For this study, we examined a large sample of museum specimens to ascertain the reproductive ecology of Rhinophrynus dorsalis (Mexican Burrowing Toad) in México. Seasonal aboveground activity was ...highest during May to August, which tracks monthly rainfall patterns across the region. Contrary to previous assertions, mean body sizes were similar between males and females but females attained larger maximum sizes. Male testis size was largest in May, tadpoles appeared in June, and juveniles were present in July, indicating that most breeding begins in May following the first heavy rains of the year. Few specimens possessed food in their stomachs suggesting that aboveground activity may be more devoted to reproduction than to foraging. The timing of reproduction was variable because most gravid females were encountered during May to August, but some were also present in October and January. Clutch size was estimated to range from 630 to 7,700 eggs, which was positively correlated with female body size. Size to sexual maturity in both males and females was reached in 8–9 mo after metamorphosis and at much smaller minimum and average sizes than previously reported. Adult body size was negatively related to latitude, such that the largest specimens were from the most southern latitudes, especially for males. The reproductive ecology of R. dorsalis resembles distantly related burrowing anurans more so than their close aquatic relatives in Pipidae.
Snake fungal disease (SFD) is a clinical syndrome associated with dermatitis, myositis, osteomyelitis, and pneumonia in several species of free-ranging snakes in the US. The causative agent has been ...suggested as Ophidiomyces ophiodiicola, but other agents may contribute to the syndrome and the pathogenesis is not understood. To understand the role of O. ophiodiicola in SFD, a cottonmouth snake model of SFD was designed. Five cottonmouths (Agkistrodon piscivorous) were experimentally challenged by nasolabial pit inoculation with a pure culture of O. ophiodiicola. Development of skin lesions or facial swelling at the site of inoculation was observed in all snakes. Twice weekly swabs of the inoculation site revealed variable presence of O. ophiodiicola DNA by qPCR in all five inoculated snakes for 3 to 58 days post-inoculation; nasolabial flushes were not a useful sampling method for detection. Inoculated snakes had a 40% mortality rate. All inoculated snakes had microscopic lesions unilaterally on the side of the swabbed nasolabial pit, including erosions to ulcerations and heterophilic dermatitis. All signs were consistent with SFD; however, the severity of lesions varied in individual snakes, and fungal hyphae were only observed in 3 of 5 inoculated snakes. These three snakes correlated with post-mortem tissue qPCR evidence of O. ophiodiicola. The findings of this study conclude that O. ophiodiicola inoculation in a cottonmouth snake model leads to disease similar to SFD, although lesion severity and the fungal load are quite variable within the model. Future studies may utilize this model to further understand the pathogenesis of this disease and develop management strategies that mitigate disease effects, but investigation of other models with less variability may be warranted.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Disease events are threatening wildlife populations across North America. Specifically, mortality events due to Ophidiomyces (snake fungal disease; SFD) have been observed recently in snakes in ...Illinois, US. We investigated the health of a population of eastern massasaugas (Sistrurus catenatus) in south-central Illinois using 1) a meta-analysis of hematologic findings from 2004, 2011, 2013, and 2014; 2) a determination of the prevalence of SFD in snakes examined in 2013 and 2014; and 3) the examination of 184 museum specimens collected from 1999–2013 for signs and presence of SFD. For the meta-analysis and prevalence of SFD, hematologic analytes were reduced to three principle components that explained 67.5% of the cumulative variance. There were significant differences among one principle component (total white blood cell counts, monocytes, lymphocytes, and basophils) across years when it was highest in 2004 and 2014. The top general linear model explaining the difference in principle components included the main effects of year and stage, body condition index (BCI), and the interaction between stage and BCI. The prevalence of SFD was 18% (n=7) in 2013 and 24% (n=11) in 2014, and no hematologic analytes were associated with SFD. In museum specimens, Ophidiomyces DNA was first detected from an individual collected in 2000. Studies such as these, integrating multiple modalities of health, can elucidate the epidemiology of diseases that may pose conservation threats.
•We explore how households insure themselves against consumption volatility.•We asked households how they would fund an expense equal to one month's income.•Consumption insurance mechanisms include ...borrowing from social networks.•More than one fifth of households have no plan to insure their consumption.•The likelihood of non-insurance increases with poor financial literacy.
We explore empirically how households insure themselves against consumption volatility. We asked households how they would fund an unexpected emergency consumption expense equivalent to one month's income. Answers reveal a range of consumption insurance mechanisms, including borrowing from credit markets and social networks. Despite this, more than one fifth of households have no plan to insure their consumption. The likelihood of non-insurance increases with poor financial literacy and is highest among households most at risk of experiencing a financial shock. Among these households we see large effects of poor financial literacy on non-insurance.
