18 research outputs found
Photocatalytic removal of aldrin and dieldrin using graphene oxide and TiO<sub>2</sub>-doped CuFe<sub>2</sub>O<sub>4</sub>
No full textBACKGROUND Conventional treatment processes and existing photocatalysts have proven insufficient in efficiently removing aldrin and dieldrin. Consequently, this study aimed to investigate the removal of aldrin and dieldrin from surface water using a titanium dioxide/graphene oxide/copper ferrite (TiO2/GO/CuFe2O4) nanocomposite. RESULTS The highest photodegradation efficiencies for aldrin (100%) and dieldrin (99%) were achieved with a TiO2/GO/CuFe2O4 nanocomposite dosage of 1.3 mg L-1, at a sunlight intensity of 9 W m(-2) and an optimal photodegradation time of 25 min. The maximum UV absorption wavelength of the TiO2/GO/CuFe2O4 nanocomposite was observed at 365 nm. The quantum yield of the nanocomposite was recorded as 2.69 x 10(2) mol einstein-1, and its bandgap energy was determined to be 3.31 eV. The first-order kinetic rate constants for aldrin and dieldrin were calculated as 0.05 and 0.047 min(-1), respectively. X-ray diffraction analysis confirmed the crystal structure of CuFe2O4/TiO2, while Fourier transform infrared spectroscopy detected carboxylic, epoxy, carbonyl and other oxygenated groups within the TiO2/GO/CuFe2O4 nanocomposite. Scanning electron microscopy and transmission electron microscopy images revealed that CuFe2O4 was situated on the outer layer of GO. Energy-dispersive X-ray analysis identified the elemental composition of the TiO2/GO/CuFe2O4 nanocomposite as comprising GO, C, Cu, Fe, Ti and O. A reusability study demonstrated that the nanocomposite maintained excellent performance, achieving 99% removal efficiency after 79 cycles and 97% after 100 cycles. CONCLUSIONS The TiO2/GO/CuFe2O4 nanocomposite effectively removed aldrin and dieldrin from surface water. This nanocomposite holds promise for the remediation of other aquatic ecosystems, such as bays, rivers and ocean waters. (c) 2024 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI)
Liver parasites and body condition in relation to environmental contaminants in caribou (Rangifer tarandus) from Labrador, Canada
No full textOver the last several decades, elders and hunters of the Innu Nation in Labrador, Canada, have expressed concerns over perceived declines in environmental health and the integrity of country food, including caribou. The primary objective of this study was to determine links between specific health parameters and contaminants found in caribou from the George River herd. Twenty-seven caribou killed by local Innu hunters between February and December 2001 were evaluated for gross and microscopic pathology, body condition, liver parasitology, and contaminant levels in kidney and fat. Overall, the sampled caribou appeared to be in adequate body condition for the time of year, and no clinically significant lesions were found. Concentrations of selenium, metals (Hg, Cd, and Pb), 20 organochlorine pesticides (HCB, a-HCH, g-HCH, aldrin, dieldrin, methoxychlor, mirex, a- and b-endosulfan, heptachlor, heptachlor epoxide, g-CHL, cis-CHL, trans-nonachlor, and o,p'- and p,p'-DDD, DDE, DDT), and 24 PCB congeners were within the ranges reported for caribou in Canada. In general, contaminant levels were relatively low, with the exception of cadmium in kidneys (geometric mean: 6.5 µg/g wet weight; range: 1.5–44.0 µg/g). Two types of liver parasites were found: the liver fluke Fascioloides magna (prevalence: 78%; geometric mean abundance: 4.2 flukes/caribou) and a tapeworm larva consistent with Taenia hydatigena (prevalence: 50%; geometric mean abundance: 0.6 larvae/caribou). Using multiple variable regression analysis, we found renal concentrations of cadmium to be positively associated, and selenium to be negatively associated, with F. magna abundance.Source type: Printhttp://proquest.umi.com/pqdweb?did=1671852081&am
Chemical characterization of a municipal landfill and its influence on the surrounding estuarine system, South Central Chile.
