Scientific contributions of citizen science applied to rare or threatened animals

Citizen science is filling important monitoring gaps and thus contributing to the conservation of rare or threatened animals. However, most researchers have used peer-reviewed publications to evaluate citizen science contributions. We quantified a larger spectrum of citizen science's contributions to the monitoring of rare or threatened animals, including contributions to the peer-reviewed publications, gray literature and to conservation measures (i.e., actions taken as a direct result of citizen science monitoring). We sought to provide broad information on how results of studies of citizen science monitoring is used. We also evaluated factors associated with success of citizen science projects. We conducted a web search to find citizen science projects focusing on rare and threatened species and surveyed citizen science project managers about their contributions and factors influencing their success. The number of projects increased rapidly after 2010. Almost one-half of the citizen science projects produced at least 1 peer-reviewed publication, 64% produced at least 1 gray literature publication, and 64% resulted in at least 1 conservation measure. Conservation measures covered a wide range of actions, including management and mitigation plans, modification of threat status, identification and establishment of protected areas, habitat restoration, control of invasive species, captive breeding programs, and awareness campaigns. Longevity, data quality, and collaboration type best explained quantities of all types of scientific contributions of citizen science. We found that citizen science contributed substantially to knowledge advancement and conservation, especially when programs were long term and had rigorous data collection and management standards, and multidisciplinary or transdisciplinary collaborations.

Familiarity with visual stimuli boosts recency bias in macaques

To probe how non-human primates (NHPs) decode temporal dynamic stimuli, we used a two-alternative forced choice task (2AFC), where the cue was dynamic: a movie snippet drawn from an animation that transforms one image into another. When the cue was drawn from either the beginning or end of the animation, thus heavily weighted towards one (the target) of both images (the choice pair), then primates performed at high levels of accuracy. For a subset of trials, however, the cue was ambiguous, drawn from the middle of the animation, containing information that could be associated to either image. Those trials, rewarded randomly and independent of choice, offered an opportunity to study the strategy the animals used trying to decode the cue. Despite being ambiguous, the primates exhibited a clear strategy, suggesting they were not aware that reward was given non-differentially. More specifically, they relied more on information provided at the end than at the beginning of those cues, consistent with the recency effect reported by numerous serial position studies. Interestingly and counterintuitively, this effect became stronger for sessions where the primates were already familiar with the stimuli. In other words, despite having rehearsed with the same stimuli in a previous session, the animals relied even more on a decision strategy that did not yield any benefits during a previous session. In the discussion section we speculate on what might cause this behavioral shift towards stronger bias, as well as why this behavior shows similarities with a repetition bias in humans known as the illusory truth effect.

Global overview of the risk linked to the Bacillus cereus group in the egg product industry: identification of food safety and food spoilage markers

AIMS

To evaluate the food safety and spoilage risks associated with psychrotrophic Bacillus cereus group bacteria for the egg product industry and to search for relevant risk markers.

METHODS AND RESULTS

A collection of 68 psychrotrophic B. cereus group isolates, coming from pasteurized liquid whole egg products, was analysed through a principal component analysis (PCA) regarding their spoilage and food safety risk potentials. The principal component analysis showed a clear differentiation between two groups within the collection, one half of the isolates representing a safety risk and the other half a spoilage risk.

CONCLUSIONS

Relevant risk markers were highlighted by PCA, that is (i) for the food safety risk, the presence of the specific 16S rDNA-1m genetic signature and the ability to grow at 43°C on solid medium and (ii) for the spoilage risk, the presence of the cspA genetic signature.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work represents a first step in the development of new diagnostic technologies for the assessment of the microbiological quality of foods likely to be contaminated with psychrotrophic B. cereus group bacteria.

Contrast gain control and horizontal interactions in V1: a DCM study

Using high-density electrocorticographic recordings – from awake-behaving monkeys – and dynamic causal modelling, we characterised contrast dependent gain control in visual cortex, in terms of synaptic rate constants and intrinsic connectivity. Specifically, we used neural field models to quantify the balance of excitatory and inhibitory influences; both in terms of the strength and spatial dispersion of horizontal intrinsic connections. Our results allow us to infer that increasing contrast increases the sensitivity or gain of superficial pyramidal cells to inputs from spiny stellate populations. Furthermore, changes in the effective spatial extent of horizontal coupling nuance the spatiotemporal filtering properties of cortical laminae in V1 — effectively preserving higher spatial frequencies. These results are consistent with recent non-invasive human studies of contrast dependent changes in the gain of pyramidal cells elaborating forward connections — studies designed to test specific hypotheses about precision and gain control based on predictive coding. Furthermore, they are consistent with established results showing that the receptive fields of V1 units shrink with increasing visual contrast.

