bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of search method and age class on mark‐recapture parameter estimation in a population of red‐backed salamanders
Authors: Buderman Frances E. , Liebgold Eric B. 
Published: November 2011

AbstractMark‐recapture methods are generally considered to more accurately reflect population trends than count data, which is especially important for indicator species. Terrestrial salamanders are often used as indicators of forest ecosystem health and may be monitored through diurnal cover object searches or nocturnal activity searches. Our goal was to determine whether search method affected encounter probabilities, whether these probabilities differed between age classes, and whether the inclusion of search method in mark‐recapture models affected abundance estimates. We used program MARK to analyze 3 years of red‐backed salamander (Plethodon cinereus) mark‐recapture data using Pollock's robust design taken from a 144 m2plot. Initial encounter probabilities during night searches were consistently greater than during diurnal cover object searches. As a result, inclusion of search method in models sometimes affected abundance estimates. There was no difference between adult and juvenile encounter probabilities nor were abundance estimates affected by inclusion of age class, but there was yearly variation in the juvenile abundance estimates. For these reasons, we recommend that sampling of terrestrial salamanders include nocturnal activity searches and be conducted over multiple years. Monitoring programs of other species should take into account whether the selected search method(s) may be more likely to sample different subsets of the population of interest and how this may restrict their inferences.
Inhibitory control after traumatic brain injury in children
Authors: Sinopoli Katia J. , Dennis Maureen 
Published: November 2011

AbstractInhibitory control describes a number of distinct processes. Effortless inhibition refers to acts of control that are automatic and reflexive. Effortful inhibition refers to voluntary, goal‐directed acts of control such as response flexibility, interference control, cancellation inhibition, and restraint inhibition. Disruptions to a number of inhibitory control processes occur as a consequence of childhood traumatic brain injury (TBI). This paper reviews the current knowledge of inhibition deficits following childhood TBI, and includes an overview of the inhibition construct and a discussion of the specific deficits shown by children and adolescents with TBI and the factors that mediate the expression of these deficits, including injury‐related variables and the expression of pre‐ and post‐injury attention‐deficit/hyperactivity disorder. The review illustrates that inhibitory control processes differ in terms of measurement, assessment, and neurological underpinnings, and also that childhood TBI may selectively disrupt particular forms of inhibition.
RNA interference inCaenorhabditis elegans: Uptake, mechanism, and regulation
Authors: ZHUANG JIMMY J. , HUNTER CRAIG P. 
Published: November 2011

SUMMARYRNA interference (RNAi) is a powerful research tool that has enabled molecular insights into gene activity, pathway analysis, partial loss-of-function phenotypes, and large-scale genomic discovery of gene function. While RNAi works extremely well in the non-parasitic nematodeC. elegans, it is also especially useful in organisms that lack facile genetic analysis. Extensive genetic analysis of the mechanisms, delivery and regulation of RNAi inC. eleganshas provided mechanistic and phenomenological insights into why RNAi is so effective in this species. These insights are useful for the testing and development of RNAi in other nematodes, including parasitic nematodes where more effective RNAi would be extremely useful. Here, we review the current advances inC. elegansfor RNA delivery methods, regulation of cell autonomous and systemic RNAi phenomena, and implications of enhanced RNAi mutants. These discussions, with a focus on mechanism and cross-species application, provide new perspectives for optimizing RNAi in other species.
Evaluation of animal and public health surveillance systems: a systematic review
Authors: DREWE J. A. , HOINVILLE L. J. , COOK A. J. C. , FLOYD T. , STÄRK K. D. C. 
Published: November 2011

