Scavenging Behavior Research Articles

Prediction of coccidiosis prevalence in extensive backyard chickens in countries and regions of the Horn of Africa

Coccidiosis is one of the leading morbidity causes in chickens, causing a reduction of body weight and egg production. Backyard chickens are at risk of developing clinical and subclinical coccidiosis due to outdoor housing and scavenging behaviour, jeopardizing food security in households. The objectives of this study were to estimate clinical prevalence of coccidiosis at country and regional levels in the Horn of Africa in extensive backyard chickens. A binomial random effects model was developed to impute prevalence of coccidiosis. Previously gathered prevalence data (n = 40) in backyard chickens was used to define the model. Precipitation (OR: 1.09 (95% CI: 1.05–1.13) and the presence of seasonal rainfall (OR: 1.85, 95% CI: 1.27–2.70) significantly increase prevalence. Results showed an overall prevalence of coccidiosis in the Horn of Africa of 0.21 (95% CI: 0.15–0.29). Ethiopia, the Republic of South Sudan and Kenya showed the highest prevalence and Djibouti the lowest. Significant differences between Djibouti and the countries with highest prevalence were found. However, no evidence of a significant difference between the rest of the countries. Kenya and Ethiopia showed larger prevalence differences between regions. Results could assist with the targeting of testing for coccidiosis, the observation for clinical disease of chickens living in specific regions and as a baseline for the evaluation of future control measures.

Carcass provisioning and intra-guild risk avoidance between two sympatric large carnivores

Apex carnivores that rely primarily on predation play a central but complex role within scavenging ecology by potentially suppressing intra-guild competitors, but also facilitating them by providing a reliable supply of carrion. We investigated the competitive relationship between sympatric wolves (Canis lupus) and wolverines (Gulo gulo) in Norway across three seasons. We deployed remote cameras at fresh wolf kills (n = 29) and built Bayesian generalized linear mixed models (GLMMs) to explore the use of fresh wolf-killed prey by sympatric wolves and wolverines. Our results showed that wolves facilitated wolverines by providing scavenging opportunities. Biomass available from wolf kills was influenced by seasonal wolf prey preference and group size. Wolverines visited 100% of wolf kills in fall and winter, whereas only 18% in summer. We found that in winter, wolverines visited wolf kills 3.6 and 6.7 times more often than single wolves and wolf groups revisited their kills, and spent 10 and 25 times as much time at carcasses compared to single wolves and groups of wolves. Thus, wolverines played an important role in the depletion of wolf-killed prey, with potential effects on the scavenging behavior of other guild members. Understanding how globally threatened top predators may function as key species in scavenging processes is important to conservation as this may have community-wide cascading effects and support important ecosystem functions and services.Significance statementLarge carnivores serve a central role within scavenging ecology through the suppression and facilitation of intraguild competitors. The wolf, as an apex obligate predator, can provide a reliable supply of carrion, that can serve as an important resource to facultative scavengers. However, while facultative behavior helps to mitigate the effects of limited prey for scavengers, it can also increase exposure to competition and intraguild predation. Across three seasons, we explored the use of fresh wolf-killed prey by sympatric wolves and wolverines. Our findings reveal that wolves facilitate wolverines by providing scavenging opportunities, where biomass available from kills is influenced by wolves’ prey preference and group size. Wolverines, like wolves, utilized kills heavily during winter, when increased access to food is important to wolverine reproductive rates. Wolverines exhibited caching behavior, possibly reducing exposure to interspecific competition, while serving an important role in the depletion of carrion biomass.

Wet scavenging of multi-mode 137Cs aerosols following the Fukushima accident: Size-resolved microphysics modeling with observed diameters

