Defecation Rate Research Articles

Optimal control analysis of Taenia saginata bovine cysticercosis and human taeniasis

Bovine cysticercosis and human taeniasis are neglected food-borne diseases that pose challenge to food safety, human health and livelihood of rural livestock farmers. In this paper, we have formulated and analyzed a deterministic model for transmission dynamics and control of taeniasis and cysticercosis in humans and cattle respectively. The analysis shows that both the disease free equilibrium (DFE) and endemic equilibrium (EE) exist. To study the dynamics of the diseases, we derived the basic reproduction number R0 by next generation matrix method which shows whether the diseases die or persist in humans and cattle. The diseases clear if R0<1 and persist when R0>1. The normalized forward sensitivity index is used to derive sensitive indices of model parameters. Sensitivity analysis results indicate that human's and cattle's recruitment rates, infection rate of cattle from contaminated environment, probability of humans to acquire taeniasis due to consumption of infected meat, defecation rate of humans with taeniasis and the consumption rate of raw or undercooked infected meat are the most positive sensitive parameters whereas the natural death rates for humans, cattle, Taenia saginata eggs and the proportion of unconsumed infected meat are the most negative sensitive parameters in diseases’ transmission. These results suggest that control measures such as improving meat cooking, meat inspection and treatment of infected humans will be effective for controlling taeniasis and cysticercosis in humans and cattle respectively. The optimal control theory is applied by considering three time dependent controls which are improved meat cooking, vaccination of cattle, and treatment of humans with taeniasis when they are implemented in combination. The Pontryagin's maximum principle is adopted to find the necessary conditions for existence of the optimal controls. The Runge Kutta order four forward-backward sweep method is implemented in Matlab to solve the optimal control problem. The results indicate that a strategy which focuses on improving meat cooking and treatment of humans with taeniasis is the optimal strategy for diseases’ control.

Elephant Population Status, Distribution and Conservation Threats in Kibale National Park, Uganda

This study focused on the estimation of the African elephant population, distribution, and conservation threats in Kibale National Park (KNP) from August 2019 to February 2020. The objectives of the study were to: generate population estimates, distribution and assess threats to the conservation of elephants. The line transect method based on the dung pile count density from line transect, dung decay, and defecation rates were used to estimate the elephant population. The density was calculated by multiplying the decay rate with the ratio of dung density to defecation rates. The overall elephant population was estimated at 566.27 (95% Confidence limits 377.24-850.02). This was a slow increase from 393 recorded in 2005 to 566 animals in 2019. Elephants were widely distributed within the park and these pose challenges such as increasing human-elephant conflicts. With a steady increase in the elephant population and seasonal movements out of the park, there is a need to continuously monitor elephant population growth and ranging behaviour vis-a-vis available habitat range and how this impacts ecosystem dynamics and human-elephant conflicts

Patient-Reported Outcomes in the Acute Phase of the Randomized Hypofractionated Irradiation for Prostate Cancer (HYPRO) Trial

Many patients experience bowel and bladder toxicity during the acute phase of radiation therapy for prostate cancer. Recent literature indicates that hypofractionation (HF) might increase this acute response but little is known on patient-reported outcome during this phase with HF. We evaluated the course of patient-reported acute symptoms during HF versus standard fractionated (SF) radiation therapy within the hypofractionated irradiation for prostate cancer (HYPRO) trial. In the HYPRO trial patients were treated with either 64.4 Gy (HF) in 19 fractions (3 times per week) or 78 Gy (SF) in 39 fractions (5 times per week). Normalized total dose for 2 Gy/fractions (NTD2Gy)for acute toxicity (α/β ratio of 10) for HF was 72.1 Gy with a similar dose rate of 10.2 Gy per week. Among the 794 patients who were previously eligible for acute grade ≥2 toxicity assessment, 717 had filled out ≥1 symptom questionnaires. For each maximum symptom, we scored "any complaint" and "moderate-severe complaint." Differences were tested by χ2 test, and associations with clinical factors were tested using logistic regression. Significance was set at P ≤ .008 to adjust for multiple testing. We observed significantly higher rates of moderate-severe painful defecation (HF 10.8%, SF 5.3%), any mucus discharge (HF 47.1%, SF 37.4%), any rectal blood loss (HF 16.1%, SF 9.3%), increased daily stool frequency ≥4 and ≥6 (HF 34.6%/13.8%, SF 25.6%/7.0%), and any urinary straining (HF 69.9%, SF 58.0%). At 3 months postradiation therapy, rates dropped considerably with similar levels for HF and SF. Hormonal treatment was associated with less acute gastrointestinal symptoms. The increased patient-reported acute rectal symptoms with HF confirmed the previously reported results on acute grade ≥2 rectal toxicity. The increase in bladder symptoms with HF was not identified previously. These observations contradict the NTD2Gy calculations. We observed no patterns of persisting complaints with HF after the acute period; therefore, HF is well tolerated and only associated with a temporary increase of symptoms.

