Fearful apes or nervous goats? Another look at functions of dispositions or traits.

In his article, Grossmann argues that, in the context of human cooperative caregiving, heightened fearfulness in children and human sensitivity to fear in others are adaptive traits. I offer and briefly defend a rival hypothesis: Heightened fearfulness among infants and young children is a maladaptive trait that did not get deselected in the process of evolution because human sensitivity to fear in others mitigates its disadvantageous effects to a sufficient extent.

Femoral Footprint Visualization Using a Transtibial Portal in Anterior Cruciate Ligament Reconstruction.

In traditional endoscopic anterior cruciate ligament (ACL) reconstruction, inadequate visualization of the femoral footprint through a lateral portal frequently causes surgical errors. Although various portal locations have been reported, no study has identified ideal locations for specific portals in relation to ACL reconstruction. This article presents the new transtibial portal technique (ie, the use of an existing tibial tunnel). This technique provides excellent direct visualization of the femoral ACL footprint without the need to create additional portals. It allows dynamic visualization of the relationship of the future graft with posterior cruciate ligament and bone structures. [Orthopedics. 2021;44(5):e691-e693.].

Students' responses to scenarios depicting ethical dilemmas: a study of pharmacy and medical students in New Zealand.

One of the key learning objectives in any health professional course is to develop ethical and judicious practice. Therefore, it is important to address how medical and pharmacy students respond to, and deal with, ethical dilemmas in their clinical environments. In this paper, we examined how students communicated their resolution of ethical dilemmas and the alignment between these communications and the four principles developed by Beauchamp and Childress. Three hundred and fifty-seven pharmacy and medical students (overall response rate=63%) completed a questionnaire containing four clinical case scenarios with an ethical dilemma. Data were analysed using multiple methods. The findings revealed that 73% of the qualitative responses could be exclusively coded to one of the 'four principles' determined by the Beauchamp and Childress' framework. Additionally, 14% of responses overlapped between the four principles (multiple codes) and 13% of responses could not be coded using the framework. The subsequent subgroup analysis revealed different response patterns depending on the case being reviewed. The findings showed that when students are faced with challenging ethical dilemmas their responses can be aligned with the Beauchamp and Childress framework, although more contentious dilemmas involving issues of law are less easily categorised. The differences between year and discipline groups show students are developing ethical frames of reference that may be linked with their teaching environments and their levels of understanding. Analysis of these response patterns provides insight into the way students will likely respond in 'real' settings and this information may help educators prepare students for these clinical ethical dilemmas.

Kinesin-8 motors improve nuclear centering by promoting microtubule catastrophe.

In fission yeast, microtubules push against the cell edge, thereby positioning the nucleus in the cell center. Kinesin-8 motors regulate microtubule catastrophe; however, their role in nuclear positioning is not known. Here we develop a physical model that describes how kinesin-8 motors affect nuclear centering by promoting a microtubule catastrophe. Our model predicts the improved centering of the nucleus in the presence of motors, which we confirmed experimentally in living cells. The model also predicts a characteristic time for the recentering of a displaced nucleus, which is supported by our experiments where we displaced the nucleus using optical tweezers.

Cell polarity: which way to grow in an electric field?

Cell polarity can be influenced by an electric field, but the mechanisms behind this response are poorly understood. A new paper shows that fission yeast cells change their direction of growth in an external electric field and suggests mechanisms based on the cortical pH gradient and on electrophoresis of membrane proteins.

Min-protein oscillations in Escherichia coli with spontaneous formation of two-stranded filaments in a three-dimensional stochastic reaction-diffusion model.

We introduce a three-dimensional stochastic reaction-diffusion model to describe MinD/MinE dynamical structures in Escherichia coli. This model spontaneously generates pole-to-pole oscillations of the membrane-associated MinD proteins, MinE ring, as well as filaments of the membrane-associated MinD proteins. Experimental data suggest MinD filaments are two-stranded. In order to model them we assume that each membrane-associated MinD protein can form up to three bonds with adjacent membrane-associated MinD molecules and that MinE induced hydrolysis strongly depends on the number of bonds MinD has established.