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1.
Int J Parasitol Parasites Wildl ; 24: 100929, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38601058

RESUMEN

Our knowledge of parasites in wildlife remains limited, primarily due to restricted access to samples, especially of parasites from protected species. This present study contributes to the comprehension of the enigmatic world of helminths of African wild mammals and cestode biodiversity by combining both molecular and morphological analysis. Cestode samples were opportunistically collected from 77 individual definitive hosts in South Africa, Namibia and Ethiopia, encompassing 15 different species of wild African carnivores and additionally domestic cats. The analysis revealed 32 different cyclophyllidean species of which 21 (65.6 %) represent previously unknown genetic entities. They belong to the families Mesocestoididae, Hymenolepididae, Dipylidiidae and Taeniidae. Here we cover the non-taeniid cestodes, while the taeniids will be addressed in a separate publication. Three of the non-taeniid species uncovered in this study could be assigned to the genus Mesocestoides and were isolated from servals and domestic cats. The white-tailed mongoose was found to be a suitable host for a species belonging to the Hymenolepididae, which was identified as Pseudandrya cf. mkuzii. Both feline and canine genotypes of Dipylidium caninum were detected in domestic cats, the canine genotype also in an African wolf. In addition to these, a novel species of Dipylidium was discovered in an aardwolf. Lastly, four distinct species of Joyeuxiella were found in this study, revealing a cryptic species complex and emphasizing the need for a taxonomic reassessment of this genus. Despite the limited scope of our study in terms of geography and sample size, the results highlight that biodiversity of cestodes in African wild mammals is grossly under-researched and follow-up studies are urgently required, in particular linking morphology to gene sequences.

2.
Helminthologia ; 60(2): 166-174, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37745224

RESUMEN

A study of the parasite fauna of feral cats in Dubai revealed the presence of two Joyeuxiella species, J. pasqualei (Diamare, 1893) and J. fuhrmanni (Baer, 1924). While the wide distribution of J. pasqualei includes countries of the Middle East, Africa, Asia and Europe, J. fuhrmanni was previously reported from felid hosts from southern Africa and has not been found in other cat parasite surveys in the Middle East, except from Dubai. The availability of historical references, however, raised doubts about the correctness of the allocation of the small Joyeuxiella sp. from Dubai cats to J. fuhrmanni and for this reason, a reexamination of stored material in the parasite collection of the Central Veterinary Research Laboratory in Dubai was carried out. A total of 40 specimens of the small Joyeuxiella sp. with a strobila length between 30 and 60 mm and consisting of 52 to 85 segments obtained from domestic cats and formerly allocated to J. fuhrmanni were studied. In complete specimens, 10 - 13 rows of rostellar hooks were counted. Mature segments were wider than long, round testes were concentrated posterior to coiled vasa deferentia and did not reach the anterior rim of the proglottids. Narrow cirri reached up to 520 µm in length. Gravid segments were longer than wide and egg capsules were restricted to the space between longitudinal excretory vessels. The examination revealed that the morphology of these cestodes matched the main characteristics of J. fuhrmanni. However, the little known cestode, J. gervaisi (Setti, 1895), that had been described from Genetta abyssinica imported from Eritrea 29 years earlier and was declared a species inquirenda met the same main morphological criteria. In this paper, the status of J. gervaisi as a valid species was resurrected and J. fuhrmanni was declared a junior synonym.

3.
Anim Cogn ; 26(4): 1353-1368, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37219737

RESUMEN

Comparing oneself to others is a key process in humans that allows individuals to gauge their performances and abilities and thus develop and calibrate their self-image. Little is known about its evolutionary foundations. A key feature of social comparison is the sensitivity to other individuals' performance. Recent studies on primates produced equivocal results, leading us to distinguish between a 'strong' variant of the social comparison hypothesis formulated for humans and a 'weak' variant found in non-human primates that would comprise some elements of human social comparison. Here, we focus on corvids that are distantly related to primates and renowned for their socio-cognitive skills. We were interested in whether crows' task performances were influenced (i) by the presence of a conspecific co-actor performing the same discrimination task and (ii) by the simulated acoustic cues of a putative co-actor performing better or worse than themselves. Crows reached a learning criterion quicker when tested simultaneously as compared to when tested alone, indicating a facilitating effect of social context. The performance of a putative co-actor influenced their performance: crows were better at discriminating familiar images when their co-actor was better than they were. Standard extremity (how pronounced the difference was between the performance of the subject and that of the co-actor), and category membership (affiliation status and sex), of the putative co-actors had no effect on their performance. Our findings are in line with the 'weak' variant of social comparison and indicate that elements of human social comparison can be found outside of primates.


