Now showing items 21-40 of 918

    • Evaluating critical success factors for implementing smart devices in the construction industry: An empirical study in the Dominican Republic

      Silverio-Fernández, Manuel; Renukappa, Suresh; Suresh, Subashini (Emerald, 2019)
      Purpose: The decentralisation of information and high rate of mobile content access in the construction industry provides an ideal scenario for improvement of processes via the implementation of the paradigm of the Internet of Things (IoT). Smart devices are considered as the objects interconnected in the IoT; therefore they play a fundamental role in the implementation of digital solutions during the execution of construction projects. This paper is aimed at assessing the critical factors for a successful implementation of smart devices in the construction industry. Design/methodology/approach: An empirical study was performed in the Dominican Republic. This country, located at the heart of the Caribbean presents an economy that strongly relies on the construction industry. Following a systematic approach, a qualitative data collection and analysis was performed based on semistructured interviews and content analysis to professionals of construction companies in the Dominican Republic, enquiring the concept of smart devices and critical success factors (CSFs) for implementing the devices in the industry. Findings: The key success factors obtained from the contestants were Leadership, technology awareness, company size, usability of proposed solution, cost of implementation and interoperability. Originality/value: This paper provides information to clients of the construction sector regarding the benefits of embedding smart devices into their business activities. Furthermore, this study provides a better understanding of the key factors to be considered by construction organisations when embedding smart devices into their projects. This study also provides recommendations for distinct stakeholders of the construction sector, such as policymakers, clients and technology consultants. Policymakers should especially consider factors such as technology awareness and leadership to develop the right policies for the integration of the IoT in construction projects. Technology consultants should be aware of the latest case studies of successful implementation of smart devices and IoT systems in the world in order to adapt and implement smart devices and IoT in their projects.
    • Knowledge management related training strategies in Kingdom of Saudi Arabia construction industry: An empirical study

      Renukappa, Suresh; Suresh, Subashini; Alosaimi, Hanouf (Taylor & Francis, 2019-03-04)
      The growing popularity of knowledge management (KM) in the construction industry has, unfortunately, not been matched by parallel empirical research in training and benefits of KM for construction industry in the Kingdom of Saudi Arabia (KSA). This paper discusses the KM related training strategies implemented in the Kingdom of Saudi Arabia construction industry. Given the relatively new and unexplored nature of the research problem, qualitative research method was adopted to collect and analyse data. Results are based on the analysis of data from 46 professionals from KSA construction organisations. This paper concludes that training interventions are a complex and context-embedded activity. The current study results suggests that for effective implementation of KM strategies, there is an urgent need for KSA construction industry to develop and deploy appropriate KM related management training programmes. Leadership plays an important role in breaking down barriers in achieving KM strategies. The practical implication of this research is that the KM should not only focus on the specific knowledge to be captured, shared, mapped and transferred between individuals but should also address strategic concerns at group and organisational levels.
    • Elo-rating for Tracking Rank Fluctuations after Demographic Changes Involving Semi-free-ranging Rhesus Macaques ().

      Wooddell, Lauren J; Kaburu, Stefano Sk; Suomi, Stephen J; Dettmer, Amanda M (American Association for Laboratory Animal Science, 2017-05-01)
      Rhesus macaques (Macaca mulatta) are gregarious primates that form despotic societies characterized by frequent and intense aggression. Within long-term social groups, demographic changes may influence hierarchical stability, potentially resulting in conflict and violently abrupt hierarchical changes. This conflict can result in serious implications for animal welfare, and thus, predictive tools would be invaluable to captive managers in determining social instabilities. Using the method Elo-rating to track rank changes and dominance stability, we predicted that demographic changes to a population of semi-free ranging rhesus macaques would result in changes in hierarchical stability. Over a 3 y period, dominance data were recorded on all troop members to track the hierarchy. Throughout the 3 y, significant changes occurred to the population (mainly due to health and colony management reasons; no changes specifically occurred for this study) including permanent removal of a large group of natal males, temporary and permanent removal of top-ranking females, and depositions of top-ranking families. Our retrospective study suggests that removing natal males was beneficial in promoting overall troop stability (that is, stability of dominance relationships), although remaining males opportunistically attempted to increase in rank, perhaps due to limited competition. Our results also suggest that removing top-ranking females, even temporarily, destabilized dominance relationships; consequently adjacently ranked females opportunistically increased in Elo-rating, both before and after the depositions of the α families. Thus, these challenges to the established hierarchy can be predicted by increases in Elo-rating within the β families after demographic changes to the α families. Our results suggest that the presence of natal males and the removal of top-ranking females should be minimized to maintain stable dominance relationships. In addition, longitudinal data reflecting dominance ranks, collected by using Elo-rating, may help managers of captive colonies in predicting dominance instabilities before they occur.
    • A portable, low-cost approach for photographing fluid preserved snake specimens- Recommendations with comments on optimizing specimen photography in Natural History collections

