bluuebunny/crossref_metadata_2025 huggingface dataset:
SEM sample preparation for cells on 3D scaffolds by freeze‐drying and HMDS
Authors: Lee Juliana Tsz Yan , Chow King Lau
Published: August 2011

Common dehydration methods of cells on biomaterials for scanning electron microscopy (SEM) include air drying, hexamethyldisilazane (HMDS) or tetramethysilane (TMS) treatment and critical point drying (CPD). On the other side, freeze‐drying has been widely employed in dehydrating biological samples and also in preparing porous biomaterial scaffolds but not in preparing cells on three‐dimensional (3D) biomaterials for SEM examination. In this study, we compare cells on porous hydroxyapatite (HA) prepared by air drying, HMDS and freeze‐drying. The effects of fixation and using phosphate buffered saline (PBS) in the fixation were also assessed on three porous calcium phosphate (CaP) materials, namely, HA, α‐tricalcium phosphate (α‐TCP) and β‐tricalcium phosphate (β‐TCP) samples. There is no significant difference in samples prepared by HMDS treatment and freeze‐drying viewed at low magnification. Besides, it is better not to use phosphate buffer in the fixation step for CaP materials to avoid undesirable spontaneous precipitation of CaPs. On the other hand, fewer exchanges of liquids are required for freeze‐drying and hence chemical fixation may not be absolutely required for samples prepared by freeze‐drying. Other technical details of the preparation were also investigated and discussed. This study suggests both HMDS and freeze‐drying can be employed to dehydrate cells on 3D scaffolds for SEM examination. SCANNING 34: 12–25, 2012. © 2011 Wiley Periodicals, Inc.
Enhancing directory virtualization to detect insider activity
Authors: Claycomb William , Shin Dongwan , Ahn Gail‐Joon
Published: August 2011

One of the critical yet lingering issues in computer security is insider threat, and it often takes advantage of some security services based on directory services such as authentication and access control. Detecting these threats is quite challenging because malicious users with the technical ability to leverage these services often have sufficient knowledge and expertise to conceal unauthorized activity. In this article, we present an approach using directory virtualization to monitor various systems across an enterprise for the purpose of detecting malicious insider activity. Specifically, a policy engine that leverages directory virtualization services is proposed to enhance monitoring and detecting capabilities by allowing greater flexibility in analyzing changes for malicious intent. The resulting architecture is a system‐based approach, where the relationships and dependencies between data sources and directory services are used to detect an insider threat, rather than simply relying on point solutions. This paper presents such an architecture in detail, including a description of implementation results. Copyright © 2011 John Wiley & Sons, Ltd.
Stable structure and effects of sulfur in CdTe/CdS heterojunctions
Authors: Wang Jianli , Tang Gang , Wu X.S. , Gu Mingqiang
Published: August 2011

Structural and electronic properties of S in the CdTe/CdS(0001) interface are studied using the density functional theory. The interstitial S atom may induce the inversion of the surface Cd atoms and sublayer Te atoms of the Cd‐terminated surface, while S atoms may adsorb at the top sites, substitute Te atoms or accumulate at the voids inside the Te‐terminated (111) CdTe surface. Isovalent substituting S for Te in the CdTe(111)/CdS(0001) heterojunctions can reduce the strain arising from lattice mismatch and cause a reduction of interface states, so it may be better for solar cells. Copyright © 2011 John Wiley & Sons, Ltd.
Global software engineering and agile practices: a systematic review
Authors: Jalali Samireh , Wohlin Claes
Published: August 2011

Agile practices have received attention from industry as an alternative to plan‐driven software development approaches. Agile encourages, for example, small self‐organized collocated teams, whereas global software engineering (GSE) implies distribution across cultural, temporal, and geographical boundaries. Hence, combining them is a challenge. A systematic review was conducted to capture the status of combining agility with GSE. The results were limited to peer‐reviewed conference papers or journal articles, published between 1999 and 2009. The synthesis was made through classifying the papers into different categories (e.g. publication year, contribution type, research method). At the end, 81 papers were judged as primary for further analysis. The distribution of papers over the years indicated that GSE and Agile in combination has received more attention in the last 5 years. However, the majority of the existing research is industrial experience reports in which Agile practices were modified with respect to the context and situational requirements. The emergent need in this research area is suggested to be developing a framework that considers various factors from different perspectives when incorporating Agile in GSE. Practitioners may use it as a decision‐making basis in early phases of software development. Copyright © 2011 John Wiley & Sons, Ltd.
A Generic Polymorphic Unicast Routing Protocol for vehicular ad hoc networks
Authors: Mnaouer Adel Ben , Foh Chuan Heng , Chen Lei
Published: August 2011

