Wild chimpanzees modify modality of gestures according to the strength of social bonds and personal network size

Primates form strong and enduring social bonds with others and these bonds have important fitness consequences. However, how different types of communication are associated with different types of social bonds is poorly understood. Wild chimpanzees have a large repertoire of gestures, from visual gestures to tactile and auditory gestures. We used social network analysis to examine the association between proximity bonds (time spent in close proximity) and rates of gestural communication in pairs of chimpanzees when the intended recipient was within 10 m of the signaller. Pairs of chimpanzees with strong proximity bonds had higher rates of visual gestures, but lower rates of auditory long-range and tactile gestures. However, individual chimpanzees that had a larger number of proximity bonds had higher rates of auditory and tactile gestures and lower rates of visual gestures. These results suggest that visual gestures may be an efficient way to communicate with a small number of regular interaction partners, but that tactile and auditory gestures may be more effective at communicating with larger numbers of weaker bonds. Increasing flexibility of communication may have played an important role in managing differentiated social relationships in groups of increasing size and complexity in both primate and human evolution

Microbiological and Nutritional Characteristics of Locally Fermented Fufu Commonly Sold in Amai, Delta State, Nigeria

Cassava (Manihot esculenta) is the raw material for various local dishes around the world with popular ones such as garri, eba, fufu, tapioca abacha and starch in Nigeria, however, microbial and nutritional quality information are scanty on these dishes. Consequently, the objective of this paper was to evaluate the microbiological and nutritional characteristics of Locally Fermented Fufu commonly sold in Amai, Delta State, Nigeria using appropriate standard methods. Data obtained from the sample analysis revealed the presence of various species of microorganisms, including Staphylococcus spp., Lactobacillus spp., Pseudomonas spp., and Bacillus spp. Aspergillus spp and Rhizopus spp however, Aspergillus spp was the predominant fungi. The outcome of the nutritional analysis of the fufu product reveals some parameters such as moisture content, protein content, carbohydrate content. The result revealed high carbohydrate (87.26%) indicating fufu as an energy-giving food, other compositions such as fiber content (3.75%) and ash content (2.22%) suggest that fufu promotes gut health and digestibility. The results of this study shed light on the cultural, macroscopic, microscopic, and nutritional characteristics of the of fufu samples. The proximate analysis of the fufu provided valuable insight to its nutritional content which specifies that fufu is rich in energy giving nutrient (carbohydrate)

Tropical field stations yield high conservation return on investment

Conservation funding is currently limited; cost-effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations? conservation return on investment and explored the impact of COVID-19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These ?earth observatories? provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly

Brain structure and function: a multidisciplinary pipeline to study hominoid brain evolution

To decipher the evolution of the hominoid brain and its functions, it is essential to conduct comparative studies in primates, including our closest living relatives. However, strong ethical concerns preclude in vivo neuroimaging of great apes. We propose a responsible and multidisciplinary alternative approach that links behavior to brain anatomy in non-human primates from diverse ecological backgrounds. The brains of primates observed in the wild or in captivity are extracted and fixed shortly after natural death, and then studied using advanced MRI neuroimaging and histology to reveal macro- and microstructures. By linking detailed neuroanatomy with observed behavior within and across primate species, our approach provides new perspectives on brain evolution. Combined with endocranial brain imprints extracted from computed tomographic scans of the skulls these data provide a framework for decoding evolutionary changes in hominin fossils. This approach is poised to become a key resource for investigating the evolution and functional differentiation of hominoid brains.</jats:p

Tropical field stations yield high conservation return on investment

Conservation funding is currently limited; cost‐effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID‐19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km 2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly

Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology

1. The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviours such as language and sophisticated tool use. To understand this evolution, a diverse sample set of humans' closest relatives with varying socio-ecologies is needed. However, current brain banks predominantly curate brains from primates that died in zoological gardens. We try to address this gap by establishing a field pipeline mitigating the challenges associated with brain extractions of wild primates in their natural habitat.2. The success of our approach is demonstrated by our ability to acquire a novel brain sample of deceased primates with highly variable socio-ecological exposure and a particular focus on wild chimpanzees. Methods in acquiring brain tissue from wild settings are comprehensively explained, highlighting the feasibility of conducting brain extraction procedures under strict biosafety measures by trained veterinarians in field sites.3. Brains are assessed at a fine-structural level via high-resolution MRI and state-of-the-art histology. Analyses confirm that excellent tissue quality of primate brains sourced in the field can be achieved with a comparable tissue quality of brains acquired from zoo-living primates.4. Our field methods are noninvasive, here defined as not harming living animals, and may be applied to other mammal systems than primates. In sum, the field protocol and methodological pipeline validated here pose a major advance for assessing the influence of socio-ecology on medium to large mammal brains, at both macro- and microstructural levels as well as aiding with the functional annotation of brain regions and neuronal pathways via specific behaviour assessments

The Effect of Antigen Retrieval on Cells Fixed in 10% Neutral Buffered Formalin Followed by Transfer to 70% Ethanol

