients of the accumulation profiles of benzylamine and free fatty acid to that of macamides showed good values of 0.898 and 0.934, respectively, suggesting that both provide sufficient substrate for amide synthesis during the drying process. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Lepidium meyenii (Maca) increases litter size in normal adult female mice.

    Science.gov (United States)

    Ruiz-Luna, Ana C; Salazar, Stephanie; Aspajo, Norma J; Rubio, Julio; Gasco, Manuel; Gonzales, Gustavo F

    2005-05-03

    Lepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age. Adult female Balb/C mice were divided at random into three main groups: i) Reproductive indexes group, ii) Implantation sites group and iii) Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW) or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO) day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment. Implantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group. Administration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to enhance female fertility.

  20. Peruvian Maca (Lepidium peruvianum): (I) Phytochemical and Genetic Differences in Three Maca Phenotypes.

    Science.gov (United States)

    Meissner, Henry O; Mscisz, Alina; Mrozikiewicz, Mieczyslaw; Baraniak, Marek; Mielcarek, Sebastian; Kedzia, Bogdan; Piatkowska, Ewa; Jólkowska, Justyna; Pisulewski, Pawel

    2015-09-01

    Glucosinolates were previously reported as physiologically-important constituents present in Peruvian Maca (Lepidium peruvianum Chacon) and linked to various therapeutic functions of differently-colored Peruvian Maca hypocotyls. In two separate Trials, three colours of Maca hypocotyls "Black", "Red" and "Yellow" (termed "Maca phenotypes"), were selected from mixed crops of Peruvian Maca for laboratory studies as fresh and after being dried. Individual Maca phenotypes were cultivated in the highlands of the Peruvian Andes at 4,200m a.s.l. (Junin and Ninacaca). Glucosinolate levels, chromatographic HPLC profiles and DNA variability in the investigated Maca phenotypes are presented. Genotypic profiles were determined by the ISSR-PCR and RAPD techniques. Compared to the Black and Red phenotypes, the Yellow phenotype contained much lower Glucosinolate levels measured against Glucotropaeolin and m-methoxy-glucotropaeolin standards, and exhibited different RAPD and ISSR-PCR reactions. The Red Maca phenotype showed the highest concentrations of Glucosinolates as compared to the Black and Yellow Maca. It appears that the traditional system used by natives of the Peruvian Andean highlands in preparing Maca as a vegetable dish (boiling dried Maca after soaking in water), to supplement their daily meals, is as effective as laboratory methods - for extracting Glucosinolates, which are considered to be one of the key bioactive constituents responsible for therapeutic functions of Peruvian Maca phenotypes. It is reasonable to assume that the HPLC and DNA techniques combined, or separately, may assist in determining ID and "Fingerprints" identifying individual Peruvian Maca phenotypes, hence confirming the authenticity of marketable Maca products. The above assumptions warrant further laboratory testing.

  1. Lepidium meyenii (Maca) increases litter size in normal adult female mice

    Science.gov (United States)

    Ruiz-Luna, Ana C; Salazar, Stephanie; Aspajo, Norma J; Rubio, Julio; Gasco, Manuel; Gonzales, Gustavo F

    2005-01-01

    Background Lepidium meyenii, known as Maca, grows exclusively in the Peruvian Andes over 4000 m altitude. It has been used traditionally to increase fertility. Previous scientific studies have demonstrated that Maca increases spermatogenesis and epididymal sperm count. The present study was aimed to investigate the effects of Maca on several fertility parameters of female mice at reproductive age. Methods Adult female Balb/C mice were divided at random into three main groups: i) Reproductive indexes group, ii) Implantation sites group and iii) Assessment of uterine weight in ovariectomized mice. Animals received an aqueous extract of lyophilized Yellow Maca (1 g/Kg BW) or vehicle orally as treatment. In the fertility indexes study, animals received the treatment before, during and after gestation. The fertility index, gestation index, post-natal viability index, weaning viability index and sex ratio were calculated. Sexual maturation was evaluated in the female pups by the vaginal opening (VO) day. In the implantation study, females were checked for implantation sites at gestation day 7 and the embryos were counted. In ovariectomized mice, the uterine weight was recorded at the end of treatment. Results Implantation sites were similar in mice treated with Maca and in controls. All reproductive indexes were similar in both groups of treatment. The number of pups per dam at birth and at postnatal day 4 was significantly higher in the group treated with Maca. VO day occurred earlier as litter size was smaller. Maca did not affect VO day. In ovariectomized mice, the treatment with Maca increased significantly the uterine weights in comparison to their respective control group. Conclusion Administration of aqueous extract of Yellow Maca to adult female mice increases the litter size. Moreover, this treatment increases the uterine weight in ovariectomized animals. Our study confirms for the first time some of the traditional uses of Maca to enhance female fertility. PMID

  2. Uptake and phytotoxic effect of benzalkonium chlorides in Lepidium sativum and Lactuca sativa.

    Science.gov (United States)

    Khan, Adnan Hossain; Libby, Mark; Winnick, Daniel; Palmer, John; Sumarah, Mark; Ray, Madhumita B; Macfie, Sheila M

    2018-01-15

    Cationic surfactants such as benzalkonium chlorides (BACs) are used extensively as biocides in hospitals, food processing industries, and personal care products. BACs have the potential to reach the rooting zone of crop plants and BACs might thereby enter the food chain. The two most commonly used BACs, benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA), were tested in a hydroponic system to assess the uptake by and phytotoxicity to lettuce (Lactuca sativa L.) and garden cress (Lepidium sativum L.). Individually and in mixture, BACs at concentrations up to 100 mg L -1 did not affect germination; however, emergent seedlings were sensitive at 1 mg L -1 for lettuce and 5 mg L -1 for garden cress. After 12 d exposure to 0.25 mg L -1 BACs, plant dry weight was reduced by 68% for lettuce and 75% for garden cress, and symptoms of toxicity (necrosis, chlorosis, wilting, etc.) were visible. High performance liquid chromatography-mass spectroscopy analysis showed the presence of BACs in the roots and shoots of both plant species. Although no conclusive relationship was established between the concentrations of six macro- or six micro-nutrients, growth inhibition or BAC uptake, N and Mg concentrations in BAC-treated lettuce were 50% lower than that of control, indicating that BACs might induce nutrient deficiency. Although bioavailability of a compound in hydroponics is significantly higher than that in soil, these results confirm the potential of BACs to harm vascular plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Maca (Lepidium meyenii Walp, una revisión sobre sus propiedades biológicas

    Directory of Open Access Journals (Sweden)

    Gustavo F Gonzales

    Full Text Available La maca (Lepidium meyenii es una planta que crece sobre los 4000 metros de altitud en los Andes Centrales del Perú, presenta diferentes variedades de acuerdo al color de su hipocótilo. La presente revisión resume los resultados de estudios sobre los efectos de la maca en la función sexual, la espermatogénesis, la función reproductiva femenina, la memoria, la depresión y la ansiedad, como energizante y contra la hiperplasia benigna de próstata, osteoporosis y síndrome metabólico. Se discute también su efecto antienvejecimiento y la seguridad en su consumo. Se han demostrado diferencias en el efecto de las variedades negra, amarilla y roja de maca. La maca negra es la que mejores resultados presenta sobre la espermatogénesis, la memoria y contra la fatiga, mientras que la maca roja es la variedad que mejor revierte la hiperplasia benigna de próstata y la osteoporosis inducida experimentalmente. Además, la maca reduce los niveles de glucosa, y su consumo se relaciona con la reducción de la presión arterial y un mejor puntaje de salud. Estudios experimentales han demostrado que el consumo a corto como a largo plazo no muestra toxicidad tanto in vivo como in vitro. A pesar que los estudios experimentales han demostrado que la maca presenta diversos efectos benéficos, son necesarios más estudios clínicos para confirmar estos resultados

  4. Utilización de Lepidium Peruvianum Maca, como medio de cultivo para el crecimiento de Trypanosoma Cruzi

    Directory of Open Access Journals (Sweden)

    Charles Saldaña C

    2006-04-01

    Full Text Available Por sus características nutritivas de alto valor, se ensayó la posible utilidad del Lepidium peruvianum maca, como un medio para cultivar Trypanosoma cruzi. Bajo condiciones experimentales se procedió a incubar epimastigotes de T. cruzi en cuatro medios de cultivo bifásicos diferentes, a base de Lepidium peruvianum maca, los cuales fueron comparados con el medio de cultivo BHI como control. La incorporación de maca como medio de cultivo permitió el crecimiento de Trypanosoma cruzi; se determinó que el medio que contenía maca enriquecida con sangre entre los componentes sólidos y la infusión de maca en la fase líquida, presentó un mayor crecimiento (3,41 x 105 parásitos/mL con respecto a los otros medios de cultivo al quinto día (p<0,05.

  5. Actividad leishmanicida de los extractos metanólicos de cuatro ecotipos de Lepidium peruvianum, Chacón (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Libertad Alzamora

    2013-05-01

    Full Text Available El tratamiento clásico de la leishmaniosis cutánea consiste en la inyección de 15-20 ampollas de Glucantine lo que ocasiona efectos secundarios, este hecho justifica la búsqueda de nuevos medicamentos motivando la presente investigación. El objetivo fue evaluar in vitro la actividad leishmanicida de los extractos metanólicos (EM de los ecotipos blanco, rojo, morado y negro de Lepidium peruvianum, Chacón (también conocida como Lepidium meyenii Walp., sobre el crecimiento de Leishmania braziliensis peruviana. Los promastigotes alcanzaron la fase de crecimiento exponencial al quinto día de cultivo a 27 ºC en el medio bifásico Columbia, suplementado con 15% de sangre desfibrinada de carnero, en ese momento se enfrentaron, por separado, con los EM a concentraciones de 50, 100, 200 y 400 μg/ml. Los recuentos se hicieron diariamente con cámara Neubauer. La máxima disminución de promastigotes se produjo al segundo día de enfrentamiento para el ecotipo morado (17,41% de viabilidad empleando 400 μg/ml. El efecto leishmanicida estaría relacionado con los alcaloides imidazólicos presentes en el EM. Se concluye que al segundo día de enfrentamiento con el EM, el ecotipo morado presenta la mayor actividad leishmanicida seguido del ecotipo blanco.

  6. Effect of Lepidium meyenii (maca) on testicular function of mice with chemically and physically induced subfertility.

    Science.gov (United States)

    Valdivia Cuya, M; Yarasca De La Vega, K; Lévano Sánchez, G; Vásquez Cavero, J; Temoche García, H; Torres Torres, L; Cruz Ornetta, V

    2016-10-01

    The aim of this study was to evaluate the effect of Lepidium meyenii (maca) in chemically and physically subfertile mice. After 35 days, the following groups of mice were evaluated: control, sham, chemical subfertility, chemical subfertility-maca-supplemented, physical subfertility, physical subfertility-maca-supplemented and maca-supplemented only. Motility (32.36% ± 5.34%) and sperm count (44.4 ± 5.37 × 10(6) /ml) in the chemically and physically subfertile mice (11.81% ± 4.06%, 17.34 ± 13.07 × 10(6) /ml) decreased compared to the control (75.53% ± 2.97% and 57.4 ± 19.6 10(6) /ml) and sham (53.5% ± 7.86% and 58.4 ± 14.10 10(6) /ml). Maca was able to reverse the deleterious effect of motility (76.36 ± 1.97) as well as sperm count (53.5 ± 9.18 × 10(6) /ml) on chemical subfertility. In contrast, maca did not reverse the effects of induced physical subfertility nor motility (18.78% ± 14.41%) or sperm count (20.17 ± 11.20 × 10(6) /ml). The percentage of sperm DNA fragmentation in the physically subfertile mice increased (11.1% ± 19.29%) compared to the control (0.84% ± 0.85%). However, in the physically subfertile group, maca decreased sperm DNA fragmentation (2.29% ± 2.30%) closer to the sham (1.04% ± 0.62%) and the control (0.84% ± 0.85%). The group supplemented only with maca showed 0.54% ± 0.50% of spermatozoa with DNA fragmentation. Yet, the differences observed were statistically not significant. In conclusion, it appears that maca activates the cytochrome P450 system after chemically induced subfertility. However, it does not reverse the low mitochondrial membrane potential in spermatozoa compromised in the physical subfertility group. © 2016 Blackwell Verlag GmbH.

  7. Dormancy and germination in short-lived lepidium perfoliatu l. (brassicaceae) seeds

    International Nuclear Information System (INIS)

    Tang, An-Jun; Tian, M.; Long, Chun-Lin

    2010-01-01

    To understand germination timing in an ecological context, the response to environmental events that effect seed dormancy is central and has to be combined with knowledge of germination responses to different ecological factors. In this study, seed dormancy, germination and seedling survival of annual short-lived clasping pepper weed Lepidium perfoliatum L. (Brassicaceae) were investigated. Three types of pre-treatments viz., various temperature dry storage, light and water stress were tested as possible dormancy and survival-affecting environmental events. Fresh mature seeds were greatly dormant. Warm (30 deg. C) dry storage more facilitated breaking dormancy, they germinated well under apt conditions (e.g. 20 deg. C and 10/20 deg. C plus periodic light, 14 h/d). For those seeds which underwent after-ripening, they could germinate at a range of constant temperatures (4, 10, 15, 20, 25, and 30 deg. C) and one alternating temperature (10/20 deg. C). Under alternating temperature regimes, the final percent germination of L. perfoliatum seeds increased from 37 deg. C to 93% when temperature altered from 4/10 deg. C to 10/20 deg. C in light, then decreased with increasing temperature. The germination pattern under constant temperature conditions was similar to that under alternating temperature and significant differences in final percent germinations and rates of germination were observed among different temperatures. Under different light treatments, final germination of showed significant differences, only with 35% of germination percentage in dark, much lower than those in red and white light (i.e. 93% and 91%, respectively). GA3 could promote the germination of non-dormant seeds in dark. When water potentials were reduced, final percent germination decreased dramatically, and few seeds germinated at -0.98 MPa (generated by PEG-8000). The changes of proline content in resultant seedlings were reverse to that of final percent germination with changing water

  8. The Nutritional Composition of Maca in Hypocotyls (Lepidium meyenii Walp. Cultivated in Different Regions of China

    Directory of Open Access Journals (Sweden)

    Longfei Chen

    2017-01-01

    Full Text Available Maca (Lepidium meyenii Walp. was introduced to China in the recent two decades. Proximate compositions and secondary metabolites in dried maca tuber powders of different cultivation areas and colour types were analyzed and compared in order to provide the scientific guideline for its application. Cultivation region significantly affects the compositions of maca. The protein content of maca ranged from 9.31% to 21.02% by dry basis of maca powders and Xiaopingba-Y, Yulong-Y, and Pamirs-Y have the higher protein contents. The essential amino acids (EAA contents ranged from 189.19 to 312.90 mg/g protein. The crude lipid content of different maca ranged from 0.59% to 1.00% and has no significant difference (P>0.05. The total dietary fiber (TDF contents ranged from 17.82% to 26.00% and soluble dietary fiber (SDF ranged from 2.46% to 7.88%, respectively. Maca samples were rich in Na, Mg, Ca, and K elements which ranged 138.3–187.8, 625.2–837.2, 3838.9–4502.7, and 5394.8–8063.3 mg/kg dry matter (DM. Xiaopingba-Y has the highest benzyl glucosinolate content which was 2.31 mg/g DM. Peru-Y and Xiaopingba have the higher contents of total alkaloids contents which was 2.61 and 2.56 mg/kg DM. Yongsheng-Y, Yulong-Y, and Pamirs-Y were rich in N-benzyl hexadecanamide contents, which were 0.164, 0.174, and 0.173 mg/g DM, respectively. Significant higher protein, total dietary fiber, insoluble dietary fiber, total alkaloids, and benzyl glucosinolate contents were found in purple and black maca compared to yellow maca in Pamirs, while there was no significant difference in N-benzyl hexadecanamide content.

  9. Identification of maca (Lepidium meyenii Walp.) and its adulterants by a DNA-barcoding approach based on the ITS sequence.

    Science.gov (United States)

    Chen, Jin-Jin; Zhao, Qing-Sheng; Liu, Yi-Lan; Zha, Sheng-Hua; Zhao, Bing

    2015-09-01

    Maca (Lepidium meyenii) is an herbaceous plant that grows in high plateaus and has been used as both food and folk medicine for centuries because of its benefits to human health. In the present study, ITS (internal transcribed spacer) sequences of forty-three maca samples, collected from different regions or vendors, were amplified and analyzed. The ITS sequences of nineteen potential adulterants of maca were also collected and analyzed. The results indicated that the ITS sequence of maca was consistent in all samples and unique when compared with its adulterants. Therefore, this DNA-barcoding approach based on the ITS sequence can be used for the molecular identification of maca and its adulterants. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  10. Myrigalone A Inhibits Lepidium sativum Seed Germination by Interference with Gibberellin Metabolism and Apoplastic Superoxide Production Required for Embryo Extension Growth and Endosperm Rupture

    Czech Academy of Sciences Publication Activity Database

    Oracz, K.; Voegele, A.; Tarkowská, Danuše; Jacquemoud, D.; Turečková, Veronika; Urbanová, Terezie; Strnad, Miroslav; Sliwinska, E.; Leubner-Metzger, G.

    2012-01-01

    Roč. 53, č. 1 (2012), s. 81-95 ISSN 0032-0781 R&D Projects: GA AV ČR KAN200380801; GA MŠk ED0007/01/01; GA ČR GD522/08/H003 Keywords : Embryo cell extension growth * Endoreduplication * Endosperm rupture * Gibberellin metabolism * Lepidium sativum * Myrica gale * Phytotoxicity * Reactive oxygen species Subject RIV: EF - Botanics Impact factor: 4.134, year: 2012

  11. Effects of Lepidium meyenii Walp and Jatropha macrantha on blood levels of estradiol-17 beta, progesterone, testosterone and the rate of embryo implantation in mice.

    Science.gov (United States)

    Oshima, Masami; Gu, Yeunhwa; Tsukada, Sekihito

    2003-10-01

    The effects of two Peruvian folk medicines, Lepidium meyenii Walp and Jatropha macrantha, on mouse sex steroid hormones and embryo implantation were investigated. Progesterone levels increased significantly in mice that received L. meyenii Walp, while testosterone levels increased significantly in mice that received L. meyenii Walp as well as in those that received both L. meyenii Walp and J. macrantha. However, there were no marked changes in blood levels of estradiol-17beta or the rate of embryo implantation.

  12. Isolation of Crystalline Water-soluble Chlorophyll Proteins with Different Chlorophyll a and b Contents from Stems and Leaves of Lepidium virginicum

    OpenAIRE

    Reiko, Itoh; Shigeru, Itoh; Masaharu, Sugawa; Osamu, Oishi; Kenichi, Tabata; Mitsumasa, Okada; Mitsuo, Nishimura; Eijiro, Yakushiji; Department of Biology, Faculty of Science, Toho University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Toho University; Department of Biology, Faculty of Science, Kyushu University

    1982-01-01

    Two types of water-soluble chlorophyll proteins were isolated from Lepidium virginicum L. grown in Japan. The protein isolated from the leaves (CP663L) had a low chlorophyll a/b ratio (1.5-1.7), and that from the stems (CP663S) had a high ratio (3.4-3.5). CP663S showed the same crystal forms and almost the same molecular weight and subunit composition as CP663L.

  13. Therapeutic Effects of Pre-Gelatinized Maca (Lepidium Peruvianum Chacon) used as a Non-Hormonal Alternative to HRT in Perimenopausal Women - Clinical Pilot Study

    OpenAIRE

    Meissner, H. O.; Reich-Bilinska, H.; Mscisz, A.; Kedzia, B.

    2006-01-01

    Background: Roots of cruciferous plant Lepidium peruvianum Chacon cultivated in high plateaus of Andes and known under its common name Maca, have been traditionally-used as an energizing vegetable with therapeutic properties for both men and women. Maca has been recognized by natives of Peru as herbal remedy helping to treat conditions affecting menopausal women. Objective: The effects of Pre-Gelatinized Organic Maca (Maca-GO) on quantitative physiological responses and alleviation of symptom...

  14. Population.

    Science.gov (United States)

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  15. Improving the physical and moisture barrier properties of Lepidium perfoliatum seed gum biodegradable film with stearic and palmitic acids.

    Science.gov (United States)

    Seyedi, Samira; Koocheki, Arash; Mohebbi, Mohebbat; Zahedi, Younes

    2015-01-01

    Stearic and palmitic fatty acids (10%, 20% and 30%, W/W gum) were used to improve the barrier properties of Lepidium perfoliatum seed gum (LPSG) film. The impact of the incorporation of fatty acids into the film matrix was studied by investigating the physical, mechanical, and barrier properties of the films. Addition of stearic and palmitic fatty acids to LPSG films reduced their water vapor permeability (WVP), moisture content, water solubility and water adsorption. Increasing fatty acid concentration from 10% to 30%, reduced the elongation at break (EB). Lower values of tensile strength (TS) and elastic modulus (EM) were obtained in the presence of higher fatty acids concentrations. Incorporation of fatty acids led to production of opaque films and the opacity increased as function of fatty acids concentration. Results showed that moisture content, water solubility and WVP decreased as the chain length of fatty acid increased. Therefore, LPSG-fatty acids composite film could be used for packaging in which a low affinity toward water is needed. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. In silico profiling for secondary metabolites from Lepidium meyenii (maca) by the pharmacophore and ligand-shape-based joint approach.

    Science.gov (United States)

    Yi, Fan; Tan, Xiao-Lei; Yan, Xin; Liu, Hai-Bo

    2016-01-01

    Lepidium meyenii Walpers (maca) is an herb known as a traditional nutritional supplement and widely used in Peru, North America, and Europe to enhance human fertility and treat osteoporosis. The secondary metabolites of maca, namely, maca alkaloids, macaenes, and macamides, are bioactive compounds, but their targets are undefined. The pharmacophore-based PharmaDB targets database screening joint the ligand shape similarity-based WEGA validation approach is proposed to predict the targets of these unique constituents and was performed using Discovery Studio 4.5 and PharmaDB. A compounds-targets-diseases network was established using Cytoscape 3.2. These suitable targets and their genes were calculated and analyzed using ingenuity pathway analysis and GeneMANIA. Certain targets were identified in osteoporosis (8 targets), prostate cancer (9 targets), and kidney diseases (11 targets). This was the first study to identify the targets of these bioactive compounds in maca for cardiovascular diseases (29 targets). The compound with the most targets (46) was an amide alkaloid (MA-24). In silico target fishing identified maca's traditional effects on treatment and prevention of osteoporosis, prostate cancer, and kidney diseases, and its potential function of treating cardiovascular diseases, as the most important of this herb's possible activities.

  17. Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) enhances testicular gene expression of 3β-hydroxysteroid dehydrogenase in rats.

    Science.gov (United States)

    Ohta, Y; Kawate, N; Inaba, T; Morii, H; Takahashi, K; Tamada, H

    2017-12-01

    Although feeding diets containing the extract powder of Lepidium meyenii (maca), a plant growing in Peru's Central Andes, increases serum testosterone concentration associated with enhanced ability of testosterone production by Leydig cells in male rats, changes in testicular steroidogenesis-related factors by the maca treatment are not known. This study examined the effects of maca on testicular gene expressions for luteinizing hormone receptor, steroidogenic acute regulatory protein and steroidogenic enzymes. Eight-week-old male rats were given the diets with or without (control) the maca extract powder (2%) for 6 weeks, and mRNA levels were determined by reverse transcription quantitative real-time PCR. The results showed that the testicular mRNA level of HSD3B1 (3β-hydroxysteroid dehydrogenase; 3β-HSD) increased by the treatment, whereas the levels of the other factors examined did not change. These results suggest that increased expression of 3β-HSD gene may be involved in the enhanced steroidogenic ability by the maca treatment in rat testes. © 2017 Blackwell Verlag GmbH.

  18. Comparison of Mineral Element Content in a Functional Food Maca (Lepidium meyenii Walp.) from Asia and South America.

    Science.gov (United States)

    Zhang, Ji; Wang, Han-Mo; Zhao, Yan-Li; Zuo, Zhi-Tian; Wang, Yuan-Zhong; Jin, Hang

    2015-01-01

    Contents of eight mineral elements in maca (Lepidium meyenii Walp.) from China and Peru were determined by inductively coupled plasma optical emission spectroscopy. Cu contents in maca samples from China (2.5-31 mg kg(-1) dry weight, dw) were higher than the samples from Peru (<2.1 mg kg(-1) dw). Na in two samples from China was found to be significantly of high content (2400 and 2600 mg kg(-1) dw). The contents (mg kg(-1) dw) of B, Co, Cr, Li, Ni, and Zn were, respectively, 8.1-21, <0.023, <1.1~3.5, 0.020-0.17, 0.085-4.5, and 10-39 for the samples from China, while being 6.6-12, <0.023, <1.1~2.3, 0.035-0.063, 0.68-1.7, and 27-39 for the samples from Peru.

  19. Effect of butanolic fraction of yellow and black maca (Lepidium meyenii) on the sperm count of adult mice.

    Science.gov (United States)

    Inoue, N; Farfan, C; Gonzales, G F

    2016-10-01

    Lepidium meyenii, known as maca, is a popular nutraceutical food which is grown over 4,000 m above sea level in the Peruvian central highlands. Maca contains alkaloids, but there are no studies on their biological effects. The butanol fraction obtained from methanol extract of maca hypocotyls contains alkaloids. The effects of butanol/aqueous fractions partitioned from methanol extract of yellow and black maca were examined. Total phenolic content (TPC) and antioxidant capacity by 2,2'-diphenyl-1-picrylhydrazyl were used to evaluate maca fractions in vitro. Daily sperm production and sperm count in epididymis and vas deferens in mice were determined as biological effect of maca extracts in vivo. Yellow maca (21.7%±0.69) had better antioxidant capacity than black maca (18.2% ± 0.12; p < .01). Antioxidant activity was better in the methanolic fraction than in the aqueous fraction of yellow or black maca. TPC is higher in the aqueous fraction than in the methanolic extract of yellow or black maca. Black maca administration resulted in higher concentration of sperm count in epididymis and vas deferens compared to yellow maca. A higher biological effect was observed in methanolic extract and in aqueous extract than in the butanol fraction of maca. In conclusion, better biological effect was observed in the methanolic extract of maca than in its partitioned fractions. © 2016 Blackwell Verlag GmbH.

  20. Effect of red maca (Lepidium meyenii) on prostate zinc levels in rats with testosterone-induced prostatic hyperplasia.

    Science.gov (United States)

    Gonzales, C; Leiva-Revilla, J; Rubio, J; Gasco, M; Gonzales, G F

    2012-05-01

    Lepidium meyenii (maca) is a plant that grows exclusively above 4000 m in the Peruvian central Andes. Red maca (RM) extract significantly reduced prostate size in rats with benign prostatic hyperplasia (BPH) induced by testosterone enanthate (TE). Zinc is an important regulator of prostate function. This study aimed to determine the effect of RM on prostate zinc levels in rats with BPH induced by TE. Also, the study attempted to determine the best marker for the effect of RM on sex accessory glands. Rats treated with RM extract from day 1 to day 14 reversed the effect of TE administration on prostate weight and zinc levels. However, RM administered from day 7 to day 14 did not reduce the effect of TE on all studied variables. Finasteride (FN) reduced prostate, seminal vesicle and preputial gland weights in rats treated with TE. Although RM and FN reduced prostate zinc levels, the greatest effect was observed in TE-treated rats with RM from day 1 to day 14. In addition, prostate weight and zinc levels showed the higher diagnosis values than preputial and seminal vesicle weights. In conclusion, RM administered from day 1 to day 14 reduced prostate size and zinc levels in rats where prostatic hyperplasia was induced with TE. Also, this experimental model could be used as accurately assay to determine the effect of maca obtained under different conditions and/or the effect of different products based on maca. © 2011 Blackwell Verlag GmbH.

  1. Genome of Plant Maca (Lepidium meyenii) Illuminates Genomic Basis for High-Altitude Adaptation in the Central Andes.

    Science.gov (United States)

    Zhang, Jing; Tian, Yang; Yan, Liang; Zhang, Guanghui; Wang, Xiao; Zeng, Yan; Zhang, Jiajin; Ma, Xiao; Tan, Yuntao; Long, Ni; Wang, Yangzi; Ma, Yujin; He, Yuqi; Xue, Yu; Hao, Shumei; Yang, Shengchao; Wang, Wen; Zhang, Liangsheng; Dong, Yang; Chen, Wei; Sheng, Jun

    2016-07-06

    Maca (Lepidium meyenii Walp, 2n = 8x = 64), belonging to the Brassicaceae family, is an economic plant cultivated in the central Andes sierra in Peru (4000-4500 m). Considering that the rapid uplift of the central Andes occurred 5-10 million years ago (Ma), an evolutionary question arises regarding how plants such as maca acquire high-altitude adaptation within a short geological period. Here, we report the high-quality genome assembly of maca, in which two closely spaced maca-specific whole-genome duplications (WGDs; ∼6.7 Ma) were identified. Comparative genomic analysis between maca and closely related Brassicaceae species revealed expansions of maca genes and gene families involved in abiotic stress response, hormone signaling pathway, and secondary metabolite biosynthesis via WGDs. The retention and subsequent functional divergence of many duplicated genes may account for the morphological and physiological changes (i.e., small leaf shape and self-fertility) in maca in a high-altitude environment. In addition, some duplicated maca genes were identified with functions in morphological adaptation (i.e., LEAF CURLING RESPONSIVENESS) and abiotic stress response (i.e., GLYCINE-RICH RNA-BINDING PROTEINS and DNA-DAMAGE-REPAIR/TOLERATION 2) under positive selection. Collectively, the maca genome provides useful information to understand the important roles of WGDs in the high-altitude adaptation of plants in the Andes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Characteristic fingerprinting based on macamides for discrimination of maca (Lepidium meyenii) by LC/MS/MS and multivariate statistical analysis.

    Science.gov (United States)

    Pan, Yu; Zhang, Ji; Li, Hong; Wang, Yuan-Zhong; Li, Wan-Yi

    2016-10-01

    Macamides with a benzylalkylamide nucleus are characteristic and major bioactive compounds in the functional food maca (Lepidium meyenii Walp). The aim of this study was to explore variations in macamide content among maca from China and Peru. Twenty-seven batches of maca hypocotyls with different phenotypes, sampled from different geographical origins, were extracted and profiled by liquid chromatography with ultraviolet detection/tandem mass spectrometry (LC-UV/MS/MS). Twelve macamides were identified by MS operated in multiple scanning modes. Similarity analysis showed that maca samples differed significantly in their macamide fingerprinting. Partial least squares discriminant analysis (PLS-DA) was used to differentiate samples according to their geographical origin and to identify the most relevant variables in the classification model. The prediction accuracy for raw maca was 91% and five macamides were selected and considered as chemical markers for sample classification. When combined with a PLS-DA model, characteristic fingerprinting based on macamides could be recommended for labelling for the authentication of maca from different geographical origins. The results provided potential evidence for the relationships between environmental or other factors and distribution of macamides. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. Effects of a water extract of Lepidium meyenii root in different models of persistent pain in rats.

    Science.gov (United States)

    Tenci, Barbara; Di Cesare Mannelli, Lorenzo; Maresca, Mario; Micheli, Laura; Pieraccini, Giuseppe; Mulinacci, Nadia; Ghelardini, Carla

    2017-10-26

    Lepidium meyenii (Walp.), commonly called maca, is an Andean crop belonging to the Brassicaceae family. Maca hypocotils are habitually consumed as customary food as well as traditional remedies for pathological conditions such as infertility. Moreover, the characterization of maca extracts revealed the presence of compounds that are able to modulate the nervous system. Aimed to evaluate the efficacy of L. meyenii in persistent pain, the present study analyzed the effects of a commercial root extract from maca in different animal models reproducing the most common causes of chronic painful pathologies. A qualitative characterization of this commercial extract by high performance liquid chromatography-mass spectrometry and tandem mass spectrometry analyses allowed us to confirm the presence of some macamides known as bioactive constituents of this root and the absence of the main aromatic glucosinolates. The acute oral administration of maca extract is able to reduce mechanical hypersensitivity and postural unbalance induced by the intra-articular injection of monoiodoacetate and the chronic-constriction injury of the sciatic nerve. Furthermore, L. meyenii extract reverts pain threshold alterations evoked by oxaliplatin and paclitaxel. A good safety profile in mice and rats was shown. In conclusion, the present maca extract could be considered as a therapeutic opportunity to relieve articular and neuropathic pain.

  4. Dose-response effect of Red Maca (Lepidium meyenii) on benign prostatic hyperplasia induced by testosterone enanthate.

    Science.gov (United States)

    Gasco, M; Villegas, L; Yucra, S; Rubio, J; Gonzales, G F

    2007-08-01

    The main goal of this study was to determine the effect of a freeze-dried aqueous extract of the red variety of Lepidium meyenii (Red Maca) on testosterone-induced benign prostatic hyperplasia (BPH) in adult rats of the Holtzman strain. Rats were treated with freeze-dried aqueous extract of Red Maca at doses of 0, 0.01, 0.05, 0.1, and 0.5 g/kg body wt. A positive control group received Finasteride (0.6 mg/kg body wt.). After treatment, the animals were sacrificed, and the ventral prostate was extracted, and weighed. HPLC was used to determine the presence of glucosinolates in Red Maca. The prostate weight diminished in a dose-dependent fashion in rats treated with Red Maca. The effect of Red Maca was better than that observed with Finasteride. Finasteride, but not Red Maca, reduced seminal vesicles weight. Analysis of the HPLC indicated the presence of benzyl glucosinolate (Glucotropaeolin) with a content of 0.639%. Serum testosterone levels were not affected by Red Maca. Moreover, serum testosterone levels were not related to prostate or seminal vesicles weight in rats treated with vehicle and Red Maca. In conclusion, Red Maca administered orally in rats seems to exert an inhibitory effect at a level post DHT conversion, on the BPH-induced experimentally, although a direct measure of reductase action would still be required.

  5. Flavonolignans and other constituents from Lepidium meyenii with activities in anti-inflammation and human cancer cell lines.

    Science.gov (United States)

    Bai, Naisheng; He, Kan; Roller, Marc; Lai, Ching-Shu; Bai, Lu; Pan, Min-Hsiung

    2015-03-11

    From the roots of Lepidium meyenii Walpers (Brassicaceae) have been isolated and identified 2 flavonolignans, tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (1) and tricin 4'-O-(erythro-β-guaiacyl-glyceryl) ether (2), along with 11 other known compounds, tricin (3), pinoresinol (4), 4-hydroxycinnamic acid (5), guanosine (6), glucotropaeolin (7), desulfoglucotropaeolin (8), 3-hydroxybenzylisothiocyanate (9), malic acid benzoate (10), 5-(hydroxymethyl)-2-furfural (11), d-phenylalanine (12), and vanillic acid 4-O-β-d-glucoside (13). Structures were elucidated on the basis of NMR and MS data. Some isolates and previously isolated lepidiline B (14) were tested for cytotoxicity in a small panel of human cancer cell lines (Hep G2, COLO 205, and HL-60) and for anti-inflammatory activities in LPS-treated RAW 264.7 macrophage. Among them, compounds 1 and 14 were modestly active for inhibiting nitrite production in macrophage. Compounds 1, 14, and 3 were demonstrated to be selectively active against HL-60 cells with IC50 values of 40.4, 52.0, and 52.1 μM, respectively.

  6. マカ(Lepidium meyenii WALP)の成分分析法について

    OpenAIRE

    治京, 玉記

    2013-01-01

    (要旨)近年、原因療法を目的とした手法として、生理機能を調節する薬用植物が注目されている。アブラナ科植物マカLepidium meyenii WALPは、ペルーでは機能性の低下、更年期の諸症状や不妊などに用いられている伝統的な薬用植物である。しかしながら、マカは自然環境下で栽培されているため産地、栽培条件、収穫方法など環境変化により2次代謝産物への影響が懸念されている。本稿では、マカの2次代謝産物の成分分析法について報告する。...

  7. Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice.

    Science.gov (United States)

    Rubio, Julio; Dang, Haixia; Gong, Mengjuan; Liu, Xinmin; Chen, Shi-Lin; Gonzales, Gustavo F

    2007-10-01

    Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4,000 and 4,500 m altitude in the central Peruvian Andes, particularly in Junin plateau. Previously, Black variety of Maca showed to be more beneficial than other varieties of Maca on learning and memory in ovariectomized mice on the water finding test. The present study aimed to test two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of Black Maca administered for 35 days on memory impairment induced by scopolamine (1mg/kg body weight i.p.) in male mice. Memory and learning were evaluated using the water Morris maze and the step-down avoidance test. Brain acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in brain were also determined. Both extracts of Black Maca significantly ameliorated the scopolamine-induced memory impairment as measured in both the water Morris maze and the step-down avoidance tests. Black Maca extracts inhibited AChE activity, whereas MAO activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.

  8. Peruvian Maca (Lepidium peruvianum): (II) Phytochemical Profiles of Four Prime Maca Phenotypes Grown in Two Geographically-Distant Locations.

    Science.gov (United States)

    O Meissner, Henry; Mscisz, Alina; Piatkowska, Ewa; Baraniak, Marek; Mielcarek, Sebastian; Kedzia, Bogdan; Holderna-Kedzia, Elzbieta; Pisulewski, Pawel

    2016-03-01

    Peruvian Maca crops (Lepidium peruvianum), grown in two geographically-distant cultivation sites located at similar altitudes in the highlands of the Peruvian Andes (Junin at 4,200 m a.s.l. and Ancash 4,150 m a.s.l.), were used in the study. Four prime Maca phenotypes, distinguished by hypocotyl colours labelled as "Yellow", "Purple", "Red" and "Black" were selected to determine distribution in levels and corresponding ratios between individual Glucosinolates (Glucotropaeolin and m-methylglucotropaeolin) in an attempt to identify four Peruvian Maca phenotypes from analyses of powdered hypocotyls. There were highly significant differences (PMaca phenotypes harvested in two locations. The Junin crop represented a mostly "large" class (13.3 g) with "small" size hypocotyls (7.2 g), while a "small" class was predominant in Ancash (3.5 g). Powdered Yellow Maca showed significantly higher (PMaca being the least infected. Only minor, statistically-confirmed differences were detected in nutritive characteristics between the four Maca phenotypes grown in Junin, however highly significant differences (PMaca grown in Junin and Ancash. Irrespective of the cultivation location, Red phenotypes showed the highest content of Total Glucosinolates, followed by Black and Purple, with the Yellow phenotype showing consistently lower levels. Highly significant PMaca phenotypes grown in two locations, confirms an earlier assumption that sums of individual Glucosinolates, their ratios and profiles, may be feasible to explore in analytically identifying individual Maca phenotypes in pulverised marketed Maca products.

  9. Differentiation of the seed coat and composition of the mucilage of Lepidium perfoliatum L.: a desert annual with typical myxospermy.

    Science.gov (United States)

    Huang, Daihong; Wang, Cui; Yuan, Junwen; Cao, Jing; Lan, Haiyan

    2015-10-01

    Myxospermy is an important feature in seeds of many plant species grown in desert region. Fertilization can initiate differentiation of the seed coat epidermis into a specialized cell type with mucilage production. In the present study, comprehensive analyses were performed on the seed coat differentiation, mucilage production and composition, and seed germination in Lepidium perfoliatum (Brassicaceae), a desert annual with typical myxospermy in China. First, results indicated that mucilage was secreted uniformly at the outer tangential wall, resulting in compression of the cytoplasm to the bottom of the epidermal cells. Secondly, the inner tangential wall and two radial walls of the subepidermal cells were apparently thickened by production of a secondary cell wall material, which resulted in a 'typical' palisade appearance. Thirdly, immunohistochemical staining combined with the enzymatic digestion and infrared spectrum analysis of the mucilage indicated that, while one important component of the seed coat mucilage in L. perfoliatum was pectin, it also contained β-1,3-d-glucan and xyloglucan. Finally, seed germination showed that seeds with mucilage displayed significantly higher germination percentage than that of demucilaged seeds in abundant or excess water conditions. These results suggest that the possible ecological role of mucilage in L. perfoliatum is in the adaptation to habitats with well-watered and water-logged conditions, rather than water stress. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

  10. Evaluación preliminar del efecto de Lepidium meyenii Walp en el desarrollo embrionario de ratón

    Directory of Open Access Journals (Sweden)

    Guadalupe D´Arrigo

    2013-06-01

    Full Text Available La "maca", Lepidium meyenii Walp, especie vegetal nativa del Perú, es un recurso de gran valor nutricional. Además son varias las investigaciones realizadas en la última década en las cuales se ha comprobado sus efectos sobre la fertilidad de mamíferos. En este trabajo, evaluamos el posible efecto del extracto liofilizado del hipocótilo de L. meyenii Walp en el desarrollo de los embriones preimplantacionales de Mus musculus. Se suministró el liofilizado intra-peritonealmente, en una concentración de 0 g/Kg (grupo control y 1 g/Kg de peso corporal a dos grupos de ratonas preñadas respectivamente, desde el día 1 hasta el día 4 de preñez. Se evaluaron el estadío de desarrollo, condición y morfología embrionarias, no encontrándose efectos tóxicos del extracto acuoso liofilizado de "maca" en el desarrollo normal de los embriones pre-implantacionales de ratón.

  11. Comparison of Mineral Element Content in a Functional Food Maca (Lepidium meyenii Walp. from Asia and South America

    Directory of Open Access Journals (Sweden)

    Ji Zhang

    2015-01-01

    Full Text Available Contents of eight mineral elements in maca (Lepidium meyenii Walp. from China and Peru were determined by inductively coupled plasma optical emission spectroscopy. Cu contents in maca samples from China (2.5–31 mg kg−1 dry weight, dw were higher than the samples from Peru (<2.1 mg kg−1 dw. Na in two samples from China was found to be significantly of high content (2400 and 2600 mg kg−1 dw. The contents (mg kg−1 dw of B, Co, Cr, Li, Ni, and Zn were, respectively, 8.1–21, <0.023, <1.1~3.5, 0.020–0.17, 0.085–4.5, and 10–39 for the samples from China, while being 6.6–12, <0.023, <1.1~2.3, 0.035–0.063, 0.68–1.7, and 27–39 for the samples from Peru.

  12. Disminución del daño oxidativo y efecto hipoglicemiante de la maca (Lepidium meyenii Walp) en ratas con diabetes inducida por streptozotocina

    OpenAIRE

    María Elena Rodrigo; Rubén Valdivieso; Silvia Suárez; Rosa Oriondo; Raquel Oré

    2011-01-01

    Introducción: La maca es consumida desde tiempos ancestrales como parte de la dieta. Se le ha atribuido propiedades medicinales y se encuentra incluida en la medicina tradicional peruana. Estudios recientes describen que la admistración de maca reduce la glicemia en animales normoglicémicos, pero los mecanismos involucrados no están muy claros. Objetivos: Determinar el efecto hipoglicemiante y antioxidante de la harina de maca (Lepidium meyenii Walp) del ecotipo amarillo, en ratas con diabete...

  13. Disminucion del daño oxidativo y efecto hipoglicemiante de la maca (Lepidium meyenii Walp) en ratas con diabetes inducida por streptozotocina

    OpenAIRE

    Rodrigo, María Elena; Valdivieso, Rubén; Suárez, Silvia; Oriondo, Rosa; Oré, Raquel

    2013-01-01

    Introducción: La maca es consumida desde tiempos ancestrales como parte de la dieta. Se le ha atribuido propiedades medicinales y se encuentra incluida en la medicina tradicional peruana. Estudios recientes describen que la admistración de maca reduce la glicemia en animales normoglicémicos, pero los mecanismos involucrados no están muy claros. Objetivos: Determinar el efecto hipoglicemiante y antioxidante de la harina de maca (Lepidium meyenii Walp) del ecotipo amarillo, en ratas con diabete...

  14. Effect of Sodium Dodecyl Sulfate on Structure and Spectroscopic Characteristics of Water-Soluble Chlorophyll Protein Complex Isolated from Stems of Lepidium virginicum

    OpenAIRE

    Kenichi, Tabata; Shigeru, Itoh; Masaharu, Sugawa; Mitsuo, Nishimura; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University:(Present)National Institute for Basic Biology; Department of Biology, Faculty of Science, Kyushu University; Department of Biology, Faculty of Science, Kyushu University

    1983-01-01

    The relationship between structure and spectroscopic characteristics of the water-soluble chlorophyll protein complex isolated from stems of Lepidium virginicum (CP663S) was studied. Addition of 0.08% SDS induced a red shift of the 663 nm absorption maximum. At the same time, under excitation at 435 nm, the maximum of fluorescence emission shifted from 672 nm to 675 nm and the fluorescence yield increased. When CP663S was excited at 480 nm, the 660 nm emission band of chlorophyll b became mor...

  15. Effect of different fractions from hydroalcoholic extract of Black Maca (Lepidium meyenii) on testicular function in adult male rats.

    Science.gov (United States)

    Yucra, Sandra; Gasco, Manuel; Rubio, Julio; Nieto, Jessica; Gonzales, Gustavo F

    2008-05-01

    To evaluate the effect of different fractions of Black Maca (Lepidium meyenii), obtained from the hydroalcoholic extract, on spermatogenesis. Animal study. Animal and laboratory facilities at a university. Forty two adult male rats from the Holtzman strain (3 months old). Hydroalcoholic extract of Black Maca was partitioned with the following solvents: petroleum ether, chloroform, ethyl acetate, n-butanol, and water to obtain each fraction. Forty-two rats were divided in different groups according the fraction administered and vehicle. The hydroalcoholic extract of Black Maca and its fractions and vehicle were given orally by gavage for 7 days. Daily sperm production, epididymal sperm count, and sperm count in the vas deferens. Daily sperm production was higher in the ethyl acetate group compared with all other groups. The epididymal sperm count was higher in rats treated with ethyl acetate fraction compared with rats treated with vehicle (control), petroleum ether, n-butanol, or water fractions. The sperm count in vas deferens was lower in rats treated with ethyl acetate, petroleum ether, or water fractions compared with the control group; thus, the sperm count in vas deferens in rats treated with chloroform and n-butanol fractions was higher than in the petroleum ether group. The greatest effect on spermatogenesis was observed in the ethyl acetate fraction from the hydroalcoholic extract of Black Maca, suggesting that the compounds related to the beneficial effect on sperm production of Black Maca are presented in this fraction. Antioxidant components could play a role in the effect of increased epididymal sperm concentration observed in the model.

  16. Potent endogenous allelopathic compounds in Lepidium sativum seed exudate: effects on epidermal cell growth in Amaranthus caudatus seedlings

    Science.gov (United States)

    Iqbal, Amjad; Fry, Stephen C.

