bluuebunny/crossref_metadata_2025 huggingface dataset:
Crashworthiness of Glass/Polyester Composite Tubular Structures
Authors: Solaimurugan S. , Velmurugan R.
Published: October 2015

Advances in automotive and aircraft sectors lead to production of very high speed vehicles. The amount of energy that a vehicle absorbs during collision is a concern to ensure safer and more reliable vehicles. The FRP composite structural members dissipate huge amount of energy during collision and improves the vehicle crashworthiness. Thin walled FRP composite cylindrical shells are used as energy absorbers and absorb large amount of impact energy during collision. The energy absorbing capability of thin walled composite shells is quantified by specific energy absorption (SEA), the energy absorbed per unit mass of crushed material. The SEA of composite shells depends on the way in which the tube material is crushed (axially or laterally). Progressive deformation and stable collapse significantly reduce the forces experienced by the passengers in the event of sudden collision. This paper investigates the influence of fibre orientation and stacking sequence on the SEA of six-ply, 0Â°/90Â° Glass/Polyester composite cylindrical shells under axial and lateral compression. The crushing resistance and SEA vary with proportion of axial (0Â°) and hoop (90Â°) fibre content and stacking sequence in the tubes. The energy absorption capability under lateral crushing is compared with that of axial compression.
Making further inquiries: Policing in context in Brixton and Khayelitsha
Authors: Dixon Bill
Published: October 2015

Only rarely do inquiries into policing investigate the social context within which it takes place. This article looks at two inquiries that chose to take on this task: Lord Scarman’s into the Brixton disorders in London in April 1981; and Justice Kate O’Regan and Advocate Vusi Pikoli’s into the current state of policing in Khayelitsha in the Western Cape. It argues that they should be applauded for doing so, but draws attention to how difficult it can be to persuade governments to address the deep-rooted social and economic problems associated with crises in policing rather than focus on reforming the police institution, its policies, procedures and practices.
Mapping Khayelitsha: The complexities of everyday policing in a high crime area
Authors: Freeman Laura , McDonald Claire
Published: October 2015

In order for a single South African police station to operate optimally, or indeed at any level of functionality at all, it is required to form cooperative relations with a host of external institutions. This is in addition to ensuring that the internal structural capacity of a police station is maintained. The Commission of Inquiry into Allegations of Police Inefficiency and a Breakdown in Relations between SAPS and the Community in Khayelitsha identified shortcomings in both internal structures and the functioning of external relations. Here, we provide an overview of the stakeholders that make up the policing web in Khayelitsha. This forms the basis for clearer understandings of on-the-ground policing in this unsafe and violent neighbourhood.
Avoiding another Marikana massacre: Why police leadership matters
Authors: Newham Gareth
Published: October 2015

The Marikana Commission of Inquiry report presented damning findings against the South African Police Service (SAPS) National Commissioner, Riah Phiyega, and the senior commanders involved in the Marikana massacre. Their decision to disarm and disperse striking miners was found to be flawed and to have resulted in police officers unjustifiably shooting 112 striking mineworkers, killing 34 of them. Moreover, their integrity was found wanting on the basis that Phiyega and her senior commanders withheld crucial evidence, constructed misleading evidence, and provided untruthful testimony before the commission. This article argues that a necessary condition for improvements to take place in the SAPS relates to improving the top leadership of the organisation. Fortunately, the National Development Plan provides a starting point as to how this can be achieved.‘Police supervisors at any level need to be aware that their behaviour has a strong impact on the organisational culture, which in turn contributes to police behaviour.’
Leading a horse to water...: Assessing review mechanisms of SAPS performance
Authors: Burger Johan
Published: October 2015

There have been no shortage of reviews, evaluations and audits of police performance in South Africa over the past decade. This article provides a detailed description of the key findings of a number of reviews relating to the role and function of the SAPS. A closer reading of these reviews points to considerable agreement about the systemic weaknesses that confront the police organisation today. What is problematised in this article is the apparent inability and/or unwillingness of senior leadership to address the organisational defects through deliberative and concerted interventions. This lack of action has dire consequences for both the police organisation and the communities it is supposed to serve.
Advanced source apportionment of size-resolved trace elements at multiple sites in London during winter
Authors: Visser S. , Slowik J. G. , Furger M. , Zotter P. , Bukowiecki N. , Canonaco F. , Flechsig U. , Appel K. , Green D. C. , Tremper A. H. , Young D. E. , Williams P. I. , Allan J. D. , Coe H. , Williams L. R. , Mohr C. , Xu L. , Ng N. L. , Nemitz E. , Barlow J. F. , Halios C. H. , Fleming Z. L. , Baltensperger U. , Prévôt A. S. H.
Published: October 2015

