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The dynamic ribosome–translocon complex, which resides at the endoplasmic reticulum (ER) membrane, produces a major fraction of the human proteome1,2. It governs the synthesis, translocation, membrane insertion, N-glycosylation, folding and disulfide-bond formation of nascent proteins. Although individual components of this machinery have been studied at high resolution in isolation3–7, insights into their interplay in the native membrane remain limited. Here we use cryo-electron tomography, extensive classification and molecular modelling to capture snapshots of mRNA translation and protein maturation at the ER membrane at molecular resolution. We identify a highly abundant classical pre-translocation intermediate with eukaryotic elongation factor 1a (eEF1a) in an extended conformation, suggesting that eEF1a may remain associated with the ribosome after GTP hydrolysis during proofreading. At the ER membrane, distinct polysomes bind to different ER translocons specialized in the synthesis of proteins with signal peptides or multipass transmembrane proteins with the translocon-associated protein complex (TRAP) present in both. The near-complete atomic model of the most abundant ER translocon variant comprising the protein-conducting channel SEC61, TRAP and the oligosaccharyltransferase complex A (OSTA) reveals specific interactions of TRAP with other translocon components. We observe stoichiometric and sub-stoichiometric cofactors associated with OSTA, which are likely to include protein isomerases. In sum, we visualize ER-bound polysomes with their coordinated downstream machinery.

PURPOSE: This mixed methods study explored older adults’ experience using a bespoke active computer gaming (ACG) system designed to deliver falls prevention exercise. METHODS: Usability, acceptability and safety were evaluated through observation of system use, questionnaires, in-system ratings, and semi-structured interviews. Quantitative and qualitative data were synthesised concurrently to provide a deeper understanding of older adults’ experience with the system. RESULTS: N = 7 older adults (aged 73–88 years, most with increased fear of falling, and over half with reduced physical functioning) completed up to six uses of the system. Observations and qualitative feedback suggested that older adults’ experience with the system was influenced by physical health changes associated with ageing. Overall feedback after using the system was positive. Social support, from either the clinician or a peer, was a key theme influencing experience. CONCLUSIONS: Findings suggested that autonomous use of the system may not be feasible given the requirement and preference for social support.

[...]what is occurring during a pandemic, such as that with the COVID-19 pandemic, is likely far from intentional, or if it is, it is certainly reactive versus proactive. [...]there is uncertainty and change to a greater extent than usual. Not surprisingly, Kim and Ployhart found that those firms who invested in selected staffing and internal training prerecession both outproduced and outperformed their competitors. [...]they recovered more quickly after the recession due to the generated slack resources that protected and aided the firms. [...]even those who were not actively engaged in or planning an organizational change were more resilient because they were hiring the right people and had ongoing employee development. [...]importantly, change management not only offers promise as an aid in and of itself;it can also serve as an aid in the important areas mentioned by Rudolph etal.

Within the cell cargo is transported via motor proteins walking along microtubules. The affinity of motor proteins for microtubules is controlled by various layers of regulation like tubulin isoforms, post- translational modifications and microtubule associated proteins. Recently, the conformation of the microtubule lattice has also emerged as a potential regulatory factor, but to what extent it acts as an additional layer of regulation has remained unclear. In this study, we used cryo-correlative light and electron microscopy to study microtubule lattices inside cells. We find that, while most microtubules have a compacted lattice (∼41 Å), a significant proportion of the microtubule cores have expanded lattice spacings and that these lattice spacings could be modulated by the microtubule stabilizing drug Taxol. Furthermore, kinesin-1 predominantly binds microtubules with a more expanded lattice spacing (∼41.6 Å). The different lattice spacings present in the cell can thus act as an additional factor that modulates the binding of motor proteins to specific microtubule subsets.