      Kaiser, Christine; Kaiser, Hinrich; Rickerl, Kaitlin J.; O'Shea, Mark (Society for the Study of Amphibians and Reptiles, 2018-12-12)
      Access to preserved specimens in museum collections is one of the key needs of those engaged in systematics research (e.g., Bi et al. 2013; Rocha et al. 2014; McLean et al. 2016). Yet, sometimes the constraints of research budgets and time prevent the optimal use of this critical resource, resulting in project delays, incomplete information, or flawed scientific conclusions. With many natural history museums now digitizing information related to specimens in their collections, imaging of specimens is a logical next step, and one of critical importance to make holdings available electronically to a broader audience (Baird 2010; Lister et al. 2011; Knight-Davis et al. 2015; Page et al. 2015). A complete 2D image library of all specimens in a collection may appear utopian at the moment, given the millions of specimens and lack of financial support for collections (e.g., Paknia et al. 2015). However, outside of visiting each collection to study individual specimens, or requesting loans of unique and valuable specimens, the lack of suitable specimen images means that some data may simply remain unavailable to researchers who cannot afford to obtain them. We wish to emphasize that the approach we advocate herein in no way negates the need to maintain and make accessible physical specimens in a collection. Although in rare cases where the lack of specimens is unavoidable (e.g., Marshall and Evenhuis 2015; Pape et al. 2016), there is no replacement for examining a well-preserved specimen. Our method should be regarded as an ancillary technique, useful when it is necessary to obtain preliminary data or when it is not possible to examine the specimen in person, and for archival purposes.
    • Intratympanic methylprednisolone versus gentamicin in patients with unilateral Ménière's disease: a randomised, double-blind, comparative effectiveness trial

      Patel, Mitesh; Agarwal, Kiran; Arshad, Qadeer; Hariri, Mohamed; Rea, Peter; Seemungal, Barry M; Golding, John F; Harcourt, Jonny P; Bronstein, Adolfo M. (Elsevier, 2016-11-16)
      Background Ménière’s disease is characterised by severe vertigo attacks and hearing loss. Intratympanic gentamicin,the standard treatment for refractory Ménière’s disease, reduces vertigo, but damages vestibular function and can worsen hearing. We aimed to assess whether intratympanic administration of the corticosteroid methylprednisolone reduces vertigo compared with gentamicin. Methods In this double-blind comparative effectiveness trial, patients aged 18–70 years with refractory unilateral Ménière’s disease were enrolled at Charing Cross Hospital (London, UK) and Leicester Royal Infirmary (Leicester, UK). Patients were randomly assigned (1:1) by a block design to two intratympanic methylprednisolone(62·5 mg/mL) or gentamicin (40 mg/mL) injections given 2 weeks apart, and were followed up for 2 years. All investigators and patients were masked to treatment allocation. The primary outcome was vertigo frequency over the final 6 months (18–24 months after injection) compared with the 6 months before the first injection. Analyses were done in the intention-to-treat population, and then per protocol. This trial is registered with ClinicalTrials.gov, number NCT00802529. Findings Between June 19, 2009, and April 15, 2013, 256 patients with Ménière’s disease were screened, 60 of whom were enrolled and randomly assigned: 30 to gentamicin and 30 to methylprednisolone. In the intention-to-treat analysis (ie, all 60 patients), the mean number of vertigo attacks in the final 6 months compared with the 6 months before the first injection (primary outcome) decreased from 19·9 (SD 16·7) to 2·5 (5·8) in the gentamicin group (87% reduction) and from 16·4 (12·5) to 1·6 (3·4) in the methylprednisolone group (90% reduction; mean difference –0·9,95% CI –3·4 to 1·6). Patients whose vertigo did not improve after injection (ie, non-responders) after being assessed by an unmasked clinician were eligible for additional injections given by a masked clinician (eight patients in the gentamicin group vs 15 in the methylprednisolone group). Two non-responders switched from methylprednisolone to gentamicin. Both drugs were well tolerated with no safety concerns. Six patients reported one adverse event each: three in the gentamicin group and three in the methylprednisolone group. The most common adverse event was minor ear infections, which was experienced by one patient in the gentamicin group and two in the methylprednisolone group. Interpretation Methylprednisolone injections are a non-ablative, effective treatment for refractory Ménière’s disease. The choice between methylprednisolone and gentamicin should be made based on clinical knowledge and patient circumstances.
    • Histology of the suprapubic and anogenital cutaneous glands in male cotton-top tamarins (Saguinus oedipus)

