Plasma gossypol dynamics in white-tailed deer: Implications for whole cottonseed as a supplemental feed

Whole cottonseed (WCS) is a potential supplemental feed for white-tailed deer (Odocoileus virginianus) in rangeland conditions because of its high digestible energy and protein content, moderate fiber content, and resistance to degradation in moist conditions. WCS also contains the polyphenolic secondary metabolite gossypol, which reduces palatability to non-target monogastric species but may be of concern for deer nutrition. Plasma gossypol stabilization when fed a constant dry matter intake, plasma gossypol depletion after WCS was removed from the diet, and the relationship between WCS consumption and plasma gossypol concentration was studied in 10 mature male (N = 5) and female (N = 5) captive white-tailed deer. Consumption of WCS by 73 free-ranging white-tailed deer (59 males, 14 females) was estimated using results of the captive study. Plasma gossypol concentrations declined exponentially and averaged 0.74 μg/mL 35 days after WCS was removed from the diet. Plasma gossypol concentration was linearly related to WCS consumption (P < 0.001), with females having 0.35 μg/mL greater (P = 0.04) plasma gossypol than males for a given rate of dry matter consumption. All female and 93% of male white-tailed deer captured in WCS supplemented pastures had detectable plasma gossypol. Female averaged 1.88 μg/mL of plasma gossypol and males averaged 4.84 μg/mL of plasma gossypol. Based on the captive deer data, these plasma values suggest an average WCS consumption of ∼2.6 g/kg BW/day for female free-ranging deer and ∼5.6 g/kg BW/day for male free-ranging deer. Inferentially, a large proportion of free-ranging white-tailed deer in rangeland conditions will consume WCS, with females consuming 125 g WCS/day and males consuming 428 g WCS/day. That plasma gossypol levels decrease rapidly after cottonseed is removed from the diet suggests that the long withdrawal periods often used prior to breeding season may not be needed. However, although 93% of gossypol was eliminated from the animals after a five-week withdrawal period, a small amount of gossypol can still be detected. While our preliminary data on these animals suggests that these levels are not detriment to animal health or reproduction, ranch managers may want to take a conservative approach to the feeding of WCS until these questions are answered.     

Contraceptive efficacy of a novel intrauterine device (IUD) in white-tailed deer

Overabundant white-tailed deer (Odocoileus virginianus) pose risks to property, health, and safety of human beings. Public concerns about lethal management can impair efforts to address these issues, particularly in urban settings. Several techniques developed for reducing reproductive output of deer have limited utility because they require repeated dosing to achieve permanent effect and face uncertain regulatory approval for use beyond experimentation. From 10 August 2006 through 30 December 2007, we evaluated the contraceptive efficacy of copper-containing intrauterine devices (IUDs) implanted trans-cervically in white-tailed deer at the E.S. George Reserve in Pinckney, Michigan. Intrauterine devices were implanted before (n = 9) and shortly after (n = 10) the breeding season. Post-breeding season IUD treatment was in conjunction with a 5 cm³ dose of 5 mg/ml prostaglandin F_2α (PGF_2α), delivered subcutaneously. Intrauterine devices reduced pregnancy rates when administered prior to breeding (P < 0.001) and prevented pregnancy for up to 2 years (the duration of the study). Two of 8 does that received IUDs prior to the breeding season and survived to the end of the study became pregnant (due to loss of the implant) during the second year while all (n = 16) does without implants conceived. Cervical changes associated with early pregnancy made trans-cervical implantation after the breeding season challenging, and resulted in improperly placed IUDs in 2 treated does. The apparent expulsion of IUDs by pregnant does that received the combined treatment after breeding suggests IUD treatment should be limited to the pre-breeding season. Intrauterine devices show potential as a tool for small-scale deer population management via non-steroidal reproductive inhibition.     