Abstract. Trace element measurements in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 aerosol were performed with 2 h time resolution at kerbside, urban background and rural sites during the ClearfLo winter 2012 campaign in London. The environment-dependent variability of emissions was characterized using the Multilinear Engine implementation of the positive matrix factorization model, conducted on data sets comprising all three sites but segregated by size. Combining the sites enabled separation of sources with high temporal covariance but significant spatial variability. Separation of sizes improved source resolution by preventing sources occurring in only a single size fraction from having too small a contribution for the model to resolve. Anchor profiles were retrieved internally by analysing data subsets, and these profiles were used in the analyses of the complete data sets of all sites for enhanced source apportionment. A total of nine different factors were resolved (notable elements in brackets): in PM10–2.5, brake wear (Cu, Zr, Sb, Ba), other traffic-related (Fe), resuspended dust (Si, Ca), sea/road salt (Cl), aged sea salt (Na, Mg) and industrial (Cr, Ni); in PM2.5–1.0, brake wear, other traffic-related, resuspended dust, sea/road salt, aged sea salt and S-rich (S); and in PM1.0–0.3, traffic-related (Fe, Cu, Zr, Sb, Ba), resuspended dust, sea/road salt, aged sea salt, reacted Cl (Cl), S-rich and solid fuel (K, Pb). Human activities enhance the kerb-to-rural concentration gradients of coarse aged sea salt, typically considered to have a natural source, by 1.7–2.2. These site-dependent concentration differences reflect the effect of local resuspension processes in London. The anthropogenically influenced factors traffic (brake wear and other traffic-related processes), dust and sea/road salt provide further kerb-to-rural concentration enhancements by direct source emissions by a factor of 3.5–12.7. The traffic and dust factors are mainly emitted in PM10–2.5 and show strong diurnal variations with concentrations up to 4 times higher during rush hour than during night-time. Regionally influenced S-rich and solid fuel factors, occurring primarily in PM1.0–0.3, have negligible resuspension influences, and concentrations are similar throughout the day and across the regions.
APOLLO_NG – a probabilistic interpretation of the APOLLO legacy for AVHRR heritage channels
Authors: Klüser L. , Killius N. , Gesell G.
Published: October 2015

Abstract. The cloud processing scheme APOLLO (AVHRR Processing scheme Over cLouds, Land and Ocean) has been in use for cloud detection and cloud property retrieval since the late 1980s. The physics of the APOLLO scheme still build the backbone of a range of cloud detection algorithms for AVHRR (Advanced Very High Resolution Radiometer) heritage instruments. The APOLLO_NG (APOLLO_NextGeneration) cloud processing scheme is a probabilistic interpretation of the original APOLLO method. It builds upon the physical principles that have served well in the original APOLLO scheme. Nevertheless, a couple of additional variables have been introduced in APOLLO_NG. Cloud detection is no longer performed as a binary yes/no decision based on these physical principles. It is rather expressed as cloud probability for each satellite pixel. Consequently, the outcome of the algorithm can be tuned from being sure to reliably identify clear pixels to conditions of reliably identifying definitely cloudy pixels, depending on the purpose. The probabilistic approach allows retrieving not only the cloud properties (optical depth, effective radius, cloud top temperature and cloud water path) but also their uncertainties. APOLLO_NG is designed as a standalone cloud retrieval method robust enough for operational near-realtime use and for application to large amounts of historical satellite data. The radiative transfer solution is approximated by the same two-stream approach which also had been used for the original APOLLO. This allows the algorithm to be applied to a wide range of sensors without the necessity of sensor-specific tuning. Moreover it allows for online calculation of the radiative transfer (i.e., within the retrieval algorithm) giving rise to a detailed probabilistic treatment of cloud variables. This study presents the algorithm for cloud detection and cloud property retrieval together with the physical principles from the APOLLO legacy it is based on. Furthermore a couple of example results from NOAA-18 are presented.
The effect of uncertainty in earthquake fault parameters on the maximum wave height from a tsunami propagation model
Authors: Burbidge D. , Mueller C. , Power W.
Published: October 2015

Abstract. Over the last decade precomputed tsunami propagation model databases have been used extensively for both tsunami forecasting and hazard and risk assessment. However, the effect of uncertainty in the earthquake source parameters on the results of the simulated scenarios of tsunami propagation has not always been examined in great detail. Here we have undertaken a systematic study of the uncertainty in the maximum wave height of a tsunami (hmax) as a function of the uncertainty in the rupture parameters of the earthquake that generates it (specifically the strike, dip, rake, depth and magnitude). We have shown that even for the simple case of a tsunami propagating over flat bathymetry, the coefficient of variation (CoV) and skewness of the distribution of hmax was a complex function of the choice of rupture parameter, distance and azimuth. The relationships between these parameters and CoV became even more complex as the bathymetry used became more realistic. This has major potential implications for both how warning centres operate in the future and how the uncertainty in parameters describing the source should be incorporated into future probabilistic tsunami hazard assessments.
Increasing Financial Health through Casework Interventions
Authors: Smith Thomas E. , Richards Kristin V. , Shelton Victoria M.
Published: October 2015