Asunto(s)
Cuervos , Humanos , Animales , Comparación Social , Señales (Psicología) , Evolución Biológica , Primates
4.
J Helminthol ; 96: e3, 2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-34991740

RESUMEN

At a routine health check of a female peregrine falcon, 23 trematodes preliminary identified as Prosthogonimus sp. were removed from the bursa of Fabricius. Based on morphological and molecular examination, a new species, Prosthogonimus falconis, was described. The pear-shaped flukes were 4.3-6.9 mm long, with greatest width posterior to testes. Tegumental spines measuring between 17 and 21 µm long covered the whole body. Length and width ratio of oral to ventral suckers were 1:1.3. Extracaecal, multifollicular vitelline glands commenced prior to acetabulum and terminated posterior to testes. Eggs in the distal uterus measured 21 × 12 µm. Molecular analysis of internal transcribed spacer 2, cytochrome c oxidase subunit 1 and NADH dehydrogenase subunit 1 gene regions revealed that the new species described here is phylogenetically closest to Prosthogonimus cuneatus and Prosthogonimus pellucidus clusters.


Asunto(s)
Falconiformes , Trematodos , Animales , Aves , Femenino , Trematodos/genética , Emiratos Árabes Unidos
6.
Nat Commun ; 11(1): 5978, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33293507

RESUMEN

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales/estadística & datos numéricos , Política Ambiental , Bosques , África Central , Canadá , Cambio Climático , Conservación de los Recursos Naturales/legislación & jurisprudencia , Nueva Guinea , Federación de Rusia
7.
Helminthologia ; 56(2): 151-156, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31662686

RESUMEN

During a survey on tapeworm larval stages in Artemia franciscana from an artificial pond in Dubai, United Arab Emirates, a high prevalence of Eurycestus avoceti-like cysticercoids was established. Adult male and female crustaceans showed a prevalence of 61.9 and 62.7 %, respectively. The intensity ranged from one to four and one to three cyst, respectively. Out of 215 examined cysticercoids, 207 specimens had morphological features matching with E. avoceti. The flaky structure of the surrounding capsule, the elongated shape of the cysticercoid and the larger number of hooklets on the suckers suggest that the eight further larval cestodes belonged to another species of the genus Eurycestus.

8.
Vet Parasitol ; 262: 75-83, 2018 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-30389015

RESUMEN

Domesticated Old World camels (Camelus dromedarius and C. bactrianus) are important for the economy of several countries in Asia, Africa, and the Arabian Peninsula, and coccidiosis is important as a cause of mortality in juvenile camels. There is confusion concerning the species of coccidian parasites in camels and their life cycles. The objective of the present paper is to review biology of the Eimeria and Cystoisospora species in camels. The following conclusions were drawn. Although five species of Eimeria; E. cameli, E. rajasthani, E. dromedarii, E. bactriani, and E. pellerdyi were named from camels, only E. cameli, E. rajasthani, E. dromedarii have been consistently found in numerous surveys and they are morphologically distinct. We consider E. pellerdyi and E. bacterini as species enquirende/ not valid. E. cameli oocysts are distinctive, dark brown and up to 108 µm long. Its gametogonic stages and oocysts are present in the lamina propria of small intestines; only sexual stages have been confirmed. The remaining species of Eimeria (E. rajasthani and E. dromedarii) in camels are <40 µm long and their endogenous stages are unknown. There is one valid species of Cystoisospora, C. orlovi in camels and is associated with severe disease in young camels, both pastoral and stall fed camels. Camels as young as nine days old can develop severe diarrhea and can die before oocysts are detected in feces. Lesions and endogenous stages are confined to the large intestine. The main lesion is hemorrhagic, diphtheroid to hemorrhagic colitis-associated with sexual stages; asexual stages are unknown. Oocysts are rarely excreted by adult camels, and in low numbers. Therefore, infection in very young camels remains unexplained.


