Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailCharacteristics of Jupiter's auroral acceleration region
Ray, Licia; Gustin, Jacques ULg; Grodent, Denis ULg

Poster (2015, June)

Jupiter’s dynamic auroral region is the signature of magnetosphere-ionosphere coupling. The magnetospheric drivers of the emission are relatively well understood, yet the high-latitude characteristics of ... [more ▼]

Jupiter’s dynamic auroral region is the signature of magnetosphere-ionosphere coupling. The magnetospheric drivers of the emission are relatively well understood, yet the high-latitude characteristics of the interaction have not been measure in-situ. Ahead of Juno’s arrival next summer, we use HST STIS observations of Jupiter’s auroral emission to infer the location of Jupiter’s auroral acceleration region and the properties of the precipitating auroral electrons. We analyze two images of Jupiter’s northern emission, determining the precipitating electron energy and incident energy flux for the main aurora, Io spot, Ganymede footprint, and flare regions. The resulting relationships between energy flux and electron precipitation energy for the main auroral emission are compared to the theoretical relationship derived by Lundin & Sandahl [1978] for a range of auroral region locations, and temperatures and densities appropriate for the jovian system. [less ▲]

Detailed reference viewed: 37 (2 ULg)
Full Text
Peer Reviewed
See detailThe Characteristics of Low-Input Grasslands
Bogdan, Anca Dorina; Pacurar, Florin; Albus, Amalia et al

in ProEnvironment (2012), 5

Several studies show that the global interest in health and human nutrition is continually growing. A continuous change includes also the food production systems. There are more and more papers that ... [more ▼]

Several studies show that the global interest in health and human nutrition is continually growing. A continuous change includes also the food production systems. There are more and more papers that connect the value of agricultural production and food production system, papers that show a particular interes on the high value of products that are produced in low input agricultural systems./ On grassland canopy, these systems have a high diversity of floristic species. At European level, this concept has been extrapolated also to the farms, being a major concern regarding the quantification of inputs, aspect pursued along this paper. [less ▲]

Detailed reference viewed: 55 (2 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of Near-Death Experiences Memories as Compared to Real and Imagined Events Memories
Thonnard, Marie ULg; Charland-Verville, Vanessa ULg; Brédart, Serge ULg et al

in PLoS ONE (2013), 8(3),

Since the dawn of time, Near-Death Experiences (NDEs) have intrigued and, nowadays, are still not fully explained. Since reports of NDEs are proposed to be imagined events, and since memories of imagined ... [more ▼]

Since the dawn of time, Near-Death Experiences (NDEs) have intrigued and, nowadays, are still not fully explained. Since reports of NDEs are proposed to be imagined events, and since memories of imagined event have, on average, fewer phenomenological characteristics than real events memories, we here compared phenomenological characteristics of NDEs reports with memories of imagined and real events. We included three groups of coma survivors (8 patients with NDE as defined by the Greyson NDE scale, 6 patients without NDE but with memory of their coma, 7 patients without memories of their coma) and a group of 18 age-matched healthy volunteers. Five types of memories were assessed using Memory Characteristics Questionnaire (MCQ – Johnson et al., 1988): target memory (NDE for NDE memory group, coma memory for coma memory group, and first childhood memory for no memory and control groups), old and recent real event memories and old and recent imagined event memories. Since NDEs are known to have high emotional content, participants were requested to choose the most emotionally salient memories for both real and imagined recent and old event memories. Results showed that, in NDE memories group, NDE memories have more characteristics than memories of imagined and real events (p<0.02). NDE memories contain more self-referential and emotional information and have better clarity than memories of coma (all p<0.02). The present study showed that NDE memories contain more characteristics than real event memories and coma memories. Thus, this suggests that they cannot be considered as imagined event memories. On the contrary, their physiological origins could lead them to be really perceived although not lived in the reality. Further work is needed to better understand this phenomenon. [less ▲]