Given a need to increase clients’ financial capability, social workers need a new set of techniques. Although financial education is a necessary service to increase financial capability, it is not enough. Practice models are needed to address the psychological and behavioral client needs that are exacerbated by inadequate financial management strategies. In this paper, six casework intervention models are discussed: motivational interviewing, harm reduction, marital and family therapy, dialectical behavior therapy, mindfulness training, and financial therapy. One model, the transtheoretical model, unites the six practice models. The need to validate casework interventions is essential through outcome research. Interventions not grounded in outcome research are speculative and may be misleading. A mixed model using quantitative and qualitative research techniques is proposed to build and evaluate casework intervention models.
Feedback Environment and Job Motivation among the Middle Leaders of Educational Organizations
Authors: Ling Ying-Leh , Kanesan Abdullah Abdul Ghani , Ismail Fairuz
Published: October 2015

This study aims to identify the level of feedback environment and job motivation among the school middle leaders. Basically, the objective of this study is to determine whether is there any significant difference between feedback environment and job motivation with gender group in the study. Moreover, this study also identifies whether is there any relationship between feedback environment and job motivation. Therefore, 63 subject coordinators of fifteen secondary schools in South Kinta district which is located in Perak Darul Ridzuan, Malaysia had participated in this study. Data for this study were collected through a questionnaire which was adapted from past researchers. Descriptive analysis was done using frequency and standard deviation while inferential analysis was carried out using Spearman correlation test and Mann-Whitney U test. Results have shown that the level of feedback environment and job motivation are high. In addition, the study also showed that feedback environment has a significant and positive relationship with job motivation. Accordingly, the results found that there is no significant difference for the feedback environment and job motivation with gender group. In terms of its implications, the school leaders in educational organizations should enhance the skills, knowledge and credibility in providing constructive feedback and consistency for shaping and enhancing self-efficacy among their followers. Generating useful feedback and help should be emphasized in the working environment by the principals in order to increase the motivation of the school middle leaders in achieving the targets set.
Does Inclusive Education Change Teachers’ Educational Goals? A Comparative Analysis of Two Cross-sectional Surveys in Austria
Authors: Schwab Susanne , Gebhardt Markus , Hessels Marco G.P. , Ellmeier Barbara , Gmeiner Sonia , Rossmann Peter
Published: October 2015

This study analyses whether an increasing inclusion rate in Austria was accompanied by a change in teachers’ educational goals and whether these goals were different for teachers in inclusive or non-inclusive settings. Educational goals were rated by 359 teachers in 1998 and 219 teachers in 2009. General pedagogical goals, as well as orientation on authority and discipline are considered less important by primary school teachers in inclusive classes than by those in schools without inclusion. The attitudes of teachers towards inclusion and teachers’ estimates of the impact of inclusion of students with different types of disabilities were not correlated in 1998, but positively correlated in 2009 with the emphasis on the individuality of the students in the class, and not correlated in 1998, but negatively correlated in 2009 with the orientation on authority and discipline. It is concluded that a positive change can be observed.
A Metafunctional Analysis of the News “ROK, DPRK Agree to Defuse Tension after Talks” on China Daily
Authors: Xu Bo
Published: October 2015

On the basis of the three metafunctions in Systemic Functional Linguistics (SFL): experiential, interpersonal and textual, the paper makes an analysis of the current news “ROK, DPRK Agree to Defuse Tension after Talks” on China Daily. The paper finds out that the political news has unique features in terms of experiential, interpersonal and textual function. Objectivity and accuracy of network news is realized via transitivity systems and third person pronoun in the news.
Description of a new sepioline species, Sepiola boletzkyi sp. nov. (Cephalopoda: Sepiolidae), from the Aegean Sea
Authors: Bello Giambattista , Salman Alp
Published: October 2015

A new sepioline species, Sepiola boletzkyi sp. nov. (Cephalopoda: Sepiolidae), is described based on two specimens from the Aegean Sea (eastern Mediterranean). The type specimens are lodged in the Ege University Faculty of Fisheries Museum of Izmir (Turkey). The new species belongs to the Sepiola atlantica group sensu Naef, hence it is compared with the species in this group, namely Sepiola affinis, Sepiola atlantica, Sepiola bursadhaesa, Sepiola intermedia, Sepiola robusta, Sepiola rondeletii, Sepiola steenstrupiana and Sepiola tridens. The male of S. boletzkyi sp. nov. differs from all the others in having the combination of homomorphous ventral arm tips, eight enlarged suckers, subdivided into two groups, in the dorsal row of the distal part of the hectocotylus and a dorsal lobe complementing the copulatory apparatus. In females of S. boletzkyi sp. nov. the bursa copulatrix is large and, unlike all other species in the genus, has a large fungiform process towards the mantle wall. The discovery of S. boletzkyi sp. nov. increases to 12 the number of NE Atlantic-Mediterranean species of Sepiola.
Egr-5 is a post-mitotic regulator of planarian epidermal differentiation
Authors: Tu Kimberly C , Cheng Li-Chun , TK Vu Hanh , Lange Jeffrey J , McKinney Sean A , Seidel Chris W , Sánchez Alvarado Alejandro
Published: October 2015

