From corps to discipline, part one: Charles d'Almeida, Pierre Bertin and French experimental physics, 1840-1880.

Academic careers in French science during the mid-nineteenth century were made within the Université de France, an integrated state system of secondary and higher education controlled by a centralized Parisian educational administration. Among the most respected members of the corps universitaire were Charles d'Almeida and Pierre Bertin, two historically obscure physiciens whose significance derives from their substantial contributions to the social organization, teaching and communication of French experimental physics. This two-part comparative biography uses their entwined careers to make a case for the emergence of a discipline of French experimental physics from the corps during the tumultuous politico-cultural transition from the Second Empire to the Third Republic. Of fundamental importance are disciplinary regimes of teaching and inspection within the corps, the foundation of the Société française de physique and the Journal de physique, and the diversification of the traditional pedagogical role of the Ecole normale supérieure, which, from around 1860, began to offer a career pathway for aspiring scientific researchers. Having established in this paper the socio-institutional mechanisms for the stabilization of a distinct field, in part two I characterize the epistemological-methodological aspects of French experimental physics.

What's nu? A re-examination of Maxwell's 'ratio-of-units' argument, from the mechanical theory of the electromagnetic field to 'On the elementary relations between electrical measurements'.

This re-examination of the earliest version of Maxwell's most important argument for the electromagnetic theory of light-the equality between the speed of wave propagation in the electromagnetic ether and the ratio of electrostatic to electromagnetic measures of electrical quantity-establishes unforeseen connections between Maxwell's theoretical electrical metrology and his mechanical theory of the electromagnetic field. Electrical metrology was not neutral with respect to field-theoretic versus action-at-a-distance conceptions of electro-magnetic interaction. Mutual accommodation between these conceptions was reached by Maxwell on the British Association for the Advancement of Science (BAAS) Committee on Electrical Standards by exploiting the measurement of the medium parameters-electric inductive capacity and magnetic permeability-on an arbitrary scale. While he always worked within this constraint in developing the 'ratio-of-units' argument mathematically, I maintain that Maxwell came to conceive of the ratio 'as a velocity' by treating the medium parameters as physical quantities that could be measured absolutely, which was only possible via the correspondences between electrical and mechanical quantities established in the mechanical theory. I thereby correct two closely-related misconceptions of the ratio-of-units argument-the counterintuitive but widespread notion that the ratio is naturally a speed, and the supposition that Maxwell either inferred or proved this from its dimensional formula.

The making of measurement: Editors' introduction.

This special issue consists of selected papers arising from the interdisciplinary conference "The Making of Measurement" held at the University of Cambridge on 23-24 July 2015. In this introduction, we seek ways to further productive interactions among historical, philosophical, and sociological approaches to the study of measurement without attempting to lay out a prescriptive program for a field of "measurement studies." We ask where science studies has led us, and answer: from the function to the making of measurement. We discuss whether there is anything privileged or exemplary about physical measurement, and alight upon models and metrology, two particular focuses of enquiry that emerge from our selection of papers. Those papers with a historical dimension complement an already well-developed body of historiography applied to measurement and metrology.

A systematic review of remotely delivered interventions to support wellbeing amongst caregivers of adults with acquired brain injuries.

Background There is a need for improved access to evidence-based interventions supporting the wellbeing of caregivers of adults with acquired brain injury (ABI). Remotely delivered interventions could address this need. The present systematic review sought to collate studies evaluating remotely delivered interventions designed to improve the wellbeing of caregivers of adults with an ABI, to summarise findings and to comment on the quality of this research. Methods Systematic searches were conducted up until December 2023. Study characteristics, populations, interventions and outcomes were outlined, and papers were appraised on methodological quality. The review was pre-registered (PROSPERO: CRD42020189235). Results Eleven studies meeting inclusion criteria were identified. Methodological quality was generally low to adequate. Most studies evaluated an intervention for caregivers of people with stroke, with a variety of types of interventions trialled. The majority of studies reported non-significant findings on wellbeing outcomes when compared to control conditions. Conclusions There is limited evidence supporting a remotely delivered intervention to improve wellbeing outcomes for ABI caregivers. Specific recommendations are provided, including the development of a core set of outcomes and replication of findings over time, which can improve research into the development and evaluation of remote interventions for this population.

Extracellular matrix-mediated tissue remodeling following axial movement of teeth.

Tooth eruption is a multifactorial process involving movement of existing tissues and formation of new tissues coordinated by a complex set of genetic events. We have used the model of the unopposed rodent molar to study morphological and genetic mechanisms involved in axial movement of teeth. Following extraction of opposing upper molars, lower molars supererupted by 0.13 mm. Labeled tissue sections revealed significant amounts of new bone and cementum apposition at the root apex of the unopposed side following supereruption for 12 days. Newly apposited cementum and alveolar bone layers were approximately 3-fold thicker in the experimental vs the control group, whereas periodontal ligament width was maintained. Tartrate-resistant acid phosphatase staining indicated bone resorption at the mesial alveolar walls of unopposed molars and provided in tandem with new bone formation at the distal alveolar walls an explanation for the distal drift of molars in this model. Microarray analysis and semiquantitative RT-PCR demonstrated a significant increase in collagen I, integrin beta5, and SPARC gene expression as revealed by comparison between the unopposed molar group and the control group. Immunohistochemical verification revealed increased levels of integrin beta5 and SPARC labeling in the periodontal ligament of the unopposed molar. Together our findings suggest that posteruptive axial movement of teeth was accomplished by significant formation of new root cementum and alveolar bone at the root apex in tandem with upregulation of collagen I, integrin beta5, and SPARC gene expression.

