The predictive validity of the Living Goods selection tools for community health workers in Kenya : cohort study

Background Ensuring that selection processes for Community Health Workers (CHWs) are effective is important due to the scale and scope of modern CHW programmes. However they are relatively understudied. While community involvement in selection should never be eliminated entirely, there are other complementary methods that could be used to help identify those most likely to be high-performing CHWs. This study evaluated the predictive validity of three written tests and two individual sections of a one-to-one interview used for selection into CHW posts in eight areas of Kenya. Methods A cohort study of CHWs working for Living Goods in eight local areas of Kenya was undertaken. Data on the selection scores, post-training assessment scores and subsequent on-the-job performance (number of household and pregnancy registrations, number of child assessments, proportion of on-time follow-ups and value of goods sold) were obtained for 547 CHWs. Kendall’s tau-b correlations between each selection score and performance outcome were calculated. Results None of the correlations between selection scores and outcomes reached the 0.3 threshold of an “adequate” predictor of performance. Correlations were higher for the written components of the selection process compared to the interview components, with some small negative correlations found for the latter. Conclusions If the measures of performance included in this study are considered critical, then further work to develop the CHW selection tools is required. This could include modifying the content of both tools or increasing the length of the written tests to make them more reliable, for if a test is not reliable then it cannot be valid. Other important outcomes not included in this study are retention in post and quality of care. Other CHW programme providers should consider evaluating their own selection tools in partnership with research teams

Case study of a method of development of a selection process for community health workers in sub-Saharan Africa

Background Choosing who should be recruited as a community health worker (CHW) is an important task, for their future performance partly depends on their ability to learn the required knowledge and skills, and their personal attributes. Developing a fair and effective selection process for CHWs is a challenging task, and reports of attempts to do so are rare. This paper describes a five-stage process of development and initial testing of a CHW selection process in two CHW programmes, one in Malawi and one in Ghana, highlighting the lessons learned at each stage and offering recommendations to other CHW programme providers seeking to develop their own selection processes. Case presentation The five stages of selection process development were as follows: (1) review an existing selection process, (2) conduct a job analysis, (3) elicit stakeholder opinions, (4) co-design the selection process and (5) test the selection process. Good practice in selection process development from the human resource literature and the principles of co-design were considered throughout. Validity, reliability, fairness, acceptability and feasibility—the determinants of selection process utility—were considered as appropriate during stages 1 to 4 and used to guide the testing in stage 5. The selection methods used by each local team were a written test and a short interview. Conclusions Working with stakeholders, including CHWs, helped to ensure the acceptability of the selection processes developed. Expectations of intensiveness—in particular the number of interviewers—needed to be managed as resources for selection are limited, and CHWs reported that any form of interview may be stressful. Testing highlighted the importance of piloting with CHWs to ensure clarity of wording of questions, interviewer training to maximise inter-rater reliability and the provision of guidance to applicants in advance of any selection events. Trade-offs between the different components of selection process utility are also likely to be required. Further refinements and evaluation of predictive validity (i.e. a sixth stage of development) would be recommended before roll-out

Decoupling Functional and Morphological Convergence, the Study Case of Fossorial Mammalia

Morphological similarity between biological structures in phylogenetically distant species is usually regarded as evidence of convergent evolution. Yet, phenotypic similarity is not always a sign of natural selection acting on a particular trait, therefore adaptation to similar conditions may fail to generate convergent lineages. Herein we tested whether convergent evolution occurred in the humerus of fossorial mammals, one of the most derived biological structures among mammals. Clades adapting to digging kinematics possess unusual, by mammalian standards, humeral shapes. The application of a new, computationally fast morphological test revealed a single significant instance of convergence pertaining to the Japanese fossorial moles (Mogera) and the North-American fossorial moles (Scalopini). Yet, the pattern only manifests when trade-off performance data (derived from finite element analysis) are added to shape data. This result indicates that fossorial mammals have found multiple solutions to the same adaptive challenge, independently moving around multiple adaptive peaks. This study suggests the importance of accounting for functional trade-off measures when studying morpho-functional convergence. We revealed that fossorial mammals, a classic example of convergent evolution, evolved multiple strategies to exploit the subterranean ecotope, characterized by different functional trade-offs rather than converging toward a single adaptive optimum