Summary The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that controls cell cycle transitions. Its regulation by the spindle assembly checkpoint (SAC) is coordinated with the attachment of sister chromatids to the mitotic spindle. APC/C SUMOylation on APC4 ensures timely anaphase onset and chromosome segregation. To understand the structural and functional consequences of APC/C SUMOylation, we reconstituted SUMOylated APC/C for electron cryo-microscopy and biochemical analyses. SUMOylation of the APC/C causes a substantial rearrangement of the WHB domain of APC/C’s cullin subunit (APC2WHB). Although APC/CCdc20 SUMOylation results in a modest impact on normal APC/CCdc20 activity, repositioning APC2WHB reduces the affinity of APC/CCdc20 for the mitotic checkpoint complex (MCC), the effector of the SAC. This attenuates MCC-mediated suppression of APC/CCdc20 activity, allowing for more efficient ubiquitination of APC/CCdc20 substrates in the presence of the MCC. Thus, SUMOylation stimulates the reactivation of APC/CCdc20 when the SAC is silenced, contributing to timely anaphase onset., Graphical abstract, Highlights • APC/C SUMOylation causes substantial rearrangement of the WHB domain of the APC2 subunit • The repositioned WHB domain prevents robust binding of the MCC to the APC/C • SUMOylation stimulates robust APC/C reactivation during anaphase onset, Yatskevich et al. show that SUMOylation of APC/C results in substantial structural rearrangements of the APC/C. These structural changes allow APC/C to be reactivated robustly upon anaphase entry and when spindle assembly checkpoint is silenced, ensuring that mitotic progression is not delayed.

1 Mitochondria-cytoskeleton interactions modulate cellular 2 physiology by regulating mitochondrial transport, position-3 ing, and immobilization. However, there is very little struc-4 tural information defining mitochondria-cytoskeleton inter-5 faces in any cell type. Here, we use cryo-focused ion beam 6 milling-enabled cryo-electron tomography to image mam-7 malian sperm, where mitochondria wrap around the ciliary 8 cytoskeleton. We find that mitochondria are tethered to their 9 neighbors through inter-mitochondrial linkers and are an-10 chored to the cytoskeleton through ordered arrays on the 11 outer mitochondrial membrane. We use subtomogram aver-12 aging to resolve in-cell structures of these arrays from three 13 mammalian species, revealing they are conserved across 14 species despite variations in mitochondrial dimensions and 15 cristae organization. We find that the arrays consist of 16 boat-shaped particles anchored on a network of membrane 17 pores whose arrangement and dimensions are consistent 18 with voltage dependent anion channels. Proteomics and in-19 cell cross-linking mass spectrometry suggest that the con-20 served arrays are composed of glycerol kinase-like proteins. 21 Ordered supramolecular assemblies may serve to stabilize 22 similar contact sites in other cell types where mitochondria 23 need to be immobilized in specific subcellular environments, 24 such as in muscles and neurons. 25 sperm | mitochondria-cytoskeleton contact | cryo-electron tomography | cryo-26 FIB milling | cross-linking mass spectrometry | subtomogram averaging 27

SummaryMotile cilia are molecular machines used by a myriad of eukaryotic cells to swim through fluid environments. However, available molecular structures represent only a handful of cell types, limiting our understanding of how cilia are modified to support motility in diverse media. Here, we use cryo-focused ion beam milling-enabled cryo-electron tomography to image sperm flagella from three mammalian species. We resolve in-cell structures of centrioles, axonemal doublets, central pair apparatus, and endpiece singlets, revealing novel protofilament-bridging microtubule inner proteins throughout the flagellum. We present native structures of the flagellar base, which is crucial for shaping the flagellar beat. We show that outer dense fibers are directly coupled to microtubule doublets in the principal piece but not in the midpiece. Thus, mammalian sperm flagella are ornamented across scales, from protofilament-bracing structures rein-forcing microtubules at the nano-scale to accessory structures that impose micron-scale asymmetries on the entire assembly. Our structures provide vital foundations for linking molecular structure to ciliary motility and evolution.