      Fontani, Sara; Tanteri, Gianfranco; Vaglio, Stefano; Delfino, Giovanni; Moggi-Cecchi, Jacopo (Karger, 2014-03-16)
      In cotton top tamarins (Saguinus oedipus), scent glands have been mostly studied in females from museum collections. This work aims to extend the investigation to male specimens, introducing a novel source of skin samples. Two adult males from zoo populations, one intact and one castrated, were immediately frozen after natural death. Skin samples were later collected at the thawing onset, soaked with cold fixative and processed for light microscopy. Sebaceous units of scent glands showed phasic secretory activity in the intact male and marked fibrosis in the castrated male. It appears, therefore, that light microscopy samples from frozen tissues provide detailed features that can disclose distinctive traits in specimens characterized by different hormonal balances.
    • Egalitarian despots: hierarchy steepness, reciprocity and the grooming-trade model in wild chimpanzees, Pan troglodytes.

      Kaburu, Stefano S. K.; Newton-Fisher, Nicholas E. (Elsevier, 2014-11-25)
      Biological market theory models the action of natural selection as a marketplace in which animals are viewed as traders with commodities to offer and exchange. Studies of female Old World monkeys have suggested that grooming might be employed as a commodity to be reciprocated or traded for alternative services, yet previous tests of this grooming-trade model in wild adult male chimpanzees have yielded mixed results. Here we provide the strongest test of the model to date for male chimpanzees: we use data drawn from two social groups (communities) of chimpanzees from different populations and give explicit consideration to variation in dominance hierarchy steepness, as such variation results in differing conditions for biological markets. First, analysis of data from published accounts of other chimpanzee communities, together with our own data, showed that hierarchy steepness varied considerably within and across communities and that the number of adult males in a community aged 20–30 years predicted hierarchy steepness. The two communities in which we tested predictions of the grooming-trade model lay at opposite extremes of this distribution. Second, in accord with the grooming-trade model, we found evidence that male chimpanzees trade grooming for agonistic support where hierarchies are steep (despotic) and consequent effective support is a rank-related commodity, but not where hierarchies are shallow (egalitarian). However, we also found that grooming was reciprocated regardless of hierarchy steepness. Our findings also hint at the possibility of agonistic competition, or at least exclusion, in relation to grooming opportunities compromising the free market envisioned by biological market theory. Our results build on previous findings across chimpanzee communities to emphasize the importance of reciprocal grooming exchanges among adult male chimpanzees, which can be understood in a biological markets framework if grooming by or with particular individuals is a valuable commodity.
    • Death of the alpha: within-community lethal violence among chimpanzees of the Mahale Mountains National Park