No full textThe spatial and temporal variations of cyclic organochlorine compounds, heavy metals, total hydrocarbons, surfactants, oil and grease, BOD, (biochemical oxygen demand), dissolved oxygen and nutrients were measured during summer and winter of 1996 from the Valdivia municipal landfill and its surrounding estuarine system. During summer it was found that solid and liquid samples usually contained higher average contents for most of chemical parameters than winter samples, with the exception of oil and grease and Pb from leachate samples. Generally, samples from the landfill showed higher levels of chemical parameters than samples from the Futa River. High levels of heptachlor (52.1 ng/g and 31.5 ng/g during summer and winter, respectively) and endosulfan sulphate (127.4 n/g and 11,5 ng/g during summer and winter, respectively) were observed in sediments from a maximum depository zone of a small river adjacent to the landfill which receives the percolated leachates. The temporal variability (summer winter) showed a significant dilution of pollutants, probably due to rainfall during winter. Estuarine benthos species, Mulinia edulis (clams) and cancer coronatus (crabs) showed low levels for most metals, except Zn in both species, Ni in clams, Cu and As in crabs. Significant levels of total BHC, 4,4'-DDE, aldrin, endrin ketone and heptachlor epoxide were observed in Mytilus chilensis (mussels).PT: J; CR: *APHA AWWA WEF, 1905, STAND METH EX WAT WA *EPA, 1986, EPA440586001 CHU LM, 1994, ENVIRON MANAGE, V18, P105 CYR F, 1987, B ENVIRON CONTAM TOX, V38, P775 DEGREGORI I, 1992, SCI TOTAL ENVIRON, V111, P201 ERNST WR, 1994, WATER POLL RES J CAN, V29, P89 GINTAUTAS PA, 1992, ENVIRON SCI TECHNOL, V26, P517 HALLBOURG RR, 1992, WATER AIR SOIL POLL, V65, P307 HARTMANN KH, 1990, WATER SCI TECHNOL, V22, P307 HELWEG A, 1994, PESTICIDE OUTLOOK, V5, P12 HUSAIN T, 1989, WATER AIR SOIL POLL, V45, P191 KEIM ML, 1999, COMMUNICATION KJELDSEN P, 1990, J CONTAM HYDROL, V6, P165 KOLTZ DM, 1996, ENV HLTH PERSPECT, V104, P1084 MARTENS R, 1976, APPL ENVIRON MICROB, V31, P853 NAVAS JM, 1998, ENVIRON SCI POLLUT R, V5, P75 NELSON P, 1996, THESIS U AUSTRAL CHI OMAN C, 1993, ENVIRON POLLUT, V80, P265 PALMAFLEMING H, 1998, BOL SOC CHIL QUIM, V43, P201 PALMAFLEMING H, 1998, BOL SOC CHIL QUIM, V43, P435 PETERSON SM, 1993, ENVIRON POLLUT, V82, P143 PINO M, 1994, ESTUAR COAST SHELF S, V38, P491 QUIROZ E, 1997, 12 JORN CHIL QUIM 12, P27 RAGLE N, 1995, WATER ENVIRON RES, V67, P238 RENNER R, 1999, ENVIRON SCI TECHNOL, V33, A62 ROBINSON HD, 1983, WATER RES, V17, P1537 ROBINSON HD, 1985, J WATER POLLUT CONTR, V57, P30 ROY WR, 1994, CONTAMINATION GROUND, P411 ZHANG Z, 1993, ANAL CHEM, V65, P1843; NR: 29; TC: 1; J9: BOL SOC CHIL QUIM; PG: 11; GA: 392APSource type: Electronic(1
Laboratory Study of the Release of Pesticide and PCB Materials to the Water Column During Dredging and Disposal Operations
No full text-Sediments, water column water, and interfacial water samples were obtained from dredged areas located in Calumet Harbor, Chicago; Green Bay near the mouth of the Fox River, Wisconsin; Mt. Hope Bay near Fall River, Massachusetts; Tabbs Bay near the Houston Ship Channel, Texas; and the Mississippi River near Memphis, Tennessee. Samples were analyzed for pesticide materials, PCB, oil and grease, total organic carbon, and silt and clay fraction. Measurable amounts of Polychlorinated biphenyls (PCB) were found in almost all samples. Of the pesticides, dieldrin and DDT compounds were the most common. Aldrin and 2,4-D esters were present in a few samples. No correlation was found between the amount of TOC, oil and grease, and silt and clay fraction, and the sediment PCB content or the interstitial water PCB content. As a result of desorption tests and settling tests using several sediment to water ratios, the transfer of soluble pesticide material to the water was found to be negligible at sediment to water ratios of 1:10 or less. Chlorinated hydrocarbon materials associated with the resuspended solids reached concentrations at or near background water column levels after settling for periods ranging from 5 to 24 hr. (Author)http://gbic.tamug.edu/request.ht
