Eliminating the mystery from the concept of emergence

While some branches of complexity theory are advancing rapidly, the same cannot be said for our understanding of emergence. Despite a complete knowledge of the rules underlying the interactions between the parts of many systems, we are often baffled by their sudden transitions from simple to complex. Here I propose a solution to this conceptual problem. Given that emergence is often the result of many interactions occurring simultaneously in time and space, an ability to intuitively grasp it would require the ability to consciously think in parallel. A simple exercise is used to demonstrate that we do not possess this ability. Our surprise at the behaviour of cellular automata models, and the natural cases of pattern formation they mimic, is then explained from this perspective. This work suggests that the cognitive limitations of the mind can be as significant a barrier to scientific progress as the limitations of our senses

PERBURUAN KASUARI (Casuarius spp.) SECARA TRADISIONAL OLEH MASYARAKAT SUKU NDUGA DI DISTRIK SAWAERMA KABUPATEN ASMAT (The traditional hunting of Kasuari (Casuarius sp.) by Nduga tribe in Sawaerma District, Asmat Regency)

ABSTRAKPenelitian ini bertujuan mengkaji kegiatan perburuan kasuari secara tradisonal oleh masyarakat suku Nduga di Distrik Sawaerma, Kabupaten Asmat. Metode penelitian yang digunakan adalah metode deskriptif dengan teknik studi kasus. Hasil penelitian menunjukkan bahwa perburuan kasuari oleh masyarakat suku Nduga di Distrik Sawaerma bertujuan untuk memenuhi kebutuhan protein hewani dan pendapatan ekonomi keluarga. Aktivitas berburu kasuari oleh masyarakat suku Nduga masih dilakukan secara tradisional dengan menggunakan alat-alat tradisional seperti parang, kapak dan busur, anak panah. Selain itu cara penangkapan kasuari dilakukan dengan jerat leher dan jerat kaki maupun bantuan anjing berburu. Kegiatan berburu kasuari dilakukan secara secara perorangan maupun kelompok sesuai dengan hak adat (dusun). Kegiatan berburu lebih banyak dilakukan pada pagi dan malam hari, terutama saat musim hujan. Jenis kasuari yang terdapat pada areal hutan di sekitar Distrik Sawaerma adalah Kasuari Gelambir Ganda (Casuarius-casuarius), Kasuari Gelambir Tunggal (Casuarius unppendiculatus), dan Kasuari Kerdil (Casuarius bennetti). Rata-rata jumlah hasil buruan kasuari yang mengunakan jerat kaki atau leher sebanyak 2-3 ekor/hari, sedangkan menggunakan anjing berburu 1-2 ekor/hari. ABSTRACTThe research was aimed to discribe how the Nduga tribe in Sawaerma district, Asmat Regency is hunting kasuari traditionally. Descriptive method with case study was employed in this research. The resultshave shown that the main purposes of hunting kasusari by Nduga tribe were to fulfill their own need of protein as well as family income. The Nduga tribe have hunted kasuari traditionally by using traditional tools including cleavers, axe, and arrow. In addition, this tribe also hunts kasuari using neck and feet trapsas well as hunting dogs.The result also showed that Nduga tribe hunted kasuari alone or in group, and they did it based on their land customary. The most hunting time were in the morning and evening especially during rainy seasons. Single wattle (Casuarius unppendiculatus),double wattle (Casuarius-casuarius),and dwarf (Casuarius bennetti) cassowaries were foundin the area. Average number of kasuari hunted using neck and feet trap was 2 – 3 individu per day, while using hunting dogs was 1 – 2 individu per day.ABSTRAKPenelitian ini bertujuan mengkaji kegiatan perburuan kasuari secara tradisonal oleh masyarakat suku Nduga di Distrik Sawaerma, Kabupaten Asmat. Metode penelitian yang digunakan adalah metode deskriptif dengan teknik studi kasus. Hasil penelitian menunjukkan bahwa perburuan kasuari oleh masyarakat suku Nduga di Distrik Sawaerma bertujuan untuk memenuhi kebutuhan protein hewani dan pendapatan ekonomi keluarga. Aktivitas berburu kasuari oleh masyarakat suku Nduga masih dilakukan secara tradisional dengan menggunakan alat-alat tradisional seperti parang, kapak dan busur, anak panah. Selain itu cara penangkapan kasuari dilakukan dengan jerat leher dan jerat kaki maupun bantuan anjing berburu. Kegiatan berburu kasuari dilakukan secara secara perorangan maupun kelompok sesuai dengan hak adat (dusun). Kegiatan berburu lebih banyak dilakukan pada pagi dan malam hari, terutama saat musim hujan. Jenis kasuari yang terdapat pada areal hutan di sekitar Distrik Sawaerma adalah Kasuari Gelambir Ganda (Casuarius-casuarius), Kasuari Gelambir Tunggal (Casuarius unppendiculatus), dan Kasuari Kerdil (Casuarius bennetti). Rata-rata jumlah hasil buruan kasuari yang mengunakan jerat kaki atau leher sebanyak 2-3 ekor/hari, sedangkan menggunakan anjing berburu 1-2 ekor/hari. ABSTRACTThe research was aimed to discribe how the Nduga tribe in Sawaerma district, Asmat Regency is hunting kasuari traditionally. Descriptive method with case study was employed in this research. The resultshave shown that the main purposes of hunting kasusari by Nduga tribe were to fulfill their own need of protein as well as family income. The Nduga tribe have hunted kasuari traditionally by using traditional tools including cleavers, axe, and arrow. In addition, this tribe also hunts kasuari using neck and feet trapsas well as hunting dogs.The result also showed that Nduga tribe hunted kasuari alone or in group, and they did it based on their land customary. The most hunting time were in the morning and evening especially during rainy seasons. Single wattle (Casuarius unppendiculatus),double wattle (Casuarius-casuarius),and dwarf (Casuarius bennetti) cassowaries were foundin the area. Average number of kasuari hunted using neck and feet trap was 2 – 3 individu per day, while using hunting dogs was 1 – 2 individu per day

