Evaluating the impact of a novel behavioural science informed animation upon breast cancer screening uptake: protocol for a randomised controlled trial.

BACKGROUND: Breast cancer screening is estimated to save 1300 lives annually in the United Kingdom. Despite this, uptake of invitations has fallen over the past decade. Behavioural science-informed interventions addressing the determinants of attendance behaviour have shown variable effectiveness. This may be due to the narrow repertoire of techniques trialled, and the difficulties of implementation at a population-scale. The aim of this study is to evaluate the impact on breast screening uptake of a novel behavioural video intervention which can contain more complex combinations of behavioural change techniques. METHODS: A 3-armed randomised controlled trial will be undertaken in London comparing the impact of (1) the usual care SMS reminder, to (2) a behavioural plain text SMS reminder and (3) a novel video sent as a link within the behavioural plain text SMS reminder. A total of 8391 participants (2797 per group) will be allocated to one of the three trial arms using a computer randomisation process, based upon individuals' healthcare identification numbers. The novel video has been co-designed with a diverse range of women to overcome the barriers faced by underserved communities and the wider population. The behavioural SMS content has also been co-designed through the same process as the video. Messages will be sent through the current reminder system used by the London screening programmes, with reminders 7 days and 2 days prior to a timed appointment. The primary outcome is attendance at breast cancer screening within 3 months of the initial invitation. Secondary outcomes will include evaluating the impact of each message amongst socio-demographic groups and according to the appointment type e.g. first invitation or recall. DISCUSSION: In addition to general declining trends in attendance, there is also concern of increasing healthcare inequalities with breast cancer screening in London. The current novel intervention, designed with underserved groups and the general population, incorporates several behavioural techniques to overcome the barriers to attendance. Understanding its potential impact in a real-world setting therefore may provide significant information on how to address reducing attendance and healthcare disparities. TRIAL REGISTRATION: This study was registered on ClinicalTrials.gov ( NCT05395871 ) on the 27th May 2022.

Behavioral economics informed message content in text message reminders to improve cervical screening participation: Two pragmatic randomized controlled trials.

The objective of the reported research was to assess the impact of text message (SMS) reminders and their content on cervical screening rates. Women invited for cervical screening in Northwest London from February-October 2015 were eligible. 3133 women aged 24-29 (Study 1) were randomized (1, 1) to 'no SMS' (control), or a primary care physician (PCP) endorsed SMS (SMS-PCP). 11,405 women aged 30-64 (Study 2), were randomized (1, 1:1:1:1:1:1) to either: no SMS, an SMS without manipulation (SMS), the SMS-PCP, an SMS with a total or proportionate social norm (SMS-SNT or SMS-SNP), or an SMS with a gain-framed or loss-framed message (SMS-GF and SMS-LF). The primary outcome was participation at 18 weeks. In Study 1 participation was significantly higher in the SMS-PCP arm (31.4%) compared to control (26.4%, aOR, 1.29, 95%CI: 1.09-1·51; p = 0.002). In Study 2 participation was highest in the SMS-PCP (38.4%) and SMS (38.1%) arms compared to control (34.4%), (aOR: 1.19, 95%CI: 1.03-1.38; p = 0.02 and aOR: 1.18, 95%CI: 1.02-1.37; p = 0.03, respectively). The results demonstrate that behavioral SMSs improve cervical screening participation. The message content plays an important role in the impact of SMS. The results from this trial have already been used to designing effective policy for cervical cancer screening. The NHS Cervical Screening Programme started running a London-wide screening SMS campaign which was based on the cervical screening trial described here. According to figures published by Public Health England, after six months attendance increased by 4.8%, which is the equivalent of 13,400 more women being screened at 18 weeks.

Can we see what is invisible? The role of MRI in the evaluation and management of patients with pathological nipple discharge.