Detailed reference viewed: 210 (18 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of Necrotoxigenic Escherichia Coli Isolated from Septicemic and Diarrheic Calves between 1958 and 1970
Van Bost, Sigrid; Babe, Marie Hélène; Jacquemin, Etienne et al

in Veterinary Microbiology (2001), 82(4), 311-20

A total of 434 Escherichia coli isolated from septicemic calves between 1958 and 1965 and 430 E. coli isolated from diarrheic calves between 1967 and 1970 were studied by colony hybridisation and PCR ... [more ▼]

A total of 434 Escherichia coli isolated from septicemic calves between 1958 and 1965 and 430 E. coli isolated from diarrheic calves between 1967 and 1970 were studied by colony hybridisation and PCR assays for the presence of the cnf1- and the cnf2-like genes. They were also studied for the presence of genes coding for putative virulence factors associated with the CNF toxins including F17-, Pap- and Sfa-fimbrial adhesins and the recently described CDT-III toxin and AfaVIII-afimbrial adhesin. Thirty (7%) of the 434 septicemic strains were positive for CNF by colony hybridisation. Twenty-six were confirmed as necrotoxigenic E. coli type 2 (NTEC2) and four as NTEC1 by PCR. Thirty-five (8%) of the 430 diarrheic strains were positive for CNF by colony hybridisation. Five of them were studied by PCR and confirmed as NTEC1. The 26 septicemic NTEC2 strains and 20 of the 35 diarrheic NTEC including three of the five NTEC1 were positive for CDT-III. All adhesins studied were present in NTEC as well as in non-NTEC. NTEC1 were mainly Pap-, Sfa- and/or Afa8-positive, whereas NTEC2 were mainly F17- and/or Afa8-positive. This study shows that necrotoxigenic E. coli with their associated adhesins and toxins were present in calves as early as 1958, but their prevalence seems to have increased since that time. [less ▲]

Detailed reference viewed: 15 (0 ULg)
Full Text
Peer Reviewed
See detailCharacteristics Of Participants To 'Start To Run' Programme. Comparison Between Maintenance And Drop Out Groups
Cloes, Marc ULg; Pétré, Benoît ULg

Conference (2012)

BACKGROUND. ‘Start to run’ is a 10 weeks programme designed to people who want to resume physical activity. AIM. This study aimed to identify initial characteristics differing among people who continue to ... [more ▼]

BACKGROUND. ‘Start to run’ is a 10 weeks programme designed to people who want to resume physical activity. AIM. This study aimed to identify initial characteristics differing among people who continue to run and those who stop. METHODS. 229 subjects attending to the first lesson (W0) of the autumn session organized in 20 communities of Wallonia (French speaking part of Belgium) fulfilled a questionnaire aiming to identify their characteristics. At W10, 180 of them answered to another questionnaire (68.5% of them achieved the programme). 12 weeks after the end of the latter (W22), 54 subjects who participated to the previous step and achieved the programme answered to a third questionnaire (71.1% were still running). FINDINGS. Few differences (p ≤ .05) were identified. At W10, MG subjects started with a lower BMI, had a better perception of their economical situation, a higher confidence to run during 10 weeks, a better perception of their health status, a lower consumption of alcohol. On the other hand, it was surprising to notice that they had lower perception of the neighbourhood’s safety, representation of physical activity’s effects on health and about its advantages. At W22, MG comprised more women. Subjects of this group had a higher consumption of vegetables and tried to decrease their fat consumption in the last 2 years. They considered themselves as physically active and motivated by expectations of others, perceived a higher family and children support and saw running as reassuring and rewarding. Nevertheless, they felt to meet more stray dogs in their environment. Most of the differences correspond to the literature. Moreover, among the subjects in the DG, almost 40% were injured meaning that they would have been active without this situation. DISCUSSION. Effective physical activity resumption seems to be linked to a general health climate without overestimation of one’s competences and expectations. Recommendations are proposed for sport instructors. [less ▲]