Estimating roe deer abundance from pellet group counts in Spain: An assessment of methods suitable for Mediterranean woodlands

Despite of the generalized expansion of wild ungulates in Europe, roe deer (Capreolus capreolus) is experiencing contrasted population trends; it is expanding in some regions while declining in others likely due to the expansion of other deer species. In both extremes, reliable methods to estimate population abundance are required. We evaluated different methods of estimating deer abundance in Mediterranean woodlands based on pellet group counts. Distance Sampling applied to pellet counts and a new easier and cost-effective method based on strip-variable transect counts (FST) were assessed comparing their estimates (pellet group density) with the abundance indices obtained from traditionally used reference methods (faecal standing crop) in 61 localities (n = 183 surveys). The average roe deer density estimated from faecal standing crop was 5.56 ± 0.75 (range 0.01–20.74) deer per 100 ha. Distance Sampling and FST estimates correlated with reference methods. As a first conclusion it may be noted that all indirect methods used here can be used to estimate roe deer abundance. The selection of a given method based on pellet counts to estimate roe deer population abundance should take into account the specific objectives of the research, resources available, and the timescale in which the information is required. Among them, Distance Sampling may be used when human resources and skills are enough but FST is a rapid and efficient alternative to estimate pellet group density when they are not.     

Camera traps reveal an apparent mutualism between a common mesocarnivore and an endangered ungulate

Camera traps are commonly used to study mammal ecology and they occasionally capture previously undocumented species interactions. The key deer (Odocoileus virginianus clavium) is an endangered endemic subspecies of the Florida Keys, where it exists with few predators. We obtained a camera trap sequence of 80 photos in which a key deer interacted with two northern raccoons (Procyon lotor). One of the raccoons groomed the deer’s face for ∼1 min. This interaction is peculiar and appears mutualistic because the deer was not concerned and willingly remained still throughout the physical contact. Although mutualistic relationships between deer and birds are common, we are unaware of any previously documented mesocarnivore-deer mutualisms. Key deer have evolved in the absence of mammalian predators and we hypothesize that they exhibit reduced vigilance or concern when encountering other species because of predator naivety. Key deer and raccoons are commonly associated with humans and urbanization and an alternative hypothesis is that the interactions are a consequence of heightened deer density, causing a greater probability of sustained interactions with the common mesocarnivores.     

Sulforaphane improves dysregulated metabolic profile and inhibits leptin-induced VSMC proliferation: Implications toward suppression of neointima formation after arterial injury in western diet-fed obese mice

Sulforaphane (SFN), a dietary phase-2 enzyme inducer that mitigates cellular oxidative stress through nuclear factor erythroid 2-related factor 2 (Nrf2) activation, is known to exhibit beneficial effects in the vessel wall. For instance, it inhibits vascular smooth muscle cell (VSMC) proliferation, a major event in atherosclerosis and restenosis after angioplasty. In particular, SFN attenuates the mitogenic and pro-inflammatory actions of platelet-derived growth factor (PDGF) and tumor necrosis factor-α (TNFα), respectively, in VSMCs. Nevertheless, the vasoprotective role of SFN has not been examined in the setting of obesity characterized by hyperleptinemia and insulin resistance. Using the mouse model of western diet-induced obesity, the present study demonstrates for the first time that subcutaneous delivery of SFN (0.5 mg/Kg/day) for ~ 3 weeks significantly attenuates neointima formation in the injured femoral artery [↓ (decrease) neointima/media ratio by ~ 60%; n = 5–8]. This was associated with significant improvements in metabolic parameters, including ↓ weight gain by ~ 52%, ↓ plasma leptin by ~ 42%, ↓ plasma insulin by ~ 63%, insulin resistance [↓ homeostasis model assessment of insulin resistance (HOMA-IR) index by ~ 73%], glucose tolerance (↓ AUC_GTT by ~ 24%), and plasma lipid profile (e.g., ↓ triglycerides). Under in vitro conditions, SFN significantly decreased leptin-induced VSMC proliferation by ~ 23% (n = 5) with associated diminutions in leptin-induced cyclin D1 expression and the phosphorylation of p70S6kinase and ribosomal S6 protein (n = 3–4). The present findings reveal that, in addition to improving systemic metabolic parameters, SFN inhibits leptin-induced VSMC proliferative signaling that may contribute in part to the suppression of injury-induced neointima formation in diet-induced obesity.     