INTRODUCTION: The aim of this study was to determine the ability of MRI to identify and assess the extent of disease in patients with pathological nipple discharge (PND) with an occult malignancy not evident on standard pre-operative evaluation with mammography and ultrasound. METHODS: Patients presenting to the breast unit of Imperial College Healthcare NHS Trust between December 2009 and December 2018 with PND and normal imaging were enrolled in the study. Pre-operative bilateral breast MRI was performed in all patients as part of our protocol and all patients were offered diagnostic microdochectomy. RESULTS: A total of 82 patients fulfilled our selection criteria and were enrolled in our study. The presence of an intraductal papilloma (IDP) was identified as the cause of PND in 38 patients (46.3%), 14 patients had duct ectasia (DE-17%) and 5 patients had both an IDP and DE. Other benign causes were identified in 11 patients (13.4%). Despite normal mammography and ultrasound a malignancy was identified in 14 patients (17%). Eleven patients had DCIS (13.4%), two had invasive lobular carcinoma and one patient had an invasive ductal carcinoma. The sensitivity of MRI in detecting an occult malignancy was 85.71% and the specificity was 98.53%. The positive predictive value was 92.31% and the negative predictive value was 97.1%. CONCLUSIONS: Although a negative MRI does not exclude the presence of an occult malignancy the high sensitivity and specificity of this diagnostic modality can guide the surgeon and alter the management of patients with PND.

Reevaluation of the body mass estimate for the KNM-ER 5428 Homo erectus talus.

OBJECTIVES: In this study, we reexamined the body mass estimate for the Homo erectus specimen KNM-ER 5428 based on talus dimensions. Previous estimates of >90 kg for this fossil are large in comparison to body mass estimates for other H. erectus specimens. MATERIALS AND METHODS: The study sample consisted of tali and femora of 132 modern cadaver males from a documented body mass skeletal collection. We recorded the talus trochlear mediolateral (TTML) breadth and femoral head diameter (FHD) for each modern human specimen, and obtained KNM-ER 5428's TTML values from the literature. We developed regression formulae based on TTML using the body mass estimated from FHD for the entire human sample and for known body masses from a normal-BMI subsample, and then used these formulae to calculate body mass for KNM-ER 5428. In addition, we examined the range of body masses for individuals with TTML measurements comparable to KNM-ER 5428. RESULTS: The body masses of normal-BMI individuals with a TTML ≥32.3 mm (the smaller of the two fossil measurements from the literature) ranged between 60.3 and 86.2 kg and averaged 72.3 kg. The body masses of normal-BMI individuals with a TTML ≥33.7 mm (the larger measurement) ranged between 63.5 and 86.2 kg with a mean of 73.6 kg. The correlations between TTML and body mass are moderate. Revised body mass point estimates for KNM-ER 5428 ranged between 69.2 and 81.6 kg based on TTML, and average 70.5 and 76.0 kg. DISCUSSION: Results suggest previously published body mass estimates of KNM-ER 5428's are too large. Its body mass was likely between 70 and 76 kg rather than >90 kg.

The effect of ontogeny on estimates of KNM-WT 15000's adult body size.

The Homo erectus specimen KNM-WT 15000 has played a critical role in our understanding of body size evolution. New interpretations suggest that KNM-WT 15000 had a younger age-at-death and a more rapid ontogenetic trajectory than previously suggested. Recent fossil discoveries and new interpretations suggest a wide range of body size and shape variation in H. erectus. Based on these new insights, we argue that KNM-WT 15000's adult stature and body mass could have been much smaller than has been traditionally presented in the literature. Using chimpanzee and modern human growth trajectories, we bracketed the range of possibilities for KNM-WT 15000's adult body size between 160.0 and 177.7 cm (5'3″-5'10″) for stature and 60.0 and 82.7 kg (132-182 lbs.) for body mass. These estimates put KNM-WT 15000 near the mean rather than among the largest known H. erectus specimens.

Reducing Blood Culture Contaminations in the Emergency Department: It Takes a Team.

UNLABELLED: Healthcare providers rely heavily on blood culture results for developing the patient's plan of care. Contaminated blood cultures can lead to unnecessary treatment, unnecessary hospitalization, and an increase in the patient's length of stay. There was a significant increase in our monthly blood culture contamination rates, over a 3 month period of time, which exceeded a recommended standard of <3%, as high as 4.35%. Given the negative impact this could have on patient outcomes, a quality improvement project was developed in order to ensure delivery of the highest quality of care. METHODS: We reviewed the literature to identify best practices related to blood culture specimen collection and incorporated strategies that proved to be effective in overcoming barriers similar to ours. We also used strategies that were tailored to meet our specific needs. Our plan included targeting environmental and skin contaminates, teamwork, education and feedback. RESULTS: During the 8 week pilot, the monthly contamination rates were 1.96% and 0.3%, respectively. Subsequent data over 1 year revealed the contamination rates ranged from 0.2% to 1.51%, with a mean of 0.87%. DISCUSSION: The results show that reducing blood culture contamination rates through the use of a structured plan and teamwork is feasible in the fast-paced emergency department. The commitment from our team was considered the most valuable asset and strategy. Developing a plan that is evidence-based and feasible in the fast paced Emergency Department can help ensure the delivery of high quality care.