      Kaburu, Stefano S. K.; Sana, Inoue; Newton-Fisher, Nicholas E. (Wiley, 2013-06-25)
      Chimpanzees (Pan troglodytes) are capable of extreme violence. They engage in inter‐group, sometimes lethal, aggression that provides the winners with an opportunity to enlarge their territory, increase their food supply and, potentially, attract more mates. Lethal violence between adult males also occurs within groups but this is rare; to date, only four cases (three observed and one inferred) have been recorded despite decades of observation. In consequence, the reasons for within‐group lethal violence in chimpanzees remain unclear. Such aggression may be rare due to the importance of coalitions between males during inter‐group encounters; cooperation between males is also thought to be key in the defense or advancement of social rank within the group. Previous accounts of within‐group lethal violence concern victims who were low‐ranking males; here we provide the first account of the killing of an incumbent alpha male by a coalition of adult males from the same community. We found no clear evidence that the alpha male's position was under threat during the months before the lethal attack: the male dominance hierarchy was highly stable, with low rates of male–male aggression, and there were no significant changes in social interactions (i.e. grooming and aggression) between the alpha male and the other adult males. Two of the four attackers were former alpha males and were the individuals with whom the victim appeared, in the period preceding his death, to be most strongly affiliated: his most frequent grooming partners and those with whom he spent most time in proximity. The lethal attack triggered a period of instability in the male hierarchy and was likely an opportunistic attempt to seize alpha status by the third‐ranking male.
    • Social instability raises the stakes during social grooming among wild male chimpanzees

      Kaburu, Stefano S. K.; Newton-Fisher, Nicholas E. (Elsevier, 2013-07-22)
      Explaining cooperative behaviour is a fundamental issue for evolutionary biology. The challenge for any cooperative strategy is to minimize the risks of nonreciprocation (cheating) in interactions with immediate costs and delayed benefits. One of a variety of proposed strategies, the raise-the-stakes (RTS) strategy, posits that individuals establish cooperation by increasing investment across interactions from an initial interaction. This model has received little quantitative support, however, probably because individuals of many social species engage in repeated interactions from a young age. In some situations, however, such as following conflicts, after prolonged absences or during social instability, established relationships may become unreliable predictors of future behaviour, creating an environment for RTS. We investigated grooming interactions among wild male chimpanzees, Pan troglodytes, testing RTS in these specific contexts. We found evidence to support the view that male chimpanzees employed RTS during social instability, but not under the other conditions. However, we also found that the duration of episodes (discrete parcels) of grooming was negatively related to aggression risk and in consequence suggest that the patterning of grooming interactions indicative of RTS was less to do with preventing cheating, and more to do with avoiding the elevated risks of intramale aggression during the period of social instability. We interpret the apparent support for RTS in our data as a by-product of the way chimpanzees cope with fluctuating (here, elevated then diminishing) risks of aggression. We suggest that social instability raises the stakes for grooming by creating a more hazardous marketplace in which to trade.
    • Dominance rank and self-scratching among wild female Barbary macaques (Macaca sylvanus)

      Kaburu, Stefano S. K; Maclarnon, Ann; Majolo, Bonaventura; Quarro, Mohamed; Semple, Stuart (BioOne, 2012-04-01)
      Measuring rates of self-scratching provides a powerful index of anxiety in non-human primates, and investigating the relationship between self-scratching and dominance rank can shed light on the ‘emotional costs’ of holding different positions in the hierarchy. Here we explored the relationship between self-scratching rates and rank in wild adult female Barbary macaques (Macaca sylvanus) in Morocco. We found a significant correlation between rank and females’ mean self-scratching rates over the study period, with subordinates showing higher rates of self-scratching. Analysis of temporal variation in females’ self-scratching rates indicated that while these rates were related to measures of both grooming and aggression, the relationship between rank and self-scratching remained significant even after controlling for these effects. Our data suggest that lower ranked female Barbary macaques suffer higher levels of anxiety than more dominant individuals, and hence that there is an emotional cost associated with having low social status in this species.
    • Web browser artefacts in private and portable modes: a forensic investigation

      Flowers, Cassandra; Mansour, Ali; Al-Khateeb, Haider M. (Inderscience, 2016-03-15)
      Web browsers are essential tools for accessing the internet. Extra complexities are added to forensic investigations when recovering browsing artefacts as portable and private browsing are now common and available in popular web browsers. Browsers claim that whilst operating in private mode, no data is stored on the system. This paper investigates whether the claims of web browsers discretion are true by analysing the remnants of browsing left by the latest versions of Internet Explorer, Chrome, Firefox, and Opera when used in a private browsing session, as a portable browser, and when the former is running in private mode. Some of our key findings show how forensic analysis of the file system recovers evidence from IE while running in private mode whereas other browsers seem to maintain better user privacy. We analyse volatile memory and demonstrate how physical memory by means of dump files, hibernate and page files are the key areas where evidence from all browsers will still be recoverable despite their mode or location they run from.
    • A novel mechanism for the anti-cancer activity of aspirin and salicylates