Detailed reference viewed: 100 (24 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of patients with AIP mutation-related prolactinomas
Camby, S; Daly, Adrian ULg; VROONEN, Laurent ULg et al

in 23rd meeting of the Belgian Endocrine Society - Abstract book (2013, October 19)

Detailed reference viewed: 19 (4 ULg)
Full Text
See detailCharacteristics of patients with pituitary gigantism : results of an international study
Rostomyan, Liliya ULg; Daly, Adrian ULg; Tichomirowa, M et al

in Endocrine abstracts - 15th European Congress of Endocrinology (2013, May)

Detailed reference viewed: 37 (4 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of peri-urban dairy herds of Bobo-Dioulasso (Burkina Faso)
Sidibe, M.; Boly, Hamidou ULg; Lakouetene, T. et al

in Tropical Animal Health and Production (2004), 36(1), 95-100

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy ... [more ▼]

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy objectives and were studied. Among these peri-urban dairy farmers, 60% were settled, 36% semi-settled, and 4% transhumant. In total, they held 4558 dairy cows, of which 32% lactated during the study. The prevalence of mastitis (55%) increased (p<0.05) with herd size. Advanced strategies for supplementary feeding and breeding were most frequent in small herds (< 30 cattle). None of the large herds ( > 60 cattle) had advanced breeding strategies. Bulls and cows were culled at younger ages in herds with better breeding strategy. Overall, this resulted in higher individual milk offtake in small herds (2.46 L/day) compared with large herds (1.25 L/day). Pure breeds were rarely used, and the presence of Bos taurus baoule naturally selected for trypanotolerance was low. The prevalence of trypanosomosis (40%) in herds dominated by Bos indicus zebu and Mere (Zebu x Baoule) is an argument for maintenance of biodiversity and selection of Baoule for milk production. [less ▲]

Detailed reference viewed: 61 (17 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of poultry production systems and cost-benefit analysis of mass vaccination campaign against HPAI in poultry production systems in Long An Province, South Vietnam
Phan Dang, Thang ULg; Peyre, Marisa; Vu Dinh, Ton et al

in Journal of Science and Development (2009), 7(English.Iss.1), 8

In 2006, the poultry population of Vietnam was about 215 million heads. However, between 2004 and 2008, the Highly Pathogenic Avian Influenza (HPAI) caused by H5N1 virus was broken in affected almost all ... [more ▼]

In 2006, the poultry population of Vietnam was about 215 million heads. However, between 2004 and 2008, the Highly Pathogenic Avian Influenza (HPAI) caused by H5N1 virus was broken in affected almost all provinces in Vietnam with millions of birds culled. This had large economical and sociological impacts. A question has been raised: how could Vietnam limit this epidemic? The research aims to identify the poultry production systems with their various constraints, including diseases and to evaluate the cost-benefit impact of a mass vaccination programme implemented from March to August 2007 at local level in Long An Province within the Mekong Delta. Two principal poultry farming systems are characterised: the commercial poultry production system (system 1) with low to moderate bio-security level, and the small-scale production system (system 2) with a low bio-security level. The scenarios of cost-benefit analysis of vaccination campaigns against HAPI caused by H5N1 virus give a good strategy for the restructure of poultry production and farmers’ incentives to vaccinate. The vaccination is more cost effective for the farmer than culling operations, with the BCR scenarios are between 31 to 78 times more. [less ▲]

Detailed reference viewed: 155 (16 ULg)
Full Text
See detailCharacteristics of Pregnancy-Associated glycoprotein (PAG) like proteins in red deer
Okuyama, MW; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg

Poster (2013, June 19)

The Pregnancy-Associated glycoproteins (PAGs) constitute an asparatic proteinase family and are divided into 2 groups; bovine PAG-1 (boPAG-1) group and boPAG-2 group. PAGs have been detected in many ... [more ▼]