Surveillance of probably benign (BI-RADS 3) lesions in mammography: what is the right follow-up protocol?

BI-RADS-3 is a category in mammography for probably benign lesions and for which periodic follow-up with repeat imaging is recommended. At our institution repeated mammograms are performed at 6, 12, 18, and 24 months. The purpose of this study was to assess the significance of 18-month mammogram for evaluation of BI-RADS-3 lesions. Following IRB approval, electronic medical records and picture archiving and communications system were used to review 121,862 consecutive mammograms between February, 2002-May, 2009. A total of 8,400 patients with BI-RADS-3 mammograms were identified. Of these, 7,632 patients were followed until completion of 24 month mammogram or biopsy following an upgrade in their BI-RADS status. Over the follow-up, 197 patients received an upgrade in their BI-RADS status of which 179 were biopsied. Histopathologic results were reviewed. The majority of the BI-RADS-3 lesions were upgraded at 6-month mammogram (n = 150, 76.1%) followed by 32 (16.2%), 11 (5.6%), and 4 (2.0%) at 12, 18, and 24 month mammograms respectively. Thirty-four of 179 upgraded and biopsied lesions were found to be malignant. From these 27 (79.4%), 3 (8.8%), 3 (8.8%), and 1 (2.9%) lesions were identified at 6, 12, 18, and 24 month mammograms respectively. At the 18-month mammogram 3/7,632 lesions (0.04%) were found to be malignant. The vast majority of malignant lesions (88.2%) were detected within the first 12-months of follow-up. Only three of 179 biopsies (1.7%) were malignant at 18-month follow-up. Based on those results a 6-, 12-, and 24-month follow-up protocol for BI-RADS-3 lesions is sufficient.

Temporal trends in femoral diaphyseal torsional asymmetry among the Arikara associated with postural behavior.

Average femoral torsion has been reported to differ among populations, and several studies have observed a relatively high prevalence of femoral anteversion asymmetry in Native Americans, especially females. This study investigates sexual dimorphism and temporal trends in femoral torsional asymmetry among the Arikara from the seventeenth to the early nineteenth century. To establish if there are population differences, femoral torsion was first measured using a direct method on a diverse comparative sample of Native Americans from the Southwest, Midwest, and Great Plains as well as American Whites and Blacks. To examine temporal trends among the Arikara, femoral torsion was examined using the orientation of the maximum bending rigidity at subtrochanteric in 154 females and 164 males from three temporal variants of the Arikara Coalescent tradition. There is significant sexual dimorphism in femoral torsional directional and absolute asymmetry among most Native American samples, but not among American Whites and Blacks. Among the Arikara there is significant sexual dimorphism in femoral torsional asymmetry in all three temporal variants, and asymmetry in femoral torsional asymmetry increased significantly from the protohistoric to the early historic period among females. The increased femoral torsional asymmetry is likely associated with a common side-sitting posture observed in historic photographs of Great Plains females. Historic Arikara females may have habitually sat in this compulsory position for extended periods while conducting domestic chores. The dramatic change from the protohistoric to historic period suggests a cultural change in sitting posture among females that was widespread across the Northern Plains.

An Introduction to The Orbital Buttresses.

Facial buttresses are supportive bony structures of the facial skeleton that form a thick, strong, and protective framework for the face. Surgical fixation may be required to restore morphology and function when damage to these buttresses occurs. We sought to determine if, similar to buttresses of the facial skeleton, buttresses of the internal orbit exist. Hence, we analyzed 10 human cadaver skulls imaged by microcomputed tomography (micro-CT). Image processing and thickness/heat mapping were performed using Avizo and ImageJ softwares. After identifying the orbital buttresses, we reviewed CT scans of patients who had orbital fractures across three years to determine the frequency of fracture of the orbital buttresses. We identified 5 buttresses of the internal orbit: superomedial fronto-ethmoidal strut with the deep orbital buttress, inferomedial strut with the posterior ledge, inferior orbital fissure, sphenoid-frontal superolateral strut, and the sphenoid lip. The average threshold orbital buttress thickness was 1.36 (0.25) mm. A total of 1186 orbits of 593 individuals were analyzed for orbital buttress involvement. Orbital buttresses were spared in 770 (65%) orbits. The inferomedial strut with the posterior ledge was the most commonly fractured buttress in 14.4% of orbits (n=171), followed by the sphenoid strut and lip (66 [5.6%]). To our knowledge, this is the first description of the buttresses of the internal orbit. Orbital reconstruction for fracture repair or oncologic purposes requires the support of orbital buttresses. Understanding the anatomy of orbital buttresses is crucial for successful surgical planning, proper implant positioning, and restoration of function and appearance.