    2012-01-01

    Many plants exude allelochemicals – compounds that affect the growth of neighbouring plants. This study reports further studies of the reported effect of cress (Lepidium sativum) seed(ling) exudates on seedling growth in Amaranthus caudatus and Lactuca sativa. In the presence of live cress seedlings, both species grew longer hypocotyls and shorter roots than cress-free controls. The effects of cress seedlings were allelopathic and not due to competition for resources. Amaranthus seedlings grown in the presence of cress allelochemical(s) had longer, thinner hypocotyls and shorter, thicker roots – effects previously attributed to lepidimoide. The active principle was more abundant in cress seed exudate than in seedling (root) exudates. It was present in non-imbibed seeds and releasable from heat-killed seeds. Release from live seeds was biphasic, starting rapidly but then continuing gradually for 24 h. The active principle was generated by aseptic cress tissue and was not a microbial digestion product or seed-treatment chemical. Crude seed exudate affected hypocotyl and root growth at ∼25 and ∼450 μg ml−1 respectively. The exudate slightly (28%) increased epidermal cell number along the length of the Amaranthus hypocotyl but increased total hypocotyl elongation by 129%; it resulted in a 26% smaller hypocotyl circumference but a 55% greater epidermal cell number counted round the circumference. Therefore, the effect of the allelochemical(s) on organ morphology was imposed primarily by regulation of cell expansion, not cell division. It is concluded that cress seeds exude endogenous substances, probably including lepidimoide, that principally regulate cell expansion in receiver plants. PMID:22268144

  17. Evaluation of plant growth promoting activity and heavy metal tolerance of psychrotrophic bacteria associated with maca (Lepidium meyenii Walp. rhizosphere

    Directory of Open Access Journals (Sweden)

    Paola Ortiz-Ojeda

    2017-05-01

    Full Text Available The high Andean plateau of Peru is known to suffer harsh environmental conditions. Acidic soils containing high amount of heavy metals due to mining activities and withstanding very low temperatures affect agricultural activities by diminishing crop quality and yield. In this context, plant growth promoting rhizobacteria (PGPR adapted to low temperatures and tolerant to heavy metals can be considered as an environment-friendly biological alternative for andean crop management. The aim of this work was to select and characterize psychrotrophic PGPR isolated from the rhizosphere of maca (Lepidium meyenii Walp. a traditional andean food crop. A total of 44 psychrotrophic strains isolated from 3 areas located in the Bombon plateu of Junin-Peru were tested for their PGPR characteristics like indole acetic acid (IAA production, phosphate solubilization and for their ability to improve seed germination. In addition, their capacity to grow in the presence of heavy metals like cadmium (Cd, lead (Pb, cobalt (Co and mercury (Hg was tested. Of the total number of strains tested, 12 were positive for IAA production at 22 °C, 8 at 12 °C and 16 at 6 °C. Phosphate solubilization activities were higher at 12 °C and 6 °C than at 22 °C. Red clover plant assays showed that 16 strains were capable to improve seed germination at 22 °C and 4 at 12 °C. Moreover, 11 strains showed tolerance to Cd and Pb at varying concentrations. This study highlight the importance of obtaining PGPRs to be used in high andean plateu crops that are exposed to low temperatures and presence of heavy metals on soil.

  18. Beneficial effects of Lepidium meyenii (Maca) on psychological symptoms and measures of sexual dysfunction in postmenopausal women are not related to estrogen or androgen content.

    Science.gov (United States)

    Brooks, Nicole A; Wilcox, Gisela; Walker, Karen Z; Ashton, John F; Cox, Marc B; Stojanovska, Lily

    2008-01-01

    To examine the estrogenic and androgenic activity of Lepidium meyenii (Maca) and its effect on the hormonal profile and symptoms in postmenopausal women. Fourteen postmenopausal women completed a randomized, double-blind, placebo-controlled, crossover trial. They received 3.5 g/day of powered Maca for 6 weeks and matching placebo for 6 weeks, in either order, over a total of 12 weeks. At baseline and weeks 6 and 12 blood samples were collected for the measurement of estradiol, follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin, and the women completed the Greene Climacteric Scale to assess the severity of menopausal symptoms. In addition, aqueous and methanolic Maca extracts were tested for androgenic and estrogenic activity using a yeast-based hormone-dependent reporter assay. No differences were seen in serum concentrations of estradiol, follicle-stimulating hormone, luteinizing hormone, and sex hormone-binding globulin between baseline, Maca treatment, and placebo (P > 0.05). The Greene Climacteric Scale revealed a significant reduction in scores in the areas of psychological symptoms, including the subscales for anxiety and depression and sexual dysfunction after Maca consumption compared with both baseline and placebo (P Lepidium meyenii (Maca) (3.5 g/d) reduces psychological symptoms, including anxiety and depression, and lowers measures of sexual dysfunction in postmenopausal women independent of estrogenic and androgenic activity.

  19. Spread dynamics of perennial pepperweed (Lepidium latifolium) in two seasonal wetland areas

    Science.gov (United States)

    Renz, Mark J.; Steinmaus, Scott J.; Gilmer, David S.; DiTomaso, Joseph M.

    2012-01-01

    Perennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread, and determined the biotic and abiotic factors influencing the likelihood of invasion. The study was conducted at eight sites within two wetland regions of California. Results indicate that in undisturbed sites, spread was almost exclusively through vegetative expansion, and the average rate of spread was 0.85 m yr−1 from the leading edge. Spread in sites that were disked was more than three times greater than in undisturbed sites. While smaller infestations increased at a faster rate compared with larger populations, larger infestations accumulated more newly infested areas than smaller infestations from year to year. Stem density was consistently higher in the center of the infestations, with about 2.4 times more stems per square meter compared with the leading edge at the perimeter of the population. The invasion by perennial pepperweed was positively correlated with increased water availability but was negatively correlated with the cover of perennial and annual species. Thus, high cover of resident vegetation can have a suppressive effect on the rate of invasion, even in wetland ecosystems. On the basis of these results, we recommend that resident plant cover not be disturbed, especially in wet areas adjacent to areas currently infested with perennial pepperweed. For infested areas, management efforts should be prioritized to focus on controlling satellite populations as well as the leading edge of larger infestations first. This strategy could reduce the need for costly active restoration efforts by maximizing the probability of successful re-establishment of resident vegetation from the adjacent seedbank.

  20. Identification of endocannabinoid system-modulating N-alkylamides from Heliopsis helianthoides var. scabra and Lepidium meyenii.

    Science.gov (United States)

    Hajdu, Zsanett; Nicolussi, Simon; Rau, Mark; Lorántfy, László; Forgo, Peter; Hohmann, Judit; Csupor, Dezső; Gertsch, Jürg

    2014-07-25

    The discovery of the interaction of plant-derived N-alkylamides (NAAs) and the mammalian endocannabinoid system (ECS) and the existence of a plant endogenous N-acylethanolamine signaling system have led to the re-evaluation of this group of compounds. Herein, the isolation of seven NAAs and the assessment of their effects on major protein targets in the ECS network are reported. Four NAAs, octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid isobutylamide (1), octadeca-2E,4E,8E,10Z,14Z-pentaene-12-ynoic acid 2'-methylbutylamide (2), hexadeca-2E,4E,9Z-triene-12,14-diynoic acid isobutylamide (3), and hexadeca-2E,4E,9,12-tetraenoic acid 2'-methylbutylamide (4), were identified from Heliopsis helianthoides var. scabra. Compounds 2-4 are new natural products, while 1 was isolated for the first time from this species. The previously described macamides, N-(3-methoxybenzyl)-(9Z,12Z,15Z)-octadecatrienamide (5), N-benzyl-(9Z,12Z,15Z)-octadecatrienamide (6), and N-benzyl-(9Z,12Z)-octadecadienamide (7), were isolated from Lepidium meyenii (Maca). N-Methylbutylamide 4 and N-benzylamide 7 showed submicromolar and selective binding affinities for the cannabinoid CB1 receptor (Ki values of 0.31 and 0.48 μM, respectively). Notably, compound 7 also exhibited weak fatty acid amide hydrolase (FAAH) inhibition (IC50 = 4 μM) and a potent inhibition of anandamide cellular uptake (IC50 = 0.67 μM) that was stronger than the inhibition obtained with the controls OMDM-2 and UCM707. The pronounced ECS polypharmacology of compound 7 highlights the potential involvement of the arachidonoyl-mimicking 9Z,12Z double-bond system in the linoleoyl group for the overall cannabimimetic action of NAAs. This study provides additional strong evidence of the endocannabinoid substrate mimicking of plant-derived NAAs and uncovers a direct and indirect cannabimimetic action of the Peruvian Maca root.

  1. Antioxidant and neuroprotector effect of Lepidium meyenii (maca) methanol leaf extract against 6-hydroxy dopamine (6-OHDA)-induced toxicity in PC12 cells.

    Science.gov (United States)

    Rodríguez-Huamán, Ángel; Casimiro-Gonzales, Sandra; Chávez-Pérez, Jorge Antonio; Gonzales-Arimborgo, Carla; Cisneros-Fernández, Richard; Aguilar-Mendoza, Luis Ángel; Gonzales, Gustavo F

    2017-05-01

    Reactive oxygen species (ROS) are normally produced during cell metabolism, there is strong evidence to suggest that ROS produced in excess impair the cell and may be etiologically related to various neurodegenerative diseases. This study was undertaken to examine the effects of Lepidium meyenii (MACA) methanol leaf extract on neurotoxicity in PC12 cell exposed to 6-hydroxydopamine (6-OHDA). Fresh samples of "maca" leaves were processed in order to obtain foliar extracts and to evaluate the neurobiological activity on PC12 cells, subjected to the cytotoxic effect of 6-OHDA through the determination of the capacity antioxidant, cell viability and cytotoxicity assays on PC12 cells. The results of the tests of antioxidant activity, showed maximum values of 2262.37 and 1305.36 expressed in Trolox equivalents (TEAC), for the methanolic and aqueous fractions respectively. Cell viability assays at a dose of 10 μg extract showed an increase of 31% and 60% at 6 and 12 h of pretreatment, respectively. Cytotoxicity assays at the same dose and exposure time showed a 31.4% and 47.8% reduction in lactate dehydrogenase (LDH) activity and an increase in superoxide dismutase (SOD) activity. The results allow us to affirm that the methanolic foliar extract of "maca" presents in vitro neurobiological activity of antioxidant protection, increase in cell viability and reduction of cytotoxicity against oxidative stress generated by 6-OHDA. In conclusion, the present study shows a protective role for Lepidium meyenii leaf extract on 6-OHDA-induced toxicity by an antioxidant effect.

  2. Red Maca (Lepidium meyenii), a Plant from the Peruvian Highlands, Promotes Skin Wound Healing at Sea Level and at High Altitude in Adult Male Mice.

    Science.gov (United States)

    Nuñez, Denisse; Olavegoya, Paola; Gonzales, Gustavo F; Gonzales-Castañeda, Cynthia

    2017-12-01

    Nuñez, Denisse, Paola Olavegoya, Gustavo F. Gonzales, and Cynthia Gonzales-Castañeda. Red maca (Lepidium meyenii), a plant from the Peruvian highlands, promotes skin wound healing at sea level and at high altitude in adult male mice. High Alt Med Biol 18:373-383, 2017.-Wound healing consists of three simultaneous phases: inflammation, proliferation, and remodeling. Previous studies suggest that there is a delay in the healing process in high altitude, mainly due to alterations in the inflammatory phase. Maca (Lepidium meyenii) is a Peruvian plant with diverse biological properties, such as the ability to protect the skin from inflammatory lesions caused by ultraviolet radiation, as well as its antioxidant and immunomodulatory properties. The aim of this study was to determine the effect of high altitude on tissue repair and the effect of the topical administration of the spray-dried extract of red maca (RM) in tissue repair. Studies were conducted in male Balb/c mice at sea level and high altitude. Lesions were inflicted through a 10 mm-diameter excisional wound in the skin dorsal surface. Treatments consisted of either (1) spray-dried RM extract or (2) vehicle (VH). Animals wounded at high altitude had a delayed healing rate and an increased wound width compared with those at sea level. Moreover, wounding at high altitude was associated with an increase in inflammatory cells. Treatment with RM accelerated wound closure, decreased the level of epidermal hyperplasia, and decreased the number of inflammatory cells at the wound site. In conclusion, RM at high altitude generate a positive effect on wound healing, decreasing the number of neutrophils and increasing the number of macrophages in the wound healing at day 7 postwounding. This phenomenon is not observed at sea level.

  3. Efecto de cuatro ecotipos de Lepidium peruvianum Chacón sobre la producción de óxido nítrico in vitro

    Directory of Open Access Journals (Sweden)

    Libertad Alzamora

    2013-05-01

    Full Text Available Los macrófagos desempeñan un rol importante en la respuesta innata y adaptativa, durante su activación producen mediadores citotóxicos como Óxido Nítrico (NO. El objetivo fue evaluar la producción de NO por macrófagos peritoneales de ratón cultivados con extractos metanólicos (EM de los ecotipos rojo, negro, morado y blanco de Lepidium peruvianum Chacón (también conocida como Lepidium meyenii Walp. Los EM se prepararon empleando maca pulverizada macerada en metanol (1:2 durante 10 días. Los macrófagos peritoneales se obtuvieron de ratones 3 días después de haberles inyectado 1 ml de Caldo Tioglicolato por vía intraperitoneal; se cultivaron por triplicado durante 18 h a 37 °C en medio RPMI 1640 suplementado con 10% de suero de bovino fetal. La dosis de EM fue de 800 μg/ml por ecotipo, se consideraron controles sin EM. La producción de NO se determinó por acumulación de nitrito en el medio y se evidenció con el reactivo de Peter Griess, las concentraciones de nitrito se calcularon en base a la curva estándar elaborada con NaNO2. Las concentraciones producidas de nitrito fueron de 7,45; 6,79; 5,76; 5,61 y 6,81 mM para los EM de los ecotipos morado, negro, blanco, rojo y control respectivamente. Los cuatro ecotipos indujeron la producción de NO, aunque con el ecotipo morado fue superior (p>0,05.

  4. Producción de IFN−γ en cultivos de linfocitos humanos por efecto de los extractos metanólicos de cuatro ecotipos de Lepidium peruvianum, Chacón (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Libertad Alzamora

    2013-05-01

    Full Text Available Se estudió la actividad inmunoduladora sobre cultivos de linfocitos T humanos de sangre periférica. Se evaluó la producción de IFN−γ inducida por los extractos metanólicos (EM de los ecotipos blanco, negro, rojo y morado de Lepidium peruvianum (conocida también como Lepidium meyenii Walp. maca. Luego de cultivar los linfocitos con los respectivos EM de maca durante 14 horas sólo el EM del ecotipo morado indujo la producción significativa de IFN−γ cuantificada mediante Elispot. El extracto metanólico del ecotipo morado de maca posee propiedades inmunoestimuladoras importantes, desencadenando la activación de linfocitos T humanos.

  5. Effect of organic fertilizers on quality and quantity characteristics of blond psyllium (Plantago ovata Forssk.) clasping peperweed (Lepidium perfoilatum L.), qodumeh Shirazi (Alyssum homolocarpum L.) and dragon's head (Lalementia iberica L.)

    OpenAIRE

    A. Koocheki; S. Amirmoradi; J. Shabahng; S. Kalantari Khandani

    2016-01-01

    This experiment was carried out in experimental farm of Agricultural Faculty of Ferdowsi University of Mashhad, Iran during 2010. The design was split plot with three replications. Main plots were the medicinal plant species consist of: blond psyllium (Plantago ovate Forssk.), clasping peperweed (Lepidium perfoilatum L.), qodumeh Shirazi (Alyssum homolocarpum L.) dragon's head (Lalementia iberica L.) and subplots were various organic fertilizer consist of cow manure, vermicompost (based on c...

  6. Toxicological aspects of the South American herbs cat's claw (Uncaria tomentosa) and Maca (Lepidium meyenii) : a critical synopsis.

    Science.gov (United States)

    Valerio, Luis G; Gonzales, Gustavo F

    2005-01-01

    Recent exceptional growth in human exposure to natural products known to originate from traditional medicine has lead to a resurgence of scientific interest in their biological effects. As a strategy for improvement of the assessment of their pharmacological and toxicological profile, scientific evidence-based approaches are being employed to appropriately evaluate composition, quality, potential medicinal activity and safety of these natural products. Using this approach, we comprehensively reviewed existing scientific evidence for known composition, medicinal uses (past and present), and documented biological effects with emphasis on clinical pharmacology and toxicology of two commonly used medicinal plants from South America with substantial human exposure from historical and current global use: Uncaria tomentosa (common name: cat's claw, and Spanish: uña de gato), and Lepidium meyenii (common name: maca). Despite the geographic sourcing from remote regions of the tropical Amazon and high altitude Andean mountains, cat's claw and maca are widely available commercially in industrialised countries. Analytical characterisations of their active constituents have identified a variety of classes of compounds of toxicological, pharmacological and even nutritional interest including oxindole and indole alkaloids, flavonoids, glucosinolates, sterols, polyunsaturated fatty acids, carbolines and other compounds. The oxindole alkaloids from the root bark of cat's claw are thought to invoke its most widely sought-after medicinal effects as a herbal remedy against inflammation. We find the scientific evidence supporting this claim is not conclusive and although there exists a base of information addressing this medicinal use, it is limited in scope with some evidence accumulated from in vitro studies towards understanding possible mechanisms of action by specific oxindole alkaloids through inhibition of nuclear factor (NF)-kappaB activation. Although controlled clinical

  7. Ameliorative effect of Draba nemorosa extract on chronic heart ...

    African Journals Online (AJOL)

    that TCM effectively treats symptoms, reduce side effects and reverse resistance via targeting multiple pathways. TCMs such as Shengmai [9],. Sini decoction [10], Shuanglong formula [11], and. Huangqi injection have been reported to exhibit potential pharmacological activities against cardiovascular diseases [12].

  8. Efecto neuroprotector del Lepidium meyenii, ecotipo negro (maca negra) en ratas crías frente al daño cerebral inducido por la ingesta de sulfato ferroso y vitamina C durante la gestación de las ratas madre

    OpenAIRE

    Troncoso, Luzmila; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Guija, Emilio; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Palomino, Felio; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Soberón, Mercedes; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Oliveira, Gisela; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Núñez, Marco; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Flores, Juana; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Acuña, Sheresnarda; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú; Terrazas, Carmen; Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM. Lima, Perú

    2013-01-01

    Objetivo: Evaluar el efecto neuroprotector del Lepidium meyenii, ecotipo negro en ratas crías por ingesta de sulfato ferroso y vitamina C (SFC) durante la gestación de ratas madre. Diseño: Experimental, analítico. Institución: Centro de Investigación de Bioquímica y Nutrición. Material biológico: Lepidium meyenii, ecotipo negro (maca negra: MN), ratas. Intervenciones: Se distribuyeron 30 ratas albinas de dos meses de edad, en tres grupos. Tratamiento en los últimos 7 días de gestación: grupo ...

  9. Effect of chronic treatment with three varieties of Lepidium meyenii (Maca) on reproductive parameters and DNA quantification in adult male rats.

    Science.gov (United States)

    Gasco, M; Aguilar, J; Gonzales, G F

    2007-08-01

    The aim of this study was to evaluate the chronic effect of different varieties of Lepidium meyenii (Red Maca, Yellow Maca and Black Maca). Male rats were treated by gavage with aqueous extract of each variety of maca equivalent to 1 g hypocotyl kg(-1) body weight (BW) for 84 days. At the end of the treatment, daily sperm production (DSP), epididymal sperm count (ESC) and sperm count in vas deferens (SCVD) were assessed. In addition, testis DNA quantification was also determined. Any toxic effect was assessed in liver and spleen by histological studies. The results indicate that Yellow Maca and Black Maca improved ESC and that three varieties of maca increased the SCVD without affecting DSP. Moreover, testis DNA levels were not affected by treatment with any of the three varieties of maca. Histological picture of the liver in animals treated with the three varieties of maca was similar to that observed in controls. In conclusion, Yellow and Black Maca increased epididymal sperm count after 84 days of treatment without affecting DSP. Maca seems to act as a modulator of sperm count at the reproductive tract level.

  10. Hypocotyls of Lepidium meyenii (maca), a plant of the Peruvian highlands, prevent ultraviolet A-, B-, and C-induced skin damage in rats.

    Science.gov (United States)

    Gonzales-Castañeda, Cynthia; Gonzales, Gustavo F

    2008-02-01

    Lepidium meyenii (maca) is a plant that grows exclusively in the Peruvian Central Andes, where ultraviolet radiation (UVR) is predominant. Determine if two extracts of maca can provide dermal protection against UVR. We have administered two maca extracts (0.13 mg/ml), one obtained after boiling and the other without boiling, on the dorsal surface of male Holtzman rats exposed to UVC radiation once a week during 3 consecutive weeks. A dose-response effect of an aqueous extract of maca after a boiling process under exposure of rats to UVA, UVB, or UVC was also studied. A commercial sunscreen was used as a positive control. UVR caused significant increase in skin epidermal thickness. The epidermal height in animals treated with maca was similar to those who did not receive UVR. The aqueous extract of maca after a boiling process had better effect than maca extract without a boiling process. A dose-response effect was observed with increasing doses of aqueous extract of maca after a boiling process. Maca extract had benzyl glucosinolates and polyphenols. Maca extracts protect the skin of rats against UV irradiations and can be suggested as an alternative means of solar protection.

  11. Protective effect of polysaccharide from maca (Lepidium meyenii) on Hep-G2 cells and alcoholic liver oxidative injury in mice.

    Science.gov (United States)

    Zhang, Lijun; Zhao, Qingsheng; Wang, Liwei; Zhao, Mingxia; Zhao, Bing

    2017-06-01

    To study the characterization and hepatoprotective activity of polysaccharide from maca (Lepidium meyenii), the main polysaccharide from maca (MP-1) was obtained by DEAE-52 cellulose column. The average molecular weight of MP-1 was 1067.3kDa and the polysaccharide purity was 91.63%. In order to assess the antioxidant activities of MP-1, four kinds of methods were used, including scavenging hydroxyl radical, DPPH, superoxide anion radical, and FRAP, and the results indicated high antioxidant activities. Furthermore, hepatoprotective activity of MP-1 was studied both in vitro and vivo. In vitro, the alcohol induced Hep-G2 cells model was established to evaluate the protective effect of MP-1, which demonstrated MP-1 can alleviate alcohol damage in Hep-G2 cells. In vivo, the Institute of Cancer Researcch (ICR) mice were used to evaluate hepatoprotecive effects of MP-1 on alcoholic liver disease (ALD). Supplement with MP-1 supressed the triglyceride level both in serum and in hepatic tissue. In addition, MP-1 ameliorated serous transaminases increase induced by alcohol, including aspartate transaminase, alanine aminotransferase, and γ-glutamyl transpeptidase. Moreover, MP-1 also dramatically increased the superoxide dismutase, glutathione peroxidase, and glutathione s-transferase levels in alcoholic mice. Meantime, histopathologic results MP-1 lighten inflammation induced by alcohol. These results indicate that MP-1 possesses hepatoprotective activity against hepatic injury induced by alcohol. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Identification and characterization of microRNAs and their targets in high-altitude stress-adaptive plant maca (Lepidium meyenii Walp).

    Science.gov (United States)

    Paul, Sujay

    2017-06-01

    MicroRNAs (miRNAs) are endogenous, short (~21-nucleotide), non-coding RNA molecules that play pivotal roles in plant growth, development, and stress response signaling. In this study using recently published draft genome sequence of a high-altitude plant maca (Lepidium meyenii Walp) and applying genome-wide computational-based approaches, a total of 62 potentially conserved miRNAs belonging to 28 families were identified and four (lme-miR160a, lme-miR164c, lme-miR 166a, and lme-miR 319a) of them further validated by RT-PCR. Deploying psRNATarget tool a total of 99 potential miRNA target transcripts were also identified in maca. Targets include a number of transcription factors like Squamosa promoter-binding, NAC, MYB, auxin response factor, APETALA, WRKY, and F-box protein. To the best of my knowledge, this is the first genome-based miRNA profiling of a high-altitude plant.

  13. Long-term feeding of hydroalcoholic extract powder of Lepidium meyenii (maca) enhances the steroidogenic ability of Leydig cells to alleviate its decline with ageing in male rats.

    Science.gov (United States)

    Yoshida, K; Ohta, Y; Kawate, N; Takahashi, M; Inaba, T; Hatoya, S; Morii, H; Takahashi, K; Ito, M; Tamada, H

    2018-02-01

    This study examined whether feeding hydroalcoholic extract of Lepidium meyenii (maca) to 8-week-old (sexually maturing) or 18-week-old (mature) male rats for more than a half year affects serum testosterone concentration and testosterone production by Leydig cells cultured with hCG, 22R-hydroxycholesterol or pregnenolone. Testosterone concentration was determined in the serum samples obtained before and 6, 12, 18 and 24 weeks after the feeding, and it was significantly increased only at the 6 weeks in the group fed with the maca extract to maturing rats when it was compared with controls. Testosterone production by Leydig cells significantly increased when cultured with hCG by feeding the maca extract to maturing rats for 27 weeks (35 weeks of age) and when cultured with 22R-hydroxycholesterol by feeding it to mature rats for 30 weeks (48 weeks of age). Overall testosterone production by cultured Leydig cells decreased to about a half from 35 to 48 weeks of age. These results suggest that feeding the maca extract for a long time to male rats may enhance the steroidogenic ability of Leydig cells to alleviate its decline with ageing, whereas it may cause only a transient increase in blood testosterone concentration in sexually maturing male rats. © 2017 Blackwell Verlag GmbH.

  14. (+)-Meyeniins A-C, Novel Hexahydroimidazo[1,5-c]thiazole Derivatives from the Tubers of Lepidium meyenii: Complete Structural Elucidation by Biomimetic Synthesis and Racemic Crystallization.

    Science.gov (United States)

    Zhou, Min; Ma, Hang-Ying; Liu, Zhi-Hua; Yang, Guang-Yu; Du, Gang; Ye, Yan-Qing; Li, Gan-Peng; Hu, Qiu-Fen

    2017-03-08

    (+)-Meyeniins A-C (1-3), a novel class of sulfur-containing hexahydroimidazo[1,5-c]thiazole derivatives, were isolated from the tubers of Lepidium meyenii (maca) cultivated in Lijiang, Yunnan province, China. Guided by their biosynthetic hypothesis, a stereocontrolled biomimetic synthesis of meyeniins A-C and their individual enantiomers was efficiently accomplished by a combination of a condensation reaction and Edman degradation. The formation of high-quality crystals for X-ray crystallography occurred much more readily from a racemic mixture of (±)-meyeniin A than with the single enantiomer alone in this case. These extensive strategies, combined with circular dichroism (CD) spectra, allowed the complete structural assignments of (+)-meyeniins A-C. Among them, (+)-meyeniin A showed moderate selective cytotoxicities against the HL-60, A549 and MCF-7 human cell lines with IC 50 values of 14.41, 32.22, and 33.14 μM, respectively. To some extent, these findings support traditional applications of maca as healthy nutritional supplements or functional foods for cancer prevention.

  15. Aqueous extract of yellow maca (Lepidium meyenii) improves sperm count in experimental animals but response depends on hypocotyl size, pH and routes of administration.

    Science.gov (United States)

    Sanchez-Salazar, L; Gonzales, G F

    2018-04-01

    Lepidium meyenii, a Peruvian plant growing over 4000 m.a.s.l., has effects on nutrition and fertility. The purpose of this study was to evaluate the sperm count in 105 male mice receiving boiled aqueous extract of yellow maca hypocotyls from different sizes, under different pH conditions and using two different routes of administration. Five mice per group were treated daily for 3 days with vehicle (oral and intraperitoneal) or maca aqueous extracts (5 mg/0.5 ml/day) belonging to the first, second, third and fourth categories, according to their hypocotyl size. On day four, sperm count was evaluated at testis, epididymis and vas deferens. Sperm count was higher in mice receiving maca from the larger sizes (first and second categories). Reduction in maca extract pH increased sperm count, whereas an increase in the pH resulted in a reduction in sperm count. The effect of pH reduction is observed only in maca from the first and second categories. Aqueous extract of maca was effective only after oral administration. In conclusion, the larger size of hypocotyls presented the best biological effect, and the low pH in the extract and the transformation after gastrointestinal passage are both important for its biological action. © 2017 Blackwell Verlag GmbH.

  16. Subjective effects of Lepidium meyenii (Maca) extract on well-being and sexual performances in patients with mild erectile dysfunction: a randomised, double-blind clinical trial.

    Science.gov (United States)

    Zenico, T; Cicero, A F G; Valmorri, L; Mercuriali, M; Bercovich, E

    2009-04-01

    Lepidium meyenii (Maca) is a cultivated root belonging to the brassica family used in the Andean region for its supposed aphrodisiac properties. We carried out a double-blind clinical trial on 50 Caucasian men affected by mild erectile dysfunction (ED), randomised to treatment with Maca dry extract, 2400 mg, or placebo. The treatment effect on ED and subjective well-being was tested administrating before and after 12 weeks the International Index of Erectile Function (IIEF-5) and the Satisfaction Profile (SAT-P). After 12 weeks of treatment, both Maca- and placebo-treated patients experienced a significant increase in IIEF-5 score (P < 0.05 for both). However, patients taking Maca experienced a more significant increase than those taking placebo (1.6 +/- 1.1 versus 0.5 +/- 0.6, P < 0.001). Both Maca- and placebo-treated subjects experienced a significant improvement in psychological performance-related SAT-P score, but the Maca group higher than that of placebo group (+9 +/- 6 versus +6 +/- 5, P < 0.05). However, only Maca-treated patients experienced a significant improvement in physical and social performance-related SAT-P score compared with the baseline (+7 +/- 6 and +7 +/- 6, both P < 0.05). In conclusion, our data support a small but significant effect of Maca supplementation on subjective perception of general and sexual well-being in adult patients with mild ED.

  17. Effect of Lepidium meyenii Walp. on Semen Parameters and Serum Hormone Levels in Healthy Adult Men: A Double-Blind, Randomized, Placebo-Controlled Pilot Study.

    Science.gov (United States)

    Melnikovova, Ingrid; Fait, Tomas; Kolarova, Michaela; Fernandez, Eloy C; Milella, Luigi

    2015-01-01

    Background/Aims. Products of Lepidium meyenii Walp. (maca) are touted worldwide as an alimentary supplement to enhance fertility and restore hormonal balance. Enhancing properties of maca on semen parameters in animals were previously reported by various authors, but we present to the best of our knowledge the first double-blind, randomized, placebo-controlled pilot trial in men. The aim of this study was to evaluate the effects of maca on semen parameters and serum hormone levels in healthy adult men. Methods. A group of 20 volunteers aged 20-40 years was supplied by milled hypocotyl of maca or placebo (1.75 g/day) for 12 weeks. Negative controls of semen were compared to the samples after 6 and 12 weeks of maca administration; negative blood controls were compared to the samples after 12 weeks of treatment. Results. Sperm concentration and motility showed rising trends compared to placebo even though levels of hormones did not change significantly after 12 weeks of trial. Conclusion. Our results indicate that maca possesses fertility enhancing properties in men. As long as men prefer to use alimentary supplement to enhance fertility rather than prescribed medication or any medical intervention, it is worth continuing to assess its possible benefits.

  18. Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) increases serum testosterone concentration and enhances steroidogenic ability of Leydig cells in male rats.

    Science.gov (United States)

    Ohta, Y; Yoshida, K; Kamiya, S; Kawate, N; Takahashi, M; Inaba, T; Hatoya, S; Morii, H; Takahashi, K; Ito, M; Ogawa, H; Tamada, H

    2016-04-01

    Although Lepidium meyenii (maca), a plant growing in Peru's central Andes, has been traditionally used for enhancing fertility and reproductive performance in domestic animals and human beings, effects of maca on reproductive organs are still unclear. This study examined whether feeding the hydroalcoholic extract powder of maca for 6 weeks affects weight of the reproductive organs, serum concentrations of testosterone and luteinising hormone (LH), number and cytoplasmic area of immunohistochemically stained Leydig cells, and steroidogenesis of cultured Leydig cells in 8-week-old male rats. Feeding the extract powder increased weight of seminal vesicles, serum testosterone level and cytoplasmic area of Leydig cells when compared with controls. Weight of prostate gland, serum LH concentration and number of Leydig cells were not affected by the maca treatment. The testosterone production by Leydig cells significantly increased when cultured with 22R-hydroxycholesterol or pregnenolone and tended to increase when cultured with hCG by feeding the extract powder. The results show that feeding the hydroalcoholic extract powder of maca for 6 weeks increases serum testosterone concentration associated with seminal vesicle stimulation in male rats, and this increase in testosterone level may be related to the enhanced ability of testosterone production by Leydig cells especially in the metabolic process following cholesterol. © 2015 Blackwell Verlag GmbH.

  19. Structural, electronic, topological and vibrational properties of a series of N-benzylamides derived from Maca (Lepidium meyenii) combining spectroscopic studies with ONION calculations

    Science.gov (United States)

    Chain, Fernando E.; Ladetto, María Florencia; Grau, Alfredo; Catalán, César A. N.; Brandán, Silvia Antonia

    2016-02-01

    In the present work, the structural, topological and vibrational properties of four members of the N-benzylamides series derived from Maca (Lepidium meyenii) whose names are, N-benzylpentadecanamide, N-benzylhexadecanamide, N-benzylheptadecanamide and N-benzyloctadecanamide, were studied combining the FTIR, FT-Raman and 1H and 13C-NMR spectroscopies with density functional theory (DFT) and ONION calculations. Furthermore, the N-benzylacetamide, N-benzylpropilamide and N-benzyl hexanamide derivatives were also studied in order to compare their properties with those computed for the four macamides. These seven N-benzylamides series have a common structure, C8H8NO-R, being R the side chain [-(CH2)n-CH3] with a variable n number of CH2 groups. Here, the atomic charges, molecular electrostatic potentials, stabilization energies, topological properties of those macamides were analyzed as a function of the number of C atoms of the side chain while the frontier orbitals were used to compute the gap energies and some descriptors in order to predict their reactivities and behaviors in function of the longitude of the side chain. Here, the force fields, the complete vibrational assignments and the corresponding force constants were only reported for N-benzylacetamide, N-benzyl hexanamide and N-benzylpentadecanamide due to the high number of vibration normal modes that present the remains macamides.

  20. Structural Characterization of a Novel Polysaccharide from Lepidium meyenii (Maca) and Analysis of Its Regulatory Function in Macrophage Polarization in Vitro.

    Science.gov (United States)

    Zhang, Mengmeng; Wu, Wenjia; Ren, Yao; Li, Xiaofeng; Tang, Yuqian; Min, Tian; Lai, Furao; Wu, Hui

    2017-02-15

    In our previous study, three novel polysaccharides, named MC-1, MC-2, and MC-3, were separated from the roots of maca (Lepidium meyenii), which is a food source from the Andes region. The structural information and immunomodulatory activity of MC-1 were then investigated. The structure and activity of MC-2 are still unknown. In this study, structural characterization revealed that MC-2 has an average molecular weight of 9.83 kDa and is composed of arabinose (20.9%), mannose (4.5%), glucose (71.9%), and galactose (2.7%). The main linkage types of MC-2 were proven to be (1→5)-α-l-Ara, (1→3)-α-l-Man, (1→)-α-d-Glc, (1→4)-α-d-Glc, (1→6)-α-d-Glc, and (1→6)-β-d-Gal by methylation and NMR analyses. Congo red assay showed that MC-2 possesses a triple-helix conformation. Immunostimulating assays indicated that MC-2 could induce M1 polarization of original macrophages and convert M2 macrophages into M1 phenotype. Although MC-2 could not shift M1 macrophages into M2, it could still inhibit inflammatory reactions induced by lipopolysaccharide. Furthermore, Toll-like receptor 2, tTll-like receptor 4, complement receptor 3, and mannose receptor were confirmed as the membrane receptors for MC-2 on macrophages. These results indicate that MC-2 could potentially be used toward hypoimmunity and tumor therapies.

  1. Photoprotection against the UVB-induced oxidative stress and epidermal damage in mice using leaves of three different varieties of Lepidium meyenii (maca).

    Science.gov (United States)

    Gonzales-Castañeda, Cynthia; Rivera, Valery; Chirinos, Ana Lucía; Evelson, Pablo; Gonzales, Gustavo Francisco

    2011-08-01

    Skin exposure to ultraviolet (UV) B radiation leads to epidermal damage and generation of reactive oxygen species. The photoprotective effect of extracts of three varieties of leaves (red, yellow, and black) from maca (Lepidium meyenii), a plant from the Peruvian highlands, was assessed in mouse skin exposed to UVB radiation. The hydroalcoholic extracts of three varieties of maca leaves were applied topically to the dorsal skin of young-adult male mice prior to exposition to UVB radiation. The three varieties had UVA/UVB absorptive properties and presented antioxidant activity, being highest with red maca, followed by black and yellow maca. The three varieties of maca leaves prevented the development of sunburn cells, epidermal hyperplasia, leukocytic infiltration, and other alterations produced by UVB radiation. Mice treated with black maca showed the highest superoxide dismutase levels, and mice treated with black and yellow maca showed higher catalase levels in skin, whereas red maca protected the skin and liver against significant increases in the lipid peroxidation activity observed in the unprotected animals. The presence of significant antioxidant activity and the inhibition of lipid peroxidation suggest that the observed protection could be partly attributable to this mechanism. © 2011 The International Society of Dermatology.

  2. Effect of Lepidium meyenii Walp. on Semen Parameters and Serum Hormone Levels in Healthy Adult Men: A Double-Blind, Randomized, Placebo-Controlled Pilot Study

    Science.gov (United States)

    Melnikovova, Ingrid; Fait, Tomas; Kolarova, Michaela; Fernandez, Eloy C.

    2015-01-01

    Background/Aims. Products of Lepidium meyenii Walp. (maca) are touted worldwide as an alimentary supplement to enhance fertility and restore hormonal balance. Enhancing properties of maca on semen parameters in animals were previously reported by various authors, but we present to the best of our knowledge the first double-blind, randomized, placebo-controlled pilot trial in men. The aim of this study was to evaluate the effects of maca on semen parameters and serum hormone levels in healthy adult men. Methods. A group of 20 volunteers aged 20–40 years was supplied by milled hypocotyl of maca or placebo (1.75 g/day) for 12 weeks. Negative controls of semen were compared to the samples after 6 and 12 weeks of maca administration; negative blood controls were compared to the samples after 12 weeks of treatment. Results. Sperm concentration and motility showed rising trends compared to placebo even though levels of hormones did not change significantly after 12 weeks of trial. Conclusion. Our results indicate that maca possesses fertility enhancing properties in men. As long as men prefer to use alimentary supplement to enhance fertility rather than prescribed medication or any medical intervention, it is worth continuing to assess its possible benefits. PMID:26421049

  3. Prevalencia de hongos en harina de Lepidium peruvianum «Maca» en mercados de Andahuaylas, Ica y Cañete - Perú

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    Alfonso Orellana

    2013-05-01

    Full Text Available Se determinó la prevalencia de hongos en la harina de Lepidium peruvianum «maca» en un total de 60 muestras procedentes de los mercados de Andahuaylas (20, Ica (20 y Cañete (20. Las muestras fueron procesadas mediante el método de diluciones sucesivas y sembradas en superficie en Agar Papa Dextrosa (APD. El 96,7% del total de muestras estaban contaminadas; identificándose 9 géneros y un total de 14 especies de mohos filamentosos, incluyendo uno clasificado como Mycelia sterilia. El recuento general de colonias va desde 33x104 a 61x104 UFC/g., no existiendo diferencia significativa entre los centros de expendio. Los géneros con mayor incidencia fueron Penicillium y Fusarium. La alta prevalencia de hongos contaminantes en la harina de maca sugieren continuar estudios destinados a evaluar el efecto y riesgo sanitario que representa su consumo para la salud humana.

  4. Effect of Lepidium meyenii Walp. on Semen Parameters and Serum Hormone Levels in Healthy Adult Men: A Double-Blind, Randomized, Placebo-Controlled Pilot Study

    Directory of Open Access Journals (Sweden)

    Ingrid Melnikovova

    2015-01-01

    Full Text Available Background/Aims. Products of Lepidium meyenii Walp. (maca are touted worldwide as an alimentary supplement to enhance fertility and restore hormonal balance. Enhancing properties of maca on semen parameters in animals were previously reported by various authors, but we present to the best of our knowledge the first double-blind, randomized, placebo-controlled pilot trial in men. The aim of this study was to evaluate the effects of maca on semen parameters and serum hormone levels in healthy adult men. Methods. A group of 20 volunteers aged 20–40 years was supplied by milled hypocotyl of maca or placebo (1.75 g/day for 12 weeks. Negative controls of semen were compared to the samples after 6 and 12 weeks of maca administration; negative blood controls were compared to the samples after 12 weeks of treatment. Results. Sperm concentration and motility showed rising trends compared to placebo even though levels of hormones did not change significantly after 12 weeks of trial. Conclusion. Our results indicate that maca possesses fertility enhancing properties in men. As long as men prefer to use alimentary supplement to enhance fertility rather than prescribed medication or any medical intervention, it is worth continuing to assess its possible benefits.

  5. Bioactivity of Dianthus caryophyllus, Lepidium sativum, Pimpinella anisum, and Illicium verum essential oils and their major components against the West Nile vector Culex pipiens.

    Science.gov (United States)

    Kimbaris, Athanasios C; Koliopoulos, George; Michaelakis, Antonios; Konstantopoulou, Maria A

    2012-12-01

    Mosquitoes constitute a severe health problem in many areas all over the world. There are many regions of the tropics and subtropics where mosquitoes are one of the main reasons for inhibiting the economic upgrade. Except nuisance, their medical importance is another matter of attention since mosquitoes are vectors for a wide variety of vector-borne diseases. Due to disadvantages of currently used chemical control methods, it is unavoidable to search for eco-friendly new molecules. We report herein the evaluation of the larvicidal effect exhibited by essential oils of Dianthus caryophyllus, Lepidium sativum, Pimpinella anisum, and Illicium verum against late third to early fourth instar mosquito larvae of Culex pipiens. Furthermore, phytochemical analysis of plant samples revealed their major compounds to be β-caryophyllene, eugenol, eucalyptol, α-terpinyl acetate, and (E)-anethole which were also tested for their potential larvicidal activity. For D. caryophyllus and L. sativum, this was the first report on the chemical composition of their essential oils. The essential oils of I. verum and P. anisum demonstrated high larvicidal activity with a LC(50) <18 mg L(-1). The other two essential oils of D. caryophyllus and L. sativum revealed moderate larvicidal activity, displaying a LC(50) value above 50 mg L(-1). Among the pure components, the most toxic were eugenol, (E)-anethole, and α-terpinyl acetate, with LC(50) values 18.28, 16.56, and 23.03 mg L(-1), respectively. Eucalyptol (1,8 cineole) and β-caryophyllene were inactive at concentrations even as high as 100 mg L(-1), showing the least significant activity against mosquito larvae. Results allow some rationalization on the relative importance of the major compounds regarding the larvicidal activity of selected essential oils and their potential use as vector control agents.

  6. The Influence of pH of Extracting Water on the Composition of Seaweed Extracts and Their Beneficial Properties onLepidium sativum.

    Science.gov (United States)

    Godlewska, Katarzyna; Michalak, Izabela; Tuhy, Łukasz; Chojnacka, Katarzyna

    2017-01-01

    Baltic seaweeds were used to obtain aqueous extracts (E) through changing initial pH of deionised water added to algal biomass (EpH3·H 2 O, EpH7·H 2 O, and EpH10·H 2 O) and through changing pH of the mixture of algae and deionised water (EpH3, EpH7, and EpH10). Algal extracts were characterized in terms of the concentration of polyphenols and micro- and macroelements. The highest concentration of polyphenols was determined in extract EpH3 and the lowest in extract EpH10·H 2 O. It was found that the obtained extracts had similar concentrations of elements (except EpH3). The phytotoxicity of algal extracts (0.5, 2.5, and 10%) was examined in the germination tests on Lepidium sativum . No phytotoxic effects were observed. It was found that they had beneficial effects on the cultivated plants (length and weight). The best biostimulant effect was observed in the groups treated with EpH3 (2.5%), EpH7 (2.5%), and EpH7 (10%). The dry weight of plants was similar in all the groups. Algal extract also improved the multielemental composition of plant. The greatest concentration of total chlorophyll in plants was obtained by using extract EpH10·H 2 O, 0.5%. These results proved that algal extracts have high potential to be applied in cultivation of plants.

  7. Efecto bifidogénico de jalea de Lepidium meyenii Walp. “maca” en el recuento de Bifidobacterium bifidum en yogurt probiótico

    Directory of Open Access Journals (Sweden)

    María Elena León Marroú

    2011-01-01

    Full Text Available Los recuentos de Bifidobacterium bifidum en yogures probióticos tienden a disminuir de manera significativa por diferentes factores: pH, oxígeno disuelto, composición antagónica entre las especies, la composición química del medio, temperatura de almacenamiento, entre otros. Para asegurar que la eficacia de los productos que contienen B. bifidum sea máxima a menudo se incluyen factores bifidogénicos, los cuales tienen la propiedad de promover no solo el crecimiento adecuado, sino también su viabilidad durante el almacenamiento del producto final. El presente estudio investigó sobre el recuento de B. bifidum en yogurt probiótico elaborado en condiciones de laboratorio en relación a dos variables: adición de tres concentraciones diferentes de jalea de Lepidium meyenii “maca” (10 %, 20 % y 30 % y tiempo de almacenamiento. Se realizó el recuento de B. bifidum cada tres días, durante un mes. Se utilizó el método de recuento en placa por siembra en profundidad. Los resultados indicaron que todas las muestras a las que se añadieron jalea de L. meyenii “maca” en diferentes concentraciones mantuvieron recuentos de B. bifidum por encima de los valores establecidos por las normas internacionales. Se concluye que L. meyenii “maca”, en razón de algunos de sus componentes, ejerció un efecto bifidogénico y en concentración de 30 % de jalea fue mayor.