A prospective study of cancer risk among the agricultural health study farm spouses associated with personal use of organochlorine insecticides
No full textBACKGROUND: Organochlorine insecticides (OCs) have historically been used worldwide to control insects, although most have now been banned in developed countries. Evidence for an association between OC exposures and cancer predominantly comes from occupational and population based-studies among men. We evaluated the association between the use of specific OCs and cancer among the female spouses of pesticide applicators in the Agricultural Health Study. METHODS: At enrollment (1993–1997), spouses of private applicators in the cohort provided information about their own personal use of pesticides, including seven OCs (aldrin, chlordane, dieldrin, DDT, heptachlor, lindane, and toxaphene), and information on potential confounders. We used Poisson regression to estimate relative risks (RRs) and 95% confidence intervals (CIs) for cancers (n≥3 exposed cancer cases) reported to state cancer registries from enrollment through 2012 (North Carolina) and 2013 (Iowa), and the self-reported personal use OCs. RESULTS: Among 28,909 female spouses, 2,191 (7.58%) reported ever use of at least one OC, of whom 287 were diagnosed with cancer. Most cancers were not associated with OC use. Risk of glioma was increased among users of at least one OC (Nexposed=11, RR=3.52, 95%CI 1.72-7.21) and specifically among lindane users (Nexposed=3, RR=4.45, 95%CI 1.36-14.55). Multiple myeloma was associated with chlordane (Nexposed=6, RR=2.71, 95%CI 1.12-6.55). Based on 3 exposed cases each, there were also positive associations between pancreatic cancer and lindane, and ER-PR- breast cancer and dieldrin. No other associations with breast cancer were found. CONCLUSIONS: Overall, there were some associations with OC use and cancer incidence, however we were limited by the small number of exposed cancer cases. Future research should attempt to expand on these findings by assessing environmental sources of OC exposures, to fully evaluate the role of OC exposures on cancer risk in women.M.S.Includes bibliographical referencesby Lydia M. Loui
Bidrag till kännedomen om för skogen skadliga bladhorningar i Sverige.
Full text linkThis study of the Melolontha melolontha L. and M. hippocastani Fabr. is the last of the previous published monogrnphies concerning the harmful beetles of the Scarabaeidae family. 1. Phyllopertha horticola L. 1953. 2. Amphimallus solstitialis L. 1956. 3. Serica brunnea L. 1958. The author reviews the regions affected by both species of these beetles, and the research which has been carried out in several countries. The author deals in detail with the occurrence of the cockchafer, his life, and the damage he does to agriculture and forestry in Scandinavia, especially in Sweden. Historical data are given about the considerable harm done to agriculture and also about the control of the beetles; i.e. the collecting and the destroying of them. An account is given of the reduction of the beetles in Sweden as well as in Denmarlk at the beginning of this century, and the cause of this. In the sixties a rapid breeding started again in several places in southern Sweden. In order to fight the beetles, cultivated land was treated with insecticides (aldrin). Biological ways of control were also tried. The cockchafer did most damage to the forest tree nurseries. The periodic enormous multiplying of the cockchafer is limited by unfavourable weather conditions and the rationalization of agriculture and forestry
Neurotoxicidad de los deoxyesfingolipidos en un modelo in vitro de neuropatía periférica inducida por taxanos
No full textIlustracionesThe use of chemotherapeutic agents such as taxanes, paclitaxel, and docetaxel, can cause neurotoxicity leading to Taxane-Induced Peripheral Neuropathy (TIPN) side effect. Previous research showed that sphingolipid (SL) metabolism was deregulated in TIPN. Specifically, the research showed an overproduction of atypical SL called 1-deoxysphingolipids (deoxySL) as a result of taxane treatment. The deoxySL have a slower degradation compared to the canonical SL, and when produced in excess, tend to accumulate, leading to neurotoxicity.