Wet scavenging was critical in the atmospheric transport of 137Cs aerosols following the Fukushima accident. The aerosol size diversity and related microphysical processes produce complex behaviors during wet scavenging. Such behaviors are difficult to investigate using traditional simplified size distributions, resulting in inaccurate modeling. This study establishes an improved size-resolved wet scavenging model that considers the activation process. Using this model, five monodisperse simulations with five representative observed diameters with realistic solubility setting are performed to investigate the spatiotemporal wet scavenging behaviors of 137Cs aerosols. One polydisperse simulation with an empirical size distribution is also validated against the observation. The results reveal that 137Cs aerosols with diameters of 0.6 and 2.0 μm are mainly subject to below-cloud scavenging, which makes a significant contribution to low-deposition areas (<300 kBq/m2). For 137Cs aerosols with diameters of 6.4, 15, and 30 μm, in-cloud scavenging dominates, and the resulting depositions make significant contributions in high-deposition areas. The polydisperse results satisfy the criteria for good performance and better agree with the size, and deposition observations than the five monodisperse simulations, whereas for the concentration, the results show a similar RANK2 with the best mono1 and mono2 cases and reach the satisfactory criteria. These findings reveal the complex behavior and wet scavenging process of multi-mode 137Cs aerosols, improving our understanding and modeling.

Free radical scavenging behaviour of the plant-beneficial secondary metabolite 2,4-diacetylphloroglucinol derivatives under physiological conditions: A joint experimental and theoretical study

Undoubtedly, natural products (NPs) offer a crucial foundation for crafting novel biologically relevant scaffolds. Among these, 2,4-diacetylphloroglucinol (DAPG) stands out as a polyketide compound produced by Pseudomonads spp, showcasing substantial antimicrobial activity. This study focuses on synthesising derivatives of DAPG and delving into their structural characteristics, tautomerism, and antiradical properties. Through density functional theory (DFT) calculations at the B3LYP/def2-SVP level, we examined the thermodynamic parameters governing the double H+/e−radical trapping processes. These investigations encompassed both gas phase and physiological environments (lipid-like and aqueous solution media). Comparative analyses were conducted with its analogue (2,4-diisobutyrylphloroglucinol, DBPG), its parent compound (phloroglucinol, PG), and a commercial antioxidant standard (2-butylated hydroxyanisole, 2-BHA). This study unveils that DAPG exhibits a preference for double-sequential proton loss electron transfer (dSPLET) as the favoured mechanism within physiological environments. Additionally, we computed redox potentials and equilibrium constants to discuss the effectiveness of the overall scavenging process against diverse reactive oxygen, nitrogen, and sulphur species (ROS, RNS, and RSS). Further insights were gained through molecular docking studies, evaluating the potential inhibition against several ROS-generating enzymes such as xanthine oxidase (XO), lipoxygenase (LO), CYP2C9 (CP450), and NADPH-oxidase (NO). Comprehensive discussions regarding the effects of modifications on PG rings were also conducted. In addition, bioinformatic POM (Petra/Osiris/Molinspiration) analyses were reported to aid in clarifying the experimental data and DFT calculations. Ultimately, this study advocates for the development of potent acyl phloroglucinols (ACPLs)-based antiradical agents, shedding light on how structural characteristics influence their radical scavenging potential.

Enterococcus faecalis provides protection during scavenging in carrion crow ( Corvus corone).

The gut microbiota significantly influences host physiology and provides essential ecosystem services. While diet can affect the composition of the gut microbiota, the gut microbiota can also help the host adapt to specific dietary habits. The carrion crow ( Corvus corone), an urban facultative scavenger bird, hosts an abundance of pathogens due to its scavenging behavior. Despite this, carrion crows infrequently exhibit illness, a phenomenon related to their unique physiological adaptability. At present, however, the role of the gut microbiota remains incompletely understood. In this study, we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing, China. Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria (75.51%) and Firmicutes (22.37%). Significant differences were observed in the relative abundance of Enterococcus faecalis among groups, highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows. Subsequently, E. faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection. Results showed that E. faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin 6 (IL-6), prevented S. enterica colonization, and regulated the composition of gut microbiota in mice, thereby modulating the host's immune regulatory capacity. Therefore, E. faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior, offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

New Geographical Distribution of Dung Beetles (Coleoptera: Scarabaeidae: Scarabaeinae) from Indian States

Dung beetles, belonging to the subfamily Scarabaeinae, represent a globally distributed group of insects known for their scavenging behaviour, feeding primarily on animal excrement. Their ecological importance lies in their central role in recycling organic matter, with a particular focus on manure. A total of 6,886 species of this subfamily have been discovered, of which over 450 species are reported from India. In the present work, a total of 27 dung beetle species belonging to 8 genera from different Indian states are examined. These results are based on recent collections carried out as part of faunal surveys at various sites. The state distribution of the dung beetle is revised based on the material and literature records. This study documented the current status of some of the dung beetles in peninsular India and is intended to help properly discuss the scarab beetle diversity in the future. Through intensive investigations into unexplored areas, more Scarabaeinae species are expected in the future.