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A new observation model suitable for ECoG recordings.

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An canonical microcircuit field model.

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A DCM treatment of multiple experimental conditions and trial-specific effects.

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Excitation-inhibition balance in terms of strength and dispersion.

Visual cortical gamma-band activity during free viewing of natural images

Gamma-band activity in visual cortex has been implicated in several cognitive operations, like perceptual grouping and attentional selection. So far, it has been studied primarily under well-controlled visual fixation conditions and using well-controlled stimuli, like isolated bars or patches of grating. If gamma-band activity is to subserve its purported functions outside of the laboratory, it should be present during natural viewing conditions. We recorded neuronal activity with a 252-channel electrocorticographic (ECoG) grid covering large parts of the left hemisphere of 2 macaque monkeys, while they freely viewed natural images. We found that natural viewing led to pronounced gamma-band activity in the visual cortex. In area V1, gamma-band activity during natural viewing showed a clear spectral peak indicative of oscillatory activity between 50 and 80 Hz and was highly significant for each of 65 natural images. Across the ECoG grid, gamma-band activity during natural viewing was present over most of the recorded visual cortex and absent over most remaining cortex. After saccades, the gamma peak frequency slid down to 30–40 Hz at around 80 ms postsaccade, after which the sustained 50- to 80-Hz gamma-band activity resumed. We propose that gamma-band activity plays an important role during natural viewing.

Attentional stimulus selection through selective synchronization between monkey visual areas

A central motif in neuronal networks is convergence, linking several input neurons to one target neuron. In visual cortex, convergence renders target neurons responsive to complex stimuli. Yet, convergence typically sends multiple stimuli to a target, and the behaviorally relevant stimulus must be selected. We used two stimuli, activating separate electrocorticographic V1 sites, and both activating an electrocorticographic V4 site equally strongly. When one of those stimuli activated one V1 site, it gamma synchronized (60-80 Hz) to V4. When the two stimuli activated two V1 sites, primarily the relevant one gamma synchronized to V4. Frequency bands of gamma activities showed substantial overlap containing the band of interareal coherence. The relevant V1 site had its gamma peak frequency 2-3 Hz higher than the irrelevant V1 site and 4-6 Hz higher than V4. Gamma-mediated interareal influences were predominantly directed from V1 to V4. We propose that selective synchronization renders relevant input effective, thereby modulating effective connectivity.

Biodiversity of psychrotrophic bacteria of the Bacillus cereus group collected on farm and in egg product industry

The aim of the present study was (i) to type, by genotypic and phenotypic methods, a collection of psychrotrophic bacteria belonging to the Bacillus cereus group collected in a farm and in 6 egg breaking industries during a period covering a warm and a cold season, and (ii) to characterize the egg product spoilage (growth in liquid whole egg) and the sanitary risk potential (cytotoxic activity on Caco-2 cells and adhesion on stainless steel) of each isolate of the collection. The investigation of specific psychrotrophic and mesophilic signatures together with the study of ability to grow at 6 °C and/or at 43 °C on optimal agar medium allowed highlighting twelve profiles, the major one corresponding to the species Bacillus weihenstephanensis (46.2% of the collection). The diversity of the profiles depended on the season and on the origin of the isolates. In terms of food spoilage, all the isolates were able to grow at the same level in liquid whole egg and in optimal medium, even at low temperature. Under the same conditions, the cytotoxic activity depended on the isolate, the medium and the temperature. At 10 °C, no isolate was cytotoxic at 10 °C in liquid whole egg and only one, belonging to the Bacillus weihenstephansensis species, in the optimal medium. All the isolates were able to adhere on stainless steel at various levels, from 2.6±0.2 log cfu/cm(2) to 4.9±0.1 log cfu/cm(2). A large majority (80.8%) was strongly adhering and could lead to the formation of biofilms in industrial equipments.

Lithium prevents excitotoxic cell death of motoneurons in organotypic slice cultures of spinal cord

