WWW.DISSERTATION.XLIBX.INFO
FREE ELECTRONIC LIBRARY - Dissertations, online materials
 
<< HOME
CONTACTS



Pages:     | 1 |   ...   | 31 | 32 || 34 | 35 |   ...   | 36 |

«: AGROCHEMICALS: FATE IN FOOD AND THE ENVIRONMENT PROCEEDINGS OF A SYMPOSIUM, ROME, 7 - 1 1 JUNE 1982 JOINTLY ORGANIZED BY IAEA AND FAO l^J I N T E R ...»

-- [ Page 33 ] --

With the present stress on higher agricultural production it is now necessary to use higher levels o f fertilizers and also diverse pesticides to control various insect pests, disease fungi and weeds, it is considered probable that these chemical compounds may affect the various nitrogen-fixing organisms in these potentially fertile soils. Earlier unpublished studies have indicated that these agrochemicals had a deleterious effect on some o f the nitrogen-fixing blue-green algae. In 1981 Khider [3] carried out a trial using four insecticides, nogos, kelthane, melathion and diptrex, and three fungicides, robigan, benlate and sulphur powder, on a local strain o f R. leguminosarum. He found that higher doses o f almost all the pesticides, when applied to the nutrient culture medium containing a known count o f the rhizobia, lowered the count to a significant level.

A series o f experiments have been carried out by the authors on the following soil nitrogen-fixing organisms isolated from different locations in north Iraq: Azotobacter spp. and chroococcum, A. vinelandii, Nostoc 307 (Obtained from Nitragan Co., Milwaukee, USA). The R. leguminosarum various pesticides used were diptrex, melathion, kelthane and parathion. These agrochemicals were used at four doses, namely 0.1, 1.0, 4.0 and 8.0 ml per litre o f medium, on the basis o f active ingredients o f the respective pesticides.

The results o f the experiments can be summarized as follows:

(1) Both A. chroococcum and A. vinelandii were found to be suppressed by the insecticides at all the levels used, but fungicides caused injury at high doses only. When medium doses were applied the organisms regained their usual growth pattern after 20 d incubation. It is thought that the organisms probably metabolized these agrochemicals.

(2) Growth o f Nostoc spp. was very significantly affected by all the pesticides.

However, even with high doses o f different pesticides, it was noted that organisms regained their usual growth pattern when removed from the media containing the agrochemicals.

(3) 307 was found to be quite tolerant to all the pesticides R, leguminosarum used, but at high doses the growth o f the organisms was very markedly influenced and in most cases irreversibly. Respiration studies using

POSTER PRESENTATIONS

1 4 C-glucose [ 5 ] indicated that glucose oxidation was inhibited in consonance with the doses o f the insecticides. The behaviour o f fungicides was not clear.

–  –  –

[1] KHAN, M.F.A., Preliminary investigations on microbial counts of representative soils of North Iraq, unpublished Draft Report, 1974.

HAMZA, S.J., Study of nitrogen fixation by some species of Azotobacter [2] in Sulaimaniyah, M.Sc. Thesis, University of Sulaimaniyah, Iraq, 1978.

KHIDER, A.K., A study of root-nodule bacteria (Rhizobium leguminosarum) on [3] broadbean in some Northern Iraqi soils, M.Sc. Thesis, University of Sulaimaniyah, Iraq, 1981.

[4] KHAN, M.F.A., ARMAGHANI, F.A., AZIZ, N.A., Study of blue-green algae in soils of the Sulaimaniyah Valley with special reference to nitrogen fixation and mineral nutrition, Sci. J. Sulaim. Univ. (A) 3 (1977) 237.

[5] INTERNATIONAL ATOMIC ENERGY AGENCY, Tracer Manual on Crops and Soils, Technical Reports Series No. 171, IAEA, Vienna (1976).

IAEA-SM-263/19

EFFECT O F G A M M A IRRADIATION

O N PESTICIDE RESIDUES

IN F O O D P R O D U C T S

S. B A C H M A N, J. G I E S Z C Z Y N S K A Laboratory o f F o o d Irradiation Institute o f Applied Radiation Chemistry, Technical University,

-Lódz, Poland Use o f chemicals in agriculture results in many cases in the appearance o f terminal residues in f o o d products. This study was undertaken to determine the e f f e c t o f ionizing irradiation o n the magnitude and nature o f pesticide residues in f o o d products and m o d e l systems. For this purpose gamma irradiation f r o m 60Co was used at doses normally applied for f o o d preservation, as well as doses higher than 50 kGy. Lindane, m e t h o x y c h l o r and carbaryl were irradiated in a solid-state or in hexane solutions at concentrations o f 4—5 p p m f o r the chlorinated hydrocarbons and 1 p p m for carbaryl. F o o d included luncheon meat and onions.