Macroscopic differences in adult human femora are linked to body mass index.

Bone functional adaptation is routinely invoked to interpret skeletal morphology despite ongoing debate regarding the limits of the bone response to mechanical stimuli. The wide variation in human body mass presents an opportunity to explore the relationship between mechanical load and skeletal response in weight-bearing elements. Here, we examine variation in femoral macroscopic morphology as a function of body mass index (BMI), which is used as a metric of load history. A sample of 80 femora (40 female; 40 male) from recent modern humans was selected from the Texas State University Donated Skeletal Collection. Femora were imaged using x-ray computed tomography (voxel size ~0.5 mm), and segmented to produce surface models. Landmark-based geometric morphometric analyses based on the Coherent Point Drift algorithm were conducted to quantify shape. Principal components analyses were used to summarize shape variation, and component scores were regressed on BMI. Within the male sample, increased BMI was associated with a mediolaterally expanded femoral shaft, as well as increased neck-shaft angle and decreased femoral neck anteversion angle. No statistically significant relationships between shape and BMI were found in the female sample. While mechanical stimulus has traditionally been applied to changes in long bong diaphyseal shape it appears that bone functional adaptation may also result in fundamental changes in the shape of skeletal elements.

Effects of obesity on talar micro- and macro-morphology.

The addition of information regarding obesity status to the forensic anthropological biological profile could significantly contribute to the identification of human skeletal remains since over 40% of the U.S. adult population is currently obese. This study examines the differences in talar shape and trabecular bone structure between obese and non-obese individuals. A sample of 20 obese and 20 non-obese divided evenly by sex was selected from the Texas State University Donated Skeletal Collection. Tali were imaged using x-ray computed tomography (voxel size: 28-38.7 µm). Image stacks were processed to produce binary images as well as trabecular thickness and spacing maps. Landmark-based geometric morphometric analyses were conducted to quantify shape variation. Shape coordinates were used to locate 100 geometrically homologous volumes of interest within each talus. Bone volume fraction, trabecular thickness, and trabecular spacing were extracted at each volume of interest. Within each sex, a one-way ANCOVA was used to determine if significant differences exist between obese and non-obese individuals in trabecular bone after controlling for age. The size of the talus as well as subtle aspects of shape were found to distinguish the sexes. The results further indicate that bone volume fraction significantly differs between obese and non-obese males. In females, bone volume fraction is correlated with age but does not differ between obese and non-obese. The study demonstrates that bone microstructure is a promising approach to estimating body mass or body mass index category but age effects diminish the potential for the talus to be used alone.

Sentinel lymph node biopsy for papillary thyroid cancer: 12 years of experience at a single institution.

BACKGROUND: The purpose of this study was to report our experience with sentinel lymph node dissection (SLND) for papillary thyroid carcinoma, to evaluate the feasibility and safety of the procedure, and to examine its potential utility as a guide for central neck dissection. MATERIALS AND METHODS: A retrospective chart review of patients undergoing total thyroidectomy from January 1998 thru January 2010 was conducted. Intratumoral injection of blue dye was used to identify the SLN. Central neck dissection (CND) was performed if the SLN was positive on frozen section. Locally advanced disease, previous thyroid surgery, or lymphadenopathy on preoperative imaging or intraoperative palpation were exclusion criteria. RESULTS: A total of 211 patients underwent SLN mapping. Of these, 165 patients (78%) were female and 46 (22%) were male. Also, 75 (36%) were ≤45 years of age, and 136 (64%) were older than 45. Tumors were ≤2.0 cm (T1) in 142 patients (67%), 2-4 cm (T2) in 35 patients (17%), >4 cm with minimal invasion (T3) in 32 patients (15%), and locally invasive (T4) in 2 patients (1%). At least 1 blue node was found in 192 patients (91%). Also, 47 patients had a positive SLN on frozen section, with an additional 24 node-positive patients on permanent section, for a total of 71 (37%). There were 43 patients (91%) who underwent central neck dissection; 26 (60%) had additional metastases. CONCLUSIONS: Sentinel lymphadenectomy for papillary thyroid carcinoma is feasible, safe, and can identify patients who may benefit from central neck dissection.

