bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular and expression analysis of a family of theAmblyomma americanumtick Lospins
Authors: Mulenga Albert , Khumthong Rabuesak , Blandon Maria A. 
Published: August 2007

SUMMARYSerine proteinase inhibitors (serpins) are a family of structurally similar but functionally diverse proteins that regulate several important proteolytic cascades in most branches of life. We have characterized 17 Amblyomma americanum serpin cDNAs here named as `Lospins' (L; an acronym for Lone Star tick serpin) that possess three β-sheets, eight α-helices and a reactive center loop consistent with the consensus serpin superfamily secondary structures. Visual inspection of deduced amino acid sequences revealed two patterns of basic residues: (i) 86DKSRVLKAYKRL97 in L5 and L13–16 and (ii) 158VRDKTRGKI166 in all Lospins, which are similar to consensus glycosaminoglycan (GAG) binding sites (XBnXmBX, where X and B are non-basic and basic residues, n=1 or 2 and m=1, 2 or 3). On three-dimensional models, the two putative GAG binding sites mapped onto α-helices D and F, respectively, with calculation of electrostatic surface potentials revealing basic patches on L5 and L13–16 models that are comparable to the heparin-binding site on antithrombin. RT-PCR expression analysis of 15 selected genes showed that the majority (11/15) of the Lospins were ubiquitously expressed in the midgut, ovary and salivary glands. On a neighbor-joining phylogeny guide tree, 15 serpins from other ticks and 17 Lospins from this study, a total of 32 tick serpin sequences, segregated into five groups with Lospins in groups A and D being conserved across tick species. The discovery of Lospins in this study sets the framework for future studies to understand the role of serpins in tick physiology.
How fast does a seal swim? Variations in swimming behaviour under differing foraging conditions
Authors: Gallon Susan L. , Sparling Carol E. , Georges Jean-Yves , Fedak Michael A. , Biuw Martin , Thompson Dave 
Published: August 2007

SUMMARYThe duration of breath-hold dives and the available time for foraging in submerged prey patches is ultimately constrained by oxygen balance. There is a close relationship between swim speed and oxygen utilisation, so it is likely that breath-holding divers optimise their speeds to and from the feeding patch to maximise time spent feeding at depth. Optimal foraging models suggest that transit swim speed should decrease to minimum cost of transport (MCT) speed in deeper and longer duration dives. Observations also suggest that descent and ascent swimming mode and speed may vary in response to changes in buoyancy. We measured the swimming behaviour during simulated foraging of seven captive female grey seals (two adults and five pups). Seals had to swim horizontally underwater from a breathing box to a submerged automatic feeder. The distance to the feeder and the rate of prey food delivery could be varied to simulate different feeding conditions.Diving durations and distances travelled in dives recorded during these experiments were similar to those recorded in the wild. Mean swim speed decreased significantly with increasing distance to the patch, indicating that seals adjusted their speed in response to travel distance, consistent with optimality model predictions. There was, however, no significant relationship between the transit swim speeds and prey density at the patch. Interestingly,all seals swam 10–20% faster on their way to the prey patch compared to the return to the breathing box, despite the fact that any effect of buoyancy on swimming speed should be the same in both directions. These results suggest that the swimming behaviour exhibited by foraging grey seals might be a combination of having to overcome the forces of buoyancy during vertical swimming and also of behavioural choices made by the seals.
Light-dependent magnetoreception: quantum catches and opponency mechanisms of possible photosensitive molecules
Authors: Johnsen Sönke , Mattern Erin , Ritz Thorsten 
Published: August 2007

