136 research outputs found

    Recently identified features that help to distinguish ceremonial tsantsa from commercial shrunken heads

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    This is an anthropological investigation into a collection of 65 shrunken human heads, to determine if new characteristics can be identified to facilitate the differentiation between ceremonial tsantsa and commercial shrunken heads. Ceremonial tsantsa refers to shrunken heads mummified as war trophies within the ancient traditions and rituals of the Amazonian Shuar, Achuar, Awajún/Aguaruna, Wampís/Huambisa and Candoshi-Shapra (SAAWC). Commercial shrunken heads are comparatively modern objects constructed specifically for the collector market of the past. Low earning individuals in South and Middle America, outwith the SAAWC culture, who had access to corpses and appropriate medical or taxidermy provisions, produced these for trade purposes. These heads were made in abundance and do not present the same historical value or heritage as ceremonial tsantsa. The relevance of an accurate provenance for heads may directly impact museums, with regard to identifying the authenticity of a specimen and how they should handle any potential requests to return such artefacts to their cultural homes. Complying with current anthropological standards, a total of 6 ceremonial tsantsa and 36 commercial heads were identified. Greater confidence is prescribed to the assignment of commercial heads as their morphological appearance is at odds with the highly standardised presentation of ceremonial tsantsa. Many indicated that the processor had access to modern resources such as gloves and fine suturing equipment, which were not typically available to the SAAWC. Since traders sometimes closely replicating ceremonial tsantsa when shrinking and decorating heads for trade, limited certainty can be prescribed to this category. Minor deviations in ceremonial design resulted in 23 heads being defined as ambiguous in origin. Each head was examined by manual inspection, infrared reflectography (IRR), CT and microscopic hair analysis, with ten new differentiating characteristics identified. © 2016

    Shining a Light on Dense Granules – A Biochemical, Genetic and Cell Biological Investigation of an Essential but Understudied Compartment of the Malaria Parasite

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    Malaria is a significant infectious disease of tropical and sub-tropical regions that is caused by six species of Apicomplexan parasites of the genus Plasmodium. With 228 million cases and an estimated 619,000 mortalities worldwide in 2021 (1), this disease is endemic in developing countries in which the transmission vector, species of the Anopheles mosquito, most commonly A. gambiae, is found. Further, malaria is a major cause of mortality in children, with 65% of cases occurring in those under the age of 5 (2). Between 2000 and 2019 rates of malaria fatality decreased steadily, with a 10% increase in mortality in 2020 followed by a slight decline in 2021 (1). However, the disease remains a major global health burden and new insights into the pathogenesis of the disease are needed if new interventions are to be developed. The clinical symptoms of malaria are caused by invasion, replication within, and destruction of host red blood cells by the Plasmodium parasite. Invasion of the host cell by the parasite requires the highly regulated secretion of proteins from three specialised secretory organelles: micronemes, rhoptries, and dense granules (DGs). Microneme and rhoptry proteins function in host cell recognition attachment and invasion and establishment of the parasitophorous vacuole (PV), respectively, in Plasmodium spp. (3,4). DGs are speculated to be required for the erythrocyte remodelling that enables parasite survival and replication within the host cell post invasion, with known proteins functioning in transport of parasite effector proteins into the erythrocyte (5) and alteration of host cell mechanical properties (6). Host erythrocyte remodelling by the parasite is a process that may be exploited for development of drugs capable of inhibiting parasite growth and replication, blocking further cycles of infection. Very little is known about Plasmodium DGs, therefore shedding light on the biogenesis, protein composition and function of DGs in Plasmodium may aid drug development efforts. This project aims to address these questions in Plasmodium falciparum using molecular biological and bioinformatics techniques

    Ammonia emissions in tunnel-ventilated broiler houses

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    Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems.26527