Sap flow and water use in African baobab (Adansonia digitata L.) seedlings in response to drought stress

The African baobab (Adansonia digitata L.) is an important multi-purpose fruit tree with high potential for domestication in drier Africa. Although adult individuals are well-known to be drought resistant, only little has been reported on how young baobab trees can survive drought. Therefore, the aim of this study was to examine short-term soil drought effects on water relations of baobab seedlings. Baobab seedlings used a limited amount of stored water to buffer daily water deficits (~ 8.5 g d^− 1), which contributed up to only ~ 17.5% of daily water use and ~ 6% of total plant water. Under drought, a strong reduction in stomatal conductance (~ 85%) resulted in a midday leaf water potential of − 1 MPa and zero stem sap flow followed by significant leaf loss. Plant anatomy evidenced the presence of water storage tissues and the vulnerability to xylem embolism. The taproot was the most important plant part for water storage (68% of total plant water), suggesting root-succulence rather than stem-succulence. When drought intensified, limitation of leaf transpiration and/or root water uptake led to drought-enforced dormancy. Despite the large amounts of water stored in the taproot (~ 90%) and the stem (~ 75%), only a limited amount of stored water appeared to be used to sustain upper leaves and plant metabolism during the dormant period, and to facilitate recovery following water supply. Drought avoidance, conservative water use and the presence of internal stored water allow baobab seedlings to survive drought.     

Rhaetian magneto-biostratigraphy from the Southern Alps (Italy): Constraints on Triassic chronology

New Late Triassic–earliest Jurassic magneto-biostratigraphic data have been obtained from three overlapping sections in the Southern Alps, Italy (Costa Imagna, Brumano, Italcementi Quarry), composed of ~ 520 m of shallow-marine carbonates outcropping in stratigraphic continuity. Characteristic magnetic components of presumed depositional age record a sequence of 9 normal and reverse polarity magnetozones (as defined by at least three stratigraphically superposed samples) linked by conodont and palynofloral evidence from this study and the literature to Rhaetian to Triassic–Jurassic boundary age. This represents a significantly larger number of polarity zones than previously recognized in more condensed Rhaetian sections from the literature, and by inference represents more time. These data are placed in a broader Late Triassic temporal framework by means of correlations to published magneto-biostratigraphic data from the Tethyan marine Pizzo Mondello section and the Newark astronomical polarity time scale (APTS). This framework is consistent with a position of the Norian–Rhaetian boundary (as defined at Brumano and Pizzo Mondello by the first appearance of Misikella posthernsteini) within Newark magnetozones E17r–E19r in the ~ 207–210 Ma time interval, in basic agreement with the position originally estimated in the Newark using pollen biostratigraphy (E18 at 208–209 Ma). This framework is also consistent with the position of the Triassic–Jurassic boundary interval (placed at Italcementi Quarry at the acme of Kraeuselisporites reissingeri coincident with a negative carbon isotope excursion) correlative to just above Newark magnetozone E23r and just below the oldest CAMP lavas dated at ~ 202 Ma. Hence, we estimate the duration of the Rhaetian to be ~ 5.5–8.5 Myr (or even longer if the Triassic–Jurassic boundary is instead placed above the negative carbon isotope excursion as at Kuhjoch, which is the designated GSSP for the base of the Hettangian), and encompassing 9 magnetozones. This duration contrasts with a duration of ~ 2 Myr and only ~ 4 magnetozones in several alternative published magneto-biostratigraphic schemes.     

A new stage 3 millennial climatic variability record from a SW France speleothem

We present a new high resolution speleothem stable isotope record from the Villars Cave (SW-France) that covers part of marine isotope stage (MIS) 3. The Vil14 stalagmite grew between ~ 52 and 29 ka. The δ¹³C profile is used as a palaeoclimate proxy and clearly shows the interstadial substages 13, 12 and 11. The new results complement and corroborate previously published stalagmite records Vil9 and Vil27 from the same site. The Vil14 stalagmite chronology is based on 12 Th-U dating by MC-ICP-MS and 3 by TIMS. A correction for detrital contamination was done using the ²³⁰Th/²³²Th activity ratio measured on clay collected in Villars Cave. The Vil14 results reveal that the onset of Dansgaard–Oeschger (DO) events 13 and 12 occurred at ~ 49.8 ka and ~ 47.8 ka, respectively. Within uncertainties, this is coherent with the latest NorthGRIP time scale (GICC05-60 ka) and with speleothem records from Central Alps. Our data show an abrupt δ¹³C increase at the end of DO events 14 to 12 which coincides with a petrographical discontinuity probably due to a rapid cooling. As observed for Vil9 and Vil27, Vil14 growth significantly slowed down after ~ 42 ka and finally stopped ~ 29 ka ago where the δ¹³C increase suggests a strong climate deterioration that coincides with both North Atlantic sea level and sea surface temperature drop.     