Polyphenol oxidase inactivation from apple juice by Al-based metal–organic frameworks: New anti-browning strategy in fruits and vegetables

Polyphenol oxidase (PPO) is critical due to enzymatic browning in fruits and vegetables, developing economic impact in fruits industry. Metal-Organic Frameworks (MOF) have shown interesting characteristics such as water stability, low toxicity, and good adsorption yield, making them good candidates for PPO inactivation. Al-based-MOFs, MIL-53(Al), DUT-5, and MIL-110 were tested as PPO inactivators in apple juice by enzyme-MOF interactions at r.t. through two possible mechanisms, i) substrate scavengers (substrates:catechol and 4-methylcatechol) or ii) enzyme activity modifiers. The scavenging behavior of Al-based-MOFs was moderate, in the same magnitude, being catechol adsorption better than 4-methylcatechol. PPO activity was reduced by at least 70% by MIL-53(Al)/DUT-5 in 10/30 min respectively, and MIL-110 inactivated PPO in 50 min with some structural modifications. Enzyme-MOF interactions are major responsible for PPO inactivation. This could be a new applicability of MOFs, as an alternate PPO inactivation process, easily included in juice processing, retaining sensorial/nutritional properties, developed at r.t thus energy-cost-effective.

Characterization and optimization of clove oil-loaded nanomicelles for the possible topical use of bacterial infection-led atopic dermatitis

BackgroundAtopic dermatitis is an abnormal skin condition that impacts a significant number of people in the US, with an estimated 9.6 million children and 16.5 million adults being affected by it. The study aimed to characterize and optimize clove oil-based nanomicelles for the possible topical use of bacterial infection-led atopic dermatitis. Clove oil-loaded nanomicelles were produced and carefully analyzed for vesicle diameter, polydispersity index (PDI), zeta potential, morphological attributes, entrapment efficiency, in vitro release, stability, dermatokinetic parameters, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging behavior and antibacterial activity. Different models, such as Korsmeyer, Higuchi, first order, and zero order were employed to evaluate the in vitro release from the formulations.ResultsThe average size of the clove oil nanomicelles was found to be 100.15 nm with a PDI of 0.2104; they were observed to be darker against a light background. The evaluated mean zeta size was 121.3 nm, the zeta potential was − 15.31 mV. The inhibitory concentration 50 (IC50) of the formulation was 61.32 ± 0.98 μg/mL; clove oil was 73.56 ± 1.63 μg/mL, against ascorbic acid was 54.51 ± 0.79 μg/mL. Among the four models tested for in vitro release kinetics, the Korsmeyer Peppas model was followed by the nanomicelles formulation. Clove oil nanomicelles generated a higher concentration of 148.68 w/v on the skin epidermis within 1.5 h, whereas the conventional formulation exhibited 55.287 w/v. Moreover, clove oil nanomicelles generated a higher concentration of 125.84 µg/mL on the skin's dermis within 2 h, whereas the conventional formulation produced 68.263 µg/mL. The nanomicelles also inhibited bacterial growth within a 24-h period.ConclusionsThe study presents initial evidence regarding the potency of clove oil-based nanomicelles and their enhanced efficiency on the skin. Thus, the prepared formulation can further be studied and incorporated for the possible use against bacterial infection-led atopic dermatitis.Graphical abstract

Ceria tubular nanoarchitecture antioxidants achieve sustainable fuel cell devices via tuning the oxophilicity of Pt catalytic surfaces and radical scavenging

