bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Voltage Electron Microscopy
Authors: Cosslett V. E. 
Published: March 2009

SummaryThe main advantage of high voltage in electron microscopy is greater penetration. When using an aperture of optimum size the thickness of specimen that can be imaged increases almost linearly with applied voltage in the case of light elements, both when the criterion is image intensity and when it is resolution. For heavy elements the increase is less rapid. With a small aperture the increase in observable thickness is still less rapid, and ‘saturates’ towards I MV. For a specimen of given thickness, image definition increases nearly linearly with voltage owing to the decrease in chromatic aberration. Although ultimate resolving power improves with voltage, the gain is slight and is offset by a fall in contrast. The optimum voltage for very high resolution is probably between 200 and 300 kV. Radiation damage arising from ionization decreases with rising voltage, making easier the examination of sensitive materials such as polymers. On the other hand, ejection of atoms by head-on collision increases rapidly above a threshold voltage, causing observable defects in metals.In construction, a high-voltage microscope differs from the normal type only in size and in having an accelerator instead of a simple electron gun. In operation it differs little, apart from precautions to avoid fiashover in the accelerator. A decrease in response of viewing screens and photographic emulsions is more than compensated by higher brightness of the electron gun. The chief applications so far of the high-voltage microscope have been for studying thick films of metals, magnetic materials, ceramics and polymers. Improved preparation techniques should make it possible to study sections of biological tissues up to 5 μ thick. The observation of micro-organisms and other specimens in the wet state can be carried out in double-walled cells, but only at poor resolution. Still higher voltages, up to 3 or MV coupled with the use of an energy analyser or an image intensifier, should improve further the microscopy of such thick specimens.
Spectroscopic studies on two-iron ferredoxins
Authors: Sands R. H. , Dunham W. R. 
Published: March 2009

The application of magnetic resonance techniques to biological systems has permitted a detailed study of the nature of the active sites of many proteins that had not been possible previously. Among these is the whole class of iron—sulphur proteins which have been implicated as electron transport proteins in a variety of fundamental processes: photosynthesis, hydroxylation and nitrogen fixation to name but a few.The single-iron proteins in this class, the rubredoxins, have been studied extensively by chemical, spectroscopic and X-ray crystallographic techniques (Lovenberg, 1973), and the active site is composed of a single iron atom bound in a distorted tetrahedron of cysteine sulphur ligands. The iron is high-spin ferric in the oxidized state and high-spin ferrous in the reduced state. This structure is shown in Fig. I (α).
Zone-plate X-ray microscopy
Authors: Schmahl G. , Rudolph D. , Niemann B. , Christ O. 
Published: March 2009

The scope of this article is to describe a transmission X-ray microscope, possible biological applications of soft X-ray microscopy and preliminary results.For soft X-ray microscopy of biological specimens the wavelength range of 1–10 nm is best suited. Microscopy in this wavelength range requires intense X-ray sources as well as high-resolution X-ray lenses. Intense X-radiation is provided by the synchrotron radiation of electron and positron storage rings. Suited X-ray lenses are zone plates.A theoretical treatment of the contrast mechanism and the radiation damage as well as first experiments yield the following results. Firstly, relatively thick (1–10 μm) biological specimens can be investigated. This means that unsectioned dried and even wet cells and cell organelles in a natural state can be examined. Second, it will be possible to resolve cellular aggregates in live cells with a resolution in the region of ≤10nm.
Spin-labelled nucleic acids
Authors: Kamzolova S. G. , Postnikova G. B. 
Published: March 2009

The spin label method developed by McConnell 15 years ago is now widely used in studies of the structure and dynamic properties of a variety of the biological systems such as proteins and protein complexes, lipids and membranes, nucleic acids, nucleoproteins, etc.The ESR spectrum of the nitroxide radcal – the spin label – is very sensitive to its microenvironment and permits easy registration of even subtle alterations in it. If spin labels are attached to different sites of a macromolecule the information can be gained about conformational properties of all these local regions and, as a result, about the dynamic behaviour of the object as a whole.
Soft X-ray microscopes and their biological applications
Authors: Kirz Janos , Jacobsen Chris , Howells Malcolm 
Published: March 2009