    Facial preservation following extreme mummification: Shrunken heads

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    Shrunken heads are a mummification phenomenon unique to South America. Ceremonial tsantsa are ritually reduced heads from enemy victims of the Shuar, Achuar, Awajún (Aguaruna), Wampís (Huambisa), and Candoshi-Shapra cultures. Commercial shrunken heads are comparatively modern and fraudulently produced for the curio-market, often using stolen bodies from hospital mortuaries and graves. To achieve shrinkage and desiccation, heads undergo skinning, simmering (in water) and drying. Considering the intensive treatments applied, this research aims to identify how the facial structure can alter and impact identification using post-mortem depiction. Sixty-five human shrunken heads were assessed: 6 ceremonial, 36 commercial, and 23 ambiguous. Investigations included manual inspection, multi-detector computerised tomography, infrared reflectography, ultraviolet fluorescence and microscopic hair analysis. The mummification process disfigures the outer face, cheeks, nasal root and bridge form, including brow ridge, eyes, ears, mouth, and nose projection. Melanin depletion, epidermal degeneration, and any applied staining changes the natural skin complexion. Papillary and reticular dermis separation is possible. Normal hair structure (cuticle, cortex, medulla) is retained. Hair appears longer (unless cut) and more profuse following shrinkage. Significant features retained include skin defects, facial creases, hairlines and earlobe form. Hair conditions that only affect living scalps are preserved (e.g. nits, hair casts). Ear and nose cartilage helps to retain some morphological information. Commercial heads appear less distorted than ceremonial tsantsa, often presenting a definable eyebrow shape, vermillion lip shape, lip thickness (if mouth is open), philtrum form, and palpebral slit angle. Facial identification capabilities are considered limited, and only perceived possible for commercial heads

    Witness artistic rendition and its impacts on visual memory for forensic facial composite creation

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    In the absence of photographic or other identifying evidence, composites provide crucial intelligence in police investigations, though their accuracy depends on a witness’s facial memory and recall. The purpose of this study is to investigate a novel technique aimed at increasing face recall and composite effectiveness. In this study, participants viewed a facial photograph, recalled the face using a cognitive interview and created a composite with a forensic artist. One group of participants (control) who worked with an artist, the usual procedure, were compared with another group (experimental) who sketched the face themselves prior to the cognitive interview. Witness memory was then measured by assessing the number of “units of information” produced during free recall of the face, as well as the identifiability of the composites, evaluated by an additional group of participants who attempted to name the sketched composites. Results showed, relative to the control group, that the experimental witness group provided more detailed descriptions of the face and that this improvement to memory led to the creation of more identifiable composites. Therefore, the findings suggest that this artistic rendition technique enhances both the cognitive interview and the accuracy of forensic facial composites. It was also found that participants’ self-rated measures of drawing and observant behaviour were positively related to the accuracy of the participants’ composites. This simple technique could be implemented by police forces with minimal effort and impact on budget. It presents a straightforward and cost-efficient way to increase the identifiability of composite images without the need for additional lengthy training for forensic practitioners. Results suggest that the witness artistic rendition technique represents a novel, low-cost and simple method that could be used to increase composite accuracy

    Trends in micronutrient research since the SDGs: a global perspective

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    Sustainable food systems have become a central focus in efforts to combat micronutrient malnutrition, with increasing recognition of their role in achieving the Sustainable Development Goals (SDGs). This article presents a bibliometric analysis of micronutrient research from 2015 to 2023, examining trends and thematic clusters within the SDGs framework. Using data from the Web of Science and science mapping techniques, the study identifies key trends and thematic clusters that highlight evolving research priorities. Four major trends emerge: the application of machine learning, the exploration of macroalgae for their micronutrient potential, the use of CRISPR/Cas9 technology in biofortification, and concerns about heavy metal contamination in food. Research clusters show a strong focus on bone health, particularly osteoporosis and vitamin D, which align with SDG 3 (Good Health and Well-being). Yet research on micronutrient deficiencies, such as those in iron, zinc, and vitamin A, remains underrepresented despite their high global impact on malnutrition, especially in low- and middle-income countries, raising concerns about whether research priorities sufficiently address the SDGs. This study highlights the need for more targeted research to align with SDG 2 (Zero Hunger) and SDG 12 (Responsible Consumption and Production). The article concludes by stressing the importance to balance cutting-edge technological advances with a renewed emphasis to address critical micronutrient gaps to improve global nutrition and align with sustainable food system goals.fals

    Computational fluid dynamic simulation of earth air heat exchanger: A thermal performance comparison between series and parallel arrangements