Asunto(s)
Camelus/parasitología , Coccidiosis/veterinaria , Eimeria/aislamiento & purificación , Sarcocystidae/aislamiento & purificación , África/epidemiología , Animales , Arabia/epidemiología , Asia/epidemiología , Coccidiosis/epidemiología , Coccidiosis/parasitología , Coccidiosis/patología , Eimeria/citología , Heces/parasitología , Intestinos/parasitología , Intestinos/patología , Oocistos , Sarcocystidae/citología
9.
J Helminthol ; 94: e5, 2018 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-30369336

RESUMEN

A total of 1840 brine shrimps (Artemia franciscana) were examined for cestode larvae at monthly intervals between November 2015 and June 2016. Of these, 663 (36.03%) specimens were infected with cysticercoids of seven cestode species in numbers between one and sixteen. During the first four months of examination, the percentage of infected shrimps was low but rose significantly with increasing temperatures in March, reaching maximum values in May. Flamingolepis liguloides and Flamingolepis flamingo showed the highest prevalence overall, at 25.3 and 10.7%, respectively. The intensity of infection was 1-10 and 1-4 cysticercoids, respectively. Eurycestus avoceti, Wardium stellorae, Gynandrotaenia stammeri, Anomotaenia tringae and Confluaria podicipina occurred at lower prevalence of 4.5, 3.2, 1.7, 0.3 and 0.05%, respectively. Up to four species were detected in one host.


Asunto(s)
Artemia/parasitología , Cestodos/aislamiento & purificación , Lagos/parasitología , Mariscos/parasitología , Animales , Cestodos/clasificación , Larva/clasificación , Emiratos Árabes Unidos
10.
Chaos ; 28(4): 045113, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31906625

RESUMEN

The dynamical behavior of an array of microelectrodes is investigated under controlled current conditions during CO electrooxidation, a bistable electrochemical reaction with an S-shaped negative differential resistance (S-NDR) current-potential curve. Under these conditions, the total current constitutes a globally conserved quantity, thus coupling all microelectrodes globally. Upon increasing the total current, the microelectrodes activate one by one, with a single microelectrode being on its intermediate S-NDR current branch and the other ones being either on their passive or their active branches. When a few coupled microelectrodes are activated, the electrochemical system exhibits spontaneous potential oscillations. Mathematical analysis shows that oscillations arise already in a two group approximation of the dynamics, the two groups consisting of 1 electrode and n - 1 electrodes with n ≥ 3, respectively, with each group being described by a single evolution equation. In this minimal representation, oscillations occur when the single electrode is on the intermediate branch and the larger group is on the active branch.

11.
Int J Food Microbiol ; 253: 54-58, 2017 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-28482282

RESUMEN

Vibrio vulnificus (Vv) and V. parahaemolyticus (Vp) illnesses are typically acquired through the consumption of raw molluscan shellfish, particularly oysters. As Vibrio spp. are naturally-occurring bacteria, one means of mitigation of illness is achieved by limiting post-harvest growth. In this study, effects of ambient air storage, refrigeration, and icing of oysters on Vibrio spp. abundances were examined at two sites in Alabama (AL) [Dog River (DR) and Cedar Point (CP)] and one site in Delaware Bay, New Jersey (NJ). As the United States shellfish program recommendations include testing for total these organisms and gene targets, Vv and total (tlh) and pathogenic (tdh+ and trh+) Vp were enumerated from samples using MPN-real-time-PCR approaches. Mean Vv and Vp abundances in oysters from AL-DR were lowest in immediately iced samples (2.3 and -0.1 log MPN/g, respectively) and highest in the 5h ambient then refrigerated samples (3.4 and 0.5 log MPN/g, respectively). Similarly, in AL-CP Vv and Vp mean levels in oysters were lowest in immediately iced samples (3.6 and 1.2 log MPN/g, respectively) and highest in 5h ambient then refrigerated samples (5.1 and 3.2 log MPN/g, respectively). Mean levels of pathogenic Vp from AL sites were frequently below the limit of detection (<0.3 MPN/g). In NJ, Vv and Vp mean abundances in oysters were highest in samples which were held for 7h in the shade (5.3 and 4.8 log MPN/g, respectively). Mean pathogenic Vp levels in oysters at initial harvest were also highest in oysters 7h in the shade (2.1 and 2.2 log MPN/g for tdh+ and trh+ Vp). Regardless of sampling location, Vibrio spp. levels were generally significantly (p<0.05) greater in oysters exposed to 5h of air storage compared to the initially harvested samples. In addition, the data demonstrated that the use of layered ice resulted in lower Vibrio spp. levels in oysters, compared to those that were refrigerated post-harvest. These results suggest vibriosis risk can be mitigated by shorter storage times and more rapid cooling of oysters, providing data regulatory authorities can use to evaluate Vibrio spp. control plans.