Neoblasts are an abundant, heterogeneous population of adult stem cells (ASCs) that facilitate the maintenance of planarian tissues and organs, providing a powerful system to study ASC self-renewal and differentiation dynamics. It is unknown how the collective output of neoblasts transit through differentiation pathways to produce specific cell types. The planarian epidermis is a simple tissue that undergoes rapid turnover. We found that as epidermal progeny differentiate, they progress through multiple spatiotemporal transition states with distinct gene expression profiles. We also identified a conserved early growth response family transcription factor, egr-5, that is essential for epidermal differentiation. Disruption of epidermal integrity by egr-5 RNAi triggers a global stress response that induces the proliferation of neoblasts and the concomitant expansion of not only epidermal, but also multiple progenitor cell populations. Our results further establish the planarian epidermis as a novel paradigm to uncover the molecular mechanisms regulating ASC specification in vivo.
Diurnal variation of winter F region ionosphere for solar minimum at both Zhongshan Station, Antarctica, and Svalbard Station, Arctic
Authors: Zhang Bei‐Chen , Yang Sheng‐Gao , Xu Sheng , Liu Rui‐Yuan , Häggström I. , Zhang Qing‐He , Hu Ze‐Jun , Huang De‐Hong , Hu Hong‐Qiao
Published: October 2015

Diurnal variation features of wintertime F2 peak electron density (NmF2) representative for solar minimum at both Zhongshan station, Antarctica, and Svalbard station are compared and analyzed. Both stations are located around cusp latitude and are almost on the same geomagnetic meridian plane in both hemispheres. For quiet time period, typical NmF2 diurnal variation features at Svalbard station show double peaks with a decrease of NmF2 around magnetic local noon (~UT + 3 h); NmF2 diurnal variation at Zhongshan station shows one major peak around magnetic local noon (~UT + 1.75 h), followed by a sharp decrease of NmF2, and a subpeak around 1500 UT. Simulation results of the high‐latitude ionospheres in both hemispheres agree well with observations at both stations. It is found that the major difference of NmF2 variation between both stations can be explained by the unique location of each station relative to the sunlit demarcation line during the day. For quiet time period, photoionization from lower latitude contributes to the major peak of NmF2 in the diurnal variation at Zhongshan station, while the interaction between horizontal convection and auroral precipitation is the main cause for NmF2 variation at Svalbard station. For active time period, both stations show the increase of NmF2 due to transportation of higher plasma density from lower latitudes on the dayside with the expansion of the polar cap and the additional ionization from soft‐precipitating electrons.
Observations of current sheets associated with solar wind reconnection exhausts passing through the near lunar wake
Authors: Xu Xiaojun , Wong Hon‐Cheng , Ma Yonghui , Wang Yi , Zuo Pingbing , Zhou Meng , Deng Xiaohua
Published: October 2015

Two reconnection exhausts were detected by one of the dual ARTEMIS orbiters in the solar wind near the Moon. Almost meanwhile, the other ARTEMIS orbiter encountered the two corresponding current sheets at the relatively marginal and central locations in the near lunar wake. Due to the Moon's direct absorption, the current density of the current sheet disappears within the wake. As a result, the wake magnetic field around the current sheets is changed. It is found that the variations of the magnetic field in the wake are primarily governed by two factors: diamagnetic current system at the wake boundary and the dropout of M direction currents (jM) within the wake. Instead of being almost unaltered as commonly assumed in the study of lunar wake, the magnetic field of the current sheets becomes potential with almost zero current density. With respect to the solar wind magnetic field, this potential magnetic field is weaker in the center and has an X line‐like configuration with significant normal components in the marginal portions of the wake. Our result may be applicable to nonconducting or weakly conducting contexts widely existing in the universe.
Reconstruction of the 236U input function for the Northeast Atlantic Ocean: Implications for 129I/236U and 236U/238U‐based tracer ages
Authors: Christl Marcus , Casacuberta Núria , Vockenhuber Christof , Elsässer Christoph , Bailly du Bois Pascal , Herrmann Jürgen , Synal Hans‐Arno
Published: October 2015

A reconstruction of historical discharges of 236U into the Northeast Atlantic Ocean by nuclear installations is presented. The nuclear reprocessing facilities Sellafield (SF), Great Britain (GB) and La Hague (LH), France and potentially also the nuclear fuel processing installation Springfields (SP), GB represent the main contributors of 236U in the Northeast Atlantic Ocean. Because data on 236U releases is lacking, 236U discharges from SP and SF are estimated based on the U‐isotopic systematics found in the discharges from LH. The resulting reconstruction of 236U releases indicates that, until 2013, a total of (95 ± 32) kg of 236U was discharged from SF, SP, and LH. In a second step, the reconstructed 236U releases are combined with 129I data from literature and oceanic and atmospheric box models are used to derive the 129I/236U and 236U/238U input functions that, for example, can be used to calculate tracer ages of Atlantic Waters in the Arctic Ocean. Our conceptual results show that the combination of 129I/236U and 236U/238U generally allows the estimation of tracer ages over the past approximately 25 years if contributions of 236U from global fallout are considered. Finally, as a proof of concept, the new method is applied to calculate tracer ages of Arctic Ocean surface samples (collected in 2011/2012) and the results are in good agreement with literature data. We conclude that the combination of 129I/236U with 236U/238U in a dual tracer approach provides a sensitive tool for the calculation of tracer ages and ventilation rates in the North Atlantic region.
The modulation of the seasonal cross‐shelf sea level variation by the cold pool in the Middle Atlantic Bight
Authors: Sha Jin , Jo Young‐Heon , Yan Xiao‐Hai , Liu W. T.
Published: October 2015