SARS-CoV-2 has caused a global outbreak of severe respiratory disease (COVID-19), leading to an unprecedented public health crisis. To date, there has been over thirty-three million diagnosed infections, and over one million deaths. No vaccine or targeted therapeutics are currently available. We previously identified a human monoclonal antibody, 47D11, capable of cross-neutralising SARS-CoV-2 and the related 2002/2003 SARS-CoV in vitro, and preventing SARS-CoV-2 induced pneumonia in a hamster model. Here we present the structural basis of its neutralization mechanism. We describe cryo-EM structures of trimeric SARS-CoV and SARS-CoV-2 spike ectodomains in complex with the 47D11 Fab. These data reveal that 47D11 binds specifically to the closed conformation of the receptor binding domain, distal to the ACE2 binding site. The CDRL3 stabilises the N343 glycan in an upright conformation, exposing a conserved and mutationally constrained hydrophobic pocket, into which the CDRH3 loop inserts two aromatic residues. Interestingly, 47D11 preferentially selects for the partially open conformation of the SARS-CoV-2 spike, suggesting that it could be used effectively in combination with other antibodies that target the exposed receptor-binding motif. Taken together, these results expose a cryptic site of vulnerability on the SARS-CoV-2 RBD and provide a structural roadmap for the development of 47D11 as a prophylactic or post-exposure therapy for COVID-19.

Significance Acinetobacter baumannii has become challenging to treat due to its multidrug resistance mediated by active drug efflux pumps. The prototype member of the proteobacterial antimicrobial compound efflux (PACE) family, AceI of A. baumannii, is implicated in the transport of widely used antiseptic chlorhexidine, while AceR is associated with regulating the expression of the aceI gene. Here we apply native mass spectrometry to show that AceI forms dimers at high pH, and that chlorhexidine binding facilitates the functional form of the protein. Also, we demonstrate how AceR affects the interaction between RNA polymerase and promoter DNA both in the presence and in the absence of chlorhexidine. Overall, these results provide insight into the assembly and regulation of the PACE family., Few antibiotics are effective against Acinetobacter baumannii, one of the most successful pathogens responsible for hospital-acquired infections. Resistance to chlorhexidine, an antiseptic widely used to combat A. baumannii, is effected through the proteobacterial antimicrobial compound efflux (PACE) family. The prototype membrane protein of this family, AceI (Acinetobacter chlorhexidine efflux protein I), is encoded for by the aceI gene and is under the transcriptional control of AceR (Acinetobacter chlorhexidine efflux protein regulator), a LysR-type transcriptional regulator (LTTR) protein. Here we use native mass spectrometry to probe the response of AceI and AceR to chlorhexidine assault. Specifically, we show that AceI forms dimers at high pH, and that binding to chlorhexidine facilitates the functional form of the protein. Changes in the oligomerization of AceR to enable interaction between RNA polymerase and promoter DNA were also observed following chlorhexidine assault. Taken together, these results provide insight into the assembly of PACE family transporters and their regulation via LTTR proteins on drug recognition and suggest potential routes for intervention.

Background Active computer gaming (ACG) is a method of facilitating physical activity in older people to improve health outcomes. Purpose The purpose of this study was to update and extend a systematic review of the evidence for ACG to determine its effects on physical and cognitive health in older adults. Data Sources MEDLINE, EMBASE, CENTRAL in the Cochrane Library, and PsycINFO databases were searched from the date of the previous review (2011) to May 2016. Study Selection Eligible articles were randomized controlled trials (RCTs) investigating the effect of ACG in adults aged 65 and older. Data Extraction Thirty-five studies were eligible for inclusion. Two review authors independently conducted data extraction, risk-of-bias assessment, and coding of behavior change techniques. Outcomes of interest were analyzed as continuous data and pooled as standardized mean differences (SMD) and 95% confidence intervals (CI). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to determine the quality of the evidence. Data Synthesis Behavior change techniques (N = 106) were coded in the included studies (mean = 3.02). Data were pooled for 5 main outcomes of interest. Significant moderate effects in favor of ACG were observed for balance (SMD = 0.52, 95% CI = 0.24 to 0.79; 17 studies; 743 participants), for functional exercise capacity when intervention delivery was >120 minutes per week (SMD = 0.53, 95% CI = 0.15 to 0.90; 5 studies; 116 participants), and for cognitive function (SMD = –0.48, 95% CI = –0.80 to 0.17; 8 studies; 459 participants). There was no significant effect observed for functional mobility or fear of falling. Limitations The quality of the evidence for all comparisons was graded low or very low. Conclusions At present there is very little confidence that ACG improves physical and cognitive outcomes in older adults.