Just how strapping was KNM-WT 15000?

For over twenty years, the young, male Homo erectus specimen KNM-WT 15000 has been the focus of studies on growth and development, locomotion, size, sexual dimorphism, skeletal morphology, and encephalization, often serving as the standard for his species. Prior research on KNM-WT 15000 operates under the assumption that H. erectus experienced a modern human life history, including an adolescent growth spurt. However, recent fossil discoveries, improvements in research methods, and new insights into modern human ontogeny suggest that this may not have been the case. In this study, we examine alternative life history trajectories in H. erectus to re-evaluate adult stature estimates for KNM-WT 15000. We constructed a series of hypothetical growth curves by modifying known human and chimpanzee curves, calculating intermediate growth velocities, and shifting the age of onset and completion of growth in stature. We recalculated adult stature for KNM-WT 15000 by increasing stature at death by the percentage of growth remaining in each curve. The curve that most closely matches the life history events experienced by KNM-WT 15000 prior to death indicates that growth in this specimen would have been completed by 12.3 years of age. These results suggest that KNM-WT 15000 would have experienced a growth spurt that had a lower peak velocity and shorter duration than the adolescent growth spurt in modern humans. As a result, it is likely that KNM-WT 15000 would have only attained an adult stature of 163 cm (∼ 5'4 ″), not 185 cm (∼ 6'1 ″) as previously reported. KNM-WT 15000's smaller stature has important implications for evolutionary scenarios involving early genus Homo.

Mothers' reports of postpartum pain associated with vaginal and cesarean deliveries: results of a national survey.

BACKGROUND: As cesarean rates increase worldwide, a debate has arisen over the relationship of method of delivery to maternal postpartum physical health. This study examines mothers' reports of their postpartum experiences with pain stratified by method of delivery. METHODS: Listening to Mothers II was a survey of a total of 1,573 (200 telephone and 1,373 online) mothers aged 18 to 45 years, who had a singleton, hospital birth in 2005. They were interviewed by the survey research firm, Harris Interactive, in early 2006. Online respondents were drawn from an existing Harris panel. Telephone respondents were identified through a national telephone listing of new mothers. Results were weighted to reflect a United States national birthing population. Mothers were asked if they experienced any of eight postpartum conditions and the extent and the duration of the problem. Responses were compared by method of delivery. RESULTS: The most frequently cited postpartum difficulty was among mothers with a cesarean section, 79 percent of whom reported experiencing pain at the incision in the first 2 months after birth, with 33 percent describing it as a major problem and 18 percent reporting persistence of the pain into the sixth month postpartum. Mothers with planned cesareans without labor were as likely as those with cesareans with labor to report problems with postpartum pain. Almost half (48%) of mothers with vaginal births (68% among those with instrumental delivery, 63% with episiotomy, 43% spontaneous vaginal birth with no episiotomy) reported experiencing a painful perineum, with 2 percent reporting the pain persisting for at least 6 months. CONCLUSIONS: Substantial proportions of mothers reported problems with postpartum pain. Women experiencing a cesarean section or an assisted vaginal delivery were most likely to report that the pain persisted for an extended period.

Forearm articular proportions and the antebrachial index in Homo sapiens, Australopithecus afarensis and the great apes.

When hominin bipedality evolved, the forearms were free to adopt nonlocomotor tasks which may have resulted in changes to the articular surfaces of the ulna and the relative lengths of the forearm bones. Similarly, sex differences in forearm proportions may be more likely to emerge in bipeds than in the great apes given the locomotor constraints in Gorilla, Pan and Pongo. To test these assumptions, ulnar articular proportions and the antebrachial index (radius length/ulna length) in Homo sapiens (n=51), Gorilla gorilla (n=88), Pan troglodytes (n=49), Pongo pygmaeus (n=36) and Australopithecus afarensis A.L. 288-1 and A.L. 438-1 are compared. Intercept-adjusted ratios are used to control for size and minimize the effects of allometry. Canonical scores axes show that the proximally broad and elongated trochlear notch with respect to size in H. sapiens and A. afarensis is largely distinct from G. gorilla, P. troglodytes and P. pygmaeus. A cluster analysis of scaled ulnar articular dimensions groups H. sapiens males with A.L. 438-1 ulna length estimates, while one A.L. 288-1 ulna length estimate groups with Pan and another clusters most closely with H. sapiens, G. gorilla and A.L. 438-1. The relatively low antebrachial index characterizing H. sapiens and non-outlier estimates of A.L. 288-1 and A.L. 438-1 differs from those of the great apes. Unique sex differences in H. sapiens suggest a link between bipedality and forearm functional morphology.