Structural changes that occur upon photolysis of the Fe(II)a3–CO complex in the cytochrome ba3-oxidase of Thermus thermophilus: A combined X-ray crystallographic and infrared spectral study demonstrates CO binding to CuB

The purpose of the work was to provide a crystallographic demonstration of the venerable idea that CO photolyzed from ferrous heme-a₃ moves to the nearby cuprous ion in the cytochrome c oxidases. Crystal structures of CO-bound cytochrome ba₃-oxidase from Thermus thermophilus, determined at ~ 2.8–3.2 Å resolution, reveal a Fe–C distance of ~ 2.0 Å, a Cu–O distance of 2.4 Å and a Fe–C–O angle of ~ 126°. Upon photodissociation at 100 K, X-ray structures indicate loss of Fe_a3–CO and appearance of Cu_B–CO having a Cu–C distance of ~ 1.9 Å and an O–Fe distance of ~ 2.3 Å. Absolute FTIR spectra recorded from single crystals of reduced ba₃–CO that had not been exposed to X-ray radiation, showed several peaks around 1975 cm^? 1; after photolysis at 100 K, the absolute FTIR spectra also showed a significant peak at 2050 cm^? 1. Analysis of the ‘light’ minus ‘dark’ difference spectra showed four very sharp CO stretching bands at 1970 cm^? 1, 1977 cm^? 1, 1981 cm^? 1, and 1985 cm^? 1, previously assigned to the Fe_a3–CO complex, and a significantly broader CO stretching band centered at ~ 2050 cm^? 1, previously assigned to the CO stretching frequency of Cu_B bound CO. As expected for light propagating along the tetragonal axis of the P4₃2₁2 space group, the single crystal spectra exhibit negligible dichroism. Absolute FTIR spectrometry of a CO-laden ba₃ crystal, exposed to an amount of X-ray radiation required to obtain structural data sets before FTIR characterization, showed a significant signal due to photogenerated CO₂ at 2337 cm^? 1 and one from traces of CO at 2133 cm^? 1; while bands associated with CO bound to either Fe_a3 or to Cu_B in “light” minus “dark” FTIR difference spectra shifted and broadened in response to X-ray exposure. In spite of considerable radiation damage to the crystals, both X-ray analysis at 2.8 and 3.2 Å and FTIR spectra support the long-held position that photolysis of Fe_a3–CO in cytochrome c oxidases leads to significant trapping of the CO on the Cu_B atom; Fe_a3 and Cu_B ligation, at the resolutions reported here, are otherwise unaltered. This article is part of a Special Issue entitled: Respiratory Oxidases.     

Step-wise change of Asian interior climate preceding the Eocene–Oligocene Transition (EOT)

Understanding the global climate change from greenhouse to icehouse conditions at the Eocene–Oligocene Transition (EOT) 34 million years ago requires climatic records from oceanic as well as continental realms of the key Late Eocene “doubthouse” period preceding this switch. Here, we report integrated stratigraphic results from well-dated Late Eocene continental mudflat to saline lake paleoenvironments of the Xining Basin (northeastern Tibetan Plateau, western China) recording regional and global change. Cyclostratigraphic analysis strongly suggests continuous dominance of the 41-kyr obliquity cycle in the whole late Eocene interval down to the base of polarity chron C18n.2n at 39 Ma with additional input of the ~ 100-kyr eccentricity cycle up to the base of chron C13r at ~ 34.7 Ma. This might imply that high-latitude climates dominated the area long before the EOT, probably related to incipient ice-volume fluctuations. Furthermore, our results reveal two paleoenvironmental deterioration steps preceding the Eocene–Oligocene Transition. The first step occurs in the top of chron C17n.1n at ~ 36.6 Ma. This age closely corresponds to (1) the high-altitude pollen appearance in chron C16.2r at ~ 36.4 Ma in the same section, (2) the recently dated final retreat of the Tarim Sea in western China, and (3) a shift from precession to obliquity dominance in the Atlantic Ocean. This near co-occurrence suggests global change at this time. We hypothesize this change is related to an increase in incipient ice sheet volume leading to passing threshold conditions for the high-altitude pollen appearance and Tarim Sea retreat, finally leading to decreased moisture availability in the Xining Basin. At the second step, in the base of chron C13r at ~ 34.7 Ma, a substantial increase in clastic sedimentation rates is observed. This might relate to increased climate variability preceding the greenhouse to icehouse transition at the EOT that prevented landscapes to attain equilibrium configurations.     