Defecation rates of white-tailed deer (Odocoileus virginianus) based on fiber content in feces

Objective: To develop three models in order to estimate the defecation rate ofwhite-tailed deer (Odocoileus virginianus) according to the season of the year,content of neutral detergent fiber (NDF), and acid detergent fiber (ADF) in feces.Design / methodology / approach: Nine captive adult deer were assigned tothree levels of dietary fiber. Fecal groups (defecation rate) were counted, forageconsumption was estimated, and feces were analyzed for NDF and ADF content. Arandomized block design was used, where the effect of the treatments was blockedby season, and a multiple regression analysis was used to define the predictionmodels of the defecation rates.Results: The rates were different for dietary fiber levels (p&amp;lt;0.0001), and for theyear season (p = 0.0007). For spring, the defecation rate model (DR) was DR = -4.84696 - [0.02159 (NDF)] + [0.58397 (ADF)]; for summer DR = -51.0272 +[0.26868 (NDF)] + [1.61121 (ADF)]; and for winter DR = 7.82939- [0.02667 (NDF)]+ [0.17309 (ADF)].Limitations / implications: Defecation rate or fecal group counting is a useful toolto estimate deer populations. Nevertheless, the definition of an adequatedefecation rate represents a hard task, since it depends on various factors such asthe environmental conditions, and the components of the diet the deer consumes.Findings / conclusions: The defecation rate varies depending on the year seasonand the fiber content in the diet.

COVID 19 pandemic and behavioural change toward water hygiene and sanitation (WASH): A study in rural Odisha, India

COVID-19 Pandemic is not the first-ever pandemic which hit this globe, but it is the deadliest and possesses enough capability to shake the so-called developed global system. Additionally, the SARS-CoV-2 virus has been detected in feces of infected individuals, leading to the possibility that fecal-oral transmission could also play a role in virus transmission, particularly in low- and middle-income countries (LMICs) with high rates of open defecation, ineffective fecal sludge management, and poor access to safe drinking water. So people’s behaviour towards WASH is very important at this time.This study was done in two rural districts of Odisha, i.e. Sambalpur and Mayurbhanj. The district, blocks, villages were selected with simple random sampling. A sample size of 50 was taken through telephonic interviews.This study was done to understand the real life scenario of rural Odisha and how COVID 19 pandemic shape their behaviour toward the water hygiene and sanitation. So the research was designed in such a manner so that it can capture the important dimensions of WASH. The sample size includes a non-homogeneous group which represents the rural population in terms of social, economic, educational and gender perspectives. During the S1 situation if the source of drinking water is taken into consideration people were using those sources from many years and after lot of efforts from the government side people never changed their behaviour, people’s perspective on water treatment and hand washing were so strong that there was 32 percent people who never used to wash their hands they don’t even think it was important (38% people. At least 34 percent people used to thought there was no need of treating water before drinking when 46 percent of the sample population was using the open water source. But these scenarios changed after they lose their hope on their own immunity during the S2 situation. The numbers of washing hands increase, people started using soap and the perspective towards the water treatment also changed towards a positive aspect.This study clearly finds that 3As (Availability, Accessibility and Affordability) is not enough for behavioural change towards WASH but it needs 4As (Availability, Accessibility, Affordability and Accountability) and 1I (Intension). Because until people understand that they are accountable for their own vulnerability they will not able to think about the behavioural change and without their intension they cannot start the process.