      Bashir, Asma'u I.J.; Kankipati, Chandras S.; Jones, Sarah; Newman, Robert M.; Safrany, Stephen T.; Perry, Christopher J.; Nicholl, Iain D. (Spandidos Publications Ltd, 2019-01-29)
      Epidemiological studies indicate that long-term aspirin usage reduces the incidence of colorectal cancer (CRC) and may protect against other non-CRC associated adenocarcinomas, including oesophageal cancer. A number of hypotheses have been proposed with respect to the molecular action of aspirin and other non‑steroidal anti‑inflammatory drugs in cancer development. The mechanism by which aspirin exhibits toxicity to CRC has been previously investigated by synthesising novel analogues and derivatives of aspirin in an effort to identify functionally significant moieties. Herein, an early effect of aspirin and aspirin-like analogues against the SW480 CRC cell line was investigated, with a particular focus on critical molecules in the epidermal growth factor (EGF) pathway. The present authors proposed that aspirin, diaspirin and analogues, and diflunisal (a salicylic acid derivative) may rapidly perturb EGF and EGF receptor (EGFR) internalisation. Upon longer incubations, the diaspirins and thioaspirins may inhibit EGFR phosphorylation at Tyr1045 and Tyr1173. It was additionally demonstrated, using a qualitative approach, that EGF internalisation in the SW480 cell line may be directed to endosomes by fumaryldiaspirin using early endosome antigen 1 as an early endosomal marker and that EGF internalisation may also be perturbed in oesophageal cell lines, suggestive of an effect not only restricted to CRC cells. Taken together and in light of our previous findings that the aspirin-like analogues can affect cyclin D1 expression and nuclear factor-κB localisation, it was hypothesized that aspirin and aspirin analogues significantly and swiftly perturb the EGFR axis and that the protective activity of aspirin may in part be explained by perturbed EGFR internalisation and activation. These findings may also have implications in understanding the inhibitory effect of aspirin and salicylates on wound healing, given the critical role of EGF in the response to tissue trauma.
    • Advancing lean implementation within a construction supply chain

      Saini, Mandeep; Arif, Mohammed (University of Wolverhampton, 2018-12-19)
      This investigation leads to critical recommendations for advancing the Small and Medium Enterprises (SMEs) for lean implementation within a Construction Supply Chain (CSC). The findings suggest that implementing Lean within a CSC requires a similar effort at different levels (Organisational and Process) of Supply Chain. This study presents essential recommendations that would ensure smooth flow of Lean implementation at all levels of a CSC. This paper draws upon relevant literature, sixty-three surveys and interviews with four professionals working on the frontlines and emphasises on the issues that hinder the SMEs engagement and contribution to Lean within Construction Supply Chain. Moreover, this involved respondents from Tier 1, Tier 2, and Tier 3 of a CSC that includes clients, executives, consultants, and other managers, who are directly involved in the Lean implementation in construction projects. This paper adds value to the existing knowledge of Lean implementation in a CSC and SMEs. This study is original in terms of establishing the recommendation to lean implementation in a CSC.
    • Challenges to transferring and sharing of tacit knowledge within a construction supply chain

      Saini, Mandeep; Arif, Mohammed; Kulonda, Dennis J. (Emerald, 2019-01-17)
      Purpose – This paper investigates the potential challenges that hinder the effective transfer and sharing of Tacit Knowledge (Knowledge Communication) within a construction supply chain (CSC). Design/Methodology/Approach – This study identifies six challenges (through literature review) with fifteen positive correlations between them. Quantitative methodology is employed to validate those challenges and correlations between challenges. Firstly, data is collected through semi-structured e-survey questionnaire. Afterwards, a Frequency and Kruskal-Wallis H test is run for initial validation of identified challenges. A correlation analysis is used to highlight the taxonomic relations between those challenges. Finally, the study establishes the rank order of the first and following challenges. Findings – This study highlights that traditional ways of working with construction organisations are the predominant challenge that hinders effective transferring and sharing of Tacit Knowledge. The cause of challenges is the fragmented nature of CSC. Also, it brings out the correlation between those challenges. The study draws the conclusion and recommendation to implement Knowledge Communication (KC) within a CSC. Originality/Value – The study highlights the challenges that hinder KC in a construction process of a CSC. It establishes that the fragmented nature of the construction sector is not the first challenge that hinders implementation of transferring and sharing of Tacit Knowledge but somewhat traditional organisation structures and working processes. This is the first paper that investigates and tests the challenges in four dimensions and establishes the rank order of challenges with crucial distinction in a KC approach within a CSC. Conclusion – This study identifies the rank order of challenges. It also discusses the implementation of KC within a CSC. It reflects the current understanding of KC in the construction sector and pinpoints the contribution of this study in academia and practice. Keywords - Construction Supply Chains, Knowledge Management, Tacit Knowledge, Transferring and Sharing Tacit Knowledge, Knowledge Communication in Construction Processes, Knowledge Communication
    • Trading or coercion? variation in male mating strategies between two communities of East African chimpanzees