In this review we propose to address the question: for the life-science researcher, what does X-ray microscopy have to offer that is not otherwise easily available?We will see that the answer depends on a combination of resolution, penetrating power, analytical sensitivity, compatibility with wet specimens, and the ease of image interpretation.
Rapid control prototyping for robot soccer
Authors: Jang Junwon , Han Soohee , Kim Hanjun , Ahn Choon Ki , Kwon Wook Hyun 
Published: March 2009

SUMMARYIn this paper, we propose rapid-control prototyping (RCP) for a robot soccer using the SIMTool that has been developed in Seoul National University, Korea, for the control-aided control system design (CACSD). The proposed RCP enables us to carry out the rapid design and the verification of controls for two-wheeled mobile robots (TWMRs), players in the robot soccer, without writing C codes directly and requiring a special H/W. On the basis of the proposed RCP, a blockset for the robot soccer is developed for easy design of a variety of mathematical and logical algorithms. All blocks in the blockset are made up of basic blocks offered by the SIMTool. Applied algorithms for specific purposes can be easily and efficiently constructed with just a combination of the blocks in the blockset. As one of the algorithms implemented with the developed blockset, a novel navigation algorithm, called a reactive navigation algorithm using the direction and the avoidance vectors based scheme (RNDAVS), is proposed. It is shown through simulations and experiments that the RNDAVS designed with the proposed RCP can avoid a local minima and the goal non-reachable with obstacles nearby (GNRON) arising from the existing methods. Furthermore, in order to validate the proposed RCP in a real game, we employ an official simulation game for the robot soccer, the SimuroSot. Block diagrams are constructed for strategy, path calculation, and the interface to the SIMTool. We show that the algorithms implemented with the proposed RCP work well in the simulation game.
A comparison of Arctic and Antarctic climate change, present and future
Authors: Walsh John E. 
Published: March 2009

AbstractOngoing climate variations in the Arctic and Antarctic pose an apparent paradox. In contrast to the large warming and loss of sea ice in the Arctic in recent decades, Antarctic temperatures and sea ice show little change except for the Antarctic Peninsula. However, model simulations indicate that the Arctic changes have been shaped largely by low-frequency variations of the atmospheric circulation, superimposed on a greenhouse warming that is apparent in model simulations when ensemble averages smooth out the circulation-driven variability of the late 20th century. By contrast, the Antarctic changes of recent decades appear to be shaped by ozone depletion and an associated strengthening of the southern annular mode of the atmospheric circulation. While the signature of greenhouse-driven change is projected to emerge from the natural variability during the present century, the emergence of a statistically significant greenhouse signal may be slower than in other regions. Models suggest that feedbacks from retreating sea ice will make autumn and winter the seasons of the earliest emergence of the greenhouse signal in both Polar Regions. Priorities for enhanced robustness of the Antarctic climate simulations are the inclusion of ozone chemistry and the realistic simulation of water vapour over the Antarctic Ice Sheet.
Alterations in left ventricular function and cardiac biomarkers as a consequence of repetitive endurance cycling
Authors: Williams Karen , Gregson Warren , Robertson Colin , Datson Naomi , Whyte Greg , Murrell Carissa , Wilson Luke , Ainslie Philip , Ross Emma , Shave Rob , Gaze David , George Keith 
Published: March 2009