  8. Efecto bifidogénico de jalea de Lepidium meyenii Walp. “maca” en el recuento de Bifidobacterium bifidum en yogurt probiótico

    Directory of Open Access Journals (Sweden)

    María Elena León Marroú

    2011-06-01

    Full Text Available Los recuentos de Bifidobacterium bifidum en yogures probióticos tienden a disminuir de manera significativa por diferentes factores: pH, oxígeno disuelto, composición antagónica entre las especies, la composición química del medio, temperatura de almacenamiento, entre otros. Para asegurar que la eficacia de los productos que contienen B. bifidum sea máxima a menudo se incluyen factores bifidogénicos, los cuales tienen la propiedad de promover no solo el crecimiento adecuado, sino también su viabilidad durante el almacenamiento del producto final. El presente estudio investigó sobre el recuento de B. bifidum en yogurt probiótico elaborado en condiciones de laboratorio en relación a dos variables: adición de tres concentraciones diferentes de jalea de Lepidium meyenii “maca” (10 %, 20 % y 30 % y tiempo de almacenamiento. Se realizó el recuento de B. bifidum cada tres días, durante un mes. Se utilizó el método de recuento en placa por siembra en profundidad. Los resultados indicaron que todas las muestras a las que se añadieron jalea de L. meyenii “maca” en diferentes concentraciones mantuvieron recuentos de B. bifidum por encima de los valores establecidos por las normas internacionales. Se concluye que L. meyenii “maca”, en razón de algunos de sus componentes, ejerció un efecto bifidogénico y en concentración de 30 % de jalea fue mayor.

  9. Effect of short-term and long-term treatments with three ecotypes of Lepidium meyenii (MACA) on spermatogenesis in rats.

    Science.gov (United States)

    Gonzales, Carla; Rubio, Julio; Gasco, Manuel; Nieto, Jessica; Yucra, Sandra; Gonzales, Gustavo F

    2006-02-20

    Lepidium meyenii (Brassicaceae), known as Maca, is a Peruvian hypocotyl that grows exclusively between 4000 and 4500 m above sea level in the central Andes. Maca is traditionally employed in the Andean region for its supposed fertility-enhancing properties. The study aimed to test the hypothesis that different ecotypes of Maca (Red, Yellow and Black) after short-term (7 days) and long-term (42 days) treatment affects differentially spermatogenesis adult rats. After 7 days of treatment with Yellow and Red Maca, the length of stage VIII was increased (P<0.05), whereas with Black Maca stages II-VI and VIII were increased (P<0.05). Daily sperm production (DSP) was increased in the group treated with Black Maca compared with control values (P<0.05). Red or Yellow Maca did not alter DSP and epididymal sperm motility was not affected by treatment with any ecotype of Maca. After 42 days of treatment, Black Maca was the only ecotype that enhanced DSP (P<0.05). Moreover, Black Maca was the only that increased epididymal sperm motility (P<0.05). In relation to the control group, Red Maca did not affect testicular and epididymal weight nor epididymal sperm motility and sperm count; however, prostate weight was reduced (P<0.05). Black or Yellow Maca did not affect prostate weight. In conclusion, there were differences in the biological response of the three ecotypes of Maca (Yellow, Red and Black). Black Maca appeared to have more beneficial effect on sperm counts and epididymal sperm motility.

  10. Effect of gamma irradiation on phenol content, antioxidant activity and biological activity of black maca and red maca extracts (Lepidium meyenii walp).

    Science.gov (United States)

    Zevallos-Concha, A; Nuñez, D; Gasco, M; Vasquez, C; Quispe, M; Gonzales, G F

    2016-01-01

    This study was performed to determine the effects of gamma irradiation on UV spectrum on maca, total content of polyphenols, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities and in vivo biological activities of red and black maca extracts (Lepidium meyenii). Adult mice of the strain Swiss aged 3 months and weighing 30-35 g in average were used to determine biological activities. Daily sperm production, effect on testosterone-induced prostate hyperplasia and forced swimming test were used to determine the effect of irradiation on biological activities of maca extracts. Irradiation did not show differences in UV spectrum but improves the amount of total polyphenols in red maca as well as in black maca extracts. In both cases, black maca extract has more content of polyphenols than red maca extract (p  0.05). Black maca extract but not red maca extract has more swimming endurance capacity in the forced swimming test. Irradiation of black maca extract increased the swimming time to exhaustion (p  0.05). Testosterone enanthate (TE) increased significantly the ventral prostate weight. Administration of red maca extract in animals treated with TE prevented the increase in prostate weight. Irradiation did not modify effect of red maca extract on prostate weight (p > 0.05). In conclusion, irradiation does not alter the biological activities of both black maca and red maca extracts. It prevents the presence of microorganisms in the extracts of black or red maca, but the biological activities were maintained.

  11. Peruvian Maca (Lepidium peruvianum) - III: The Effects of Cultivation Altitude on Phytochemical and Genetic Differences in the Four Prime Maca Phenotypes.

    Science.gov (United States)

    Meissner, Henry O; Mscisz, Alina; Baraniak, Marek; Piatkowska, Ewa; Pisulewski, Pawel; Mrozikiewicz, Mieczyslaw; Bobkiewicz-Kozlowska, Teresa

    2017-06-01

    In two trials, dietary and Glucosinolates' characteristics in four Maca phenotypes have been examined with an extension into the determination of DNA sequences. Hypocotyls of the four prime phenotypes of Peruvian Maca - Lepidium peruvianum Chacon, labelled as "Yellow", "Black", "Red" and "Purple" were separated from mixed Maca crops cultivated in four geographically-distant locations in the Peruvian Andes at altitudes between 2,800m and 4,300 m a.s.l. It was found that at higher altitudes where Red and Purple Maca phenotypes were grown, the significantly higher ( P Maca physiological activity, were observed with the Purple phenotype showing the highest Glucosinolates' content at 4,300m a.s.l., followed by the Red-coloured hypocotyls. Black Maca showed a reversal, but also a significant ( P 0.05) and has consistently the lowest Glucosinolates content. Thus, it is reasonable to assume that the altitude at which Red, Purple and Black phenotypes of L. peruvianum are grown, may be responsible for the variation in physiologic functionalities, leading to different than expected specific therapeutic and health benefits induced by Maca phenotypes grown at diverse altitudes. Although promising, insufficiently precise differences in DNA sequences failed to distinguish, without any reasonable doubt, four Maca phenotypes cultivated either in the same or geographically-distant locations, and harvested at different altitudes a.s.l. Further research on DNA sequences is needed, with more primers and larger number of Maca phenotypes, considering biosynthesis of secondary metabolites and adaptation pathways induced by harsh environment at altitudes where Maca is cultivated.

  12. Hormone-Balancing Effect of Pre-Gelatinized Organic Maca (Lepidium peruvianum Chacon): (I) Biochemical and Pharmacodynamic Study on Maca using Clinical Laboratory Model on Ovariectomized Rats.

    Science.gov (United States)

    Meissner, H O; Mrozikiewicz, P; Bobkiewicz-Kozlowska, T; Mscisz, A; Kedzia, B; Lowicka, A; Reich-Bilinska, H; Kapczynski, W; Barchia, I

    2006-09-01

    Ovariectomized rats were used in a model laboratory study to examine biochemical and pharmacodynamic effects of pre-gelatinized organic preparation of Lepidium peruvianum Chacon (Maca-GO). Biochemical and Pharmacodynamic effects of Maca-GO (250 mg Maca-GO per kg body weight (bw) administered by intubation twice daily) were assessed in a 28 day model laboratory study on ovariectomized (by laparoscopy) Wistar rats with pharmacodynamic tests performed at the conclusion of the trial followed by blood collection for morphology and biochemical tests. Toxicity of Maca-GO used in the study was determined in bioassay on mice and rats. Anti-depressive function (Porsolt's test) and anxiolytic sedative and cognitive effects (using elevated-plus maze, locomotor activity and passive avoidance tests) were assessed against control (laparotomized female rats with intact ovaries). In addition to blood morphology, the following blood serum constituents were analyzed: Estrogen (E2), Progesterone (PGS), Cortisol (CT), Adrenocorticotropic Hormone (ACTH), Thyroid Hormones (TSH, T3, and T4), Iron (Fe) and lipid profile (Triglycerides, Total Cholesterol, LDL, HDL). Analytically-determined non-toxic status of Maca-GO was confirmed in bioassays when applied to mice and rats at levels of 0.5 and up to 15mg/kg bw which shows it safe use in humans with the LD50>15 mg/kg bw. Maca-GO showed a distinctive, (PMaca-GO on sex hormone levels show its potential as a safe preparation for use in correcting physiological symptoms characteristic in postmenopausal stage with an indication of potentially even more value for its use in pre-menopausal women.

  13. Peruvian Maca (Lepidium peruvianum) – III: The Effects of Cultivation Altitude on Phytochemical and Genetic Differences in the Four Prime Maca Phenotypes

    Science.gov (United States)

    Meissner, Henry O.; Mscisz, Alina; Baraniak, Marek; Piatkowska, Ewa; Pisulewski, Pawel; Mrozikiewicz, Mieczyslaw; Bobkiewicz-Kozlowska, Teresa

    2017-01-01

    In two trials, dietary and Glucosinolates’ characteristics in four Maca phenotypes have been examined with an extension into the determination of DNA sequences. Hypocotyls of the four prime phenotypes of Peruvian Maca - Lepidium peruvianum Chacon, labelled as “Yellow”, “Black”, “Red” and “Purple” were separated from mixed Maca crops cultivated in four geographically-distant locations in the Peruvian Andes at altitudes between 2,800m and 4,300 m a.s.l. It was found that at higher altitudes where Red and Purple Maca phenotypes were grown, the significantly higher (PMaca physiological activity, were observed with the Purple phenotype showing the highest Glucosinolates’ content at 4,300m a.s.l., followed by the Red-coloured hypocotyls. Black Maca showed a reversal, but also a significant (P0.05) and has consistently the lowest Glucosinolates content. Thus, it is reasonable to assume that the altitude at which Red, Purple and Black phenotypes of L. peruvianum are grown, may be responsible for the variation in physiologic functionalities, leading to different than expected specific therapeutic and health benefits induced by Maca phenotypes grown at diverse altitudes. Although promising, insufficiently precise differences in DNA sequences failed to distinguish, without any reasonable doubt, four Maca phenotypes cultivated either in the same or geographically-distant locations, and harvested at different altitudes a.s.l. Further research on DNA sequences is needed, with more primers and larger number of Maca phenotypes, considering biosynthesis of secondary metabolites and adaptation pathways induced by harsh environment at altitudes where Maca is cultivated. PMID:28824342

  14. The Influence of pH of Extracting Water on the Composition of Seaweed Extracts and Their Beneficial Properties on Lepidium sativum

    Directory of Open Access Journals (Sweden)

    Katarzyna Godlewska

    2017-01-01

    Full Text Available Baltic seaweeds were used to obtain aqueous extracts (E through changing initial pH of deionised water added to algal biomass (EpH3·H2O, EpH7·H2O, and EpH10·H2O and through changing pH of the mixture of algae and deionised water (EpH3, EpH7, and EpH10. Algal extracts were characterized in terms of the concentration of polyphenols and micro- and macroelements. The highest concentration of polyphenols was determined in extract EpH3 and the lowest in extract EpH10·H2O. It was found that the obtained extracts had similar concentrations of elements (except EpH3. The phytotoxicity of algal extracts (0.5, 2.5, and 10% was examined in the germination tests on Lepidium sativum. No phytotoxic effects were observed. It was found that they had beneficial effects on the cultivated plants (length and weight. The best biostimulant effect was observed in the groups treated with EpH3 (2.5%, EpH7 (2.5%, and EpH7 (10%. The dry weight of plants was similar in all the groups. Algal extract also improved the multielemental composition of plant. The greatest concentration of total chlorophyll in plants was obtained by using extract EpH10·H2O, 0.5%. These results proved that algal extracts have high potential to be applied in cultivation of plants.

  15. Extracto acuoso de Lepidium meyenii Walp (maca y su papel como adaptógeno, en un modelo animal de resistencia física

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    Silvia Suárez

    2009-09-01

    Full Text Available Introducción: El Lepidium meyenii Walp (maca es una raíz andina del Perú, utilizada como alimento por su valor nutricional y propiedades etnomedicinales; es parte de la medicina tradicional. Objetivos: Evaluar el papel de adaptógeno del extracto acuoso de maca amarilla sobre las enzimas del tejido muscular en un modelo animal de resistencia física y estrés oxidativo. Diseño: Experimental. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM, Lima, Perú. Material biológico: Extracto acuoso de la maca amarilla y ratas macho recién destetados. Intervenciones: Administración del extracto acuoso de la maca amarilla en ratas macho recién destetados, distribuidos en cuatro grupos: (I, de control, (II 0,4 mg de maca/g de peso (III 0,8 mg de maca/g de peso y (IV, 1,2 mg de maca/g de peso. El extracto acuoso fue administrado por cánula orogástrica. Se realizó un control de los pesos. Se aplicó la prueba de nado forzado después de 30 días de tratamiento. Los animales fueron sacrificados y se preparó homogenizado de músculo al 10%. Principales medidas de resultados: Actividad de las enzimas superóxido dismutasa (SOD, catalasa (CAT y lactato deshidrogenasa (LDH; y, como indicador de proceso oxidativo, se midió la peroxidación lipídica (TBARS. Resultados: El rendimiento en la prueba de resistencia fue la siguiente: (I 7,09 min; (II 11,25 min; (III 11,27 min; (IV 12,71 min, respectivamente. Las actividades enzimáticas de los grupos I, II, III y IV fueron: SOD (U/mL 36,6, 18,2, 17,2 y 18,2; CAT (U/L 18,6, 16,5, 13,4 y 10,3; y LDH (U/mL 11,6, 6,5, 6,0 y 5,8. TBARS (umol/g tejido: 5,82, 7,15, 4,11 y 4,06. Conclusiones: La administración del extracto acuoso de maca amarilla favorece la respuesta del organismo a una situación estresante y físicamente extenuante, lo que correspondería al papel de un adaptógeno.

  16. Dose-response effects of Lepidium meyenii (Maca) aqueous extract on testicular function and weight of different organs in adult rats.

    Science.gov (United States)

    Chung, Francisco; Rubio, Julio; Gonzales, Carla; Gasco, Manuel; Gonzales, Gustavo F

    2005-04-08

    Lepidium meyenii (Brassicaceae) known as Maca grows exclusively between 4000 and 4500 m over the sea level in the Peruvian central Andes. The dried hypocotyls of Maca are traditionally used as food and for its supposed fertility-enhancing properties. A dose-response study was performed to determine the effect of 7 days oral administration of an aqueous lyophilized extract of Maca at 0.01-5 g/kg (corresponding to 0.022-11 g dry hypocotyls of Maca/kg) on body and different organ weights, stages of the seminiferous tubules, epididymal sperm count and motility, and serum testosterone and estradiol levels in rats. In doses up to 5 g extract/kg, no toxicity was observed. Almost all organ weights were similar in controls and in the Maca extract-treated groups. Seminal vesicles weight was significantly reduced at 0.01 and 0.10 g extract/kg. Maca increased in length of stages VII-VIII of the seminiferous tubules in a dose-response fashion, with highest response at 1.0 g/kg, while caput/corpus epididymal sperm count increased at the 1.0 g dose. Cauda epididymal sperm count, sperm motility, and serum estradiol level were not affected at any of the doses studied. Serum testosterone was lower at 0.10 g extract/kg. Low-seminal vesicle weights correlated with low-serum testosterone levels (R2=0.33; P<0.0001) and low-testosterone/estradiol ratio (R2=0.35; P<0.0001). Increase in epididymal sperm count was related to lengths of stages VII-VIII. Highest effect on stages VII-VIII of the seminiferous tubules was observed at 1.0 g Maca aqueous extract/kg. The present study demonstrated that Maca extract in doses up to 5 g/kg (equivalent to the intake of 770 g hypocotyls in a man of 70 kg) was safe and that higher effect on reproductive parameters was elicited with a dose of 1 g extract/kg corresponding to 2.2 g dry Maca hypocotyls/kg.

  17. Influences of dietary supplementation with Lepidium meyenii (Maca) on stallion sperm production and on preservation of sperm quality during storage at 5 °C.

    Science.gov (United States)

    Del Prete, C; Tafuri, S; Ciani, F; Pasolini, M P; Ciotola, F; Albarella, S; Carotenuto, D; Peretti, V; Cocchia, N

    2018-03-01

    Stallion semen is damaged by oxidative stress during cooling and transport. Semen processing and extenders have been tested to improve the fertilizing capacity of semen and to preserve semen during transport. Dietary supplementation with natural antioxidants has been proposed to prevent oxidative damages. In this study, for the first time, the effect of dietary supplementation with Lepidium meyenii (Maca) on the characteristics of fresh and chilled stallion semen was evaluated. Maca is a traditional Andean crop used as a nutraceutical for the fertility-enhancing properties that are linked with antioxidant activity. The diet of five stallions was supplemented with 20 g of Maca powder daily for a total of 60 days. A control group of five stallions received the same diet without Maca. Semen was collected once before the administration of Maca (D0), twice during the administration at 30 and 60 days (D30 and D60), and finally twice at 30 and 60 days after the end of the administration (D90 and D120). Ejaculates were processed for cooled shipping at 5 °C and evaluated in the laboratory for total and progressive motility, acrosome integrity, and lipid peroxidation after collection and after 24, 48, and 72 h of storage. Dietary supplementation with Maca improved sperm concentration (from 213 ± 80.4 to 447 ± 73.1 × 10 6 spz/mL) and total sperm count (from 10,880 ± 4377 to 24,783 ± 4419 × 10 6 spz). The beneficial effects of Maca supplementation on motility and acrosome integrity in the raw semen were detected from the end of treatment with Maca (D60) until the end of the study (D120). Furthermore, during cooling storage, total motility, progressive motility, and acrosome integrity declined more slowly in the Maca-treated group than in the control group. Lipid peroxidation did not change during cooling storage in either group and did not show a significant difference between the two groups. In this study, the dietary supplementation with Maca

  18. Short and long-term physiological responses of male and female rats to two dietary levels of pre-gelatinized maca (lepidium peruvianum chacon).

    Science.gov (United States)

    Meissner, H O; Kedzia, B; Mrozikiewicz, P M; Mscisz, A

    2006-02-01

    The aim of this study is to identify physiological responses of male and female rats to either a short- or long-term administration of two doses of Maca (Lepidium peruvianum) and observe relationships which may exist between groups of hormones and effects mediated by them. The effect of pre-gelatinized (extruded) organic Maca powder (Maca-GO) was studied on Sprague-Dowley male and female rats (1:1 ratio) receiving two dietary levels of Maca-GO (0.75 g/kg and 7.5 g/kg body weight) and assessed against control during 28 and 90 day laboratory trials on 30 and 60 rats respectively. Blood morphology, biochemistry (hormones, lipids and minerals) and histology of internal organs were determined. Homogenates of skeletal muscles and bones of rats were also analyzed. Maca-GO has low toxicity (LD=7.5 g/kg) and appears to be safe for short-term and extended use as dietary supplement or as a component of functional dietary and therapeutic preparations. There were different responses of male and female rats to different levels of Maca-GO administered during a short- and a longer-term periodl. When administered at higher dose for extended period of time (90 days), Maca-GO acted as a toner of hormonal processes in adult female rats at increased progesterone and a steady estradiol level, without affecting levels of blood FSH, LH and TSH. Obtained results justify further clinical research on use of Maca-GO in sportsmen, physically-active people of both sexes and peri-menopausal women to clarify mechanisms underlaying physiological mode of action of Maca-GO validaet in clinical study on humans. Substantial decrease in blood cortisol levels in a short- and longer-term trial and simultaneous tendency to lower blood ACTH, may indicate antidepressive effect of Maca-GO, which together with reduction in body weight, lowering triglycerides in blood plasma and increasing calcium and phosphorus deposition in bone and muscle tissues is worthy consideration in potential application to women at

  19. Disminución del daño oxidativo y efecto hipoglicemiante de la maca (Lepidium meyenii Walp en ratas con diabetes inducida por streptozotocina

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    María Elena Rodrigo

    2011-01-01

    Full Text Available Introducción: La maca es consumida desde tiempos ancestrales como parte de la dieta. Se le ha atribuido propiedades medicinales y se encuentra incluida en la medicina tradicional peruana. Estudios recientes describen que la admistración de maca reduce la glicemia en animales normoglicémicos, pero los mecanismos involucrados no están muy claros. Objetivos: Determinar el efecto hipoglicemiante y antioxidante de la harina de maca (Lepidium meyenii Walp del ecotipo amarillo, en ratas con diabetes inducida por estreptozotocina. Diseño: Experimental. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Harina de maca amarilla y ratas albinas Holtzmann machos con diabetes inducida. Intervenciones: Se administró la harina de maca amarilla a las ratas distribuidas en 4 grupos: grupo I control (solo dieta; II, harina de maca 4 g/día; III, harina de maca 6 g/día; y IV, dieta + glibenclamida 10 mg/kg de peso; el experimento duró 46 días. Se evaluó diariamente la glicemia y el peso; al final del experimento se determinó en sangre los niveles de insulina, parámetros de daño oxidativo (vitamina C y se midió la peroxidación lipídica (TBARS, como indicador del proceso oxidativo. Principales medidas de los resultados: Modificación de los niveles de glicemia, insulina, vitamina C y formación del complejo MDA-TBARS. Resultados: La administración de harina de maca en la dieta (4 a 6 g/día de animales diabéticos redujo la glicemia en 50%, incrementó los niveles de insulina 22% y mejoró los niveles de vitamina C respecto al grupo control. La administración de maca 4 g/día disminuyó el daño oxidativo, pues redujo la formación del complejo MDA-TBARS en 54% con respecto al grupo control. Conclusiones: La administración de harina de maca amarilla a animales diabéticos mejoró el metabolismo de la glucosa, regulando la glicemia y

  20. Relación de glutatión reducido/oxidado (GSH/GSSG en ratas diabéticas tratadas con maca (Lepidium meyenii walp

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    Ruth Cisneros

    2011-04-01

    Full Text Available Introducción: La diabetes mellitus y sus complicaciones representan un problema de salud pública. La hiperglucemia desencadena efectos bioquímicos dañinos para el organismo, como el estrés oxidativo y el proceso inflamatorio crónico, por lo que el uso de plantas medicinales con elevada capacidad antioxidante, como Lepidium meyenii Walp (maca, es una alternativa en el tratamiento de esta patología. Objetivo: Determinar si la ingestión de harina de maca mejora la relación glutatión reducido/oxidado (GSH/GSSG en ratas diabéticas. Diseño: Experimental. Institución: Centro de Investigación de Bioquímica y Nutrición, Facultad de Medicina, UNMSM, Lima, Perú. Material biológico: Harina de maca amarilla y ratas albinas Holtzman machos adultas. Intervenciones: Se utilizó 24 ratas, a los cuales se les indujo la diabetes con estreptozotocina (STZ 40 mg/kg de masa corporal y que fueron distribuidas aleatoriamente en cuatro grupos, de seis animales cada uno: control (CO, glibenclamida (GL 10 mg/kg de masa corporal, maca 4 g/día (M4 y maca 6 g/día (M6; el experimento duró 40 días. Se evaluó la glicemia, masa corporal y, al final del experimento, se determinó los niveles de GSH y GSSG en plasma y homogenizado de hígado. Principales medidas de resultados: Masa corporal, glicemia, GSH y GSSG en plasma y homogenizado de hígado. Resultados: A nivel plasmático, el glutatión circulante estuvo favorecido para la forma reducida. Los valores de la relación GSH/GSSG en los grupos tratados con maca estuvieron alrededor de 190, significativamente mayor al grupo CO. Conclusiones: La administración de harina de maca amarilla a ratas diabéticas incrementó la relación GSH/GSSG a nivel plasmático, contribuyendo a mejorar su estado redox.

  1. Biomimetic Synthesis of Macahydantoins A and B from Lepidium meyenii, and Structure Revision of Macahydantoin B as a Class of Thiohydantoin with a 4-Methyl-hexahydropyrrolo[1,2-c]imidazole Skeleton.

    Science.gov (United States)

    Zhou, Min; Ma, Hang-Ying; Xing, Huan-Huan; Li, Ping; Li, Gan-Peng; Geng, Hui-Chun; Hu, Qiu-Fen; Yang, Guang-Yu

    2017-09-15

    Phytochemical investigation on Lepidium meyenii led to the discovery of macahydantoin C (3), a new thiohydantoin with a 1,3-diazabicyclo[3.3.1]nonane core, the spectral properties of which indicate a potential structural misassignment of its previously reported analogue, macahydantoin B (2a). To probe this hypothesis, a concise, scalable, and biomimetic synthesis of the originally proposed 2a and its revised structure (2b) was efficiently accomplished using the modified Edman degradation as the key step from commercially available materials in 65% (three steps) and 52% (three steps) overall yields, respectively. These synthetic endeavors undoubtedly reassigned the structure of macahydantoin B as an unreported type of thiohydantoin featuring a 4-methyl-hexahydropyrrolo[1,2-c]imidazole scaffold.

  2. Efecto citotóxico del extracto metanólico de tres ecotipos de Lepidium peruvianum Chacón sobre líneas celulares HeLa y HT-29

    Directory of Open Access Journals (Sweden)

    Libertad Alzamora

    2013-05-01

    Full Text Available La búsqueda de compuestos naturales con actividad citotóxica y antitumoral es una de las prioridades actuales de la lucha contra el cáncer; motivo por el cual el objetivo del presente trabajo fue evaluar la actividad citotóxica de los extractos metanólicos (EM de los ecotipos negro, morado y amarillo de Lepidium peruvianum, Chacón (conocida también como Lepidium meyenii Walp. (maca sobre las líneas celulares HeLa (Human Epithelial Carcinoma y HT-29 (Human Colon Adenocarcinoma. Se determinó que la concentración inhibitoria del 50% del crecimiento celular (IC50 para la línea celular HT-29, con los ecotipos negro, morado y amarillo fue de 8,32 mg/ml, 9,28 mg/ml y 0,487 mg/ml respectivamente, mientras que para la línea celular HeLa fue de 2,4 mg/ml, 1,93 mg/ml y 0,66 mg/ml respectivamente. Adicionalmente, se evaluó un EM del ecotipo amarillo con dos años de almacenamiento (10 ºC determinándose como IC50 4,29 mg/ml para HT-29 y 4,17 mg/ml para HeLa. Se concluye que el efecto citotóxico del ecotipo amarillo sobre HT-29 y HeLa fue superior al mostrado por los ecotipos negro y morado; que la línea celular más sensible a los ecotipos amarillo, negro y morado es HeLa, y que el EM del ecotipo amarillo conservó sus propiedades citotóxicas pese al tiempo de almacenamiento, aunque éstas disminuyeron.

  3. Therapeutic Effects of Pre-Gelatinized Maca (Lepidium Peruvianum Chacon) used as a Non-Hormonal Alternative to HRT in Perimenopausal Women - Clinical Pilot Study.

    Science.gov (United States)

    Meissner, H O; Reich-Bilinska, H; Mscisz, A; Kedzia, B

    2006-06-01

    Roots of cruciferous plant Lepidium peruvianum Chacon cultivated in high plateaus of Andes and known under its common name Maca, have been traditionally-used as an energizing vegetable with therapeutic properties for both men and women. Maca has been recognized by natives of Peru as herbal remedy helping to treat conditions affecting menopausal women. The effects of Pre-Gelatinized Organic Maca (Maca-GO) on quantitative physiological responses and alleviation of symptoms contributing to menopausal discomfort in perimenopausal women was examined. IN THIS, FOUR MONTHS, DOUBLE BLIND, CROSSOVER, RANDOMIZED PILOT TRIAL, MONTHLY MEASUREMENTS OF THE FOLLOWING BLOOD SERUM CONSTITUENTS WERE TAKEN: Estrogen (E2), Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and Progesterone (PGS), Cortisol (CT), Adrenocorticotropic Hormone (ACTH), Thyroid Hormones (TSH, T3, T4), minerals (Ca, K, Fe) and lipid profile (Triglicerides, Total Cholesterol, LDL, HDL). In monthly interviews conducted by gynecologist, body weight and blood pressure were registered and Menopausal Index according to Kupperman's was determined. Toxicity of Maca -GO determined on rats showed its safe use at the level of 7.5mg/kg body weight. A group of 20 women (aged 41-50 years), who fulfilled criteria of being in perimenopausal stage (E2 above 40pg/ml and FSH below 30IU/ml), were randomly allocated to two even groups, one receiving for two months Maca-GO and the other Placebo capsules followed by a crossover with treatment change for another two months period. All participants signed informed consent to participate. Two 500mg hard capsules with Maca-GO or Placebo were self-administered by participants twice daily with meals (total 2g/day). Two months administration of Maca-GO significantly alleviated symptoms of discomfort observed in majority of women involved in the study (74%-87%) as assessed by Kupperman's Menopausal index. This was associated with significant increase in E2 and FSH, Progesterone

  4. The transillumination technique as a method for the assessment of spermatogenesis using medicinal plants: the effect of extracts of black maca (Lepidium meyenii) and camu camu (Myrciaria dubia) on stages of the spermatogenic cycle in male rats.

    Science.gov (United States)

    Gonzales, Gustavo F; Vasquez, Vanessa Bertha; Gasco, Manuel

    2013-10-01

    Transillumination technique for assessment of stages of spermatogenic cycle is a useful tool for toxicological studies. This study was designed to determine the effect of two medicinal plants on spermatogenesis in male rats using the transillumination technique. For this, the effect of the combination of a fruit with highest content of ascorbic acid (Myrciaria dubia, camu camu) and extract of black maca (Lepidium meyenii) on seminiferous tubule stages scored by transillumination on intact tubules in adult male rats was assessed. Animals were treated during seven days with vehicle, black maca, camu camu or a mixture of black maca + camu camu and assessed for daily sperm production (DSP), stages of spermatogenic cycle as well as antioxidant activity and levels of flavonoids and polyphenols. Black maca increased stages of spermiation (VII-VIII) and mitosis of germ cells (IX-XI), whereas camu camu increased stages of mitosis (IX-XI) and meiosis (XII). Mixture of maca + camu camu increased stages of spermiation, mitosis and meiosis. All treatments increased DSP (p<0.05) and epididymal sperm count (p<0.05). Total polyphenols, flavonoids levels and antioxidant activity were higher in camu camu (p<0.001) than in black maca. In conclusion, M. dubia (camu camu) has potential effects improving spermatogenesis and co-administered with maca increase stages of mitosis, meiosis and spermiation of the spermatogenic cycle as assessed by the transillumination technique. This technique is becoming increasingly a useful tool for assessment spermatogenesis.

  5. Effect of organic fertilizers on quality and quantity characteristics of blond psyllium (Plantago ovata Forssk. clasping peperweed (Lepidium perfoilatum L., qodumeh Shirazi (Alyssum homolocarpum L. and dragon's head (Lalementia iberica L.

    Directory of Open Access Journals (Sweden)

    A. Koocheki

    2016-05-01

    Full Text Available This experiment was carried out in experimental farm of Agricultural Faculty of Ferdowsi University of Mashhad, Iran during 2010. The design was split plot with three replications. Main plots were the medicinal plant species consist of: blond psyllium (Plantago ovate Forssk., clasping peperweed (Lepidium perfoilatum L., qodumeh Shirazi (Alyssum homolocarpum L. dragon's head (Lalementia iberica L. and subplots were various organic fertilizer consist of cow manure, vermicompost (based on cow manure, coffee compost and spent mushroom compost. Results showed that medicinal plants had significant difference for number of seeds per plant, shoot dry matter, seed yield, plant height and mucilage percentage. Effect of various organic matter on all traits except for 1000-seed weight was significant. Interaction of organic fertilizers and plant was significant for dry matter. Lalementia had the most mucilage percentage (27.75% and cow manure was the best fertilizer because it had the highest amounts of dry matter (1816 kg.ha-1, seed yield (467.5 kg.ha-1, number seed per plant (550 seeds.plant-1, plant height (23.17 cm and mucilage percentage (20.75%.

  6. Shared and host-specific microbiome diversity and functioning of grapevine and accompanying weed plants.

    Science.gov (United States)

    Samad, Abdul; Trognitz, Friederike; Compant, Stéphane; Antonielli, Livio; Sessitsch, Angela

    2017-04-01

    Weeds and crop plants select their microbiota from the same pool of soil microorganisms, however, the ecology of weed microbiomes is poorly understood. We analysed the microbiomes associated with roots and rhizospheres of grapevine and four weed species (Lamium amplexicaule L., Veronica arvensis L., Lepidium draba L. and Stellaria media L.) growing in proximity in the same vineyard using 16S rRNA gene sequencing. We also isolated and characterized 500 rhizobacteria and root endophytes from L. draba and grapevine. Microbiome data analysis revealed that all plants hosted significantly different microbiomes in the rhizosphere as well as in root compartment, however, differences were more pronounced in the root compartment. The shared microbiome of grapevine and the four weed species contained 145 OTUs (54.2%) in the rhizosphere, but only nine OTUs (13.2%) in the root compartment. Seven OTUs (12.3%) were shared in all plants and compartments. Approximately 56% of the major OTUs (>1%) showed more than 98% identity to bacteria isolated in this study. Moreover, weed-associated bacteria generally showed a higher species richness in the rhizosphere, whereas the root-associated bacteria were more diverse in the perennial plants grapevine and L. draba. Overall, weed isolates showed more plant growth-promoting characteristics compared with grapevine isolates. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Cruciferous weeds in oil seed rape – appearance and control

    Directory of Open Access Journals (Sweden)

    Klingenhagen, Günter

    2014-02-01

    Full Text Available Different cruciferous weeds were drilled in autumn 2011 and 2012 in a field near Münster. Beside common species like hedge mustard (Sisymbrium officinale Scop., shepherd`s purse (Capsella bursa-pastoris, pennycress (Thlaspiarvense, tall hedge mustard (Sisymbrium loeselii and flixweed (Descurainia sophia, we tried to establish weeds that are not common on arable land in Germany until now. These were: Yellow rocket (Barbarea vulgaris, hoary cress (Lepidium draba and Turkish rocket (Bunias orientalis. In autumn 2011 emergence of the sown weeds was poor. In the second year of experiment we got good emergence of the named weeds excluding hoary cress (Lepidium draba. In autumn 2011 and 2012 different herbicidecombinations were applied across the stripes. The best results were achieved with Colzor Trio (clomazone + dimethachlor + napropamid which was applied in pre-emergence state, a spray sequence Butisan Gold (metazachlor + quinmerac + dimethenamid-P applied in pre-emergence followed by Salsa (ethametsulfuronmethyl + Trend (adjuvant in post-emergence and Clearfield-Vantiga (metazachlor + quinmerac + imazamox + Dash (adjuvant, also applied in post-emergence state of the weeds.

  8. Red Maca (Lepidium meyenii) did not affect cell viability despite increased androgen receptor and prostate-specific antigen gene expression in the human prostate cancer cell line LNCaP.

    Science.gov (United States)

    Díaz, P; Cardenas, H; Orihuela, P A

    2016-10-01

    We examined whether aqueous extract of Lepidium meyenii (red Maca) could inhibit growth, potentiate apoptotic activity of two anticancer drugs Taxol and 2-methoxyestradiol (2ME) or change mRNA expression for the androgen target genes, androgen receptor (Ar) and prostate-specific antigen (Psa) in the human prostate cancer cell line LNCaP. Red Maca aqueous extract at 0, 10, 20, 40 or 80 μg/ml was added to LNCaP cells, and viability was evaluated by the MTS assay at 24 or 48 hr after treatment. Furthermore, LNCaP cells were treated with 80 μg/ml of red Maca plus Taxol or 2ME 5 μM and viability was assessed 48 hr later. Finally, LNCaP cells were treated with red Maca 0, 20, 40 or 80 μg/ml, and 12 hr later, mRNA level for Ar or Psa was assessed by real-time PCR. Treatment with red Maca did not affect viability of LNCaP cells. Apoptotic activity induced by Taxol and 2ME in LNCaP cells was not altered with red Maca treatment. Relative expression of the mRNA for Ar and Psa increased with red Maca 20 and 40 μg/ml, but not at 80 μg/ml. We conclude that red Maca aqueous extract does not have toxic effects, but stimulates androgen signalling in LNCaP cells. © 2016 Blackwell Verlag GmbH.

  9. Molecular cloning, characterization and analysis of the intracellular localization of a water-soluble chlorophyll-binding protein (WSCP) from Virginia pepperweed (Lepidium virginicum), a unique WSCP that preferentially binds chlorophyll b in vitro.

    Science.gov (United States)

    Takahashi, Shigekazu; Yanai, Haruna; Oka-Takayama, Yuko; Zanma-Sohtome, Aya; Fujiyama, Kosaku; Uchida, Akira; Nakayama, Katsumi; Satoh, Hiroyuki

    2013-12-01

    Various plants possess non-photosynthetic, hydrophilic chlorophyll (Chl) proteins called water-soluble Chl-binding proteins (WSCPs). WSCPs are categorized into two classes; Class I (photoconvertible type) and Class II (non-photoconvertible type). Among Class II WSCPs, only Lepidium virginicum WSCP (LvWSCP) exhibits a low Chl a/b ratio compared with that found in the leaf. Although the physicochemical properties of LvWSCP have been characterized, its molecular properties have not yet been documented. Here, we report the characteristics of the LvWSCP gene, the biochemical properties of a recombinant LvWSCP, and the intracellular localization of LvWSCP. The cloned LvWSCP gene possesses a 669-bp open reading frame. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis revealed that the precursor of LvWSCP contains both N- and C-terminal extension peptides. RT-PCR analysis revealed that LvWSCP was transcribed in various tissues, with the levels being higher in developing tissues. A recombinant LvWSCP and hexa-histidine fusion protein (LvWSCP-His) could remove Chls from the thylakoid in aqueous solution and showed an absorption spectrum identical to that of native LvWSCP. Although LvWSCP-His could bind both Chl a and Chl b, it bound almost exclusively to Chl b when reconstituted in 40 % methanol. To clarify the intracellular targeting functions of the N- and C-terminal extension peptides, we constructed transgenic Arabidopsis thaliana lines expressing the Venus protein fused with the LvWSCP N- and/or C-terminal peptides, as well as Venus fused at the C-terminus of LvWSCP. The results showed that the N-terminal peptide functioned in ER body targeting, while the C-terminal sequence did not act as a trailer peptide.

  10. Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii) in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study.

    Science.gov (United States)

    Gonzales-Arimborgo, Carla; Yupanqui, Irma; Montero, Elsa; Alarcón-Yaquetto, Dulce E; Zevallos-Concha, Alisson; Caballero, Lidia; Gasco, Manuel; Zhao, Jianping; Khan, Ikhlas A; Gonzales, Gustavo F

    2016-08-18

    The plant maca, grown at 4000 m altitude in the Peruvian Central Andes, contains hypocotyls that have been used as food and in traditional medicine for centuries. The aim of this research was to provide results on some health effects of oral administration of spray-dried extracts of black or red maca (Lepidium meyenii) in adult human subjects living at low (LA) and high altitude (HA). A total of 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks. Primary outcomes were changes in sexual desire, mood, energy, health-related quality of life score (HRQL), and chronic mountain sickness (CMS) score, or in glycaemia, blood pressure, and hemoglobin levels. Secondary outcomes were acceptability and safety, assessed using the Likert test and side effect self-recording, respectively, and the effect of altitude. At low altitude, 32, 30, and 32 participants started the study receiving placebo, red maca, or black maca, respectively. At high altitudes, 33, 35, and 31 participants started the study receiving placebo, red maca, and black maca, respectively. Consumption of spray-dried extracts of red and black maca resulted in improvement in mood, energy, and health status, and reduced CMS score. Fatty acids and macamides were higher in spray-dried extracts of black maca than in red maca. GABA predominated in spray-dried extracts of red maca. Effects on mood, energy, and CMS score were better with red maca. Black maca and, in smaller proportions, red maca reduced hemoglobin levels only in highlanders with abnormally high hemoglobin levels; neither variety of maca reduced hemoglobin levels in lowlanders. Black maca reduced blood glucose levels. Both varieties produced similar responses in mood, and HRQL score. Maca extracts consumed at LA or HA had good acceptability and did not show serious adverse effects. In conclusion, maca extract consumption relative to the placebo improved quality of life parameters. Differences in the level of

  11. Acceptability, Safety, and Efficacy of Oral Administration of Extracts of Black or Red Maca (Lepidium meyenii in Adult Human Subjects: A Randomized, Double-Blind, Placebo-Controlled Study

    Directory of Open Access Journals (Sweden)

    Carla Gonzales-Arimborgo

    2016-08-01

    Full Text Available The plant maca, grown at 4000 m altitude in the Peruvian Central Andes, contains hypocotyls that have been used as food and in traditional medicine for centuries. The aim of this research was to provide results on some health effects of oral administration of spray-dried extracts of black or red maca (Lepidium meyenii in adult human subjects living at low (LA and high altitude (HA. A total of 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks. Primary outcomes were changes in sexual desire, mood, energy, health-related quality of life score (HRQL, and chronic mountain sickness (CMS score, or in glycaemia, blood pressure, and hemoglobin levels. Secondary outcomes were acceptability and safety, assessed using the Likert test and side effect self-recording, respectively, and the effect of altitude. At low altitude, 32, 30, and 32 participants started the study receiving placebo, red maca, or black maca, respectively. At high altitudes, 33, 35, and 31 participants started the study receiving placebo, red maca, and black maca, respectively. Consumption of spray-dried extracts of red and black maca resulted in improvement in mood, energy, and health status, and reduced CMS score. Fatty acids and macamides were higher in spray-dried extracts of black maca than in red maca. GABA predominated in spray-dried extracts of red maca. Effects on mood, energy, and CMS score were better with red maca. Black maca and, in smaller proportions, red maca reduced hemoglobin levels only in highlanders with abnormally high hemoglobin levels; neither variety of maca reduced hemoglobin levels in lowlanders. Black maca reduced blood glucose levels. Both varieties produced similar responses in mood, and HRQL score. Maca extracts consumed at LA or HA had good acceptability and did not show serious adverse effects. In conclusion, maca extract consumption relative to the placebo improved quality of life parameters. Differences in

  12. Draba alshehbazii (Brassicaceae), a new species from extreme altitudes of eastern Ladakh (Jammu and Kashmir, India)

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Leoš; German, D.

    2008-01-01

    Roč. 158, č. 4 (2008), s. 749-754 ISSN 0024-4074 R&D Projects: GA ČR GA206/03/1219; GA AV ČR IAA600050802 Institutional research plan: CEZ:AV0Z60050516 Keywords : Cruciferae * Pangong * Rupshu * taxonomy Subject RIV: EF - Botanics Impact factor: 1.189, year: 2008

  13. Effect of high hydrostatic pressure on seed germination, microbial quality, anatomy-morphology and physiological characteristics of garden cress (Lepidium sativum) seedlings

    Science.gov (United States)

    İşlek, Cemil; Murat Altuner, Ergin; Çeter, Talip; Alpas, Hami

    2013-06-01

    High hydrostatic pressure is a non-thermal food processing technology that is found to increase the percentage of germination, decrease the germination time and improve the microbial quality of seeds. In this study, pressures of 100-400 MPa for 10 min at 30°C are used to compare the percentage of germination, the microbial quality of seeds, chlorophyll a and b, and total phenolic compounds concentrations in seedlings, and the anatomy-morphology characteristics of garden cress. Enhanced reductions of total aerobic mesophilic bacteria, total and fecal coliforms, and yeast and mould populations in seeds were observed, especially at 300 MPa. In addition, the percentage of germination, chlorophyll content and phenolic compounds concentrations, fresh and dry weights, and hypocotyl lengths of the seedlings are higher than those of all samples, where the percentage of germination is equal to controls but higher than other samples, and radicula length is lower than controls but higher than others.

  14. Population Ethics

    OpenAIRE

    BLACKORBY, Charles; BOSSERT, Walter; DONALDSON, David

    2006-01-01

    This paper reviews the welfarist approach to population ethics. We provide an overview of the critical-level utilitarian population principles and their generalized counterparts, examine important properties of these principles and discuss their relationships to other variable-population social-evaluation rules. We illustrate the difficulties arising in population ethics by means of an impossibility result and present characterizations of the critical-level generalized-utilitarian principles ...

  15. Population Research.

    Science.gov (United States)

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  16. Population Education.

    Science.gov (United States)

    Shashidhar, B.; And Others

    Population education has assumed enormous importance in the national and international arena, since population changes influence the quality of life of individuals, families, the nation and the world as a whole. Population education has, however, special significance to India since young persons below the age of 15 are reported to form about 42%…

  17. [Population education].

    Science.gov (United States)

    1977-01-01

    Goal of population education is to raise knowledge and comprehension of causes and consequences, either personal or social, of excessive population growth. These days it is possible to plan the growth and evolution of the population to reach a level of balance and harmony between number of inhabitants of a country, and the country's natural resoruces. general objectives of population education are: 1) knowledge of basic demographic processes; 2) knowledge of effects of evolution and growth of population on social and economic life inside the family and inside society; 3) family size as related to nutrition, health, education, and job; and, 4) knowledge of population dynamics which the individual can influence through personal behavior, i.e. age at marriage, and spacing and number of children.

  18. Imaginary populations

    OpenAIRE

    Martínez-Abraín, Alejandro

    2010-01-01

    A few years ago, Camus & Lima (2002) wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002), that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologis...

  19. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  20. PROXIMATE ANALYSIS OF LEPIDIUM SATIVUM LEAVES

    African Journals Online (AJOL)

    HANIF BELLO

    fats and fiber. Therefore, this plant is recommended for consumers as vegetable in their diet so as to meet up the body nutrients demand. Keywords: Proximate .... they are useless as foods (Oliver, 2002). The crude fiber result showed L. sativum to contain 8.69±0.01% fiber content. As an important part of any diet, fiber.

  1. [Recent researching progress of Lepidium meyenii (Maca)].

    Science.gov (United States)

    Zhou, Yan-yan; Zhao, Hai-yu; Si, Nan; Wang, Hong-jie; Gian, Bao-lin

    2015-12-01

    Maca as one of the star products in the international health care market in recent years, had a wide range of application value and promoted to all over the world. However, the basic research of Maca was not deep, lack of systematic and clear efficacy studies. Market products hype its aphrodisiac effect, which greatly impact more systematic in-depth research and exploration. Therefore, this paper briefly summarizes advance research in recent years including the status quo of the resources, growth cultivation, phytochemical, pharmacological effect and other aspects, which can provide reference for rational development and utilization of Maca.