Yeast MTs do not appear to undergo the lattice compaction seen in mammalian MTs upon GTP hydrolysis. Binding of the +TIP Bim1, both between and within αβ-tubulin dimers, causes compaction of yeast MTs and their rapid disassembly., Microtubules are polymers of αβ-tubulin heterodimers essential for all eukaryotes. Despite sequence conservation, there are significant structural differences between microtubules assembled in vitro from mammalian or budding yeast tubulin. Yeast MTs were not observed to undergo compaction at the interdimer interface as seen for mammalian microtubules upon GTP hydrolysis. Lack of compaction might reflect slower GTP hydrolysis or a different degree of allosteric coupling in the lattice. The microtubule plus end–tracking protein Bim1 binds yeast microtubules both between αβ-tubulin heterodimers, as seen for other organisms, and within tubulin dimers, but binds mammalian tubulin only at interdimer contacts. At the concentrations used in cryo-electron microscopy, Bim1 causes the compaction of yeast microtubules and induces their rapid disassembly. Our studies demonstrate structural differences between yeast and mammalian microtubules that likely underlie their differing polymerization dynamics. These differences may reflect adaptations to the demands of different cell size or range of physiological growth temperatures.

In their focal article, Cucina, Walmsley, Gast, Martin, and Curtin (2017) raise an important and timely issue, but go too far in arguing that practitioners should abandon survey key driver analysis (SKDA) altogether. There are many valuable benefits to using SKDA, and rather than discontinuing the practice entirely, we suggest that a better approach is to focus on ways to make it even more valuable to organizations. It is true that this area is in need of further research, but instead of asking whether we are driving down the right road, perhaps the right question is, “Are we there yet?”

Rebecca Walkowitz’s rich book addresses translation not primarily as a craft that grants access to other literatures but as a vital component of twenty-first-century world literature, understood no...

© 2018 Stuart C. Howes, Elisabeth A. Geyerb, Benjamin LaFrance, Rui Zhang, Elizabeth H. Kellogg, Stefan Westermann, Luke M. Rice and Eva Nogales. Published with license by Taylor & Francis. The cytoskeleton of eukaryotic cells relies on microtubules to perform many essential functions. We have previously shown that, in spite of the overall conservation in sequence and structure of tubulin subunits across species, there are differences between mammalian and budding yeast microtubules with likely functional consequences for the cell. Here we expand our structural and function comparison of yeast and porcine microtubules to show different distribution of protofilament number in microtubules assembled in vitro from these two species. The different geometry at lateral contacts between protofilaments is likely due to a more polar interface in yeast. We also find that yeast tubulin forms longer and less curved oligomers in solution, suggesting stronger tubulin:tubulin interactions along the protofilament. Finally, we observed species-specific plus-end tracking activity for EB proteins: yeast Bim1 tracked yeast but not mammalian MTs, and human EB1 tracked mammalian but not yeast MTs. These findings further demonstrate that subtle sequence differences in tubulin sequence can have significant structural and functional consequences in microtubule structure and behavior.

