Genetic Control of Plant Development by Overriding a Geometric Division Rule

Formative cell divisions are critical for multicellular patterning. In the early plant embryo, such divisions follow from orienting the division plane. A major unanswered question is how division plane orientation is genetically controlled, and in particular whether this relates to cell geometry. We have generated a complete 4D map of early Arabidopsis embryogenesis and used computational analysis to demonstrate that several divisions follow a rule that uses the smallest wall area going through the center of the cell. In other cases, however, cell division clearly deviates from this rule, which invariably leads to asymmetric cell division. By analyzing mutant embryos and through targeted genetic perturbation, we show that response to the hormone auxin triggers a deviation from the ``shortest wall'' rule. Our work demonstrates that a simple default rule couples division orientation to cell geometry in the embryo and that genetic regulation can create patterns by overriding the default rule.

Return to Work after Traumatic Hand Injuries: Medical, Personal and Work-related Factors

PURPOSE This study aimed to examine the work-related impact of open hand injuries, specifically, the amount of lost work days subsequent to the injury and factors associated with work-related rehabilitation. PATIENTS AND METHODS We retrospectivley included consecutive patients with acute hand injuries who were operated between 2008 and 2009 in the Division of Hand Surgery (n=435) at the Department of Orthopaedic, Plastic and Hand Surgery. Information was obtained from the medical records and via a self-reported questionnaire sent out in 2011. Patients younger than 18 or older than 65 years, as well as the unemployed were excluded from the study. Descriptive group analysis was used to establish statistical relationships between time off work (TOW) and possible influencing variables. Multiple linear regression was applied to analyse the impact of injury, personal and/or work-related factors on TOW. RESULTS The sample included 290 patients with a mean age of 38.9 (SD 13.2) years of whom 98.6% returned to work after a median absence of 45.5 days. Univariate analysis demonstrated an association of length of absence from work with socio-demographic, clinical and work-related factors. Multiple regression analysis indicated that the location of injury, the number of injured regions, the need for secondary surgery, age, and the type of occupation were independently associated with TOW. CONCLUSION Most factors associated with TOW after traumatic hand injuries could not be influenced. Possible interventions should probably target improved injury prevention, optimal clinical treatment and rehabilitation starting early after injury. Whether improvements in communication and enhancement of cooperation between the treatment teams, the workplace and the insurance carrier may support a staged and earlier return to work remains to be investigated.

The spatial and linguistic division of the city of Malaga

The city of Malaga underwent considerable growth in the 19th and 20th centuries. The territorial expansion paired with a massive influx of immigrants occurred in three waves and as a consequence the city of Malaga remains divided into three different parts up to today. The differences between these three neighbourhoods of the city lie in the type of houses, different cultural and industrial activities, socioeconomic level, and very interestingly, also in speech. Thus, the aim of this study is an examination of the interrelation between speech (phonetic features) and urban space in Malaga. A combination of quantitative and qualitative analysis was used, based on two types of data: 1) production data stemming from recordings of 120 speakers; 2) perception data (salience, estimated frequency of use, attitude, spatial and social perception, imitation) which was collected from several surveys with 120 participants each. Results show that the speech production data divides the city of Malaga clearly into three different parts. This tripartition is confirmed by the analysis of the perception data. Moreover, the habitants of these three areas are perceived as different social types, to whom a range of social features is attributed. That is, certain linguistic features, the different neighbourhoods of the city and the social characteristics associated with them are undergoing a process of indexicalization and iconization. As a result, the linguistic features in question function as identity markers on the intraurban level.