  2. Population crises and population cycles.

    Science.gov (United States)

    Russell, C; Russell, W M

    2000-01-01

    To prevent a population irretrievably depleting its resources, mammals have evolved a behavioural and physiological response to population crisis. When a mammalian population becomes dangerously dense, there is a reversal of behaviour. Co-operation and parental behaviour are replaced by competition, dominance and aggressive violence, leading to high mortality, especially of females and young, and a reduced population. The stress of overpopulation and the resulting violence impairs both the immune and the reproductive systems. Hence epidemics complete the crash of the population, and reproduction is slowed for three or four generations, giving the resources ample time to recover. In some mammal species, crisis and crisis response recur regularly, leading to cycles of population growth and relapse, oscillating about a fixed mean. Population crisis response and population cycles have been equally prominent in the history of human societies. But in man successive advances in food production have made possible growing populations, though with every such advance population soon outgrew resources again. Hence human cycles have been superimposed on a rising curve, producing a saw-tooth graph. Because advances in food production amounted to sudden disturbances in the relations between human populations and their environments, the crisis response in man has failed to avert famine and resource damage. In the large human societies evolved since the coming of settled agriculture and cities, the basic effects of violence, epidemics, famine and resource damage have been mediated by such specifically human disasters as inflation, unemployment, and political tyranny. An account of past crises, periods of relative relief from population pressure, and resulting cycles, is given for a number of regions: China, North Africa and Western Asia, the northern Mediterranean, and north-western Europe. The paper ends with an account of the present world-wide population crisis, and the solution

  3. Imaginary populations

    Directory of Open Access Journals (Sweden)

    A. Martínez–Abraín

    2010-01-01

    Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably

  4. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  5. Population dynamics

    Directory of Open Access Journals (Sweden)

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

  6. Populations games

    Czech Academy of Sciences Publication Activity Database

    Křivan, Vlastimil

    2015-01-01

    Roč. 2, č. 1 (2015), s. 14-19 ISSN 2367-5233. [Featuring International Conferences Biomath 2015. Blagoevgrad, 14.06.2015-19.06.2015] R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : populations dynamics

  7. Stellar Populations

    NARCIS (Netherlands)

    Peletier, Reynier F.

    2013-01-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on

  8. MAIZE POPULATIONS

    African Journals Online (AJOL)

    2003-06-17

    Jun 17, 2003 ... This study compared two maize populations, ZM601 and. ZM607 for drought tolerance during flowering, the most drought-vulnerable period for the maize plant. Cultivar. ZM601 had been improved through ...... Banziger, M., Pixley, K.V. and Zambezi, B.T.. 1999. Drought andNstress tolerance of maize.

  9. Population Aging

    OpenAIRE

    David Weil

    2006-01-01

    Population aging is primarily the result of past declines in fertility, which produced a decades long period in which the ratio of dependents to working age adults was reduced. Rising old-age dependency in many countries represents the inevitable passing of this %u201Cdemographic dividend.%u201D Societies use three methods to transfer resources to people in dependent age groups: government, family, and personal saving. In developed countries, families are predominant in supporting children, w...

  10. Stickleback Population

    Directory of Open Access Journals (Sweden)

    Ulrika Candolin

    2012-01-01

    Full Text Available Human-induced eutrophication has increased offspring production in a population of threespine stickleback Gasterosteus aculeatus in the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perch Perca fluviatilis (behind a transparent Plexiglas wall. However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.

  11. Bacteriophage populations

    International Nuclear Information System (INIS)

    Klieve, A.V.; Gilbert, R.A.

    2005-01-01

    Bacteriophages are ubiquitous to the rumen ecosystem; they have a role in nitrogen metabolism through bacterial lysis in the rumen, they may help to regulate bacterial population densities, be an agent for genetic exchange and be of use in biocontrol of bacterial populations through phage therapy. In Chapter 2.1, classical methodologies to enable the isolation, enumeration, storage and morphological characterization of phages were presented. In addition to these classic procedures, molecular biological techniques have resulted in a range of methodologies to investigate the type, topology and size of phage nucleic acids, to fingerprint individual phage strains and to create a profile of ruminal phage populations. Different phage families possess all the currently identified combinations of double-stranded or single-stranded RNA or DNA and may also possess unusual bases such as 5-hydroxymethylcytosine (found in T-even phage) or 5- hydroxymethyluracil and uracil in place of thymidine. In all morphological groups of phage except the filamentous phages, the nucleic acid is contained within a head or polyhedral structure, predominantly composed of protein. Filamentous phages have their nucleic acid contained inside the helical filament, occupying much of its length. Many of the procedures used with phage nucleic acids and double-stranded (ds) DNA, in particular, are not specific to ruminal phages but are the same as in other areas where nucleic acids are investigated and are covered elsewhere in the literature and this chapter. Most applications with rumen phages are similar to those reported for phages of non-ruminal bacteria and are covered in general texts such as Maniatis et al. In this chapter, we will concentrate on aspects of methodology as they relate to ruminal phages

  12. Indian populations

    CERN Document Server

    Spahni,J

    1974-01-01

    Le Prof. J.C. Spahni qui a parcouru les Andes, Vénezuela etc. parle de ses expériences et connaissances qu'il a vécu au cours des 14 ans parmi les populations indiennes de la Cordillière des Andes. Il a ramené des objets artisanals indiens lesquels l'auditoire peut acquérir. L'introduction-conférence est suivi d'un film, commenté par lui-même; après l'entracte il y un débat-dialogue avec le public.

  13. The C-terminal extension peptide of non-photoconvertible water-soluble chlorophyll-binding proteins (Class II WSCPs) affects their solubility and stability: comparative analyses of the biochemical and chlorophyll-binding properties of recombinant Brassica, Raphanus and Lepidium WSCPs with or without their C-terminal extension peptides.

    Science.gov (United States)

    Takahashi, Shigekazu; Uchida, Akira; Nakayama, Katsumi; Satoh, Hiroyuki

    2014-02-01

    Numerous members of the Brassicaceae possess non-photoconvertible water-soluble chlorophyll (Chl)-binding proteins (Class II WSCPs), which function as Chl scavengers during cell disruption caused by wounding, pest/pathogen attacks, and/or environmental stress. Class II WSCPs have two extension peptides, one at the N-terminus and one at the C-terminus. The N-terminal peptide acts as a signal peptide, targeting the protein to the endoplasmic reticulum body, a unique defensive organelle found only in the Brassicaceae. However, the physiological and biochemical functions of the C-terminal extension peptide had not been characterized previously. To investigate the function of the C-terminal extension peptide, we produced expression constructs of recombinant WSCPs with or without the C-terminal extension peptide. The WSCPs used were of Brussels sprouts (Brassica oleracea), Japanese wild radish (Raphanus sativus) and Virginia pepperweed (Lepidium virginicum). The solubility of all of the WSCPs with the C-terminal extension peptide was drastically lower than that of the recombinant WSCPs without the C-terminal extension peptide. In addition, the stability of the reconstituted WSCPs complexes with the C-terminal extension peptide was altered compared with that of the proteins without the C-terminal extension peptide. These finding indicate that the C-terminal extension peptide affects not only the solubility, but also the stability of Class II WSCP. Furthermore, we characterized the Chl-binding properties of the recombinant WSCP from Japanese wild radish (RshWSCP-His) in a 40 % methanol solution. An electrophoretic mobility shift assay revealed that RshWSCP-His required a half-molar ratio of Chls to form a tetramer.

  14. Population growth rates in perfect contraceptive populations.

    Science.gov (United States)

    Udry, J R; Bauman, K E; Chase, C L

    1973-07-01

    Abstract Eventually, world population must cease to grow. In many countries attempts are made to decrease population growth by providing family planning services to all who want to prevent pregnancies. In this paper we use the concept 'perfect contraceptive population',(1) - a population in which no unwanted births occur - to derive estimates of the maximum contribution that prevention of unwanted births might make toward attaining a zero rate of natural increase in population.

  15. Population Genetics with Fluctuating Population Sizes

    OpenAIRE

    Chotibut, Thiparat; Nelson, David R.

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges natural...

  16. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  17. Population Education Country Programmes.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Describes population programs in Afghanistan (nonformal, population education literacy program), India (problems in planning/managing population education in higher education), Indonesia (training for secondary/out-of-school inspectors), and Pakistan (integration of population education into school curricula). Programs in China, Korea, Vietnam,…

  18. Why Population in 1974?

    Science.gov (United States)

    O'Connor, Marion

    1974-01-01

    Discusses the impact of world population growth leading to the establishment of the United Nations Fund for Population Activities and to the declaration of 1974 as World Population Year. Previews some of the parameters and interconnecting interests to be considered during this year of intensive population study. (JR)

  19. Population and population policy in Pakistan.

    Science.gov (United States)

    Mauldin, W P

    1963-02-01

    Pakistan is a divided country with different religious groups represented. Since independence in 1941, the Muslim population has increased more rapidly than the Hindu population, the West Pakistan population more rapidly and steadily than the East Pakistan population. In the late 1950s the Pakistan government initiated a family planning program. The program has trained medical and paramedical personnel in family planning, added family planning services to existing medical centers, planned for a National Research Institute of Family Planning, employed mobile units to reach outlying areas, conducted limited clinical studies on some contraceptives, and used mass media advertising. Only India and Japan are doing more with government-sponsored family planning. A weak organizational structure and an inadequate number of trained personnel are the main weakness of the program. It is too early to assess the success of the program. A 10-point reduction in annual birth rates will be considered successful.

  20. Population and Environment

    OpenAIRE

    de Sherbinin, Alex; Carr, David; Cassels, Susan; Jiang, Leiwen

    2007-01-01

    The interactions between human population dynamics and the environment have often been viewed mechanistically. This review elucidates the complexities and contextual specificities of population-environment relationships in a number of domains. It explores the ways in which demographers and other social scientists have sought to understand the relationships among a full range of population dynamics (e.g., population size, growth, density, age and sex composition, migration, urbanization, vital...

  1. Iowa Population Trends.

    Science.gov (United States)

    Tait, John L.; Johnson, Arthur H.

    The trends in population distribution and the composition of Iowa's population are reported in this document in order to provide the leaders and citizens of Iowa with information to assist them in making decisions relating to growth and development. Birth and death rates, rural and urban residence, population by race, and age structure are…

  2. [Population Growth and Development].

    Science.gov (United States)

    Clausen, A. W.

    Rapid population growth as a central development problem, the proper domain of government in reducing population growth, and effective measures which can be taken to reduce fertility are examined. Rapid population growth puts a brake on development because it exacerbates the difficult choice between higher consumption now and the investment needed…

  3. Controlling Population with Pollution

    Science.gov (United States)

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  4. [Population policies and population trends in China].

    Science.gov (United States)

    Pressat, R

    1983-04-01

    Although relatively little has been known about the Chinese population in recent centuries, figures are available for more remote times. In the year 2 the Chinese population was recorded at 60 million. In 1928, when the last pre-Revolution census was conducted, China had a population of 475 million. The population was not believed to have grown very much due to internal disorders, war, and foreigh invasion, but the 1953 census counted 582 million to which were added 18 million to include Taiwan and overseas Chinese. The figure of 600 million appears to mark the beginning of concern over demographic problems. The crude birth rate was estimated at 37/1000 and the death rate at 17/1000. The 1953 census was conducted with Soviet aid and was given some publicity. The period 1953-58 was marked by a mortality decline and a steady fertility rate, but the population is believed to have declined from 647 million in 1958 to 643 million in 1962, the end of the Great Leap Forward. A census suppressed until recently gave a total of 694 million for 1964. Population growth was considerable from 1961-66. In the 1st part of the Cultural Revolution from 1966-70, no effort was made to control population growth; in 1971, the crude birth rate was estimated at 30-35/1000, the mortality rate was 8/1000, and the growth rate was 2.6%. 1971-79 marked the 1st phase of birth limitation, which became more pressing with time. The population was counted at 1 billion 8 million in 1982, with a birth rate of 21/1000, a death rate of 6/1000, and a growth rate of 1.5%. Because of China's comprehensive system of population registration, the results of the 1982 census were not completely unexpected. Wide differences in growth rates were noted between provinces, and the minorities grew at a faster rate than the Han majority. Immediately after the Revolution, population was relatively neglected in China in favor of greater attention to economic growth. The 1st warnings about the consequences of overly

  5. Peru: population and policy.

    Science.gov (United States)

    Sobrevilla, L A

    1987-06-01

    Peru's 1985 Population Policy Law states as its second objective that individuals and couples should be well informed and provided with the education and health services that will assist them in making responsible decisions about the number and spacing of their children. Thus, the law establishes a firm basis for IEC programs. With regard to population education, the purpose of the law is to create awareness through all educational channels of the reciprocal influence of population dynamics and socioeconomic development and to promote positive attitudes toward small family size. The law promotes the use of the communications media to educate and inform about population issues. The National Population Council, which coordinates and supervises the IEC activities of public sector agencies, has issued publications and audiovisual materials, conducted meetings with government officials and opinion leaders, and promoted awareness of population policy as a key part of development planning. In 1984, the Council organized the First National Seminar on Communication and Population to review activities, set the basis for intersectoral coordination, unify criteria, and review population policy concepts and language. The Ministry of Health carries out IEC activities as part of its family planning services program. In addition, the Ministry of Education has organized a national population education program that aims to revise school curricula to include a greater emphasis on population dynamics and family life education. The activities of a number of private institutions complement the IEC work public sector organizations.

  6. Molecular Population Genetics.

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  7. Molecular Population Genetics

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  8. Red maca (Lepidium meyenii) reduced prostate size in rats

    Science.gov (United States)

    Gonzales, Gustavo F; Miranda, Sara; Nieto, Jessica; Fernández, Gilma; Yucra, Sandra; Rubio, Julio; Yi, Pedro; Gasco, Manuel

    2005-01-01

    Background Epidemiological studies have found that consumption of cruciferous vegetables is associated with a reduced risk of prostate cancer. This effect seems to be due to aromatic glucosinolate content. Glucosinolates are known for have both antiproliferative and proapoptotic actions. Maca is a cruciferous cultivated in the highlands of Peru. The absolute content of glucosinolates in Maca hypocotyls is relatively higher than that reported in other cruciferous crops. Therefore, Maca may have proapoptotic and anti-proliferative effects in the prostate. Methods Male rats treated with or without aqueous extracts of three ecotypes of Maca (Yellow, Black and Red) were analyzed to determine the effect on ventral prostate weight, epithelial height and duct luminal area. Effects on serum testosterone (T) and estradiol (E2) levels were also assessed. Besides, the effect of Red Maca on prostate was analyzed in rats treated with testosterone enanthate (TE). Results Red Maca but neither Yellow nor Black Maca reduced significantly ventral prostate size in rats. Serum T or E2 levels were not affected by any of the ecotypes of Maca assessed. Red Maca also prevented the prostate weight increase induced by TE treatment. Red Maca administered for 42 days reduced ventral prostatic epithelial height. TE increased ventral prostatic epithelial height and duct luminal area. These increases by TE were reduced after treatment with Red Maca for 42 days. Histology pictures in rats treated with Red Maca plus TE were similar to controls. Phytochemical screening showed that aqueous extract of Red Maca has alkaloids, steroids, tannins, saponins, and cardiotonic glycosides. The IR spectra of the three ecotypes of Maca in 3800-650 cm (-1) region had 7 peaks representing 7 functional chemical groups. Highest peak values were observed for Red Maca, intermediate values for Yellow Maca and low values for Black Maca. These functional groups correspond among others to benzyl glucosinolate. Conclusions Red Maca, a cruciferous plant from the highland of Peru, reduced ventral prostate size in normal and TE treated rats. PMID:15661081

  9. Lepidium meyenii (Maca) does not exert direct androgenic activities.

    Science.gov (United States)

    Bogani, P; Simonini, F; Iriti, M; Rossoni, M; Faoro, F; Poletti, A; Visioli, F

    2006-04-06

    Maca is the edible root of the Peruvian plant Lepidum meyenii, traditionally employed for its purported aphrodisiac and fertility-enhancing properties. This study aimed at testing the hypothesis that Maca contains testosterone-like compounds, able to bind the human androgen receptor and promote transcription pathways regulated by steroid hormone signaling. Maca extracts (obtained with different solvents: methanol, ethanol, hexane and chloroform) are not able to regulate GRE (glucocorticoid response element) activation. Further experiments are needed to assess which compound, of the several Maca's components, is responsible of the observed in vivo effects.

  10. Antiviral activity of maca (Lepidium meyenii) against human influenza virus.

    Science.gov (United States)

    Del Valle Mendoza, Juana; Pumarola, Tomàs; Gonzales, Libertad Alzamora; Del Valle, Luis J

    2014-09-01

    To investigate antiviral activity of maca to reduce viral load in Madin-Darby canine kidney (MDCK) cells infected with influenza type A and B viruses (Flu-A and Flu-B, respectively). Maca were extracted with methanol (1:2, v/v). The cell viability and toxicity of the extracts were evaluated on MDCK cells using method MTT assay. Antiviral activity of compounds against Flu-A and Flu-B viruses was assayed using a test for determining the inhibition of the cytopathic effect on cell culture and multiplex RT-PCR. The methanol extract of maca showed low cytotoxicity and inhibited influenza-induced cytopathic effect significantly, while viral load was reduced via inhibition of viral growth in MDCK infected cells. Maca contains potent inhibitors of Flu-A and Flu-B with a selectivity index [cytotoxic concentration 50%/IC50] of 157.4 and 110.5, respectively. In vitro assays demonstrated that maca has antiviral activity not only against Flu-A (like most antiviral agents) but also Flu-B viruses, providing remarkable therapeutic benefits. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  11. The Methyltetrahydro-β-Carbolines in Maca (Lepidium meyenii)

    Science.gov (United States)

    Gonzales-Castañeda, Cynthia

    2009-01-01

    Maca, a plant native to the Peruvian highlands, contains (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA). The family of the tetrahydro-β-carbolines has been associated with both biologically helpful and harmful compounds. We present evidence that MTCA is a natural constituent of Maca, and on consumption no toxicity is found. This suggests that, when consumed as multi-component, MTCA may loose its adversity as drug action. PMID:18955346

  12. Determination of Nutritive Values of Garden Cress ( Lepidium ...

    African Journals Online (AJOL)

    1850.00 mg/100g), calcium (829.13 mg/100g), magnesium (160.60 mg/100g), sodium (141.13 mg/100g) and iron (63.47 mg/100g) with low level of phosphorus (4.10 mg/100g), manganese (5.74 mg/100g), copper (0.39 mg/100g) and chromium ...

  13. The Methyltetrahydro-β-Carbolines in Maca (Lepidium meyenii

    Directory of Open Access Journals (Sweden)

    Gustavo F. Gonzales

    2009-01-01

    Full Text Available Maca, a plant native to the Peruvian highlands, contains (1R,3S-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA. The family of the tetrahydro-β-carbolines has been associated with both biologically helpful and harmful compounds. We present evidence that MTCA is a natural constituent of Maca, and on consumption no toxicity is found. This suggests that, when consumed as multi-component, MTCA may loose its adversity as drug action.

  14. Red maca (Lepidium meyenii reduced prostate size in rats

    Directory of Open Access Journals (Sweden)

    Rubio Julio

    2005-01-01

    Full Text Available Abstract Background Epidemiological studies have found that consumption of cruciferous vegetables is associated with a reduced risk of prostate cancer. This effect seems to be due to aromatic glucosinolate content. Glucosinolates are known for have both antiproliferative and proapoptotic actions. Maca is a cruciferous cultivated in the highlands of Peru. The absolute content of glucosinolates in Maca hypocotyls is relatively higher than that reported in other cruciferous crops. Therefore, Maca may have proapoptotic and anti-proliferative effects in the prostate. Methods Male rats treated with or without aqueous extracts of three ecotypes of Maca (Yellow, Black and Red were analyzed to determine the effect on ventral prostate weight, epithelial height and duct luminal area. Effects on serum testosterone (T and estradiol (E2 levels were also assessed. Besides, the effect of Red Maca on prostate was analyzed in rats treated with testosterone enanthate (TE. Results Red Maca but neither Yellow nor Black Maca reduced significantly ventral prostate size in rats. Serum T or E2 levels were not affected by any of the ecotypes of Maca assessed. Red Maca also prevented the prostate weight increase induced by TE treatment. Red Maca administered for 42 days reduced ventral prostatic epithelial height. TE increased ventral prostatic epithelial height and duct luminal area. These increases by TE were reduced after treatment with Red Maca for 42 days. Histology pictures in rats treated with Red Maca plus TE were similar to controls. Phytochemical screening showed that aqueous extract of Red Maca has alkaloids, steroids, tannins, saponins, and cardiotonic glycosides. The IR spectra of the three ecotypes of Maca in 3800-650 cm (-1 region had 7 peaks representing 7 functional chemical groups. Highest peak values were observed for Red Maca, intermediate values for Yellow Maca and low values for Black Maca. These functional groups correspond among others to benzyl glucosinolate. Conclusions Red Maca, a cruciferous plant from the highland of Peru, reduced ventral prostate size in normal and TE treated rats.

  15. Population and Environment

    OpenAIRE

    Theodore Panayotou

    2000-01-01

    The past fifty years have witnessed two simultaneous and accelerating trends: an explosive growth in population and a steep increase in resource depletion and environmental degradation. These trends have fueled the debate on the link between population and environment that began 150 years earlier, when Malthus voiced his concern about the ability of the earth and its finite resources to feed an exponentially growing population. The purpose of this study is to review the literature on populati...

  16. Measurably evolving populations

    DEFF Research Database (Denmark)

    Drummond, Alexei James; Pybus, Oliver George; Rambaut, Andrew

    2003-01-01

    processes through time. Populations for which such studies are possible � measurably evolving populations (MEPs) � are characterized by sufficiently long or numerous sampled sequences and a fast mutation rate relative to the available range of sequence sampling times. The impact of sequences sampled through...... time has been most apparent in the disciplines of RNA viral evolution and ancient DNA, where they enable us to estimate divergence times without paleontological calibrations, and to analyze temporal changes in population size, population structure and substitution rates. Thus, MEPs could increase our...

  17. Population and development.

    Science.gov (United States)

    1999-04-01

    This article highlights improvements in China's population development, particularly in its family planning programs. China first realized the importance of family planning in 1962. 2 years later, a Family Planning Office was established under the State Council, which was upgraded into a Leading Group in 1973, and population began to be incorporated into national planning. In 1981, the State Family Planning Commission was established as a ministry-level organization directly under the State Council. In 1982, the government further defined its population policy as "controlling population growth and improving population quality.¿ Moreover, in the wake of the International Conference on Population Development in 1994 and the Fourth World Conference on Women in 1995, China has called for reorientations in family planning programs and in social regulations. This article also presents the efforts of the Chinese government to protect the country's environment and the employment of certain measures to facilitate population migration in response to the needs of the migrant population for family planning and health care.

  18. The Population Activist's Handbook.

    Science.gov (United States)

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  19. The World Population Dilemma.

    Science.gov (United States)

    Population Reference Bureau, Inc., Washington, DC.

    This book is the third in a series published by the Population Reference Bureau aimed at illuminating the facts and consequences of human population dynamics for secondary and college-age students. Many illustrations, charts and graphs are included in this volume to help the reader grasp a number of the current ideas and concepts that are used in…

  20. Glaucoma in Asian Populations

    Science.gov (United States)

    ... is expected to become an even more serious problem as the world population and longevity increases. The other major glaucoma type ... of all cases of blindness from glaucoma in China. There is great racial diversity among Asian populations, and these differences are represented in the presentation ...

  1. Population. Headline Series.

    Science.gov (United States)

    Oppenheimer, Valerie K.

    Useful as background reading or secondary classroom material, this pamphlet reviews several dimensions of world population growth and control. The first of seven chapters, World Population Growth: Past, Present and Future, discusses some of the reasons for the greatly accelerated growth since 1950, and points out that even significantly rapid…

  2. Regional Population Dynamics

    Science.gov (United States)

    Andrew Birt

    2011-01-01

    The population dynamics of the southern pine beetle (SPB) exhibit characteristic fluctuations between relatively long endemic and shorter outbreak periods. Populations exhibit complex and hierarchical spatial structure with beetles and larvae aggregating within individual trees, infestations with multiple infested trees, and regional outbreaks that comprise a large...

  3. Negative Drift in Populations

    DEFF Research Database (Denmark)

    Lehre, Per Kristian

    2011-01-01

    An important step in gaining a better understanding of the stochastic dynamics of evolving populations, is the development of appropriate analytical tools. We present a new drift theorem for populations that allows properties of their long-term behaviour, e.g. the runtime of evolutionary algorithms...

  4. Population Studies of Tidal Marsh Breeding Birds at Rush Ranch: A Synthesis

    OpenAIRE

    Spautz, Hildie; Liu, Leonard; Estrella, Sarah; Nur, Nadav

    2012-01-01

    Rush Ranch, with the largest contiguous area of fully-tidal marsh remaining in northern Suisun Bay, is critical habitat for a number of endemic bird species that breed in brackish tidal marsh. Despite the abundance of non-native invasive plants (particularly perennial pepperweed, Lepidium latifolium) and altered hydrology, it is the best remaining representative in Solano County of the tidal marsh that once covered more than 27,000 ha (67,000 acres) in Suisun Bay. This paper presents a synthe...

  5. Stockholm sidesteps population issue.

    Science.gov (United States)

    1972-08-01

    Population policies were discussed during a U.N. Conference on the Human Environment held in Stockholm in June 1972. Although it was acknowledged that people in developed countries have a much more detrimental impact on the environment due to their high levels of consumption, various positions were taken on the importance of family planning in developing countries. Both the Chinese delegate and Indira Ghandi of India remarked that one cannot blame overpopulation for ecological problems. Other speakers agreed that technology would solve ecological problems and that population growth rates would take care of themselves when development occurred. Other speakers, such as Dr. Paul Ehrlich believe that worldwide stabilization of population is necessary to maintain life-support systems of this planet. The majority of delegates to the Conference did not consider the reduction of population growth to be a priority, although it was recommended that national governments develop population policies, and that WHO give increased support to family planning activities. It was also recommended that adequate attention be given to the relationship between population and environment at the World Population Conference in 1974.

  6. The population threat.

    Science.gov (United States)

    Teitelbaum, M S

    1992-01-01

    Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

  7. Predation and caribou populations

    Directory of Open Access Journals (Sweden)

    Dale R. Seip

    1991-10-01

    Full Text Available Predation, especially wolf (Canis lupus predation, limits many North American caribou (Rangifer tarandus populations below the density that food resources could sustain. The impact of predation depends on the parameters for the functional and numerical response of the wolves, relative to the potential annual increment of the caribou population. Differences in predator-avoidance strategies largely explain the major differences in caribou densities that occur naturally in North America. Caribou migrations that spatially separate caribou from wolves allow relatively high densities of caribou to survive. Non-migratory caribou that live in areas where wolf populations are sustained by alternate prey can be eliminated by wolf predation.

  8. Immunization in special populations.

    Science.gov (United States)

    Miller, Michael A; Rathore, Mobeen H

    2012-01-01

    In summary, immunizations in special populations require understanding the underlying disease and how it might affect the immune system's ability to mount an antibody response to vaccines or predispose certain patient populations to developing certain serious infections. There is still a great need for research on the optimal timing of vaccines after transplants, how to assess protection and development of a protective antibody response after immunization, and whether certain groups (eg, HIV) need to be revaccinated after a certain amount of time if their antibody levels decline. In addition, there are limited data on efficacy of the newer vaccines in these special patient populations, which also requires further investigation.

  9. Populated Places of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage contains points that represent populated places, ie. cities, towns, villages or any other named place where people live. The coverage was developed...

  10. Parallel grid population

    Science.gov (United States)

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  11. Fish population dynamics

    National Research Council Canada - National Science Library

    Gulland, J. A

    1977-01-01

    This book describes how the dynamics of fish populations can be analysed in terms of the factors affecting their rates of growth, mortality and reproduction, with particular emphasis on the effects of fishing...

  12. County Population Vulnerability

    Data.gov (United States)

    City and County of Durham, North Carolina — This layer summarizes the social vulnerability index for populations within each county in the United States at scales 1:3m and below. It answers the question...

  13. Market Squid Population Dynamics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains population dynamics data on paralarvae, juvenile and adult market squid collected off California and the US Pacific Northwest. These data were...

  14. Food for tomorrow's population.

    Science.gov (United States)

    Hugo, G

    1983-06-01

    This discussion outlines and clarifies the dimensions of the world's current food-population balance and examines likely future changes in this balance over the next 20 years. The 1st section summarizes the contemporary world demographic situation in the early 1980s, focusing on regional differences in patterns of population growth and the significant food shortages in the developing countries. A subsequent section considers the outlook for population growth up to the year 2000 with particular reference to the most recent UN population projects. The discussion of food production and supply includes some specific comments on the situation in Indonesia. The world's population in 1983 has been estimated at 4677 million. It will reach 5 billion in the next 5 years. The countries which can least afford it are growing the fastest. These countries will account for 79% of the world's population in 2000 and 83% by 2020. Fertility in the less developed countries (LDCs) is twice that of more developed countries, with women in the former group having an average of around 4.5 children and in the latter, 1.9. The substantial declines in fertility in many countries are not fully reflected in declines in population growth and natural increase rates. This is because of major improvements which have occurred in mortality. During recent decades there has been a marked increase in world food production. In the developed countries increases in food production have continued at more than twice those for population, but this was not the case in the less developed countries where the margin narrowed during the 1950s and 1960s until in the early 1970s population was increasing at a slightly faster rate overall than was food production. Food crisis situations continue to occur with disturbing frequency in several regions. Seasonal, regional, and national variations in food shortages are not the only dimensions to food-population imbalances. Within nations there is inequality in access to

  15. EDUCATION AND ROMA POPULATION

    Directory of Open Access Journals (Sweden)

    Ana Asensio Belenguer

    2016-07-01

    Full Text Available This article deals with Education and the Roma Population. It presents an approach to schooling of Romani children since its outset in the city of Zaragoza (Spain. It analyzes the current status as presented by the Strategy for Social Inclusion of this people 2012-2020, and collects, from various sources, the fact that education remains a pending challenge for Roma Population. Measures to be taken by the educational community from a gender and inclusive perspective are proposed.

  16. Population Density Modeling Tool

    Science.gov (United States)

    2012-06-26

    194 POPULATION DENSITY MODELING TOOL by Davy Andrew Michael Knott David Burke 26 June 2012 Distribution...MARYLAND NAWCADPAX/TR-2012/194 26 June 2012 POPULATION DENSITY MODELING TOOL by Davy Andrew Michael Knott David Burke...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE 26

  17. The politics of population.

    Science.gov (United States)

    Wolfson, M

    1986-03-01

    This article suggests some of the principal factors behind the decisions by an increasing number of countries deciding that the achievement of their national objectives required a policy for population, and the way that they are likely to work out. By 1983, 35 developing countries had an official policy to reduce their population growth rate, and in 34 others, the government supported family planning activities--usually for reasons of health or as a human right. The number is remarkable given the many compelling reasons that governments have for not attempting anything so difficult as to modify demographic trends. The future results of population programs, in social and economic terms, are very difficult to quantify, thus defying cost-benefit analysis of the desirability of investing resources in this area, rather than in something else. There are also powerful political reasons why a government might well hesitate before embarking on a policy to reduce the nation's fertility. At the very least, it implies government interference in the most private and personal of human relations, an invasion of human rights, and a disturbance of the traditional patterns of society and behavior. For many countries that are pursuing a policy to limit population growth, the decision has been taken only after the grievous consequences of not having such a policy have already become manifest. The critical question is how soon a government will make the connection among political disobedience, economic and social distress, and the population explosion, and adopt a population policy. Although the number of developing countries that have officially proclaimed a strongly pro-natalist population policy is relatively small, many have Marxist governments. Overall, governments have several strategies at their disposal: 1) improving the accessability and the quality of the service; 2) promoting population education and family planning motivation (with the assistance of the media, folk art, and

  18. Rapid population growth.

    Science.gov (United States)

    1972-01-01

    At the current rate of population growth, world population by 2000 is expected to reach 7 billion or more, with developing countries accounting for some 5.4 billion, and economically advanced nations accounting for 1.6 billion. 'Population explosion' is the result of falling mortality rates and continuing high birth rates. Many European countries, and Japan, have already completed what is termed as demographic transition, that is, birth rates have fallen to below 20 births per 1000 population, death rates to 10/1000 population, and annual growth rates are 1% or less; annual growth rates for less developed countries ranged from 2 to 3.5%. Less developed countries can be divided into 3 groups: 1) countries with both high birth and death rates; 2) countries with high birth rates and low death rates; and 3) countries with intermediate and declining birth rates and low death rates. Rapid population growth has serious economic consequences. It encourages inequities in income distribution; it limits rate of growth of gross national product by holding down level of savings and capital investments; it exerts pressure on agricultural production and land; and it creates unemployment problems. In addition, the quality of education for increasing number of chidren is adversely affected, as high proportions of children reduce the amount that can be spent for the education of each child out of the educational budget; the cost and adequacy of health and welfare services are affected in a similar way. Other serious consequences of rapid population growth are maternal death and illness, and physical and mental retardation of children of very poor families. It is very urgent that over a billion births be prevented in the next 30 years to reduce annual population growth rate from the current 2% to 1% per year.

  19. Population: sources and trends.

    Science.gov (United States)

    Keane, J G

    1986-01-01

    Most of the data on US immigration flows do not come from the Census Bureau; rather, data from the Immigration and Naturalization Service, on the number of legal migrants entering the country, and from the Office of Refugee Resettlement on the number of refugees entering the country is used. Between 1970 and 1980, the foreign-born population in the US grew by some 4.5 million persons or an astounding 46%. The foreign-born population in the US is concentrated in a few geographic areas; 3.6 million, or 1/4 of the foreign-born, live in California, and New York and Florida together have another 1/4 of the foreign-born population. The concentration of the foreign-born population is very pronounced in metropolitan areas. Mexico supplied the largest fraction of the foreign-born population in the 1980 census. Over 5 out of every 6 or 84% of the foreign-born persons who came to the US before 1950 were born in Europe or Canada. The shift from Europe as the main source of immigration was marked by a shift to Latin America and Asia as the principal sources of recent migrants to the US. The Census Bureau has made a number of projections using different scenarios for fertility, mortality, and immigration. The middle migration series, roughly consistent with current levels of legal immigration, shows that the population would grow to about 311 million by 2080 from a current level of 237 million.

  20. Vietnam's population: current notes.

    Science.gov (United States)

    Fraser, S E

    1984-06-01

    In an effort to curb the population growth rate, currently estimated at 2.5%/year, the government of Vietnam has stepped up its campaign to implement a national family planning program. 1979 census figures indicate a population of 52.76 million. There is increasing government awareness of the interaction between population growth, employment, and manpower utilization. The demographic realities of Vietnam necessitate a drastic decrease in fertility rates and family size, a redistribution of the population either through internal migration to new economic zones or transborder migration, and a more efficient use of land and exploitation of natural and human resources to support the growing population. Assuming a natural increase rate of less than 2% by 1984-85, the government estimates a total population of nearly 60 million by the end of 1985. It is hoped that a natural growth rate of 1% can be attained in the early 1990s, to achieve a population size below 75 million by the year 2000. However, if the 3-child family remains the norm, the population will approach 80-85 million by 2000. Changes in shortterm fertility patterns seem unlikely without a carefully thought out and sensitively implemented policy involving a deliberate scheme of incentives and disincentives. The Vietnam Fatherland Front (VFF) has recognized the need for a more regorous fertility control campaign and has requested that the Council of Ministers set up a coordinated population and family planning structure with direct linkages from Hanoi to provincial governments and communal administrations. Also recommended were regulations on birth control, population targets and norms, and a system of incentives and disincentives. Data from family planning services in Ho Chi Minh City for 1976-82 suggest a recent decline in IUD, condom, and pill users, largely as a result of procurement difficulties. The number of abortions has also declined because of successful family planning education. The ideal family

  1. Population and the environment.

    Science.gov (United States)

    1987-01-01

    The pressures created by increasing number of people and increasing migration have aggravated environmental and resource problems in many developing countries. To deal with these problems, there is a need to formulate mutually supportive population and environmental policies. Especially in developing countries, where most of the world's population growth will occur and where there will be the greatest growth in urban centers. Efforts to promote development in a way that preserves the resource base for future generations will have to take into account demographic factors, since excessive population pressure in specific geographical areas can pose serious ecological hazards, including soil erosion, desertification, dwindling firewood supplies, deforestation, and the degradation of fresh water sources. Often the link between population pressure and those types of environmental stress is the growth in the relative and absolute number of persons living in poverty. The result is marginalization of small-scale farmers and pressure on larger numbers to migrate from distressed areas, and increased prevalence of environmentally related diseases. Population policies should also be formulated with due regard for environmental factors, with priority in those geographical areas likely to experience acute environmental stress. Programs for influencing the distribution of population should also consider the environmental impact. Monitoring and forecasting of likely changes in the status of key natural resources should be communicated to communities to obtain grass-roots support. Ultimately, however, problems of population and the environment can only be resolved in the context of a comprehensive program at the national and international levels to promote economic and social development.

  2. Population and environment.

    Science.gov (United States)

    1997-04-01

    This article discusses the recent February 1997 Mainichi Newspaper symposium entitled "Securing the Safety of the Biosphere: The Population Explosion and the Global Environment," held in Tokyo, Japan. The symposium was a tribute to the commitment of the newspaper company to global population and environmental issues. Dr. Fred Sai, past president of IPPF, was a guest speaker. Both Dr. Sai and the Mainichi were honored in 1993 with the UN Population Award. A symposium outcome was the "Tokyo Declaration." The declaration was developed by the 21st Century Environmental Crisis Warning Committee under the direction of the Mainichi Newspapers and by international experts. The declaration called for appropriate population policies, respect for women's full participation in society, gender equality, the rights of women to determine their own sexual and reproductive health, and the rights of children to a healthy mind and body. Other speakers included the executive coordinator of United National Reform, the chairman of the Earth Council, the chairman of the Intergovernmental Panel on Climatic Change, the president of the World Watch Institute, and the chairman of the Swaminathan Research Foundation. The director of the Study and Research Division of JOICFP spoke about including women's views into discussions about population and the environment. Women were credited with playing an important population control role at the grassroots level. It was argued that population is reduced best by meeting the unmet needs of women and providing reproductive health services. Women and couples should be guaranteed informed choice. The issue of abortion availability should not be based on religious or social values.

  3. The population of Brazil

    Directory of Open Access Journals (Sweden)

    João Yunes

    1972-12-01

    Full Text Available In 1970 the population of Brazil with 94,508,554 inhabitants was extreme youth, since 42.67% was composed of children under 14 years old. In that year the proportion of female was 50.2%. The population density increased from 1.17 inhabitants /km² in 1872 to 11.18 in 1970, and in this last year the range was 1.03 in the North region and 43.90 in the South-East region. The urban population increased from 31.24% in 1940 to 55.98% in 1970 and for the first time the rural population was smaller than the urban population. In 1950 concerning with marital status 39% of the population 15 years old and over was single and 54% married. In 1970 this rate was respectively 35.4% and 56.6%. The population economically inactive increased from 49.17% in 1940 to 52.24% in 1970. The literacy ratio increased from 43% in 1940, to 48% in 1950 and 68.04% in 1970. The crude birth rate was 43/1000 live births in 1950 and fell to 37.7/1000 in 1970. The fertility rate decreased from 179.3/1000 women (15-49 years old} to 156.7/1000 in 1960/70. The crude death rate decreased from 20.60/1000 inhabitants in 1940/50 to 9.4/1000 in 1960/70. The infant mortality rate still remains high: 171/1000 live births in 1940/50 and 170/1000 in 1971. Concerning with the size of the cities, 8 in 1940 had 100,000 or more inhabitants and in 1970 this number increased to 94 cities. The population growth increased from 2.38% in 1940/50, to 2.99% in 1950/60 and 2.83% in 1960./70. Brazil is the first country in population size in Latin America and the eighth in the world. Concerning his area, Brazil is the fifth country in size.

  4. Alternative population futures.

    Science.gov (United States)

    1980-01-01

    The Philippines is now passing through a late demographic transitional period in which the death rate declines while the birth rate remains at a relatively high level; the population of young people under 15 rises to about 45% of the population while proportions of people of working age and old people decline. In 1970, 4 of the Philippine's 12 regions had a birth rate exceeding 40/1000; life expectancy at birth in these regions ranged from 57-64 years and population growth rates ranged from 2.6-4.2% annually. Also in 1970 40-49% of all 12 regional populations were young (under 15) and only 2-5% were old. In this transitional period there are a greater number of children in each household and thus heavier social and economic burdens occur; also the burden of youth dependency increases by more than 1/3. In the modern population structure, family burdens diminish as the average number of children surviving to age 20 becomes identical with the number of children born and great improvements in the quality of life are allowed. Population projections are based on the following assumptions: 1) decrease in mortality, either rapid or slow, 2) increase in age at marriage, 3) decline in fertility will remain at 0.7% annually, and 4) migration trends will stay the same as during the 1960-75 period. Total population is expected to reach 83.8 million by 2000, a 98% increase from 1975; a low estimate, assuming lower fertility and nuptiality, is 64.1 million, a 52% increase from 1975. The urban population will more than double its size by the year 2000 and rural population will grow from 22-65% with the fastest urbanizing regions being the Central and Southern Luzon. From 1975-2000 a 3-fold increase is expected in the number of families in Metro Manila. By 2000 a national labor force of 27.5 million is expected, more than double the 1970 level, with late entry into the labor force and declines in participation by elderly males. The various regions will see lower economic activity

  5. Population explosion, social change.

    Science.gov (United States)

    Pethe, V P

    1983-01-26

    The issue of whether overpopulation is the cause of poverty or vice versa is a sham controversy. Both population explosion and poverty are symptoms of a deeper problem, i.e., the incapacity of the socioeconomic system and the international economic order to put into service modern science and technology for an optimal utilization of this planet's vast resources for economic development. There is no question that population growth cannot be allowed to go unabated for an indefinite period, yet there is no reason for alarm. History shows that human adjustments in social behavior have always restored equilibria in every crisis in the progress of humankind. Neo-Malthusians fail to see this point. Instead, they try to create a scare by making unrealistic projections. There is no need for the incorrect and dangerous neo-Malthusian theory as a way to plead for checking population growth. There are 3 simple reasons why population growth should slow down: populations in most less developed countries have a size sufficiently large to make them militarily and economically viable and will not face serious problems in economic and social management if their populations get stabilized at the current levels; there are several advantages in changing attitudes and behavior patterns in respect to matters such as marriage age, family limitation, and spacing of children, and these are desirable in their own right besides their effect on reducing fertility and population growth; and a need exists to intervene on the side of fertility in order to maintain the longrun equilibrium of population size. In the past, equilibrium between mortality and fertility was achieved through the operation of natural factors. Now, with the reduction in mortality as a result of human intervention, it has become necessary to bring about a decline in fertility through human intervention. Human intervention in the control of fertility is a difficult and complex process. The solution to the population

  6. Mexico's population: a profile.

    Science.gov (United States)

    Paul, N

    1987-05-01

    Mexico's population is estimated at 82 million in 1987, making it the 2nd most populous country of Latin America after Brazil. This demographic explosion is a classic example of what occurs when modern technology is suddenly infused into a traditional society: death rates decline rapidly due to improved health care and better living standards, while the birth rate remains high. In 1973, the pronatalist law on population dating from 1947 was drastically revised, signalling the start of a series of direct and indirect measures to reduce population growth. Today, slow economic growth and capital scarcity make it difficult to create new industries that might provide some employment. Mexican workers have been migrating to the US since the 1800s, but more are entering the US now than ever before. Rural-to-urban migration in Mexico is creating a drop in food production and putting severe strains on city housing, school systems, transportation, and medical facilities. The new immigration law introduced by the US Congress adds a new dimension to Mexico's future; Mexicans fear that the return of 1000s of workers will have severe repercussions on their economy, as the numbers of unemployed will increase. Overall, strong structural changes, close to the root of the problem, are needed. In this case, a revival of the Mexican economy, using a determined population policy is 1 strategy.

  7. Population and development.

    Science.gov (United States)

    Ramana, D V

    1977-10-01

    Between 1950-1976 world population increased by 1.5 billion and was accompanied by unprecedented levels of poverty, unemployment, and inequality. Additional problems associated with this marked population increase are related to food supply, human resource development, the infrastructure component of human organization - housing, water supply, and lighting - and environment. Consequently, it becomes apparent that for purposes of development over the next generation or so, it is the absolute population size and its built-in momentum for increase that becomes relevant rather than the declaration of the population growth rate. Necessary is a model of development in which both consumption and investment expenditures are planned in such a way as to yield the highest possible social rate of return. Investment and consumption planning is required as instrumentalities for making income accrue directly to as great a section of the poor as possible. Simultaneously, the following action should be initiated for decreasing the fertility rate to replacement levels: provision of family planning services, education of all social groups regarding the effects of large families and rapid population growth, provision of alternative careers to motherhood, equal rights for women, and reshaping economic and social policies to encourage small families.

  8. Intrinsically dynamic population models

    Directory of Open Access Journals (Sweden)

    Robert Schoen

    2005-03-01

    Full Text Available Intrinsically dynamic models (IDMs depict populations whose cumulative growth rate over a number of intervals equals the product of the long term growth rates (that is the dominant roots or dominant eigenvalues associated with each of those intervals. Here the focus is on the birth trajectory produced by a sequence of population projection (Leslie matrices. The elements of a Leslie matrix are represented as straightforward functions of the roots of the matrix, and new relationships are presented linking the roots of a matrix to its Net Reproduction Rate and stable mean age of childbearing. Incorporating mortality changes in the rates of reproduction yields an IDM when the subordinate roots are held constant over time. In IDMs, the birth trajectory generated by any specified sequence of Leslie matrices can be found analytically. In the Leslie model with 15 year age groups, the constant subordinate root assumption leads to reasonable changes in the age pattern of fertility, and equations (27 and (30 provide the population size and structure that result from changing levels of net reproduction. IDMs generalize the fixed rate stable population model. They can characterize any observed population, and can provide new insights into dynamic demographic behavior, including the momentum associated with gradual or irregular paths to zero growth.

  9. World population in transition.

    Science.gov (United States)

    Merrick, T W

    1986-04-01

    The world's population growth rate peaked at slightly over 2%/year in the late 1960s and in 1986 is down to 1.7% and falling. Annual numbers added continue to rise because these rates apply to a very large base, 4.9 billion in 1986. According to UN medium variant projections, world population growth will peak at 89 million/year in the late 1990s and then taper off until world population stabilizes in the late decade of the 21st century at about 10.2 billion. Close to 95% of this growth is occurring in less developed countries (LDCs) of Africa, Asia (minus Japan), and Latin America. LDC fertility rates are declining, except in sub-Saharan Africa and parts of Latin America and South Asia, but most have far to go to reach the replacement level of 2.1 births/woman. Fertility is below replacement in virtually all more developed countries. For LDCs, large numbers will be added before stabilization even after attainment of replacement level fertility because of the demographic momentum built into their large and young population bases. This complicates efforts to bridge gaps between living standards in LDCs and industrialized countries. From a new debate about whether rapid population growth deters or stimulates economic growth, a more integrated view has emerged. This view recognizes the complementary relationship between efforts to slow population growth and other development efforts; e.g., to improve health and education, upgrade women's status, increase productivity. Most effective in the increased contraceptive prevalence and fertility declines seen in many LDCs has been the combination of organized programs to increase access to family planning information and supplies with socioeconomic development that enhances the desire for smaller families.