AbstractThe aim of this study was to assess left ventricular (LV) function and cardiac biomarkers in response to repetitive endurance cycling over 22 days. Ten trained male cyclists (mean±s: age 40±5 years, VO2max 56±4 ml · kg−1 · min−1) completed the 2007 Tour de France route. Before, during, and 2 days after the Tour, all participants underwent an echocardiographic examination to determine ejection fraction, as well as systolic (S′), early diastolic (E′), and late diastolic (A′) myocardial tissue velocities, together with the E′:A′ ratio. Venous blood samples were collected and analysed for cardiac troponin I (cTnI) and B‐type‐natriuretic peptide. Repeated‐measures analysis of variance was used to investigate the cumulative effects of prolonged exercise bouts on LV function and cardiac biomarkers. Alpha was set at 0.05. Although both the ejection fraction (71±2% vs. 59±4%; P<0.05) and the E′:A′ ratio (1.60±0.15 vs. 1.09±0.12; P<0.05) were reduced at post‐stage assessments, there was limited evidence of a progressive decline in either variable over the 22 days. Although post‐tour ejection fraction was not different to baseline (68±3%; P>0.05), the E′:A′ ratio remained depressed (1.37±0.26; P<0.05) following 2 days of recovery. No cTnI was detectable at baseline and B‐type‐natriuretic peptide was within normal ranges (24±7 pg · ml−1). Cardiac troponin I was detectable in at least one cyclist at every assessment, with 60% being positive after stage 15 (range 0.02–0.09 µg · ml−1). B‐type‐natriuretic peptide peaked following stage 17 (240±145 pg · ml−1). In conclusion, repetitive endurance cycling resulted in an acute reduction in LV function and the sporadic appearance of cardiac biomarkers following each day of exercise. Despite this there was no cumulative effect of repetitive exercise. Minor changes in diastolic function persisted up to 48 h of recovery.
Familial syringoma: Report of two cases with a published work review and the unique association with steatocystoma multiplex
Authors: MARZANO Angelo V. , FIORANI Roberta , GIRGENTI Valentina , CROSTI Carlo , ALESSI Elvio 
Published: March 2009

ABSTRACTSyringoma is a benign neoplasm of eccrine origin. Clinically, it manifests as small skin‐colored to yellowish soft papules usually localized around the eyes and on the upper cheeks of middle‐aged women. Familial cases have rarely been reported and may be inherited as an autosomal dominant trait or result from either germ line or somatic mutations. Syringoma can coexist with various conditions, notably Down syndrome. Herein, we report a family with multiple syringomas affecting members of three following generations and describe in detail a 36‐year‐old woman and her 17‐year‐old son. In the latter, steatocystoma multiplex, which is regarded as a benign cystic neoplasm of the folliculosebaceous unit or a nevoid malformation differentiated in the direction of the sebaceous duct, was associated. Acral distribution of steatocystoma multiplex and its presentation as subcutaneous nodules in this patient were unique.
Toxic epidermal necrolysis successfully treated with etanercept
Authors: GUBINELLI Emanuela , CANZONA Flora , TONANZI Tiziano , RASKOVIC Desanka , DIDONA Biagio 
Published: March 2009

ABSTRACTToxic epidermal necrolysis (TEN) is a rare and acute severe adverse reaction to drugs, characterised by massive apoptosis and widespread epidermal and mucosal detachment. Although no gold standard therapy exists, human i.v. immunoglobulins have recently been described as an effective treatment for this disease. We report a case of phenobarbital‐induced TEN in a 59‐year‐old white woman where the epidermal detachment stopped 48 h after beginning the etanercept treatment with complete healing after 20 days. To the best of our knowledge, this is only the second reported case of TEN successfully treated with etanercept.
The familial aggregation of cannabis use disorders
Authors: Merikangas Kathleen R. , Li Julan Julia , Stipelman Brooke , Yu Kelly , Fucito Lisa , Swendsen Joel , Zhang Heping 
Published: March 2009