POSTER PRESENTATIONS

–  –  –

The chemicals were mixed with the meat by dissolving in purified lard to provide pesticide levels at the concentrations indicated above. Animal feed included bone meat, blood and fish meals. At 30 kGy chemical degradation in model systems amounted to 24% for the organochlorine pesticides and 40% for carbaryl (Table I).

Pesticide residues in luncheon meat did not suffer any apparent degradation when exposed to a dose range o f 25—48 kGy. Normally occurring residues o f p,p'-DDT (0.05 p p m ) in onions were not affected at doses o f 4 0 - 8 0 Gy. On the other hand, sterilizing doses o f 2 5 - 5 0 kGy resulted in a reduction of lindane residues o f 0.038 ppm in bone-meat meal to 0. 0 0 0 2 - 0. 0 1 6 ppm (Fig.l). In this case, sterilization by gamma irradiation may provide the additional advantages of degrading and possibly detoxifying chemical residues.

IAEA-SM-263/56

A COMPARATIVE STUDY OF THE NITROGEN





METABOLISM OF PHYTOPLANKTON A N D

PERIPHYTON IN A SUB-ALPINE LAKE*

R.P. A X L E R, C.R. GOLDMAN, J.E. REUTER, S.L. LOEB, J.C. PRISCU, R.G. CARLTON Division of Environmental Studies, Institute o f Ecology, University o f California, Davis, California, United States o f America Current limnological research in meso-oligotrophic Castle Lake, California, USA, has emphasized the effects o f nutrient enrichment and deficiency on primary producers. Nitrogen availability, in particular, has been shown to regulate rates o f nitrogen uptake and primary production during a major portion o f the growing season [ 1 - 5 ]. Beginning in 1980, the programme was expanded to include studies o f benthic communities (eulittoral, sublittoral, and epipelic periphyton) and whole-epilimnion enrichments with N H 4 N 0 3 ( + 7 5 jug N - Г 1 ) to more fully delineate the effects o f increased N-loading on different algal communities c o existing within the same lake.

–  –  –

in a variety o f physiological assays, the results o f which could then be compared with actual in-lake responses.

At the time o f writing some o f the data sets remain incompletely analysed;

however, we are able to provide preliminary interpretations o f our findings.

Phytoplankton rates o f primary production in 1980 exhibited essentially n o effect to epilimnetic enrichment f o r a period o f about 12 d, after which rates rapidly increased by m o r e than 300%. However, in 1981, a year in which mid-summer phytoplankton productivity was 4 0 0 - 5 0 0 % higher than in 1980, rates o f 14C primary productivity (PPr) increased rapidly to a level approximately 60% above the pre-spike rate after one week (Fig. 1). Large ( 5 0 0 0 1) polyethylene tube enclosures containing pre-spike water remained near pre-spike values during this period, and paralleled open-lake rates o f primary production f o r the duration of.

the experiment, although at lower values. Replicate 'N'- tubes tracked the openlake with regard to DIN concentrations f o r 2 0 d (depletion), but did so f o r only 7—10 d with regard to 14 C-PPr. An obvious conclusion is that large volume enclosures d o not necessarily simulate open-lake production processes f o r extended periods o f time.

Chemical analyses following the enrichment showed that ammonium and nitrate depletion proceeded linearly with time (Fig. 2), in accordance with Michaelis-Menten kinetics and a low ( K { ~ 5 MgN- Г 1 ) half-saturation constant.

Furthermore, N 0 3 decreased at a rate o f only about 6 0 % o f the NH 4 removal rate. Although this preferential NH 4 uptake is in general agreement with numerous studies [6], previous shorter-term 1S N and 13N experiments using Castle Lake water had indicated that N 0 3 uptake occurred at rates o f about 1 - 5 % o f that f o r NH 4 [4,7]. This suggests that nitrate reductase activity was induced over a period o f days following whole-lake enrichment.

Our studies o f nitrogen cycling in Castle Lake have n o w delineated five distinct communities o f algae, which differ with regard to their sources o f available nitrogen. Briefly, these are: ( 1 ) upper euphotic z o n e phytoplankton, which have high affinity f o r l o w levels o f DIN (half-saturation constants for N-uptake, K j 10 ^ g N - Г 1 ) ; ( 2 ) lower euphotic z o n e ( ~ 1% surface light) phytoplankton, which are located immediately above aphotic b o t t o m waters (higher DIN) and have K t s in the range o f 20-80 /igN- Г 1 ; ( 3 ) eulittoral (splash z o n e ) epilithic periphyton, which lack the ability to fix atmospheric nitrogen and have a K t f o r N H 4 - N o f 175 MgN-1" 1 (and 162 M g [ N 0 3 - N ] - l _ 1 in ultra-oligotrophic 318 POSTER PRESENTATIONS

–  –  –

[1] GOLDMAN, C.R., Mitt. Int. Ver. Limnol. 21 (1978) 364.