      Kaburu, Stefano S. K; Newton-Fisher, Nicholas E. (Springer, 2015-04-08)
      Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolize access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (Pan troglodytes schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading—of grooming for mating—by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism–egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees’ willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness.
    • The effect of malondialdehyde is modified by simian virus 40 transformation in human lung fibroblast cells

      Yates, Sally Ann; Murphy, Mark F.; Moore, Sharon Ann (Elsevier, 2019-01-15)
      The effects of malondialdehyde (MDA), a product of oxidative stress, on normal lung fibroblast cells (MRC5) and transformed c ells (MRC5 SV2) showed differing responses between the two cell lines. MRC5 cells showed lower viability at low MDA concentrations (<250 µM) but had better viability at higher concentrations than the transformed cells. Both cell lines showed an increase in the number of micronuclei, nuclear size and a relocation of p53 to the nucleus with increasing MDA. The expression of p53 was higher in the MRC5 cells at 24 h; 2-8 fold induction vs 1-2.5 fold in the MRC5 SV2 cells, but reduced to almost zero at 48 h in the MRC5 cells. Mutation sequencing of the PCR products of a 689 bp region (residues 4640-5328) of the TP53 gene revealed MRC5 had more mutations than MRC5 SV2 cells (n = 21 and 11 respectively) and that they were predominantly insertions (MRC5 81%, MRC5 SV2 100%). A common mutation was observed in both cell lines; a G insertion at residue 4724 (n = 7) which could prove to be a mutational hotspot. These results indicate that the transformed cells are slower to respond to oxidative stress and/or mutagenic compounds. The mutation spectrum of predominantly frameshift mutations (insertions) suggests that oxidative stress plays a minimal role in smoking related lung cancer, but could be of greater importance to other lung diseases and cancer caused by exposures such as passive smokers, passive vapers and atmospheric pollutants.
    • First-time rhesus monkey mothers, and mothers of sons, preferentially engage in face-to-face interactions with infants

      Dettmer, Amanda M.; Kaburu, Stefano S. K; Byers, Kristen L.; Murphy, Ashley M.; Soneson, Emma; Wooddell, Lauren J.; Suomi, Stephen J. (Wiley, 2015-11-18)
      Face-to-face interactions between mothers and infants occur in both human and non-human primates, but there is large variability in the occurrence of these behaviors and the reason for this variability remains largely unexplored. Other types of maternal investment have been shown to be dependent on infant sex (e.g. milk production and maternal responsiveness) and maternal experience (e.g. symmetrical communication). Thus, we sought to determine whether variability in face-to-face interactions, that is, mutual gazing (MG), which are hypothesized to be important for later socio-cognitive development, could be explained by these variables. We studied 28 semi-free ranging rhesus monkey (Macaca mulatta) mother-infant dyads (6 primiparous; 12 male infants) born and reared at the Laboratory of Comparative Ethology field station at the NIH Animal Center in Poolesville, MD, across the first 90 postnatal days. Infant sex (i.e. male) was a significant predictor of maternal grooming (β ± SE = 0.359 ± 0.164, Z = 2.19, P = 0.029) whereas both parity (i.e. first time mothers) and infant sex (i.e. male) significantly predicted MG (parity: β ± SE = -0.735 ± 0.223, Z = -3.30, P < 0.001; infant sex: β ± SE = 0.436 ± 0.201, Z = 2.17, P = 0.029). Separation from the mother (outside of arm's reach) was not influenced by parity or infant sex. Together with existing literature, these findings point toward differential maternal investment for sons versus daughters. Mothers may be investing differentially in sons, behaviorally, to ensure their future social competence and thus later reproductive success. Collectively, our findings add to the literature that is beginning to identify early life experiences that may lead to sex differences in neurological and behavioral development.
    • Bystanders, parcelling, and an absence of trust in the grooming interactions of wild chimpanzees