The first goal of this research aimed at evaluating the neurotoxicity of individual deoxySL. We tested the toxicity of the individual deoxySL, in two neuroblastoma cell model, KCNR and Neuro2a by LDH cytotoxicity assay and by measuring morphological changes such as neurite swellings and cell rounding. Our results showed that 1-deoxysphinganine was the most cytotoxic of the 1-deoxysphingoid bases for both neuroblastoma cell lines, KCNR and N2a. DeoxySL treatment showed morphological changes. In differentiated N2a cells, the individual deoxySL induced neurite swellings at different time points or concentrations, suggesting that neurite swellings are likely a transient neurotoxic effect of deoxySL treatment. In KCNR neuroblastoma cells, the neurotoxic effects of deoxySL manifested in rounding of the cells’ bodies. Differences in cytotoxicity and neurite swellings were evidenced in the neurotoxic effects of the 1-deoxysphingoid bases and the 1-deoxyceramides, also in the double bond isomers 4E and 14Z 1-deoxysphingosines and 1-deoxyceramides. In addition, to test if the neurotoxic effects of deoxySL include effects on actin organization we used immunocytochemistry and live cell fluorescent imaging to visualize cellular actin architecture. Our results showed that in KCRN cells, deoxySL caused actin stress fibers disruption and re-organization to cell cortex. In primary dorsal root ganglia (DRG) neurons, neurite swellings were also evidenced, and neurite actin distribution. Additionally, we addressed the question if deoxySLs’ neurotoxicity is mediated by the sphingosine-1-phosphate receptors (S1PRs) We utilized a broader functional antagonist of S1PRs, FTY720, in combination with deoxySL to identify if there is attenuation of neuritic damage caused by deoxySL. Results for the FTY720 treatment did not show attenuation of neuritic damage due to deoxySL, suggesting that other mechanisms than S1P signaling, might interact or modulate deoxySL toxicity.
In conclusion, neurotoxicity of deoxySL resulted in cytotoxicity, and morphological changes such as neurite swellings and rounding cells, in neuroblastoma cell lines, including actin re-organization in KCNR cells and DRG neurons. S1P signaling and other mechanisms that might be implicated in deoxySL neurotoxicity must continue to be studied.El uso de agentes quimioterapéuticos como taxanos, paclitaxel y docetaxel, puede causar neurotoxicidad que conlleva a un efecto secundario de neuropatía periférica inducida por taxanos (TIPN). Investigaciones anteriores mostraron que el metabolismo de los esfingolípidos (SL) estaba desregulado en la TIPN. Esta investigación mostró una sobreproducción de SL atípico llamado 1-deoxiesfingolípidos (deoxySL) como resultado del tratamiento con taxanos. Los deoxySL tienen una degradación más lenta en comparación con los SL canónicos y, cuando se producen en exceso, tienden a acumularse, lo que lleva a la neurotoxicidad.