Revising ethical guidance for the evaluation of programmes and interventions not initiated by researchers

Public health and service delivery programmes, interventions and policies (collectively, ‘programmes’) are typically developed and implemented for the primary purpose of effecting change rather than generating knowledge. Nonetheless, evaluations of these programmes may produce valuable learning that helps determine effectiveness and costs as well as informing design and implementation of future programmes. Such studies might be termed ‘opportunistic evaluations’, since they are responsive to emergent opportunities rather than being studies of interventions that are initiated or designed by researchers. However, current ethical guidance and registration procedures make little allowance for scenarios where researchers have played no role in the development or implementation of a programme, but nevertheless plan to conduct a prospective evaluation. We explore the limitations of the guidance and procedures with respect to opportunistic evaluations, providing a number of examples. We propose that one key missing distinction in current guidance is moral responsibility: researchers can only be held accountable for those aspects of a study over which they have control. We argue that requiring researchers to justify an intervention, programme or policy that would occur regardless of their involvement prevents or hinders research in the public interest without providing any further protections to research participants. We recommend that trial consent and ethics procedures allow for a clear separation of responsibilities for the intervention and the evaluation

Scavenging in Northwestern Europe: A Survey of UK Police Specialist Search Officers

Physical search methods used by police specialist searchers are based on counter-terrorism methods and not on the search and recovery of outdoor surface deposited human remains, nevertheless these methods are applied to scenes involving human remains. Additionally, there is limited published forensic literature within Northwestern Europe on the potential taphonomic agents within this region that are capable of modifying human remains through scavenging, scattering and removal. The counter-terrorism basis in physical search methods and the gap in published forensic literature regarding scavenging in this region can potentially impede searchers’ abilities to adapt physical search methods to their full efficiency in the search and recovery of scavenged human remains. This paper analysed through a questionnaire survey of 111 police specialist searchers, within the U.K., the impact of animal scavenging on the search and recovery of human remains.According to questionnaire respondents’ experiences and knowledge, the occurrence of scavenging at scenes in which respondents took part in a physical search for human remains was common (63.46%,n= 66) and happened most frequently with surface deposits (68.25%,n= 43). Scavenging resulted in the recovery of incomplete sets of remains (59.79%, n= 58) and influenced search perimeters (58.33%, n= 35). Scavenging also affected recovery rates at scene searches (80.43%,n= 74) that included the use of cadaver dogs with police handlers. The impact scavengers within this region have on different crime scene scenarios and search methods is not reflected in current published literature or search standards

The Effects of Biting and Pulling on the Forces Generated during Feeding in the Komodo Dragon (Varanus komodoensis)

In addition to biting, it has been speculated that the forces resulting from pulling on food items may also contribute to feeding success in carnivorous vertebrates. We present an in vivo analysis of both bite and pulling forces in Varanus komodoensis, the Komodo dragon, to determine how they contribute to feeding behavior. Observations of cranial modeling and behavior suggest that V. komodoensis feeds using bite force supplemented by pulling in the caudal/ventrocaudal direction. We tested these observations using force gauges/transducers to measure biting and pulling forces. Maximum bite force correlates with both body mass and total body length, likely due to increased muscle mass. Individuals showed consistent behaviors when biting, including the typical medial-caudal head rotation. Pull force correlates best with total body length, longer limbs and larger postcranial motions. None of these forces correlated well with head dimensions. When pulling, V. komodoensis use neck and limb movements that are associated with increased caudal and ventral oriented force. Measured bite force in Varanus komodoensis is similar to several previous estimations based on 3D models, but is low for its body mass relative to other vertebrates. Pull force, especially in the ventrocaudal direction, would allow individuals to hunt and deflesh with high success without the need of strong jaw adductors. In future studies, pull forces need to be considered for a complete understanding of vertebrate carnivore feeding dynamics

A method for mapping morphological convergence on three-dimensional digital models: the case of the mammalian sabre-tooth