SUMMARYDozens of experiments on magnetosensitive, migratory birds have shown that their magnetic orientation behavior depends on the spectrum of light under which they are tested. However, it is not certain whether this is due to a direct effect on the magnetoreceptive system and which photosensitive molecules may be involved. We examined 62 experiments of light-dependent magnetoreception in three crepuscular and nocturnal migrants (48 for the European robin Erithacus rubecula, ten for the silvereye Zosterops lateralis, and four on the garden warbler Sylvia borin). For each experiment, we calculated the relative quantum catches of seven of the eight known photosensitive molecules found in the eyes of passerine birds: a short- (SW), medium- (MW) and long-wavelength (LW) cone pigment, rhodopsin, melanopsin, and cryptochrome in its fully-oxidized and semiquinone state. The following five opponency processes were also calculated: LW–SW, LW–MW, MW–SW, LW–(MW+SW), and cryptochrome–semiquinone. While the results do not clearly show which receptor system may be responsible for magnetoreception, it suggests several candidates that may inhibit the process. The two significant inhibitors of magnetoreceptive behavior were overall irradiances (from 400 to 700 nm) higher than those found at sunset and high quantum catch by the LW receptor. The results were also consistent with the hypothesis that high quantum catch by the semiquinone form of cryptochrome inhibits magnetoreception. The opponency mechanism that best separated oriented from non-oriented behavior was LW–MW, where a difference above a certain level inhibited orientation. Certain regions of experimental spectral space have been over-sampled, while large regions have not been sampled at all, including: (1) from 440 to 500 nm at all irradiance levels, (2) for wavelengths longer than 570 nm from 1012 to 3×1012 photons s–1cm–2 and (3) for wavelengths less than 560 nm from 1012 to 3×1012 photons s–1cm–2 and below 5×1011 photons s–1 cm–2. Experiments under these conditions are needed to draw further conclusions.
Effects of elevated ecdysteroid on tissue expression of three guanylyl cyclases in the tropical land crabGecarcinus lateralis: possible roles of neuropeptide signaling in the molting gland
Authors: Lee Sung Gu , Bader Brandon D. , Chang Ernest S. , Mykles Donald L. 
Published: August 2007

SUMMARYTwo eyestalk (ES) neuropeptides, molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH), increase intracellular cGMP levels in target tissues. Both MIH and CHH inhibit ecdysteroid secretion by the molting gland or Y-organ (YO), but apparently through different guanylyl cyclase(GC)-dependent pathways. MIH signaling may be mediated by nitric oxide synthase (NOS) and NO-sensitive GC. CHH binds to a membrane receptor GC. As molting affects neuropeptide signaling, the effects of ecdysteroid on the expression of the land crab Gecarcinus lateralis β subunit of a NO-sensitive GC (Gl-GC-Iβ), a membrane receptor GC (Gl-GC-II) and a NO-insensitive soluble GC (Gl-GC-III) were determined. Gl-GC-Iβ isoforms differing in the absence or presence of an N-terminal 32-amino acid sequence and Gl-GC-III were expressed at higher mRNA levels in ES ganglia, gill,hepatopancreas, ovary and testis, and at lower levels in YO, heart and skeletal muscle. Three Gl-GC-II isoforms, which vary in the length of insertions (+18, +9 and +0 amino acids) within the N-terminal ligand-binding domain, differed in tissue distribution. Gl-GC-II(+18) was expressed highly in striated muscle (skeletal and cardiac muscles); Gl-GC-II(+9) was expressed in all tissues examined (ES ganglia, YO, gill, hepatopancreas, striated muscles and gonads); and Gl-GC-II(+0) was expressed in most tissues and was the dominant isoform in ES and thoracic ganglia. ES ablation, which increased hemolymph ecdysteroid, increased Gl-GC-II(+18) mRNA level in claw muscle. Using real-time RT-PCR, ES ablation increased Gl-GC-Iβ, Gl-GC-III and ecdysone receptor mRNA levels in the YOs ∼ten-, ∼four- and∼twofold, respectively, whereas Gl-GC-II mRNA level was unchanged. A single injection of 20-hydroxyecdysone into intact animals transiently lowered Gl-GC-Iβ in hepatopancreas, testis and skeletal muscle, and certain Gl-GC-II isoforms in some of the tissues. These data suggest that YO and other tissues can modulate responses to neuropeptides by altering GC expression.
The spatial, temporal and contrast properties of expansion and rotation flight optomotor responses inDrosophila
Authors: Duistermars Brian J. , Chow Dawnis M. , Condro Michael , Frye Mark A. 
Published: August 2007