Understanding how microbes utilize their environment is aided by visualizing them in their natural context at high resolution. Correlative imaging enables efficient targeting and identification of labelled viral and bacterial components by light microscopy combined with high resolution imaging by electron microscopy. Advances in genetic and bioorthogonal labelling, improved workflows for targeting and image correlation, and large-scale data collection are increasing the applicability of correlative imaging methods. Furthermore, developments in mass spectroscopy and soft X-ray imaging are expanding the correlative imaging modalities available. Investigating the structure and organization of microbes within their host by combined imaging methods provides important insights into mechanisms of infection and disease which cannot be obtained by other techniques.

14 p.-6 fig., A number of microtubule (MT)-stabilizing agents (MSAs) have demonstrated or predicted potential as anticancer agents, but a detailed structural basis for their mechanism of action is still lacking. We have obtained high-resolution (3.9–4.2 Å) cryo-electron microscopy (cryo-EM) reconstructions of MTs stabilized by the taxane-site binders Taxol and zampanolide, and by peloruside, which targets a distinct, non-taxoid pocket on β-tubulin. We find that each molecule has unique distinct structural effects on the MT lattice structure.Peloruside acts primarily at lateral contacts and has an effect on the “seam” of heterologous interactions,enforcing a conformation more similar to that of homologous (i.e., non-seam) contacts by which it regularizes the MT lattice. In contrast, binding of either Taxol or zampanolide induces MT heterogeneity. In doubly bound MTs, peloruside overrides the heterogeneity induced by Taxol binding. Our structural analysis illustrates distinct mechanisms of these drugs for stabilizing the MT lattice and is of relevance to the possible use of combinations of MSAs to regulate MT activity and improve therapeutic potential., This work was funded by NIH grant GM51487 (K.H.D., E.N.) and grants BIO2013-42984-R from Ministerio de Economia y Competitividad and S2010/BMD-2457 BIPEDD2 from Comunidad Autónoma de Madrid (J.F.D.).

Proteins that associate with microtubules (MTs) are crucial to generate MT arrays and establish different cellular architectures. One example is PRC1 (protein regulator of cytokinesis 1), which cross-links antiparallel MTs and is essential for the completion of mitosis and cytokinesis. Here we describe a 4-Å-resolution cryo-EM structure of monomeric PRC1 bound to MTs. Residues in the spectrin domain of PRC1 contacting the MT are highly conserved and interact with the same pocket recognized by kinesin. We additionally found that PRC1 promotes MT assembly even in the presence of the MT stabilizer taxol. Interestingly, the angle of the spectrin domain on the MT surface corresponds to the previously observed cross-bridge angle between MTs cross-linked by full-length, dimeric PRC1. This finding, together with molecular dynamic simulations describing the intrinsic flexibility of PRC1, suggests that the MT-spectrin domain interface determines the geometry of the MT arrays cross-linked by PRC1.

© 2016 Elsevier Inc. The assembly of microtubule-based cellular structures depends on regulated tubulin polymerization and directional transport. Here, we purify and characterize tubulin heterodimers that have human β-tubulin isotype III (TUBB3), as well as heterodimers with one of two β-tubulin mutations (D417H or R262H). Both point mutations are proximal to the kinesin-binding site and have been linked to an ocular motility disorder in humans. Compared to wild-type, microtubules with these mutations have decreased catastrophe frequencies and increased average lifetimes of plus- and minus-end-stabilizing caps. Importantly, the D417H mutation does not alter microtubule lattice structure or Mal3 binding to growing filaments. Instead, this mutation reduces the affinity of tubulin for TOG domains and colchicine, suggesting that the distribution of tubulin heterodimer conformations is changed. Together, our findings reveal how residues on the surface of microtubules, distal from the GTP-hydrolysis site and inter-subunit contacts, can alter polymerization dynamics at the plus- and minus-ends of microtubules.