  10. [Population problem, comprehension problem].

    Science.gov (United States)

    Tallon, F

    1993-08-01

    Overpopulation of developing countries in general, and Rwanda in particular, is not just their problem but a problem for developed countries as well. Rapid population growth is a key factor in the increase of poverty in sub-Saharan Africa. Population growth outstrips food production. Africa receives more and more foreign food, economic, and family planning aid each year. The Government of Rwanda encourages reduced population growth. Some people criticize it, but this criticism results in mortality and suffering. One must combat this ignorance, but attitudes change slowly. Some of these same people find the government's acceptance of family planning an invasion of their privacy. Others complain that rich countries do not have campaigns to reduce births, so why should Rwanda do so? The rate of schooling does not increase in Africa, even though the number of children in school increases, because of rapid population growth. Education is key to improvements in Africa's socioeconomic growth. Thus, Africa, is underpopulated in terms of potentiality but overpopulated in terms of reality, current conditions, and possibilities of overexploitation. Africa needs to invest in human resources. Families need to save, and to so, they must refrain from having many children. Africa should resist the temptation to waste, as rich countries do, and denounce it. Africa needs to become more independent of these countries, but structural adjustment plans, growing debt, and rapid population growth limit national independence. Food aid is a means for developed countries to dominate developing countries. Modernization through foreign aid has had some positive effects on developing countries (e.g., improved hygiene, mortality reduction), but these also sparked rapid population growth. Rwandan society is no longer traditional, but it is also not yet modern. A change in mentality to fewer births, better quality of life for living infants, better education, and less burden for women must occur

  11. Population vs. the environment.

    Science.gov (United States)

    1992-03-01

    In anticipation of UN Conference on Environment and Development scheduled for June in Brazil, the Japan Broadcasting Corporation (NHK) recently televised a hard-hitting documentary focusing on the impact of rapid population growth on resources and the environment. Entitled "Population Explosion and the Looming Crisis: Can Humankind Determine a Better Future?" the documentary aired on January 5, featuring interviews with experts from the population field such as Dr. Nafis Sadik of the UNFPA and Dr. Paul Ehrlich of Stanford University. The program, made with the cooperation of UNFPA and JOICFP, compared the current global demograhic and environmental situation with the one expected to exist in 2025, when the world population is expected to reach 10 billion. The documentary depicted a future fraught with food shortages, depleted energe resources, refugees, and a devastated environment. In order to illustrate the effect of population growth in developing countries, the documentary featured reports from countries in Asia and Africa. And to show the heavy burden that industrialized countries place on the global environment, the documentary examined Japan's own pattern of consumption and waste. As the UNFPA's Sadik pointed out, the luxurious lifestyle of developed countries comes at the expense of the developing world. Stressing that everyone in the world should be able to enjoy a reasonable standard of living. Sadik called for "sustainable patterns of development," which can be achieved through the following: improved technology, reduced consumption patterns, and changed lifestyles. A critical element in changing lifestyles includes reducing global fertility to 3.2 children/woman by the year 2000. Otherwise, a world population will not double but triple by the year 2025.

  12. Befolkningsudviklingen (Population Development)

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    2010-01-01

    The article takes the 1972 report, The Limits to Growth as its starting point, briefly explaining the Systam Dynamics model used for the report's analyses. Focus is on the important role of population. The simple model of I = PxAxT, where I is the environmental Impact, P population......, A is the Affluence and T the ecoimpact-intensity of the Technology used. Various scenarios ar shown, illustrating how a choice of 1.6 birth per woman on average instead of 2.6 birth, will in 2150 result in 3.6 billion people on earth instead of 27 billions. The article warns against the believe that growth in GDP...

  13. Africa population dynamics

    OpenAIRE

    Akinyoade, A.; Damen, J.C.M.; Dietz, A.J.; Kilama, B.B.; Omme, van, G.

    2014-01-01

    Africa's population has grown extremely rapidly over the last fifty years from 289 million inhabitants in 1961 to more than 1 billion today. This is a growth rate of 350% in just half a century and the number of urban residents has increased even more quickly: from 65 million in 1960 to 460 million today, or from 20% to 46% of the population as a whole. Demographers predict that soon more than 50% of all Africans will be living in cities. The average life expectancy, literacy rates and primar...

  14. Having quality population.

    Science.gov (United States)

    Ramos, F V

    1993-06-01

    This speech was delivered during Population and Development Week in the Philippines. Attention was drawn to population statistics: an annual growth rate of 2.3%, density of 202 persons/sq km, and an expected population of 75 million by the year 2000. Coupled with rapid population growth is the uneven distribution of wealth: the top 20% have over 50% of the total income and the lowest 20% have only 5% of the income. In such a social situation, it is women and children who are the most vulnerable. In cities, unemployment is high due to population growth and the migration of the rural poor. The rural poor living in areas of declining resources also move onto marginal uplands, which adds pressure to the already fragile ecology. Everyone must accept that the nation's problems are due to overpopulation. The government's development plans aim for sustainable growth, poverty alleviation, reduction in equality, generation of job opportunities, and achievement of social justice. People in government are determined to lead the Philippines toward a higher standard comparable with other dynamic Asian neighbors. The strategy is empowerment of the people. THe value is in the welfare of individuals and their families and the welfare of the nation. Couples have the right to manage their family size voluntarily and responsibly. The government's role is to provide adequate information on family planning in accordance with individual's religious convictions. Policies will also be directed to improved access to quality education, child survival, and maternal health, employment opportunities, and access and control over resources for people. There must be fuller participation of women in development. Support for the government's population program is sought from government officials, the private sector, and nongovernmental organizations. All provincial governors, city and municipal mayors, and all local executives will be directed to formulate population plans and to provide family

  15. Constructing populations in biobanking

    DEFF Research Database (Denmark)

    Tupasela, Aaro; Snell, Karoliina; Cañada, Jose a.

    2015-01-01

    This article poses the question of whether biobanking practices and standards are giving rise to the construction of populations from which various biobanking initiatives increasingly draw on for legitimacy? We argue that although recent biobanking policies encourage various forms of engagement w...

  16. Population and Development Issues.

    Science.gov (United States)

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  17. Population: fiction and fact.

    Science.gov (United States)

    1979-09-01

    This article was written to refute some common misunderstandings regarding worldwide population levels and worldwide nutrition levels. The world food supply is able to keep pace with high population growth levels. Worl food production currently meets world need; the problem is a distribution system which allocates food only to those who can pay rather than to those who need it. In many developing countries, the best agricultural lands are reserved for commercial crops rather than for subsistence crops. The U.S. food aid program does not help the most needy nations generally. The rate of world population growth is already slowing down. The desire for large families in developing countries is very often a realistic reaction to the prevailing economic system. Family planning programs will succeed. They will succeed even better in countries where general development planning is undertaken concurrently with family planning. Environmental problems are attributable to the consumption explosion in the rich countries rather than to the population explosion in the poor countries.

  18. Population, food and knowledge

    DEFF Research Database (Denmark)

    Strulik, Holger; Weisdorf, Jacob Louis

    2008-01-01

    of population. London, printed for J. Johnson, 1798) so-called preventive check hypothesis-that fertility rates vary inversely with the price of food-the current study offers a new and straightforward explanation for the demographic transition and the break with the Malthusian era. Employing a two...

  19. [Population trends and poverty].

    Science.gov (United States)

    Olmedo, C

    1998-04-01

    Implications of population growth in Ecuador for the quality of life of the poor population are analyzed. It is argued that if the gross national product (GNP) were to grow at a sustained annual rate of 5% or more, demographic trends would not present a significant obstacle to reducing poverty. National economic projections are for growth of only 2.5-3.5% annually. The continuing rapid growth of the poor population despite general slowing of demographic growth, the young age structure, the need for increased formal education to enable the poor to overcome their poverty, and the effect of unemployment on the dependency ratio will tend to hamper improvements in average productivity and per capita GNP. The need for spending on education, health, basic services, and housing will divert funds away from productive investment, generating a direct negative impact on economic growth. Over half of Ecuadorian children suffer from some degree of malnutrition, indicating that food production is inadequate to meet demand. The export-oriented agricultural policy and poor weather have led to a chronic shortage of basic foods. Progressive increase and diversification of agricultural production, along with maintenance of low prices and substantial increases in income levels and agricultural productivity, will be required if the entire population is to be fed adequately. Intense efforts will be needed from all sectors to bring demographic growth into balance with economic and development needs.

  20. (Hyperolius marmoratus) populations

    African Journals Online (AJOL)

    population differentiation among ..... 13: 121-177. RICHARDS. C.M. & MOORE. W.S. 1996. A phylogeny for the. African tree frog family Ilyperoliidne based on mitochondrial. rONA. Mol. Phyl. Evol. 5(3): 522-532. SELANDER. R.K. & KAlJFMAN.

  1. [Population and development].

    Science.gov (United States)

    Trias, M

    1987-01-01

    Human reproduction and development are contrasted; they are intimately linked despite the fact that they may be considered antitheses of each other from many points of view. Presently technological development and the advance of humans into every available corner of living space threaten to place the whole world environment in danger. The Green revolution of the 1960s addressed problems of underproduction of food for the world's population, without providing for the effective distribution of the new surpluses, and without addressing the problem of the ecological impact. 2 trends which are regarded by some with alarm: the migration of populations to the cities and the aging of the population with the connected burden on health care systems, are inevitable, and it is not clear that they are completely negative trends. Addressing these issues will have positive effects in the long run: congestion in the cities, the result of mechanization of rural industry which also results in a greater abundance of agricultural products necessary to society, should force serious consideration of problems such as solid waste management. Coming to terms with the costs of intervention to save lives among the very frail elderly and the prematurely born will have the effect of bringing controversial topics such as euthenasia and eugenics to discussion. The important role played by economic development in the braking of population expansion is underlined.

  2. Africa population dynamics

    NARCIS (Netherlands)

    Akinyoade, A.; Damen, J.C.M.; Dietz, A.J.; Kilama, B.B.; Omme, van G.

    2014-01-01

    Africa's population has grown extremely rapidly over the last fifty years from 289 million inhabitants in 1961 to more than 1 billion today. This is a growth rate of 350% in just half a century and the number of urban residents has increased even more quickly: from 65 million in 1960 to 460 million

  3. Ideology and population theory.

    Science.gov (United States)

    Harvey, D

    1974-01-01

    The ideological and ethical foundations of population theory are examined in the light of the supposed eithical neutrality of scientific enquiry. The works of Malthus, Ricardo, and Marx are contrasted and it is shown that their theories of population resulted in each case from the adoption of a particular kind of method--empiricism in Malthus, normative analytic "model building" in Ricardo, and dialectical materialism in Marx. It is shown that a Malthusian or neo-Malthusian view of the population problem is inevitable if enquiry is founded in empiricism or in normative analytics. The well-known disagreement between Malthusian and Marxian viewpoints therefore has its foundation in method. Most modern enquiry into the population-resources problem is dominated by empirical and analytic (including systems theory) approaches and consequently arrives at neo-Malthusian conclusions. The final section analyses the consequences of adopting a neo-Malthusian view, and it is shown that in a world dominated by an elite, this can frequently bring about the political, social, and economic repression of a non-elite. It is concluded that the choice of scientific method does not produce unbiased results and that the dominance of a certain conception of scientific method leads to the scientific support of a viewpoint used to justify repression of the underprivileged in society.

  4. Probabilistic population aging.

    Science.gov (United States)

    Sanderson, Warren C; Scherbov, Sergei; Gerland, Patrick

    2017-01-01

    We merge two methodologies, prospective measures of population aging and probabilistic population forecasts. We compare the speed of change and variability in forecasts of the old age dependency ratio and the prospective old age dependency ratio as well as the same comparison for the median age and the prospective median age. While conventional measures of population aging are computed on the basis of the number of years people have already lived, prospective measures are computed also taking account of the expected number of years they have left to live. Those remaining life expectancies change over time and differ from place to place. We compare the probabilistic distributions of the conventional and prospective measures using examples from China, Germany, Iran, and the United States. The changes over time and the variability of the prospective indicators are smaller than those that are observed in the conventional ones. A wide variety of new results emerge from the combination of methodologies. For example, for Germany, Iran, and the United States the likelihood that the prospective median age of the population in 2098 will be lower than it is today is close to 100 percent.

  5. Effect of unsampled populations on the estimation of population sizes and migration rates between sampled populations.

    Science.gov (United States)

    Beerli, Peter

    2004-04-01

    Current estimators of gene flow come in two methods; those that estimate parameters assuming that the populations investigated are a small random sample of a large number of populations and those that assume that all populations were sampled. Maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes directly using coalescent theory can easily accommodate datasets that contain a population that has no data, a so-called 'ghost' population. This manipulation allows us to explore the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The effects on the population sizes are larger than the effects on the migration rates. The more immigrants from the unknown populations that are arriving in the sample populations the larger the estimated population sizes. Taking into account a ghost population improves or at least does not harm the estimation of population sizes. Estimates of the scaled migration rate M (migration rate per generation divided by the mutation rate per generation) are fairly robust as long as migration rates from the unknown populations are not huge. The inclusion of a ghost population does not improve the estimation of the migration rate M; when the migration rates are estimated as the number of immigrants Nm then a ghost population improves the estimates because of its effect on population size estimation. It seems that for 'real world' analyses one should carefully choose which populations to sample, but there is no need to sample every population in the neighbourhood of a population of interest.

  6. The population explodes.

    Science.gov (United States)

    Hickcox, S

    1999-01-01

    This letter to the editor refers to an article on the "Baby Boom" published in 1998. The letter notes that no consensus exists among environmentalists about population growth or abortion and calls for more balance in coverage of these issues. The letter points out that, in animal and human populations, a "natural" suppression of reproduction occurs in the presence of a stable ecosystem. However, humans have forever changed the delicate balance of earth's ecosystems. The letter offers China as an example of a country whose drive to become an industrialized power is causing overuse, neglect, and destruction of natural resources. The letter concludes that efforts to obtain sustainability should involve a "more sobering look at free enterprise and the global economy."

  7. On optimal population paths

    CERN Document Server

    Lane, John S

    1977-01-01

    The overall purpose of this monograph is to integrate and critically evaluate the existing literature in the area of optimal joint savings population programs. The existing diverse presentations are all seen to be discussions within a unified framework. The central problem is to compare the desirability of alternative inter-temporal sequences of total savings and population sizes. Of critical importance is whether one regards persons as the fundamental moral entities or whether one takes Sidgwick's viewpoint that something good being the result of one's action is the baSic reason for dOing anything. The latter viewpoint is consistent with defining a complete social preference ordering over these alternative sequences. Since part of one's interest is to evaluate the consequences of various ethical beliefs a com­ parative study of several such orderings is presented; in particular the Mill-Wolfe average utilitarian, and Sidgwick-Meade classical utilitarian) formulations. A possible problem with the social pref...

  8. Cancer among circumpolar populations

    DEFF Research Database (Denmark)

    Young, T Kue; Kelly, Janet J; Friborg, Jeppe

    2016-01-01

    OBJECTIVES: To determine and compare the incidence of cancer among the 8 Arctic States and their northern regions, with special focus on 3 cross-national indigenous groups--Inuit, Athabaskan Indians and Sami. METHODS: Data were extracted from national and regional statistical agencies and cancer...... registries, with direct age-standardization of rates to the world standard population. For comparison, the "world average" rates as reported in the GLOBOCAN database were used. FINDINGS: Age-standardized incidence rates by cancer sites were computed for the 8 Arctic States and 20 of their northern regions......, averaged over the decade 2000-2009. Cancer of the lung and colon/rectum in both sexes are the commonest in most populations. We combined the Inuit from Alaska, Northwest Territories, Nunavut and Greenland into a "Circumpolar Inuit" group and tracked cancer trends over four 5-year periods from 1989 to 2008...

  9. Populism and the media

    DEFF Research Database (Denmark)

    Esser, Frank; Stepinska, Agnieszka; Hopmann, David Nicolas

    2017-01-01

    /click” with a broad audience. As was stated in Chapter 1 in this volume, the role that the media play in the dissemination of populism is largely under-explored. In the classical research literature dealing with populism (see, e.g., Canovan, 1981; Taggart, 2000), communication and media are not addressed at all. When...... political scientists make the media their subject, they see the media mostly only as a neutral platform for populist leaders’ appearances and messages. One exception is Mudde (2007), who dedicates at least a few pages to this topic in his book Populist Radical Right Parties in Europe (pp. 248-253). He......European media systems have gone through major changes in the last few decades, and these changes have included increased opportunity structures for the dissemination of populist messages. Chapter 12 (‘Switzerland’) rightly states that the disappearance of the traditional party press, increased...

  10. [Population, ethics and equity].

    Science.gov (United States)

    Berlinguer, G

    1997-01-01

    "Demography is, explicitly and not, imbued with an [ethical] content.... As demography involves both public policies and individual choices, the [ethical] slant should be [examined]. Thus, what we have on the one hand is an [ethical] state, which dictates its citizens' personal behaviour and, on the other, a state based on liberty, backed up by three shared values: human rights, pluralism and equality. This article looks at how today these may be reinterpreted when making decisions regarding the population." (EXCERPT)

  11. Fertility and Population Policy

    OpenAIRE

    Ouedraogo, Abdoulaye; Tosun, Mehmet S.; Yang, Jingjing

    2018-01-01

    There have been significant changes in both the fertility rates and fertility perception since 1970s. In this paper, we examine the relationship between government policies towards fertility and the fertility trends. Total fertility rate, defined as the number of children per woman, is used as the main fertility trend variable. We use panel data from the United Nations World Population Policies database, and the World Bank World Development Indicators for the period 1976 through 2013. We find...

  12. Population, environment and development.

    Science.gov (United States)

    Karkal, M

    1994-06-01

    Western development models label subsistence economies, which do not participate in the market economy on a grand scale and do not consume commodities produced for and distributed through the market, to be poor. Yet, subsistence does not always indicate a low quality of life. The Western development process has destroyed wholesome and sustainable lifestyles. In India, the Green Revolution caused many small farmers to lose their land. In comparison to traditional economies, industrial economies have longer technological chains dependent on higher energy and resource inputs and exclude large numbers of people without power to buy goods. Further, they generate new and artificial needs, necessitating increased production of industrial goods and services. They erode resource bases for survival. This erosion is marginalizing people who were traditionally in nature's economy. Developed countries did not deliver 0.15% of their GNP to development projects in developing countries as promised. The US made population growth in these countries its cause. The UN and other multinational agencies during 1962-1972, at the US's request, began to support population and family planning programs in developing countries. These countries opposed the 1st draft at the 1974 Bucharest Population Conference, but by the conference in Mexico City, most supported the need for family planning. Yet, the US politicized this conference and had a greater say in the recommendations than did developing countries. Structural adjustments and external debt repayments required of developing countries in the 1980s set them back. In fact, the number of developing countries increased from 31 to 42. The UN recognizes the right to development, but social inequalities are barriers to this right. If environmental degradation continues, poverty will only increase. Women's groups are playing a great role in preparations for the International Conference on Population and Development in Cairo in September 1994.

  13. Globalisation, Inequality and Populism

    OpenAIRE

    Nolan, Brian

    2017-01-01

    read before the Society, 20 April 2017; Symposium 2016-2017: Globalisation, Inequality and the Rise of Populism Inequality in the distribution of income and wealth among individuals has now come to the fore as a core concern across the industrialised world. In 2013 then President of the United States Barack Obama identified rising income inequality as ?the defining challenge of our times?. The Managing Director of the International Monetary Fund Christine Lagarde has stated that ?reducing ...

  14. Population, desertification, and migration.

    Science.gov (United States)

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation.

  15. Target population growth: zero.

    Science.gov (United States)

    2000-02-01

    The Fifth Session of the Fourth National Council of the China Family Planning Association held in Beijing on December 13, 1999, focused on how to control the number of people in China and improve their quality of life. Family planners also explored ways to decrease the number of babies with birth defects and maternal mortality rate. During the meeting, Zhang Weiqing, minister of the State Family Planning Commission, expressed that they are optimistic about keeping the Chinese population under 1.3 billion before the 21st century. He added that top attention should be paid to providing family planning service (sexual and reproductive counseling) for unmarried young people, laid-off workers, and the transient population in urban areas. In Shenzhen, a special economic zone, 854 family planning offices have been established among 2.8 million temporary residents, these agencies, many of which are led by temporary residents themselves. Lastly, Zhang announced that a draft national law on population and family planning has been finished and the law is expected to be enacted in 3 years.

  16. Food and population.

    Science.gov (United States)

    1985-04-06

    Agricultural producttivity is currently characterized by the paradox of an abundace of food in the developed world and hunger in much of the developing world. In China, India, and many other countries of Asia, the general food supply has kept pace with population growth and should continue to if family planning programs gain momentum. In Africa, on the other hand, the food supply has been falling behind the growth of the population in the majority of countries for the past decade. The situation is especially serious in the Sahel, where the production wf crops for export has been prioritized over local needs. The Food and Agriculture Organization's global information and early warning system is a promising development and can provide alerts when weather or other conditions threaten a harvest. Donor countries can then send in cereals and other foods before there is an actual famine. About 20 disasters in the Sahel are etimated to have been averted by this system, in operation since 1975. In developed countries, the farming industry needs to be restructured in relation to changes in markets and technologies. Solution of the food-population problem depends upon agricultural policies that balance the economic interests of farmers and consumers and also takes into account the need to preserve the countryside.

  17. The population factor.

    Science.gov (United States)

    Kats, G

    1983-01-01

    Reducing population growth is essentil to Egypt's broader efforts to improve facilities, services, and the phsycial quality of life. Although a family planning program has existed since the mid-1950s, the 2.7% annual rate of population growth has not changed in 30 years. Nasser and the other "free officers" who seized power in 1952 became concerned about the adverse effects of the rapidly growing population, but perhaps out of concern with a possible religious backlash, they confined themselves to launching studies and subsidizing several dozen private family planning clinics. From 1962-72, the number of private clinics grew from 28 to 480, and family planning was introduced in government healthclinics in 1965. Such clinics are mainly located in rural areas and are staffed by doctors and other personnel who are not members of the local community and are not very effective at promoting family planning. Local girls and women called Rayadet were recruited to promote the idea to birth control in local communities. By 1970, 12.6% of Egyptians were using reliable contraception. A national survey 12 years later found 34% using contraception, buth the figure seems high. Approximately 60-65% of eligible couples would need to practice birth control for Egypt to reach a less than 1% annuel increase. The Egyptian government hopes to slow population growth to 1% by the year 2000, but major problems of motivation remain especially among the rural poor. Several factors may lead to success of the family planning effort: 1) financial and technical support from international family planning sources has grown rapidley and is likely to remain high; 2) the mortality rate has dropped from 17.8/1000 in 1952 to about half that level, while the rate of natural increase is about the same, suggesting that future reductions in the birth rate will translate to a reduced rate of natural increase, and that parents will be less reluctant to practice faimly planning if there is a greater chance

  18. Population and climate change.

    Science.gov (United States)

    Cohen, Joel E

    2010-06-01

    To review, the four broad dimensions of any complex human problem, including climate change, are the human population, economics, culture, and environment. These dimensions interact with one another in all directions and on many time-scales. From 2010 to 2050, the human population is likely to grow bigger, more slowly, older, and more urban. It is projected that by 2050 more than 2.6 billion people (almost 94% of global urban growth) will be added to the urban population in today's developing countries. That works out to 1.26 million additional urban people in today's developing countries every week from 2010 to 2050. Humans alter the climate by emitting greenhouse gases, by altering planetary albedo, and by altering atmospheric components. Between 1900 and 2000, humans' emissions of carbon into the atmosphere increased fifteenfold, while the numbers of people increased less than fourfold. Population growth alone, with constant rates of emissions per person, could not account for the increase in the carbon emissions to the atmosphere. The world economy grew sixteenfold in the twentieth century, accompanied by enormous increases in the burning of gas, oil, and coal. In the last quarter of the twentieth century, population grew much faster in developing countries than in high-income countries, and, compared with population growth, the growth of carbon emissions to the atmosphere was even faster in developing countries than in high-income countries. The ratio of emissions-to-population growth rates was 2.8 in developing countries compared with 1.6 in high-income countries. Emissions of CO2 and other greenhouse gases are influenced by the sizes and density of settlements, the sizes of households, and the ages of householders. Between 2010 and 2050, these demographic factors are anticipated to change substantially. Therefore demography will play a substantial role in the dynamics of climate changes. Climate changes affect many aspects of the living environment

  19. Population Growth and National Population Policy of India

    Science.gov (United States)

    Thukral, A. K.; Singh, B. P.

    2008-01-01

    The population growth in India may overtake China by the year 2030. The National Population Policy of India targets population stabilization in India by the year 2045. The present paper carries out objective analysis of the population growth in India in terms of change in specific growth. At the present rate of specific growth rate decline, the population by the end of the century will be 2.49 billion. For the population to achieve zero growth by the year 2045, a decline in specific growth rate will have to be achieved at the rate of 0.000428 per year.

  20. Population policies and development.

    Science.gov (United States)

    Stamper, B M

    1984-01-01

    This article critically examines 4 conceptual frameworks for Third World population policies: the family planning approach, beyond family planning measures, the development hypothesis and transition theory, and the distributive hypothesis and fertility. Although family planning is a basic human right and can lead to lower levels of population and improved maternal-child health, this approach alone does not always have a meaningful demographic impact. If high fertility is economically rational from the family viewpoint, the demand for family planning services will remain marginal. Other policies seek to go beyond the family planning approach and to directly influence the demand for reproductive control through provision of old age support, monetary incentives for reduced fertility or stringent and coercive measures. However, such policies can have adverse distributional effects and directly penalize the children of large families. The demographic transition theory lacks a measurable and specifiable causation mechanism, giving it little predictive value. It may be that economic growth increases fertility in the short run and reduces fertility only over the long run through indirect effects. The key issue is how the rate of growth is distributed across the population. The development and demographic transition hypothesis focuses mainly on aggregate economic and social measures rather than on their underlying distributions. The distributive hypothesis implies policies that promote a greater level of investment in human capital, with a wide distributional emphasis. Diffused investment in human capital is believed to indirectly influence the desire to control fertility. It is concluded that all 4 conceptual frameworks for analyzing fertility-related policies for the Third World are inadequate or seriously flawed. They are not pragmatic, do not identify or assign weights to the crucial causal variables, fail to specify thresholds or critical minimum levels, discount

  1. High population increase rates.

    Science.gov (United States)

    1991-09-01

    In addition to its economic and ethnic difficulties, the USSR faces several pressing demographic problems, including high population increase rates in several of its constituent republics. It has now become clear that although the country's rigid centralized planning succeeded in covering the basic needs of people, it did not lead to welfare growth. Since the 1970s, the Soviet economy has remained sluggish, which as led to increase in the death and birth rates. Furthermore, the ideology that held that demography could be entirely controlled by the country's political and economic system is contradicted by current Soviet reality, which shows that religion and ethnicity also play a significant role in demographic dynamics. Currently, Soviet republics fall under 2 categories--areas with high or low natural population increase rates. Republics with low rates consist of Christian populations (Armenia, Moldavia, Georgia, Byelorussia, Russia, Lithuania, Estonia, Latvia, Ukraine), while republics with high rates are Muslim (Tadzhikistan, Uzbekistan, Turkmenistan, Kirgizia, Azerbaijan Kazakhstan). The later group has natural increase rates as high as 3.3%. Although the USSR as a whole is not considered a developing country, the later group of republics fit the description of the UNFPA's priority list. Another serious demographic issue facing the USSR is its extremely high rate of abortion. This is especially true in the republics of low birth rates, where up to 60% of all pregnancies are terminated by induced abortions. Up to 1/5 of the USSR's annual health care budget is spent on clinical abortions -- money which could be better spent on the production of contraceptives. Along with the recent political and economic changes, the USSR is now eager to deal with its demographic problems.

  2. Hidden ion population: Revisited

    International Nuclear Information System (INIS)

    Olsen, R.C.; Chappell, C.R.; Gallagher, D.L.; Green, J.L.; Gurnett, D.A.

    1985-01-01

    Satellite potentials in the outer plasmasphere range from near zero to +5 to +10 V. Under such conditions ion measurements may not include the low energy core of the plasma population. In eclipse, the photoelectron current drops to zero, and the spacecraft potential can drop to near zero volts. In regions where the ambient plasma density is below 100 cm -3 , previously unobserved portions of the ambient plasma distribution function can become visible in eclipse. A survey of the data obtained from the retarding ion mass spectrometer (RIMS) on Dynamics Explorer 1 shows that the RIMS detector generally measured the isotropic background in both sunlight and eclipse in the plasma-sphere. Absolute density measurements for the ''hidden'' ion population are obtained for the first time using the plasma wave instrument observations of the upper hybrid resonance. Agreement in total density is found in sunlight and eclipse measurements at densities above 80 cm -3 . In eclipse, agreement is found at densities as low as 20 cm -3 . The isotropic plasma composition is primarily H + , with approx.10% He + , and 0.1 to 1.0% O + . A low energy field-aligned ion population appears in eclipse measurements outside the plasmasphere, which is obscured in sunlight. These field-aligned ions can be interpreted as field-aligned flows with densities of a few particles per cubic centimeter, flowing at 5-20 km/s. The problem in measuring these field-aligned flows in sunlight is the masking of the high energy tail of the field-aligned distribution by the isotropic background. Effective measurement of the core of the magnetospheric plasma distribution awaits satellites with active means of controlling the satellite potential

  3. Diabetes in population isolates

    DEFF Research Database (Denmark)

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders

    2015-01-01

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify...... on glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value...

  4. Playing With Population Protocols

    Directory of Open Access Journals (Sweden)

    Xavier Koegler

    2009-06-01

    Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.

  5. [Several problems concerning population investment].

    Science.gov (United States)

    Liu, Z

    1982-07-29

    Population investment is a major topic in the studies of population and economic relations. In this particular area, numerous theoretical and practical problems are still in need of solution. Concerning the problem of population concept, there are three different approaches: (1) to determine the definition of population investment from the relationship between the population growth and the capital from national income used for investment, including investment in the newly increased population and investment in the entire population; (2) to explain population investment from the economic viewpoint that people are producers; and (3) to explain population investment from the expense needed to change a simple labor force to a skillful labor force. The expenses include educational costs, maintanance spending, wages needed to compensate workers in labor, costs for workers to master and learn modern scientific techniques to be used for production, and the costs of keeping a young labor force in the next generation.

  6. Genetic changeover in Drosophila populations

    International Nuclear Information System (INIS)

    Wallace, B.

    1986-01-01

    Three populations of Drosophila melanogaster that were daughter populations of two others with histories of high, continuous radiation exposure [population 5 (irradiated, small population size) gave rise to populations 17 (small) and 18 (large); population 6 (irradiated, large population size) gave rise to population 19 (large)] were maintained for 1 year with no radiation exposure. The frequency with which random combinations of second chromosomes taken from population 19 proved to be lethal changed abruptly after about 8 months, thus revealing the origin of a selectively favored element in that population. (This element may or may not have been the cause of the lethality.) A comparison of the loss of lethals in populations 17 and 18 with a loss that occurred concurrently in the still-irradiated population 5 suggests that a second, selectively favored element had arisen in that population just before populations 17 and 18 were split off. This element was on a nonlethal chromosome. The result in population 5 was the elimination of many lethals from that population, followed by a subsequent increase as mutations occurred in the favored nonlethal chromosome. Populations 17 and 18, with no radiation exposure, underwent a loss of lethals with no subsequent increase. The events described here, as well as others to be described elsewhere, suggest that populations may be subject to episodic periods of rapid gene frequency changes that occur under intense selection pressure. In the instances in which the changeover was revealed by the elimination of preexisting lethals, earlier lethal frequencies were reduced by approximately one-half; the selectively favored elements appear, then, to be favored in the heterozygous--not homozygous--condition

  7. Population dynamics and biology of an invasive population of ...

    African Journals Online (AJOL)

    Population dynamics and biology of an invasive population of mosquitofish Gambusia affinis in a temperate estuarine lake system. Hans Sloterdijk, Nicola C. James, M Kyle S. Smith, Werner Ekau, Olaf L.F. Weyl ...

  8. Standard Populations (Millions) for Age-Adjustment - SEER Population Datasets

    Science.gov (United States)

    Download files containing standard population data for use in statististical software. The files contain the same data distributed with SEER*Stat software. You can also view the standard populations, either 19 age groups or single ages.

  9. Population's political clout.

    Science.gov (United States)

    Schima, M E; Viel, B; Chen, P C; Gille, H; Epstein, S G

    1980-03-01

    China's birth planning program has its own separate administrative hierarchy. The political commitment to population planning which originates with the top leadership extends to peer pressure exerted on couples at the brigade and neighborhood level. While family planning services are primarily delivered in health structures, responsibility for the population program falls to the Leading Group on Birth Planning. Not only health officials but also officials responsible for economic planning, political propaganda, scientific research, trade unions, women's affairs, and all those whose participation is considered necessary to the program's success attend meeting. The Leading Group on Birth Planning is chaired by a Vice-Premier. At each administrative level, provincial to work brigade, the same pattern is repeated: centralized responsibility combined with broad representation and high-level potitical leadership. With a tight, working structure, China has been able to enact its birth control program with remarkable speed and effectiveness. Each production brigade has its own planned birth leading group headed by the captain of the brigade or the captain of the women's team. The leading group supervises the barefoot doctors, midwives, and team level health aides who deliver contraceptives to households or accompany people to the community health center to obtain surgical services.

  10. The aging population in Brazil

    Directory of Open Access Journals (Sweden)

    Fabio Nasri

    2008-03-01

    Full Text Available Brazil is currently in an advanced stage of both the mortality andfertility transitions, which allows one to confi dently forecast the agedistribution and population size over the next four decades. Whereasthe elderly population with more than 65 years will increase at highrates (2 to 4% per year the young population will decline. Accordingto United Nations projections, the elderly population will increasefrom 3.1% of the population in 1970 to 19% in 2050. The changingage distribution of the Brazilian population brings opportunities andchallenges that could lead to serious social and economic issues ifnot dealt with properly in coming decades.

  11. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  12. Population Trends and the Status of Population Policy in Africa.

    Science.gov (United States)

    Rogge, John R.

    1982-01-01

    The major trend towards worldwide easing of the birthrate does not include the current population patterns in Africa. The population policies of African nations range along a continuum from totally pronatal to strongly antinatal. However, even antinatal policies have had little effect on the overall spiralling upward population trend. (JA)

  13. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  14. CDC WONDER: Population (from Census)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population online databases contain data from the US Census Bureau. The Census Estimates online database contains contains county-level population counts for...

  15. NASA Orbital Debris Baseline Populations

    Science.gov (United States)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  16. Millennium Ecosystem Assessment: MA Population

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Population data sets provide baseline population information as one of the drivers of ecosystem change. The data helped in...

  17. Stochastic population theories

    CERN Document Server

    Ludwig, Donald

    1974-01-01

    These notes serve as an introduction to stochastic theories which are useful in population biology; they are based on a course given at the Courant Institute, New York, in the Spring of 1974. In order to make the material. accessible to a wide audience, it is assumed that the reader has only a slight acquaintance with probability theory and differential equations. The more sophisticated topics, such as the qualitative behavior of nonlinear models, are approached through a succession of simpler problems. Emphasis is placed upon intuitive interpretations, rather than upon formal proofs. In most cases, the reader is referred elsewhere for a rigorous development. On the other hand, an attempt has been made to treat simple, useful models in some detail. Thus these notes complement the existing mathematical literature, and there appears to be little duplication of existing works. The authors are indebted to Miss Jeanette Figueroa for her beautiful and speedy typing of this work. The research was supported by the Na...

  18. [[Population and industrial development

    Science.gov (United States)

    Charoenloet, V

    "Concurrent with the decline in population growth rate in the 1980s, Thailand experienced an unprecedented rate of economic growth....Such phenomenal economic growth has generally been attributed to the internationalization of the Thai economy through the rapid expansion of exports, foreign investment and tourism. However, industries in the manufacturing sector...tend to be resource-based and labour-intensive. Moreover, foreign investment in export-oriented industries tends to use Thailand as a base for assembling rather than producing goods and has been attracted primarily by cheap labour cost. All these may contribute to the employment of [a] nonskilled, lowly-paid labour force, but not the development of scientific/technology based industries, the foundation for permanent and lasting economic development." (SUMMARY IN ENG) excerpt

  19. [Excessive population and health].

    Science.gov (United States)

    Rivera, A A

    1995-07-01

    Population density in El Salvador is among the highest in the world. In metropolitan San Salvador and the other main cities, crowding, squatter settlements, unemployment and underemployment, scarcity of basic services, squalor, and other social pathologies appear to be increasing. Overpopulation poses an enormous challenge for development. Reflection on the benefits of family planning has been delayed in El Salvador, and in the interim there have been increases in social inequality, misery, and hunger. Family planning programs have been referred to as "neo-Malthusian" and contrary to the right to life, but in fact they promote birth spacing and free selection of methods by couples, contributing to improvement in the quality of family life. Family planning allows couples to limit their offspring to those they can adequately care for emotionally and materially. People must be shown that family planning alleviates many of humanity's problems.

  20. Refining population health comparisons

    DEFF Research Database (Denmark)

    Hussain, M. Azhar; Jørgensen, Mette Møller; Østerdal, Lars Peter Raahave

    2016-01-01

    How to determine if a population group has better overall (multidimensional) health status than another is a central question in the health and social sciences. We apply a multidimensional first order dominance concept that does not rely on assumptions about the relative importance of each...... dimension. In particular, we show how one can explore the “depth” of dominance relations by gradually refining the health dimensions to see which dominance relations persist. We analyze a Danish health survey with many health indicators. These are initially collapsed into a single composite health dimension...... and then refined to four, seven, and ten health dimensions, each representing an (increasingly refined) area of health. Overall we find that younger age groups dominate older age groups in up to four dimensions, but no dominance relations are present with a more refined view of health. Comparing education groups...

  1. Population, environment, and development.

    Science.gov (United States)

    Myers, N

    1993-01-01

    The strategies for reducing population growth include social development and improvement in the educational attainment of women. The decline in Kenya's growth rate was attributed to high female literacy and reduced infant mortality. Another strategy for enhancing fertility decline is to reduce child mortality, particularly from preventable causes such as diarrhea. The entire cost of such a strategy to reduce preventable disease would be about $1.33 per 300 million taxpayers in developed countries. Family planning services must be expanded. Prevention of maternal mortality and AIDS would bring major benefits. Strategies for environmental protection emphasized the already existing plan of action set out in the UNCED document Agenda 21 in Rio de Janeiro. The plan has suffered from inaction. The estimated cost of $625 million was considered to be several times smaller than the costs of inaction. The elimination of subsidies in tropical forests would have an immediate impact. Natural resource accounting at the national level would include the value of natural resources. Pricing would change radically for gasoline if the costs of urban smog, acid rain, low-level ozone pollution, and global warming were taken into account. Strategies for sustainable development pertained to the preceding strategies and others indicated in the Agenda 21 Action Plan. If funding were better targeted to the poorest 20% of global population with high fertility rates, the accomplishments would be heralded. 1.2 million are living in absolute poverty, and aid for nutrition, primary health care, water and sanitation, basic education, and family planning amounts to only 10% of expenditures. An increase to 20% would mean a contribution from Americans of $7.50 per person or 33% of $25 thousand million from all developed countries. Developing countries need to lower their military expenditures, privatize public enterprises, change inappropriate development policies, eliminate corruption, and improve

  2. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  3. Population genetics without intraspecific data

    DEFF Research Database (Denmark)

    Thorne, Jeffrey L; Choi, Sang Chul; Yu, Jiaye

    2007-01-01

    populations, and parameters of interspecific models should have population genetic interpretations. We show, with two examples, how population genetic interpretations can be assigned to evolutionary models. The first example considers the impact of RNA secondary structure on sequence change, and the second...... genetic interpretation. Udgivelsesdato: 2007-Aug...

  4. [Population ethics and growth].

    Science.gov (United States)

    Boim, D

    1988-01-01

    In order to formulate and implement a national demographic policy, various areas of science are called upon; however, since human lives are involved, ethical aspects play an important role not only in broad ideological terms, e.g, concerning overpopulation, but whenever practical decisions affecting technology and human resources are made. The article describes how the Catholic Church proposes certain "utopian" views or interpretations as part of an ethical "dynamism" and plurality needed when addressing the problem of overpopulation. 3 main starting point are defined for the determination of a population ethic: 1) ethics defined in terms of "nature," 2) in terms of the "human person," and 3) in terms of social "dialectic" involvement. The first point stresses the natural order of things as prescribed by God and impugns any birth control method; however, so-called natural birth control methods are allowed. The second point suggests that the human person is ethically center stage, a modernized position taken by the Church in tune with social realities and man's inherent intelligence. The primacy of live and responsibility is stressed as opposed to mere biological processes. Following this view, use of contraceptive, and even sterilization is allowed; however, abortion is excluded, since it means the elimination of a human life. The problem of overpopulation should be solved within the individual or micro-social context. The third point holds that it would be extremely myopic to reduce the position of the Church to advocating exclusively natural birth control methods while excluding social involvement. A "cosmic" view of faith would end putting material well-being before individual personal lives, would alert against egoism disguised as quality of life enhancement, and ultimately result in socially responsible fertility. In conclusion, the Church acknowledges that its contribution to the question of population ethics occurs in a pluralistic society that does not

  5. Anaerobic fungal populations

    International Nuclear Information System (INIS)

    Brookman, J.L.; Nicholson, M.J.

    2005-01-01

    The development of molecular techniques has greatly broadened our view of microbial diversity and enabled a more complete detection and description of microbial communities. The application of these techniques provides a simple means of following community changes, for example, Ishii et al. described transient and more stable inhabitants in another dynamic microbial system, compost. Our present knowledge of anaerobic gut fungal population diversity within the gastrointestinal tract is based upon isolation, cultivation and observations in vivo. It is likely that there are many species yet to be described, some of which may be non-culturable. We have observed a distinct difference in the ease of cultivation between the different genera, for example, Caecomyes isolates are especially difficult to isolate and maintain in vitro, a feature that is likely to result in the under representation of this genera in culture-based enumerations. The anaerobic gut fungi are the only known obligately anaerobic fungi. For the majority of their life cycles, they are found tightly associated with solid digesta in the rumen and/or hindgut. They produce potent fibrolytic enzymes and grow invasively on and into the plant material they are digesting making them important contributors to fibre digestion. This close association with intestinal digesta has made it difficult to accurately determine the amount of fungal biomass present in the rumen, with Orpin suggesting 8% contribution to the total microbial biomass, whereas Rezaeian et al. more recently gave a value of approximately 20%. It is clear that the rumen microbial complement is affected by dietary changes, and that the fungi are more important in digestion in the rumens of animals fed with high-fibre diets. It seems likely that the gut fungi play an important role within the rumen as primary colonizers of plant fibre, and so we are particularly interested in being able to measure the appearance and diversity of fungi on the plant

  6. Population Health and Occupational Therapy.

    Science.gov (United States)

    Braveman, Brent

    2016-01-01

    Occupational therapy practitioners play an important role in improving the health of populations through the development of occupational therapy interventions at the population level and through advocacy to address occupational participation and the multiple determinants of health. This article defines and explores population health as a concept and describes the appropriateness of occupational therapy practice in population health. Support of population health practice as evidenced in the official documents of the American Occupational Therapy Association and the relevance of population health for occupational therapy as a profession are reviewed. Recommendations and directions for the future are included related to celebration of the achievements of occupational therapy practitioners in the area of population health, changes to the Occupational Therapy Practice Framework and educational accreditation standards, and the importance of supporting, recognizing, rewarding, and valuing occupational therapy practitioners who assume roles in which direct care is not their primary function. Copyright © 2016 by the American Occupational Therapy Association, Inc.

  7. Lithuanian Population Aging Factors Analysis

    Directory of Open Access Journals (Sweden)

    Agnė Garlauskaitė

    2015-05-01

    Full Text Available The aim of this article is to identify the factors that determine aging of Lithuania’s population and to assess the influence of these factors. The article shows Lithuanian population aging factors analysis, which consists of two main parts: the first describes the aging of the population and its characteristics in theoretical terms. Second part is dedicated to the assessment of trends that influence the aging population and demographic factors and also to analyse the determinants of the aging of the population of Lithuania. After analysis it is concluded in the article that the decline in the birth rate and increase in the number of emigrants compared to immigrants have the greatest impact on aging of the population, so in order to show the aging of the population, a lot of attention should be paid to management of these demographic processes.

  8. Climate and waterfowl populations

    International Nuclear Information System (INIS)

    Diamond, A.W.; Brace, R.K.