The Pregnancy-Associated glycoproteins (PAGs) constitute an asparatic proteinase family and are divided into 2 groups; bovine PAG-1 (boPAG-1) group and boPAG-2 group. PAGs have been detected in many domestic ruminant species and their biochemical characteristics were reported. However, information in wild ruminant, especially in deer species is scarce. The aim of this study is to investigate the characteristics of placental protein extracted in red deer (cervus elaphus); placental proteins which belong to each type of PAG group were identified in purification steps. Fresh frozen placenta (fetal cotyledon (FC): 2,247 g, maternal cotyledon (MC): 2,255 g respectively) was used as following purification step; protein extraction, acid precipitation (pH 4.5), Ammonium sulfate precipitation (SA0-40%, SA40-80%) and anion exchange chromatography (DEAE-cellulose 0M, 0,02M, 0,04M, 0,08M, 0,16M and 0,32M NaCl). In every step, Immunoreactivity against anti-PAG antisera was checked by Radioimmunoassay with using anti-PAG-1 antiserum (AS706) and anti-boPAG-2 antiserum (AS438). After Ammonium sulfate precipitation, much higher concentrations were gained in SA40-80% step (AS706: 5.35 mg/FCkg and 6.73 mg/MCkg, AS438: 24.79 mg/FCkg and 84.6 mg/MCkg) than SA0-40% step (AS706: 0.64 mg/FCkg and 0.79 mg/MCkg, AS438: 1.3 mg/FCkg and 9.34 mg/MCkg) in both part of cotyledon. After DEAE chromatography, the highest concentrations of protein against AS438 were gained in 0.08M NaCl step (5.49 mg/FCkg and 17.8 mg/MCkg) and concentrations of protein against AS706 were almost same in 0.08M NaCl (1.01 mg/FCkg and 1.35 mg/MCkg) and 0.16M NaCl (0.93 mg/FCkg and 1.34 mg/MCkg). In many ruminants such as cattle, sheep and goat, PAGs are contained largely in fetal cotyledon and most amounts of PAGs are belonging to PAG-1 group. On the other hand, in red deer, much larger amount of PAGs was obtained from maternal cotyledon. And stronger immunoreactivity with anti-boPAG-2 antisera was detected than with anti-PAG-1 antisera. This characteristic is similar to the results which were reported in pig and dromedary. Therefore, these results suggest that PAGs in red deer have different characteristics from other ruminant species. [less ▲]

Detailed reference viewed: 71 (2 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of Saturn’s FUV airglow from limb-viewing spectra obtained with Cassini-UVIS
Gustin, Jacques ULg; Stewart, Ian; Gérard, Jean-Claude ULg et al

in Icarus: International Journal of Solar System Studies (2010), 210

This study reports the analysis of far ultraviolet (FUV) limb spectra of the airglow of Saturn in the 1150–1850 Å spectral window, obtained with the Ultraviolet Imaging Spectrograph (UVIS) onboard Cassini ... [more ▼]

This study reports the analysis of far ultraviolet (FUV) limb spectra of the airglow of Saturn in the 1150–1850 Å spectral window, obtained with the Ultraviolet Imaging Spectrograph (UVIS) onboard Cassini, spanning altitudes from 1200 to 4000 km. The FUV limb emission consists of three main contributions: (1) H Ly-a peaking at 1100 km with a brightness of 0.8 kilo-Rayleighs (kR), (2) reflected sunlight longward of 1550 Å which maximizes at 950 km with 16.5 kR and (3) H2 bands in the 1150–1650 Å bandwidth, peaking at 1050 km reaching a maximum of 3.9 kR. A vertical profile of the local H2 volume emission rate has been derived using the hydrocarbon density profiles from a model of the Saturn equatorial atmosphere. It is well matched by a Chapman function, characterized by a maximum value of 3.5 photons cm-3 s-1 in the 800–1650 Å UV bandwidth, peaking at 1020 km. Comparisons between the observed spectra and a first-order synthetic airglow H2 model in the 1150–1650 Å bandwidth show that the spectral shape of the H2 bands is accounted for by solar fluorescence and photoelectron excitation. The best fits are obtained with a combination of H2 fluorescence lines and 20 eV electron impact spectra, the latter contributing 68% of the total H2 airglow emission. [less ▲]