Chromosomes segregate by interaction of spindle microtubules with kinetochores. In budding yeast the Dam1 complex forms rings around microtubules and recapitulates the functionality of a kinetochore–microtubule attachment. Mapping of subunits within the complex and their organization within the ring has made it possible to generate a model of Dam1 ring assembly., All eukaryotic cells must segregate their chromosomes equally between two daughter cells at each division. This process needs to be robust, as errors in the form of loss or gain of genetic material have catastrophic effects on viability. Chromosomes are captured, aligned, and segregated to daughter cells via interaction with spindle microtubules mediated by the kinetochore. In Saccharomyces cerevisiae one microtubule attaches to each kinetochore, requiring extreme processivity from this single connection. The yeast Dam1 complex, an essential component of the outer kinetochore, forms rings around microtubules and in vitro recapitulates much of the functionality of a kinetochore–microtubule attachment. To understand the mechanism of the Dam1 complex at the kinetochore, we must know how it binds to microtubules, how it assembles into rings, and how assembly is regulated. We used electron microscopy to map several subunits within the structure of the Dam1 complex and identify the organization of Dam1 complexes within the ring. Of importance, new data strongly support a more passive role for the microtubule in Dam1 ring formation. Integrating this information with previously published data, we generated a structural model for the Dam1 complex assembly that advances our understanding of its function and will direct future experiments.

A key first step in any reintroduction programme is to identify the former native range of the species in question. Such information provides the geographical framework for the project, within which potential reintroduction sites can be assessed. This study provides a historical review of the former distribution and status of the burbot, Lota lota, a freshwater gadoid extirpated from England. The review examines records of burbot presence and abundance from a range of historical and anecdotal sources and provides a qualitative evaluation of the species’ decline in English rivers. Burbot were found to have inhabited 42 rivers in eastern England ranging from the River Skerne in County Durham to the River Blyth in Suffolk. The literature suggests the species persisted in greater numbers in a few isolated areas such as the Yorkshire Derwent and the Great Ouse. The review also indicates that rather than be confined to slow-flowing lowland rivers, burbot occupied a range of aquatic environments including small upland headwaters as well as some lake systems

We report a method for combining the detection of single molecules (digital) and an ensemble of molecules (analog) that is capable of detecting enzyme label from 10(-19) M to 10(-13) M, for use in high sensitivity enzyme-linked immunosorbent assays (ELISA). The approach works by capturing proteins on microscopic beads, labeling the proteins with enzymes using a conventional multistep immunosandwich approach, isolating the beads in an array of 50-femtoliter wells (Single Molecule Array, SiMoA), and detecting bead-associated enzymatic activity using fluorescence imaging. At low concentrations of proteins, when the ratio of enzyme labels to beads is less than ∼1.2, beads carry either zero or low numbers of enzymes, and protein concentration is quantified by counting the presence of "on" or "off" beads (digital regime). (1) At higher protein concentrations, each bead typically carries multiple enzyme labels, and the average number of enzyme labels present on each bead is quantified from a measure of the average fluorescence intensity (analog regime). Both the digital and analog concentration ranges are quantified by a common unit, namely, average number of enzyme labels per bead (AEB). By combining digital and analog detection of singulated beads, a linear dynamic range of over 6 orders of magnitude to enzyme label was achieved. Using this approach, an immunoassay for prostate specific antigen (PSA) was developed. The combined digital and analog PSA assay provided linear response over approximately four logs of concentration ([PSA] from 8 fg/mL to 100 pg/mL or 250 aM to 3.3 pM). This approach extends the dynamic range of ELISA from picomolar levels down to subfemtomolar levels in a single measurement.