    1991-01-01

    Climate affects waterfowl populations through a variety of pathways, categorized as direct impacts (physiological effects on the bird itself), and indirect, acting through the bird's habitats and changes in land use practices. Graphs are presented of wetland use by Prairie ducks, duck use by pothole size and class, duck use by wetland type, wetland use by grebes, numbers of nongame birds, wetland use by shorebirds and wetland use by blackbirds. Wetlands are classified according to the following scheme: ephemeral and temporary, which are shallow and are first to thaw in the spring; seasonal, which become available later in the year and last longer; semipermanent wetlands, which hold water well into late summer; permanent wetlands, which are relatively less productive than other types, and which are mainly used as staging habitat for fall migration; and alkali wetlands, which are relatively little used. The types of wetland available to waterfowl and other migratory birds are as important as numbers and total area. In general, smaller wetlands are more important than larger, more permanent water bodies. Small, impermanent wetlands are more vulnerable to climatic warming and drying, and species such as waterfowl and migratory birds in general are at great risk from further drying of the hydrological regime of the Prairies and Great Plains. 12 refs., 9 figs

  9. population in Slovakia

    Directory of Open Access Journals (Sweden)

    Dravecký Miroslav

    2015-06-01

    Full Text Available V rokoch 2011 – 2014 sa realizoval monitoring hniezdnej populácie orla krikľavého (Aquila pomarina v ôsmich chránených vtáčích územiach na Slovensku. U 149 hniezdnych párov z celkových 272 úspešných hniezdení počas 4 hniezdnych sezón vyletelo 277 mláďat. Priemerná reprodukčná úspešnosť predstavovala 0,51 juv./prítomný pár, 0,69 juv./hniezdiaci pár a 1,37 juv./100 km2. V uvedenom období bolo okolo hniezd orlov krikľavých ustanovených celkom 151 ochranných zón, ktoré zabezpečili ochranu 119 hniezdnych teritórií, čo predstavuje cca 17 % hniezdnej populácie orla krikľavého na Slovensku. Testovaním účinnosti ochranných zón sa zistilo, že v hniezdach s vyhlásenou ochrannou zónou je vyššia pravdepodobnosť úspešného odchovania mláďat v porovnaní s hniezdami bez takejto zóny. Pravdepodobnosť, že hniezdenie bude úspešné v hniezdach hniezdiacich párov bez ochrannej zóny bola 48.1% (95% confidence intervals (CIs: 37.4–59.0%, v hniezdach s ochrannou zónou 64.8% (95% CIs: 59.8–69.6%. Medzi 5 najčastejšie využívaných hniezdnych stromov na hniezdenie A. pomarina na Slovensku patrí Picea abies 61× (28,4%, Pinus sylvestris 45× (20,9%, Quercus sp. 36× (16,7%, Fagus sylvatica 25× (11,6% a Abies alba 18× (8,4%. Medzi zriedkavejšie druhy hniezdnych stromov patrí Larix decidua 12× (5,6% a Alnus glutinosa 3× (1,4%, ďalších 11 druhov hniezdnych stromov nedosiahli 1 %. Najvyšší počet hniezdnych stromov (n = 215, tj. 34 hniezd (15,8% sa nachádzal v intervale nadmorskej výšky 401 – 450 m a 29 hniezd (13,5% v intervale 351 – 400 m n. m. Ostatné výškové pásma boli pod hranicou 10%. 54% zistených hniezd (116 hniezd sa nachádza vo výškovom pásme 301 – 600 m n. m., 71 hniezd (33% v pásme 600 – 900 m n. m. Najnižšie situované hniezdo bolo v nadmorskej výške 150 m a najvyššie 950 m, priemer bol 595,01 m. Najvyšší počet hniezd (n = 209 bol na strome

  10. Browsing Isolated Population Data

    Directory of Open Access Journals (Sweden)

    Manias Teresa

    2005-12-01

    Full Text Available Abstract Background In our studies of genetically isolated populations in a remote mountain area in the center of Sardinia (Italy, we found that 80–85% of the inhabitants of each village belong to a single huge pedigree with families strictly connected to each other through hundreds of loops. Moreover, intermarriages between villages join pedigrees of different villages through links that make family trees even more complicated. Unfortunately, none of the commonly used pedigree drawing tools are able to draw the complete pedigree, whereas it is commonly accepted that the visual representation of families is very important as it helps researchers in identifying clusters of inherited traits and genotypes. We had a representation issue that compels researchers to work with subsets extracted from the overall genealogy, causing a serious loss of information on familiar relationships. To visually explore such complex pedigrees, we developed PedNavigator, a browser for genealogical databases properly suited for genetic studies. Results The PedNavigator is useful for genealogical research due to its capacity to represent family relations between persons and to make a visual verification of the links during family history reconstruction. As for genetic studies, it is helpful to follow propagation of a specific set of genetic markers (haplotype, or to select people for linkage analysis, showing relations between various branch of a family tree of affected subjects. Availability PedNavigator is an application integrated into a Framework designed to handle data for human genetic studies based on the Oracle platform. To allow the use of PedNavigator also to people not owning the same required informatics infrastructure or systems, we developed PedNavigator Lite with mainly the same features of the integrated one, based on MySQL database server. This version is free for academic users, and it is available for download from our site http://www.shardna.com.

  11. Population adiposity and climate change.

    Science.gov (United States)

    Edwards, Phil; Roberts, Ian

    2009-08-01

    The increasing global prevalence of overweight and obesity has serious implications for the environment, as well as for health. We estimate the impact on greenhouse gas emissions of increases in the population distribution of body mass index (BMI). We estimated the food energy required to maintain basal metabolic rate in two hypothetical adult populations using the Schofield equations for males and females. Additional greenhouse gas emissions due to higher fuel energy use for transporting a heavier population were estimated. Compared with a normal population distribution of BMI, a population with 40% obese requires 19% more food energy for its total energy expenditure. Greenhouse gas emissions from food production and car travel due to increases in adiposity in a population of 1 billion are estimated to be between 0.4 Giga tonnes (GT) and 1.0 GT of carbon dioxide equivalents per year. The maintenance of a healthy BMI has important environmental benefits in terms of lower greenhouse gas emissions.

  12. Singapore’s Declining Population

    Science.gov (United States)

    2010-01-01

    ethnic groups work . In addition, they get married later in life and had fewer children. What does a declining population mean for Singapore...other countries. BACKGROUND Since gaining independence, Singapore’s population has grown along with its economy . As Singapore’s gross domestic...in the country mean fewer consumers. Fewer people in the country also means there are less people to support the elderly. As the population ages

  13. Evolutionary dynamics of diploid populations

    Science.gov (United States)

    Desimone, Ralph; Newman, Timothy

    2003-10-01

    There has been much recent interest in constructing computer models of evolutionary dynamics. Typically these models focus on asexual population dynamics, which are appropriate for haploid organsims such as bacteria. Using a recently developed ``genome template'' model, we extend the algorithm to a sexual population of diploid organisms. We will present some early results showing the temporal evolution of mean fitness and genetic variation, and compare this to typical results from haploid populations.

  14. Determinants of human population growth.

    Science.gov (United States)

    Lutz, Wolfgang; Qiang, Ren

    2002-09-29

    The 20th century has seen unprecedented growth of the human population on this planet. While at the beginning of the century the Earth had an estimated 1.6 billion inhabitants, this number grew to 6.1 billion by the end of the century, and further significant growth is a near certainty. This paper tries to summarize what factors lie behind this extraordinary expansion of the human population and what population growth we can expect for the future. It discusses the concept of demographic transition and the preconditions for a lasting secular fertility decline. Recent fertility declines in all parts of the world now make it likely that human population growth will come to an end over the course of this century, but in parts of the developing world significant population growth is still to be expected over the coming decades. The slowing of population growth through declining birth rates, together with still increasing life expectancy, will result in a strong ageing of population age structure. Finally, this paper presents a global level systematic analysis of the relationship between population density on the one hand, and growth and fertility rates on the other. This analysis indicates that in addition to the well-studied social and economic determinants, population density also presents a significant factor for the levels and trends of human birth rates.

  15. Population genetic analysis of cat populations from Mexico ...

    Indian Academy of Sciences (India)

    Unknown

    In this paper we identify new genetic profiles of eight Latin American cat populations. In addition, we combine data from the present study and previously published data on 70 other American and European populations to discuss (1) the points of introduction of mutant alleles for cat coat phenotypes from Europe into Latin ...

  16. Population dynamics and population control of Galium aparine L.

    NARCIS (Netherlands)

    Weide, van der R.Y.

    1993-01-01

    The population biology of Galium aparine L. needs to be better understood, in order to be able to rationalize decisions about the short- and long-term control of this weed species for different cropping practices.

    A population dynamics model was developed to

  17. Population genetic analysis of cat populations from Mexico ...

    Indian Academy of Sciences (India)

    Unknown

    Bolivia, and the Dominican Republic: identification of different gene pools in Latin America. J. Genet. 84, 147–171]. Introduction. The genetic ... populations has led to the identification of genetic rela- tionships among populations and ...... Evolution 44, 689–697. Rao C. R. 1951. Advanced statistical methods in biometric re-.

  18. Part II. Population

    International Nuclear Information System (INIS)

    2004-01-01

    This monograph deals with assessment of radiological health effects of the Chernobyl accident for emergency workers (part 1) and the population of the contaminated areas in Russia (part 2). The Chernobyl emergency workers and people living in the contaminated areas of Russia received much lower doses than the population of Hiroshima and Nagasaki and it was unclear whether risks of radiation-induced cancers derived with the Japanese data could be extrapolated to the low dose range However, it was predicted as early as in 1990 that the thyroid cancer incidence might be increasing due to incorporated 131 irradiation. What conclusions can be drawn from regarding cancer incidence among emergency workers and residents of the contaminated areas in Russia and the role of the radiation factor on the basis of the registry data? Leukemia incidence. Leukemia incidence is known to be one of principal indications of radiation effects. The radiation risk for leukemias is 3-4 times higher that for solid cancers and its latent period is estimated to be 2-3 years after exposure. Results of the radiation epidemiological studies discussed in this book show that in the worst contaminated Bryansk region the leukemia incidence rate is not higher than in the country in general. Even though some evidence exists for the dose response relationship, the radiation risks appear to be not statistically significant. Since risks of leukemia are known to be higher for those who were children at exposure, long-term epidemiological studies need to be continued. The study of leukemias among emergency workers strongly suggest the existence of dose response relationship. In those who received external doses more than 0.15 Gy the leukemia incidence rate is two time higher and these emergency workers should be referred to as a group of increased radiation risk. Solid cancers. The obtained results provide no evidence to a radiation-induced increase in solid cancers among residents of the contaminated areas

  19. Stochastic delocalization of finite populations

    International Nuclear Information System (INIS)

    Geyrhofer, Lukas; Hallatschek, Oskar

    2013-01-01

    The localization of populations of replicating bacteria, viruses or autocatalytic chemicals arises in various contexts, such as ecology, evolution, medicine or chemistry. Several deterministic mathematical models have been used to characterize the conditions under which localized states can form, and how they break down due to convective driving forces. It has been repeatedly found that populations remain localized unless the bias exceeds a critical threshold value, and that close to the transition the population is characterized by a diverging length scale. These results, however, have been obtained upon ignoring number fluctuations (‘genetic drift’), which are inevitable given the discreteness of the replicating entities. Here, we study the localization/delocalization of a finite population in the presence of genetic drift. The population is modeled by a linear chain of subpopulations, or demes, which exchange migrants at a constant rate. Individuals in one particular deme, called ‘oasis’, receive a growth rate benefit, and the total population is regulated to have constant size N. In this ecological setting, we find that any finite population delocalizes on sufficiently long time scales. Depending on parameters, however, populations may remain localized for a very long time. The typical waiting time to delocalization increases exponentially with both population size and distance to the critical wind speed of the deterministic approximation. We augment these simulation results by a mathematical analysis that treats the reproduction and migration of individuals as branching random walks subject to global constraints. For a particular constraint, different from a fixed population size constraint, this model yields a solvable first moment equation. We find that this solvable model approximates very well the fixed population size model for large populations, but starts to deviate as population sizes are small. Nevertheless, the qualitative behavior of the

  20. [Population science serves human happiness].

    Science.gov (United States)

    Qian, X

    1983-03-29

    4 areas are covered in this speech delivered on January 10, 1983. 1) Looking back on China's post-Liberation population problems: as early as the 1950s, the Party and scholars such as Ma Yinchu recognized the need to control population growth. For instance, a 1952 directive instructed the Public Health Bureau to encourage the use of condoms and diaphrams. When Ma Yinchu's studies showing alarming population increases were made known to Mao Zedong and published in the People's Daily in 1957, the "new population theory" was formed, which advocated population control. But before this idea gained currency, Ma suffered criticism in 1958 and population studies was virtually halted. Between 1958-61, as China entered difficult times, the birthrate declined. By 1962 the rate increased, leading the Central Committee of the Chinese Communist Party to issue a directive to control population. Again in 1971 the Central Government set population goals and incorporated population policies into national economic planning. When the wrongs of the Cultural Revolution were redressed, Ma Yinchu regained favor and demography entered a new era. 2) The responsibility of demographic studies: one of the most important tasks of demography is to solve the problem of confining the birthrate to 16-17/1000 annually, so that by 2000 the total population would be 1,200,000,000. This can only be done by advocating 1 child per couple, closely con trolling a 2nd birth and discouraging all 3rd births. 3) The contents of demographic studies: both immediate and future problems must be addressed. Areas of study can include sex ratio, marriage, family, population and land distribution, fertility, or an aging society. 4) Science research must embody a scientific attitude: it is best to follow the example set by Ma Yinchu, whose work was based on actual investigations in the field. Any development and production of scientific theory must stem from practical experience.

  1. Estimated population near uranium tailings

    International Nuclear Information System (INIS)

    Bloomster, C.H.; Brown, D.R.; Bruno, G.A.; Craig, S.N.; Dirks, J.A.; Griffin, E.A.; Reis, J.W.; Young, J.K.

    1984-01-01

    Population studies, which took place during the months of April, May, and June 1983, were performed for 27 active and 25 inactive mill sites. For each mill site, a table showing population by radius (1/2, 1, 2, 3, 4, and 5 km) in 16 compass directions was generated. 22 references, 6 tables

  2. Do people fear population decline?

    NARCIS (Netherlands)

    van Dalen, H.P.; Henkens, C.J.I.M.

    2011-01-01

    This week the world population is projected to reach seven billion. Yet in some countries the prospect of a decline in population is worrying policymakers far more. This columns asks what the people think, focusing on a survey from the Netherlands. It turns out that most people are in favour of

  3. U.S. Population Growth.

    Science.gov (United States)

    Dillner, Harry

    This autoinstructional lesson deals with the study of man and his environment. No previous experience or learning in this field is required. Emphasis is placed on analysis of population growth and the impact population growth and trends have on natural resource depletion. The behavioral objectives (five) are listed. The study guide for the…

  4. Food for the ageing population

    NARCIS (Netherlands)

    Raats, M.M.; Groot, de C.P.G.M.; Staveren, van W.A.

    2008-01-01

    The world’s ageing population is increasing and food professionals will have to address the needs of older generations more closely in the future. This unique volume reviews the characteristics of the ageing population as food consumers, the role of nutrition in healthy ageing and the design of food

  5. Mega-Planning in Population

    Science.gov (United States)

    Clark, Sarah C.; Murray, Margo

    2005-01-01

    Clark and Murray examine the six Critical Performance Factors for Mega planning in an example drawn from the five-year history of the population program of a major west coast philanthropy. In this article, the authors describe the salience and scope of the population issue as it is relates to other global trends; the steps the foundation took to…

  6. Population Growth: Crisis and Challenge.

    Science.gov (United States)

    Beaton, John R., Ed.; Doberenz, Alexander R., Ed.

    The proceedings of this first annual symposium on population growth considers the consequences of this growth, along with possible means of regulation. Topics of speeches include: Population Outlook in Asia (Irene Taeuber); Malnutrition is a Problem of Ecology (Paul Gyorgy); The Leisure Explosion (E. H. Storey); Effects of Pollution on Population…

  7. Paths for Future Population Aging.

    Science.gov (United States)

    Grigsby, Jill S.

    Population aging refers to an entire age structure becoming older. The age structure of a population is the result of three basic processes: fertility, mortality, and migration. Age structures reflect both past effects and current patterns of these processes. At the town, city, or regional level, migration becomes an important factor in raising…

  8. Population. Environmental Ecological Education Project.

    Science.gov (United States)

    Parkway School District, Chesterfield, MO.

    This unit on population, designed for senior high school students, is divided into six packets with the following major topics: general introduction to the effects of a growing population, urbanization, family structures, family planning, consumption, environmental decay, and controlling the environment. Each packet contains a list of the topical…

  9. Assessment of ASEAN population programme.

    Science.gov (United States)

    1982-01-01

    The objectives of the 5th meeting of the ASEAN Heads of Population Program, held at Chiang Mai during November 1981, were the following: to discuss and consider the midterm reviews of some of the Phase 1 projects; to discuss and consider the ASEAN population experts' views on the progress made in the rest of the phase 1 projects; to discuss and consider the progress made in the implementation of the phase 2 projects; to discuss and consider the ASEAN population experts' recommendations on the ASEAN population program in the 1980s based on the report of the programming exercise submitted by the consultant in the expert group meeting; and to discuss administrative and other problems faced by the program implementors in the operationalization of the ongoing ASEAN population projects and provide appropriate directions to solve such problems. As a result of the programming exercise, the meeting established the directions for the future ASEAN population program and strongly recommended the continuation, intensification, and expansion of the ASEAN population program. A total of 12 projects comprise the ASEAN population program: 5 projects under phase 1 and 7 under phase 2. Under phase 1, 1 project has been completed, and the 1st parts of 2 other projects are in the process of implementation. Phase 2 projects, which started in September/October 1980, are all in the process of implementation. The following phase 1 projects are summarized: integration of population and rural development policies and programs; modular training for trainers of population and development agencies in ASEAN countries; multi-media support for population programs in the context of rural development in ASEAN countries; and migration in relation to rural development. The following phase 2 projects are also summarized: institutional development and exchange of personnel; women in development in ASEAN countries; and migration in relation to rural development. The following phase 2 projects are also

  10. Population information, education and communication.

    Science.gov (United States)

    1995-09-01

    Over the years UNFPA has used the information, education, and communication strategy to create awareness about population issues in more than 100 countries. The annual UNFPA publication The State of World Population has received worldwide media attention. Population issues are also aired through the annual World Population Day, which includes an international poster competition. Radio is used for spreading the message of population control but it could be employed more effectively given the 1.9 billion radio sets in the world. In Peru community-operated radio stations offer information on immunizations, reproductive health, and family planning. Some 20 countries have launched their own television programs in the form of mini-dramas to promote reproductive health and family planning. Mexico's family planning soap opera is highly popular in other Latin American countries. Multimedia campaigns are the most effective way of increasing public awareness about population and health-related issues. In Egypt the state-controlled television network is running a highly successful series of family planning mini-dramas. The country's contraceptive prevalence rate was nearly 50% in 1995 and rising. Similar successes have been reported in Mexico and Turkey. The growth of regional and international population information networks has been decisive in disseminating information. These include the UN Population Information Network (POPIN); the POPIN ASEAN for members of the Association of South-East Asian Nations (ASEAN); POPIN Africa; DOCPAL set up for Latin American countries; and PROLAP with the participation of 50 nongovernmental organizations. In the 1960s and 1970s population education also rapidly expanded in schools, and by the mid-1980s about 80 countries had population education in their schools. As of 1994 about 100 countries had such projects in schools. In addition, more attention is paid in schools to family planning, human sexuality, and gender issues. The major

  11. [Population problems and theories in old China].

    Science.gov (United States)

    Li, S

    1980-03-01

    Population theories in China before the revolution are reviewed. The author considers whether there was a population problem, whether a surplus population did exist, and to what extent population pressures existed.

  12. Human Population: Fundamentals of Growth and Change.

    Science.gov (United States)

    Stauffer, Cheryl Lynn, Ed.

    This booklet focuses on eight elements of population dynamics: "Population Growth and Distribution"; "Natural Increase and Future Growth"; "Effect of Migration on Population Growth"; "Three Patterns of Population Change"; "Patterns of World Urbanization"; "The Status of Women";…

  13. Bangladesh. Population education programme reviewed.

    Science.gov (United States)

    1995-01-01

    The UNFPA (UN Population Fund)-funded population education program was reviewed last November 1994 in order to identify the emerging needs and requirements as well as chart the future directions of the program. The review was undertaken with the assistance of the CST SAWA Adviser on Population Education, Dr. D.M. de Rebello. Comprehensive literature review, and intensive discussions with government functionaries, educationists, teachers, students, UNFPA country director and staff and concerned officials of the World Bank and other UN agencies involved in the program served as the modalities for the review. The review looked into the current status of the school education sector and assessed the present progress of the population education program vis-a-vis its objectives and achievements. It also analyzed the issues and constraints in relation to institutionalization of the program, capacity building and integration of population education in curriculum and textbooks. Among the many recommendations, the review proposed further building up of national capacities at various levels; development of teaching/learning materials and textbooks for the new sectors; and intensification of good quality teacher education. Institutionalization of population education in the formal school system up to grade 12 and in technical and vocational education as well as the madrasah system and the introduction of population education in the Mass Non-formal Education Program were also proposed. full text

  14. Modern population trends in Bangladesh.

    Science.gov (United States)

    Abul-basher, M M

    1985-01-01

    Population growth trends in Bangladesh in the 1871-1981 period were analyzed, with emphasis on fertility and mortality differentials, to provide a basis for population planning. Following proclamation of British Imperial Rule in 1857, mortality rates in Bangladesh began to decline as a result of preventive measures against natural disasters such as draught and famine, but the fertility rate remained unaltered. The demographic pattern was unstable over time, reflecting the impact of the influenza epidemic of 1918-19, war, migration, and economic development. Population growth accelerated greatly during the 1961-74 period, when industrialization emerged and job opportunities were created in the urban centers. Economic hardship, food shortages, and the introduction of family planning curbed urban growth drastically and total growth to some extent in 1974-81. On the average, growth has been higher in the Dhaka and Chittagong Divisions of Bangladesh than in the Khulna and Rajshahi Divisions. Differences in population growth among the regions are attributable largely to internal and external migration. The regression polynomial model best fits past population trends in Bangladesh and can reproduce the observed population by 99.60%. This polynomial is most suitable for graduation and prediction of population trends.

  15. Can human populations be stabilized?

    Science.gov (United States)

    Warren, Stephen G.

    2015-02-01

    Historical examples of demographic change, in China, Italy, Nigeria, Utah, Easter Island, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are wrong because they assume, in spite of the absence of necessary feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food.

  16. NIDI scenario. Strong population decline in China

    OpenAIRE

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario projects less population growth in Nigeria and sharp population decline in China.

  17. Population and resources in Mauritius.

    Science.gov (United States)

    Royle, S A

    1995-05-01

    "The island of Mauritius was facing a crisis by the 1950s as the relationship between its population and resources became unbalanced....A two-pronged strategy was set in place to change the relationship between population and resources. Firstly, an aggressive family-planning policy was established, reducing population growth. Secondly, the economy was diversified with tourism, financial services and, especially, manufacturing in the Mauritius Export Processing Zone, creating extra finance and resources. The changes have not been cost-free but Mauritius ends the century, not as a classic case of overpopulation, but more [as] a model micro-state that has overcome many population and resource problems, largely through its own efforts." excerpt

  18. Population Issues. Resources in Technology.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    Presents information about the problems caused by increasing population. Discusses the environmental impact and the ways that technology can be used to solve problems of overpopulation. Includes possible student outcomes and a student quiz. (JOW)

  19. Wolf population genetics in Europe

    DEFF Research Database (Denmark)

    Hindrikson, Maris; Remm, Jaanus; Pilot, Malgorzata

    2017-01-01

    , resulting in a significant decrease in their numbers, genetic diversity and gene flow between populations. For more effective protection and management of wolf populations in Europe, robust scientific evidence is crucial. This review serves as an analytical summary of the main findings from wolf population...... genetic studies in Europe, covering major studies from the ‘pre-genomic era’ and the first insights of the ‘genomics era’. We analyse, summarize and discuss findings derived from analyses of three compartments of the mammalian genome with different inheritance modes: maternal (mitochondrial DNA), paternal...... (Y chromosome) and biparental [autosomal microsatellites and single nucleotide polymorphisms (SNPs)]. To describe large-scale trends and patterns of genetic variation in European wolf populations, we conducted a meta-analysis based on the results of previous microsatellite studies and also included...

  20. Evacuating populations with special needs

    Science.gov (United States)

    2009-04-01

    Evacuation operations are conducted under the authority of, and based on decisions by, local and state authorities. The purpose of this primer, Evacuating Populations with Special Needs, is to provide local and state emergency managers, government of...

  1. The Veteran Population Projection 2014

    Data.gov (United States)

    Department of Veterans Affairs — VetPop2014 is an actuarial projection model developed by the Office of the Actuary (OACT) for Veteran population projection from Fiscal Year FY2014 to FY2043. Using...

  2. Modeled population exposures to ozone

    Data.gov (United States)

    U.S. Environmental Protection Agency — Population exposures to ozone from APEX modeling for combinations of potential future air quality and demographic change scenarios. This dataset is not publicly...

  3. Correctional Facility Average Daily Population

    Data.gov (United States)

    Montgomery County of Maryland — This dataset contains Accumulated monthly with details from Pre-Trial Average daily caseload * Detention Services, Average daily population for MCCF, MCDC, PRRS and...

  4. Information processing by neuronal populations

    National Research Council Canada - National Science Library

    Hölscher, Christian; Munk, Matthias

    2009-01-01

    ... simultaneously recorded spike trains 120 Mark Laubach, Nandakumar S. Narayanan, and Eyal Y. Kimchi Part III Neuronal population information coding and plasticity in specific brain areas 149 7 F...

  5. India's population: second and growing.

    Science.gov (United States)

    Visaria, P; Visaria, L

    1981-10-01

    Attention in this discussion of the population of India is directed to the following: international comparisons, population pressures, trends in population growth (interstate variations), sex ratio and literacy, urban-rural distribution, migration (interstate migration, international migration), fertility and mortality levels, fertility trends (birth rate decline, interstate fertility differentials, rural-urban fertility decline, fertility differentials by education and religion, marriage and fertility), mortality trends (mortality differentials, health care services), population pressures on socioeconomic development (per capita income and poverty, unemployment and employment, increasing foodgrain production, school enrollment shortfalls), the family planning program, implementing population policy statements, what actions would be effective, and goals and prospects for the future. India's population, a total of 684 million persons as of March 1, 1981, is 2nd only to the population of China. The 1981 population was up by 136 million persons, or 24.75%, over the 548 million enumerated in the 1971 census. For 1978, India's birth and death rates were estimated at 33.3 and 14.2/1000 population, down from about 41.1 and 18.9 during the mid-1960s. India's current 5-year plan has set a goal of a birth rate of 30/1000 population by 1985 and "replacement-level" fertility--about 2.3 births per woman--by 1996. The acceleration in India's population growth has come mainly in the past 3 decades and is due primarily to a decline in mortality that has markedly outstripped the fertility decline. The Janata Party which assumed government leadership in March 1977 did not dismantle the family planning program, but emphasis was shifted to promote family planning "without any compulsion, coercion or pressures of any sort." The policy statement stressed that efforts were to be directed towards those currently underserved, mainly in rural areas. Hard targets were rejected. Over the 1978

  6. Epidemiology Characteristics of Constipation for General Population, Pediatric Population, and Elderly Population in China

    Directory of Open Access Journals (Sweden)

    Huikuan Chu

    2014-01-01

    Full Text Available Objective. To acquire more data about the epidemiologic characteristics of constipation in different kinds of populations in China. Methods. Using “constipation” and “China” as search terms; relevant papers were searched from January 1995 to April 2014. Data on prevalence, gender, diagnostic criteria, geographical area, educational class, age, race, and physician visit results were extracted and analyzed. Results. 36 trials were included. Prevalence rates of constipation in elderly population (18.1% and pediatric population (18.8% were significantly higher than that in general population (8.2%. Prevalence of constipation defined by non-Rome criteria was higher than that by Rome criteria in general population. Prevalence rates of constipation were different for different geographical area. People with less education were predisposed to constipation. In pediatric population, prevalence of constipation was the lowest in children aged 2–6 years. Prevalence of constipation in ethnic minorities was higher than that in Han people. People with constipation were predisposed to FD, haemorrhoid, and GERD. Only 22.2% patients seek medical advice in general population. Conclusions. In China, prevalence of constipation was lower compared with most of other countries. The factors including female gender, diagnostic criteria, geographical area, age, educational class, and race seemed to have major effects on prevalence of constipation.

  7. Epidemiology Characteristics of Constipation for General Population, Pediatric Population, and Elderly Population in China

    Science.gov (United States)

    Chu, Huikuan; Zhong, Likun; Li, Hai; Zhang, Xiujing; Zhang, Jingzhi; Hou, Xiaohua

    2014-01-01

    Objective. To acquire more data about the epidemiologic characteristics of constipation in different kinds of populations in China. Methods. Using “constipation” and “China” as search terms; relevant papers were searched from January 1995 to April 2014. Data on prevalence, gender, diagnostic criteria, geographical area, educational class, age, race, and physician visit results were extracted and analyzed. Results. 36 trials were included. Prevalence rates of constipation in elderly population (18.1%) and pediatric population (18.8%) were significantly higher than that in general population (8.2%). Prevalence of constipation defined by non-Rome criteria was higher than that by Rome criteria in general population. Prevalence rates of constipation were different for different geographical area. People with less education were predisposed to constipation. In pediatric population, prevalence of constipation was the lowest in children aged 2–6 years. Prevalence of constipation in ethnic minorities was higher than that in Han people. People with constipation were predisposed to FD, haemorrhoid, and GERD. Only 22.2% patients seek medical advice in general population. Conclusions. In China, prevalence of constipation was lower compared with most of other countries. The factors including female gender, diagnostic criteria, geographical area, age, educational class, and race seemed to have major effects on prevalence of constipation. PMID:25386187

  8. Canada's population: growth and dualism.

    Science.gov (United States)

    Beaujot, R P

    1978-04-01

    In Canada the current 1.3% population growth rate is causing some concern. Those concerned argue that such a rate of growth in combination with high levels of consumption could jeopardize the country's resource base and its comfortable style of living. Many Canadians are questioning high levels of immigration, for now that the fertility level is below replacement level, net immigration contributes substantially to population growth (over 1/3 in 1976). The growing proportion of non-Europeans among recent immigrants is causing resentment, and, in a tight job market, immigrants are regarded as threats to the World War 2 baby boom cohort who are now at working ages. The baby boom generation also puts stress on housing and health services, and it will increase the need for pension checks as it ages. Although French fertility is no longer high and immigration is no longer dominated by the British, the French group's 200-year struggle to preserve its identity continues on in the current effort of the Quebec government to enforce the use of French language by law within that province. Geography and climate dictate another demographic fact that divides the country and pervades its history. In addition to intense regionalism, uneven population distribution is responsible for 2 other concerns: the rapid growth of several already large cities and depopulation of many small communities. Focus in this discussion is on Canada's population growth in the past and as projected for the future, historical and current fertility, mortality and immigration trends, the search for a new immigration policy, the impact of the baby boom generation on the population's age structure and the problems this creates, and recent shifts in population distribution and in the country's ethnic and linguistic makeup. The population policy proposals evolved thus far involve to a great extent the use of immigration as a lever for achieving given population objectives.

  9. Population and Employment in China

    OpenAIRE

    Keyfitz, N.

    1982-01-01

    China's effectiveness in population control can be credited to the direct line of command through party and administrative cadres that extends from the leadership in Beijing down to the production team in a distant rural commune. The reason that the administrative machine has devoted so much attention to population control is twofold: the perceived limits of the natural environment, as indicated by slowness of growth of food supplies, and the difficulty of arranging productive employment for ...

  10. Population growth and infant mortality

    OpenAIRE

    Fabella, Christina

    2008-01-01

    The relationship between population growth and economic outcomes is an issue of great policy significance. In the era of the Millennium Development Goals, poverty and its correlates have become the compelling issues. Economic growth may not automatically translate into reductions in poverty and its correlates (may not trickle down) if income distribution is at the same time worsening. We therefore investigate the direct effect of population growth on infant mortality for various income catego...

  11. Regional Population Projections for China

    OpenAIRE

    Toth, F.L.; Cao, G.-Y.; Hizsnyik, E.

    2003-01-01

    Considering the size and the regional diversity of China, a prudent analysis of many economic and policy issues needs to consider the regional differences in climate, soil, water, and other natural resource endowments, population density, and social and economic development. Future-oriented multi-regional assessments require regionally detailed scenarios. A key component of such scenarios is the evolution of the population in different regions. For studies of land-use change and agriculture, ...

  12. Indonesia: population central to development.

    Science.gov (United States)

    1994-05-01

    The Indonesian representative to the 50th session of the Economic and Social Commission for Asia and the Pacific (ESCAP) reiterated the issue of population as being central to sustainable development. Indonesia recognizes that quality of life, which can be improved with education, health, skills, productivity, self reliance, and resiliency, has an impact on the process of development. Without quality improvements, large numbers of people become a burden. Population programs must aim to reduce population growth rates simultaneously with enhancing the quality of life. Women's improvement in education, health, and employment opportunities must be accomplished because of women's important role in national development. The goals of sustainable development are to maintain a balance between human needs and desires of the population and available resources and the environment. Sustainable development is necessary for present and future generations. The Fourth Asian and Pacific Population Conference was held in Bali in August 1992, at which time the Bali Declaration was affirmed. At the January 1994 meeting of officials regarding the implementation of the Bali Declaration held in Bangkok, Thailand, the Indonesian representative stressed the importance of the vigorous involvement of the ESCAP secretariat in planning and implementing population programs in the region. Recommendations included in the Bali Declaration are related to the issues being addressed at the International Conference on Population and Development to be held in Cairo in September 1994. The secretariat was also asked by the Indonesian representative to disseminate information on the implementation of the Bali Declaration through regular publications and other appropriate venues. Comprehensive data collection and information systems were needed on the links between population, development, and resources.

  13. Population, education and sustainable development.

    Science.gov (United States)

    Johnston, T

    1992-12-01

    The author examines the interrelationships between population growth and education, with a focus on Sub-Saharan Africa. "The gross body of evidence suggests that for all developing regions (and for sub-saharan Africa specifically) rapid population growth deleteriously impacts upon the quantity and quality of schooling. In a reciprocal fashion, the variables which underpin rapid and differential growth (fertility, mortality and migration) are themselves influenced by quantum of formal schooling and by other educational processes." excerpt

  14. Environmental pollution and population policies.

    Science.gov (United States)

    1980-04-01

    There is a growing recognition in Malaysia of the interrelationship between population growth, population policies, development policies, and environmental pollution. In Malaysia, with a current population of 13,250,000 and an annual growth rate of 2.4%, economic development is leading to large scale deforestation which in turn is altering climatic conditions, reducing water supplies, and increasing erosion. According to estimates 750,000 acres of jungle were cleared in the last 10 years. Industrial wastes and domestic sewage discharged into rivers and lakes is endangering marine life and padilands. This is a serious problem, since 70% of the Malaysian population derives the bulk of their protein intake from marine life. Noise and carbon monoxide pollution in urban areas is increasing due to the 15% annual increase in the number of vehicles in the country. These dangers need to be taken into account as continuing efforts are made to increase industrialization in order to provide jobs for the 350,000 unemployed and underemployed youth in the country. Fortunately, government officials in Malaysia are giving consideration to energy, water and oil conservation in formulating development plans and are becoming increasingly aware that population growth and population policies have a direct impact on development planning and environmental pollution.

  15. Global fertility and population trends.

    Science.gov (United States)

    Bongaarts, John

    2015-01-01

    Over the past several decades, the world and most countries have undergone unprecedented demographic change. The most obvious example of this change is the rise in human numbers, and there are also important trends in fertility, family structure, mortality, migration, urbanization, and population aging. This paper summarizes past trends and projections in fertility and population. After reaching 2.5 billion in 1950, the world population grew rapidly to 7.2 billion in 2013 and the projections expect this total to be 10.9 billion by 2100. World regions differ widely in their demographic trends, with rapid population growth and high fertility continuing in the poorest countries, particularly in sub-Saharan Africa, while population decline, population aging, and very low fertility are now a key concern in many developed countries. These trends have important implications for human welfare and are of interest to policy makers. The conclusion comments briefly on policy options to address these adverse trends. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. Evolutionary dynamics in structured populations

    Science.gov (United States)

    Nowak, Martin A.; Tarnita, Corina E.; Antal, Tibor

    2010-01-01

    Evolutionary dynamics shape the living world around us. At the centre of every evolutionary process is a population of reproducing individuals. The structure of that population affects evolutionary dynamics. The individuals can be molecules, cells, viruses, multicellular organisms or humans. Whenever the fitness of individuals depends on the relative abundance of phenotypes in the population, we are in the realm of evolutionary game theory. Evolutionary game theory is a general approach that can describe the competition of species in an ecosystem, the interaction between hosts and parasites, between viruses and cells, and also the spread of ideas and behaviours in the human population. In this perspective, we review the recent advances in evolutionary game dynamics with a particular emphasis on stochastic approaches in finite sized and structured populations. We give simple, fundamental laws that determine how natural selection chooses between competing strategies. We study the well-mixed population, evolutionary graph theory, games in phenotype space and evolutionary set theory. We apply these results to the evolution of cooperation. The mechanism that leads to the evolution of cooperation in these settings could be called ‘spatial selection’: cooperators prevail against defectors by clustering in physical or other spaces. PMID:20008382

  17. "Population policy in developed countries.".

    Science.gov (United States)

    Baldwin, G B

    1973-12-01

    Bernard Berelson's book, "Population Policy in Developed Countries," provides a report on population policy in the developed world as of the early 1970s, covering countries with 20 million population or over, and 11 countries of special interest. There are chapters by national experts from 25 countries. A developed country is defined as industrialized, healthier, better educated, better off, more modernized, and distinguished by low fertility. This does not mean that population growth in these countries has yet fallen to zero or lower, but in 7 or 8 countries, population is expected to stabilize in a decade or so unless recent fertility trends reverse themselves or are offset by immigration. The conclusions drawn from the 25 country reports are summarized, and highlights of the demographic situation and policies in 12 of the countries are presented, Berelson is cautious in predicting the future shape of population policy in the developed world. There have been too many policy changes in the past to be confident of the future. He feels, however, that more and more people are likely to accept the goal of replacement, up to replacement in some countries and down to replacement in others.

  18. The Soviet Union and population: theory, problems, and population policy.

    Science.gov (United States)

    Di Maio, A J

    1980-04-01

    Until the important public dialog on 3rd World population issues began in the Soviet Uuion in 1965, ideological limitations and bureaucratic interests prevented policy makers from recognizing the existence of a world of national "population problem." Since then, freer discussions of the Soviet Union's surprising decline in birthrate and labor shortages have led to serious policy questions. Conflicting policy goals, however, have resulted in only modest pronatalist policies. The Soviet population problem is a result of interregional disparities in population growth rates between the highly urbanized Soviet European populations with low birth rates and the least urbanized Central Asians with dramatically higher birth rates. As a result, these essentially Muslim people will provide the only major increases in labor resources and an increasing percentage of Soviet armed forces recruits. Policy planners are thus faced with difficult options. Current policies stressing technological transfers from the west and greater labor productivity, however, are unlikely to solve further labor shortages and regional imbalances. Ultimately, nonEuropana regions will be in an improved bargaining position for more favorable nationwide economic policies and for a greater role in policy planning.

  19. Population growth and its implications

    Directory of Open Access Journals (Sweden)

    Badii, M. H.

    2005-01-01

    Full Text Available Human populations have grown at an unprecedented rate over the past three centuries. By 2001, the world population stood at 6.2 billion people. If the current trend of 1.4 % per year persists, the population will double in 51years. Most of that growth will occur in the less developed countries of Asia, Africa, and Latin America. There is a serious concern that the number of humans in the world and our impact on the environment will overload the life support systems of the earth. The crude birth rate is the number of births in a year divided by the average population. A more accurate measure of growth is the general fertility rate, which takes into account the age structure and fecundity of the population. The crude birth rate minus the crude death rate gives the rate of natural increase. When this rate reaches a level at which people are just replacing themselves, zero population growth is achieved. In the more highly developed countries of the world, growth has slowed are even reversed in recent years so that without immigration from other areas, population would be declining. The change from high birth and death rates that accompanies in industrialization is called a demographic transition. Many developing nations have already begun this transition. Death rates have fallen, but birth rates remain high. Some demographers believe that as infant mortality drops and economic development progresses so that people in these countries can be sure of secure future, they will complete the transition to a stable population or a high standard living. While larger populations bring many problems, they also may be a valuable resource of energy, intelligence, and enterprise that will make it possible to overcome resource limitation problems. A social just view argues that a more equitable distribution of wealth might reduce both excess population growth and environmental degradation. We have many more options now for controlling fertility than were available

  20. Philippine population policy: quo vadis?

    Science.gov (United States)

    Carino, L V

    1994-06-01

    In the Philippines, debate engendered in 1994 by the introduction of a antiabortifacient bill written in such broad language that it would outlaw most contraceptives recalls earlier debates on population policy and shows that not much has changed on the surface: the US is still providing funds, the Catholic Church is still opposing program advocates, and the population is still growing. The history of family planning (FP) in the Philippines developed during five periods: 1) prior to 1969 FP was offered only by private organizations; 2) from 1969 to 1974, the government began to incorporate FP as a policy; 3) from 1974 to 1986, FP and population issues were considered part of total development; 4) from 1986-1992, FP was subsumed under maternal and child health; and 5) from 1992 to the present, policy was enacted to balance population concerns with resources and development. This newsletter considers the first two stages. The written code of one of the precolonization self-governing indigenous peoples linked the number of permitted wives to population size and limited (through infanticide) the number of children a poor couple could have. During the 1960s, the Ford Foundation created a Population Institute, a protestant group established a countrywide Planned Parenthood Movement, and a Catholic Family Planning Association was formed. The public sector became involved when the Health Department of Manila sponsored a training seminar on FP. During the second stage, President Marcos began increasingly to support a government policy facilitating FP. By 1970, FP was an announced policy of his government. The Population Commission was to suffer many administrative changes during the period, but the emphasis on fertility reduction remained within a basic framework of a policy which gave every couple the right to choose their method of FP. By the end of 1974, more than 20 organizations had become involved in FP and more than 2000 clinics provided services. (This survey is

  1. Focus on managing population growth.

    Science.gov (United States)

    Brown, S

    1995-01-01

    For the past 4 decades, the world's population growth has threatened to outstrip the planet's ability to sustain it. According to recent projections, an end to the growth of world population is finally in sight. Dr. Joseph van Arendonk, deputy executive director of the United Nations Population Fund, told an international press conference that population growth is likely to begin falling before the mid-21st century. Currently, some 87 million couples worldwide wish to use contraception but have no access to services. Van Arendonk argued that 4% of overseas aid set aside for population programs would satisfy this unmet need. He also predicted that the average family size in developing countries would stabilize at 2.1 children within the next 55 years if these needs were met. This would still mean a global population of 10 billion in the year 2050, rising to a plateau of 11.6 billion within the following century. In developing countries fertility rates fell from 6.1 to 3.3 children per woman between the mid-1960s and the mid-1980s, while use of contraception increased from 10% to 50%. However, contraceptive users in the developing world must increase from 446 million in 1994 to 603 million in 2005 to keep population growth within such projected limits. The costs of providing the contraception will increase from US $528 million to US $752 million. The contraceptive needs of 603 million users in 2005 will require: 196 million sterilizations, 436 million IUD insertions, 898 million injectables, 12.3 billion cycles of OCs, and 55 billion condoms. To this end, IPPF plans greater accessibility of services, a wider range of effective methods, and the involvement of the male partner.

  2. Epidemiology Characteristics of Constipation for General Population, Pediatric Population, and Elderly Population in China

    OpenAIRE

    Chu, Huikuan; Zhong, Likun; Li, Hai; Zhang, Xiujing; Zhang, Jingzhi; Hou, Xiaohua

    2014-01-01

    Objective. To acquire more data about the epidemiologic characteristics of constipation in different kinds of populations in China. Methods. Using “constipation” and “China” as search terms; relevant papers were searched from January 1995 to April 2014. Data on prevalence, gender, diagnostic criteria, geographical area, educational class, age, race, and physician visit results were extracted and analyzed. Results. 36 trials were included. Prevalence rates of constipation in elderly population...

  3. Population growth and economic growth.

    Science.gov (United States)

    Narayana, D L

    1984-01-01

    This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize

  4. MPS views on population growth.

    Science.gov (United States)

    1997-09-01

    This article features the different views of Parliament members concerning the need in the reduction of population growth for development sustenance. Population growth would lead to environmental degradation, malnutrition, diseases, and high incidence of poverty. Furthermore, social problems arise like teenage pregnancies, and abuse of young girls. Suggestions on curtailing this problem as suggested by some of the parliament members includes educating people on issues of migration, family planning and reproductive health. Other members suggested on family planning legislation, like in the case of China where population explosion exists. Further, members thought that advocacy for population control such as condom usage targeting to couples having large families should be catered. However, this was denounced by some members as a failure and should not be sanctioned at large family couples but rather to husband with several wives. Finally, a compromised view was directed on population management with poverty alleviation involving the provision of amenities such as water, electricity, good roads, potable water, and income generating activities.

  5. Political economy of population growth.

    Science.gov (United States)

    Mehta, S; Mehta, H S

    1987-01-01

    Tracing the origin of political economy as a class-science, this paper focuses on the political economy of population growth. Exposing the limitations of Malthusian ideas and their invalidity even for the capitalist economies, it discusses the subsequent revival of the Malthusian model during the period of de-colonization and the misinterpretation of the relationship between population growth and development in the developing and developed countries. Taking India, China, and Japan as some case studies, the paper examines the relationship between birth rate levels and some correlates. It elaborates on the Indian experience, emphasizing the association of population growth with poverty and unemployment and lays bare some of the hidden causes of these phenomena. The authors examine some interstate variations in India and identify constraints and prospects of the existing population policy. The paper proposes outlines of a democratic population policy as an integral part of India's development strategy which should recognize human beings not simply as consumers but also as producers of material values. It pleads for 1) restructuring of property relations; 2) bringing down the mortality rates and raising of the literacy levels, especially among females; and 3) improving nutritional levels, as prerequisites for bringing down birth rates.

  6. Population dynamics in variable environments

    CERN Document Server

    Tuljapurkar, Shripad

    1990-01-01

    Demography relates observable facts about individuals to the dynamics of populations. If the dynamics are linear and do not change over time, the classical theory of Lotka (1907) and Leslie (1945) is the central tool of demography. This book addresses the situation when the assumption of constancy is dropped. In many practical situations, a population will display unpredictable variation over time in its vital rates, which must then be described in statistical terms. Most of this book is concerned with the theory of populations which are subject to random temporal changes in their vital rates, although other kinds of variation (e. g. , cyclical) are also dealt with. The central questions are: how does temporal variation work its way into a population's future, and how does it affect our interpretation of a population's past. The results here are directed at demographers of humans and at popula­ tion biologists. The uneven mathematical level is dictated by the material, but the book should be accessible to re...

  7. Global earthquake fatalities and population

    Science.gov (United States)

    Holzer, Thomas L.; Savage, James C.

    2013-01-01

    Modern global earthquake fatalities can be separated into two components: (1) fatalities from an approximately constant annual background rate that is independent of world population growth and (2) fatalities caused by earthquakes with large human death tolls, the frequency of which is dependent on world population. Earthquakes with death tolls greater than 100,000 (and 50,000) have increased with world population and obey a nonstationary Poisson distribution with rate proportional to population. We predict that the number of earthquakes with death tolls greater than 100,000 (50,000) will increase in the 21st century to 8.7±3.3 (20.5±4.3) from 4 (7) observed in the 20th century if world population reaches 10.1 billion in 2100. Combining fatalities caused by the background rate with fatalities caused by catastrophic earthquakes (>100,000 fatalities) indicates global fatalities in the 21st century will be 2.57±0.64 million if the average post-1900 death toll for catastrophic earthquakes (193,000) is assumed.

  8. Popullution: A Position Paper on Population.

    Science.gov (United States)

    Durner, Mary Beth

    This position paper presents an interdisciplinary approach to the study of population. Six main sections are included in the paper: Introduction, The Growth of the Human Population, The Psychological Effects of Population Growth, Overpopulated America, Myths Concerning Population Growth and Control, and Population Education. Section 1, an…

  9. Analysis of Population Dynamics in World Economy

    OpenAIRE

    Martin, Gress

    2011-01-01

    Population dynamics is an important topic in current world economy. The size and growth of population have an impact on economic growth and development of individual countries and vice versa, economic development influences demographic variables in a country. The aim of the article is to analyze historical development of world population, population stock change and relations between population stock change and economic development.