Segmentation d’images de lésions cérébrales primitives en TEP FET : influence du volume de travail

Purpose(1) Evaluate the reproducibility of segmentation methods depending on the preselection region for tumour volume determination on ¹⁸F-fluoro-ethyl-tyrosine (FET) PET. (2) Evaluate the intra and inter-operator reproducibility of the manual delineation. (3) Compare this delineation with the segmentation methods.Materials and methodsEighteen FET PET of patients with glioblastoma were analysed. Preselection regions were determined prior to any segmentation. Two physicians delineated the tumour volume manually. The tumour volume was also delineated with a threshold method (40 and 70% of SUV_max), and a random walk based method. Pearson coefficient (r) (P < 0.05 for r > 0.468) and Jaccard indices (JI) were used to compare the volumes.ResultsManual delineation was reproducible with r = 0.97 and IJ = 0.65 for intra-operator, and r = 0.76 and IJ = 0.45 for inter-operator reproducibility. The preselection regions for a given lesion were different and the segmentation varied with the preselection region: r = 0.55 JI = 0.58; r = 0.85 JI = 0.83; r = 0.70 JI = 0.39 respectively for the threshold of 40%, 70% and the random walk. The segmentation differed form de manual delineation with r = 0.37 and JI = 0.16; r = 0.54 and JI = 0.42; r = 0.43 and JI = 0.37 respectively for the threshold of 40%, 70% and the random walk.ConclusionThe reproducibility of the segmentation methods depends extensively on the preselection region. The intra-operator reproducibility of cerebral lesion delineation on FET PET is satisfactory. The inter-operator reproducibility could be improved.     

Digestive capacities allow the Mexican long-nosed bat (Leptonycteris nivalis) to live in cold environments

Digestive capabilities of nectar-feeding vertebrates to assimilate sugars affect their ability to acquire and store energy and could determine the minimal temperatures at which these animals can survive. Here, we described the sugar digestive capability of Leptonycteris nivalis and related it with its capacity to live in cold environments. We measured the enzymatic activity, food intake rate and changes in body mass of bats feeding at four different sucrose concentrations (from 5 to 35% wt./vol.). Additionally, we used a mathematical model to predict food intake and compared it with the food intake of bats. L. nivalis was able to obtain ~ 111.3 kJ of energy regardless of the sugar concentration of their food. Also, bats gained ~ 2.57 g of mass during the experimental trials and this gain was independent of sugar concentration. The affinity (1 / K_m) of sucrase (EC 3.2.1.48) was one order of magnitude higher relative to that reported for its sister species Leptonycteris yerbabuenae (0.250 and 0.0189 mmol^? 1 L, respectively), allowing this species to have a higher energy intake rate. We propose that the high ability to acquire energy conferred L. nivalis the faculty to invade cold environments, avoiding in this way the ecological competition with its sympatric species L. yerbabuenae.     

Analysis of the germination rate,mitotic index and karyotype of Chromolaena barranquillensis (Hieron.) R.M. King & H. Rob.—Asteraceae

Chromolaena barranquillensis (Asteraceae) is an endemic plant of northern Colombia that has garnered economic and medicinal interest, because species from the genus Chromolaena have shown diverse biological activities. This study describes, for the first time, the karyotype, germination and mitotic indices of C. barranquillensis (Hieron.) R.M. King & H. Rob. The germination index was between 34% and 56% with an average germination rate of 1.2 ± 0.4 seeds/day. The mitotic index analysis allowed to determine the cell cycle time (4 h, 10 min) and the mitotic hours (3:00–8:00 h and 17:00 h). The mitosis time was 49 min, equivalent to ~ 20% of the cell cycle. Karyotype analysis showed that C. barranquillensis is a hexaploid species with a chromosomal formula 2n = 6x = 60 = 48 m + 12 sm, and the average chromosomal lengths were 1.7 ± 0.1 μm to 0.9 ± 0.3 μm. The Stebbins asymmetry index was 2B, and the total form percentage was ~ 41%. These results uncover differences between C. barranquillensis and Chromolaena odorata, one of the most abundant species found in the world and the most closely related species to C. barranquillensis.     