El primer objetivo de esta investigación consistía en evaluar la neurotoxicidad de los deoxySL individuales. Probamos la toxicidad de los deoxySL individuales, en dos modelos de células de neuroblastoma, KCNR y Neuro2a mediante el ensayo de citotoxicidad LDH y midiendo los cambios morfológicos, como las hinchazones de neuritas y el redondeo celular. Nuestros resultados mostraron que la 1-deoxiesfinganina fue la más citotóxica de las bases 1-deoxiesfingoide para ambas líneas celulares de neuroblastoma, KCNR y N2a. El tratamiento con DeoxySL mostró cambios morfológicos. En células N2a diferenciadas, los deoxySL individuales indujeron a hinchazones de neuritas en diferentes momentos o concentraciones, lo que sugiere que las hinchazones de neuritas son probablemente un efecto neurotóxico transitorio del tratamiento con deoxySL. En las células de neuroblastoma KCNR, los efectos neurotóxicos de deoxySL se manifestaron en el redondeo de los cuerpos de las células. Las diferencias en la citotoxicidad y la hinchazón de las neuritas se evidenciaron en los efectos neurotóxicos de las bases 1-deoxiesfingoide y las 1-deoxiceramidas, también en los isómeros de doble enlace 4E y 14Z 1-deoxiesfingosinas y 1-deoxiceramidas. Además, para probar si los efectos neurotóxicos de deoxySL incluyen efectos sobre la organización de actina, utilizamos inmunocitoquímica e imágenes fluorescentes de células vivas para visualizar la arquitectura de actina celular. Nuestros resultados mostraron que en las células KCRN, deoxySL provocó la disrupción y reorganización de las fibras de estrés de actina en la corteza celular. En las neuronas DRG por sus siglas en inglés (Dorsal Root Ganglia), también se evidenciaron hinchazones de neuritas y distribución de actina de neuritas. Además, abordamos la cuestión de si la neurotoxicidad de deoxySL está mediada por los receptores de esfingosina-1-fosfato (S1PR). Utilizamos un antagonista funcional más amplio de S1PR, FTY720, en combinación con los deoxySL para identificar si hay atenuación del daño neurítico causado por los deoxySL. Los resultados del tratamiento con FTY720 no mostraron atenuación del daño neurítico causado por los deoxySL, lo que sugiere que otros mecanismos, además de la señalización de S1P podrían interactuar o modular la toxicidad de los deoxySL.
En conclusión, la neurotoxicidad de los deoxySL resultó en citotoxicidad y cambios morfológicos tales como hinchazones de neuritas y células redondeadas en líneas celulares de neuroblastoma, incluida la reorganización de actina en células KCNR y neuronas DRG. La señalización de S1P y otros mecanismos que podrían estar implicados en la neurotoxicidad de los deoxySL deben continuar estudiándose.MaestríaMagister en Ciencias- BiotecnologíaÁrea curricular Biotecnologí
MEMAHAMI ETNOGRAFI PAPUA MELALUI STRATEGI PEMBELAJARAN TUR STUDI
Full text linkPenelitian yang mengkaji antara metode pembelajaran tur studi dan etnografi relatif sangat terbatas khususnya dalam konteks Indonesia. Penelitian ini mengkaji pemahaman mahasiswa terhadap etnografi Papua dan tantangan melakukan tur studi etnografi berdasarkan refleksi terhadap model pembelajaran ini. Partisipan dalam penelitian adalah mahasiswa Universitas Yapis Papua, Jayapura, yang berpartisipasi dalam program tur studi ke Museum Lokabudaya, Universitas Cenderawasih. Penelitian mengadopsi penelitian kualitatif dengan metode grounded theory. Data dikumpulkan melalui wawancara dan observasi. Analisis data dilakukan melalui proses pengkodean dengan pendekatan induktif dan dengan bantuan software NVivo (12). Hasil dari analisis data membentuk beberapa kategori di antaranya budaya dan konteks (pemahaman budaya lokal), eksplorasi budaya dan keterhubungan, serta melihat budaya dalam perspektif berbeda. Hasil penelitian juga memberi gambaran tantangan tur studi berdasarkan refleksi partisipan. Kesimpulan, partisipan menunjukkan transformasi pemahaman budaya dan nilai-nilai yang lebih luas dengan tidak hanya berfokus pada budaya dan suku yang ditampilkan di museum, tetapi juga menghubungkan dengan budaya yang dibawa dan melekat pada diri partisipan. Meskipun demikian, fungsi kontrol dalam tur studi merupakan kelemahan terbesar dan dapat memberi pengaruh terhadap hasil dan tujuan pembelajaran
A Probabilistic Data Encryption scheme (PDES)
Full text linkIn this paper the author presents a probabilistic encryption scheme that is polynomially secure and has the efficiency
of deterministic schemes. From the theoretical construction of Brands and Gill (1996), it is clear that the proof of
Pseudo randomness of the quadratic residue generator is complete if it can be shown that there exists a one-way
function under the possible assumption that it is infeasible to solve the quadratic residuacity problem provided the
factorization of the composite integer is unknow
