9 research outputs found

    Corvid Re-Caching without ‘Theory of Mind’: A Model

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    Scrub jays are thought to use many tactics to protect their caches. For instance, they predominantly bury food far away from conspecifics, and if they must cache while being watched, they often re-cache their worms later, once they are in private. Two explanations have been offered for such observations, and they are intensely debated. First, the birds may reason about their competitors' mental states, with a ‘theory of mind’; alternatively, they may apply behavioral rules learned in daily life. Although this second hypothesis is cognitively simpler, it does seem to require a different, ad-hoc behavioral rule for every caching and re-caching pattern exhibited by the birds. Our new theory avoids this drawback by explaining a large variety of patterns as side-effects of stress and the resulting memory errors. Inspired by experimental data, we assume that re-caching is not motivated by a deliberate effort to safeguard specific caches from theft, but by a general desire to cache more. This desire is brought on by stress, which is determined by the presence and dominance of onlookers, and by unsuccessful recovery attempts. We study this theory in two experiments similar to those done with real birds with a kind of ‘virtual bird’, whose behavior depends on a set of basic assumptions about corvid cognition, and a well-established model of human memory. Our results show that the ‘virtual bird’ acts as the real birds did; its re-caching reflects whether it has been watched, how dominant its onlooker was, and how close to that onlooker it has cached. This happens even though it cannot attribute mental states, and it has only a single behavioral rule assumed to be previously learned. Thus, our simulations indicate that corvid re-caching can be explained without sophisticated social cognition. Given our specific predictions, our theory can easily be tested empirically

    Heatmap showing percentage of patients with a travel history to Asia, divided by region (right axis) and recorded symptoms (left axis), who were tested for each arbovirus (horizontal axes) posing a risk on that continent (see Fig 1).

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    <p>The number of patients in each region-symptom combination follows each region in parentheses, far right. Groups in which a 100% of patients with a specific region-symptom combination were tested are depicted as black, with a sliding scale to white for groups in which 0% of patients were tested. Region-symptom combinations that are atypical for a certain arbovirus are depicted as diagonal lines.</p

    Adjusted odds ratios of statistically significant predictive syndromes for a positive test outcome.

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    <p>The test is stated in column 1, with corresponding variables in column 2. Variables were adjusted for age, sex, travel region, and diagnostic laboratory.</p

    Geographical distribution of medically important arboviruses that cause febrile disease in humans.

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    <p>All arboviruses cause febrile symptoms, but symptoms more specific to certain viruses are represented in three columns: 1) Arthralgia-Rash (AR); 2) Neurological symptoms (NS), and 3) Hemorrhagic symptoms (HS). Arboviruses not known to cause more than febrile symptoms are preceded with a §-sign. Arboviruses more likely to be diagnosed in travelers are followed by *. DENV^ is a serocomplex encompassing multiple dengue viruses that can cause similar clinical disease in humans. For viruses in gray type, diagnostics are unavailable in the Netherlands but in most cases can tested through the European Network for Imported Viral Diseases (ENVID). Geographical regions based on UN definitions of world regions. EU, Sub-Saharan Africa and South & Southeast Asia regions are grouped in these representations for visual clarity but are subdivided according to UN definitions for analysis as can been seen in Figs <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004073#pntd.0004073.g003" target="_blank">3</a>–<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0004073#pntd.0004073.g006" target="_blank">6</a>. AR = arthralgia-rash; NS = neurological symptoms; HS = hemorrhagic symptoms; AKHV = Alkhurma hemorrhagic fever virus; BANV = Banna virus; BFV = Barmah Forest virus; BWAV = Bwamba virus; BUNV = Bunyamwera virus; CEV = California encephalitis virus; CHIKV = Chikungunya virus; CTFV = Colorado tick fever virus; CCHFV = Crimean-Congo hemorrhagic fever; DENV = Dengue virus; EEEV = Eastern equine encephalitis virus; GROV = Guaroa virus; ILEV = Ilesha virus; ILHV = Ilheus virus; JEV = Japanese encephalitis virus; KFDV = Kyasanur Forest disease virus; LCV = La cross virus; LIV = Louping Ill virus; MAYV = Mayaro virus; MURV = Murray Valley virus; NRIV = Ngari virus; OHFV = Omsk hemorrhagic fever virus; ONNV = O’Nyong Nyong virus; OROV = Oropouche virus; RVFV = Rift Valley fever virus; ROCV = Rocio virus; RRV = Ross river virus; SFV = Sandfly fever (Naples / Sicilian / other); SFTS V = Severe Fever with Thrombocytopenia Syndrome Virus; SINV = Sindbis virus; SLEV = St. Louis encephalitis virus; TAHV = Tahyna virus; TATV = Tataguine virus; TBEV = Tick-borne encephalitis virus; TOSV = Toscana virus; VEEV = Venezuelan equine encephalitis virus; WEEV = Western equine encephalitis virus; WNV = West Nile virus; YFV = Yellow fever virus; ZIKV = Zika virus.</p

    Does vaginal reconstructive surgery with or without vaginal hysterectomy or trachelectomy improve sexual well being? A prospective follow-up study.

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    Contains fulltext : 51305.pdf (publisher's version ) (Closed access)OBJECTIVE: To compare sexual well being in women with pelvic organ prolapse before and after vaginal reconstructive surgery. METHODS: Sixty-seven women, mean age 61 (36-85) years, who underwent vaginal reconstructive surgery, were asked to complete detailed questionnaires before and after surgery. In addition, they underwent a physical examination using the Pelvic Organ Prolapse Quantification (POPQ), before surgery and at follow-up. RESULTS: Mean duration of follow-up was 14.4 months (6.6-27.6 months). The overall satisfaction with the operation was high with a mean of 7.5 on a visual analogue scale from 0 to 10. There was a significant improvement of dyspareunia after vaginal reconstructive surgery. The ability to have intercourse, the satisfaction with intercourse as well as the frequency of intercourse also improved although not significantly. Urine loss during intercourse improved significantly. CONCLUSION: Vaginal reconstructive surgery for pelvic organ prolapse has a positive effect on the sexual well being of the afflicted women
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