Several studies have reported the neuroprotective effects of lithium (Li) suggesting its potential in the treatment of neurological disorders, among of them amyotrophic lateral sclerosis (ALS). Although the cause of motoneuron (MN) death in ALS remains unknown, there is evidence that glutamate-mediated excitotoxicity plays an important role. In the present study we used an organotypic culture system of chick embryo spinal cord to explore the presumptive neuroprotective effects of Li against kainate-induced excitotoxic MN death. We found that chronic treatment with Li prevented excitotoxic MN loss in a dose dependent manner and that this effect was mediated by the inhibition of glycogen synthase kinase-3beta (GSK-3beta) signaling pathway. This neuroprotective effect of Li was potentiated by a combined treatment with riluzole. Nevertheless, MNs rescued by Li displayed structural changes including accumulation of neurofilaments, disruption of the rough endoplasmic reticulum and free ribosome loss, and accumulation of large dense core vesicles and autophagic vacuoles. Accompanying these changes there was an increase in immunostaining for (a) phosphorylated neurofilaments, (b) calcitonin gene-related peptide (CGRP) and (c) the autophagic marker LC3. Chronic Li treatment also resulted in a reduction in the excitotoxin-induced rise in intracellular Ca(2+) in MNs. In contrast to the neuroprotection against excitotoxicity, Li was not able to prevent normal programmed (apoptotic) MN death in the chick embryo when chronically administered in ovo. In conclusion, these results show that although Li is able to prevent excitotoxic MN death by targeting GSK-3beta, this neuroprotective effect is associated with conspicuous cytopathological changes.

[Validation of a diagnostic algorithm in non severe pulmonary embolism at the Annecy general hospital. D-dimers, venous lower limb ultra-sound and spiral CT scan]

OBJECTIVE AND METHOD

We have evaluated the sensitivity of a diagnostic algorithm for all patients suspected of pulmonary embolism using: D-Dimer, lower limb venous ultrasonography and helical computed tomography. To validate this approach, a lung scan is systematically carried out if the pulmonary embolism diagnosis is not withheld as a result of the algorithm. Clinical tests are organised between the 3rd and 6th month.

RESULTS

Two hundred patients were involved between January 1998 and October 1999. One hundred and six pulmonary embolisms were diagnosed. Out of the 200 ultrasonography tests carried out we found: 71 proximal deep-vein thrombosis (popliteal or supra-popliteal), 33 distal thrombosis (infra-popliteal). Ninety-two cases were negative (4 tests non conclusive). We have deduced that a deep-vein thrombosis permits the diagnosis of thrombo-embolic illness without any further diagnostic approach (no computed tomography). Out of the 129 computed tomographies carried out we found: 35 pulmonary embolisms and 23 other diagnoses. Seventy-one lung scans were therefore carried out. We recorded 7 discordances (scans showed high and very high probability for pulmonary embolism whilst computed tomographies did not): pulmonary angiography was negative 4 times and diagnosed pulmonary embolism once and two patients refused to take the test (Table 2). There are two recurrences in the follow-up: proximal thrombosis and a pulmonary embolism. This involved two patients who had refused to undergo pulmonary angiography.

CONCLUSION

This diagnostic approach therefore seems satisfactory but would require further investigation on a wider scale.

RhoGDI-3 regulates RhoG and targets this protein to the Golgi complex through its unique N-terminal domain

Guanine nucleotide dissociation inhibitors (GDIs) regulate both GDP/GTP and membrane association/dissociation cycles of Rho/Rac and Rab proteins.RhoGDI-3 is distinguishable from other rhoGDI proteins by its partial association with a detergent-resistant subcellular fraction. Here, we investigate the activity of this unusual rhoGDI using confocal laser scanning microscopy, immuno-isolation, and rhoGDI-3 mutants. We establish that the noncytosolic fraction of rhoGDI-3 is associated with the Golgi apparatus. The domain involved in this association is the unique N-terminal segment of rhoGDI-3 predicted to form an amphipathic alpha helix. This peptide is indispensable for Golgi association of rhoGDI-3 and sufficient to address a green fluorescent protein to the Golgi apparatus. Site-directed mutations, decreasing the hydrophobic surface of the helix, localize rhoGDI-3 into the cytoplasm. We establish that rhoGDI-3 is able to inhibit activation of the RhoG protein and to target this protein to the Golgi apparatus. Furthermore, we demonstrate the importance of the rhoGDI-3 N-terminal segment for both Golgi targeting and stability of the cytoplasmic RhoG/rhoGDI-3 complex. RhoGDI-3 is the first example of a GDI directly involved in the delivery of a Rho protein to a specific subcellular compartment.

[Health status and its effects on the work of national education nurses]

This study presents a pedagogical work carried out with a group of 13 school nurses of the Academy of Rennes, as part of a course in survey methodology. A descriptive survey aiming to achieve a better understanding of experienced health status of nurses, and of its repercussions on the execution of their missions, was implemented during the course, as a result of the demand and the expertise of the participants. Overall, nurses report to be in good health. However, one can not underestimate the existence of a group at risk (5% of the sample) that often suffers somatic troubles accompanied by sleep disorders and anxiety, as these risks concern primarily permanent staff nurses working in boarding establishments, with half of them falling into this category. A demand for regular monitoring of their health was clearly expressed through the study. This may be the object of a subsequent study by an academic team.