Detailed reference viewed: 27 (4 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of Saturn's FUV aurora observed with the Space Telescope Imaging Spectrograph
Gérard, Jean-Claude ULg; Grodent, Denis ULg; Gustin, Jacques ULg et al

in Journal of Geophysical Research. Space Physics (2004), 109

We analyze a set of 15 FUV images obtained between October 1997 and January 2001 with the Hubble Space Telescope Imaging Spectrograph (STIS), providing a good view of Saturn's south auroral oval. It is ... [more ▼]

We analyze a set of 15 FUV images obtained between October 1997 and January 2001 with the Hubble Space Telescope Imaging Spectrograph (STIS), providing a good view of Saturn's south auroral oval. It is found that the morphology and brightness distribution of the aurora are dynamical with variations occurring on time scales of hours or less. The dayside main oval lies between 70° and 80° and is generally brighter and thinner in the morning than in the afternoon sector. The afternoon sector is characterized by more diffuse emission at higher latitudes. Weak emission is also observed poleward of the main oval up to the pole. A spot of enhanced auroral precipitation, tentatively identified as the optical signature of the dayside cusp, is sometimes observed poleward of the main oval in the noon sector, especially during periods when the morning arc is not fully developed. A spiral structure of the main oval with arcs at two latitudes in the same sector is occasionally observed. The brightness of the main oval ranges from below the STIS threshold of 1 kR of H[SUB]2[/SUB] emission up to ~75 kR. The total electron precipitated power varies between 20 and 140 GW, that is, comparable to the Earth's active aurora but about two orders of magnitude less than on Jupiter. An increasing trend of the precipitated power between the 1997 and the 2000-2001 observations may be related to the rising solar activity. Six spectra of the aurora in the noon sector covering the 1200-1700 Å range are dominated by emissions of the Lyman-alpha line and H[SUB]2[/SUB] Werner and Lyman bands. Their comparison with a synthetic model of electron excited H[SUB]2[/SUB] emissions indicates the presence of a weak absorption below 1400 Å by a column of methane ranging between 7 × 10[SUP]15[/SUP] and 2 × 10[SUP]16[/SUP] cm[SUP]-2[/SUP]. The corresponding energy of the primary auroral electrons is estimated 12 +/- 3 keV, using a low-latitude model atmosphere based on Voyager occultation measurements. The main oval brightness and the characteristic electron energy are generally consistent with recent models of Saturn's aurora, which colocate the main oval with the narrow upward field-aligned current system associated with departure from plasma corotation near the open-closed field line boundary. The latitude of the bright morning arc is somewhat lower than model predictions based on the plasma flow velocity measured by Voyager in the middle magnetosphere. [less ▲]

Detailed reference viewed: 15 (3 ULg)
See detailCharacteristics of Saturn's polar atmosphere and auroral electrons derived from HST/STIS, FUSE and Cassini/UVIS spectra
Gustin, Jacques ULg; Pryor, W.; Feldman, P. et al

Poster (2008, December 01)

Ultraviolet spectra of Saturn's aurora obtained with the Hubble Space Telescope Imaging Spectrograph (STIS), the Cassini Ultraviolet Imaging Spectrograph (UVIS) and the Far Ultraviolet Spectroscopic ... [more ▼]

Ultraviolet spectra of Saturn's aurora obtained with the Hubble Space Telescope Imaging Spectrograph (STIS), the Cassini Ultraviolet Imaging Spectrograph (UVIS) and the Far Ultraviolet Spectroscopic Explorer (FUSE) have been compared to synthetic spectra of electron-excited H2 in order to derive various auroral characteristics, such as the energy of the primary precipitating electrons and the H2 temperature at the altitude of the aurora. Two physical processes have been exploited: the absorption by hydrocarbons in the FUV and H2 self-absorption in the EUV. We find energies in the range 10-18 keV, which locates Saturns's aurora between 0.1 and 0.3 μ bar. We also determined that the auroral H2 emission is characterized by a temperature of ~400K, consistent with temperatures measured in the infrared, but much higher than what is expected from equatorial atmospheric models. These new results bring valuable constraints on both polar atmospheric models and theoretical studies of the ionosphere-magnetosphere coupling. [less ▲]