Big bees spread disease: body size mediates transmission of a bumble bee pathogen.

Trait variation can have important consequences for the outcomes of species interactions. Even though some traits vary as much within species as across related species, models and empirical studies typically do not consider the role of intraspecific trait variation for processes such as disease transmission. For example, many pollinator species are in decline because of a variety of stressors including pathogens, but the role of intraspecific trait variation in mediating disease dynamics is rarely considered. For example, pollinator body size could affect pathogen transmission via differences in resistance, foraging behavior and physiology. We tested effects of body size on pollinator pathogen transmission using the common eastern bumble bee Bombus impatiens in field tents, introducing an infected "donor" microcolony of large or small workers with an uninfected average-sized "recipient" microcolony and allowing bees to forage for 9-16d. Small donor bees had nearly 50% higher infection intensity (cells/0.02 μL) than large donor bees, but large donor bees were twice as likely to transmit Crithidia bombi to recipient bees. Both behavioral and physiological mechanisms may underlie this apparent paradox. Compared to small bees, large bees foraged more and produced more feces; simulations showed that foraging and defecation rates together had stronger effects on transmission than did donor infection intensity. Thus, effects of bee size on contact rates and pathogen supply may play significant roles in disease transmission, demonstrating the multifaceted impacts of traits on transmission dynamics.

Modeling and analysis of taeniasis and cysticercosis transmission dynamics in humans, pigs and cattle

Taeniasis and cysticercosis pose a significant challenge to food safety and public health. Cysticercosis reduces the market value for pigs and cattle by making pork and beef unsafe for consumption. In this paper, a mathematical model for the transmission dynamics of taeniasis and cysticercosis in humans, pigs and cattle is formulated and analyzed. The analysis shows that both the disease free equilibrium (DFE) and the endemic equilibrium (EE) exist. To study the dynamics of the diseases, we derived the basic reproduction number R_{0} by next generation matrix method. When R_{0}< 1, the DFE is globally asymptotically stable whereas when R_{0} > 1 the EE is globally asymptotically stable. The normalized forward sensitivity index was used to determine sensitive parameters to the diseases. Humans’ recruitment rate, probability of humans’ infection with taeniasis and the defecation rate of taenia eggs by humans with taeniasis are the most positive sensitive parameters to diseases’ transmission whereas the human natural death rate is the most negative sensitive parameter. However, it is biologically unethical and not practical to increase human natural mortality rate for disease control. In this case, other parameters with negative sensitivity indices such as death rate of taenia eggs and proportions of unconsumed infected beef and pork can be considered for disease control. Generally, to control the diseases, more efforts should be made directed to reducing the number of humans who have taeniasis and defecate in the open environment. Also meat inspection and indoor keeping of cattle and pigs should be emphasized.

The Importance of Objective Stool Classification in Fecal 1H-NMR Metabolomics: Exponential Increase in Stool Crosslinking Is Mirrored in Systemic Inflammation and Associated to Fecal Acetate and Methionine.