Morphological convergence can be assessed using a variety of statistical methods. None of the methods proposed to date enable the visualization of convergence. All are based on the assumption that the phenotypes either converge, or do not. However, between species, morphologically similar regions of a larger structure may behave differently. Previous approaches do not identify these regions within the larger structures or quantify the degree to which they may contribute to overall convergence. Here, we introduce a new method to chart patterns of convergence on three-dimensional models using the R function conv.map. The convergence between pairs of models is mapped onto them to visualize and quantify the morphological convergence. We applied conv.map to a well-known case study, the sabre-tooth morphotype, which has evolved independently among distinct mammalian clades from placentals to metatherians. Although previous authors have concluded that sabre-tooths kill using a stabbing ‘bite’ to the neck, others have presented different interpretations for specific taxa, including the iconic Smilodon and Thylacosmilus. Our objective was to identify any shared morphological features among the sabre-tooths that may underpin similar killing behaviours. From a sample of 49 placental and metatherian carnivores, we found stronger convergence among sabre-tooths than for any other taxa. The morphological convergence is most apparent in the rostral and posterior parts of the cranium. The extent of this convergence suggests similarity in function among these phylogenetically distant species. In our view, this function is most likely to be the killing of relatively large prey using a stabbing bite. © 2021 The Authors. Palaeontology published by John Wiley & Sons Ltd on behalf of The Palaeontological Association

More Challenging Diets Sustain Feeding Performance: Applications Toward the Captive Rearing of Wildlife

The rescue and rehabilitation of young fauna is of substantial importance to conservation. However, it has been suggested that incongruous diets offered in captive environments may alter craniofacial morphology and hinder the success of reintroduced animals. Despite these claims, to what extent dietary variation throughout ontogeny impacts intrapopulation cranial biomechanics has not yet been tested. Here, finite element models were generated from the adult crania of 40 rats (n = 10 per group) that were reared on 4 different diet regimes and stress magnitudes compared during incisor bite simulations. The diets consisted of (1) exclusively hard pellets from weaning, (2) exclusively soft ground pellet meal from weaning, (3) a juvenile switch from pellets to meal, and (4) a juvenile switch from meal to pellets. We hypothesized that a diet of exclusively soft meal would result in the weakest adult skulls, represented by significantly greater stress magnitudes at the muzzle, palate, and zygomatic arch. Our hypothesis was supported at the muzzle and palate, indicating that a diet limited to soft food inhibits bone deposition throughout ontogeny. This finding presents a strong case for a more variable and challenging diet during development. However, rather than the "soft" diet group resulting in the weakest zygomatic arch as predicted, this region instead showed the highest stress among rats that switched as juveniles from hard pellets to soft meal. We attribute this to a potential reduction in number and activity of osteoblasts, as demonstrated in studies of sudden and prolonged disuse of bone. A shift to softer foods in captivity, during rehabilitation after injury in the wild for example, can therefore be detrimental to healthy development of the skull in some growing animals, potentially increasing the risk of injury and impacting the ability to access full ranges of wild foods upon release. We suggest captive diet plans consider not just nutritional requirements but also food mechanical properties when rearing wildlife to adulthood for reintroduction

Digital dissection and three-dimensional interactive models of limb musculature in the Australian estuarine crocodile (Crocodylus porosus)

Digital dissection is a relatively new technique that has enabled scientists to gain a better understanding of vertebrate anatomy. It can be used to rapidly disseminate detailed, threedimensional information in an easily accessible manner that reduces the need for destructive, traditional dissections. Here we present the results of a digital dissection on the appendicular musculature of the Australian estuarine crocodile (Crocodylus porosus). A better understanding of this until now poorly known system in C. porosus is important, not only because it will expand research into crocodilian locomotion, but because of its potential to inform muscle reconstructions in dinosaur taxa. Muscles of the forelimb and hindlimb are described and three-dimensional interactive models are included based on CT and MRI scans as well as fresh-tissue dissections. Differences in the arrangement of musculature between C. porosus and other groups within the Crocodylia were found. In the forelimb, differences are restricted to a single tendon of origin for triceps longus medialis. For the hindlimb, a reduction in the number of heads of ambiens was noted as well as changes to the location of origin and insertion for iliofibularis and gastrocnemius externus