SUMMARYFruit flies respond to panoramic retinal patterns of visual expansion with robust steering maneuvers directed away from the focus of expansion to avoid collisions and maintain an upwind flight posture. Panoramic rotation elicits comparatively weak syndirectional steering maneuvers, which also maintain visual stability. Full-field optic flow patterns like expansion and rotation are elicited by distinct flight maneuvers such as body translation during straight flight or body rotation during hovering, respectively. Recent analyses suggest that under some experimental conditions the rotation optomotor response reflects the linear sum of different expansion response components. Are expansion and rotation-mediated visual stabilization responses part of a single optomotor response subserved by a neural circuit that is differentially stimulated by the two flow fields, or rather do the two behavioral responses reflect two distinct control systems? Guided by the principle that the properties of neural circuits are revealed in the behaviors they mediate, we systematically varied the spatial, temporal and contrast properties of expansion and rotation stimuli, and quantified the time course and amplitude of optomotor responses during tethered flight. Our results support the conclusion that expansion and rotation optomotor responses are indeed two separate reflexes, which draw from the same system of elementary motion detectors, but are likely mediated by separate pre-motor circuits having different spatial integration properties, low-pass characteristics and contrast sensitivity.
Haze, clouds and limited sky visibility: polarotactic orientation of crickets under difficult stimulus conditions
Authors: Henze Miriam J. , Labhart Thomas 
Published: August 2007

SUMMARYField crickets (Gryllus campestris L.) are able to detect the orientation of the electric vector (e-vector) of linearly polarized light. They presumably use this sense to exploit the celestial polarization pattern for course control or navigation. Polarization vision in crickets can be tested by eliciting a spontaneous polarotactic response. Previously, wide and 100% polarized stimuli were employed to induce this behavior. However, field crickets live on meadows where the observation of the sky is strongly limited by surrounding vegetation. Moreover, degrees of polarization (d) in the natural sky are much lower than 100%. We have therefore investigated thresholds for the behavioral response to polarized light under conditions mimicking those experienced by the insects in the field. We show that crickets are able to rely on polarized stimuli of just 1° diameter. We also provide evidence that they exploit polarization down to an (average) polarization level of less than 7%, irrespective of whether the stimulus is homogeneous,such as under haze, or patched, such as a sky spotted by clouds. Our data demonstrate that crickets can rely on skylight polarization even under unfavorable celestial conditions, emphasizing the significance of polarized skylight orientation for insects.
An isolated insect leg's passive recovery from dorso-ventral perturbations
Authors: Dudek Daniel M. , Full Robert J. 
Published: August 2007

SUMMARYCockroaches recover rapidly from perturbations during high-speed running that allows them to cross unstructured terrains with no change in gait. Characterization of the exoskeletal material properties of the legs suggests that passive mechanical feedback could contribute to the self-stabilizing behavior. We imposed large, dorsal-ventrally directed impulsive perturbations to isolated hind legs having both a fixed and free body–coxa joint and measured their recovery. We tested a frequency-independent hysteretic damping model that effectively predicted the behavior of sinusoidal oscillations of isolated legs. Leg position reached its peak amplitude within 4–6 ms following an impulse. Position was 99% recovered within 16±3.3 ms for the stiffest possible leg configuration and within 46±6.6 ms for the most compliant leg configuration. The rapid recovery supports the hypothesis that passive musculo-skeletal properties play an important role in simplifying the control of high-speed locomotion.
Neural mechanisms underlying target detection in a dragonfly centrifugal neuron
Authors: Geurten Bart R. H. , Nordström Karin , Sprayberry Jordanna D. H. , Bolzon Douglas M. , O'Carroll David C. 
Published: August 2007

SUMMARY
Visual identification of targets is an important task for many animals searching for prey or conspecifics. Dragonflies utilize specialized optics in the dorsal acute zone, accompanied by higher-order visual neurons in the lobula complex, and descending neural pathways tuned to the motion of small targets. While recent studies describe the physiology of insect small target motion detector (STMD) neurons, little is known about the mechanisms that underlie their exquisite sensitivity to target motion. Lobula plate tangential cells (LPTCs), a group of neurons in dipteran flies selective for wide-field motion, have been shown to take input from local motion detectors consistent with the classic correlation model developed by Hassenstein and Reichardt in the 1950s. We have tested the hypothesis that similar mechanisms underlie the response of dragonfly STMDs. We show that an anatomically characterized centrifugal STMD neuron (CSTMD1) gives responses that depend strongly on target contrast, a clear prediction of the correlation model. Target stimuli are more complex in spatiotemporal terms than the sinusoidal grating patterns used to study LPTCs, so we used a correlation-based computer model to predict response tuning to velocity and width of moving targets. We show that increasing target width in the direction of travel causes a shift in response tuning to higher velocities, consistent with our model. Finally, we show how the morphology of CSTMD1 allows for impressive spatial interactions when more than one target is present in the visual field.
Visuospatial and Technical Ability in the Selection and Assessment of Higher Surgical Trainees in the London Deanery
Authors: Tansley P , Kakar S , Withey S , Butler P 
Published: August 2007