This study explores the influence of the cold pool in the Middle Atlantic Bight (MAB) to cross‐shelf sea surface slope by fitting an annual harmonic to temperature and salinity profiles from 1993 to 2012 and compares to the 20 year averaged altimetry sea level anomaly (SLA). The consistency within the bottom temperature, thermal steric height, total steric height, and altimetry observation validates that the cold pool induces a depressed sea level in the middle shelf overlapping with the dominant surface seasonal cycles. Temporally, the cold pool pattern is most apparent in July and August as a result of magnitude competition between the thermal and haline steric height. In addition, Ensemble Empirical Mode Decomposition (EEMD) is employed to reconstruct the altimetry SLA and reveals the middle‐shelf depression pattern from single year's SLA data. The locations of the SLA depression from 1993 to 2012 agree with the cold pool locations identified from in situ measurements, suggesting a promising application of altimetry SLA in the cold pool study. Conclusively, this study reveals the modulation of the cross‐shelf sea level variation by the cold pool, and contributes to the understanding of the sea level response to water masses on the continental shelf.
The impact of immobile zones on the transport and retention of nanoparticles in porous media
Authors: Molnar Ian L. , Gerhard Jason I. , Willson Clinton S. , O'Carroll Denis M.
Published: October 2015

Nanoparticle transport and retention within porous media is treated by conceptualizing the porous media as a series of independent collectors (e.g., Colloid Filtration Theory). This conceptualization assumes that flow phenomena near grain‐grain contacts, such as immobile zones (areas of low flow), exert a negligible influence on nanoparticle transport and assumes that retention and release of particles depends only on surface chemistry. This study investigated the impact of immobile zones on nanoparticle transport and retention by employing synchrotron X‐ray computed microtomography (SXCMT) to examine pore‐scale silver nanoparticle distributions during transport through three sand columns: uniform iron oxide, uniform quartz, and well‐graded quartz. Extended tailing was observed during the elution phase of all experiments suggesting that hydraulic retention in immobile zones, not detachment from grains, was the source of tailing. A numerical simulation of fluid flow through an SXCMT data set predicted the presence of immobile zones near grain‐grain contacts. SXCMT‐determined silver nanoparticle concentrations observed that significantly lower nanoparticle concentrations existed near grain‐grain contacts throughout the duration of all experiments. In addition, the SXCMT‐determined pore‐scale concentration gradients were found to be independent of surface chemistry and grain size distribution, suggesting that immobile zones limit the diffusive transport of nanoparticles toward the collectors. These results suggest that the well‐known overprediction of nanoparticle retention by traditional CFT may be due to ignoring the influences of grain‐grain contacts and immobile zones. As such, accurate prediction of nanoparticle transport requires consideration of immobile zones and their influence on both hydraulic and surface retention.
Evaluating an unconfined aquifer by analysis of age‐dating tracers in stream water
Authors: Solomon D. K. , Gilmore T. E. , Solder J. E. , Kimball B. , Genereux D. P.
Published: October 2015

The mean transit time (MTT) is a fundamental property of a groundwater flow system that is strongly related to the ratio of recharge rate to storage volume. However, obtaining samples for estimating the MTT using environmental tracers is problematic as flow‐weighted samples over the full spectrum of transit times are needed. Samples collected from the base flow of a gaining stream in the North Carolina Coastal Plain (West Bear Creek) that were corrected for exchange with the atmosphere yielded environmental tracer concentrations (SF6 and CFC‐11) very similar to flow‐weighted values from nine or ten streambed piezometers that directly sampled groundwater during low streamflow. At higher streamflow on the falling limb of the hydrograph, stream tracer concentrations (after correction for gas exchange) were significantly higher than the flow‐weighted mean from piezometers, consistent with dominance of the stream tracer signal by transient influx of surface water and/or younger subsurface water. The apparent MTT derived from SF6 in low flow stream water samples was 26 years, suggesting a groundwater recharge rate of about 210 mm/yr, that is consistent with vertical profiles obtained by sampling nested piezometers in the aquifer. When sampled under low flow conditions when streamflow consists of a high component of groundwater discharge, West Bear Creek appears to act as a flow‐weighted integrator of transit times and, streamflow samples can provide fundamental information regarding groundwater recharge rate and MTT. Our study suggests that watershed‐scale evaluation of some groundwater flow systems is possible without utilizing monitoring wells.
Dynein and Kinesin
Authors: Steele John W , Goldstein Lawrence SB
Published: October 2015

