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Abstract Neurons are known to encode information not just by how frequently they fire, but also at what times they fire. However, characterizations of temporal encoding in sensory cortices under conditions of health and injury are limited. Here we characterized and compared the stimulus‐evoked activity of 1210 online‐sorted units in layers II and IV of rat barrel cortex under healthy and diffuse traumatic brain injury (TBI) (caused by a weight‐drop model) conditions across three timepoints post‐injury: four days, two weeks, and eight weeks. Temporal activity patterns in the first 50 ms post‐stimulus recording showed four categories of responses: no response or 1, 2, or 3 temporally‐distinct response components, that is, periods of high unit activity separated by silence. The relative proportions of unit response categories were similar between layers II and IV in healthy conditions but not in early post‐TBI conditions. For units with multiple response components, inter‐component timings were reliable in healthy and late post‐TBI conditions but disrupted by injury. Response component times typically shifted earlier with increasing stimulus intensity and this was more pronounced in layer IV than layer II. Surprisingly, injury caused a reversal of this trend and in the late post‐TBI condition no stimulus intensity‐dependence differences were observed between layers II and IV. We speculate this indicates a potential compensatory mechanism in response to injury. These results demonstrate how temporal encoding features maladapt or functionally recover differently in sensory cortex after TBI. Such maladaptation or functional recovery is layer‐dependent, perhaps due to differences in thalamic input or local inhibitory neuronal makeup.

Although teaching for social justice is a widely recognized goal of many teacher education programs, there are few supports for new teachers who wish to continue this kind of practice. In this article, I discuss the ways that a group of four new teachers found flexible support for developing a vision of teaching for social justice through participation in a teacher professional development network. In a context of political upheaval and wide-sweeping reforms, the new teachers planned and executed an event that celebrated the capabilities and talents of all children. Although this event had roots in the traditions of the professional development network, the new teachers brought certain generational specific concerns to their vision of social justice teaching, particularly around questions of action and audience. Exploring the ways that new teachers are supported to teach for social justice has implications for teacher education programs, teacher retention efforts, and professional development. (Contains 1 table.)

The classical view of sensory information mainly flowing into barrel cortex at layer IV, moving up for complex feature processing and lateral interactions in layers II and III, then down to layers V and VI for output and corticothalamic feedback is becoming increasingly undermined by new evidence. We review the neurophysiology of sensing and processing whisker deflections, emphasizing the general processing and organisational principles present along the entire sensory pathway—from the site of physical deflection at the whiskers to the encoding of deflections in the barrel cortex. Many of these principles support the classical view. However, we also highlight the growing number of exceptions to these general principles, which complexify the system and which investigators should be mindful of when interpreting their results. We identify gaps in the literature for experimentalists and theorists to investigate, not just to better understand whisker sensation but also to better understand sensory and cortical processing.

After laying their eggs and refilling the egg chamber, sea turtles scatter sand extensively around the nest site. This is presumed to camouflage the nest, or optimize local conditions for egg development, but a consensus on its function is lacking. We quantified activity and mapped the movements of hawksbill (Eretmochelys imbricata) and leatherback (Dermochelys coriacea) turtles during sand-scattering. For leatherbacks, we also recorded activity at each sand-scattering position. For hawksbills, we recorded breathing rates during nesting as an indicator of metabolic investment and compared with published values for leatherbacks. Temporal and inferred metabolic investment in sand-scattering was substantial for both species. Neither species remained near the nest while sand-scattering, instead moving to several other positions to scatter sand, changing direction each time, progressively displacing themselves from the nest site. Movement patterns were highly diverse between individuals, but activity at each sand-scattering position changed little between completion of egg chamber refilling and return to the sea. Our findings are inconsistent with sand-scattering being to directly camouflage the nest, or primarily for modifying the nest-proximal environment. Instead, they are consistent with the construction of a series of dispersed decoy nests that may reduce the discovery of nests by predators.