Network adaptation improves temporal representation of naturalistic stimuli in drosophila eye: II Mechanisms

Retinal networks must adapt constantly to best present the ever changing visual world to the brain. Here we test the hypothesis that adaptation is a result of different mechanisms at several synaptic connections within the network. In a companion paper (Part I), we showed that adaptation in the photoreceptors (R1-R6) and large monopolar cells (LMC) of the Drosophila eye improves sensitivity to under-represented signals in seconds by enhancing both the amplitude and frequency distribution of LMCs' voltage responses to repeated naturalistic contrast series. In this paper, we show that such adaptation needs both the light-mediated conductance and feedback-mediated synaptic conductance. A faulty feedforward pathway in histamine receptor mutant flies speeds up the LMC output, mimicking extreme light adaptation. A faulty feedback pathway from L2 LMCs to photoreceptors slows down the LMC output, mimicking dark adaptation. These results underline the importance of network adaptation for efficient coding, and as a mechanism for selectively regulating the size and speed of signals in neurons. We suggest that concert action of many different mechanisms and neural connections are responsible for adaptation to visual stimuli. Further, our results demonstrate the need for detailed circuit reconstructions like that of the Drosophila lamina, to understand how networks process information

Finite Element Analysis of Osteosynthesis Screw Fixation in the Bone Stock: An Appropriate Method for Automatic Screw Modelling

The use of finite element analysis (FEA) has grown to a more and more important method in the field of biomedical engineering and biomechanics. Although increased computational performance allows new ways to generate more complex biomechanical models, in the area of orthopaedic surgery, solid modelling of screws and drill holes represent a limitation of their use for individual cases and an increase of computational costs. To cope with these requirements, different methods for numerical screw modelling have therefore been investigated to improve its application diversity. Exemplarily, fixation was performed for stabilization of a large segmental femoral bone defect by an osteosynthesis plate. Three different numerical modelling techniques for implant fixation were used in this study, i.e. without screw modelling, screws as solid elements as well as screws as structural elements. The latter one offers the possibility to implement automatically generated screws with variable geometry on arbitrary FE models. Structural screws were parametrically generated by a Python script for the automatic generation in the FE-software Abaqus/CAE on both a tetrahedral and a hexahedral meshed femur. Accuracy of the FE models was confirmed by experimental testing using a composite femur with a segmental defect and an identical osteosynthesis plate for primary stabilisation with titanium screws. Both deflection of the femoral head and the gap alteration were measured with an optical measuring system with an accuracy of approximately 3 µm. For both screw modelling techniques a sufficient correlation of approximately 95% between numerical and experimental analysis was found. Furthermore, using structural elements for screw modelling the computational time could be reduced by 85% using hexahedral elements instead of tetrahedral elements for femur meshing. The automatically generated screw modelling offers a realistic simulation of the osteosynthesis fixation with screws in the adjacent bone stock and can be used for further investigations

Writing in Britain and Ireland, c. 400 to c. 800

No abstract available

Down-regulation of endothelial TLR4 signalling after apo A-I gene transfer contributes to improved survival in an experimental model of lipopolysaccharide-induced inflammation