ABSTRACTAims  The aim of this paper is to examine the familial aggregation of cannabis use disorders and other psychiatric conditions among first‐degree relatives and spouses of probands with a cannabis use disorder.Design  Controlled family study methods.Setting  Out‐patient psychiatric clinics and the local community (same geographic area).Participants  Two hundred and sixty‐two probands with a life‐time history of cannabis use disorder, alcohol dependence, anxiety disorders or no history of any disorder, and their first‐degree relatives and spouses.Measurements  Cannabis use disorders and other DSM‐III‐R disorders in the relatives and spouses using the Schedule for Affective Disorders and Schizophrenia.Findings  Results reveal an elevated risk of life‐time history of cannabis use disorders among siblings [odds ratio (OR: 3.6), adult offspring (OR): 6.9], and spouses (OR: 4.4) of probands with cannabis use disorders. There is a latent familial factor underlying cannabis use disorders that was shared partially with alcohol abuse/dependence. Comorbid mood and anxiety disorders aggregated independently from cannabis use disorders in families. Equal elevation in the magnitude of the association among the first‐degree adult relatives and spouses of probands with a cannabis use disorder suggests the probable contribution of both environmental and genetic factors.Conclusions  These findings support a family‐based approach to drug abuse intervention and the importance of future research concerning environmental mediators of familial transmission of drug abuse.
The clinical safety of long‐term lansoprazole for the maintenance of healed erosive oesophagitis
Authors: FRESTON J. W. , HISADA M. , PEURA D. A. , HABER M. M. , KOVACS T. O. , ATKINSON S. , HUNT B. 
Published: March 2009

SummaryBackground  The clinical safety of long‐term lansoprazole therapy for the maintenance of healed erosive oesophagitis has not been extensively studied in clinical trials.Aim  To assess the long‐term clinical safety of dose‐titrated lansoprazole as maintenance therapy for up to 82 months in subjects with healed erosive oesophagitis.Methods  Clinical safety was assessed by monitoring adverse events (AEs), laboratory data including serum gastrin levels, and endoscopy.Results  Mean duration (± s.d.) of lansoprazole treatment during the titrated open‐label period was 56 ± 24 months (range <1–82 months). Overall, 189 of 195 (97%) subjects experienced a total of 2825 treatment‐emergent AEs. Most AEs occurred during the first year of treatment, were mild‐to‐moderate in severity and resolved while on treatment. Of 155 serious AEs (in 74 subjects), only two (colitis and rectal haemorrhage in one subject) were considered treatment‐related. Sixty‐nine of 195 subjects (35%) experienced 187 treatment‐related AEs, with diarrhoea (10%), headache (8%) and abdominal pain (6%) being the most common. Gastrin levels ≥400 pg/mL were seen in 9% of subjects; hypergastrinemia was not associated with gastro‐intestinal AEs or nodules/polyps.Conclusions  Lansoprazole maintenance therapy for up to 6 years is safe and well tolerated in subjects with healed erosive oesophagitis.
Extramedullary plasmacytoma, a report of five cases diagnosed by FNAC
Authors: Sarin H. , Manucha V. , Verma K. 
Published: March 2009

Objective:  To review cytological findings and diagnostic challenges in the use of fine needle aspiration in the diagnosis of extramedullary plasmacytoma.Methods:  Five cases of extramedullary plasmacytoma that were initially diagnosed on fine needle aspiration cytology over a period of two years in Sir Ganga Ram Hospital were reviewed.Results:  The cytological findings were similar in all five cases. The smears were cellular and composed of plasmacytoid cells arranged singly and in clusters, with varying pleomorphism, bi‐ and multinucleation and mitotic figures. Presence of anaplasia, increased plasmablasts, numerous naked nuclei and unusual location of the tumour were some of the challenges faced during the cytological evaluation.Conclusions:  Extramedullary plasmacytoma may occur either as an initial presentation or as a secondary involvement by multiple myeloma. Fine needle aspiration is a reliable technique for its rapid diagnosis.
Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology
Authors: Handa U. , Chhabra S. , Mohan H. 
Published: March 2009