Past studies strongly connected stool consistency—as measured by Bristol Stool Scale (BSS)—with microbial gene richness and intestinal inflammation, colonic transit time and metabolome characteristics that are of clinical relevance in numerous gastro intestinal conditions. While retention time, defecation rate, BSS but not water activity have been shown to account for BSS-associated inflammatory effects, the potential correlation with the strength of a gel in the context of intestinal forces, abrasion, mucus imprinting, fecal pore clogging remains unexplored as a shaping factor for intestinal inflammation and has yet to be determined. Our study introduced a minimal pressure approach (MP) by probe indentation as measure of stool material crosslinking in fecal samples. Results reported here were obtained from 170 samples collected in two independent projects, including males and females, covering a wide span of moisture contents and BSS. MP values increased exponentially with increasing consistency (i.e., lower BSS) and enabled stratification of samples exhibiting mixed BSS classes. A trade-off between lowest MP and highest dry matter content delineated the span of intermediate healthy density of gel crosslinks. The crossectional transects identified fecal surface layers with exceptionally high MP and of <5 mm thickness followed by internal structures with an order of magnitude lower MP, characteristic of healthy stool consistency. The MP and BSS values reported in this study were coupled to reanalysis of the PlanHab data and fecal 1H-NMR metabolomes reported before. The exponential association between stool consistency and MP determined in this study was mirrored in the elevated intestinal and also systemic inflammation and other detrimental physiological deconditioning effects observed in the PlanHab participants reported before. The MP approach described in this study can be used to better understand fecal hardness and its relationships to human health as it provides a simple, fine scale and objective stool classification approach for the characterization of the exact sampling locations in future microbiome and metabolome studies.

The effect of lizards on the dispersal and germination of Capparis spinosa (Capparaceae).

Seed dispersal is a key component of the interactions between plants and animals. There is little research on the effects of lizard seed dispersal, which is more common on islands than elsewhere. In this study, the effects of the passage of Capparis spinosa seeds through Teratoscincus roborowskii lizard digestive tracts on the seed coats, water uptake rates and germination rates were investigated. In addition, the spatial patterns of fecal deposition by lizards in various microhabitats were assessed. Our results showed that the mean retention time (MRT) of mealworms was significantly longer than that of C. spinosa seeds in both adult and juvenile lizards. The defecation rate of C. spinosa tended to be lower than that of mealworms, which might be beneficial for seed dispersal. It was determined that the longer MRT of C. spinosa seeds enhanced the permeability of the seed coats, which promoted fast water uptake, broke seed dormancy and increased the seed germination rate. Furthermore, the seeds that passed through the digestive tracts of lizards were deposited in favorable germination microhabitats. By enhancing seed germination and depositing intact and viable seeds in safe potential recruitment sites, the lizard T. roborowskii acts, at least qualitatively, as an effective disperser of C. spinosa.

Body mass explains digestive traits in small vespertilionid bats.

Bats are unique among mammals in that they have evolved the capacity to fly. This has generated strong selective pressure on the morphology and function of their digestive system. Given that in bats intestinal length and nominal surface-area are proportional to body mass, this trait importantly relates to explaining some of their digestive characteristics. We described the relationship between digestive traits and body mass of four species of bats of the family Vespertilionidae living in a montane ecosystem in central Mexico. We calculated food transit time, apparent dry matter digestibility, and defecation rate in feeding trials under captive conditions. We also: (1) built a model of the relationship between digestive traits and body mass to determine if this association was consistent within the members of the family Vespertilionidae, and (2) mapped these traits along the phylogeny to explore how digestive characteristics may have evolved. In our feeding trials, body mass was positively related to transit time and negatively related to apparent dry matter digestibility. The model predicted accurately the transit time in bats with body mass < 20g. The phylogenetic approach suggested that over the evolutionary history of the family, transit time decreased as digestibility increased. Because of the results obtained here, it is likely that for most bats of the family Vespertilionidae, adaptations in digestive traits to process food have followed evolutionary changes in their body mass. We discuss these findings in a physiological and ecological context.

Хімічна меліорація кислих ґрунтів з відтворенням і регулюванням їх родючості за біологізації систем удобрення в умовах Лісостепу України