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    This study uses Ansys Fluent to compare the thermal performance of series and parallel earth air heat exchanger (EAHE) systems for cooling. The model was validated using experimental data from published literature and matched simulation results. The sensitivity study examined how length, diameter, and ground surface coverings affected EAHE performance. The relationship between effectiveness and the Number Transfer Unit (NTU) of EAHE was explored along with the soil thermal regime. The simulation results show that the series EAHE can achieve a lower temperature drop than parallel. With an input air temperature of 32 C and EAHE lengths varying from 10 m to 50 m (in 10 m increments), the 50 m EAHE produced the lowest outlet air temperatures 27.2 C for the series configuration and 28.8 C for the parallel arrangement. Changing the EAHE diameter (4 6 in) results in a 0.2 C outlet air temperature drop for both setups. EAHE performed best under short grass soil cover, yielding 1.4 C and 0.5 C lower outlet air temperatures, for series and parallel arrangements than the asphalt cover. The pressure drop increased proportionally with EAHE s length. Simulation results indicate a 6 times larger pressure loss in the series design compared to the parallel setup. The effectiveness-NTU relationship shows that parallel EAHEs are 15 more effective than series ones

    On the scaling of activity in tropical forest mammals

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    Activity range – the amount of time spent active per day – is a fundamental aspect contributing to the optimization process by which animals achieve energetic balance. Based on their size and the nature of their diet, theoretical expectations are that larger carnivores need more time active to fulfil their energetic needs than do smaller ones and also more time active than similar‐sized non‐carnivores. Despite the relationship between daily activity, individual range and energy acquisition, large‐scale relationships between activity range and body mass among wild mammals have never been properly addressed. This study aimed to understand the scaling of activity range with body mass, while controlling for phylogeny and diet. We built simple empirical predictions for the scaling of activity range with body mass for mammals of different trophic guilds and used a phylogenetically controlled mixed model to test these predictions using activity records of 249 mammal populations (128 species) in 19 tropical forests (in 15 countries) obtained using camera traps. Our scaling model predicted a steeper scaling of activity range in carnivores (0.21) with higher levels of activity (higher intercept), and near‐zero scaling in herbivores (0.04). Empirical data showed that activity ranges scaled positively with body mass for carnivores (0.061), which also had higher intercept value, but not for herbivores, omnivores and insectivores, in general, corresponding with the predictions. Despite the many factors that shape animal activity at local scales, we found a general pattern showing that large carnivores need more time active in a day to meet their energetic demands. Introduction Activity range – the amount of time, in hours, spent active per day – is a fundamental outcome of the complex physiological and behavioral optimization process by which animals ensure that energy input keeps pace with energy output. In addition to basal metabolism, animals face costs of foraging, acquiring mates and shelter, building reserves for lean times and escaping predators (Carbone et al. 2007, Halle and Stenseth 2012). Environmental and ecological factors that vary through the day (e.g. luminosity, temperature, predation risk and competition avoidance) constrain activity to certain times, depending on morpho‐physiological limitations (Castillo‐Ruiz et al. 2012, Hut et al. 2012). In addition, animals need time to rest in order to recover their cognitive or physical condition (Siegel 2005). Thus, they must optimize their activity range to meet their resource requirements, while dealing with natural daily cycles and saving time for sleep/rest (Downes 2001, Siegel 2005, Cozzi et al. 2012). The resource requirements of mammals are related to basal metabolic rate, which scales positively with body mass (Kleiber 1932, Isaac and Carbone 2010), while predation risk decreases with body mass (Sinclair et al. 2003, Hopcraft et al. 2009). Because high predation risk constrains activity while high resource needs increases activity range (Cozzi et al. 2012, Suselbeek et al. 2014), the question arises whether and how activity range also scales with body mass. Day range (total distance travelled in a day) and home range (area in which animals perform their daily activities) scales positively with body mass and are key metrics to understand the resource requirements of an animal (McNab 1963, Kelt and Van Vuren 2001, Carbone et al. 2005, Tamburello et al. 2015). As activity range is related to space‐use metrics (i.e. home range and day range), it is hence, also related to the acquisition of energy. Given that, one might expect activity range to increase with body mass. However, we have a poor understanding of how this relationship actually looks. Previous work developed predictions of body mass scaling with day range (Garland 1983, Carbone et al. 2005) and travel speed (Carbone et al. 2007, Rowcliffe et al. 2016). From a simple physical viewpoint, activity range should equal the day range divided by average travel speed. It should thus be possible to infer the scaling of activity range with body mass from these relationships. Some of the variation in space use across species that is not explained by body mass is associated with different evolutionary histories and ecological traits (McNab 1963, Kelt and Van Vuren 2001, Price and Hopkins 2015, Tamburello et al. 2015). Diet is the most conspicuous of these, because primary and secondary productivity present different overall yields and accessibility for consumers (Jetz et al. 2004), which in turn influence individual movements (Carbone et al. 2005) and potentially activity range, when exploiting resources at different trophic levels. The nature of the diet aggravates the higher energetic demands of larger carnivores. Predators have considerable energetic constraints related to hunting and handling their prey (Gorman et al. 1998, Carbone et al. 1999) as animal prey can be rare, widely dispersed, unpredictable in time and space and not storable (Jetz et al. 2004, Carbone et al. 2007). Therefore, carnivores have the lowest energy supply rates (supply rate of usable resources available inside the home range), independent of body mass, when compared to other diet categories (Jetz et al. 2004) besides exploring larger areas and traveling greater daily distances (McNab 1963, Kelt and Van Vuren 2001, Carbone et al. 2005, Tamburello et al. 2015). Therefore, larger animals occupy larger areas than small ones, and carnivores occupy larger areas than do similar‐sized non‐carnivores (Jetz et al. 2004, Tamburello et al. 2015). To date, few studies have considered interspecific variation in activity range with body mass and other species traits. For example, van Schaik and Griffiths (1996) and Gómez et al. (2005) anecdotally suggested that larger mammal species are cathemeral (i.e. active day and night), which implies that they can be active during a larger proportion of the 24‐h cycle. Rowcliffe et al. (2014) found that activity range is positively correlated with body mass in tropical forest mammals in Panama. Ramesh et al. (2015) found a negative relationship between body mass and activity concentration (i.e. how concentrated in few hours is the activity of an animal during the day) in Indian mammals, also equating to a positive association between activity range and body mass. However, no study has explored variation in activity range across a diverse range of species, while controlling for phylogeny and diet. This has been, at least in part, due to a lack of consistent data available on a wide range of species. Recent work using camera traps (Oliveira‐Santos et al. 2013, Rowcliffe et al. 2014), however, has demonstrated that accurate estimates of activity range can be obtained from photographic records from camera traps. Given the large and rapidly increasing volume of camera‐trapping data available globally (Burton et al. 2015), these approaches, consistently applied across a wide range of studies, can provide an important basis for the large‐scale study of activity. Here, we provided simple empirical predictions for the scaling of activity range with body mass for mammals of different trophic guilds. To test these predictions, we estimated the activity range for 249 populations of 128 terrestrial mammal species across 19 tropical forests, and used a phylogenetically controlled mixed model to determine how activity range scales with body mass by diet. As larger animals occupy larger areas than small ones, and carnivores occupy larger areas than do similar‐sized non‐carnivores (Jetz et al. 2004), we hypothesize that carnivores will present a higher scaling of activity range with body mass and also higher activity ranges for a given mass (higher intercept) when compared to herbivores, omnivores and insectivores