The durability of polymer electrolyte membrane fuel cells (PEMFCs) crucially depends on the use of antioxidants to prevent electrocatalyst degradation. Here, we report for the first time, by in situ X-ray absorption and H2O2 electrochemistry, that ceria significantly weakens the Pt-surface oxophilicity, which determines oxygen reduction (ORR) activity and durability, within the PEMFC cathode. Ceria mitigates catalyst disintegration and improves ORR durability by Pt oxophilicity reduction and its inherent radical scavenging behavior. We also found that the antioxidation efficacy of ceria could be finely tuned through nanostructuring. Among various ceria nanostructures, tubular ceria nanoarchitectures (CeOx NT), designed to have the largest surface area and abundant oxygen vacancies, enable the most potent interaction between Pt and Ce without direct chemical contact with Pt. The nanotubular structure confers superior multifunctional antioxidant therapeutic efficacy to Pt/C catalyst in PEMFCs, resulting in outstanding durability that retains 94% of initial performance after 100-hour tests.

Monitoring the dynamics of consumption of ungulate game by-products in vulture feeding stations in Iberian Mediterranean ecosystems

Vulture feeding stations (VFS) are strategic sites for the management of ungulate game by-products, with major implications for the conservation of obligate avian scavengers. These feeding points are designed to prevent access by facultative mammalian scavengers and to reduce the risk of trophically transmitted pathogen infection through scavenging behaviour. The aim of this study, using camera trap video recordings, was to evaluate the feeding dynamics around 32 lots of ungulate game by-products deposited in VFS in southern Spain. During the study period (2017–2022), 11 different avian and mammal scavenger species was detected. Also, many feeding events involving all scavenger species (51.1%; 362/709) and mammal scavenger species (23.4%; 166/709) was recorded. A significantly earlier presence of major obligate scavengers (Gyps fulvus and Aegypius monachus) (P = 0.023) and a lower persistence of by-products deposited (P < 0.001) were detected during October–December compared to January–March. Our results confirm that VFS play an important role in vulture conservation in Iberian Mediterranean ecosystems. However, we also point out the potential risk of VFS as hotspots of foodborne pathogens for mammal scavengers, particularly when the hunting offal persists longer. Consequently, we urge the competent authorities to update the regulations affecting VFS management, and hunting estate managers to make every effort to correctly apply those preventing scavenging mammals from gaining access to VFS. Further studies tackling access of non-target species to VFS are also warranted to properly assess the sanitary implications and geographical extent of these problems for mammal species inhabiting areas where VFS are installed.

Risk from a top predator and forest structure influence scavenging by smaller carnivores

AbstractLarge carcasses often attract multiple carnivore species, so subordinate carnivores must weigh the reward of a profitable meal with the risk of being attacked by dominant carnivores. These risk–reward trade‐offs are likely influenced by a variety of factors, including scale‐dependent risk from dominant carnivores (e.g., short‐ vs. long‐term risk) and the amount of carcass remaining. In the southeastern United States, human hunters provision a large amount of white‐tailed deer carrion, which appears to be an important food source for coyotes (a novel top predator), but we know little about how coyotes influence the scavenging behavior of smaller carnivores. In this study, we evaluated the relative importance of risk from coyotes, vulture activity, forest structure, and remaining food on bobcat, gray fox, raccoon, and opossum scavenging by deploying 71 deer carcasses within a managed forest in South Carolina during January 2020 and 2021. We found that coyotes only had direct effects on bobcat behavior, suggesting that competition for carcasses was greatest between these two species. However, the relative importance of long‐ versus short‐term risk from coyotes was dependent on the stage in the scavenging process. Effects from forest structure were also stage‐dependent, where tree density and age were related to carcass discovery for bobcats and raccoons, while minimal understory cover facilitated bobcat, gray fox, and opossum scavenging, despite short‐term risk from coyotes. Vulture activity appeared to serve as a cue for gray foxes to discover carcasses. Ultimately, we found that risk from coyotes had species‐specific and context‐dependent effects on smaller carnivore scavenging. This represents some of the first direct evidence of how coyotes alter smaller carnivore behavior in a region where coyotes are a novel top predator. However, forest structure (particularly understory cover) seemed to mediate risk from coyotes, highlighting how habitat can influence predator–predator interactions. Future research should also investigate these interactions during other times of the year and try to quantify how human‐provisioned carcasses influence populations and communities.