The effect of CO2 laser irradiation on PDL cell attachment to resected root surfaces.

OBJECTIVES: The effect of CO2 laser irradiation on PDL attachment to resected root ends was evaluated. STUDY DESIGN: Forty dentin wafers were divided into 4 equal groups. Groups I and II were not subjected to laser irradiation. Groups III and IV were subjected to irradiation with CO2 laser (wave length 10.6 mm). PDL cells attachment to the resected root surface (lased/non lased) and cell attachment to the root end filling material (gutta percha and MTA) were evaluated utilizing immunoflouresence microscopy and SEM. RESULTS: PDL cell attachment was observed on dentin surfaces (control samples) and dentin away from the laser strikes (irradiated samples). PDL cell attachment was observed on MTA but was absent on gutta percha. CONCLUSION: Absence of PDL attachment to laser irradiated dentin could be attributed to morphological surface changes in dentin produced by laser irradiation.

Inappropriate oral formulations and information in paediatric trials.

Previously, quality of formulations information provided for oral medications used in paediatric clinical trials published in 10 highly cited journals between 2002 and 2004 raised concerns. This short report explores if there was any subsequent improvement on how the formulations used in trials involving children <12 years reported in the same journals. Studies published between 2004 and 2008 were hand-searched and classified as containing adequate, some or no formulation information. Those involving solid dosage forms were further analysed. Only 31% (44/140) of publications provided adequate information, 5% less compared to 2002-2004 (28/76). There was a significant 12% rise (p<0.05) of no formulation information at all (37/140) and in tablets/capsules use (53/140), of which 3/4 gave no administration details, even for those under 6 years old, but a 12% decline in suitable paediatric formulations use (52/140 compared to 37/76). Contrary to expectations, overall quality of formulation information reported markedly deteriorated, jeopardising validity of clinical outcomes. The situation may reflect continued lack of awareness among investigators and other stakeholders of the importance of using suitable age-appropriate formulations.

Immunohistochemical localization of alphavbeta3 integrin receptor during experimental tooth movement.

During orthodontic treatment, multinucleated clast cells carry out the resorption of mineralized tissues. Adhesion of clast cells to the mineralized tissues is mediated by transmembrane cell-surface glycoproteins called integrins, specifically by the alphavbeta3 integrin, which plays an important role in the process of bone resorption. The role of the alphavbeta3 integrin in bone resorption leading to osteoporosis has been demonstrated, but its role in alveolar bone and root resorption during orthodontic tooth movement is unknown. This study examined the expression of the alphavbeta3 integrin during experimental tooth movement. Tooth movement was achieved in 16 male Sprague-Dawley rats (each weighing 120-200 g) with elastic bands between their maxillary first and second molars. The molar-bearing segments were dissected and processed for histologic and immunohistochemical examination. The expression of alphavbeta3 integrin was examined with 2 primary antibodies: a polyclonal anti-alphav integrin subunit antibody and a polyclonal anti-beta3 integrin subunit antibody. Negative controls were similarly processed but without incubation with primary antibodies. The alphavbeta3 integrin was expressed both by osteoclasts associated with alveolar bone resorption and by odontoclasts associated with root resorption during experimental tooth movement. Furthermore, the beta3 integrin subunit was expressed by the epithelial rests of Malassez in the periodontal ligament. Negative controls did not show immunolabeling. The alphavbeta3 integrin adhesion receptor is expressed during experimental tooth movement and might be involved in the process of mineralized tissue resorption and the functions of the epithelial rests of Malassez.

Proliferation of epithelial rests of Malassez during experimental tooth movement.

The epithelial rests of Malassez (ERM), remnants of Hertwig's epithelial root sheath, are found near the root surface in the periodontal ligament. The functional significance of the ERM is still unknown. The purpose of this study was to examine the behavior of the ERM during experimental tooth movement. Tooth movement was achieved in 12 male Sprague-Dawley rats (each, 120-200 g) by placing elastic bands between the maxillary right first and second molars. The left molars served as controls. The rats were killed after 6, 12, 18, 24, 60, and 72 hours. The mitotic activity of the ERM was assessed by injecting the animals with 5-bromo-2'-deoxyuridine (BrdU) 2 to 3 hours before killing by intracardial perfusion with 4% paraformaldehyde. The molar-bearing segments were dissected and processed for histological examination. The incorporated BrdU was detected by immunohistochemistry. The number of cells in each ERM cluster was counted in all groups. In the 18-, 24-, 60-, and 72-hour experimental groups, the cell numbers were significantly higher than in the controls. The surface areas of the ERM clusters were also measured in all groups, but only in the 18-, 24-, 60-, and 72-hour specimens were the areas significantly higher in the experimental than in the control groups. The ERM cells in the experimental specimens were labeled with anti-BrdU, while those in the controls were not. It was concluded that experimental tooth movement stimulates ERM cells to proliferate and increase in size. These increased activities of the ERM are consistent with a putative role for these cells in collagen turnover in the periodontal ligament that is accelerated during tooth movement.