Detailed reference viewed: 33 (5 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of Saturn's polar atmosphere and auroral electrons derived from HST/STIS, FUSE and Cassini/UVIS spectra
Gustin, Jacques ULg; Gérard, Jean-Claude ULg; Pryor, Wayne et al

in Icarus: International Journal of Solar System Studies (2009), 200

Ultraviolet (UV) spectra of Saturn's aurora obtained with the Hubble Space Telescope Imaging Spectrograph (STIS), the Cassini Ultraviolet Imaging Spectrograph (UVIS) and the Far Ultraviolet Spectroscopic ... [more ▼]

Ultraviolet (UV) spectra of Saturn's aurora obtained with the Hubble Space Telescope Imaging Spectrograph (STIS), the Cassini Ultraviolet Imaging Spectrograph (UVIS) and the Far Ultraviolet Spectroscopic Explorer (FUSE) have been analyzed. Comparisons between the observed spectra and synthetic models of electron-excited H[SUB]2[/SUB] have been used to determine various auroral characteristics. Far ultraviolet (FUV: 1200 1700 Å) STIS and UVIS spectra exhibit, below 1400 Å, weak absorption due to methane, with a vertical column ranging between 1.4×10[SUP][/SUP] and 1.2×10[SUP][/SUP]cm[SUP][/SUP]. Using the low-latitude Moses et al. [Moses, J.I., Bézard, B., Lellouch, E., Feuchtgruber, H., Gladstone, G.R., Allen, M., 2000. Icarus, 143, 244 298] atmospheric model of Saturn and an electron energy H[SUB]2[/SUB] column relationship, these methane columns are converted into the mean energy of the primary precipitating electrons, estimated to lie in the range 10 18 keV. This result is confirmed by the study of self-absorption with UVIS and FUSE extreme ultraviolet (EUV: 900 1200 Å) spectra. Below 1200 Å, it is seen that transitions connecting to the v[SUP][/SUP]<2 vibrational levels of the H[SUB]2[/SUB] electronic ground state are partially self-absorbed by H[SUB]2[/SUB] molecules overlying the auroral emission. Because of its low spectral resolution (Ë 5.5 Å), the UVIS EUV spectrum we analyzed does not allow us to unequivocally determine reasonable ranges of temperatures and H[SUB]2[/SUB] columns. On the other hand, the high spectral resolution (Ë 0.2 Å) of the FUSE LiF1a and LiF2a EUV spectra we examined resolve the H[SUB]2[/SUB] rotational lines and makes it possible to determine the H[SUB]2[/SUB] temperature. The modeled spectrum best fitting the FUSE LiF1a observation reveals a temperature of 500 K and self-absorption by a H[SUB]2[/SUB] vertical column of 3×10[SUP][/SUP]cm[SUP][/SUP]. When converted to energy of precipitating electrons, this H[SUB]2[/SUB] column corresponds to primary electrons of Ë 10 keV. The model that best fits the LiF2a spectrum is characterized by a temperature of 400 K and is not self-absorbed, making this segment ideal to determine the H[SUB]2[/SUB] temperature at the altitude of the auroral emission. The latter value is in agreement with temperatures obtained from H3+ infrared polar spectra. Self-absorption is detectable in the LiF2a segment for H[SUB]2[/SUB] columns exceeding 6×10[SUP][/SUP]cm[SUP][/SUP], which sets the maximum mean energy determined from the FUSE observations to Ë 15 keV. The total electron energy range of 10 18 keV deduced from FUV and EUV observations places the auroral emission peak between the 0.1 and 0.3 mubar pressure levels. These values should be seen as an upper limit, since most of the Voyager UVS spectra of Saturn's aurora examined by Sandel et al. [Sandel, B.R., Shemansky, D.E., Broadfoot, A.L., Holberg, J.B., Smith, G.R., 1982. Science 215, 548] do not exhibit methane absorption. The auroral H[SUB]2[/SUB] emission is thus likely located above but close to the methane homopause. The H[SUB]2[/SUB] auroral brightness in the 800 1700 Å bandwidth varies from 2.9 kR to 139 kR, comparable to values derived from FUV Faint Object Camera (FOC) and STIS images. [less ▲]