    Fabrication and Properties of Porphyrin Nano- and Micro-particles with Novel Morphology

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    New types of porphyrin nano- and micro-particles composed of J- and H-heteroaggregates were prepared by electrostatic self-assembly of two oppositely charged porphyrins, tetrakis(4-trimethylammoniophenyl)porphyrin (H2TAPP4+) and tetrakis(4-sulfonatophenyl)porphyrin cobalt(II) (CoTPPS4−), in aqueous solutions. Transmission electron microscopy (TEM) images showed novel morphology and size distribution of porphyrin particles fabricated under different experimental conditions. The assembly process of the nano- and micro-particles was monitored by UV–Vis spectra. Fluorescence spectra and UV–Vis spectra provided optical information on the formation of the nano- and micro-particles. Cyclic voltammograms of the porphyrin particles indicated that the electron gain and loss of the H2TAPP4+ion were restrained, and the electron transfer of the CoTPPS4−ion was promoted in the J- and H-type porphyrin heteroaggregates within the particles. The stability and constitution of the nano- and micro-particles were confirmed by UV-light irradiation, heat-treatment, and pH and ionic strength changes. Photoelectrochemical measurements showed that the photoelectron transfer of TiO2modified with the particles was more efficient than that of TiO2sensitized by either monomers. The photoelectronic and photocatalytic properties of the products indicated that the pyramidal or spherical configuration of the nano- and micro-particles was favorable for the absorption and transfer of the energy. It can be found that TiO2sensitized by the porphyrin nano- and micro-particles exhibits significant improvement in energy conversion and photocatalytic activity with reference to pure TiO2
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