The in vivo evaluation of soft biomaterial implant remodeling routinely requires the surgical removal of the implant for subsequent histological assessment of tissue ingrowth and scaffold remodeling. This approach is very resource intensive, often destructive, and imposes practical limitations on how effectively these materials can be evaluated. MRI has the potential to non-invasively monitor the remodeling of implanted collagen scaffolds in real time. This study investigated the development of a model system to characterize the cellular infiltration, void area fraction, and angiogenesis in collagen scaffold implants using T2 relaxation time and apparent diffusion coefficient (ADC) maps along with conventional histological techniques. Initial correlations found statistically significant relationships between the MRI and histological parameters for various regions of the implanted sponges: T2 versus cell density (r ≈ -0.83); T2 versus void area fraction (r ≈ +0.78); T2 versus blood vessel density (r ≈ +0.95); ADC versus cell density (r ≈ -0.77); and ADC versus void area fraction (r ≈ +0.84). This suggests that MRI is sensitive to specific remodeling parameters and has the potential to serve as a non-invasive tool to monitor the remodeling of implanted collagen scaffolds, and to ultimately assess the ability of these scaffolds to regenerate the functional properties of damaged tissues such as tendons, ligaments, skin or skeletal muscle.

Inhibition of the aspartyl protease BACE-1 has the potential to deliver a disease-modifying therapy for Alzheimer's disease. Herein, is described a series of potent inhibitors based on an hydroxyethylamine (HEA) transition state mimetic template. These inhibitors interact with the non prime side of the enzyme using a novel edge-to-face interaction with Arg-296.

The ability to detect single protein molecules in blood could accelerate the discovery and use of more sensitive diagnostic biomarkers. To detect low-abundance proteins in blood, we captured them on microscopic beads decorated with specific antibodies and then labeled the immunocomplexes (one or zero labeled target protein molecules per bead) with an enzymatic reporter capable of generating a fluorescent product. After isolating the beads in 50-fl reaction chambers designed to hold only a single bead, we used fluorescence imaging to detect single protein molecules. Our single-molecule enzyme-linked immunosorbent assay (digital ELISA) approach detected as few as approximately 10-20 enzyme-labeled complexes in 100 microl of sample (approximately 10(-19) M) and routinely allowed detection of clinically relevant proteins in serum at concentrations (

1. Species reintroductions are an increasingly fashionable tool among conservation practitioners for restoring locally and nationally extinct populations. For a reintroduction programme to be successful, an understanding of the causes of the decline of a species is required. This, however, proves challenging when baseline data on the distribution and abundance of the species are limited. 2. This paper uses evidence from historical literature to map the former distribution of the burbot (Lota lota) within UK rivers before its extinction in the early 1970s. A scoring system was developed to model anecdotal descriptions of burbot abundance from the collected literature. 3. The former distribution was divided into four geographical areas based loosely on catchment boundaries. The literature identifies 42 rivers in eastern England in which the burbot was likely to have existed. The status of the species in the Thames catchment is still unclear as information from written sources is contradicted by evidence from the archaeological record. 4. The findings indicate that the year of source data was a significant predictor of burbot abundance across the former population as a whole and for three of the four geographical areas (the Trent catchment, the Fenland rivers and the Yorkshire rivers). The timing of the burbot's decline showed differences between the geographical regions, with the Trent catchment exhibiting an earlier decline than the Fenland and Yorkshire areas.

Contrast sensitivity responses were determined in diabetc subjects with retinopathy, macular disease and cataract The test proved reliable in discriminating between different degrees of cataract and between diabetics with no retmooathy, mild background retinopathy and early maculopathy Background retinopathy was shown to produce a loss of contrast sensitivity particularly at the low and medium frequencies These thresholds Increased with macular involvement Mild cataract was correlated with loss at the low and medium spatial frequenoes whilst moderate cataract suppressed sensitivity to a// frequencies Results are compared to colour discrimination /n each patient Key words Contrast sensitivity, colour discrimmation, diabetics with retinopathy, cataract Diabetes mellitus is a common cause of blindness in almost all communities. Severe visual loss occurs as a result of vitreous haemorrhage or retinal traction. More frequently, however, mild to moderate loss of vision occurs in diabetics as a result of damage to the macular region (maculopathy) or from cataract. Many eyes with diabetic retinopathy including some with early maculopathy, have normal Snellen visual acuity. The early “background signs” of diabetic retinopathy include small haemorrhages or microaneurysms, which may not effect the patient’s acuity but when sufficiently well established, may inhibit normal visual function. consequently