Detailed reference viewed: 57 (22 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of the infestation of Seriatopora corals by the coral gall crab Hapalocarcinus marsupialis Stimpson, 1859 on the great reef of toliara, Madagascar
Terrana, Lucas; Caulier, Guillaume; Todinanahary, Gildas et al

in Symbiosis (2016), 69(2), 113-122

This study describes the association between the obligatory symbiont coral gall crab Hapalocarcinus marsupialis and its stony coral hosts Seriatopora sp .within the Great Reef of Toliara in Madagascar and ... [more ▼]

This study describes the association between the obligatory symbiont coral gall crab Hapalocarcinus marsupialis and its stony coral hosts Seriatopora sp .within the Great Reef of Toliara in Madagascar and attempts to dis- cuss their symbiotic status through comparison with previous studies. These corals are inhabited by crabs living in galls that can be categorised in four distinct morphological stages, where the first one corresponds to a small bud and the last one represents a completely closed gall surrounding the crab inside. Within the reef, 563 colonies of Seriatopora species were observed by scuba-diving at ten different stations: 37.8 % of them were infested by H. marsupialis , with a total of 763 galls, and with a majority of stage 4 galls. Galls are monopolised by females that can have different morphologies. Females store the sperm in two spermathecae and are fertilised when their morphology and size are similar to males and the gall is not closed. Histological observations coupled with scanning electronic microscopy analyses show that closed galls are made of an external living tissue, a mid skeletal layer and an internal living tissue. The internal living tissue includes polyps similar to the external tissue, some of them being sex- ually mature. Nitrogen and carbon isotopic signatures confirmed that these crabs are filter-feeders and do not feed on their host. This association perfectly highlights the difficul- ties to define the symbiotic status of a symbiont if one con- siders inflexible the three categories of symbiosis commonly defined. [less ▲]

Detailed reference viewed: 27 (3 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of the iron moment in Dy-Fe and Dy-FeCo amorphous alloys studied by X-ray magnetic circular dichroism
Fleury-Frenette, Karl ULg; Dhesi, S. S.; van der Laan, G. et al

in Journal of Magnetism & Magnetic Materials (2000), 220(1), 45-51

The local magnetic moment of Fe in Dy-Fe and Dy-FeCo amorphous alloys has been studied using X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD). The Fe orbital and spin magnetic ... [more ▼]

The local magnetic moment of Fe in Dy-Fe and Dy-FeCo amorphous alloys has been studied using X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD). The Fe orbital and spin magnetic moments have been obtained for a range of alloy compositions by applying the sum rules to the XMCD spectra. The room temperature variations of the average components of the Fe moments as a function of Dy concentration and with the substitution of Fe by Co have been determined. A sharp reversal of the total magnetic moment was found at 28 +/- 1 at% Dy for both alloys. (C) 2000 Elsevier Science B.V. All rights reserved. [less ▲]

Detailed reference viewed: 35 (4 ULg)
Full Text
Peer Reviewed
See detailThe characteristics of the O2 Herzberg II and Chamberlain bands observed with VIRTIS/Venus Express
Migliorini, A.; Piccioni, G.; Gérard, Jean-Claude ULg et al

in Icarus (2013)