Goal. To study the influence of advanced technologies of defecation on the dynamics of fertility, physicochemical and agrochemical properties of gray forest slightly acidic soil and slightly acidic leached chernozem, the productivity of sugar beets at biologization of fertilizer systems in the Right Bank and Central Forest-Steppe of Ukraine. Methods. Physicochemical and agrochemical analyzes of soil, phenological observations of plant growth and development were carried out. Results. 1.5 dose of CaCO3 calculated according to Ng (9.0 and 7.5 t/ha in physical weight) was determined to be the most effective for the soil-harvesting complex of gray forest weakly acidic soil and typical leached weakly acidic chernozem. The maximum neutralization of soil acidity was achieved: the pH of the soil solution increased to 7.2 and 6.9, the hydrolytic acidity of soils decreased to 0.42 and 1.0 cmole/kg of soil with an increase in the number of absorbed bases to 25.7 and 28, 5 cmole/kg of soil and the degree of saturation of the bases up to 95.3 and 97.0%. The most effective rate of defecation in terms of the impact on the content of basic nutrients in the gray forest slightly acidic soil and slightly acidic leached chernozem was 1.5 dose of CaCO3 calculated according to Ng (9.0 and 7.5 t/ha in physical weight). In such conditions, the maximum alkaline hydrolyzed nitrogen content was reached — 207.3 and 140.5, as well as the content of mobile phosphorus — 357.7 and 172.4, potassium exchange — 198.4 and 106.4 mg/kg of soil, respectively. The productivity of sugar beets increased to 52.7 and 67.7 t/ha with sugar harvest — 10.3 and 12.0 t/ha, respectively. Conclusions. The application of defecates on weakly acidic gray forest soil and weakly acidic leached chernozem with improved methods and technologies of application of sugar beet fertilization systems for biologization contributed to the improvement of physicochemical and agrochemical properties of soils while maintaining their fertility and productivity.

Tasa de defecación del Temazate rojo (&lt;i&gt;Mazama temama&lt;/i&gt;) en cautiverio

El temazate rojo (Mazama temama) es uno de los cérvidos más abundantes y con más amplia distribución en los bosques neotropicales. Un método para estimar densidades poblacionales es mediante el conteo de heces, para lo cual es necesario conocer la tasa de defecación. Para obtener dicha tasa en este ungulado, se realizaron conteos de los eventos de defecación, durante cuatro días, en tres individuos adultos: dos hembras y un macho; alojados en cautiverio en el parque Xcaret, ubicado en el estado de Quintana Roo, México. La tasa de defecación promedio obtenida fue de 10 ± 3,33 (DE) grupos de excrementos/individuo/día. Este dato permitirá realizar estimaciones de densidad poblacional de esta especie en vida libre.

Effect of Juice Extract of Beetroot, Lemon, Pawpaw Leaf and Their Combinations on Weight and Lipid Profile of Albino Wistar Rat

Fruits and vegetables have been found to contain important phytochemicals that have been implicated in preventing overweight and obesity. This study is aim at investigating the effects of lemon, pawpaw leaves, beetroots juices and their combinations on rates of urination, defecation, and weight changes of albino wistar rats were examine at interval. Also, the effects of the juice extracts on cholesterol, triglyceride, high density lipoprotein and low density lipoprotein where examined. Juice was extracted using a laboratory extractor. Results obtained indicates an increase in weight in groups A, B, C, D, E, F and G. But a decrease in weight was noticed in group H, which is the group administered all juice extracts at equal proportion. A reduction in the volume of urine was noticed in group A, B, C, D, F, G and H. Urine level was seen to increase in group E. The quantity of feces was observed to reduce in groups A, E, F, G and H. with the exception of groups B,C and D where the feces level was seen to increase. Cholesterol level was observed to reduce drastically in group D compared with other groups. Triglyceride level was observed to be low in group B compared with other groups. HDL level was very low in group H compared to other groups. LDL level was very low in group D compared with other groups. Group D also had a very high effect on HDL and LDL by increasing and reducing HDL and LDL respectively. This is only second to control group. The above evidences suggests that some fruit juices directly inhibits weight gain by providing the needed calories required by the body for its activity. This implies that consumption has a potential role in the prevention of overweight and obesity.