The objective of this study was to establish the optimal blood concentrations of the potent P-glycoprotein (P-gp) inhibitor GF120918 (Elacridar) required to achieve maximal knockout of this efflux transporter in the blood–brain barrier (BBB) of mice, rats, and guinea pigs. Genetic mdr 1a/b(−/−) knockout mice and “chemical” P-gp knockout mice, rats, and guinea pigs, generated by 24 h continuous infusion of GF120918, were used to investigate the effects of P-gp modulation on the brain penetration of SB-487946. Genetic mdr 1a/b(−/−) knockout mice demonstrated a >70-fold increase in brain:blood ratio of SB-487946 compared to mdr 1a/b(+/+) wild-type mice. There was a similar increase in SB-487946 brain:blood ratio in GF120918-treated mice ( ca . >67-fold) and rats ( ca. 95-fold) but a significantly smaller increase ( ca. 10-fold) in guinea pigs treated with GF120918. An appreciable difference was found in the BBB functional effect of P-gp efflux in rodents. GF120918 blood EC90 in mice and rats were similar however, the EC90 in guinea pigs was ca. 10-fold higher, suggesting a species difference in the activity of P-gp at the BBB in some rodents. This study establishes the optimal blood concentrations of GF120918 in relation to SB-487946, to achieve chemically induced P-gp knockout in rodents.

The Environment Agency have proposed that daily flow volume discharged from small wastewater treatment works should be capable of being measured to an accuracy of ′8%, where the daily totalised flow volume Is estimated to be greater than 5m 3 . If is estimated that every water company in the UK has several hundred small wastewater treatment works that will be required to be equipped with the capability of measuring the released daily totalised flow volume for specified periods. This paper investigates the feasibility of modifying existing dosing syphons, which are present within many of these works, to operate as flow measuring devices. Laboratory testing of a full-scale syphon demonstrated that by the addition of two water level detectors and a data logger to monitor the filling part of the syphon cycle, it is possible to accurately calculate the daily totalised flow volume within the Environment Agency's proposed performance criteria.

A greater understanding of the erosion behaviour of sewer sediments is necessary in order to reliably estimate the amount and nature of the sewer sediments released from deposits in sewers and transported either to waste water treatment plants or discharged into the environment. Research has indicated that microbial activity in sediment can influence the physical release of sediment from in-pipe deposits. This paper reports on a series of erosion tests in which sewer sediments from different sewer networks are kept under different environmental conditions and their resistance to erosion is examined. The erosion tests are carried out under aerobic and anaerobic conditions and two temperatures, one representing ambient sewer temperatures and a lower temperature that significantly suppresses bacterial activity.

Two cases of violent, drug-intoxicated patients who presented considerable problems in management, and were resistant to standard sedative agents, are described. Effective and safe sedation, without the need for full anaesthesia and endotracheal intubation, was achieved using titrated doses of thiopentone. The merits of selecting this agent in these circumstances are discussed.

Cytoskeletal motors perform critical force generation and transport functions in eukaryotic cells. Engineered modifications of motor function provide direct tests of protein structure-function relationships and potential tools for controlling cellular processes or for harnessing molecular transport in artificial systems. Here, we report the design and characterization of a panel of cytoskeletal motors that reversibly change gears-speed up, slow down or switch directions-when exposed to blue light. Our genetically encoded structural designs incorporate a photoactive protein domain to enable light-dependent conformational changes in an engineered lever arm. Using in vitro motility assays, we demonstrate robust spatiotemporal control over motor function and characterize the kinetics of the optical gearshifting mechanism. We have used a modular approach to create optical gearshifting motors for both actin-based and microtubule-based transport. © 2014 Macmillan Publishers Limited. All rights reserved.