Asunto(s)
Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/prevención & control , Ostreidae/microbiología , Mariscos/microbiología , Vibriosis/prevención & control , Vibrio parahaemolyticus/crecimiento & desarrollo , Vibrio vulnificus/crecimiento & desarrollo , Animales , Frío , Recuento de Colonia Microbiana , Perros , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Refrigeración , Estados Unidos , Vibriosis/microbiología , Vibrio parahaemolyticus/genética , Vibrio vulnificus/genética
12.
Gene Ther ; 24(9): 562-571, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28440796

RESUMEN

Over the last two decades, important contributions were made at national, European and international levels to foster collaboration into rare diseases research. The European Union (EU) has put much effort into funding rare diseases research, encouraging national funding organizations to collaborate together in the E-Rare program, setting up European Reference Networks for rare diseases and complex conditions, and initiating the International Rare Diseases Research Consortium (IRDiRC) together with the National Institutes of Health in the USA. Co-ordination of the activities of funding agencies, academic researchers, companies, regulatory bodies, and patient advocacy organizations and partnerships with, for example, the European Research Infrastructures maximizes the collective impact of global investments in rare diseases research. This contributes to accelerating progress, for example, in faster diagnosis through enhanced discovery of causative genes, better understanding of natural history of rare diseases through creation of common registries and databases and boosting of innovative therapeutic approaches. Several examples of funded pre-clinical and clinical gene therapy projects show that integration of multinational and multidisciplinary expertize generates new knowledge and can result in multicentre gene therapy trials. International collaboration in rare diseases research is key to improve the life of people living with a rare disease.


Asunto(s)
Investigación Biomédica/organización & administración , Cooperación Internacional , Enfermedades Raras/terapia , Investigación Biomédica/economía , Unión Europea , Humanos , Enfermedades Raras/diagnóstico
13.
Appl Environ Microbiol ; 82(15): 4517-4522, 2016 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-27208133

RESUMEN

UNLABELLED: Vibrio parahaemolyticus and Vibrio vulnificus can grow rapidly in shellfish subjected to ambient air conditions, such as during intertidal exposure. In this study, levels of total and pathogenic (tdh(+) and/or trh(+)) V. parahaemolyticus and total V. vulnificus were determined in oysters collected from two study locations where intertidal harvest practices are common. Samples were collected directly off intertidal flats, after exposure (ambient air [Washington State] or refrigerated [New Jersey]), and after reimmersion by natural tidal cycles. Samples were processed using a most-probable-number (MPN) real-time PCR method for total and pathogenic V. parahaemolyticus or V. vulnificus In Washington State, the mean levels of V. parahaemolyticus increased 1.38 log MPN/g following intertidal exposure and dropped 1.41 log MPN/g after reimmersion for 1 day, but the levels were dependent upon the container type utilized. Pathogenic V. parahaemolyticus levels followed a similar trend. However, V. vulnificus levels increased 0.10 log MPN/g during intertidal exposure in Washington but decreased by >1 log MPN/g after reimmersion. In New Jersey, initial levels of all vibrios studied were not significantly altered during the refrigerated sorting and containerizing process. However, there was an increase in levels after the first day of reimmersion by 0.79, 0.72, 0.92, and 0.71 log MPN/g for total, tdh(+) and trh(+) V. parahaemolyticus, and V. vulnificus, respectively. The levels of all targets decreased to those similar to background after a second day of reimmersion. These data indicate that the intertidal harvest and handling practices for oysters that were studied in Washington and New Jersey do not increase the risk of illness from V. parahaemolyticus or V. vulnificus IMPORTANCE: Vibrio parahaemolyticus and Vibrio vulnificus are the leading causes of seafood-associated infectious morbidity and mortality in the United States. Vibrio spp. can grow rapidly in shellfish subjected to ambient air conditions, such as during periods of intertidal exposure. When oysters are submersed with the incoming tide, the vibrios can be purged. However, data on the rates of increase and purging during intertidal harvest are scarce, which limits the accuracy of risk assessments. The objective of this study was to help fill these data gaps by determining the levels of total and pathogenic (tdh(+) and/or trh(+)) V. parahaemolyticus and V. vulnificus in oysters from two locations where intertidal harvest practices are common, using the current industry practices. The data generated provide insight into the responses of Vibrio spp. to relevant practices of the industry and public health, which can be incorporated into risk management decisions.


