Technic for the morphometric study of cells in culture, about the in vitro stimulation of ovarian stroma cells by H.C.G

Sizes for ovarian stroma cells in culture are according to a log normal distribution. Cell stimulation by H.C.G. promotes a significative decrease of these sizes.     

First occurrence of early Homo in the Nachukui Formation (West Turkana, Kenya) at 2.3-2.4 Myr

Cognitive abilities and techno-economic behaviours of hominids in the time period between 2.6-2.3 Myr have become increasingly well-documented. This time period corresponds to the oldest evidence for stone tools at Gona (Kada Gona, West Gona, EG 10-12, OGS 6-7), Hadar (AL 666), lower Omo valley (Ftji1, 2 & 5, Omo 57, Omo 123) in Ethiopia, and West Turkana (Lokalalei sites -LA1 & LA2C-) in Kenya. In 2002 a new palaeoanthropological site (LA1alpha), 100 meters south of the LA1 archaeological site, produced a first right lower molar of a juvenile hominid (KNM-WT 42718). The relative small size of the crown, its marked MD elongation and BL reduction, the relative position of the cusps, the lack of a C6 and the mild expression of a protostylid, reinforced by metrical analyses, demonstrate the distinctiveness of this tooth compared with Australopithecus afarensis, A. anamensis, A. africanus and Paranthropus boisei, and its similarity to early Homo. The LA1alpha site lies 2.2 m above the Ekalalei Tuff which is slightly younger than Tuff F dated to 2.34+/-0.04 Myr. This juvenile specimen represents the oldest occurrence of the genus Homo in West Turkana.     

Therapeutic targeting of innate immunity with Toll-like receptor agonists and antagonists

The identification of the antigen recognition receptors for innate immunity, most notably the Toll-like receptors, has sparked great interest in therapeutic manipulation of the innate immune system. Toll-like receptor agonists are being developed for the treatment of cancer, allergies and viral infections, and as adjuvants for potent new vaccines to prevent or treat cancer and infectious diseases. As recognition grows of the role of inappropriate Toll-like receptor stimulation in inflammation and autoimmunity, significant efforts have begun to develop antagonists to Toll-like receptors as well.     

Serological survey of herpesvirus infections in wild ruminants of France and Belgium

The presence of antibodies against bovine herpesvirus 1 (BHV-1), bovid herpesvirus 6 (BHV-6), herpesvirus of Cervidae type 1 (HVC-1), reindeer herpesvirus, bovine herpesvirus 2 (BHV-2) and bovid herpesvirus 4 (BHV-4) was investigated in wild ruminants of France and Belgium between 1981 and 1986. There were no animals serologically positive for BHV-4. Antibodies against BHV-2 were demonstrated in roe deer (Cervus capreolus) (less than 1%) and chamois (Rupicapra rupicapra) (1%) in France. Animals seropositive to the four related viruses (BHV-1, BHV-6, HVC-1, reindeer herpesvirus) were detected in red deer (Cervus elaphus) in France and Belgium (1% and 11%, respectively), in roe deer (less than 1%) from France, in chamois (4%) in France and in ibex (Capra ibex) (4%) from France. The presence of antibodies against HVC-1, especially in red deer from Belgium, may suggest that wild ruminants in continental Europe are now infected with this virus, which previously has been isolated only in Scotland.     

Cutting edge: ectopic expression of the IL-12 receptor-beta 2 in developing and committed Th2 cells does not affect the production of IL-4 or induce the production of IFN-gamma

The IL-12 receptor-beta 2 (IL-12R beta 2) chain is expressed on Th1 cells and lost upon differentiation to the Th2 phenotype. This has been suggested as the basis for commitment of Th1 cells, because early differentiated Th2 cells do not reverse their phenotype and do not produce IFN-gamma on restimulation in the presence of IL-12. In this study, we ectopically expressed the IL-12 receptor-beta 2 (IL-12R beta 2) bicistronically with enhanced green fluorescent protein by retroviral infection in developing and committed Th2 cells. Restimulation of Th2 cells expressing this ectopic IL-12R beta 2 in the presence of IL-12 led to levels of IL-4 production similar to those in control Th2 cells. The expression of IL-12R beta 2 in Th2 cells did not lead to significant levels of IFN-gamma production, although IL-12-mediated STAT signaling and proliferation were restored. Thus, although the IL-12R beta 2 and IL-12-dependent STAT4 activation are required for Th1 responses, activation of this pathway is not sufficient to restore a Th1 phenotype in developing or committed Th2 cells.     

Contact Patterns in a High School: A Comparison between Data Collected Using Wearable Sensors,Contact Diaries and Friendship Surveys

Given their importance in shaping social networks and determining how information or transmissible diseases propagate in a population, interactions between individuals are the subject of many data collection efforts. To this aim, different methods are commonly used, ranging from diaries and surveys to decentralised infrastructures based on wearable sensors. These methods have each advantages and limitations but are rarely compared in a given setting. Moreover, as surveys targeting friendship relations might suffer less from memory biases than contact diaries, it is interesting to explore how actual contact patterns occurring in day-to-day life compare with friendship relations and with online social links. Here we make progresses in these directions by leveraging data collected in a French high school and concerning (i) face-to-face contacts measured by two concurrent methods, namely wearable sensors and contact diaries, (ii) self-reported friendship surveys, and (iii) online social links. We compare the resulting data sets and find that most short contacts are not reported in diaries while long contacts have a large reporting probability, and that the durations of contacts tend to be overestimated in the diaries. Moreover, measured contacts corresponding to reported friendship can have durations of any length but all long contacts do correspond to a reported friendship. On the contrary, online links that are not also reported in the friendship survey correspond to short face-to-face contacts, highlighting the difference of nature between reported friendships and online links. Diaries and surveys suffer moreover from a low sampling rate, as many students did not fill them, showing that the sensor-based platform had a higher acceptability. We also show that, despite the biases of diaries and surveys, the overall structure of the contact network, as quantified by the mixing patterns between classes, is correctly captured by both networks of self-reported contacts and of friendships, and we investigate the correlations between the number of neighbors of individuals in the three networks. Overall, diaries and surveys tend to yield a correct picture of the global structural organization of the contact network, albeit with much less links, and give access to a sort of backbone of the contact network corresponding to the strongest links, i.e., the contacts of longest cumulative durations.     

Close encounters in a pediatric ward: measuring face-to-face proximity and mixing patterns with wearable sensors

Background

Nosocomial infections place a substantial burden on health care systems and represent one of the major issues in current public health, requiring notable efforts for its prevention. Understanding the dynamics of infection transmission in a hospital setting is essential for tailoring interventions and predicting the spread among individuals. Mathematical models need to be informed with accurate data on contacts among individuals.

Methods and Findings

We used wearable active Radio-Frequency Identification Devices (RFID) to detect face-to-face contacts among individuals with a spatial resolution of about 1.5 meters, and a time resolution of 20 seconds. The study was conducted in a general pediatrics hospital ward, during a one-week period, and included 119 participants, with 51 health care workers, 37 patients, and 31 caregivers. Nearly 16,000 contacts were recorded during the study period, with a median of approximately 20 contacts per participants per day. Overall, 25% of the contacts involved a ward assistant, 23% a nurse, 22% a patient, 22% a caregiver, and 8% a physician. The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found. In the setting under study, caregivers do not represent a significant potential for infection spread to a large number of individuals, as their interactions mainly involve the corresponding patient. Nurses would deserve priority in prevention strategies due to their central role in the potential propagation paths of infections.

Conclusions

Our study shows the feasibility of accurate and reproducible measures of the pattern of contacts in a hospital setting. The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies. Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.