SUMMARYDisease surveillance programmes ought to be evaluated regularly to ensure they provide valuable information in an efficient manner. Evaluation of human and animal health surveillance programmes around the world is currently not standardized and therefore inconsistent. The aim of this systematic review was to review surveillance system attributes and the methods used for their assessment, together with the strengths and weaknesses of existing frameworks for evaluating surveillance in animal health, public health and allied disciplines. Information from 99 articles describing the evaluation of 101 surveillance systems was examined. A wide range of approaches for assessing 23 different system attributes was identified although most evaluations addressed only one or two attributes and comprehensive evaluations were uncommon. Surveillance objectives were often not stated in the articles reviewed and so the reasons for choosing certain attributes for assessment were not always apparent. This has the potential to introduce misleading results in surveillance evaluation. Due to the wide range of system attributes that may be assessed, methods should be explored which collapse these down into a small number of grouped characteristics by focusing on the relationships between attributes and their links to the objectives of the surveillance system and the evaluation. A generic and comprehensive evaluation framework could then be developed consisting of a limited number of common attributes together with several sets of secondary attributes which could be selected depending on the disease or range of diseases under surveillance and the purpose of the surveillance. Economic evaluation should be an integral part of the surveillance evaluation process. This would provide a significant benefit to decision-makers who often need to make choices based on limited or diminishing resources.
Viral respiratory infections during the 2009 influenza A(H1N1) outbreak in the West Midlands Region, UK
Authors: TANNER H. E. , CURRAN M. D. , BOXALL E. H. , OSMAN H. 
Published: November 2011

SUMMARYIn spring 2009 a new strain of influenza A(H1N1) emerged and caused a worldwide pandemic. This study utilized a large collection of respiratory specimens from suspected cases of influenza A(H1N1) in the UK West Midlands during the pandemic in order to investigate which other respiratory viruses were circulating and whether they played any role in the increased hospitalization rates seen during that period. Study specimens were selected from community and hospitalized patients positive and negative for influenza A(H1N1) and tested by PCR for other respiratory viruses. A number of infections diagnosed as influenza during the summer influenza outbreak were found to be due to other virus infections (most commonly rhinovirus). No statistically significant difference was found between the rates of respiratory virus co-infection with H1N1 in patients from community or hospital locations suggesting underlying factors were likely to be more significant than viral co-infections in determining severity of influenza A(H1N1) disease.
Cytochrome P450‐catalysed reactive oxygen species production mediates the (−)schisandrin B‐induced glutathione and heat shock responses in AML12 hepatocytes
Authors: Leong Pou Kuan , Chiu Po Yee , Leung Hoi Yan , Ko Kam Ming 
Published: November 2011

AbstractSch B (schisandrin B), the most abundant dibenzocyclooctadiene lignan in Fructus schisandrae, can induce glutathione antioxidant and heat shock responses, as well as protect against oxidant‐induced injury in various tissues, including the liver in rodents and AML12 (alpha mouse liver 12) hepatocytes. (−)Sch B is the most potent stereoisomer of Sch B in its cytoprotective action on AML12 hepatocytes. To define the role of ROS (reactive oxygen species) arising from CYP (cytochrome P450)‐catalysed metabolism of (−)Sch B in triggering glutathione antioxidant and heat shock responses, the effects of a CYP inhibitor [ABT (aminobenzotriazole)] and antioxidants [DMTU (dimethylthiouracil) and TRX (trolox)] on (−)Sch B‐induced ROS production and associated increases in cellular GSH level, as well as Hsp25/70 (heat‐shock protein 25/70) production, were investigated in AML12 hepatocytes. The results indicated that (−)Sch B causes a dose dependent and sustained increase in ROS production over 6 h in AML12 hepatocytes, which was completely suppressed by pre‐/co‐treatment with ABT or DTMU/TRX. Incubation with (−)Sch B for 6 h caused optimal and dose‐dependent increases in cellular GSH level and Hsp25/70 production at 16 h post‐drug exposure in AML12 hepatocytes. These cellular responses were associated with protection against menadione‐induced apoptosis. Pre‐/co‐treatment with ABT or antioxidants completely abrogated the (−)Sch B‐induced glutathione antioxidant and heat shock responses, as well as protection against menadione‐induced apoptosis. Experimental evidence obtained thus far supports the causal role of ROS arising from the CYP‐catalysed metabolism of (−)Sch B in eliciting glutathione antioxidant and heat shock responses in AML12 hepatocytes.
Biogeographic patterns in scaled chrysophytes from the east coast of North America
Authors: SIVER PETER A. , LOTT ANNE M. 
Published: November 2011