Regulation of Shigella Effector Kinase OspG through Modulation of Its Dynamic Properties

Gram-negative pathogens secrete effector proteins into human cells to modulate normal cellular processes and establish a bacterial replication niche. Shigella and pathogenic Escherichia coli possess homologous effector kinases, OspG and NleH1/2, respectively. Upon translocation, OspG but not NleH binds to ubiquitin and a subset of E2 ~ Ub conjugates, which was shown to activate its kinase activity. Here we show that OspG, having a minimal kinase fold, acquired a novel mechanism of regulation of its activity. Binding of the E2 ~ Ub conjugate to OspG not only stimulates its kinase activity but also increases its optimal temperature for activity to match the human body temperature and stabilizes its labile C-terminal domain. The melting temperature (T_m) of OspG alone is only 31?°C, as compared to 41?°C to NleH1/2 homologs. In the presence of E2 ~ Ub, the T_m of OspG increases to ~ 42?°C, while Ub by itself increases the T_m to 39?°C. Moreover, OspG alone displays maximal activity at 26?°C, while in the presence of E2 ~ Ub, maximal activity occurs at ~ 42?°C. Using NMR and molecular dynamics calculations, we have identified the C-terminal lobe and, in particular, the C-terminal helix, as the key elements responsible for lower thermal stability of OspG as compared to homologous effector kinases.     

Deformable registration-based segmentation of the bowel on Megavoltage CT during pelvic radiotherapy

During pelvic radiotherapy bowel loops (BL) are subject to inter-fraction changes. MVCT images have the potential to provide daily bowel segmentation. We assess the feasibility of deformable registration and contour propagation in replacing manual BL segmentation on MVCT.Four observers delineated BL on the planning kVCT and on one therapy MVCT in eight patients. Inter-observer variations in BLs contouring were quantified using DICE index. BLs were then automatically propagated onto MVCT by a commercial software for image deformation and subsequently manually corrected. The agreement between propagated BL/propagated + manually corrected BL vs manual were quantified using the DICE. Contouring times were also compared. The impact on DVH of using the deformable-registration method was assessed. The same procedures were repeated on high-resolution planning-kVCT and therapy-kVCT.MVCTs are adequate to visualize BL (average DICE: 0.815), although worse than kVCT (average DICE:0.889). When comparing propagated vs manual BL, a poor agreement was found (average DICE: 0.564/0.646 for MVCT/KVCT). After manual correction, average DICE indexes increased to 0.810/0.897. The contouring time was reduced to 15 min with the semi-automatic approach from 30 min with manual contouring. DVH parameters of propagated BL were significantly different from manual BL (p < 0.0001); after manual correction, no significant differences were seen.MVCT are suitable for BL visualization. The use of a software to segment BL on MVCT starting from BL-kVCT contours was feasible if followed by manual correction. The method resulted in a substantial reduction of contouring time without detrimental effect on the quality of bowel segmentation and DVH estimates.     

Fully automatic input function determination program for simple noninvasive 123I-IMP microsphere cerebral blood flow quantification method

We recently developed a simple noninvasive ¹²³I-IMP microsphere (SIMS) method using chest dynamic planar images and brain single photon emission computed tomography. The SIMS method is an automatic analysis method, except for the process of setting the region of interest (ROI) of the input function. If a fully automatic ROI setting algorithm can be developed to determine the input function for the SIMS method, repeatability and reproducibility of the analysis of regional cerebral blood flow (rCBF) of the SIMS method can be guaranteed. The purpose of this study is to develop a fully automatic input function determination program for the SIMS method and to confirm the clinical usefulness of this program.The automatic input function determination program consists of two ROI setting programs for the PA and lung regions, and it is developed using the image phase analysis of a chest RI angiogram. To confirm the clinical usefulness of this program, the rCBF in 34 patients measured using the automatic method were compared with the values obtained through the manual setting method.Input functions by the automatic and manual methods were approximately equal. A good correlation was observed between the rCBF values obtained by the automatic method and those obtained by the manual setting method (r = 0.96, p < 0.01).Further, the total time taken for the automatic SIMS analysis is 1–2 min as compared to 20–30 min for the current analysis, and therefore, this technique contributes to the improvement of the throughput of nuclear medical examinations.     