[2] AXLER, R.P., REDFIELD, G.W., GOLDMAN, C.R., Ecology 62 (1981) 345.

[3] AXLER, R.P., GOLDMAN, C.R., Wat. Res. 15 ( 1 9 8 1 ) 6 2 7.

[4] GERSBERG, R.M., AXLER, R.P., GOLDMAN, C.R., "Isotope studies of nitrogen transformations in Castle Lake, California", Agrochemical Residue-Biota Interactions in Soil and Aquatic Ecosystems, (Proc. Panel Vienna, 1978), IAEA, Vienna (1980) 75.

[5] LOEB, S.L., REUTER, J.F., Verh. Int. Ver. Angew. Limnol. 21 (1981) 346.

[6] MCCARTHY, J. J., The Physiological Ecology of Phytoplankton (MORRIS, T., Ed.), Univ. of California Press (1980) 191.

[7] AXLER, R.P., GERSBERG, R.M., GOLDMAN, C.R., Limnol. Oceanogr. (in press).

IAEA-SM-263/52

ИЗУЧЕНИЕ ДЕЙСТВИЯ

РАЗЛИЧНЫХ ЗАГРЯЗНИТЕЛЕЙ ВОДНОЙ СРЕДЫ

НА ГИДРОФИТЫ

ЕтД. МАРЧЮЛЕНЕНЕ, Э.Б. МОТЕЮНЕНЕ

Институт ботаники Академии наук Литовской ССР, Вильнюс, Союз Советских Социалистических Республик Роль различных химических веществ в загрязнении водоемов в первую очередь оценивается по их воздействию на важнейшие функции организмов, в частности, на их рост, развитие, размножение, ионный и энергетический обмены со средой, а также по генетическому действию этих веществ. Состояние ионного и энергетического обменов со средой в растительных клетках отражают мембранные потенциалы, проницаемость клеточных мембран и скорость движения протоплазмы. Эти параметры могут быть использованы как экспресс-показатели функционального состояния клеток при загрязнении водной среды. Одним из основных биологических процессов растительной POSTER PRESENTATIONS 319 клетки является фотосинтез, который обеспечивает ее рост и развитие. Генетический эффект, вызываемый в популяциях одноклеточных водорослей различными загрязнителями, в том числе и радионуклидами, можно оценить по числу мутантных и летально поврежденных клеток.

Целью настоящей работы явилось изучить: действие различных концентраций РЬ, сточных вод целлюлозно-бумажного производства (ЦБП) и ДДТ на физиологическое состояние водорослей, которое оценивали по мембранным потенциалам (МП), скорости движения протоплазмы и выживаемости их клеток, действие термального загрязнения на физиологическое состояние водорослей, которое оценивали по подвижности протоплазмы и выживаемости клеток, а также на уровни накопления радионуклидов в водных растениях, и действие радионуклидов на популяции хлореллы, состояние которой оценивали по плотности клеток, интенсивности фотосинтеза и числу мутанных и летально поврежденных клеток.

РЬ при концентрациях 0,02 и 0,2 мг/л оказывает незначительное отрицательное влияние на клетки водорослей Nitellopsis obtusa, вызывая небольшую деполяризацию мембран, а при концентрации 2,0 мг/л уменьшает МП на 30-50 мВ или вызывает генерацию "потенциалов действия" и увеличивает чувствительность МП к повышению концентрации КС1 в среде. Следовательно, РЬ при концентрации 2,0 мг/л уже индуцирует переход клеток из энергизированного состояния с активированными Н-насосами в деэнергизированное состояние с увеличенной проницаемостью для ионов К + и Cl".



Pages:     | 1 |   ...   | 31 | 32 || 34 | 35 |   ...   | 36 |


Similar works:

«PRINT WARNING – Printed copies of this document or part thereof should not be relied upon as a current reference document. ALWAYS refer to the electronic copy for the latest version. CHAPTER 19 PATHOLOGY TABLE OF CONTENTS PD/IB/GL NUMBER Institute of Clinical Pathology and Medical Research – Services Blood Management of Fresh Blood Components PD2012_016 Private Cord Blood Banking PD2005_394 Responsibilities of Medical Officers with Regard to Drivers IB2013_059 Blood and Urine Testing of...»

«Package leaflet: Information for the user Capecitabine SUN 500 mg film-coated tablets capecitabine Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.Keep this leaflet. You may need to read it again.If you have any further questions, ask your doctor or pharmacist.This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours. If you get any...»

«Volume 2, Issue 7 July 2014 The Wright Stuff A Word from Bob Wright Well, we’re back. After a lot of soul-searching, conversations with the Board of Directors, the Advisory Board, and staff – we all decided unanimously that the mission must continue. Whatever it takes. No money – no problem. No salaries – no problem. We will stay the course as long as we can and as long as the need still exists. And, with the phone ringing off the hook with cancer patients (of which there is no shortage...»