U. Handa, S. Chhabra and H. Mohan Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytologyObjective:  Plasma cell tumours represent autonomous proliferation of plasma cells and can manifest as multiple myeloma, monoclonal gammopathy of undetermined significance, variants of plasma cell myeloma or plasmacytoma.Methods:  We report 12 cases of plasma cell tumours, which were initially diagnosed as plasmacytoma on fine needle aspiration cytology (FNAC). The patients were further subjected to bone marrow examination, serum electrophoresis, urine examination for Bence–Jones proteins, and x‐ray examination of the skeleton.Results:  The cytological smears from all cases were cellular and showed numerous plasma cells in varying degrees of maturity. Subsequent to investigations, five cases were labelled as multiple myeloma with secondary extramedullary plasmacytoma, three as solitary bone plasmacytoma and two as primary extramedullary plasmacytoma. In the remaining two cases, bone marrow and urine examination findings were not available, so a conclusive diagnosis of multiple myeloma or solitary plasmacytoma could not be made.Conclusion:  The study highlights the role of FNAC in the diagnosis of plasma cell tumours. Subsequent work‐up and follow‐up of these patients is important to rule out the presence of multiple myeloma.
Upward continuation with topographic datuming operator: the integrated wave equation datuming scheme revised
Authors: Yang Kai , Liu Yu‐Zhu , Geng Jian‐Hua , Ma Zai‐Tian 
Published: March 2009

ABSTRACTThe integrated wave equation datuming scheme is an integrated datuming method to implement the wave equation velocity replacement with a one‐way extrapolator for overthrust data. The integrated wave equation datuming scheme is accomplished by downward continuing the data from the topography to a non‐planar base of the weathering layer, followed by an upward continuation from the base of the weathering layer to a final planar datum. Both the downward and the upward continuation are accomplished by a one‐way extrapolator by a classical ‘two‐step’ implementation. The topographic datuming operator is a distinctive technique by which the shots and receivers are downward continued simultaneously. Although its inadaptability to non‐planar datum and the strong lateral variation of the near‐surface structure constrains its application to the downward continuation of the overthrust data, we found that the ‘one‐step’ feature of the topographic datuming operator is extremely suitable for the upward continuation. In this paper, the topographic datuming operator is incorporated into the integrated wave equation datuming scheme to perform upward continuation instead of a one‐way extrapolator – thus a revised integrated wave equation datuming scheme is constructed. Compared with the previous scheme, the computatiol cost of the revised integrated wave equation datuming scheme is greatly reduced, thus the applicability of the integrated wave equation datuming scheme is further improved. The synthetic and real data examples demonstrate its effectiveness and efficiency.
Patterns of mortality for each life‐history stage in a population of the endangered New Zealand stitchbird
Authors: Low Matthew , Pärt Tomas 
Published: March 2009

SummaryUsing data from 396 breeding attempts over an 8‐year period, we investigated age‐ and stage‐specific survival rates and their modifying factors in a closed island population of the New Zealand stitchbird (or hihi,Notiomystis cinctaDu Bus).Survival probability generally increased over time; however, at each life‐history transition, survival in the new stage started lower than at the end of the previous stage, creating a ‘saw‐tooth’ function of age‐related survival.The probability of an egg hatching was low (0·73 ± 0·01): most likely a consequence of genetic bottlenecks previously endured by this population. There was strong support for a positive relationship between hatching rate and the subsequent survival of the female parent, and hatching success declining for females > 4 years old.Nestling survival probability increased as a function of brood size and days since hatching, and decreased relative to daily maximum ambient temperature and hatching date. Support for models including ambient temperature was greater than for other covariates, with the majority of this temperature‐mediated survival effect being restricted to the early nestling stage.Fledglings had low survival rates in the first two weeks after leaving the nest, with post‐fledging survival related to the fledgling's mass. Two months after fledging, juvenile survival probability plateaued and remained relatively constant for the following autumn, winter and spring/summer breeding season. There was no effect of sex or season on adult survival probability. However, there was strong support for age‐specific variation in adult survival, with survival likelihood increasing during the first four years before showing evidence of a senescence decline.Within‐stage survival increases were likely related to stage‐specific selection pressures initially weeding out individuals of poorer phenotypes for the environment specific to each life‐history stage. Such a mechanism explains the initial high mortality at life‐history transitions; a well‐adapted phenotype for one stage may not necessarily be so well adapted for subsequent stages. These patterns are not only valuable for examining life‐history theory, but also for understanding the regulation of vital rates in an endangered species and providing a basis from which better population management models and harvesting regimes can be derived.