Toxicity effects of Cubic Cu2O nanoparticles on defecation rate and length in C. Elegans

Introduction: The increased presence of radiation and toxins in the atmosphere has given rise to fuel cells and nanoparticle technology with the ability to catalyze reactions at favorable energy levels. The purpose of this experiment was to determine the lasting effects of a synthesized catalyst on a model organism, Caenorhabditis (C.) elegans.&#x0D; Methods: Copper sulfate was tested alongside copper(I) oxide (i.e. Cu2O) to dissociate the copper composition effects from those of the nanoparticles themselves. The prospect of testing both defecation rate and size differences allowed for C. elegans to be utilized due to their low maintenance costs, mapped neuronal pathways, and short-generation times.&#x0D; Results: The results indicated significant toxicity effects in wild-type worms as witnessed by the decreases in nematode defecation rate and length by copper sulfate, with similar results in SMF-1 and PCS-1 mutants by Cu2O catalysts in cubic synthesized form.&#x0D; Conclusion: These outcomes reinforce the known effects of metal oxides on pollutants and highlight the need for further testing with additional variables such as varying pH and temperature.

Stunting in childhood: an overview of global burden, trends, determinants, and drivers of decline

ABSTRACTBackgroundProgress has been made worldwide in reducing chronic undernutrition and rates of linear growth stunting in children under 5 y of age, although rates still remain high in many regions. Policies, programs, and interventions supporting maternal and child health and nutrition have the potential to improve child growth and development.ObjectiveThis article synthesizes the available global evidence on the drivers of national declines in stunting prevalence and compares the relative effect of major drivers of stunting decline between countries.MethodsWe conducted a systematic review of published peer-reviewed and gray literature analyzing the relation between changes in key determinants of child linear growth and contemporaneous changes in linear growth outcomes over time.ResultsAmong the basic determinants of stunting assessed within regression-decomposition analyses, improvement in asset index score was a consistent and strong driver of improved linear growth outcomes. Increased parental education was also a strong predictor of improved child growth. Of the underlying determinants of stunting, reduced rates of open defecation, improved sanitation infrastructure, and improved access to key maternal health services, including optimal antenatal care and delivery in a health facility or with a skilled birth attendant, all accounted for substantially improved child growth, although the magnitude of variation explained by each differed substantially between countries. At the immediate level, changes in several maternal characteristics predicted modest stunting reductions, including parity, interpregnancy interval, and maternal height.ConclusionsUnique sets of stunting determinants predicted stunting reduction within countries that have reduced stunting. Several common drivers emerge at the basic, underlying, and immediate levels, including improvements in maternal and paternal education, household socioeconomic status, sanitation conditions, maternal health services access, and family planning. Further data collection and in-depth mixed-methods research are required to strengthen recommendations for those countries where the stunting burden remains unacceptably high.

Fecal-Oral Transmission of COVID-19 in India

Although the spread of COVID-19 through droplets, surface contact and aerosolized transmission has been well-publicized, the fecal-oral route is yet another identified method of transmission. According to a meta-analysis by the New England Journal of Medicine, it was found that fecal viral shedding continues throughout the disease, even after nasopharyngeal tests appear negative. Moreover, gastrointestinal symptoms seem to be common for COVID-19 patients, with a prevalence of approximately 18%.[1,2] It was also found that patients with digestive symptoms experience significantly longer hospital stays.[3] As India’s number of COVID-19 cases continues to increase, concerns about fecal-oral transmission are being raised in a country that has the highest open defecation rates in the world, where approximately 620 million people defecate in the open. It is a problem that comes with severe public health consequences, including diarrhea, high child mortality, spread of diseases, malnutrition and stunting of growth.[4] Public health officials should be concerned about how this will affect India’s transmission of COVID-19. Read more.....

Incorporating the sampling effectiveness of detection dogs in the faecal standing crop method

Evaluating the population status of elusive and rare species is a challenge for wildlife managers and conservationists. A promising method that has been used is faecal pellet counting applied to the faecal standing crop (FSC) method. The FSC method estimates population density based on faecal pellets counted in a given area by using parameters such as defecation rate and faecal persistence, which vary according to the environment. The search for faeces has become more effective with the help of scat detection dogs, which have a better detection rate compared to humans. Therefore, we aimed to incorporate the sampling effectiveness of scat detection dogs as parameters in FSC methods. For this purpose, two experiments were conducted to evaluate the detectability of Mazama faeces related to their distance from a search transect and their age (time since deposition). Our results show that incorporating scat detection dog parameters can result in density estimates three times higher than those reached without incorporating the detection dog parameters in FSC methods.