Summary1. We assessed the distribution of scaled chrysophytes in fresh waters along 3200 km of the east coast of North America (29° to 48°N) to determine any biogeographic patterns in relation to chemical, physical, climatic and spatial variables.2. Scaled chrysophytes were identified using scanning electron microscopy and counted from 264 waterbodies in nine regions (20 subregions). Eighteen chemical, physical and climate variables were determined for each waterbody. We used Sorensen’s similarity index and analysis of similarity (ANOSIM) to evaluate whether the floras differed between regions, subregions, glaciated and non‐glaciated areas, as well as within sets of waterbodies with similar chemical and physical characteristics but situated in different regions. Distance‐based linear modelling (DISTLM) was used to evaluate the relative importance of the chemical, physical and climate factors in explaining the variability in the assemblages of scaled chrysophytes, and the resulting models were visualised using redundancy analysis (RDA).3. Significant differences in the flora were found between all regions and most subregions, and between glaciated and non‐glaciated areas. Significant differences were also recorded between waterbodies with similar chemical and physical characteristics but situated in different regions. Many species were abundant along specific sections of the latitudinal gradient, but lacking from others. A set of environmental variables explained significant and independent portions of the variation in scaled chrysophytes, with pH and mean minimum July temperature accounting for 20% of the total.4. The distribution of scaled chrysophytes along the east coast of North America is not homogeneous and there are biogeographic patterns, despite apparent dispersal mechanisms (migratory birds and wind events) that might act to reduce differences between regions. Rather, differences exist even between neighbouring subregions containing sites with statistically similar chemical and physical attributes. Environmental variables clearly play a significant role in determining whether species will inhabit a given site. However, species were not always found in waterbodies likely to support growth, implicating inadequate dispersal, poor transportability or both.
Voltage dependence of the tunnelling current: An exact expression
Authors: Noguera Claudine 
Published: November 2011

SUMMARYAn exact expression for the tunnelling current measured with a scanning tunnelling microscope (STM) is obtained. It clarifies the information deducible from the ‘spectroscopic mode’ of the STM and raises the question of the observability of surface states. The connection with the Transfer Hamiltonian approach is made, and the conditions of validity of the latter are analysed.
Single‐electron effects observed with a low‐temperature STM
Authors: van Bentum P. J. M. , van de Leemput L. E. C. , Smokers R. T. M. , van Kempen H. 
Published: November 2011

SUMMARYWe have used a low‐temperature scanning tunnelling microscope to study the effect of the Coulomb charging energy on the tunnelling behaviour of low capacitance point‐contact junctions. The tunnelling I‐V characteristics between a tungsten tip and various materials, such as stainless steel, aluminium, carbon and YBa2Cu3O7‐δ, show a quadratic behaviour at low voltages and a displaced asymptotic behaviour at high voltages. The I‐V characteristics can be quantitatively understood using the model of single‐electron tunnelling induced by the Coulomb blockade. The capacitances of this type of point‐contact tunnel junctions are in the 10−18 F range, and are adjustable by varying the distance between tip and surface. These capacitances are at least two orders of magnitude lower than can presently be achieved by electron lithography.In a series configuration of two low‐capacitance tunnel junctions, with an isolated small particle as a common electrode, we have observed the so‐called Coulomb staircase, due to the quantization of the charge on a single small particle.The experimental results are in good agreement with semi‐classical Monte‐Carlo simulations.The low capacitance of an STM assembly can cause a serious complication in the interpretation of low temperature spectroscopic data. We will discuss the implications for the measurements on superconductors, and for the case of inelastic tunnelling spectroscopy.
An exact calculation of the voltage‐dependent tunnelling current in simple one‐dimensional models: Comparison with the Bardeen perturbation approach
Authors: Sacks W. S. , Noguera C. 
Published: November 2011

SUMMARYIn this paper we present an exact calculation of the tunnelling current for two different one‐dimensional barrier potentials. The purpose is twofold: First, we demonstrate the feasibility of applying the new method of C. Noguera as a direct analytical tool for solving tunnelling problems in the case of independent electrons. In this approach, the tunnelling current is expressed in terms of the logarithmic derivative of the Green's function which must be evaluated at the cutting surface. This can be done analytically in the one‐dimensional case. Secondly, we compare these results with the corresponding tunnelling current obtained using the Bardeen perturbation method, valid only in the large barrier limit. In particular, we investigate the use of the Bardeen approach in describing tunnelling spectroscopy. The dynamic conductance dI/dV, as a function of bias and barrier width, is compared in both cases.
A small scanning tunnelling microscope with large scan range for biological studies
Authors: Emch R. , Descouts P. , Niedermann Ph. 
Published: November 2011