Asunto(s)
Ostreidae/microbiología , Mariscos/microbiología , Vibrio parahaemolyticus/aislamiento & purificación , Vibrio vulnificus/aislamiento & purificación , Animales , Contaminación de Alimentos/análisis , Manipulación de Alimentos , Vibrio parahaemolyticus/clasificación , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/crecimiento & desarrollo , Vibrio vulnificus/clasificación , Vibrio vulnificus/genética , Vibrio vulnificus/crecimiento & desarrollo
14.
Phys Rev Lett ; 115(2): 026404, 2015 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-26207489

RESUMEN

We report on the energy- and momentum-resolved optical response of black phosphorus (BP) in its bulk form. Along the armchair direction of the puckered layers, we find a highly dispersive mode that is strongly suppressed in the perpendicular (zigzag) direction. This mode emerges out of the single-particle continuum for finite values of momentum and is therefore interpreted as an exciton. We argue that this exciton, which has already been predicted theoretically for phosphorene-the monolayer form of BP-can be detected by conventional optical spectroscopy in the two-dimensional case and might pave the way for optoelectronic applications of this emerging material.

15.
Lithos ; 227: 161-178, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-31007282

RESUMEN

Permian metapegmatite muscovite from the Upper-Austroalpine Matsch Unit in Southern Tyrol (Italy) was investigated regarding its Rb/Sr and compositional retentivity during Cretaceous Upper-greenschist facies deformation. The data imply that microstructurally relic Permian magmatic muscovite largely maintained its major and trace element compositions during deformation, whereas the Rb/Sr geochronometer is strongly affected by a net loss of Sr. Lower Sr concentrations of muscovite correlate with higher 87Rb/86Sr and 87Sr/86Sr ratios. In most samples, the muscovite grain size- and magnetic-fractions with the lowest 87Rb/86Sr and 87Sr/86Sr ratios preserve a Permo-Triassic muscovite-whole rock Rb/Sr apparent age interpreted as to reflect formation during or cooling after pegmatite emplacement. Contrastingly, muscovite fractions with higher 87Rb/86Sr and 87Sr/86Sr ratios are arranged along a roughly linear array with a positive correlation of the 87Rb/86Sr and 87Sr/86Sr ratios in the 87Rb/86Sr vs 87Sr/86Sr space. They yield successively lower muscovite-whole rock Rb/Sr apparent ages. We explain the variations in the Rb/Sr isotopic character of microstructurally relic muscovite by a, presumably deformation-related, loss of Sr during the Cretaceous event. Contemporaneously, only very limited amounts of isotopically different Sr from the matrix reservoir might possibly have entered the muscovite. Consequently, the Rb/Sr of the relic muscovite is affected by a net loss of Sr. The results imply that at temperatures of < 500 °C, deformation is supposed to be the predominant factor in controlling the Rb/Sr geochronometer of relic muscovite, by significantly reducing the characteristic length scale for volume diffusion. However, variations of the major and trace element compositions within Permian relic muscovite are interpreted to rather reflect primary compositional instead of deformation-related variations.

16.
Clin Exp Immunol ; 179(2): 161-72, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25351931

RESUMEN

One would assume that the anti-inflammatory activity of α1-anti-trypsin (AAT) is the result of inhibiting neutrophil enzymes. However, AAT exhibits tolerogenic activities that are difficult to explain by serine-protease inhibition or by reduced inflammatory parameters. Targets outside the serine-protease family have been identified, supporting the notion that elastase inhibition, the only functional factory release criteria for clinical-grade AAT, is over-emphasized. Non-obvious developments in the understanding of AAT biology disqualify it from being a straightforward anti-inflammatory agent: AAT does not block dendritic cell activities, nor does it promote viral and tumour susceptibilities, stunt B lymphocyte responses or render treated patients susceptible to infections; accordingly, outcomes of elevated AAT do not overlap those attained by immunosuppression. Aside from the acute-phase response, AAT rises during the third trimester of pregnancy and also in advanced age. At the molecular level, AAT docks onto cholesterol-rich lipid-rafts and circulating lipid particles, directly binds interleukin (IL)-8, ADAM metallopeptidase domain 17 (ADAM17) and danger-associated molecular pattern (DAMP) molecules, and its activity is lost to smoke, high glucose levels and bacterial proteases, introducing a novel entity - 'relative AAT deficiency'. Unlike immunosuppression, AAT appears to help the immune system to distinguish between desired responses against authentic threats, and unwanted responses fuelled by a positive feedback loop perpetuated by, and at the expense of, inflamed injured innocent bystander cells. With a remarkable clinical safety record, AAT treatment is currently tested in clinical trials for its potential benefit in a variety of categorically distinct pathologies that share at least one common driving force: cell injury.