«The Intrinsic Foundations of Extrinsic Motivations and Goals: Towards a Unified Humanistic Theory of Wellbeing and Change Mick Cooper University of Strathclyde, Glasgow, UK Author Note Mick Cooper, Counselling Unit, University of Strathclyde. Correspondence to: Mick Cooper, Counselling Unit, School of Psychological Sciences and Health, 76 Southbrae Drive, Glasgow G13 1PP, E-mail: mick.cooper@strath.ac.uk The Intrinsic Foundations of Extrinsic Motivations and Goals: Towards a Unified Humanistic...»

«ASPHALT Asphalt is a dark brown or black substance derived from crude oil. It may be a solid, a semisolid, or a liquid and is a strong adhesive. Asphalt is often mistakenly confused with tar,” “coal tar,” or “pitch” because the appearance is similar and the substances may be used interchangeably in many industrial processes. Tar and pitch are derived from coal products which are chemically and physically different. Other names for asphalt include road tar, road binder, mineral pitch,...»

«www.bfr.bund.de Melons: Health Hazard through Contamination with Pathogenic Bacteria BfR opinion 021/2013, 09 August 2013 Melons can come into contact with bacteria, viruses or parasites at any stage of the food supply chain from production and transport to preparation in private households. Pathogens can be transferred from the skin to the flesh of the fruit when the melons are cut. At warm temperatures, in particular Salmonella, Listeria and EHEC can easily multiply on the flesh which is low...»

«Regulation of the Practice of Traditional Medicine in China, India, and Malaysia By Cheng Soon Goh Submitted in accordance with the requirement for the degree of PhD The University of Leeds School of Law March, 2012 The Candidate confirms that the work submitted is her own and that appropriate credit has been given where reference has been made to the work of others. This copy has been supplied on the understanding that it is copyright material and that no quotation from the thesis may be...»

«STSA 60th ANNUAL MEETING OCTOBER 30 – NOVEMBER 2, 2013 H YAT T R EG E N C Y R E S O R T AND SPA AT GAINEY RANCH SPECIAL THANKS SPECIAL THANKS TO STSA 60TH ANNUAL MEETING CORPORATE SUPPORTERS PLATINUM St. Jude Medical, Inc. GOLD Medtronic, Inc. Terumo Cardiovascular Systems SILVER Thoratec Corporation Olympus Corporation of the Americas STSA 60th Annual Meeting 1 FUTURE MEETINGS November 5-8, 2014 JW Marriott Starr Pass Resort Tucson, AZ November 4-7, 2015 Disney’s Yacht & Beach Club Resort...»

«Oxford UnitedHealthcare® Oxford Clinical Policy OBSTRUCTIVE SLEEP APNEA TREATMENT Policy Number: OUTPATIENT 020.32 T2 Effective Date: October 1, 2016 Table of Contents Page Related Policies INSTRUCTIONS FOR USE CONDITIONS OF COVERAGE BENEFIT CONSIDERATIONS COVERAGE RATIONALE DEFINITIONS APPLICABLE CODES  Orthognathic (Jaw) Surgery DESCRIPTION OF SERVICES CLINICAL EVIDENCE U.S. FOOD AND DRUG ADMINISTRATION REFERENCES POLICY HISTORY/REVISION INFORMATION. 25 INSTRUCTIONS FOR USE This Clinical...»

«Prim Care Clin Office Pract 34 (2007) 761–789 Polycystic Ovary Syndrome: A Common Reproductive and Metabolic Disorder Necessitating Early Recognition and Treatment Walter Futterweit, MD, FACP, FACE Division of Endocrinology, Mount Sinai School of Medicine, One Gustave Levy Place, Mount Sinai Medical Center, Atran Building, 4th floor, New York, NY 10029, USA Polycystic ovary syndrome (PCOS), a heterogeneous syndrome, is the most frequently encountered endocrine disturbance in women of...»

«University of Surrey Microarray Experiment Guidelines Version 1 (Feb 2008) Copyright: © 2008 E. Laing, G. Bucca, C. P. Smith. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: This material is based on work supported by the European Commission FP6 ActinoGEN programme grant no. 005224 and the BBSRC....»

«WHO-EM/HRH/632/E Report on the Intercountry meeting on strengthening medical education in the Eastern Mediterranean Region Cairo, Egypt 27–29 November 2014 WHO-EM/HRH/632/E Report on the Intercountry meeting on strengthening medical education in the Eastern Mediterranean Region Cairo, Egypt 27–29 November 2014 © World Health Organization 2015 All rights reserved. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion...»





 
<<  HOME   |    CONTACTS
2016 www.dissertation.xlibx.info - Dissertations, online materials

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.