      Kaburu, Stefano S. K.; Newton-Fisher, Nicholas E. (Nature, 2016-01-06)
      The evolution of cooperation remains a central issue in socio-biology with the fundamental problem of how individuals minimize the risks of being short-changed (‘cheated’) should their behavioural investment in another not be returned. Economic decisions that individuals make during interactions may depend upon the presence of potential partners nearby, which offers co operators a temptation to defect from the current partner. The parcelling model posits that donors subdivide services into parcels to force cooperation, and that this is contingent on opportunities for defection; that is, the presence of bystanders. Here we test this model and the effect of bystander presence using grooming interactions of wild chimpanzees. We found that with more bystanders, initiators gave less grooming at the beginning of the bout and were more likely to abandon a grooming bout, while bouts were less likely to be reciprocated. We also found that the groomer’s initial investment was not higher among frequent groomers or stronger reciprocators, suggesting that contrary to current assumptions, grooming decisions are not based on trust, or bonds, within dyads. Our work highlights the importance of considering immediate social context and the influence of bystanders for understanding the evolution of the behavioural strategies that produce cooperation.
    • Neonatal face-to-face interactions promote later social behaviour in infant rhesus monkeys

      Dettmer, Amanda M.; Kaburu, Stefano S. K.; Simpson, Elizabeth A.; Paukner, Annika; Sclafani, Valentina; Byers, Kristen L.; Murphy, Ashley M.; Miller, Michelle; Marquez, Neal; Miller, Grace M.; Suomi, Stephen J.; Ferrari, Pier F. (Nature, 2016-06-14)
      In primates, including humans, mothers engage in face-to-face interactions with their infants, with frequencies varying both within and across species. However, the impact of this variation in face-to-face interactions on infant social development is unclear. Here we report that infant monkeys (Macaca mulatta) who engaged in more neonatal face-to-face interactions with mothers have increased social interactions at 2 and 5 months. In a controlled experiment, we show that this effect is not due to physical contact alone: monkeys randomly assigned to receive additional neonatal face-to-face interactions (mutual gaze and intermittent lip-smacking) with human caregivers display increased social interest at 2 months, compared with monkeys who received only additional handling. These studies suggest that face-to-face interactions from birth promote young primate social interest and competency.
    • Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque

      Wooddell, Lauren J.; Rosenberg, Kendra L; Kaburu, Stefano; Meyer, Jerrold S.; Suomi, Stephen J.; Dettmer, Amanda M. (Plos, 2016-06-08)
      In many species, the loss of alpha matriarchs is associated with a number of negative outcomes such as troop fission, eviction, wounding, and reduced vitality. However, whether the dramatic consequences of their loss are due to their role as an old experienced figure or to their alpha status remains unclear. In a retrospective study, we tested that in a semi-free ranging colony of rhesus macaques (Macaca mulatta), the removal of a non-alpha matriarch, who had a large set of kin, led to changes in behavior and physiological stress within her matriline. Following her removal, her matriline increased in aggression, vigilance, and social grooming. Additionally, hierarchical stability, measured by levels of rank changes, decreased within her matriline, and levels of intense aggression by high-ranking animals were more frequent, as well as matrilineal wounding. Although ordinal rank was positively associated with higher chronic hair cortisol concentrations (HCCs) in the months before the matriarch’s removal, following her removal, only those who experienced large increases in rank within her matriline displayed higher HCCs. Changes in matrilineal stability, aggression, behavior, and HCCs within the other two matrilines in the troop were not evident, although caution is needed due to the small sample sizes. We conclude that the removal of the non-alpha matriarch led to matrilineal instability, characterized by higher levels of aggression and subsequent vigilance, rank changes, physiological stress, and grooming. We suggest that non-alpha matriarchs with a large number of kin and social support can be integral to the stability of matrilines.