Immunocytochemical evidence for in vivo internalization of thyroliberin into rat pituitary target cells

The in vivo internalization of thyrotropin-releasing hormone (TRH) was studied by using a semiquantitative immunoelectron microscopic method. Pituitary glands of normal male rats intravenously injected with 100 ng TRH and sacrificed after 5-60 min were used. Ultrathin sections were obtained by cryoultramicrotomy of fixed pituitary glands. Pituitary cellular types were identified by appropriate antiserums. An antiserum specifically directed against TRH was used. TRH-like immunoreactivity due to endogenous TRH was observed in thyrotropes and prolactin cells, but never in somatotropes, gonadotropes or corticotropes. At the subcellular level, the reaction was detected within the cytoplasmic matrix, the secretory granules, and the nucleus but only occasionally at the plasma membrane. After in vivo injection of TRH, the immunocytochemical reaction was still restricted to thyrotropes and prolactin cells, increased with time elapsed after injection up to 15-30 min and then returned to basal intensity in cytoplasm, secretory granules, and nucleus, and became very frequent at the plasma membrane. These data provide evidence for endogenous TRH within thyrotropes and prolactin cells, i.e., in physiological target cells for TRH, and support the hypothesis that normal TRH target cells can, in vivo, internalize exogenous as well as endogenous TRH into several subcellular compartments including the nucleus.

Effects of thyroliberin (TRH) on cell proliferation and prolactin secretion by GH3/B6 rat pituitary cells: a comparison between serum-free and serum-supplemented media

Numerous studies have shown that prolactin (PRL) production by GH3 cells grown in serum supplemented media is regulated by several hormones including thyroliberin (TRH). The recent availability of hormonally defined, serum-free media for the growth of GH3 cells has made it possible to determine the effect of TRH in absence of other prolactin regulating hormones. Here we demonstrate that transfer of GH3/B6 cells from serum-supplemented medium to serum-free media results in several important changes: (1) altered growth response to TRH, (2) altered cell attachment and morphology, (3) greatly reduced prolactin production, and (4) greater stimulation of prolactin production by TRH. After 4 days in serum-free medium, TRH stimulates prolactin production by as much as 5-fold instead of approximately 2-fold in serum-supplemented medium. Furthermore, this increased responsiveness to TRH in serum-free medium is accompanied by a 10-fold decrease in the ED50 for TRH (concentration needed for half-maximal response) and paradoxically by a 2-fold reduction in the number of high-affinity TRH binding sites without significant change of their association constant.

Effect of 17 beta-estradiol on thyroliberin responsiveness in GH3/B6 rat prolactin cells

GH3/B6 rat prolactin cells were used to analyse at the cellular level the mechanisms by which 17 beta-estradiol (E2) regulates TRH responsiveness of prolactin cells. Before experiments, cells were grown for up to 7 days in 3 different media: normal medium (N) containing 15% horse serum and 2.5% fetal calf serum, CD medium prepared with charcoal-dextran extracted serum and CDE medium supplemented with 4 x 10(-8) M E2. The binding of 3H-TRH (30 min at 37 degrees C) and the TRH-induced percent increase of prolactin release as a function of TRH doses were compared in the 3 conditions. Preculture in E2 enriched medium increased by 50% the number of TRH high-affinity binding sites without modifying their affinity, increased by up to 3 times the percent of the TRH-induced stimulation of prolactin release and improved by one order of magnitude the ED50 of the TRH effect on prolactin release. The presence of HEPES (10 mM) during TRH challenge masked the effect of E2 on the increase in number of binding sites but respected its potentiating effect on prolactin release.

Increased binding of concanavalin A at the cell surface following exposure to thyroliberin

Thyroliberin (THR) binds specifically to SD1 rat prolactin cells and increases prolactin release. THR-induced modifications of surface membrane of intact SD1 cells were looked for, using concanavalin A (Con A) as a probe. At the electron microscope level the binding was restricted to the cell surface. Preexposure of the cells to TRH (27 nM) for 30 min at 37 degrees C increased the binding of Con A by 28--120%. Such an increase was not observed with low doses of TRH (13.5 and 2.7 nm) nor after only a 10-min exposure to 27 nM TRH. This effect is specific for TRH; it was not observed with other peptiDES. Simultaneous exposure to Con A and [3H] TRH did not alter [3H]TRH binding, but preexposure to Con A reduced the [3H]TRH binding by 10%, which may be due to steric hindrance. It is concluded that TRH induces an increased exposure of surface membrane glycoproteins in intact SD1 cells.