Asunto(s)
Inmunidad Adaptativa , Linfocitos B/inmunología , Células Dendríticas/inmunología , Inmunidad Innata , Terapia de Inmunosupresión/métodos , alfa 1-Antitripsina/uso terapéutico , Proteínas ADAM/antagonistas & inhibidores , Proteínas ADAM/inmunología , Proteína ADAM17 , Linfocitos B/patología , Células Dendríticas/patología , Femenino , Humanos , Tolerancia Inmunológica/efectos de los fármacos , Embarazo , alfa 1-Antitripsina/inmunología
17.
Faraday Discuss ; 170: 121-35, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25406482

RESUMEN

The response of the structure of the M-type barium hexaferrite (BaFe12O19) to mechanical action through high-energy milling and its impact on the magnetic behaviour of the ferrite are investigated. Due to the ability of the (57)Fe Mössbauer spectroscopic technique to probe the environment of the Fe nuclei, a valuable insight on a local atomic scale into the mechanically induced changes in the hexagonal structure of the material is obtained. It is revealed that the milling of BaFe12O19 results in the deformation of its constituent polyhedra (FeO6 octahedra, FeO4 tetrahedra and FeO5 triangular bi-pyramids) as well as in the mechanically triggered transition of the Fe(3+) cations from the regular 12k octahedral sites into the interstitial positions provided by the magnetoplumbite structure. The response of the hexaferrite to the mechanical treatment is found to be accompanied by the formation of a non-uniform nanostructure consisting of an ordered crystallite surrounded/separated by a structurally disordered surface shell/interface region. The distorted polyhedra and the non-equilibrium cation distribution are found to be confined to the amorphous near-surface layers of the ferrite nanoparticles with the thickness extending up to about 2 nm. The information on the mechanically induced short-range structural disorder in BaFe12O19 is complemented by an investigation of its magnetic behaviour on a macroscopic scale. It is demonstrated that the milled ferrite nanoparticles exhibit a pure superparamagnetism at room temperature. As a consequence of the far-from-equilibrium structural disorder in the surface shell of the nanoparticles, the mechanically treated BaFe12O19 exhibits a reduced magnetization and an enhanced coercivity.

18.
J Helminthol ; 88(4): 499-505, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23827046

RESUMEN

Physocephalus dromedarii stat. nov. was found in the abomasum of two adult female dromedaries originating from a farm in Dubai. Previously, this nematode has been misidentified as a subspecies of Ph. sexalatus but morphological differences are striking enough for it to be upgraded to a species. Physocephalus dromedarii is larger than Ph. sexalatus and has longer spicules. There are 20-22 oblique crests at the ventral surface between the caudal alae of the male compared to 7-8 in the case of Ph. sexalatus. The most significant differences are the presence of two pairs of papillae between cloaca and postcloacal plate of the male and the existence of a swelling in the second half of the female body formed by loops of both uterine horns.


Asunto(s)
Abomaso/parasitología , Camelus , Nematodos/clasificación , Nematodos/ultraestructura , Infecciones por Nematodos/veterinaria , Gastropatías/veterinaria , Animales , Femenino , Masculino , Infecciones por Nematodos/parasitología , Especificidad de la Especie , Gastropatías/parasitología , Emiratos Árabes Unidos/epidemiología
19.
Environ Int ; 61: 64-72, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24103347