During the life cycle of a eukaryotic cell, chromosomes and other cellular materials must be distributed to daughter cells, proteins must be synthesised and delivered to their site of utilisation and cellular organelles must be delivered to, and retrieved from, appropriate places within the cell. In some cell types, such as neurons, essential cellular materials must be delivered across long distances from the cell body to distal axon terminals or dendrites. Because diffusion is incapable of accomplishing these tasks, eukaryotes have developed an active transport mechanism that relies on superfamilies of kinesin, dynein and myosin motor proteins that walk along microtubule or microfilament tracks. This article discusses how the microtubule‐based motors of the kinesin and dynein superfamilies mediate intracellular transport and cilia/flagella motility within eukaryotic cells.

Key Concepts

Microtubules have an intrinsic polarity that microtubule‐based motor proteins recognise to generate adenosine triphosphate (ATP)‐dependent unidirectional movement.

Both the kinesin and dynein catalytic polypeptides contain a stand‐alone motor domain, which is the actual microtubule‐dependent ATPase force‐generating unit of these motors.

Axonemal dyneins, which comprise the outer and inner dynein arms, power cilia and flagella beating by producing sliding movements between adjacent outer‐doublet microtubules.

Cytoplasmic dyneins are primarily transport motors driving retrograde transport through a minus‐end‐directed ATP‐dependent mechanism.

In neurons, dynein complexes with different intermediate chain isoforms have distinct roles, including cargo binding and transport, and phosphorylation of the intermediate chain may also specify binding to specific cargo.

Differences in the stalk and tail domains and various associated proteins (light chains) distinguish the multiple classes of kinesin superfamily members.

A key functional distinction between dyneins and kinesins is that, while kinesin family members can generate movement in the plus‐ or minus‐end direction, dynein motors generate only minus‐end‐directed movement.

To fill the numerous intracellular roles for plus‐end‐directed motility, eukaryotic cells have evolved a large array of kinesin superfamily members.

Microtubule‐based motors must be regulated on an individual and collective scale to facilitate the correct temporal and spatial intracellular placement of eukaryotic organelles.

Cytoplasmic dynein and its dynactin complex drive retrograde, minus‐end‐directed movement in neurons, whereas kinesins typically move towards the anterograde direction.
Epithelial Cells: Immunological Aspects
Authors: Pastore Saveria , Albanesi Cristina , Girolomoni Giampiero
Published: October 2015

Far from simply representing passive targets of environmental or immunological attack, epithelial cells play an active role in the generation and expression of protective immune responses. In response to physical, chemical or microbial perturbation of the epithelial barrier, these cells provide a valid defensive line by the expression of an array of soluble mediators with direct antimicrobial and/or chemotactic activities towards distinct immune cell populations and also towards cytokines and adhesion molecules that affect their functional activation. These epithelial cell‐driven molecular events are also involved in the pathogenesis of chronic inflammatory disorders, with the amplification of the inflammatory reactions because of a sustained crosstalk with infiltrating leucocytes. In particular, T‐cell‐derived cytokines have been identified as the most effective inducers of pro‐inflammatory signals in epithelial cells, in turn responsible for further recruitment and local activation of immune cells, leading to the eventual amplification of the inflammatory reaction.

Key Concepts

Epithelial cells organise the physical barriers of the body, the first defensive lines against environmental, physical, chemical and microbial insults.

In response to any damage to the physical barriers of the body, epithelial cells display their nature of resident components of the immune system and provide a second defensive line by the release of a plethora of active mediators.

In genetically predisposed individuals, a defective permeability of the skin early in life leads to the penetration of environmental allergens and to the initiation of the chronic inflammatory syndrome known as atopy.

Loss‐of‐function mutations in the filaggrin gene are the most significant and well‐replicated risk factor for the development of atopy.

To adequately defend against microbial colonisation and infection, epithelial cells are endowed with the complete armamentarium of innate immune defence.

The epidermal growth factor receptor and its endogenous ligands provide a formidable mechanism to enhance innate immunity, while they oppose activation of adaptive immunity in epithelial cells.

Patients with atopic dermatitis are more susceptible to cutaneous fungal, viral and bacterial pathogens because of an articulate defect in the innate immunity mechanisms of the epithelial cell.

Dysregulated expression of cytokines and chemokines in skin keratinocytes leads to sustained skin infiltration and local activation of a variety of immune cell populations in chronic skin inflammatory disorders including atopic dermatitis.