The protective effects of high-density lipoprotein (HDL) under lipopolysaccharide (LPS) conditions have been well documented. Here, we investigated whether an effect of HDL on Toll-like receptor 4 (TLR4) expression and signalling may contribute to its endothelial-protective effects and to improved survival in a mouse model of LPS-induced inflammation and lethality. HDL cholesterol increased 1.7-fold (p < 0.005) and lung endothelial TLR4 expression decreased 8.4-fold (p < 0.005) 2 weeks after apolipoprotein (apo) A-I gene transfer. Following LPS administration in apo A-I gene transfer mice, lung TLR4 and lung MyD88 mRNA expression, reflecting TLR4 signalling, were 3.0-fold (p < 0.05) and 2.1-fold (p < 0.05) lower, respectively, than in LPS control mice. Concomitantly, LPS-induced lung neutrophil infiltration, lung oedema and mortality were significantly attenuated following apo A–I transfer. In vitro, supplementation of HDL or apo A–I to human microvascular endothelial cells-1 24 h before LPS administration reduced TLR4 expression, as assessed by fluorescent-activated cell sorting, and decreased the LPS-induced MyD88 mRNA expression and NF-κB activity, independently of LPS binding. In conclusion, HDL reduces TLR4 expression and signalling in endothelial cells, which may contribute significantly to the protective effects of HDL in LPS-induced inflammation and lethality

Contrasting patterns of population structure and gene flow facilitate exploration of connectivity in two widely distributed temperate octocorals

This is the final version of the article. Available from Springer Nature via the DOI in this record.Connectivity is an important component of metapopulation dynamics in marine systems and can influence population persistence, migration rates and conservation decisions associated with Marine Protected Areas (MPAs). In this study, we compared the genetic diversity, gene flow and population structure of two octocoral species, Eunicella verrucosa and Alcyonium digitatum, in the northeast Atlantic (ranging from the northwest of Ireland and the southern North Sea, to southern Portugal), using two panels of thirteen and eight microsatellite loci, respectively. Our results identified regional genetic structure in E. verrucosa partitioned between populations from southern Portugal, northwest Ireland, and Britain/France; subsequent hierarchical analysis of population structure also indicated reduced gene flow between southwest Britain and northwest France. However, over a similar geographical area, A. digitatum showed little evidence of population structure, suggesting high gene flow and/or a large effective population size; indeed, the only significant genetic differentiation detected in A. digitatum occurred between North Sea samples and those from the English Channel/northeast Atlantic. In both species the vast majority of gene flow originated from sample sites within regions, with populations in southwest Britain being the predominant source of contemporary exogenous genetic variants for the populations studied. Unsurprisingly, historical patterns of gene flow appeared more complex, though again southwest Britain appeared an important source of genetic variation for both species. Our findings have major conservation implications, particularly for E. verrucosa, a protected species in UK waters and listed by the IUCN as ‘Vulnerable’, and for the designation and management of European MPAs.We thank Natural England (project No. RP0286, contract No. SAE 03-02-146), the NERC (grant No. NE/L002434/1) and the University of Exeter for funding this research. Additional funding for sample collection, travel and microsatellite development was provided by the EU Framework 7 ASSEMBLE programme, agreement no. 227799, and NERC grant No. NBAF-362

Biology of human hair: Know your hair to control it

Hair can be engineered at different levels—its structure and surface—through modification of its constituent molecules, in particular proteins, but also the hair follicle (HF) can be genetically altered, in particular with the advent of siRNA-based applications. General aspects of hair biology are reviewed, as well as the most recent contributions to understanding hair pigmentation and the regulation of hair development. Focus will also be placed on the techniques developed specifically for delivering compounds of varying chemical nature to the HF, indicating methods for genetic/biochemical modulation of HF components for the treatment of hair diseases. Finally, hair fiber structure and chemical characteristics will be discussed as targets for keratin surface functionalization

Getting Down to Specifics: Profiling Gene Expression and Protein-DNA Interactions in a Cell Type-Specific Manner.

The majority of multicellular organisms are comprised of an extraordinary range of cell types, with different properties and gene expression profiles. Understanding what makes each cell type unique, and how their individual characteristics are attributed, are key questions for both developmental and neurobiologists alike. The brain is an excellent example of the cellular diversity expressed in the majority of eukaryotes. The mouse brain comprises of approximately 75 million neurons varying in morphology, electrophysiology, and preferences for synaptic partners. A powerful process in beginning to pick apart the mechanisms that specify individual characteristics of the cell, as well as their fate, is to profile gene expression patterns, chromatin states, and transcriptional networks in a cell type-specific manner, i.e. only profiling the cells of interest in a particular tissue. Depending on the organism, the questions being investigated, and the material available, certain cell type-specific profiling methods are more suitable than others. This chapter reviews the approaches presently available for selecting and isolating specific cell types and evaluates their key features