With the current rate of declines in global biodiversity, it is apparent that wildlife diseases are serving as additional threats to population declines and potentially species extinctions. ...Free-ranging Eastern Massasaugas (Sistrurus catenatus catenatus) have been reported susceptible to numerous health threats, one of which is a fatal fungal dermatitis. In response to the occurrence of the fungal dermatitis, a health survey and disease investigation was conducted on Eastern Massasaugas near Carlyle, Illinois in 2011. We captured 38 Eastern Massasaugas from March to April 2011. Polymerase chain reaction assays were performed from swabs collected from the faces of 34 snakes. We obtained hematologic data for 31 individuals, plasma biochemical data for 24, and toxicological data for 18. There was no evidence of Chrysosporium in any of the samples. Hematologic and plasma biochemistry parameters were consistent with previous health studies in the Carlyle population. Elemental toxicologic investigation of the plasma indicated variable levels of lead, copper, selenium, strontium, tin, iron, and zinc.
Aristotle characterized the elephant as "the beast which passeth all others in wit and mind" and the animal has long figured in cultural artifacts, even on continents it has never inhabited. Now ...Elephant provides an engaging look at the elephant's long le.
The Bigeye Chub (Hybopsis amblops) was once prevalent in the streams and rivers of Eastern and South Central Illinois. Populations of this species dwindled throughout Illinois in the middle of the ...20th century, to the point that the species was thought to be extirpated from the state (Smith 1979; Warren, Burr 1988). Recent sampling within Eastern and South Central Illinois have found reemerging populations of H. amblops across multiple basins. An intensive survey of the Vermilion River (Wabash River Drainage) in 2011 showed multiple year classes present and suggests that a healthy population of H. amblops is present in this basin. Additionally, a historic species distribution model was created to estimate the possible historic range of this species in Illinois. This model suggests that the possible historic range of H. amblops in Illinois included the entirety of the Vermilion, Little Vermilion, and Brouillets Creek basins as well as the northern parts of the Kaskaskia, Embarras, and Little Wabash River basins.
Navigational driving systems have used traditional track-up map displays for guiding immediate turn-by-turn decisions and traditional north-up map displays for facilitating navigational planning and ...learning about environmental layout (configural spatial knowledge), because no single map display has been usable for both purposes. Rizzardo and Colle (2013) showed that north-up map displays could successfully guide turn decisions when a new spatial plus verbal advisory turn indicator was used, raising the possibility of designing single map displays that also are usable for spatial learning. Multimedia instructional design models, modified for spatial learning from navigation and driving, identified the sources of extraneous cognitive load that limit spatial learning from moving maps. Predictions include that participants can learn more from north-up map displays with the new advisory indicator than the traditional indicator. Experiment 1 showed that after college students (N = 96) drove through a virtual city guided by 1 of 3 map types or voice commands, most configural spatial knowledge was acquired using the new north-up display, then the traditional north-up map display, and the least with the traditional track-up map display. In Experiment 2, college students (N = 192) watched the same map sequences from either the new north-up or the track-up map display, but with a limited duration of their glances to the map display (no driving). Viewing spatial plus verbal north-up map displays produced significant spatial learning even with short glance durations, but not when viewing track-up displays even with long glance durations. Theoretical and design implications are discussed.
Snake fungal disease (SFD) is a clinical syndrome associated with dermatitis, myositis, osteomyelitis, and pneumonia in several species of free-ranging snakes in the US. The causative agent has been ...suggested as Ophidiomyces ophiodiicola, but other agents may contribute to the syndrome and the pathogenesis is not understood. To understand the role of O. ophiodiicola in SFD, a cottonmouth snake model of SFD was designed. Five cottonmouths (Agkistrodon piscivorous) were experimentally challenged by nasolabial pit inoculation with a pure culture of O. ophiodiicola. Development of skin lesions or facial swelling at the site of inoculation was observed in all snakes. Twice weekly swabs of the inoculation site revealed variable presence of O. ophiodiicola DNA by qPCR in all five inoculated snakes for 3 to 58 days post-inoculation; nasolabial flushes were not a useful sampling method for detection. Inoculated snakes had a 40% mortality rate. All inoculated snakes had microscopic lesions unilaterally on the side of the swabbed nasolabial pit, including erosions to ulcerations and heterophilic dermatitis. All signs were consistent with SFD; however, the severity of lesions varied in individual snakes, and fungal hyphae were only observed in 3 of 5 inoculated snakes. These three snakes correlated with post-mortem tissue qPCR evidence of O. ophiodiicola. The findings of this study conclude that O. ophiodiicola inoculation in a cottonmouth snake model leads to disease similar to SFD, although lesion severity and the fungal load are quite variable within the model. Future studies may utilize this model to further understand the pathogenesis of this disease and develop management strategies that mitigate disease effects, but investigation of other models with less variability may be warranted.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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