The oxygen Venus nightglow emissions in the visible spectral range have been known since the early observations from the Venera spacecraft. Recent observations with the VIRTIS instrument on board Venus ... [more ▼]

The oxygen Venus nightglow emissions in the visible spectral range have been known since the early observations from the Venera spacecraft. Recent observations with the VIRTIS instrument on board Venus Express allowed us to re-examine the Herzberg II system of O2 and to further study its vertical distribution, in particular the (0–m00 with m00 = 7–13) bands. The present work describes the vertical profile of the observed bands and relative intensities from limb observation data. The wavelength-integrated intensities of the Herzberg II bands, with m00 = 7–11, are inferred from the recorded spectra. The resulting values lie in the range of 84–116 kR at the altitudes of maximum intensity, which are found to lie in the range of 93–98 km. Three bands of the Chamberlain system, centered at 560 nm, 605 nm, and 657 nm have been identified as well. Their emission peak is located at about 100 km, 4 km higher than the Herzberg II bands. For the first time, the O2 nightglow emissions were investigated simultaneously in the visible and in the IR spectral range, showing a good agreement between the peak position for the Herzberg II and the O2ða1Dg—X3R g Þ bands. An airglow model, proposed by Gérard et al. (Gérard, J.C., Soret, L., Migliorini, A., Piccioni, G. [2012]. Icarus.) starting from realistic O and CO2 vertical distributions derived from Venus-Express observations, allows reproduction of the observed profiles for the three O2 systems. [less ▲]

Detailed reference viewed: 43 (8 ULg)
Peer Reviewed
See detailCharacteristics of the pulsatile liberation of LH in Italian Simmental cows from the dry period to early lactation
Prandi, Alberto; Motta, Mario; Rossi, A. et al

in Bulletin des Recherches Agronomiques de Gembloux (1995), 30

Detailed reference viewed: 17 (0 ULg)
Full Text
Peer Reviewed
See detailCharacteristics of the size distribution of recent and historical landslides in a populated hilly region
Van den Eeckhaut, M.; Poesen, J.; Govers, G. et al

in Earth and Planetary Science Letters (2007), 256(3-4), 588-603

Despite the availability of studies on the frequency density of landslide areas in mountainous regions, frequency-area distributions of historical landslide inventories in populated hilly regions are ... [more ▼]

Despite the availability of studies on the frequency density of landslide areas in mountainous regions, frequency-area distributions of historical landslide inventories in populated hilly regions are absent. This study revealed that the frequency-area distribution derived from a detailed landslide inventory of the Flemish Ardennes (Belgium) is significantly different from distributions usually obtained in mountainous areas where landslides are triggered by large-scale natural causal factors such as rainfall, earthquakes or rapid snowmelt. Instead, the landslide inventory consists of the superposition of two populations, i.e. (i) small (<1-2 . 10(-2) km(2)), shallow complex earth slides that are at most 30 yr old, and (ii) large (> 1-2 . 10(-2) km(2)), deep-seated landslides that are older than 100 yr. Both subpopulations are best represented by a negative power-law relation with exponents of -0.58 and -2.31 respectively. This study focused on the negative power-law relation obtained for recent, small landslides, and contributes to the understanding of frequency distributions of landslide areas by presenting a conceptual model explaining this negative power-law relation for small landslides in populated hilly regions. According to the model hilly regions can be relatively stable under the present-day environmental conditions, and landslides are mainly triggered by human activities that have only a local impact on slope stability. Therefore, landslides caused by anthropogenic triggers are limited in size, and the number of landslides decreases with landslide area. The frequency density of landslide areas for old landslides is similar to those obtained for historical inventories compiled in mountainous areas, as apart from the negative power-law relation with exponent -2.31 for large landslides, a positive power-law relation followed by a rollover is observed for smaller landslides. However, when analysing the old landslides together with the more recent ones, the present-day higher temporal frequency of small landslides compared to large landslides, obscures the positive power-law relation and rollover. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 25 (3 ULg)