RESUMEN

Phthalates have been used for decades in large quantities, leading to the ubiquitous exposure of the population. In an investigation of 63 German daycare centers, indoor air and dust samples were analyzed for the presence of 10 phthalate diesters. Moreover, 10 primary and secondary phthalate metabolites were quantified in urine samples from 663 children attending these facilities. In addition, the urine specimens of 150 children were collected after the weekend and before they went to daycare centers. Di-isobutyl phthalate (DiBP), dibutyl phthalate (DnBP), and di-2-ethylhexyl phthalate (DEHP) were found in the indoor air, with median values of 468, 227, and 194ng/m(3), respectively. In the dust, median values of 888mg/kg for DEHP and 302mg/kg for di-isononyl phthalate (DiNP) were observed. DnBP and DiBP were together responsible for 55% of the total phthalate concentration in the indoor air, whereas DEHP and DiNP were responsible for 70% and 24% of the total phthalate concentration in the dust. Median concentrations in the urine specimens were 44.7µg/l for the DiBP monoester, 32.4µg/l for the DnBP monoester, and 16.5µg/l and 17.9µg/l for the two secondary DEHP metabolites. For some phthalates, we observed significant correlations between their concentrations in the indoor air and dust and their corresponding metabolites in the urine specimens using bivariate analyses. In multivariate analyses, the concentrations in dust were not associated with urinary metabolite excretion after controlling for the concentrations in the indoor air. The total daily "high" intake levels based on the 95th percentiles calculated from the biomonitoring data were 14.1µg/kg b.w. for DiNP and 11.9µg/kg b.w. for DEHP. Compared with tolerable daily intake (TDI) values, our "high" intake was 62% of the TDI value for DiBP, 49% for DnBP, 24% for DEHP, and 9% for DiNP. For DiBP, the total daily intake exceeded the TDI value for 2.4% of the individuals. Using a cumulative risk-assessment approach for the sum of DEHP, DnBP, and DiBP, 20% of the children had concentrations exceeding the hazard index of one. Therefore, a further reduction of the phthalate exposure of children is needed.


Asunto(s)
Aire/análisis , Guarderías Infantiles/estadística & datos numéricos , Polvo/análisis , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Ácidos Ftálicos/análisis , Niño , Preescolar , Contaminantes Ambientales/metabolismo , Contaminantes Ambientales/orina , Femenino , Alemania , Humanos , Lactante , Masculino , Ácidos Ftálicos/química , Ácidos Ftálicos/metabolismo , Ácidos Ftálicos/orina
20.
Arq. bras. med. vet. zootec ; 65(3): 826-832, June 2013. graf, tab
Artículo en Portugués | LILACS | ID: lil-679119

RESUMEN

Avaliou-se o efeito da suplementação com óleo de linhaça na dieta, com ou sem injeção de selenito de sódio, sobre o perfil de ácidos graxos e sobre a estabilidade oxidativa do leite de vacas leiteiras. Catorze vacas foram distribuídas em três tratamentos: as do grupo 1, que receberam diariamente 400mL de óleo de linhaça (LIN); as do grupo 2, 400mL de óleo de linhaça + 0,2mg/kg de selenito de sódio IM (LINSe); e as do grupo 3 (controle), que não foram tratadas (C). O óleo foi fornecido diariamente após 15 dias da aplicação única de selenito de sódio, e o experimento teve duração de quatro semanas. Os animais suplementados com o óleo de linhaça produziram leite com altas porcentagens de ácido linoleico conjugado (CLA) e de ômega 3, contudo mais suscetível à oxidação. A aplicação injetável de selenito de sódio mostrou-se eficaz ao impedir a oxidação prematura do leite. Concluiu-se que a inclusão do óleo de linhaça na dieta de vacas leiteiras resulta em aumento do CLA, do ômega 3 e, consequentemente, da oxidação do leite, necessitando, assim do uso de substâncias antioxidantes ou promotores antioxidantes, como o selenito de sódio injetável.


The aim of the present study was to evaluate the effect of dietary linseed oil supplementation with or without injectable sodium selenite on the fatty acid profile and oxidative stability of milk from dairy cows. Fourteen cows were allocated into four treatment groups: Group 1 which received 400mL of linseed oil daily (LIN); Group 2, 400mL of linseed oil + 0,2mg/BW sodium selenite IM (LINSe); Group 3, untreated controls (C). The oil was supplied daily after 15 days of a single application of sodium selenite and during 4 weeks. Animals supplemented with linseed oil produced milk with higher levels of conjugated linoleic acid (CLA) and omega 3, but were also more susceptible to oxidation. The application of sodium selenite was effective to prevent premature oxidation of milk. We concluded that the supplementation of a cow's diet with linseed oil promoted increased CLA and omega 3 in milk, which in turn becomes more susceptible to oxidation, requiring the use of antioxidants or promoters of antioxidant activity such as injectable sodium selenite.


Asunto(s)
Animales , Bovinos , Dieta/métodos , Ácidos Grasos , Leche , Aceite de Linaza/análisis , Bovinos/clasificación
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