Scavenging patterns of an inbred wolf population in a landscape with a pulse of human‐provided carrion

AbstractScavenging is an important part of food acquisition for many carnivore species that switch between scavenging and predation. In landscapes with anthropogenic impact, humans provide food that scavenging species can utilize. We quantified the magnitude of killing versus scavenging by gray wolves (Canis lupus) in Scandinavia where humans impact the ecosystem through hunter harvest, land use practices, and infrastructure. We investigated the cause of death of different animals utilized by wolves, and examined how the proportion of their consumption time spent scavenging was influenced by season, wolf social affiliation, level of inbreeding, density of moose (Alces alces) as their main prey, density of brown bear (Ursus arctos) as an intraguild competitor, and human density. We used data from 39 GPS‐collared wolves covering 3198 study days (2001–2019), including 14,205 feeding locations within space–time clusters, and 1362 carcasses utilized by wolves. Most carcasses were wolf‐killed (80.5%) while a small part had died from other natural causes (1.9%). The remaining had either anthropogenic mortality causes (4.7%), or the cause of death was unknown (12.9%). Time spent scavenging was higher during winter than during summer and autumn. Solitary wolves spent more time scavenging than pack‐living individuals, likely because individual hunting success is lower than pack success. Scavenging time increased with the mean inbreeding coefficient of the adult wolves, possibly indicating that more inbred individuals resort to scavenging, which requires less body strength. There was weak evidence for competition between wolves and brown bears as well as a positive relationship between human density and time spent scavenging. This study shows how both intrinsic and extrinsic factors drive wolf scavenging behavior, and that despite a high level of inbreeding and access to carrion of anthropogenic origin, wolves mainly utilized their own kills.

Atmospheric radioactive nuclide deposition on the coast of the Maowei Sea, northern Beibu Gulf, China

The natural radioisotopes 7Be, 210Pb, and 210Po, with different half-lives, are all particle-reactive and serve as natural tracers to study sources and transportation of sediments, sedimentation rates, and sediment chronology. Atmospheric deposition of these radioisotopes is the premise and foundation of their tracing application. The Maowei Sea is a semi-closed bay along the Beibu Gulf, which is an important gulf in the northwest of the South China Sea, but the atmospheric deposition of the abovementioned radioisotopes has not been systematically reported along the coast. In this research paper, the atmospheric depositional fluxes of 7Be, 210Pb, and 210Po were observed over a period from June 2018 to December 2021 on the coast of the Maowei Sea. The annual atmospheric depositional fluxes (Bq m-2 yr-1) of 7Be, 210Pb, and 210Po on the coast of the Maowei Sea were 496.80, 201.72, and 58.08, respectively. The distributions for 7Be and 210Pb depositional fluxes during a whole year (years 2019 and 2021) followed a bimodal pattern, with one peak from February to April and another peak from August to October, while the distribution for 210Po depositional flux showed only one peak during the year of 2019 and another during 2021. The deposition flux and activity of 7Be showed a strong positive correlation with the deposition flux and activity of 210Pb, respectively; the deposition flux and activity of 210Po also showed positive correlations with the deposition fluxes and activities of 210Pb and 7Be, respectively, indicating a similarly scavenging behavior from the atmosphere. A Pearson correlation matrix was used to illustrate the factors influencing the atmospheric depositions and found that precipitation, air quality index (AQI), and PM (both PM2.5 and PM10) were the major factors that influenced the deposition of these three radionuclides. Precipitation had significant positive correlations with the deposition fluxes of all three radionuclides, indicating that, for these radionuclides, rainfall was the main scavenging way from the atmosphere. The observations for specific single rainfall events and their air mass backward trajectory analyses showed that the air masses movement during the rainfall may be another important factor that impacted the depositional fluxes for 7Be, 210Pb, and 210Po.

Comparative Effect of Ascaridia Galli Infection on the Two Laying Hen Lines on the Liver Function and Immune Response.

