Predation-driven biotic resistance fails to restrict the spread of a sessile rocky shore invader

The invasive barnacle Balanus glandula has progressively spread along the South African west coast. We used multiple approaches to assess the role of predation by indigenous whelks in regulating this expansion. B. glandula abundance and distribution were monitored annually while field observations and laboratory experiments assessed the relative predation pressure on B. glandula and the native barnacle Notomegabalanus algicola. In the mid-shore, the whelks Trochia cingulata and Burnt1pena lagenaria fed on N. algicola most often despite the alien B. glandula covering a mean of 86% of the shore at this site. Lower on the shore, the same feeding pattern was evident, although N. algicola was spatially dominant. Feeding experiments revealed that small (mean ± SD shell length: 13.9 ± 0.3 mm) and large (19.6 ± 0.5 mm) T. cingulata consumed up to 70% more N. algicola than B. glandula, displaying a significant avoidance of the alien. While small (15.5 ± 0.5 mm) B. lagenaria displayed the same pattern, large individuals (27.7 ± 0.4 mm) consumed equal numbers of the 2 barnacles. The avoidance of B. glandula may be explained by this species possessing thicker shell and opercular plates than N. algicola, while a narrow margin of vulnerable soft tissue around the circumference of the opercular plates makes the native an attractive prey choice. This study demonstrates that predation-driven biotic resistance has not contained the expansion of B. glandula along the South African coast

The functional brain networks that underlie Early Stone Age tool manufacture

After 800,000 years of making simple Oldowan tools, early humans began manufacturing Acheulian handaxes around 1.75 million years ago. This advance is hypothesized to reflect an evolutionary change in hominin cognition and language abilities. We used a neuroarchaeology approach to investigate this hypothesis, recording brain activity using functional near-infrared spectroscopy as modern human participants learned to make Oldowan and Acheulian stone tools in either a verbal or nonverbal training context. Here we show that Acheulian tool production requires the integration of visual, auditory and sensorimotor information in the middle and superior temporal cortex, the guidance of visual working memory representations in the ventral precentral gyrus, and higher-order action planning via the supplementary motor area, activating a brain network that is also involved in modern piano playing. The right analogue to Broca’s area—which has linked tool manufacture and language in prior work1,2—was only engaged during verbal training. Acheulian toolmaking, therefore, may have more evolutionary ties to playing Mozart than quoting Shakespeare

Neurological Soft Signs and Their Relationship to Cognitive and Clinical Efficacy of Atypical Antipsychotics in Schizophrenia

Neurological soft signs (NSS) are nonspecific indicators of brain dysfunction that are found to be in excess and correlated with cognitive dysfunction and psychopathology in patients with schizophrenia. The aim of the study was to examine whether the severity of NSS determines the efficacy of atypical antipsychotics in schizophrenia. Forty-three patients with schiophrenia were assessed on psychopathology and cognitive domains of executive functioning, memory, attention, and psychomotor speed at baseline and 6 months after they had been switched from typical to atypical antipsychotics. NSS were examined at baseline. The high-NSS group showed more severe psychopathology and greater impaired cognitive function than the low-NSS group at baseline. Following treatment, there were improvements in cognitive functioning and psychopathology with the low-NSS group, which showed significant improvements on measures of verbal fluency, memory, and psychomotor speed and negative symptoms. The high-NSS group also showed improvements on most of these measures, but the improvement was less than that seen in the low-NSS group. The presence of high NSS in schizophrenia patients impedes the improvement in cognitive function with atypical antipsychotics treatment

Bedding, hearths, and site maintenance in the Middle Stone Age of Sibudu Cave, KwaZulu-Natal, South Africa

Micromorphological analysis of sediments from the Middle Stone Age site of Sibudu Cave, KwaZulu-Natal, South Africa, provides a high-resolution sequence and evidence of site formation processes of predominantly anthropogenic deposits. This methodology allows for a detailed interpretation of individual anthropogenic activities, including the construction of hearths and bedding and the maintenance of occupational surfaces through the sweep out of hearths and the repeated burning of bedding. This analysis also provides a context for evaluating other studies at the site relating to magnetic susceptibility, paleobotany, paleozoology, anthracology, and studies of ochre