Contribution of several nitrogen sources to growth of Alexandrium catenella during blooms in Thau lagoon,southern France

A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001–2004) in Thau lagoon. Nitrate and nitrite contributed 0.1–14% and 0.1–5% respectively of growth requirements. Ammonium and urea were the main N sources fueling growth of A. catenella (30–100% and 2–59%, respectively). Indirect estimates indicated that an unidentified N source could also contribute significantly to growth at specific times. Concerning ammonium and urea uptake kinetics, half-saturation constants varied between 0.2 and 20 μgat N L⁻¹ for ammonium and between 0.1 and 44 μgat N L⁻¹ over the 4-year period, indicating that A. catenella can have a competitive advantage over other members of the phytoplankton even under low concentrations of ammonium and urea. However, the observed large changes in ammonium and urea uptake kinetics on a short time scale (days) during blooms preclude more precise estimates of those contributions to growth and require further investigation.     

Habitat selection by endangered Himalayan musk deer (Moschus chrysogaster) and impacts of livestock grazing in Nepal Himalaya: Implications for conservation

Habitat management within and outside protected areas is a key to effective conservation of wildlife. This is particularly vital for declining wildlife populations within the boundary of conservation areas, while sharing their potential habitat range with foraging livestock. In an effort to understand the habitat selection by Himalayan musk deer (Moschus chrysogaster) and explore any potential impacts of livestock grazing, we conducted the present study in a conservation area of central Nepal Himalaya. We recorded data on musk deer and livestock presence and absence (based on signs of fecal pellet, footprint, and resting site) along the elevational transect with associated topographic features (elevation, slope, aspect, distance to water, and vantage point distance) and vegetation features (tree spp., shrub spp., herb spp., and canopy-cover). Using logistic regression model we found that elevation, aspect, canopy-cover, and tree spp. in the area significantly affect the likelihood of habitat selection by musk deer. In particular, they selected the southern aspect of the area with elevation ≥ 3529 m, canopy-cover ≥ 42%, and with stands of Pinus spp. and Abies spp. Slope and canopy-cover significantly affected the foraging area selection by livestock. They selected the gentler slopes in the northern aspect of the area with altitude < 3529 m and canopy-cover < 42%. Also, presence of one group of herbivore (i.e. musk deer and livestock) was not found to affect the likelihood of habitat selection by the other group. These independent habitat selections are possibly the responses to morphological and behavioral adaptations than to impacts and interactions between these two groups of herbivores. We suggest to avoid any disturbances and livestock grazing on the area that disrupt the resources and conditions likely selected and occupied by musk deer population.     

Environmental and climatic changes in the central Mediterranean Sea (Siculo–Tunisian Strait) during the last 30 ka based on dinoflagellate cyst and planktonic foraminifera assemblages

A high resolution micropalaeontological study of the core MD 04-2797 CQ recovered in the Sicilian–Tunisian Strait provides insights into the paleoclimatic history of the Mediterranean Sea at the transition between the western and eastern basin over the last 30 ka. Using the analysis of dinoflagellate cyst and planktonic foraminiferal assemblages, we reconstruct the paleoenvironmental changes that took place in this region. High abundances of cold temperate dinocyst species (Nematosphaeropsis labyrinthus, Spiniferites elongatus, Bitectatodinium tepikiense) and the polar planktonic foraminifera Neogloboquadrina pachyderma (left coiling) reveal three major cooling events synchronous with North Atlantic Henrich events 1 and 2 (H1 and H2) and the European and North Atlantic Younger Dryas event. During the Holocene, the presence of warm dinocyst species (Spiniferites mirabilis and Impagidinium aculeatum) and planktonic foraminifera (Globorotalia inflata and Globigerinoides ruber), reflects a significant increase of sea surface temperatures in the western Mediterranean basin, but a full warming was not recorded until 1500 years after the onset of the Holocene. Moreover, our results show that the Holocene was interrupted by at least four brief cooling events at ~ 9.2 ka, ~ 8 ka, ~ 7 ka and ~ 2.2 ka cal. BP, which may be correlated to climatic events recorded in Greenland ice cores and in the Atlantic Ocean.