  10. Future directions in population health.

    Science.gov (United States)

    Hancock, T

    1999-01-01

    The long-term health of the population will be influenced by a number of major forces in the next century. In this brief review, particular emphasis is placed on environmental and economic forces. Major global environmental changes include climate change and global warming, resource depletion, ecotoxicity and reduced biodiversity. We do not yet know the impact on longevity of lifetime exposure to a mix of persistent toxic chemicals in our environment, since it has only been widespread in the past 40-50 years. The health impacts of global warming are only just beginning to be understood and could be profound. But perhaps the most profound threat to population health is economic growth, to the extent that it undermines environmental and social sustainability. We need a new form of capitalism, one that simultaneously increases environmental, social, economic and human capital, if population health is to be maintained in the 21st century.

  11. Cancer patterns in Inuit populations

    DEFF Research Database (Denmark)

    Melbye, M.; Friborg, Jeppe Tang

    2008-01-01

    Inuit people inhabit the circumpolar region, with most living in Alaska, northwest Canada, and Greenland. Although malignant diseases were believed to be almost non-existent in Inuit populations during the beginning of the 20th century, the increasing life expectancy within these populations showed...... a distinct pattern, characterised by a high risk of Epstein-Barr virus-associated carcinomas of the nasopharynx and salivary glands, and a low risk of tumours common in white populations, including cancer of the prostate, testis, and haemopoietic system. Both genetic and environmental factors seem...... to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet...

  12. Keynes, population, and equity prices.

    Science.gov (United States)

    Tarascio, V J

    1985-01-01

    Keynes in 1937 examined the phenomenon of the Great Depression from a longrun perspective in contradiction to the "General Theory," where the focus was on the shortrun. "Some Economic Consequences of a Declining Population," Keynes' article, reveals the context in which the "General Theory" was written. In the "General Theory," the focus is on short-term fluctuations, i.e., business cycles, but Keynes fails to provide any theoretical explanation as to why the depression of the 1930s was so severe and intractable. In the 1937 article, the depression is seen as the result of the combined effects of a decline in longrun growth due to population growth decline and a shortrun cyclical decline, together producing severe economic consequences. What is important for the purposes of this discussion is the implication, within the context of the 1937 article, that not only was the stock market crash of 1929 related to population change (with its accompanying collapse in expectations) but that, in general, changes in the rate of growth of population are accompanied by stock price movements in the same direction. The remainder of the discussion is devoted to a simple empirical test of this relationship. The data used are population size (POP), defined as the total residential population in the US from 1870-1979, and the Standard and Poor 500 Stock index (SP) for the corresponding 109-year period. In addition, a 3rd series was constructed, a price deflated Standard and Poor index (RSP) with a base period of 1870, to account for possible inflationary distortion of the index. The empirical results do not invalidate the hypothesis that population growth rates affect equity markets. In fact, there seems to be strong evidence that they are related in a manner suggestive of Keynes' intutition, namely, that the stock market crash of 1929 was due to factors more fundamental than those often perceived from a shortrun perspective. According to Keynes (1937), population is the most

  13. Population fluctuation in phytophagous insects

    Energy Technology Data Exchange (ETDEWEB)

    Redfearn, A.; Pimm, S.L. (Oak Ridge National Laboratory, TN (United States))

    1994-06-01

    We examined how community interactions affect year-to-year population variability in three groups of phytophagous insects: British aphids and moths, and Canadian moths. We first examined how the number of host plant species on which a given phytophagous insect species feeds affects its population variability. Specialist insect species showed a weak tendency to be more variable than generalist species. We then examined how the number of species of parasitoids from which a given phytophagous insects species suffers affects its population variability. Species that are host to few parasitoid species showed a weak tendency to be more variable than species with many parsitoid species. These relationships also depend on other aspects of the life histories of the phytophagous insect species.

  14. Complicated grief in Aboriginal populations.

    Science.gov (United States)

    Spiwak, Rae; Sareen, Jitender; Elias, Brenda; Martens, Patricia; Munro, Garry; Bolton, James

    2012-06-01

    To date there have been no studies examining complicated grief (CG) in Aboriginal populations. Although this research gap exists, it can be hypothesized that Aboriginal populations may be at increased risk for CG, given a variety of factors, including increased rates of all-cause mortality and death by suicide. Aboriginal people also have a past history of multiple stressors resulting from the effects of colonization and forced assimilation, a significant example being residential school placement. This loss of culture and high rates of traumatic events may place Aboriginal individuals at increased risk for suicide, as well as CG resulting from traumatic loss and suicide bereavement. Studies are needed to examine CG in Aboriginal populations. These studies must include cooperation with Aboriginal communities to help identify risk factors for CG, understand the role of culture among these communities, and identify interventions to reduce poor health outcomes such as suicidal behavior.

  15. Rapid population increase in an introduced muskox population, West Greenland

    Directory of Open Access Journals (Sweden)

    Carsten Riis Olesen

    1993-10-01

    Full Text Available In 1962 and 1965, 27 (13 and 14 muskox yearlings were translocated from East Greenland (71°N to the Angujaartorfiup Nunaa range in West Greenland (67°N. Angujaartorfiup Nunaa is a 6600 km2 icefree, continental area where caribou are indigenous. The climate is strictly continental with a minimum of precipitation but with abundant vegetation. Aerial surveys in 1990 documented that the muskox population has increased to 2600 heads despite quota-based harvesting since 1988. The annual quota was 200, 300 and 400 for 1988, 1989 and 1990, respectively. Distribution of muskoxen shows a significant preference for low altitude habitats southeast of Kangerlussuaq Airport and around Arnangarnup Qoorua (Paradise valley. Annual population increment averages 30% and the calf crop is around 24% of the population. Yearling recruitment in the population reveals that calf mortality during winter is very limited. About half of the 1-year-old females are served and they eventually give birth to their first calf when they turn 2 years old. With half of the 2-year-old females reproducing, the calf/cow ration ranges between 0.9 and 1.0.

  16. Population and Health in Developing Countries: Population, Health ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2002-01-10

    Jan 10, 2002 ... For the one billion people living in the world's poorest countries, where the burden of disease is highest, those who are born or who die are still not counted. The health profile of these populations is akin to an iceberg: the bulk of reliable data remains hidden. This great information void is a major, ...

  17. Population pressures in Latin America.

    Science.gov (United States)

    Merrick, T W; Kent, M M; Van Der Tak, J; Von Cube, A

    1986-07-01

    In 1950 Latin America's population of 165 million was on a par with the 166 million of North America. 2 decades of growth at nearly 3% a year pushed the total to 405 million in 1985, vs. 264 million in North America. Despite substantial fertility declines since the 1960s, continued growth is ensured by the demographic momentum built into the region's large and youthful population bases. UN medium projections put the 2025 total at 779 million, compared to 345 million in North America. This Bulletin examines the main demographic changes in Latin America since World War II and their links to economic and social changes in the region as well as their implications for international and social relations. The post World War II population surge was accompanied by massive rural-ruban and international migration, rapid urbanization, large labor shifts out of agriculture into industry and services, increased education for both men and women, and higher labor force participation for females. The rural exodus was spurred by extreme land tenure inequalities and the urban bias of postwar industrialization. The labor-saving bias of this industrialization forced exploding city populations to turn to the informal sector for jobs. Population pressures on city services and housing as well as jobs have been further exacerbated by overconcentration in a few large cities and economic downturns of the 1980s. Recent fertility declines seem to be the result of both increased access to family planning and the economic and social pressures posed by the gap between young adults' aspirations and their ability to realize them. Population and economic pressures could induce faster fertility declines than now projected but in the short run are likely to mean more employment problems, continued rapid urban growth, and even larger international immigration flows within the hemisphere, particularly to the US.

  18. [Population growth and the environment].

    Science.gov (United States)

    Hogan, D J

    1991-01-01

    The impact of population growth on the enviornment has been extensively researched; it consists of the depletion of resources (agricultural land absorbed by urban expansion, loss of soils, desertification, loss of biodiversity, less availability of minerals, dwindling of petroleum reserves) and the degradation of natural resources (air and water pollution). For politicians, journalists, and environmentalists, population growth is identified as the principal villain, which is a unidirectional and negative opinion. Demography is supposed to examine the negative and positive effects of the environment-population relationship; however, it is postulated that there has not been much produced in the last 2 centuries in this area. Examination of the research literature does not indicate any view that transcends the Malthusian vision, although a few empirical studies exist (Hogan, 1989). Durham (1979) identified the replacement of subsistence agriculture by export-oriented agriculture as the key factor in overpopulation in El Salvador and Honduras that led to migrations and international conflicts. Tudela (1987) related a similar process in the Mexican state of Tabasco, where a period of malnutrition was accompanied by the expansion of export agriculture and nutritional improvements emanated only from recapturing subsistence agriculture. Fearnside (1986) researched the dynamics of the occupation and destruction of Amazonia. However, Kahn and Simon went further and denied the existence of real environmental problems: population is the ultimate resource, and the more minds, the more good ideas and solutions for any problem. However, in all these cases of pure or modified Malthusianism the relation of population/resources is reduced to a unidimensional relationship; and fertility, mortality, migration, marriage, and age structure receive little attention. A prime candidate for the attention of population specialists should be migration and patterns of settlement and their

  19. Growing population causes of unemployment.

    Science.gov (United States)

    1995-01-01

    At the March, 1995, International Meeting on Population and Social Development in Copenhagen, during the session on unemployment, underemployment, and population it was stated that the problem of employment was the extent to which a nation's labor supply was not matched by labor demand or job opportunities. Population was thus a supply factor, and the country's economic situation was a demand factor. The demographic variables that were considered important in the supply of labor were: a) the size and rate of growth of the population, which was a function of the birth rate, the death rate, and migration; and b) the age structure of the population, which was also a product of the rate of growth of the population and its distribution. An imbalance between the supply of labor and the demand for it gave rise to unemployment and underemployment. The vicious cycle generated by a high dependency burden associated with a young age-structure led to low savings and investments, which in turn led to low economic growth and a low standard of living. This produced high fertility rates, which in turn heightened the dependency burden perpetuating the cycle. This vicious cycle could be broken at only two points: at the high fertility stage, primarily by introducing family planning programs; and at the stage of low economic growth, by adopting policies to accelerate economic growth. To be successful, however, both actions had to be pursued simultaneously. Numerous participants emphasized the global nature of the issue of unemployment and underemployment; the effects of international competition and restrictive trade policies on employment opportunities. The growing disparity between North and South had created a social injustice between countries. Several participants called for more humane policies that favored democracy and promoted human development, and asked for assistance to help create an enabling environment for social and economic development.

  20. Population change and the environment.

    Science.gov (United States)

    1989-01-01

    The environmental and natural resource problems that afflict most countries of the Asian and Pacific region are caused by human activities, often arising from the needs of growing populations for land to cultivate subsistence crops. These include the farming of marginal land; insufficient fallow periods; the clearing of forest land for agriculture and the felling of trees for firewood and timber. Water pollution, air pollution, deforestation and desertification are related to human activities. One of the priorities for population and development planning in the region will be action-oriented research into the linkages, to guide national and regional development policies. Both population and environmental concerns must be integrated into social and economic development plans in order for development to be sustainable. To achieve these goals, rapid population growth must be slowed and eventually stabilized, while strategies on optimal population distribution should be formulated. Concomitantly, environmental conditions must be maintained or improved through reversing deforestation and erosion in major watersheds; checking the spread of deserts; introducing sustainable water management; reducing acidification and hazardous waste; developing and introducing environmentally safe industrial processes; eliminating hunger through sustainable agriculture; finding new and renewable sources of energy and increasing energy efficiency; and protecting animal and plant species and preventing further loss. To avoid the possible negative consequences, balanced development in an integrated fashion is called for. As far as environmental problems are concerned, there is a growing need for the planning mechanism to take demographic variables into account in a more integrated way than has been done in the past. For purposes of environmental and population planning, a longer-term approach should be taken in addition to the five-year plans.

  1. Burst Populations and Detector Sensitivity

    Science.gov (United States)

    Band, David L.

    2003-01-01

    The F(sub T) (peak bolometric photon flux) vs. E(sub p) (peak energy) plane is a powerful tool to compare the burst populations detected by different detectors. Detector sensitivity curves in this plane demonstrate which burst populations the detectors will detect. For example, future CZT-based detectors will show the largest increase in sensitivity for soft bursts, and will be particularly well- suited to study X-ray rich bursts and X-ray Flashes. Identical bursts at different redshifts describe a track in the F(sub T)-E(sub p) plane.

  2. Structure of African elephant populations

    DEFF Research Database (Denmark)

    Siegismund, H R; Arctander, P

    1996-01-01

    The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion that there was a ......The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion...

  3. ISLSCP II Global Population of the World

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Global Population of the World (GPW) translates census population data to a latitude-longitude grid so that population data may be used in...

  4. ISLSCP II Global Population of the World

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population of the World (GPW) translates census population data to a latitude-longitude grid so that population data may be used in cross-disciplinary...

  5. The Why and How of Population Education

    Science.gov (United States)

    Seffrin, John R.

    1975-01-01

    Discusses the importance of instructional programs concerning population education and describes population growth in the United States, the biological reasons for the overpopulation problem, and the role of the health educator in population education. (BD)

  6. Global Population Density Grid Time Series Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population Density Grid Time Series Estimates provide a back-cast time series of population density grids based on the year 2000 population grid from SEDAC's...

  7. Global Population Count Grid Time Series Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population Count Grid Time Series Estimates provide a back-cast time series of population grids based on the year 2000 population grid from SEDAC's Global...

  8. Flood trends and population dynamics

    Science.gov (United States)

    Di Baldassarre, G.

    2012-04-01

    Since the earliest recorded civilizations, such as those in Mesopotamia and Egypt that developed in the fertile floodplains of the Tigris and Euphrates and Nile rivers, humans tend to settle in flood prone areas as they offer favorable conditions for economic development. However, floodplains are also exposed to flood disasters that might cause severe socio-economic and environmental damages not to mention losses of human lives. A flood event turns to be a disaster when it coincides with a vulnerable environment exceeding society's capacity to manage the adverse consequences. This presentation discusses the link between hydrological risk and population change by referring to the outcomes of scientific works recently carried out in Africa and Europe. More specifically, it is shown that the severity of flood disasters, currently affecting more than 100 million people a year, might be seriously exacerbated because of population change. In fact, flood exposure and/or vulnerability might increase because of rapid population growth (and its spatial and temporal dynamics, e.g. urbanization) in the African continent and because of population ageing in many European countries. Lastly, timely and economically sustainable actions to mitigate this increasing hydrological risk are critically evaluated.

  9. Population consequences of aggregative movement

    Science.gov (United States)

    Peter Turchin

    1989-01-01

    Gregarious behaviour is an important factor influencing survival and reproduction of animals, as well as population interactions. In this paper I develop a model of movement with attraction or repulsion between conspecifics. To facilitate its use in empirical studies, the model is based on experimentally measurable features of individual behaviour.

  10. Fisher population and landscape genetics

    Science.gov (United States)

    Michael Schwartz; Joel Saunder; Kristine L. Pilgrim; Ray Vinkey; Michael K. Lucid; Sean Parks; Nathan Albrecht

    2013-01-01

    This talk provides a population and landscape genetic overview of fishers in Idaho and Montana. We start by discussing some of our initial findings using mitochondrial DNA (Vinkey et al. 2006, Schwartz 2007, Knaus et al. 2011). On balance these results demonstrate the uniqueness of a native haplotype that persisted in the Bitterroot-Selway Ecosystem. They also show the...

  11. Population, Poverty, and Climate Change

    OpenAIRE

    Monica Das Gupta

    2014-01-01

    The literature is reviewed on the relationships between population, poverty, and climate change. While developed countries are largely responsible for global warming, the brunt of the fallout will be borne by the developing world, in lower agricultural output, poorer health, and more frequent natural disasters. Carbon emissions in the developed world have leveled off, but are projected to ...

  12. Measuring cancer in indigenous populations.

    Science.gov (United States)

    Sarfati, Diana; Garvey, Gail; Robson, Bridget; Moore, Suzanne; Cunningham, Ruth; Withrow, Diana; Griffiths, Kalinda; Caron, Nadine R; Bray, Freddie

    2018-02-15

    It is estimated that there are 370 million indigenous peoples in 90 countries globally. Indigenous peoples generally face substantial disadvantage and poorer health status compared with nonindigenous peoples. Population-level cancer surveillance provides data to set priorities, inform policies, and monitor progress over time. Measuring the cancer burden of vulnerable subpopulations, particularly indigenous peoples, is problematic. There are a number of practical and methodological issues potentially resulting in substantial underestimation of cancer incidence and mortality rates, and biased survival rates, among indigenous peoples. This, in turn, may result in a deprioritization of cancer-related programs and policies among these populations. This commentary describes key issues relating to cancer surveillance among indigenous populations including 1) suboptimal identification of indigenous populations, 2) numerator-denominator bias, 3) problems with data linkage in survival analysis, and 4) statistical analytic considerations. We suggest solutions that can be implemented to strengthen the visibility of indigenous peoples around the world. These include acknowledgment of the central importance of full engagement of indigenous peoples with all data-related processes, encouraging the use of indigenous identifiers in national and regional data sets and mitigation and/or careful assessment of biases inherent in cancer surveillance methods for indigenous peoples. Copyright © 2018. Published by Elsevier Inc.

  13. Better Reporting of Population Issues.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter and Forum, 1990

    1990-01-01

    Presented are the focus and the annotated issues from a workshop on new perspectives in population education for 19 Pacific Island journalists, both print and broadcast, from government and nongovernment agencies. The regional workshop was jointly organized by UNESCO and the South Pacific Commission during February 1990, in Auckland, New Zealand.…

  14. Attitudes on the Population Explosion

    Science.gov (United States)

    Stronck, David R.

    1971-01-01

    Attitudes of biology teachers, prospective teachers, high school students, and adults were compared in regard to the basic principles of Zero Population Growth, the teaching of controversial topics, future state of the world, and Garret Hardin's Graduated Checklist of (28) Heresies." (CP)

  15. Populism and Feminism: Odd Bedfellows.

    Science.gov (United States)

    Kroes, Rob

    2018-01-01

    In this era of populist insurgency breaking the mold of democratic politics, two movements clashed.They represented opposite sides of the political spectrum, one emancipatory, the other exclusionary. One may be identified as feminism, the other as populism. This essay analyzes both concepts and explores their connection.

  16. [Population and employment in China].

    Science.gov (United States)

    Lui, Z

    1980-04-01

    The unequal distribution of farmlands in rural areas and the extremely low productivity in the cities were the fundamental causes of unemployment and population problems in old China. Tremendous progress was made after 1949. The serious economic disturbances caused by Lin-piao and the "Gang of Four" caused great unemployment again. The slow development of China's productivity, poor business management, the involvement of women in social activities, the morality rate decrease, and the population growth rate increase are the main reasons for China's unemployment problem. The fundamental solution is to respect the objective laws of nature and economics and to develop social productivity. In the country we should implement the total development of agricultue, forestry, animal husbandry, and fishery. In towns and cities service occupations and handicraft industries should be developed, education and humanities need to be improved, and transportation, communications, and many other industries are still backward. There is high potential for development and vast opportunities for additional labor. We should constantly cultivate our high quality workforce to meet the demand of modernization. Population control is important because the higher the population growth rate the slower the accumulation of wealth. Instead of being a producer for the society the additional labor can be a burden. The vital factor in achieving the "Four Modernizations" is not the quantity of labor but the increase in productivity.

  17. Populism and Feminism : Odd Bedfellows

    NARCIS (Netherlands)

    Kroes, R.

    In this era of populist insurgency breaking the mold of democratic politics, two movements clashed.They represented opposite sides of the political spectrum, one emancipatory, the other exclusionary. One may be identified as feminism, the other as populism. This essay analyzes both concepts and

  18. Measuring senescence in human populations

    NARCIS (Netherlands)

    Koopman, Jacob Jan Egbert

    2015-01-01

    In this thesis, senescence is measured in human populations according to its definition of an increase in the risks of dysfunction, disease, and death with chronological age. Part I of this thesis investigates how a population’s senescence rate can be measured through the increase in mortality rate

  19. Gender, Education and Population Flows

    DEFF Research Database (Denmark)

    Bennike, Kathrine Bjerg; Faber, Stine Thidemann; Nielsen, Helene Pristed

    During the Danish Presidency for the Nordic Council of Ministers in 2015, attention was drawn towards challenges and best practice examples in relation to gender, education and population flows in peripheral areas throughout the Nordic countries - Norway, Denmark, Sweden, Finland, Iceland...

  20. Reproductive effort in viscous populations

    NARCIS (Netherlands)

    Pen, Ido

    Here I study a kin selection model of reproductive effort, the allocation of resources to fecundity versus survival, in a patch-structured population. Breeding females remain in the same patch for life. Offspring have costly, partial long-distance dispersal and compete for breeding sites, which

  1. Population message from the village.

    Science.gov (United States)

    Hibler, M

    1979-06-01

    According to a number of participants at the population conference in Ontario, sponsored by the School of Journalism of the Univesity of Western Ontario and the Canadian International Development Agency, the villages, in developing countries, have sent a message to population experts, declaring that the most effective way to motivate individuals toward reducing family size is to improve basic educational and health care services. It has been demonstrated that improvements in these areas, by providing women with educational opportunities and by reducing infant mortality, have a direct impact on fertility. Efforts should be directed toward discovering similar direct correlates. The message dismissed as irrelevant the battle raging between those who advocate that population growth must be halted before poverty can be eliminated, between the developmentalists, who believe that fundamental changes in economic and political conditions will automatically solve the population problem, and between those who declare that family planning and development must be dealt with simultaneously for either to be effective. Despite evidence demonstrating the effectiveness of the 'direct correlate' approach, most developing countries continue to accord top priority to family planning programs and neglect educational and health care services.

  2. Population entropies estimates of proteins

    Science.gov (United States)

    Low, Wai Yee

    2017-05-01

    The Shannon entropy equation provides a way to estimate variability of amino acids sequences in a multiple sequence alignment of proteins. Knowledge of protein variability is useful in many areas such as vaccine design, identification of antibody binding sites, and exploration of protein 3D structural properties. In cases where the population entropies of a protein are of interest but only a small sample size can be obtained, a method based on linear regression and random subsampling can be used to estimate the population entropy. This method is useful for comparisons of entropies where the actual sequence counts differ and thus, correction for alignment size bias is needed. In the current work, an R based package named EntropyCorrect that enables estimation of population entropy is presented and an empirical study on how well this new algorithm performs on simulated dataset of various combinations of population and sample sizes is discussed. The package is available at https://github.com/lloydlow/EntropyCorrect. This article, which was originally published online on 12 May 2017, contained an error in Eq. (1), where the summation sign was missing. The corrected equation appears in the Corrigendum attached to the pdf.

  3. Whither the global population problem.

    Science.gov (United States)

    Greep, R O

    1998-02-15

    Growth of the human population has been underway for thousands of years and was never a problem until recently. It is now expanding exponentially, and today global population stands at nearly 6 billion with 97 million being added each year. Currently, overpopulation has led to serious social and environmental problems such as poverty, overcrowded slums, crime, terrorism, pollution of air and water, and depletion of the protective ozone layer. Warnings were sounded, but few listened. The enthusiasm once generated for solving the problem of too many people was short-lived. The press with puzzling abrogation of its responsibility to the public managed to allay all fears of population overgrowth. Two U.S. presidents welcomed such growth as a stimulus to economic development. Although modern contraceptives are safe, effective, and widely available, more are badly needed, but none are in the pipeline. Research is being hampered by hostile attitudes and by the high cost in time and money of bringing a new contraceptive to an uncertain market with the added threat of litigation. At the present rate of growth, the population will double in the next century. This is believed to be beyond the carrying capacity of our planet. Corrective measures by man or nature need to be undertaken.

  4. Disability in Singapore's Elderly Population.

    Science.gov (United States)

    Mahesh, Mithila; Abdin, Edimansyah; Vaingankar, Janhavi Ajit; Picco, Louisa; Jeyagurunathan, Anita; Shafie, Saleha Binte; Pang, Shirlene; Sagayadevan, Vathsala; Seow, Esmond; Chong, Siow Ann; Subramaniam, Mythily

    2016-07-01

    Disability increases an individual's dependence and negatively impacts their physical, mental, and social functioning. The current study aims to establish the prevalence and risk factors of disability in Singapore's population. Data was extracted from the Well-being of the Singapore Elderly (WiSE) study. This cross-sectional study recruited participants aged 60 years and above (n = 2421) who were representative of Singapore's multiethnic population. We used the World Health Organization Disability Assessment Schedule (WHODAS) 2.0 to assess the severity of disability in our sample while establishing its associations and correlations with cognitive levels, sociodemographic variables, and chronic illness. Cognitive deficits, old age, female gender, Malay and Indian ethnicity, lack of education, retired or homemaker status, presence of chronic illness (specifically stroke, heart problems, depression, and dementia) were found to be significantly associated with disability in Singapore's elderly population. As hypothesised, participants with deficits in cognition were more likely to indicate higher WHODAS scores. The findings highlighted specific factors associated with disability in this multiethnic population. The identification of these factors would lead the way to the development of appropriate interventions.

  5. Population and the Colombian economy.

    Science.gov (United States)

    Sanders, T G

    1983-01-01

    Colombia is the only one of the 6 most populous Latin American countries that is currently free of major economic crisis requiring an agreement with the International Monetary Fund. The difference in the economic performances of these countries is relative, since the rate of growth in the Colombian economy was only 1.5% in 1982. Yet, Colombia seems to have weathered the international recession better than most. The crisis atmosphere in the rest of Latin America, triggered by overall economic decline, high rates of inflation, and an indebtedness that soaks up much of export earnings to service it, is lacking in Colombia or present in lesser degree. If Colombia can strengthen its political performance and tighten national unity, it could move through the 1980s with considerable confidence and success in economic development. Colombia differs little from other major Latin American countries with regard to traditionalism and modernization. Most Colombians are secularized. Colombia is far ahead of most comparable Latin American countries in fertility control. The lower rate of population increase defines the extent to which the economy must provide education, health, food, and jobs. 2 other factors are essential for understanding the current situation in Colombia and its prospects for the 1980s. Government policy in the 1970s opted for an austerity program while the other countries were growing rapidly, in large part through borrowed resources. A 2nd factor is the prospect of attaining autonomy in energy production. These special characteristics--population, public policy, and energy--are discussed. Since the mid 1960s Colombia has functioned with 3 family planning programs. Their existence makes contraception easily available to the population generally. In 1960 Colombia had a higher total fertility rate (TFR) 7.0, than either Venezuela (6.6) or Brazil (5.3), but by 1976 its TFR was down to 4.1, while Venezuela's (4.8) and Brazil's (4.3) were now higher. On balance

  6. [Comments on population and ecology].

    Science.gov (United States)

    Negrette, J C

    1990-12-01

    Concern about the condition of the environment and about rapid population growth has a long history. The breadth and magnitude of present day concern may perhaps represent a new development even though the topics themselves are not new. There is almost no country or society that has not manifested disquiet about 1 or the other. Ecology in the strict sense is defined as the relationship between organisms and their environment. In recent decades ecology has come to understood as the manner of avoiding or slowing environmental deterioration or even as the correct and prudent administration of natural resources. The boundaries of the discipline have expanded until today it is concerned with various spheres of the natural and social sciences. The transformations wrought by human beings have been dramatic, both because the use of tools had increased the power of human modification of the environment and because the human population is large and spread over the whole world. Human beings have been responsible for some ecologic disasters, some unintentional like the Exxon Valdez and Chernobyl accidents and others the perhaps unforseen results of deliberate actions, as the contamination of the atmosphere with gas emissions. Environmental deterioration can result from numerous causes, as with the "greenhouse effect" caused by a range of factors including classical contamination and deforestation. Deforestation in developing countries is a response to the combination of poverty and rapid population growth, and is 1 evidence of the close and direct link between population growth and the condition of the environment. The optimism felt during the 1970s about the prospects of bringing world population growth under control has given way to a more realistic and sobering assessment. Many factors including widespread economic difficulties have impeded the progress of family planning programs. It is urgent that efforts to curb rapid population increase be intensified. 1 important means

  7. Population momentum: Implications for wildlife management

    Science.gov (United States)

    Koons, D.N.; Rockwell, R.F.; Grand, J.B.

    2006-01-01

    Maintenance of sustainable wildlife populations is one of the primary purposes of wildlife management. Thus, it is important to monitor and manage population growth over time. Sensitivity analysis of the long-term (i.e., asymptotic) population growth rate to changes in the vital rates is commonly used in management to identify the vital rates that contribute most to population growth. Yet, dynamics associated with the long-term population growth rate only pertain to the special case when there is a stable age (or stage) distribution of individuals in the population. Frequently, this assumption is necessary because age structure is rarely estimated. However, management actions can greatly affect the age distribution of a population. For initially growing and declining populations, we instituted hypothetical management targeted at halting the growth or decline of the population, and measured the effects of a changing age structure on the population dynamics. When we changed vital rates, the age structure became unstable and population momentum caused populations to grow differently than that predicted by the long-term population growth rate. Interestingly, changes in fertility actually reversed the direction of short-term population growth, leading to long-term population sizes that were actually smaller or larger than that when fertility was changed. Population momentum can significantly affect population dynamics and will be an important factor in the use of population models for management.

  8. [Population: evolution of Rwandan attitudes or the adaptation of the Rwanda population to population growth].

    Science.gov (United States)

    Ngendakumana, M

    1988-04-01

    A consequence of the increasing pressure on Rwanda's ecosystem resulting from population growth has been that demographic factors have played a significant role in modifying attitudes and beliefs of the population. The history of Rwanda demonstrates a constant struggle for survival in the face of increasing population pressure. Migration, colonization of new agricultural lands, adoption of new crops and new forms of animal husbandry have been responses to population pressures. Recent unprecedented population growth has exceeded the capacity of older systems of cultivation and combinations of agricultural and animal husbandry to support the population. Smaller animals have largely replaced the cattle that once roamed freely in extensive pastures, and new techniques of stabling animals, use of organic or chemical fertilizers, and new tools adapted to the shrinking size of farm plots have represented responses to the new demographic realities. The concept of the family is likewise undergoing modification in the face of population growth and modernization. Children, who once were valued as a source of labor and constrained to conform to the wishes of the parents in return for the eventual inheritance of the goods and livelihood, now increasingly look beyond the household for education and employment. Family land holdings have become too small to support all the members with a claim on them. The greater distances between family members inevitably mean that relations between them lose closeness. The choice of a marriage partner is increasingly assumed by the young people themselves and not by their families. Old traditions of food sharing and hospitality have been curtailed because of the increasing scarcity of food. Despite the changes engendered by increasing population pressure, pronatalist sentiments are still widespread. But the desire to assure the future of each child rather than to await his services, a new conception of women less dependent on their reproductive

  9. Pharmacogenetics in the Brazilian population

    Directory of Open Access Journals (Sweden)

    Guilherme eSuarez-Kurtz

    2010-10-01

    Full Text Available Brazil is the 5th largest country in the world and its present population, in excess of 190 million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians, most individuals - irrespective of self-identification as White, Brown or Black, the major categories of the Brazilian Census race/color system - having significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g. CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV-protease inhibitors and nonsteroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen (www.refargen.org.br, a nationwide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact.

  10. Philippine president announces population policy.

    Science.gov (United States)

    1970-02-01

    President Ferdinand Marcos of the Philippines has announced a national policy for family planning, following his recent reelection for a second term of office. Under the policy adopted by the President, the Philippine Government is committed to undertake and encourage programs to provide information and advice for couples wishing to space or limit their child-bearing activities. The Presidential Commission on Population, in a report based on recommendations drawn up after more than 20 meetings by the 22 members, and states that the unfettered population growth will gravely hamper efforts to improve living standards for Filipinos and will block the attainment of national development goals. However, the Commission emphasized that the program will be educational and persuasive, not coercive. Family planning services have been growing rapidly in the Philippines over the past few years as a result of the initiative of several pioneer organizations assisted by the IPPF. President Marcos' government signed the United Nations Declaration on Population in 1967 and in January 1969 he established The Commission on Population. The Philippine press has consistently backed the campaign for widespread availability of family planning services. The Western Pacific Region of the World Health Organization, under it's Director, Dr. Francisco Dy, which has its headquarters in Manila, has its headquarters in Manila, has fostered a regional interest through its technical discussions and the training of field personnel. Depthnews recently reported that the latest Philippine demographic survey asserts that Filipina women are bearing children so fast that the country will hold on to the undisputed title of possessing the highest birth rate in Asia. The growth rate is 3.5%, and the average completed size of a Filipino family is 6.8 children. This swift rate of growth will boost the 1969 population of 37.1 million to 38.4 at the end of this decade. It is noted that unless curbed, it will

  11. Pharmacogenetics in the brazilian population.

    Science.gov (United States)

    Suarez-Kurtz, Guilherme

    2010-01-01

    Brazil is the fifth largest country in the world and its present population, in excess of 190;million, is highly heterogeneous, as a result of centuries of admixture between Amerindians, Europeans, and Sub-Saharan Africans. The estimated individual proportions of biogeographical ancestry vary widely and continuously among Brazilians: most individuals, irrespective of self-identification as White, Brown or Black - the major categories of the Brazilian Census "race/color" system - have significant degrees of European and African ancestry, while a sizeable number display also Amerindian ancestry. These features have important pharmacogenetic (PGx) implications: first, extrapolation of PGx data from relatively well-defined ethnic groups is clearly not applicable to the majority of Brazilians; second, the frequency distribution of polymorphisms in pharmacogenes (e.g., CYP3A5, CYP2C9, GSTM1, ABCB1, GSTM3, VKORC, etc) varies continuously among Brazilians and is not captured by race/color self-identification; third, the intrinsic heterogeneity of the Brazilian population must be acknowledged in the design and interpretation of PGx studies in order to avoid spurious conclusions based on improper matching of study cohorts. The peculiarities of PGx in Brazilians are illustrated with data for different therapeutic groups, such as anticoagulants, HIV protease inhibitors and non-steroidal antinflammatory drugs, and the challenges and advantages created by population admixture for the study and implementation of PGx are discussed. PGx data for Amerindian groups and Brazilian-born, first-generation Japanese are presented to illustrate the rich diversity of the Brazilian population. Finally, I introduce the reader to the Brazilian Pharmacogenetic Network or Refargen, a nation-wide consortium of research groups, with the mission to provide leadership in PGx research and education in Brazil, with a population health impact.

  12. "India Population Projects" in Karnataka.

    Science.gov (United States)

    Reddy, P H; Badari, V S

    1991-12-01

    An overview, objectives, implementation, and research and evaluation studies of 2 India Population Projects in Karnataka are presented. The India Population Project I (IPP-I) was conducted in Karnataka and Uttar Pradesh. India Population Project III (IPP-III) took place between 1984-92 in 6 districts of Karnataka: Belgaum, Bijapur, Dharwad, Bidar, Gulbarga, and Raichur, and 4 districts in Kerala. The 6 districts in Karnataka accounted for 36% (13.2 million) of the total national population. The project cost was Rs. 713.1 million which was shared by the World Bank, and the Indian national and regional government. Due to poor past performance, these projects were undertaken to improve health and family welfare status. Specific project objectives are outlined. IPP-I included an urban component, and optimal Government of India program, and an intensive rural initiative. The urban program aimed to improved pre- and postnatal services and facilities, and the family planning (FP) in Bangalore city. The rural program was primarily to provide auxiliary nurse-midwives and hospitals and clinics, and also supplemental feeding program for pregnant and nursing mothers and children up to 2 years. The government program provided FP staff and facilities. IPP-I had 3 units to oversee building construction, to recruit staff and provide supplies and equipment, and to establish a Population Center. IPP-III was concerned with service delivery; information, education, and communication efforts (IEC) and population education; research and evaluation; and project management. Both projects contributed significantly to improving the infrastructure. A brief account of the types and kinds of studies undertaken is given. Studies were grouped into longitudinal studies of fertility, mortality, and FP; management information and evaluation systems for health and family welfare programs; experimental strategies; and other studies. Research and evaluation studies in IPP-III encompassed studies in

  13. GPU accelerated population annealing algorithm

    Science.gov (United States)

    Barash, Lev Yu.; Weigel, Martin; Borovský, Michal; Janke, Wolfhard; Shchur, Lev N.

    2017-11-01

    Population annealing is a promising recent approach for Monte Carlo simulations in statistical physics, in particular for the simulation of systems with complex free-energy landscapes. It is a hybrid method, combining importance sampling through Markov chains with elements of sequential Monte Carlo in the form of population control. While it appears to provide algorithmic capabilities for the simulation of such systems that are roughly comparable to those of more established approaches such as parallel tempering, it is intrinsically much more suitable for massively parallel computing. Here, we tap into this structural advantage and present a highly optimized implementation of the population annealing algorithm on GPUs that promises speed-ups of several orders of magnitude as compared to a serial implementation on CPUs. While the sample code is for simulations of the 2D ferromagnetic Ising model, it should be easily adapted for simulations of other spin models, including disordered systems. Our code includes implementations of some advanced algorithmic features that have only recently been suggested, namely the automatic adaptation of temperature steps and a multi-histogram analysis of the data at different temperatures. Program Files doi:http://dx.doi.org/10.17632/sgzt4b7b3m.1 Licensing provisions: Creative Commons Attribution license (CC BY 4.0) Programming language: C, CUDA External routines/libraries: NVIDIA CUDA Toolkit 6.5 or newer Nature of problem: The program calculates the internal energy, specific heat, several magnetization moments, entropy and free energy of the 2D Ising model on square lattices of edge length L with periodic boundary conditions as a function of inverse temperature β. Solution method: The code uses population annealing, a hybrid method combining Markov chain updates with population control. The code is implemented for NVIDIA GPUs using the CUDA language and employs advanced techniques such as multi-spin coding, adaptive temperature

  14. Stochastic problems in population genetics

    CERN Document Server

    Maruyama, Takeo

    1977-01-01

    These are" notes based on courses in Theoretical Population Genetics given at the University of Texas at Houston during the winter quarter, 1974, and at the University of Wisconsin during the fall semester, 1976. These notes explore problems of population genetics and evolution involving stochastic processes. Biological models and various mathematical techniques are discussed. Special emphasis is given to the diffusion method and an attempt is made to emphasize the underlying unity of various problems based on the Kolmogorov backward equation. A particular effort was made to make the subject accessible to biology students who are not familiar with stochastic processes. The references are not exhaustive but were chosen to provide a starting point for the reader interested in pursuing the subject further. Acknowledgement I would like to use this opportunity to express my thanks to Drs. J. F. Crow, M. Nei and W. J. Schull for their hospitality during my stays at their universities. I am indebted to Dr. M. Kimura...

  15. Environmental impact of population growth

    Science.gov (United States)

    Naylor, Rosamond; Matson, Pamela

    Earth's population currently numbers 5.4 billion; even given optimistic assumptions for reduction in growth rates, the number will double by the middle of the next century with most of the increase in the developing countries. Rapid population growth in the developing world raises the fundamental dilemma of how to alleviate chronic hunger and poverty in the short run while preserving the atmosphere and ecosystem services required for long-term human and biospheric sustenance. This dilemma, and the compromises required to solve it, were discussed by twenty-five researchers from five countries at the Aspen Global Change Institute 1992 Summer Science Session III, Food, Conservation, and Global Environmental Change: Is Compromise Possible?, held from August 16 to 28, in Aspen, Colo.

  16. Statistical thermodynamics of clustered populations.

    Science.gov (United States)

    Matsoukas, Themis

    2014-08-01

    We present a thermodynamic theory for a generic population of M individuals distributed into N groups (clusters). We construct the ensemble of all distributions with fixed M and N, introduce a selection functional that embodies the physics that governs the population, and obtain the distribution that emerges in the scaling limit as the most probable among all distributions consistent with the given physics. We develop the thermodynamics of the ensemble and establish a rigorous mapping to regular thermodynamics. We treat the emergence of a so-called giant component as a formal phase transition and show that the criteria for its emergence are entirely analogous to the equilibrium conditions in molecular systems. We demonstrate the theory by an analytic model and confirm the predictions by Monte Carlo simulation.

  17. Modern pesticides and bobwhite populations

    Science.gov (United States)

    Stromborg, K.L.; Schitoskey, Frank=; Schitoskey, Elizabeth C.; Talent, Larry G.

    1982-01-01

    Bobwhite (Colinus virginianus) are frequently used as test animals for wildlife tests of pesticides. The organophosphate and carbamate pesticides that have replaced the organochlorines have many desirable properties, but they span a wide range of acute toxicities and some of them affe,ct survival, reproduction, food consumption, behavior, and nervous system enzymes in laboratory tests. Applying these laboratory findings to the field requires assumptions about the severity of exposure in the field. Direct field measurements show that birds may be exposed to significant amounts of these pesticides or even more toxic degradation products under some conditions. Adverse population effects may also result from depression of insect populations during the seasons when bobwhites rely on insects for food.

  18. Dynamical systems in population biology

    CERN Document Server

    Zhao, Xiao-Qiang

    2017-01-01

    This research monograph provides an introduction to the theory of nonautonomous semiflows with applications to population dynamics. It develops dynamical system approaches to various evolutionary equations such as difference, ordinary, functional, and partial differential equations, and pays more attention to periodic and almost periodic phenomena. The presentation includes persistence theory, monotone dynamics, periodic and almost periodic semiflows, basic reproduction ratios, traveling waves, and global analysis of prototypical population models in ecology and epidemiology. Research mathematicians working with nonlinear dynamics, particularly those interested in applications to biology, will find this book useful. It may also be used as a textbook or as supplementary reading for a graduate special topics course on the theory and applications of dynamical systems. Dr. Xiao-Qiang Zhao is a University Research Professor at Memorial University of Newfoundland, Canada. His main research interests involve applied...

  19. Cancer patterns in Inuit populations

    DEFF Research Database (Denmark)

    Melbye, M.; Friborg, Jeppe Tang

    2008-01-01

    to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet......, and reproductive factors. This Review will briefly summarise the current knowledge on cancer epidemiology in Inuit populations, with emphasis on the characteristic Inuit types of cancer Udgivelsesdato: 2008/9...... a distinct pattern, characterised by a high risk of Epstein-Barr virus-associated carcinomas of the nasopharynx and salivary glands, and a low risk of tumours common in white populations, including cancer of the prostate, testis, and haemopoietic system. Both genetic and environmental factors seem...

  20. Population growth can be checked.

    Science.gov (United States)

    Shukla, J P

    Since independence, India's population size has doubled. The rate of growth was 2.5% during 1971-81, an increase from the rate of 2.15% observed during the 1951-61 period. The increase indicated that efforts to decrease population growth have not succeeded. The implications with respect to food, housing, clothing, education, and health facilities, which are fundamental to improving the physical quality of life, are severe. This demographic trend is a serious impediment to progress. The population growth is due to a constant birthrate and a sharp decline in mortality. Reducing the birthrate is necessary to reduce the rate of growth. An attitudinal change adopting the norm of family limitation should be encouraged through propaganda, socioeconomic programs, and religious and cultural organizations. Other measures to bring about a decline in the birthrate include: increasing the marriage age, and expanding educational and employment opportunities for women and girls. These measures will require substantial effort and time. Incentives may show more immediate effects. Monetary incentives are not desired because of the possibility of misuse. However the government could assume responsibility for the education and guarantee employment of children of couples who have only one child, and provide free education to children of couples with only 2 children. These incentives are not likely to be misused, can be available to all segments of the population, and involve no immediate large financial burden on the government. In addition, scholarships to the Harijan students should be limited to 2 per family. If these measures are accepted, they could quickly reduce the birth rate.

  1. World Population Day special symposium.

    Science.gov (United States)

    1998-08-01

    This article describes Japan's celebration of World Population Day, and provides excerpts from speeches at the symposium held on July 8, 1998. The symposium, in Tokyo, was attended by about 300 people. The Chairman of JOICFP gave the opening address. The executive director of UNFPA congratulated Japan for its efforts in the field of population awareness and noted Japan's self-sufficiency despite its importation of 40% of its food and most of its raw materials. A keynote address was delivered by the president of CPE and the former UN Secretary General, who stressed income inequities in the 66% of developing countries within the 185 UN member states. The UN has been promoting sustainable development, but is facing the issue of limited arable land and population growth. The Tutsi and Hutus are fighting due to population based issues. The emphasis should be on women's reproductive rights and protection of women's human rights. 1998 is the 50th year of human rights; progress has been made. The UNFPA Goodwill Ambassador spoke about the disparity between the rich and poor in the Philippines. A small donation reaps incredible progress. Manila has high levels of adolescent childbearing. Men appear to be unaware of the disadvantages of childbearing too early. Rural areas are dominated by strict Roman Catholic beliefs. Manila has commercial sex workers who provide services to Japanese men. The 1998 Kato Award was given to women who raised awareness about coercion in the sex trade and female genital mutilation. The economic situation in Japan creates even greater need to promote family planning and reproductive health.

  2. New population law for Mexico.

    Science.gov (United States)

    1974-02-01

    A bill of additions and reforms to Mexico's General Law on Population, which established a legal framework for planned parenthood programs as part of a general development policy, set guidelines for the protection of human rights in public and private programs, and dealt with migration, immigration, emigration, and repatriation, was announced initially by Mexican President Luis Echeverria as one step toward reducing Mexico's 3.5% annual rate of growth. The legislation became law on January 7, 1974.

  3. a population-based study

    OpenAIRE

    Gholami, Mahdia; Pakdaman, Afsaneh; Montazeri, Ali; Jafari, Ahmad; Virtanen, Jorma I.

    2014-01-01

    Background Oral health promotion can be achieved through education using various approaches including mass media health education campaigns. Mass media campaigns might increase oral health knowledge and perhaps could lead to desired behaviour changes and prevention of oral diseases. The aim of this study was to assess the effect of a national television campaign on knowledge of periodontal health among Iranian adults. Methods We conducted a population-based survey among adults aged 18–50 usin...

  4. Population growth and economic development.

    Science.gov (United States)

    Corbridge, S

    1989-01-01

    The Malthusian and neo-Malthusian approaches to the role of population growth in economic development and resource depletion are briefly outlined. Three arguments are then presented that emphasize demographic determinism, empirical evidence, and cause and effect. The author concludes that non-coercive family planning programs may have a role to play in countries that are unable to reduce inequalities, particularly for the poor and for women.