INTRODUCTION Despite awareness of the limitations of current selection and competency assessments, there is little consensus and alternatives have not been readily accepted. Essential surgical skills include visuospatial and technical ability. The aim of this study was to survey current methods of higher surgical trainee selection and assessment. We suggest ways to improve the process. MATERIALS AND METHODS Nine surgical training programmes in the London deanery were surveyed through questionnaires to programme directors, existing trainees and examination of deanery publications. RESULTS Testing of visuospatial and technical ability was piloted at selection only in a single general surgical department. Practical skills were assessed in 3/9 (33%) specialties (ENT, plastic and general surgery). Once selected, no specialty tested visuospatial and technical ability. Practical skills were tested in only 1/9 (11%) specialties (plastic surgery). The remaining 8/9 (89%) were ‘assessed’ by interview. CONCLUSIONS Lack of visuospatial and technical ability assessment was identified at selection and during higher surgical training. Airlines have long recognised early identification of these qualities as critical for efficient training. There is a need for more objective methods in this area prior to selection as time to assess surgical trainees during long apprenticeships is no longer available. We advocate a suitably validated competency-based model during and at completion of training.
Detecting Patient Allergy: Beware the LIE
Authors: Bismil Quamar , Bowles Christopher , Edwards Mark , Arastu Mateen , Ricketts David M , Solan Matthew C 
Published: August 2007

INTRODUCTION Allergy detection is important in surgical patients. Historically, the focus has been on drug allergies. There is increasing focus on non-drug allergy, specifically latex, iodine and elastoplast. PATIENTS AND METHODS The practice and knowledge of 24 pre-registration house officers was evaluated, with regard to patient allergy. For the second phase of the study, the cohort of 367 consecutive patients presenting to the orthopaedic pre-assessment clinic was prospectively assessed. RESULTS This prospective study demonstrates that standard history-taking misses a large number (38%) of such allergies. CONCLUSIONS With regard to allergy detection, we are living a LIE (by ignoring latex, iodine, elastoplast allergy). We suggest junior doctors should employ the mnemonic LIED (latex, iodine, elastoplast and drugs) when taking a medical history.
Relationship Between Occupation, Social Class and Time taken off Work Following a Whiplash Injury
Authors: Hagan KS , Naqui SZH , Lovell ME 
Published: August 2007

INTRODUCTION Little has been published about occupational and social factors in relation to time off work following a whiplash injury. PATIENTS AND METHODS We analysed 800 medicolegal case sheets from a consultant orthopaedic surgeon's practice. RESULTS Of those injured, 596 were working and 204 were unemployed or retired. The working group was further analysed. Severity of injury was estimated by analysing velocity of injury combined with vehicular damage. Mean time off work for a minor injury was 10.6 days, moderate 12.1 days, severe 13.8, and very severe 24.9 (P < 0.05). Looking at work categories as previously described in the literature, 20.5 days were taken off by heavy manual workers, light manual 15.7, driving 13.9, secretarial 9.2 and sedentary 12.8 (P < 0.05). Analysing as per social class showed that professionals required 7.0 days, intermediate 14.7 days, skilled non-manual 16.1 days, skilled manual 34.2 days, semi-skilled manual 33.2 days, and unskilled manual 11.5 days (P < 0.05). Nearly a third (31.2%) required no time off work, after 4 days off, 52.1% had returned to work and 90.1% were back at work after 30 days. Time off lasting more than 12 weeks occurred in 29 cases (4.9%). CONCLUSIONS Job style, severity of injury and social class have a bearing on time taken off work after road traffic accidents causing whiplash injury.
Transforming Growth Factor-β Gene Expression Studies in Nasal Mucosal Biopsies in Naturally Occurring Allergic Rhinitis
Authors: Salib Rami J 
Published: August 2007