SUMMARYWe have developed a scanning tunnelling microscope specially designed for biological applications presenting some new features: the scanner tube is mounted parallel to the surface of the sample which enables a high resolution optical microscope to be brought close to the sample when working in air or liquids. The maximum scan range is 5×20 μm with a vertical range of 20 μm and the total size of the system does not exceed 10×40 mm. The piezo‐sensitivity of the scanner tube versus applied voltage was analysed by interferometry measurements and by using scanning tunnelling microscopes. We found a value for the piezoelectric constant d13 of −1·71 Å/V at low voltages (under a few volts) going up to −2 Å/V for higher voltages. Large‐scale images of a carbon grid showed a surprisingly good linearity of the scanner tube.
Imaging of granular high‐Tc thin films using a scanning tunnelling microscope with large scan range
Authors: Niedermann Ph. , Fischer Ø. 
Published: November 2011

SUMMARYSTM images are presented in the micron scale, taken in UHV with a single‐tube scanner STM with SEM control of the tip position. For calibration, a carbon grid was used from which the coupling of x and y scan axes has been determined as well as the piezo‐sensitivity factors. Images taken of a YBa2Cu3O7‐δ, film display the granular structure of the crystallites formed during the post‐evaporation annealing. A direct comparison of STM scans with SEM micrographs was made which demonstrates the complementary information obtained by the two methods. The obtained resolution is compared to the tip shape which becomes crucial for the imaging of corrugated surfaces on the micron scale. With a simple geometric model, an attempt has been made to reconstruct the surface topography from STM scans based on the knowledge of the tip shape.
I.—IMPROVED IMAGE ILLUMINATION AND CONTRAST WITH THE METALLURGICAL MICROSCOPE
Authors: Taylor E. Wilfred 
Published: November 2011

Abstract.The practice of coating glass surfaces in order to reduce the reflected and increase the transmitted light is now well known, but little attention has so far been given to the particular problems presented by the microscope objective. It will be shown that much can be done to improve observing conditions when a cover‐glass illuminator is used, and in this connection the requirements of the metallurgist will receive special consideration. It will be shown that the coating of glass surfaces may result in a marked diminution of fogging light and to enhanced contrast in the image, and also in the more efficient operation of tbe cover‐glass illuminator.
“OPTICAL MEMBRANES”: A COMMON ARTEFACT
Authors: Oettlé A. G. 
Published: November 2011

SYNOPSIS.A common group of optical artefacts is described in which regions of phase or amplitude change in the object appear in sharp outline in the image, where they may be misinterpreted and regarded as evidence of the presence of actual membranes. It is shown that these appearances are always encountered with dark‐ground illumination, of both types, oblique and central, provided the object is large enough to be resolved. Similar effects can also be obtained with bright‐ground illumination and various phase‐contrast methods.With phase‐retarding objects in positive phase‐contrast, the appearance of a black outline to image detail is seen when reversal of contrast occurs. This is seen when the object produces higher phase change than the optimum for the particular system. This optimum depends on the ratio of direct to diffracted light: the less direct light is transmitted, the lower is the optimum range of phase change in the object.
VARIABLE DARK‐GROUND ILLUMINATION
Authors: Hartley W. G. 
Published: November 2011

SYNOPSIS.By exploiting the property of polarization, the intensity of the light directly entering an objective can be controlled, so that the illumination of the specimen may be adjusted between critical bright and dark field conditions.The use of a suitable Polaroid substage stop in conjunction with an analyser is described, discussed, and also the conversion of an immersion paraboloid to this use. Bn &‐focal illuminating system of 0.86 N.A., suitable for this and a variety of other uses, is also described
THE DEVELOPMENT OF THE RAT SPERMATID
Authors: Austin C. R. , Sapsford C. S. 
Published: November 2011