Chicken production is quickly rising due to the low associated costs and the capability of poultry to convert nutrients into biological protein along with chicken meat accounting for 30% of all animal protein eaten by humans. Despite advances in poultry production, parasitic illnesses in laying hens remain a problem. Farm birds reared in semi-intensive and free-range systems are more prone to parasite infections due to the absorption of polluted water and food from scavenging behaviors and waste droppings. In this study, the effects of Ascaridia galli infectionon the immune response and liver function of two laying hen lines are compared, and their infection resistance is determined. In total, 50 laying hens at eight weeks of age were used (25 Lohmann brown-classic and 25 Lohmann lsl-lite), and each line was divided into two groups: an infected group (n=15), which was orally infected with a single dose of 500 A. galli embryonated eggs, and a control group (n=10), which was given normal saline. After four and eight weeks, blood was collected from the wing vein to assess the serum's AST, ALT, total protein, and IgY levels. The results demonstrated that the infected Lohmann brown-classic and Lohmann lsl-lite chickens presented significantly increased (P≤0.05) AST, ALT, and IgY, compared to the respective control group. Moreover, Lohmann brown-classic hens presented a significantly increased (P≤0.05) IgY concentration four weeks after infection, compared to Lohmann lsl-lite hens. From our results, it can be concluded that genetic variation plays a crucial role in the immune response against A. galli, where the Lohmann brown-classic line was found to be more resistant, compared to theLohmann lsl-lite line.

Ultrasound-Assisted Mineralization of 2,4-Dinitrotoluene in Industrial Wastewater Using Persulfate Coupled with Semiconductors.

Oxidative degradation of 2,4-dinitrotoluenes in aqueous solution was executed using persulfate combined with semiconductors motivated by ultrasound (probe type, 20 kHz). Batch-mode experiments were performed to elucidate the effects of diverse operation variables on the sono-catalytic performance, including the ultrasonic power intensity, dosage of persulfate anions, and semiconductors. Owing to pronounced scavenging behaviors caused by benzene, ethanol, and methanol, the chief oxidants were presumed to be sulfate radicals which originated from persulfate anions, motivated via either the ultrasound or sono-catalysis of semiconductors. With regard to semiconductors, the increment of 2,4-dinitrotoluene removal efficiency was inversely proportional to the band gap energy of semiconductors. Based on the outcomes indicated in a gas chromatograph-mass spectrometer, it was sensibly postulated that the preliminary step for 2,4-dinitrotoluene removal was denitrated into o-mononitrotoluene or p-mononitrotoluene, followed by decarboxylation to nitrobenzene. Subsequently, nitrobenzene was decomposed to hydroxycyclohexadienyl radicals and converted into 2-nitrophenol, 3-nitrophenol, and 4-nitrophenol individually. Nitrophenol compounds with the cleavage of nitro groups synthesized phenol, which was sequentially transformed into hydroquinone and p-benzoquinone.

Spatial modeling of road collisions of striped hyena (Hyaena hyaena) in Israel

AbstractThe striped hyena is an enigmatic species that is little studied. It is mainly found in semiarid and arid regions and is described as elusive, cryptic, nocturnal, and solitary. The global distribution is disjunct, and the species suffers from human persecution. However, specific communities consider them to be commensals. Owing to their scavenging behavior, striped hyenas are disproportionately involved in vehicular‐wildlife incidents, most of which are fatal. By combining data collected by the Scientific Data Department of the Israel Nature Parks Authority with information from remote sensing imaging, we illustrate the distribution of the striped hyena, identify critical habitats in which they occur, and illustrate the zones with the highest conflicts in the whole of Israel and the West Bank. The scale of striped hyena mortality (44.3/year) suggests that populations are much higher than previous estimates. We found more striped hyena carcasses on road/highway networks and urban areas than in natural surroundings. Our results should help focus the efforts to mitigate wildlife road kills by implementing conservation measures in urban areas and inter‐city highways, with a stress on striped hyena mortality.

El Cóndor Devorador Tiwanaku (590-1150 D.C.): Convención, divinidad, y alegoría de un carroñerismo ritual

The pre-Hispanic iconography of the Andes around violence, death, and fertility has been associated with sacred animals of various types and meanings whose rites persist to the present time. In Tiwanaku (590-1150 AD) the condor assumes these aspects within the theme that we call Tiwanaku Devouring Condor (CDT). The CDT`s images suggest rites associated with death, transformation, and propitiation through the sacralization of his scavenger behavior, and allow us to delve into the definition of a new category of iconographic themes defined as “Devourers”, in which the CDT positioned as the most continuous and ancient during the Middle Horizon. We propose that the CDT was a product of a ritual symbolism in which many cultures of the Andes converge.