Introduction Evidence has been provided of enhanced epithelial transforming growth factor-beta (TGF-β) immunoreactivity in allergic rhinitis, including correlation with intra-epithelial mast cell numbers, and the co-localisation of TGF-β receptors to mast cells, suggesting that the epithelial expression of TGF-β may represent an important biological process involved in either the recruitment or retention of mast cells within the epithelium in naturally occurring allergic rhinitis. Patients and Methods In order to extend the above findings, evaluation was undertaken in whole nasal biopsies from subjects with naturally occurring allergic rhinitis, of levels of TGF-β isotypes and receptors gene expression using real-time quantitative polymerase chain reaction (TaqMan RT-PCR), and the results compared to those for tumour necrosis factor-alpha (TNF-α), as a positive control. The study was also extended to evaluate gene expression for connective tissue growth factor (CTGF) and Smad proteins, as downstream markers of TGF-β bioactivity, in the same populations. Results There were no significant differences between the rhinitic and non-rhinitic groups in the expression of TGF-β isoforms or Smad-3, Smad-6 and Smad-7 proteins; however, there was increased gene expression for TGF-βRI and TGF-βRII along with CTGF in seasonal allergic rhinitis. TNF-α gene expression was also increased in seasonal allergic rhinitis, consistent with a more acute inflammatory response in this form of rhinitis. Conclusions This study advances our understanding of the role of TGF-β in the pathogenesis of the inflammatory response in allergic rhinitis.
Consent: Luck or Law?
Authors: Elmalik K , Wheeler RA 
Published: August 2007

INTRODUCTION The aim of this study was to identify whether clinicians are obtaining a valid consent for surgery, and ascertain the parents' perception of parental responsibility when giving consent for their children. PATIENTS AND METHODS Adults consenting for 100 children were questioned about the possession of parental responsibility, and their understanding of the concept. RESULTS Only 4 children had surgery without valid consent, these forms being signed by fathers without parental responsibility. However, only 5% of the sample stated that parental responsibility was required. More than 80% believed that cohabitation was a sufficient qualification to provide consent; fewer than 15% recognising any influence of marital status. It seems that, although 96% of consenters had parental responsibility, the validity of their consent was a product more of luck than of lawful behaviour. CONCLUSIONS The results demonstrate a wide gulf between the standards set by the Children Act 1989 and common practice, as perceived by parents. Furthermore, this reveals a significant disparity between the principles behind the statute, and the role that parents believe that they play in the 21st century.
The UK Government Two-Week Rule and its Impact on Melanoma Prognosis: An Evidence-Based Study
Authors: Pacifico MD , Pearl RA , Grover R 
Published: August 2007

INTRODUCTION In order to tackle increasing waiting lists the UK Government's ‘two-week rule’ was introduced for a number of cancers, including melanoma, in 2000. Whilst there is evidence that secondary prevention (i.e. early diagnosis) improves patient outcome, particularly in melanoma where early surgical excision is the only intervention to improve survival, there is as yet no evidence base for a 2-week limit. Any survival benefit from this Government target will not be demonstrable until long-term follow-up is available, realistically 10-year mortality figures in 2010. PATIENTS AND METHODS To investigate an evidence base for the two-week rule in melanoma, we performed a retrospective study on patients with suspected skin cancers referred to a rapid access Pigmented Lesion Clinic (PLC) over a 4-year period with long-term survival data, and compared them to a historical control group. RESULTS A total of 4399 patients attended the PLC from January 1993 to December 1996 and all were seen within 2 weeks. Ninety-six melanomas were diagnosed during this period with 96% treated within 2 weeks of GP referral, the majority (74%) excised on the day of PLC attendance. Melanoma patients (n = 78) diagnosed in the 2 years prior to the inception of the PLC waited 3–34 days for consultation and 4–74 days for treatment. Melanoma patients diagnosed in the PLC had significantly thinner tumours (Mann Whitney test, P < 0.001) and improved overall survival (χ2 18.1924; P < 0.001) compared with melanoma patients diagnosed before the inception of the clinic. CONCLUSIONS This is, to our knowledge, the first example that consultation within a 2-week time-frame of GP referral impacts patient survival and the first evidence base behind Government guidelines for this particular cancer.