A clinical "near miss" highlights risk management issues surrounding ultrasound-guided and wire-localised breast resections.

BACKGROUND: The introduction of the National Health Service (NHS) Breast Screening Programme has led to a considerable increase in the detection of impalpable breast cancer. Patients with impalpable breast cancer typically undergo oncological resection facilitated either by the insertion of guide wires placed stereo-tactically or through ultra-sound guided skin markings to delineate the extent of a lesion. The need for radiological interventions on the day of surgery adds complexity and introduces the risk that a patient may accidentally transferred to the operating room directly without the image guidance procedure. CASE REPORT: A case is described of a patient who required a pre-operative ultrasound scan in order to localise an impalpable breast cancer but who was accidentally taken directly to the operating theatre (OR) and anaesthetised without pre-operative intervention. The radiologist was called to the OR and an on-table ultrasound was performed without further consequence. CONCLUSION: It is evident that breast cancer patients undergoing image-guided resection are exposed to an additional layer of clinical risks. These risks are not offset by the World Health Organisation surgical safety checklist in its present guise. Here, we review a number of simple and inexpensive changes to the system that may improve the safety of the breast cancer patient undergoing surgery.

Sternocleidomastoid myocutaneous esophagoplasty for benign cervical stricture.

Benign strictures of the cervical esophagus that are resistant to dilation present a formidable challenge to the surgeon. Numerous varied techniques have been developed to restore swallowing. Reports of the sternocleidomastoid myocutaneous pedicled flap for repair of benign cervical strictures are scarce. We are reporting a case of residual lye stricture that was treated with sternocleidomastoid myocutaneous esophagoplasty in order to promote awareness of this procedure. This one-stage operation took 1 hour to complete. The patient began eating on postoperative day 4 and has not had any further symptoms.

Within-group human variation in the Asian Pleistocene: the three Upper Cave crania.

Numerous studies on Pleistocene samples have shown that within-group cranial variation was greater than that seen today. The three anatomically modern Upper Cave crania (UC 101, UC 102, and UC 103) from Zhoukoudian, China provide one of the best samples available for addressing the issue of the antiquity of the modern pattern of within-group cranial variability because archaeological evidence indicates that they are spatially and temporally restricted. Research on the Upper Cave fossils usually only includes UC 101 and UC 103 because of postmortem damage to UC 102's cranial vault. However, the face of UC 102 is undamaged, allowing for most facial measurements to be performed accurately. In this study we use facial dimensions to compare all three Upper Cave specimens, and we evaluate whether the variation seen among them is larger than that observed in extant populations. Using a worldwide sample of modern populations to establish a baseline, the three Upper Cave crania were compared to each other. Since there is disagreement over the sex of UC 102, this specimen is treated alternately as a female and as a male. Results show that the Upper Cave specimens exhibit significantly more variation than do individuals within more recent human populations, especially if UC 102 is considered male. Furthermore, results indicate that the fossils never fall into the same modern human group, and that each specimen is significantly atypical of its nearest modern neighbor in multivariate space. We conclude that the three Upper Cave crania do not represent a family group but are representative of the larger contemporaneous heterogeneous Asian Pleistocene population. Our results support the contention that today's within-group homogeneity is a relatively recent phenomenon, and is likely the result of a Neolithic population expansion and its many effects.

The morphometric relationship of Upper Cave 101 and 103 to modern Homo sapiens.

Since the discovery of the Homo sapiens crania from the Upper Cave of Zhoukoudian in northern China (UC 101, UC 102, and UC 103), no clear consensus has arisen regarding their affinities with modern populations. We use linear craniofacial measurements to compare UC 101 and UC 103 to a worldwide sample of H. sapiens that includes Paleoamericans and Archaic Indians, and employ Mahalanobis distance analysis and associated unweighted, unrestricted canonical variate analysis for the comparisons. Analyses indicate that UC 101 has consistent affinities with Easter Island and European populations, whereas UC 103 has more tenuous similarities with Australo-Melanesian groups. Both fossils exhibit some similarities to certain Paleoamerican and Archaic Indian individuals, but rarely cluster together. Upper Cave 103 is more of an outlier to modern populations than is UC 101. The fossils are not representative of any group to which they have been compared, but may be part of the generalized population that was ancestral to Paleoamericans.