Estimating wild boar density and rooting activity in a Mediterranean protected area

The mitigation of ecological/economic impacts of wild boar Sus scrofa is one of the most challenging issues in wildlife management worldwide. Monitoring population density and impact of wild boar is crucial to plan appropriate management actions to reduce its density, environmental impact and epidemiological risk, as well as to evaluate control effectiveness. In 2018–2019, we used plot-based faeces counts, coupled with specific estimates of daily defecation rates, to estimate wild boar density and rooting activity in natural/semi-natural habitats, in a Mediterranean protected area. Daily defecation rate was 6.7 faeces/individual, much lower than that of ruminants. We obtained estimates of 70.0–70.5 faeces/km2, corresponding to wild boar densities of c. 10.5 individuals/km2 (relative standard error: 18%) in both years. Low daily defecation rates and skewed distribution frequencies of wild boar faeces should be considered to plan surveys with an adequate sampling design and intensity. Faeces abundance and rooting activity peaked in ecotones, i.e. open areas at the interface of wood patches, whereas they did not differ between other habitat types, suggesting a fine-scale concordance between the two indicators. Long-term monitoring is needed to assess relationships between indicators of impact and abundance at a broad scale. Our work shows how to undertake simultaneously wild boar density estimates and impact assessment in natural environments, which is particularly important for protected areas and/or habitats of conservation concern across the globally distributed Mediterranean biome.

Thermophilic response post feeding in Pleurodema nebulosum (Anura: Leptodactylidae) from Monte desert, Argentina.

We studied the thermophilic response to feeding of a typical desert adapted anuran from the Monte Desert. Our aim was to evaluate thermal changes in the selected body temperature of adult frogs of Pleurodema nebulosum, and measure the intestinal passage time, and food digestion. Our results show that after feeding, they selected higher micro-environmental temperatures ~ + 2°C than frogs that remained starved. Pleurodema nebulosum would present a postprandial thermophilic response. The time of retention of food in the digestive tract was thermo-dependent, being lower in those individuals who were incubated at high temperatures (25°C) compared to those subjected to lower temperatures (20°C). Although we did not detect effects of temperature on digestive efficiency, the mass of faecal material indicates an increase at temperatures closer to the selected ones, suggesting that the defecation rate is influenced by temperature. Laiuoperinae frogs are characterized by explosive breeding behavior and fast growing rate. The digestive efficiency is essential for acquiring energy necessary for growth, reproduction and refuge-seeking, among others. In this framework, the differential selection of temperatures between moments of fasting and feeding allows the frogs to maintain a high digestive efficiency, maximizing the absorption of nutrients.

Not so sluggish: movement and sediment turnover of the world’s heaviest holothuroid, Thelenota anax

Ecology of many sea cucumbers, including the world’s heaviest holothuroid Thelenota anax, remains understudied, hindering effective fisheries management and conservation. We located, measured and weighed 38 T. anax over 10 days at Lizard Island, northeast Australia. Body length alone was a suitable predictor of body weight for this species. Short-term (1–4 h) rates of displacement and sediment defecation were measured on 30 animals across three sites. The animals were highly mobile, moving, on average, 57 cm h−1 (± 11 SE), and reworking 34 g dry weight of sediment h−1 (± 7 SE). The animals moved more and defecated more sediments in areas where surrounding sediments had lower levels of organic matter. Defecation rates increased through daytime hours. The high mobility of T. anax should confer an advantage for mate-finding but also could increase spillover from small marine reserves into fishing grounds. Our findings galvanise a pattern of high mobility in larger holothuroids and show that food resources and time of day modulate the extent of sediment reworking by deposit feeding holothuroids. The high sediment turnover rate highlights the detrimental effect that overfishing of these large holothuroids will have on the health of coastal marine ecosystems.