Epithelial cells possess a number of effective regulatory mechanisms to control intensity and duration of inflammatory events.
Lymphocytes: Gamma Delta
Authors: Chien Yueh‐hsiu , Chowdhury Roshni Roy
Published: October 2015

γδ T cells, together with αβ T cells and B cells, are the only cells that use somatic gene rearrangement to generate diverse receptors to recognise different antigens. All three types of cells are present together in all but the most primitive vertebrates, suggesting that each type of cell functions uniquely, and all are necessary to maintain host immune competence. Indeed, γδ T cells and αβ T cells differ in antigen recognition, the generation of antigen‐specific repertoire, activation requirement and effector function development. These aspects allow γδ T cells to occupy unique temporal and functional niches in host immune defence. In infections, γδ T cells respond earlier than αβ T cells; and also emerge late after pathogen numbers start to decline. Thus, these cells may be involved in both establishing and resolving the inflammatory response.

Key Concepts

γδ T cells are present together with αβ T cells and B cells in all but the most primitive vertebrates. These are the only cells using somatic gene rearrangement to generate diverse receptor for antigen recognition.

γδ T cells contribute uniquely to host immune competence and function differently from αβ T cells in host defence and immune surveillance.

γδ T cells are similar to B cells in antigen recognition, in that antigens of different size, shape and molecular nature are recognised directly, and γδ T cells and B cells can recognise the same antigens.

γδ T cells require thymic maturation process before coming out to the periphery, and this process does very little to determine what γδ T cells can recognise, but determine how they will function.

γδ T cells are the major initial responders in acute infections, especially in producing IL‐17 to initiate the inflammatory response.
Autoimmune Arthritis: Animal Models
Authors: McCann Fiona E , Wythe Sarah E
Published: October 2015

Animal models are used for the study of a number of human autoimmune diseases, including multiple sclerosis, diabetes, rheumatoid arthritis, systemic lupus erythematosis and spondyloarthropathies. Induced, spontaneous and genetically manipulated animal models can be described in terms of their parallels to human disease and as valuable tools for the development of potential therapies. Studies in animal models have led to a number of important discoveries, which have increased our understanding of the pathogenesis of autoimmune disease, including the roles played by regulatory T cells and T
H
17 cells. In addition, important therapeutic advances have emerged as a result of studies of immune intervention in animal models of autoimmunity. For example, tumour necrosis factor (TNF) blocking drugs, which are widely used for the treatment of rheumatic diseases, were developed following pre‐clinical testing in animal models.

Key Concepts

Animal models may be either spontaneously occurring or induced as a result of genetic manipulation, immunisation with a self‐antigen or triggered by pathogen‐associated molecular patterns (PAMPs) in genetically susceptible hosts.

No animal model completely mimics human disease.

Animal models can be used to delineate common mammalian immunological mechanisms, test novel therapeutic concepts and understand mechanisms of drug action, but therapeutic efficacy therein is not predictive of response in clinical trials.

The use of transgenic and knockout strains facilitates the identification of key genes that contribute to disease susceptibility and pathogenesis.
Immune Vasculitis
Authors: Gopaluni Seerapani , Jayne David
Published: October 2015

Vasculitides are a group of disorders characterised by inflammation and necrosis of the walls of blood vessels, resulting in narrowing or occlusion of the vessel lumen, leading to ischaemia and destruction of the tissues. They are usually classified according to the size of the vessels predominantly involved. The nomenclature of vasculitides was revised in 2012 at the second international Chapel Hill Consensus Conference (CHCC2012) to reflect the advances in our understanding of vasculitis. A wide range of immunopathological mechanisms have been implicated in the aetiology of vasculitis, and a subset of small‐vessel vasculitides are strongly associated with antineutrophil cytoplasmic antibodies (ANCA). The clinical presentation, often involving multiple organ systems, is heterogenous and depends on the size and site of the vessels involved. This makes both classification and diagnosis of these disorders challenging. Management of these conditions is fraught with the difficulty of balancing the benefits of immunosuppression with toxicity. However, with improved understanding of the immunopathogenesis, earlier diagnoses and newer targeted treatment options, improvements in morbidity and mortality have been reported.

Key Concepts

Vasculitis may be ‘idiopathic’ or ‘primary’ but it is important to rule out common mimics of vasculitis and the many underlying conditions that can induce a ‘secondary’ vasculitis.

Vasculitides are usually classified according to the predominant size of the vessels involved, but there is ongoing debate as to the most accurate and clinically useful way to classify the conditions.

Immunopathological mechanisms are diverse, with roles for both humoral and cellular immune mechanisms.

A subset of small‐vessel vasculitides are strongly associated with antineutrophil cytoplasmic antibody (ANCA), and this is often used as a biomarker to aid diagnosis.

There is strong evidence for a pathogenic role of ANCA in the ‘ANCA associated vasculitides’, but the extent of this continues to be debated.

Vasculitis is usually considered a ‘systemic’ disease with the propensity to affect blood vessels throughout the body, but individual clinical presentations may be limited to specific organ systems.

Many patients initially experience a prodrome of nonspecific symptoms such as malaise, fatigue, fever, night sweats or weight loss.