Despite the apparent importance of these dynamics, there is relatively little social science theorization and cross-national research on such global environmental issues. There is especially a paucity of cross-national, quantitative research in sociology that focuses on the social antecedents to environmental outcomes (for exceptions, see Burns et al. 1994, 1995; Kick et al. 1996; Grimes and Roberts 1995). We find this condition surprising given the substantial initial work of environmental sociologists (Dunlap and Catton 1978, 1979; Buttel 1987) and the key role social scientists might in principle play in addressing such worldwide problems (Laska 1993). As a consequence, we propose and assess a perspective on the global and national social causes of one environmental dynamic, the greenhouse effect.

Building on prior work in world-system analysis and human ecology, we test a macro-level theory that social and demographic causes of deforestation will vary across zones of the modern world-system. Using multivariate regression analysis, we examine models of deforestation over the period 1990-2000. We test for main effects of world-system posmon, two different population variables (urbanization and proportion under working age), and economic development within zone, as well as for the contextual effects of these variables as they operate differently across world-system positions. Our findings indicate that generic models of deforestation need to be qualified, because the particular social factors most closely associated with deforestation tend to vary by position in the global hierarchy. Deforestation at the macro level is best explained by considering effects of socio-demographic processes contextually, in terms of world-system dynamics. We discuss the findings in a more general world-systems and behavioral ecological framework, and suggest the field will be well served with more precise theorizing and closer attention to scope conditions.

In this Viewpoint, we aim to raise questions about the positioning of teachers and teacher knowledge in professional development networks. We contend that diverse purposes across professional development configurations labeled "networks" have been glossed over in the literature, obscuring important questions about teacher learning and its role in educational change. For example, are teachers viewed as change agents or objects of the change agendas of others? Whose purposes guide the work of the network? Is teacher knowledge viewed as something to be shared or something to be remediated? What role can networks positioned outside schools, districts and state reform plans have in improving education? We argue that, without taking a critical look at how networks and network research position teachers and their knowledge, the promise of networks is misunderstood and ultimately diluted.

Background: The need to support new teachers in urban public schools is well established, given current shortages and research that highlights serious issues with teacher retention. Debate continues about approaches to support for new teachers, including questions about the importance of developing an inquiry stance toward teaching. As more teacher preparation and professional development programs adopt inquiry-based methods, the theory and practice of these approaches deserve close analysis. Examining the ways in which inquiry-based programs strengthen or constrain new teacher agency is an important step in understanding the relationship between teacher retention and the deprofessionalization of teaching. Focus of Study: This article describes two groups of new teachers who experienced the inquiry-based programs of support in which they participated as silencing and uncritical. The authors argue that even in the best-intentioned programs, inquiry can become a fixed method in which the new teachers' voice and agency are lost. In each study, the new teachers worked to reclaim voice and agency through dialectic inquiry, which the authors characterize as local, self-reflexive, and able to embrace the tensions that mark many teaching situations. Research Design: This article draws on two yearlong practitioner research studies conducted with new teachers who were participating in structures intended to support their development as critical, reflective practitioners. Recommendations: Given the nature of teaching as a profession, the authors argue that dialectic inquiry can help new teachers develop important attributes of agency and critique. The authors advocate for inquiry-based teacher development programs that remain flexible and reflective and are able to support new teachers in a profession that can be silencing.

The use of environmental DNA (eDNA) to monitor rare and elusive species has great potential for conservation biology. Traditional surveying methods can be time-consuming, labour-intensive, subject to error or can be invasive and potentially damaging to habitat. The Trinidad golden treefrog (Phytotriades auratus) is one such species that would benefit from such an approach. This species inhabits the giant bromeliad (Glomeropitcairnia erectiflora) on two peaks on the Caribbean island of Trinidad. Traditional survey methods for this species have required the destruction of the giant bromeliad, which is the only known habitat of this frog. Here we described the development of an eDNA PCR-based assay that uses water drawn from the water-filled phytotelmata of the giant bromeliad along with the use of a synthetic DNA positive control that can be easily amplified in the bacterium Escherichia coli. The assay can detect to a DNA concentration of 1.4ng. Sampling of 142 bromeliads using this method revealed 9% were positive for P. auratus DNA. These data suggest that eDNA methods also have great potential for revealing the presence of elusive species in arboreal habitats.