Fixation in 10% neutral buffered formalin prior to transfer to 70% ethanol for one week has been shown to adequately preserve immunorecognition of PCNA, cytokeratins AE1/AE3 and EGFr. This study investigated whether 12 hrs fixation in 10% NBF plus transfer to 70% ethanol for 4 weeks would similarly preserve immunorecognition to an extent where antigen retrieval (AR) used to reverse the masking effects of fixation on some antigens would not be necessary. Two cell lines, DU145 and SKOV3 were grown on coverslips and fixed either for 684 hrs in 10% NBF or for 12 hrs in 10% NBF which was then replaced with 70% ethanol for 672 hrs. The second experiment had the same design except an additional set of cells were subjected to heat-induced AR concomitantly. PCNA, cytokeratins AE1/AE3, and EGFr (membrane and cytoplasmic) were used to evaluate the effects of immunorecognition. Fixation in 10% NBF for 12 hrs plus transfer to 70% ethanol for 672 hrs did not preserve immunorecognition of PCNA adequately in either cell lines. Cytokeratins immunoreactivity was preserved by transfer to 70% ethanol. Cytoplasmic EGFr antigens were not adversely affected by 10% NBF fixation in either cell line and transfer to 70% ethanol had limited effects. With AR, there was little recovery of PCNA immunorecognition on cells fixed in only 10% NBF, but almost complete recovery for cells transferred to 70% ethanol. For cytokeratins there was complete recovery of immunorecognition either with only 10% NBF or 12 hrs plus transfer to 70% ethanol. For EGFr, AR resulted in complete loss of immunorecognition following either treatment. This study indicated that 12 hrs of fixation in 10% NBF plus transfer to 70% ethanol for 4 weeks with AR resulted in recovery of immunorecognition for PCNA and cytokeratins, but standard methods of AR caused loss of immunorecognition of EGFr

A standard tissue as a control for histochemical and immunohistochemical staining

The variable quality of histochemical and immunohistochemical staining of tissues may be attributed to pre-analytical and analytical variables. Both categories of variables frequently are undefined or inadequately controlled during specimen collection and preparation. Pre-analytical variables may alter the molecular composition of tissues, which results in variable staining; such variations may cause problems when different tissues are used as staining controls. We developed a standard tissue for use as a staining control. Our standard tissue contains five components: 1) nine combined human cell lines mixed with stroma from human spleen; 2) a squamous cancer cell line, A431; 3) fungus; 4) transverse sections of the mosquitofish and 5) normal human spleen. The first three components were embedded in HistoGel™ and all components were processed to paraffin and used to construct a single standard paraffin block. The muscles of mosquitofish and arteries of the spleen are positive controls for eosin staining, while other tissues are useful for assessing hematoxylin staining. The mosquitofish tissues also are excellent controls for the Masson trichrome stain and all mucin-related histochemical stains that we tested. The goblet cells of the intestine and skin stained strongly with Alcian blue, pH 2.5 (AB-2.5), mucicarmine, colloidal iron, periodic acid Schiff (PAS) or PAS-hematoxylin (PASH) and combination stains such as colloidal iron-PASH. Cell lines were not useful for evaluating histochemical stains except for PASH. The splenic stroma was a useful control for AB-2.5; however, eosin and mucin stains stained cell lines poorly, probably due to their rapid growth and associated loss of some differentiated characteristics such as production of mucins. Nevertheless, the cell lines were a critical control for immunohistochemical stains. Immunostaining of specific cell lines was consistent with the presence of markers, e.g., EGFr in DU145 cells. The cell lines expressed a wide range of markers, so they were useful controls for immunohistochemcial staining including EGFr, HER2, E-cadherin, cytokeratins, Ki67, PCNA, estrogen receptor, progesterone receptor, CD3, CD20 and CD45, activated (cleaved) caspase 3 and Bcl-2. The cell lines also were a control for the TUNEL stain

Combined effects of formalin fixation and tissue processing on immunorecognition

It is accepted that the aldehyde-based fixation of cells can affect the immunodetection of antigens; however, the effects of tissue processing on immunodetection have not been analyzed systematically. We therefore investigated the effects of aldehyde-based fixation and the individual steps of tissue processing on immunohistochemical detection of specific antigens. DU145 (prostate) and SKOV3 (ovarian) cancer cell lines were cultured as monolayers on microscope slides. The immunohistochemical detection of Ki67/MIB-1 and PCNA was evaluated after various times of fixation in 10% neutral-buffered formalin (NBF) plus after each of the individual cumulative steps of tissue processing. The effect of antigen retrieval (AR) was evaluated concomitantly as an additional variable. Our results indicate that, in addition to fixation, each of the different steps in tissue processing has effects on immunorecognition of the epitopes recognized by these antibodies. The extensive dehydration through ethanols to absolute ethanol had only modest effects except for the detection of Ki67/MIB-1 in SKOV-3 cells where the effect was stronger. In general, however, the establishment of a hydrophobic environment by xylene resulted in the greatest decrease in immunorecognition. Antigen retrieval was able to compensate for most, but not all of the losses in staining following fixation and exposure to xylene; however, AR gave very consistent results for most steps of tissue processing, suggesting that AR should also be used in staining for PCNA. The cellular variations that were noted indicate that the effects of fixation and other steps of tissue processing may depend upon how antigens are packaged by specific cells