The prevalence of vasculitis is increasing. This may be due to the increased rates of diagnosis, due to clinical suspicion and use of biomarkers such as ANCA; increased survival postdiagnosis or a true increased incidence.

Further research into the underlying pathological processes is vital to identifying potential treatment targets.

Many trials are currently in progress and will contribute to the improving rates of morbidity and mortality in systemic vasculitis.
S
taudinger,
H
ermann
Authors: Furukawa Yasu
Published: October 2015

Hermann Staudinger (1881–1965) is a German organic chemist who made fundamental contributions to the foundation of macromolecular chemistry (or polymer chemistry), for which he was awarded the Nobel Prize in Chemistry in 1953. Trained as a classical organic chemist, Staudinger interpreted that polymers, such as rubber, cellulose, starches, plastics and proteins, are composed of almost arbitrarily big organic molecules or macromolecules. His theory provoked antipathy among his contemporaries, and the stormy macromolecular debate continued until his views were finally accepted in the chemical community in the 1930s. His extensive research on macromolecules provided the basis for the new discipline of macromolecular chemistry.
Developmental Systems Theory
Authors: Griffiths Paul E , Hochman Adam
Published: October 2015

Developmental systems theory (DST) is a wholeheartedly epigenetic approach to development, inheritance and evolution. The developmental system of an organism is the entire matrix of resources that are needed to reproduce the life cycle. The range of developmental resources that are properly described as being inherited, and which are subject to natural selection, is far wider than has traditionally been allowed. Evolution acts on this extended set of developmental resources. From a developmental systems perspective, development does not proceed according to a preformed plan; what is inherited is much more than DNA; and evolution is change not only in gene frequencies, but in entire developmental systems.

Key Concepts

Development has no single locus of control

Developmental outcomes are influenced by the contexts in which development unfolds

The developmental system of an organism is the matrix of resources that are required to reproduce the life cycle

The genome is designed to function in a specific developmental niche which is itself the product of evolution

The impact of any given cause is contingent upon the state of the system as a whole

The roles played by causal factors in development do not fall neatly into two kinds, one exclusively played by genes, the other played by nongenetic causes

Development is a dynamic process: the products of early stages of development can become the interactants of later stages

The notion of the ‘genetic program’ is of little heuristic value

The study of heredity will benefit from a broad approach that includes features of the developmental niche which are often overlooked

Evolution is change in developmental systems as a whole, and not only change in gene frequencies
Antibody Microarrays
Authors: Wingren Christer , Borrebaeck Carl
Published: October 2015

Antibody‐based microarray is a recently established proteomic technology, providing unique opportunities for multiplexed protein expression profiling of crude, non‐fractionated samples in a specific, sensitive and miniaturised manner. A microarray can be printed with a few up to several thousands of different antibodies carrying the desired specificities, the biological sample added (e.g. a serum sample) and any specifically bound analytes detected and quantified. The obtained microarray images are then transformed into protein expression profiles, or protein maps, revealing the composition of the sample at the molecular level. Bioinformatics is used to handle the often large‐scale data set(s) acquired. Protein expression profiling using this tool will provide new opportunities for biomarker discovery, drug target identification, (early) disease diagnostics and prognostics as well as insights into disease biology.

Key Concepts

Antibody microarrays are based on dispensing antibodies one‐by‐one in an ordered pattern, an array, onto a solid support.

Antibody‐based microarray is a miniaturised set‐up for simultaneously measuring numerous proteins in minute amount of sample.

Antibody microarrays can be used to perform multiplexed protein expression profiling of crude, complex samples.

Using antibody microarrays, less than a drop of blood is required in order to generate a protein map, or protein fingerprint, reflecting the protein content in the sample.

Multiplexed protein expression profiling using antibody microarrays provides novel opportunities for biomarker discovery, disease diagnosis and prognosis.
Epigenetic Regulation in Plants
Authors: Temel Aslihan , Janack Bianka , Humbeck Klaus
Published: October 2015

Environment‐sensitive plant development follows a program inscribed in the
DNA,
and differential expression of the genes is the prerequisite of this program. In the last decades, it was possible to unravel how genes are correctly transcribed in time and space by interaction of trans‐acting factors with cis elements often located in the promoter of a gene. However recently, we learned that, in addition, another level of control, called epigenetic regulation, acting via alterations in chromatin structure is involved.

In this review, we will first summarise the basic mechanisms underlying epigenetic control of gene expression in plants. In the following article, we will focus on some selected recent results showing epigenetic control of major steps in plant development. This review cannot cover all new results in the field and we want to apologise to all who are not mentioned.

Key Concepts

Plant development involves coordinated expression of genes.

Recent findings show that this is also under epigenetic control.

Epigenetic control is exerted by different mechanisms, including DNA methylation, histone modifications and chromatin remodelling.

These modifications alter chromatin state, and by this, it can induce or repress expression of genes.

Major developmental steps, including seed development, flowering, sexual reproduction and leaf senescence are controlled by epigenetic mechanisms.

Stress responses of plants are also regulated by epigenetic mechanisms.