The roles of ethanol and isopropanol as hole scavengers in the photoreduction reaction of graphene oxide by TiO2: A competition of oxygenated groups removal and carbon defects invasion

In this study, we performed the photoreduction of graphene oxide on TiO2′s surface with three solvents ethanol, isopropanol, and water under ultraviolet irradiation. The materials were assessed by different techniques such as X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectroscopy, and Field-emission Scanning electron microscope (FE-SEM) to elucidate the scavenging effects of the solvents on the grafting of reduced graphene oxide (rGO) to the surface of TiO2. The photoreduction process was established chemical bondings between rGO and TiO2. Using alcohols as solvents, the photoreduction efficiency was significantly improved compared with water solvent, signifying by the lower amount of C–O than C–C bonds determined by X-ray photoelectron spectroscopy (XPS). As a result, isopropanol showed better scavenging behaviors than that of ethanol. The photo-reduced graphene oxide products also possessed fewer carbon defects while using isopropanol than water or ethanol. The results confirmed the scavenging effects of common alcohols by integrating them with statistical analysis (ANOVA, etc.). Moreover, we also showed that the use of alcohols is highly effective in cutting carbon groups containing oxygen in the following order: isopropanol > ethanol > water. However, the appearance of carbon structural defects was observed by another rule: ethanol > water > isopropanol. This work aimed to indicate the pros and cons when dealing with different solvents and helped us to choose the optimal medium for the photoreduction of graphene oxide grafted on the surface of TiO2.

Eating smart: Free-ranging dogs follow an optimal foraging strategy while scavenging in groups

Foraging and acquiring of food is a delicate balance between managing the costs (both energy and social) and individual preferences. Previous research on solitarily foraging free-ranging dogs showed that they prioritise the nutritionally highest valued food, but do not ignore other less valuable food either, displaying typical scavenger behaviour. We conducted a similar experiment on 136 groups of dogs with the same set-up to see the change in foraging strategies, if any, under the influence of social cost like intra-group competition. We found multiple differences between the strategies of dogs foraging alone versus in groups with competition playing an implicit role in the dogs’ decision making when foraging in groups. Dogs continually assessed and evaluated the available resources in a “patch,” transitioning from random foraging to systematic foraging with time and more information. Dogs in groups used an, “eat first, sample afterwards” strategy whereas individual dogs sampled thoroughly before eating. Additionally, dogs in groups were quicker and more likely to respond to the experimental set-up and eat from it. The dogs adjusted their behaviour in terms of effort and time allocated according to the quality of the “patch.” Foraging in groups also provided benefits of reduced individual vigilance. The various decisions and choices made lend support to the optimal foraging theory wherein the dogs harvested the nutritionally richest patch possible with the least risk and cost involved but were willing to compromise if that was not possible. This underscores the cognitive, quick decision-making abilities and adaptable behaviour of these dogs, which is likely to have influenced the process of dog domestication.

Budaya Kesehatan Pemulung di TPA Regional SARBAGITA Kelurahan Pedungan Kecamatan Denpasar Selatan Kota Denpasar

Research on the Health Culture of Scavengers at the SARBAGITA Regional TPA, began with cases of skin diseases that mostly suffered by scavengers as a result of their work to find junk items in waste. This study tries to examine the health culture of scavengers in their daily lives. The main problem in this research is focused on the health behavior of scavengers at the SARBAGITA Regional TPA. This study uses the theory of health behavior popularized by Dunn. The method used is a qualitative research method using data collection techniques through observation, interviews, and literature study. The analysis used in this research is interpretive descriptive. Where this study shows that the health culture of the scavengers at the SARBAGITA Regional TPA is part of their health behavior, which results in preventive and promotive behavior of scavengers in maintaining and improving their health. There is also a caring and apathetic behavior of scavengers in responding to the health problems they suffer.