  5. Endogenous Population and Environmental Quality

    OpenAIRE

    Phu NGUYEN VAN

    2002-01-01

    This paper provides with empirical and theoretical studies of the relationship between population, economic growth and environmental quality. Using a simple endogenous growth model we obtain results close to empirical findings. We show existence of a sustainable balanced growth path (BGP) equilibrium in which perpetual economic growth goes in parallel with environmental quality preservation. At the BGP equilibrium, when all exogenous factors are controlled, a negative relationship between fer...

  6. From Population to Organization Thinking

    OpenAIRE

    Lane, David; Maxfield, Robert; Read, Dwight W; van der Leeuw, Sander E

    2009-01-01

    This chapter begins by reviewing the Darwinian account of biological innovation, which is based on what Ernst Mayr calls “population thinking” and posits two kinds of key mechanisms underlying the innovation process, variation and selection. The chapter then argues that the increasingly popular tendency to adapt this account to provide the foundations for a theory of human sociocultural innovation is ill-advised. Human sociocultural organizations are self-reflexive and self-modifying, through...

  7. Population mobility in Peninsular Malaysia.

    Science.gov (United States)

    Jones, G W; Sidh, M S

    1979-12-01

    1970 census materials were used to analyze migration patterns in Peninsular Malaysia. Inter-state migration patterns were analyzed by comparing birth place and current place of residence data, and inter-district and intra-district migration patterns were assessed using information on previous and current place of residence. The proportion of inter-state migrants in the total population increased from 4.7%-10.9% from 1947-1970. 53% of the inter-state migrants were Malays, 33% were Chinese, and 13% were Indian. The states of Selangor and Pahang had the highest net migration gains and Perak had the highest number of out-migrants. Selangor attracted migrants because it was a major industrial, administrative and educational center. Migrants were attracted to Pahang because of recent efforts by the government to promote agricultural development in the state. Areas which showed a net migration loss were experiencing slow economic growth. 48.4% of the inter-state migrants migrated to either rural or suburban areas, 26% moved to cities with populations of 75,000 or more, and 26% moved to towns with populations of 1000-10,000. 48.6% of the inter-state migrants were females. When all types of internal migration were taken into account it was estimated that approximately 30% of the population had moved at some point in their life time. During the early 1900s, Peninsular Malaysia received many immigrants from China, India, and other countries, and the Chinese became the dominant group in many urban areas and in many economic sectors. In 1950 the government, fearing that the Malays would become a minority group in their own country, halted international immigration. The recent increase in internal migration has contributed toward equalizing the influence and power of the Chinese and the Malays in urban areas and in various economic sectors.

  8. Incorporating territory compression into population models

    NARCIS (Netherlands)

    Ridley, J; Komdeur, J; Sutherland, WJ; Sutherland, William J.

    The ideal despotic distribution, whereby the lifetime reproductive success a territory's owner achieves is unaffected by population density, is a mainstay of behaviour-based population models. We show that the population dynamics of an island population of Seychelles warblers (Acrocephalus

  9. 45 CFR 1356.81 - Reporting population.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or provided...

  10. NIDI scenario. Strong population decline in China

    NARCIS (Netherlands)

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario

  11. Developing Education Programs or Population Awareness.

    Science.gov (United States)

    Viederman, Stephen

    Speakers on population matters often refer to the population explosion with an air of crisis. It is questionable that images of doomsday are defensible for us in our role as educators. The goals of population education are to develop an understanding of the impacts of population characteristics on national development, as well as their impact on…

  12. Role of women in population.

    Science.gov (United States)

    Srivasdava, T N

    Population control through voluntary adoption of family planning is emphasized in India's family planning policy. The 1981 census figures have not shown an arresting rate of population growth. The social and attitudinal barriers to promoting the concept of the small family are great where men and women are not exposed to new ideas. The target groups for family planning include the 75% of the population residing in rural areas. The literacy rate for women in rural areas in 1971 was 18.69. Motivation is difficult unless supported by systematic education. Women play an important role in the determination of family size. Participation in social and economic activities may help to promote small family size by meeting the necessary conditions of emotional and social fulfillment of women outside the family context. Adquate education for women in rural as well as urban areas can elucidate alternatives to childbearing and enable women to appreciate the need for and use of contraception. Employment opportunities enhance women's familial decision making power through the acquisition of an alternative social and economic role, which may help them to adopt birth control practices, space their children, and limit family size. Motivational schemes may change the attitudes of a small number of families, however, greater gains could be achieved through an investment in women's education and employment.

  13. Population issues in clinical trials.

    Science.gov (United States)

    Mosenifar, Zab

    2007-05-01

    Inclusion of underrepresented groups in clinical trials is important for several reasons. Age, sex, race, genetic factors, concomitant use of other medications, and comorbid conditions all may play pivotal roles in response to a drug or intervention. Despite the legislation for broader inclusion of underrepresented groups in clinical trials (via the National Institutes of Health [NIH] Revitalization Act of 1993), underrepresentation of particular populations, particularly minorities, continues to be a problem. Studies of predictors of clinical trial enrollment suggest that most people participate in clinical research to find relief from a disease, not for financial remuneration. Yet, men and whites are more likely to enroll in studies and some data indicate that certain patient populations are preferentially (albeit sometimes inadvertently) chosen for study enrollment. This tendency toward inclusion stems from human nature-the natural tendency for an investigator to relate to a particular investigative topic due to a special connection based on a cultural, socioeconomic, age, ethnicity, or gender level. This article reviews the most common population issues for clinical studies: age, gender, race, socioeconomic status, comorbidities, and disease severity, with examples of each from published studies. Recommendations are also offered to overcome these barriers.

  14. Population growth and global warming

    Science.gov (United States)

    Short, R.V.

    2009-01-01

    When I was born in 1930, the human population of the world was a mere 2 billion. Today, it has already reached 6.8 billion, and is projected to reach 9.1 billion by 2050. That is unsustainable. It is slowly beginning to dawn on us that Global Warming is the result of increasing human CO2 emissions, and the more people there are in the world, the worse it will become. Ultimately, it is the sky that will prove to be the limit to our numbers. The developed countries of the world are the most affluent, and also the most effluent, so we must lead by example and contain our own population growth and per capita emissions. We also have a big debt to repay to former colonial territories in Africa, Asia and South America, who desperately need our help to contain their excessive rates of population growth. Belgian and Dutch obstetricians and gynaecologists can play a critical role in this endeavour. After all, we already have a pill that will stop global warming – the oral contraceptive pill. PMID:25478068

  15. FSPS: Flexible Stellar Population Synthesis

    Science.gov (United States)

    Conroy, Charlie; Gunn, James E.

    2010-10-01

    FSPS is a flexible SPS package that allows the user to compute simple stellar populations (SSPs) for a range of IMFs and metallicities, and for a variety of assumptions regarding the morphology of the horizontal branch, the blue straggler population, the post-AGB phase, and the location in the HR diagram of the TP-AGB phase. From these SSPs the user may then generate composite stellar populations (CSPs) for a variety of star formation histories (SFHs) and dust attenuation prescriptions. Outputs include the "observed" spectra and magnitudes of the SSPs and CSPs at arbitrary redshift. In addition to these fortran routines, several IDL routines are provided that allow easy manipulation of the output. FSPS was designed with the intention that the user would make full use of the provided fortran routines. However, the full FSPS package is quite large, and requires some time for the user to become familiar with all of the options and syntax. Some users may only need SSPs for a range of metallicities and IMFs. For such users, standard SSP sets for several IMFs, evolutionary tracks, and spectral libraries are available here.

  16. Population growth and global warming.

    Science.gov (United States)

    Short, R V

    2009-01-01

    When I was born in 1930, the human population of the world was a mere 2 billion. Today, it has already reached 6.8 billion, and is projected to reach 9.1 billion by 2050. That is unsustainable. It is slowly beginning to dawn on us that Global Warming is the result of increasing human CO2 emissions, and the more people there are in the world, the worse it will become. Ultimately, it is the sky that will prove to be the limit to our numbers. The developed countries of the world are the most affluent, and also the most effluent, so we must lead by example and contain our own population growth and per capita emissions. We also have a big debt to repay to former colonial territories in Africa, Asia and South America, who desperately need our help to contain their excessive rates of population growth. Belgian and Dutch obstetricians and gynaecologists can play a critical role in this endeavour. After all, we already have a pill that will stop global warming - the oral contraceptive pill.

  17. Population change, resources and environment.

    Science.gov (United States)

    1982-06-01

    Environmental pollution is a problem of crisis proportions in today's world, presently more visible in technologically advanced than in the developing countries. Progress and affluence in the technologically developed countries has been achieved at the expense of depletion of natural resources and deterioration of the environment at the global level. Each of the 3 important factors responsible for environmental pollution--population growth, increase in affluence, and industrialization--are reviewed. There are direct and indirect effects of population growth on the environment. Other things being equal, the greater the population, the more significant are the changes brought about in the environment. More people increases demands on food, energy, housing, clothing, and transportation, all of which lead to environmental pollution. Poor quality or insufficiency of food supply, sanitation, water supply, housing, employment, and health and other services are common problems in countries with high rates of population increase. Problems of domestic sewage and solid waste disposal are directly related to the number of people. Economic growth means more consumption of resources. The effect of affluence can possibly be better understood in the context of the problem of food. With the improved economic status of the peole in many countries, the composition of their diet has been changing. Examining the grain requirements in different countries is a way to understand the effect of increased affluence on the demand for food. During 1969-70 the high income countries with 30% of the world population accounting for 51% of the total consumption of cereals. The higher rate of consumption of cereals in the developed countries is due to indirect utilization. Cereals which can be directly consumed by humans are fed to cattle. The per capita amount of direct and indirect grain consumption continues to increase as per capita income climbs. Developing countries, in their anxiety to

  18. Checking population pressure in India.

    Science.gov (United States)

    Mittal, S P

    1983-01-26

    In India the need for controlling the population explosion is greater than ever before. This is because the 1981 census shows that the rate of population growth is too fast to be matched by the rate of economic development, meaning that whatever gains are made from development projects will be neutralized by the increased demand from the growing population. Against this background, increased awareness has arisen of the need to spare no efforts to contain population growth. In 1961 the target set was to reduce the birthrate to 25/1000 by 1973, but the birthrate was reduced only to 33/1000. The revised target is to reduce the birthrate to 21/1000 by the year 2000. To achieve the target it is necessary to cover at least 60% of the eligibile couples with contraceptive services by 2000 compared to the present level of 20% coverage of eligible couples. The question that arises is whether the present policies and programs are adequate for achieving the target. The people must be motivated, and the environment must be made conducive to greater acceptance of family planning. This cannot be accomplished by the government alone. If community leaders are involved, there is a greater chance of family planning acceptance. It was this realization that was responsible for the formation of the Indian Association of Parliamentarians on Population and Development with a view toward supplementing the efforts at the official level for the acceptance of the concept of the small family and providing the necessary services at the doorsteps of the people. The Association has been successful in creating an environment of political consensus in favor of family planning. Apart from education and motivational campaigns, there are incentives and disincentives. Incentives include monetary compensation to acceptors and motivators. Some opposition exists in relation to disincentives. The feeling exists that the line between compulsion and disincentives is very thin. The following are included

  19. How fast is population ageing in China?

    OpenAIRE

    Yinhua mai; Xiujian Peng; Wei Chen

    2009-01-01

    Using adjusted 2000 population census data, this paper conducts China's population projections to 2050. Three fertility and four mortality scenarios yield 12 sets of results. Despite the below-replacement fertility, China's population will continue growing for many years. However, there are substantial differences among the twelve scenarios. The maximum population could range from less than 1.4 billion to more than 1.6 billion. One of the notable trends is the rapid population ageing. By the ...

  20. Microbial populations in contaminant plumes

    Science.gov (United States)

    Haack, Sheridan K.; Bekins, Barbara A.

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation. La biodégradation efficace des polluants souterrains requiert deux éléments: des populations microbiennes possédant les aptitudes nécessaires à la dégradation, et des conditions géochimiques et hydrologiques souterraines favorables. Des contraintes pratiques sur la conception et l'interprétation des expériences à la fois en microbiologie et en hydrogéologie ont conduit à une connaissance limitée des interactions entre les

  1. Golija: Population development and perspectives

    Directory of Open Access Journals (Sweden)

    Vojković Gordana

    2006-01-01

    Full Text Available The basic research idea was to determine the state and problems in population development of an isolated mountainous region, which has been marked as a potentially developmental and attractive region in the Regional Plan of Serbia, having in mind that it is rich in valuable natural resources. Research was focused just on the protected region of the "Golija" Nature Park, however, wherever it was necessary for better understanding of demographic trends, the wider functional-gravitational region was analyzed, which belongs to the districts of Ivanjica, Kraljevo, Novi Pazar, Raška and Sjenica in the administration sense. It was determined that the following unfavorable (limiting elements of demographic development are characteristic for the region of Golija: constant decrease of population, which is present in practically all settlements, intensive population emigration which has been decreasing in the last ten years or so due to the decrease in the number of potential emigrants; fluctuations in all relevant demographic structures; intensification of the process of demographic ageing which results in continual decrease of natural growth and disruption of all basic functional contingents of population which will certainly negatively affect future reproduction and population replacement. If such a negative state is taken into consideration then the question of demographic and thus developmental perspectives of this mountainous region is justifiably imposed and brought into question. The second part of the paper indicates to the demographic perspectives of the Golija region. According to the first estimation variant, which proceeds from the assumption on the continuation of the basic tendencies in demographic development so far, the number of inhabitants of Golija would be halved by the year 2030. In the second estimation variant, which proceeds from the assumption that in the near future some more serious changes in the functional structure of this

  2. Culture´Contribution to Democracy: Culture, nationalisme and Populism

    DEFF Research Database (Denmark)

    Duelund, Peter

    2018-01-01

    Developments on culture, populism and democracy in Europe. Reasons to populism?   Is populism a new phenomenon? Populism as catch-all label? Common indicators of populism How to deal with populists? Proposal to a comparative COE study on populism......Developments on culture, populism and democracy in Europe. Reasons to populism?   Is populism a new phenomenon? Populism as catch-all label? Common indicators of populism How to deal with populists? Proposal to a comparative COE study on populism...

  3. Population genetics and cryptic species

    International Nuclear Information System (INIS)

    McPheron, Bruce A.

    2000-01-01

    Does the definition of a species matter for pest management purposes? Taxonomists provide us with tools - usually morphological characters - to identify a group of organisms that we call a species. The implication of this identification is that all of the individuals that fit the provided description are members of the species in question. The taxonomists have considered the range of variation among individuals in defining the species, but this variation is often forgotten when we take the concept of species to the level of management. Just as there is morphological variation among individuals, there is also variation in practically any character we might imagine, which has implications for the short and long term success of our management tactics. The rich literature on insecticide resistance should be a constant reminder of the fact that the pressure on pest survival and reproduction applied by our management approaches frequently leads to evolutionary changes within the pest species. The degree of variation within a particular species is a defining characteristic of that species. This level of variability may have very important implications for successful management, so it is very important to measure variation and, whenever possible, the genetic basis of that variation, in a target species. Population genetic approaches can provide evidence of genetic structure (or lack thereof) among populations of a species. These types of data can be used to discuss the movement of pest populations on a local or global scale. In other cases, we may have a complex of species that share some, but not all, characteristics. Species complexes that share morphological characters (i.e., cannot be easily distinguished) but not biological characters are referred to as sibling or cryptic species

  4. Populations of concern: Chapter 9

    Science.gov (United States)

    Gamble, Janet; Balbus, John; Berger, Martha; Bouye, Karen; Campbell, Vince; Chief, Karletta; Conlon, K.; Crimmins, Allison; Flanagan, Barry; Gonzalez-Maddux, C.; Hallisey, E.; Hutchins, S.; Jantarasami, L.; Khoury, S.; Kiefer, M.; Kolling, J.; Lynn, K.; Manangan, A.; McDonald, M.; Morello-Frosch, R.; Hiza, Margaret; Sheffield, P.; Thigpen Tart, K.; Watson, J.; Whyte, K.P.; Wolkin, A.F.

    2016-01-01

    Climate change is already causing, and is expected to continue to cause, a range of health impacts that vary across different population groups in the United States. The vulnerability of any given group is a function of its sensitivity to climate change related health risks, its exposure to those risks, and its capacity for responding to or coping with climate variability and change. Vulnerable groups of people, described here as populations of concern, include those with low income, some communities of color, immigrant groups (including those with limited English proficiency), Indigenous peoples, children and pregnant women, older adults, vulnerable occupational groups, persons with disabilities, and persons with preexisting or chronic medical conditions. Planners and public health officials, politicians and physicians, scientists and social service providers are tasked with understanding and responding to the health impacts of climate change. Collectively, their characterization of vulnerability should consider how populations of concern experience disproportionate, multiple, and complex risks to their health and well-being in response to climate change. Some groups face a number of stressors related to both climate and non-climate factors. For example, people living in impoverished urban or isolated rural areas, floodplains, coastlines, and other at-risk locations are more vulnerable not only to extreme weather and persistent climate change but also to social and economic stressors. Many of these stressors can occur simultaneously or consecutively. Over time, this “accumulation” of multiple, complex stressors is expected to become more evident1 as climate impacts interact with stressors associated with existing mental and physical health conditions and with other socioeconomic and demographic factors.

  5. World population problems: an overview.

    Science.gov (United States)

    Potts, M

    1989-06-01

    Over 50% of the world's population is below the age of marriage, which indicates rapid expansion of the population into the next century. The developing countries produce 85% of the births, 95% of infant deaths, and in some, 99% of maternal deaths. Acquired immunodeficiency syndrome (AIDS) will slow population growth but will not reverse the trend. Family planning programs have worked as evidenced by declining fertility rates. In the US there was a total fertility rate decline of 6 to 3.5 in 58 years. In Sri Lanka the same change took 30 years, in Thailand 15 years and in China 7 years. Family planning programs that are successful provide condoms cheaply, provide community distribution of pills, offer sterilization to male and females, and promote long periods of lactation. Abortion rates are often higher in countries where they are illegal and family planning is usually not offered. Social marketing and voluntary sterilization are the most cost effective birth control methods as proven in less developed countries. Management is the vital factor in more cost effective family planning programs. In sub-Saharan Africa and India there will be a need to subsidize contraceptives well into the next century. If the world is to be serious about family planning, many industrialized countries will have to contribute resources. Private sector involvement needs to be emphasized more in developing countries. Resources are low because of a lack of political will caused by a lack of understanding of the facts of demographic growth. There have been estimates that it will take $7.5 billion to satisfy the developing countries' birth control needs: there is only $1.5 billion being spent now. Many countries are not providing family planning quickly enough and may be forced to give up the freedom to choose family size. The choice of policy makers now is to increase the resources for contraceptive research, or to settle with abortion and sterilization as backup to inadequate methods.

  6. Population Genomics of Paramecium Species.

    Science.gov (United States)

    Johri, Parul; Krenek, Sascha; Marinov, Georgi K; Doak, Thomas G; Berendonk, Thomas U; Lynch, Michael

    2017-05-01

    Population-genomic analyses are essential to understanding factors shaping genomic variation and lineage-specific sequence constraints. The dearth of such analyses for unicellular eukaryotes prompted us to assess genomic variation in Paramecium, one of the most well-studied ciliate genera. The Paramecium aurelia complex consists of ∼15 morphologically indistinguishable species that diverged subsequent to two rounds of whole-genome duplications (WGDs, as long as 320 MYA) and possess extremely streamlined genomes. We examine patterns of both nuclear and mitochondrial polymorphism, by sequencing whole genomes of 10-13 worldwide isolates of each of three species belonging to the P. aurelia complex: P. tetraurelia, P. biaurelia, P. sexaurelia, as well as two outgroup species that do not share the WGDs: P. caudatum and P. multimicronucleatum. An apparent absence of global geographic population structure suggests continuous or recent dispersal of Paramecium over long distances. Intergenic regions are highly constrained relative to coding sequences, especially in P. caudatum and P. multimicronucleatum that have shorter intergenic distances. Sequence diversity and divergence are reduced up to ∼100-150 bp both upstream and downstream of genes, suggesting strong constraints imposed by the presence of densely packed regulatory modules. In addition, comparison of sequence variation at non-synonymous and synonymous sites suggests similar recent selective pressures on paralogs within and orthologs across the deeply diverging species. This study presents the first genome-wide population-genomic analysis in ciliates and provides a valuable resource for future studies in evolutionary and functional genetics in Paramecium. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Ageing populations: the challenges ahead

    DEFF Research Database (Denmark)

    Christensen, Kaare; Doblhammer, Gabriele; Rau, Roland

    2009-01-01

    If the pace of increase in life expectancy in developed countries over the past two centuries continues through the 21st century, most babies born since 2000 in France, Germany, Italy, the UK, the USA, Canada, Japan, and other countries with long life expectancies will celebrate their 100th...... birthdays. Although trends differ between countries, populations of nearly all such countries are ageing as a result of low fertility, low immigration, and long lives. A key question is: are increases in life expectancy accompanied by a concurrent postponement of functional limitations and disability...

  8. Measuring happiness in large population

    Science.gov (United States)

    Wenas, Annabelle; Sjahputri, Smita; Takwin, Bagus; Primaldhi, Alfindra; Muhamad, Roby

    2016-01-01

    The ability to know emotional states for large number of people is important, for example, to ensure the effectiveness of public policies. In this study, we propose a measure of happiness that can be used in large scale population that is based on the analysis of Indonesian language lexicons. Here, we incorporate human assessment of Indonesian words, then quantify happiness on large-scale of texts gathered from twitter conversations. We used two psychological constructs to measure happiness: valence and arousal. We found that Indonesian words have tendency towards positive emotions. We also identified several happiness patterns during days of the week, hours of the day, and selected conversation topics.

  9. SOCIAL EXCLUSION AND VULNERABLE POPULATIONS

    Directory of Open Access Journals (Sweden)

    ROXANA PLEŞA

    2013-12-01

    Full Text Available In the last half of the century, significant technological, economic, demographic, political, and ideological changes took place; advanced democracies went to a process of deep economic restructurings. While universal social policies still provide for protection against predictable risks of a life cycle, individual carrier models and welfare standardization can no longer be assumed. There are more and more people suffering from insecurity, or lacking protection of any kind. Excluded populations are therefore more affected than any other categories of social actors and their poverty is more obvious; in a certain sense, it is less “natural” than it has ever been.

  10. Nonlinear dynamics of interacting populations

    CERN Document Server

    Bazykin, Alexander D

    1998-01-01

    This book contains a systematic study of ecological communities of two or three interacting populations. Starting from the Lotka-Volterra system, various regulating factors are considered, such as rates of birth and death, predation and competition. The different factors can have a stabilizing or a destabilizing effect on the community, and their interplay leads to increasingly complicated behavior. Studying and understanding this path to greater dynamical complexity of ecological systems constitutes the backbone of this book. On the mathematical side, the tool of choice is the qualitative the

  11. Bacterial computing with engineered populations.

    Science.gov (United States)

    Amos, Martyn; Axmann, Ilka Maria; Blüthgen, Nils; de la Cruz, Fernando; Jaramillo, Alfonso; Rodriguez-Paton, Alfonso; Simmel, Friedrich

    2015-07-28

    We describe strategies for the construction of bacterial computing platforms by describing a number of results from the recently completed bacterial computing with engineered populations project. In general, the implementation of such systems requires a framework containing various components such as intracellular circuits, single cell input/output and cell-cell interfacing, as well as extensive analysis. In this overview paper, we describe our approach to each of these, and suggest possible areas for future research. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  12. A Tale of Two Populations

    Science.gov (United States)

    2005-03-01

    VLT FLAMES Finds Hints of Helium-Richest Stars Ever Seen Summary On the basis of stellar spectra totalling more than 200 hours of effective exposure time with the 8.2-m VLT Kueyen telescope at Paranal (Chile), a team of astronomers [1] has made a surprising discovery about the stars in the giant southern globular cluster Omega Centauri. It has been known for some time that, contrary to other clusters of this type, this stellar cluster harbours two different populations of stars that still burn hydrogen in their centres. One population, accounting for one quarter of its stars, is bluer than the other. Using the FLAMES multi-object spectrograph that is particularly well suited to this kind of work, the astronomers found that the bluer stars contain more heavy elements than those of the redder population. This was exactly opposite to the expectation and they are led to the conclusion that the bluer stars have an overabundance of the light element helium of more than 50%. They are in fact the most helium rich stars ever found. But why is this so? The team suggests that this puzzle may be explained in the following way. First, a great burst of star formation took place during which all the stars of the red population were produced. As other normal stars, these stars transformed their hydrogen into helium by nuclear burning. Some of them, with masses of 10-12 times the mass of the Sun, soon thereafter exploded as supernovae, thereby enriching the interstellar medium in the globular cluster with helium. Next, the blue population stars formed from this helium-rich medium. This unexpected discovery provides important new insights into the way stars may form in larger stellar systems. PR Photo 08a/05: The Omega Centauri Globular Cluster and the Area Surveyed (DSS and ACS/HST) PR Photo 08b/05: The Double Main Sequence of Omega Centauri PR Photo 08c/05: Average Spectra of the Blue and Red Population Stars (FLAMES + VLT) PR Photo 08d/05: The Supernova Scenario Two Populations

  13. Optimal Population and Exhaustible Resource Constraints.

    Science.gov (United States)

    Lawson, Nicholas; Spears, Dean

    2018-01-01

    A large literature considers the optimal size and growth rate of the human population, trading off the utility value of additional people with the costs of a larger population. In this literature, an important parameter is the social weight placed on population size; a standard result is that a planner with a larger weight on population chooses larger population levels and growth rates. We demonstrate that this result is conditionally overturned when an exhaustible resource constraint is introduced: if the discount rate is small enough, the optimal population today decreases with the welfare weight on population size. That is, a more total-utilitarian social planner could prefer a smaller population today than a more average-utilitarian social planner. We also present a numerical illustration applied to the case of climate change, where we show that under plausible real-world parameter values, our result matters for the direction and magnitude of optimal population policy.

  14. Who fears and who welcomes population decline?

    Directory of Open Access Journals (Sweden)

    Hendrik P. Van Dalen

    2011-08-01

    Full Text Available European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment as well as material welfare losses (tax increases, economic stagnation. In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline.

  15. Symbolic trephinations and population structure

    Directory of Open Access Journals (Sweden)

    László Szathmáry

    2006-12-01

    Full Text Available The sample examined consists of 19 skulls with symbolic trephinations and 86 skulls without trepanations dated from the X century. Skulls were all excavated in the Great Hungarian Plain in the Carpathian Basin, which was occupied by the Hungarian conquerors at the end of the IX century. The variations of 12 cranial dimensions of the trephined skulls were investigated and compared to the skulls without trepanations after performing a discriminant analysis. The classification results evince that the variability of non-trephined skulls shows a more homogeneous and a more characteristic picture of their own group than the trephined samples, which corresponds to the notion, formed by archaeological evidence and written historical sources, of a both ethnically and socially differing population of the Hungarian conquerors. According to historical research, a part of the population was of Finno-Ugric origin, while the military leading layer of society can be brought into connection with Turkic ethnic groups. All the same, individuals dug up with rich grave furniture and supposed to belong to this upper stratum of society are primarily characterized by the custom of symbolic trephination, and, as our results demonstrate, craniologically they seem to be more heterogeneous.

  16. Paraguay: population and the economy.

    Science.gov (United States)

    Sanders, T G

    1986-01-01

    Paraguay's political conflicts and development experiences have been accompanied by compensatory population movements; however, economic and population policies of the past are not adequate to address the current economic challenges. The principal structural problem is dependence on international commodity prices. Since late 1984, the international prices for soya and cotton have declined more than 50%; these 2 products account for 83% of official exports. The external debt has grown significantly in the past 5 years and is increasingly difficult to service. A major problem the government faces in servicing the debt and maintaining economic growth is its inability to get control of foreign exchange. Much of Paraguay's external trade is contraband, with the dollars passing into the black market. As a result of the illegal economy, government earnings have been insufficient to cover expenses. Unemployment stands at 12% because of general economic decline, cuts in government expenditure, and the reduction of investment in hydroelectricity. Occupation of new land, the classic solution by the Paraguayan peasantry, is no longer a viable option since all land is now utilized. About 20-25% of Paraguayans live outside the country, expecially in Argentina. In 1986, a commission drafted an Adjustment Plan that recommended a devaluation of the official gurani rate, tax increases, higher tariffs for public services, and incentives to invest in priority areas; however, this plan has not been implemented to date.

  17. Social exclusion in finite populations

    Science.gov (United States)

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.

  18. Diversity of aquatic bacterial populations

    International Nuclear Information System (INIS)

    Teska, J.D.

    1988-01-01

    A study was designed to evaluate the feasibility of adapting the automated Quantum II for the identification of bacterial fish pathogens. Optimal incubation conditions were determined for each of the species used, and, by using a Chi-square goodness of fit test, it was shown that isolates could be sorted into like-species groups with a Ward's hierarchical cluster analysis technique. In a second study, population profiles, growth kinetics, and transformation kinetics were evaluated for bacteria isolated from 4 aquatic environments located in the southeastern United States. Gradual long-term accumulation of organic acids in the waters of the Okefenokee Swamp, located in southeast Georgia and northeast Florida, has resulted in acidic water ranging from pH 3.5 to 4.5. A study was designed to evaluate the metabolic efficiency of surface-water gram-negative nonfermentative bacteria and ascertain whether aquatic bacterial populations exhibit adaptation to the low pH conditions. Using the computerized AMBIS the uptake and incorporation of 35 S-methionine into bacterial proteins under 5 levels of pH was quantitated for each of the test organisms

  19. Salmonella Populations inside Host Cells

    Directory of Open Access Journals (Sweden)

    Sónia Castanheira

    2017-10-01

    Full Text Available Bacteria of the Salmonella genus cause diseases ranging from gastroenteritis to life-threatening typhoid fever and are among the most successful intracellular pathogens known. After the invasion of the eukaryotic cell, Salmonella exhibits contrasting lifestyles with different replication rates and subcellular locations. Although Salmonella hyper-replicates in the cytosol of certain host cell types, most invading bacteria remain within vacuoles in which the pathogen proliferates at moderate rates or persists in a dormant-like state. Remarkably, these cytosolic and intra-vacuolar intracellular lifestyles are not mutually exclusive and can co-exist in the same infected host cell. The mechanisms that direct the invading bacterium to follow the cytosolic or intra-vacuolar “pathway” remain poorly understood. In vitro studies show predominance of either the cytosolic or the intra-vacuolar population depending on the host cell type invaded by the pathogen. The host and pathogen factors controlling phagosomal membrane integrity and, as consequence, the egress into the cytosol, are intensively investigated. Other aspects of major interest are the host defenses that may affect differentially the cytosolic and intra-vacuolar populations and the strategies used by the pathogen to circumvent these attacks. Here, we summarize current knowledge about these Salmonella intracellular subpopulations and discuss how they emerge during the interaction of this pathogen with the eukaryotic cell.

  20. Mantel test in population genetics.

    Science.gov (United States)

    Diniz-Filho, José Alexandre F; Soares, Thannya N; Lima, Jacqueline S; Dobrovolski, Ricardo; Landeiro, Victor Lemes; de Campos Telles, Mariana Pires; Rangel, Thiago F; Bini, Luis Mauricio

    2013-12-01

    The comparison of genetic divergence or genetic distances, estimated by pairwise FST and related statistics, with geographical distances by Mantel test is one of the most popular approaches to evaluate spatial processes driving population structure. There have been, however, recent criticisms and discussions on the statistical performance of the Mantel test. Simultaneously, alternative frameworks for data analyses are being proposed. Here, we review the Mantel test and its variations, including Mantel correlograms and partial correlations and regressions. For illustrative purposes, we studied spatial genetic divergence among 25 populations of Dipteryx alata ("Baru"), a tree species endemic to the Cerrado, the Brazilian savannas, based on 8 microsatellite loci. We also applied alternative methods to analyze spatial patterns in this dataset, especially a multivariate generalization of Spatial Eigenfunction Analysis based on redundancy analysis. The different approaches resulted in similar estimates of the magnitude of spatial structure in the genetic data. Furthermore, the results were expected based on previous knowledge of the ecological and evolutionary processes underlying genetic variation in this species. Our review shows that a careful application and interpretation of Mantel tests, especially Mantel correlograms, can overcome some potential statistical problems and provide a simple and useful tool for multivariate analysis of spatial patterns of genetic divergence.

  1. Reconstructing Native American population history.

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C; Bravi, Claudio M; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria Cátira; Salzano, Francisco M; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, Maria José; Molina, Julio; Carracedo, Angel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B; Alkorta-Aranburu, Gorka; Sukernik, Rem I; Osipova, Ludmila; Fedorova, Sardana A; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean-Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Di Rienzo, Anna; Freimer, Nelson B; Price, Alkes L; Ruiz-Linares, Andrés

    2012-08-16

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.

  2. Reconstructing Native American Population History

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V.; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F.; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C.; Bravi, Claudio M.; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria-Cátira; Salzano, Francisco M.; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V.; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, María José; Molina, Julio; Carracedo, Ángel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B.; Alkorta-Aranburu, Gorka; Sukernik, Rem I.; Osipova, Ludmila; Fedorova, Sardana; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Rienzo, Anna Di; Freimer, Nelson B.; Price, Alkes L.; Ruiz-Linares, Andrés

    2013-01-01

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America. PMID:22801491

  3. Population explosion and population control programmes in Bangladesh: an overview.

    Science.gov (United States)

    Rahman, A S; Nazneen, D R

    1992-01-01

    "The authors discuss in detail efforts made by [the] Bangladesh Government to control its population through planned efforts since 1953. Covering persistent setbacks and reasons thereof in governmental efforts, the authors highlight shifts in policies and strategy.... The [government family planning] programme provides a wide range of contraceptive choice to eligible couples in a manner as acceptable and convenient as possible to the client. The programme is totally voluntary and the government is firmly opposed to coercion or pressure on couples to accept contraception. As a strategy, the programme has integrated health and [family planning] while various ministries have attempted to encourage the acceptance of low-fertility behaviour through socio-economic incentives and educational motivation programmes." excerpt

  4. Population change and educational development.

    Science.gov (United States)

    Jayasuriya, J E

    1982-06-01

    The 4 principal conditions of a stable society are: 1) minimum disruption of ecological processes, 2) maximum conservation of material and energy or an economy of stock rather than flow, 3) a population in which recruitment equals loss, and 4) a social system in which individuals can enjoy rather than be restricted by the 1st 3 conditions. In 1960 the developing countries set goals relating to education including the achievement of universal primary education, the eradication of illiteracy, and the provision of secondary and tertiary education to meet manpower needs. The countries with the highest enrollment ratios in 1980 were Korea, 100%, Singapore, 100%, Malaysia, 94%, Philippines 80.6%, Thailand, 77.8%, and Iran 75.5%. Eradication of illiteracy has not been reached since by 1990 Afghanistan, India, Nepal, and Pakistan will have illiteracy rates of over 50% and as a result of increases in the absolute number of illiterates over the period of 1970-90 in Afghanistan, Bangladesh, India, Nepal, and Pakistan, the number of illiterates in the developing countries of Asia will increase from 339.1 million in 1970 to 425.6 million in 1990. The females and rural population are especially disadvantaged groups in terms of education; 98.4% of rural females are illiterate as compared to 63.8% of urban males and in Iran 91.7% of rural females compared with 31.3% of urban males are illiterate. One reason for shortfalls in the achievement of educational goals is rapid population growth, especially of school-age groups; for instance the total population aged 6-11 in Indonesia increased by 89.3%. In a study on the Philippines conducted in 1975 it was found that, for the series of high projections, the schedule of age-specific fertility rates observed for 1968-72 resulting in a total fertility rate of 5.89 would remain constant throughout the projection period, the death rate would decline by 4.8 points, international migration would remain negligible; for the low projections

  5. Gridded Population of the World, Version 4 (GPWv4): Administrative Unit Center Points with Population Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 4 (GPWv4) Administrative Unit Center Points with Population Estimates consists of UN-adjusted estimates of human population...

  6. Gridded Population of the World, Version 4 (GPWv4): Population Density

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 4 (GPWv4) Population Density consists of estimates of human population density based on counts consistent with national...

  7. Gridded Population of the World, Version 4 (GPWv4): Population Density, Revision 10

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 4 (GPWv4) Population Density, Revision 10 consists of estimates of human population density (number of persons per square...

  8. Gridded Population of the World, Version 4 (GPWv4): Population Count, Revision 10

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 4 (GPWv4) Population Count, Revision 10 consists of estimates of human population (number of persons per pixel), consistent...

  9. Population momentum across vertebrate life histories

    Science.gov (United States)

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  10. Heterotrophic bacterial populations in tropical sandy beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; LokaBharathi, P.A.

    Distribution pattern of heterotrophic bacterial flora of three sandy beaches of the west coast of India was studied. The population in these beaches was microbiologically different. Population peaks of halotolerant and limnotolerant forms were...

  11. Measuring populations to improve vaccination coverage

    Science.gov (United States)

    Bharti, Nita; Djibo, Ali; Tatem, Andrew J.; Grenfell, Bryan T.; Ferrari, Matthew J.

    2016-10-01

    In low-income settings, vaccination campaigns supplement routine immunization but often fail to achieve coverage goals due to uncertainty about target population size and distribution. Accurate, updated estimates of target populations are rare but critical; short-term fluctuations can greatly impact population size and susceptibility. We use satellite imagery to quantify population fluctuations and the coverage achieved by a measles outbreak response vaccination campaign in urban Niger and compare campaign estimates to measurements from a post-campaign survey. Vaccine coverage was overestimated because the campaign underestimated resident numbers and seasonal migration further increased the target population. We combine satellite-derived measurements of fluctuations in population distribution with high-resolution measles case reports to develop a dynamic model that illustrates the potential improvement in vaccination campaign coverage if planners account for predictable population fluctuations. Satellite imagery can improve retrospective estimates of vaccination campaign impact and future campaign planning by synchronizing interventions with predictable population fluxes.

  12. Trismus in the paediatric population.

    Science.gov (United States)

    Shires, Peter M; Chow, Gabriel

    2015-04-01

    Trismus is a rare presentation affecting neonates, children, and adults. In newborns there are serious implications, with potential to affect feeding, cause airway problems, and make intubation difficult. Causes of trismus seen in the paediatric patient are discussed in this review article; they are divided into intra- and extra-articular types. The extra-articular group consists of congenital and acquired disorders. The acquired group includes infective causes such as tetanus, iatrogenic causes related to drugs, cancer or dental treatment, and trauma causing articulation difficulty or triggering a rare type of bone growth in myositis ossificans. Changes in the mouth resulting from oral submucous fibrosis can undergo malignant transformation. This review aims to raise awareness of potential causes of trismus in paediatric populations, helping clinicians identify the underlying pathology so appropriate strategies for treatment be applied, with the ultimate aim of improving long-term outlook and quality of life for affected children. © 2014 Mac Keith Press.

  13. Raltegravir use in special populations.

    Science.gov (United States)

    Johnson, Margaret

    2009-11-24

    Raltegravir, the first approved integrase inhibitor, has been shown to be virologically effective in Phase II and Phase III clinical trials in both treatment naive and triple class resistant patients. It also has an excellent tolerability profile and lacks significant drug-drug interactions making it an important drug in the treatment of a number of special patient populations. In this review its use in patients undergoing solid organ and bone marrow transplantation and patients receiving cancer chemotherapy, will be discussed. In addition other indications including patients with metabolic complications of existing antiretroviral drugs as well as patients with side effects on current HAART regimens. Other groups of patients where raltegravir may play an important role are patients with renal disease and tuberculosis. Finally, although not licensed for use in pregnancy, raltegravir may need to be considered in some pregnant women with antiretroviral resistance or tolerability issues with current HAART regimens.

  14. Raltegravir use in special populations

    Directory of Open Access Journals (Sweden)

    Johnson Margaret

    2009-11-01

    Full Text Available Abstract Raltegravir, the first approved integrase inhibitor, has been shown to be virologically effective in Phase II and Phase III clinical trials in both treatment naïve and triple class resistant patients. It also has an excellent tolerability profile and lacks significant drug-drug interactions making it an important drug in the treatment of a number of special patient populations. In this review its use in patients undergoing solid organ and bone marrow transplantation and patients receiving cancer chemotherapy, will be discussed. In addition other indications including patients with metabolic complications of existing antiretroviral drugs as well as patients with side effects on current HAART regimens. Other groups of patients where raltegravir may play an important role are patients with renal disease and tuberculosis. Finally, although not licensed for use in pregnancy, raltegravir may need to be considered in some pregnant women with antiretroviral resistance or tolerability issues with current HAART regimens.

  15. Population dynamics in vasopressin cells.

    Science.gov (United States)

    Leng, Gareth; Brown, Colin; Sabatier, Nancy; Scott, Victoria

    2008-01-01

    Most neurons sense and code change, and when presented with a constant stimulus they adapt, so as to be able to detect a fresh change. However, for some things it is important to know their absolute level; to encode such information, neurons must sustain their response to an unchanging stimulus while remaining able to respond to a change in that stimulus. One system that encodes the absolute level of a stimulus is the vasopressin system, which generates a hormonal signal that is proportional to plasma osmolality. Vasopressin cells sense plasma osmolality and secrete appropriate levels of vasopressin from the neurohypophysis as needed to control water excretion; this requires sustained secretion under basal conditions and the ability to increase (or decrease) secretion should plasma osmolality change. Here we explore the mechanisms that enable vasopressin cells to fulfill this function, and consider how coordination between the cells might distribute the secretory load across the population of vasopressin cells. 2008 S. Karger AG, Basel.

  16. [Genetic structure of natural populations

    International Nuclear Information System (INIS)

    1988-01-01

    Our efforts in the first eight months were concentrated in obtaining a genomic clone of the copper-zinc superoxide dismutase (SOD) in Drosophila melanogaster and other Drosophila species. This we have now successfully accomplished. We seek to understand the role of SOD in radioresistance; how genetic variation in this enzyme is maintained in populations; and relevant aspects of its evolution that may contribute to these goals as well as to an understanding of molecular evolution in general. To accomplish these goals we are undertaking the following experiments: cloning and sequencing of (at least) one F allele, one S allele, and the null allele for SOD; cloning and sequencing SOD from species related to D. melanogaster; and cloning and sequencing the SOD gene from several independently sampled S and F alleles in D. melanogaster. We are also preparing to test the radioprotective effects of SOD. 67 refs

  17. Quantitative variation in natural populations

    International Nuclear Information System (INIS)

    Parsons, P.A.

    1975-01-01

    Quantitative variation is considered in natural populations using Drosophila as the example. A knowledge of such variation enables its rapid exploitation in directional selection experiments as shown for scutellar chaeta number. Where evidence has been obtained, genetic architectures are in qualitative agreement with Mather's concept of balance for traits under stabilizing selection. Additive genetic control is found for acute environmental stresses, but not for less acute stresses as shown by exposure to 60 Co-γ rays. D. simulans probably has a narrower ecological niche than its sibling species D. melanogaster associated with lower genetic heterogeneity. One specific environmental stress to which D. simulans is sensitive in nature is ethyl alcohol as shown by winery data. (U.S.)

  18. Population Dynamics and Air Pollution

    DEFF Research Database (Denmark)

    Flachs, Esben Meulengracht; Sørensen, Jan; Bønløkke, Jacob

    2013-01-01

    Objective. To explore how three different assumptions on demographics affect the health impact of Danish emitted air pollution in Denmark from 2005 to 2030, with health impact modeled from 2005 to 2050. Methods. Modeled air pollution from Danish sources was used as exposure in a newly developed......) a static year 2005 population, (2) morbidity and mortality fixed at the year 2005 level, or (3) an expected development. Results. The health impact of air pollution was estimated at 672,000, 290,000, and 280,000 lost life years depending on demographic assumptions and the corresponding social costs at 430.......4 M€, 317.5 M€, and 261.6 M€ through the modeled years 2005–2050. Conclusion. The modeled health impact of air pollution differed widely with the demographic assumptions, and thus demographics and assumptions on demographics played a key role in making health impact assessments on air pollution....

  19. Population commission discusses international migration.

    Science.gov (United States)

    1997-01-01

    At the 30th session of the Commission on Population and Development during February 24-28, 1997, international migration was the main topic, with special linkages between migration and development and on gender issues and the family. New and emerging issues were also considered. Members stressed the need for more reliable data on migration, the direction of migrants flows, and the characteristics of migrants. The Commission requested a task force on basic social services to hold a technical symposium of experts on international migration in 1998. Its chair, Dr. Nafis Sadik, said that migration issues should based on the reality of choice not on coercive measures or quotas. Almost half of the migrants globally are women. The Commission was given a new impetus by the International Conference on Population and Development held at Cairo in 1994. Migration pressures intensified in the second half of the 1980s and in the early 1990s, creating areas of concern: the negative impact of short-term migration on working conditions in host countries; migration pressures emanating from climatic change; the protection of migrant women and their children; the right of receiving countries to regulate access to their territory; the adverse consequences of forced migration; the situation of persons whose asylum claims have been rejected; the trafficking in women and children, prostitution and coercive adoption; and the sudden and massive arrival of refugees in need of international protection. The 1998 session of the Commission will feature the theme of health and mortality, with special emphasis on the linkages between health and development and on gender and age.

  20. Population Pharmacokinetics of Intranasal Scopolamine

    Science.gov (United States)

    Wu, L.; Chow, D. S. L.; Putcha, L.

    2013-01-01

    Introduction: An intranasal gel dosage formulation of scopolamine (INSCOP) was developed for the treatment of Space Motion Sickness (SMS).The bioavailability and pharmacokinetics (PK) was evaluated using data collected in Phase II IND protocols. We reported earlier statistically significant gender differences in PK parameters of INSCOP at a dose level of 0.4 mg. To identify covariates that influence PK parameters of INSCOP, we examined population covariates of INSCOP PK model for 0.4 mg dose. Methods: Plasma scopolamine concentrations versus time data were collected from 20 normal healthy human subjects (11 male/9 female) after a 0.4 mg dose. Phoenix NLME was employed for PK analysis of these data using gender, body weight and age as covariates for model selection. Model selection was based on a likelihood ratio test on the difference of criteria (-2LL). Statistical significance for base model building and individual covariate analysis was set at P less than 0.05{delta(-2LL)=3.84}. Results: A one-compartment pharmacokinetic model with first-order elimination best described INSCOP concentration ]time profiles. Inclusion of gender, body weight and age as covariates individually significantly reduced -2LL by the cut-off value of 3.84(P less than 0.05) when tested against the base model. After the forward stepwise selection and backward elimination steps, gender was selected to add to the final model which had significant influence on absorption rate constant (ka) and the volume of distribution (V) of INSCOP. Conclusion: A population pharmacokinetic model for INSCOP has been identified and gender was a significant contributing covariate for the final model. The volume of distribution and Ka were significantly higher in males than in females which confirm gender-dependent pharmacokinetics of scopolamine after administration of a 0.4 mg dose.