SYNOPSIS.The stages of development of the rat spermatid as seen with the phase‐contrast microscope are described and illustrated. The process as thus discerned is generally consistent with previous accounts, but differs in certain particulars.The short dark rods in the Golgi apparatus of the early spermatids form a U‐shaped structure at later stages.The bead deposited by the Golgi apparatus upon the surface of the nucleus is developed by the coalescence of three or four small beads or granules which make their appearance in the Golgi apparatus.The axial filaments of the early spermatids are generally seen entirely confined within the cytoplasm and often exhibit vigorous motility in this situation.Three centrioles are seen for a limited period of spermatid development.The transformation of the spermatid nucleus into the sperm head occurs by a process of lateral development and not by anterior extension.The meaning of the terms “acrosome” and “perforatorium” is discussed. It is considered that the rod (“acrosome”) is a thickened part of the head‐cap, and that the bead probably does not contribute directly to the formation of the rod.The mature sperm head is composed of four major parts—nucleus, rod, vesicle, and head‐cap. It is suggested that the vesicle lying near the tip of the head may carry an active agent for the penetration of the zona pellucida.
III.—OBSERVATIONS ON MICROSCOPE CONDENSERS, OBJECTIVES, AND EYEPIECES.: III. Microscope Eyepieces
Authors: Payne B. O. 
Published: November 2011

SYNOPSIS.The requirements for microscope eyepieces for visual use are considered and the possibilities of achieving them are discussed in relation to the conditions under which the system is required to work. Eyepieces of various types for both visual and photomicrographic purposes are described and illustrated.
VI.—RHABDOMYOSARCOMAS IN THE ALBINO RAT
Authors: Haddow A. , Timmis G. M. , Horning E. S. 
Published: November 2011

SYNOPSIS1. Out of a total of twenty Albino rats one male and one female developed rhabdomyosarcoma during treatment with 5‐β‐naphthyl‐2: 4: 6‐triaminoazopyrimidine.2. The primary striated muscle tumour which arose in either the spermatic cord or the epididymis of the male rodent formed metastases in most organs of the body. Dissemination appears to have taken place via the lymphatic pathway.3. The histology of these tumours has been described in detail and problems relating to the ætiology and behaviour of these rare growths have been discussed.
VII.—PHOTOMICROGRAPHY WITH THE BURCH REFLECTING MICROSCOPE
Authors: King R. J. , Roe E. M. F. 
Published: November 2011

SYNOPSISA brief survey of the characteristics of reflecting microscopes is given, with particular reference to the Burch microscope. Accessory optical equipment for photomicrography with this microscope in the visible and ultra‐violet is described, and the adjustment of the objective and condenser mirror pairs is discussed. Some typical photomicrographs are shown.
IX.—AN IMPROVED PHASE‐CONTRAST MICROSCOPE WITH VARIABLE AMPLITUDE AND PHASE DIFFERENCE
Authors: Payne B. O. 
Published: November 2011

SYNOPSISAn instrument is described in which the back focal plane of the objective is re‐imaged into a more accessible position by the aid of a concave mirror without the introduction of any additional air‐glass interfaces. As a result, interchange of phase plates is greatly facilitated and amplitude and phase variation can be achieved efficiently at all powers.
THE MANUFACTURE AND TOLERANCING OF SCREW THREADS ON OPTICAL COMPONENTS, WITH SPECIAL REFERENCE TO THE R.M.S. MICROSCOPE OBJECTIVE AND NOSEPIECE THREADS
Authors: Nickols L. W. 
Published: November 2011

SYNOPSISA review is made of the current practice and problems of manufacturing and gauging screw threads of fine pitch on optical components. Comments are made on a recent United States draft Standard for microscope objective and nosepiece threads. Finally, recommendations are made for the revision of the R.M.S. Standard for microscope objective and nosepiece threads.
RECENT OBSERVATIONS BY LIGHT AND ELECTRON MICROSCOPY ON THE CYTOPLASMIC INCLUSIONS OF THE NEURONES OF PATELLA VULGATA
Authors: Lacy D. , Rogers G. E. 
Published: November 2011

SYNOPSISA preliminary report is given of observations made on the neurones of the pedal ganglia of Patella vulgata. Three types of cytoplasmic inclusions have been seen in these cells—mitochondria, lipochondria, and Golgi apparatus. The dictyosomes described by other workers probably correspond to pairs of Golgi membranes together with the dense (osmiophilic) substance they enclose. The archoplasm probably corresponds to numerous small Golgi vesicles.