In this work, we present a new generic polymorphic routing protocol tailored for vehicular ad hoc networks (VANETs). Similar to the case of mobile ad hoc networks, the routing task in VANETs comes under various constraints that can be environmental, operational, or performance based. The proposed Polymorphic Unicast Routing Protocol (PURP) uses the concept of polymorphic routing as a means to describe dynamic, multi‐behavioral, multi‐stimuli, adaptive, and hybrid routing, that is applicable in various contexts, which empowers the protocol with great flexibility in coping with the timely requirements of the routing tasks. Polymorphic routing protocols, in general, are equipped with multi‐operational modes (e.g., grades of proactive, reactive, and semi‐proactive), and they are expected to tune in to the right mode of operation depending on the current conditions (e.g., battery residue, vicinity density, traffic intensity, mobility level of the mobile node, and other user‐defined conditions). The objective is commonly maximizing and/or improving certain metrics such as maximizing battery life, reducing communication delays, improving deliverability, and so on. We give a detailed description and analysis of the PURP protocol. Through comparative simulations, we show its superiority in performance to its peers and demonstrate its suitability for routing in VANETs. Copyright © 2011 John Wiley & Sons, Ltd.
Bayesian modeling for large spatial datasets
Authors: Banerjee Sudipto , Fuentes Montserrat
Published: August 2011

We focus upon flexible Bayesian hierarchical models for scientific data available at geo‐coded locations. Investigators are increasingly turning to spatial process models to analyze such datasets. These models are customarily estimated using Markov Chain Monte Carlo (MCMC) methods, which have become especially popular for spatial modeling, given their flexibility and power to fit models that would be infeasible otherwise. However, estimating Bayesian spatial process models is undermined by prohibitive computational expenses associated with parameter estimation. Classes of low‐rank spatial process models are increasingly being deployed to resolve this problem by projecting spatial effects to a lower‐dimensional subspace. We discuss how a low‐rank process called the ‘predictive process’ seamlessly enters the hierarchical modeling framework and helps us accrue substantial computational benefits.WIREs Comp Stat2012, 4:59–66. doi: 10.1002/wics.187

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory

Data: Types and Structure > Image and Spatial Data

Statistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)

Data: Types and Structure > Image and Spatial Data
Catheter Fracture of Intravenous Ports and its Management
Authors: Wu Ching‐Yang , Fu Jui‐Ying , Feng Po‐Hao , Kao Tsung‐Chi , Yu Sheng‐Yueh , Li Hao‐Jui , Ko Po‐Jen , Hsieh Hung‐Chang
Published: August 2011

Background

Intravenous ports are widely used for oncology patients. However, catheter fractures may lead to the need for re‐intervention. We aimed to identify the risk factors associated with catheter fractures.

Methods

Between January 1 and December 31, 2006, we retrospectively reviewed the clinical data and plain chest films of 1,505 patients implanted with an intravenous port at Chang Gung Memorial Hospital. Different vascular sites were compared using the chi‐square or Fisher’s exact test for categorical variables, and the t test was used for continuous variables with normal distribution; P < 0.05 was considered statistically significant.

Results

There were 59 and 1,448 procedures in the fracture and non‐fracture groups, respectively. Monovariate analysis revealed that the risk factors for catheter fracture were as follows: large angle (P < 0.0001), female gender (P < 0.0008), subclavian route (P < 0.0001), and port type Arrow French (Fr.) 8.1 (P < 0.0001). Because these risk factors showed no interaction effects, they were all considered independent risk factors. When all factors were considered together, all risk factors, except angle and age, retained their statistical significance.

Conclusions

Most catheter fractures were caused by material weakness. If catheter fracture is confirmed, further intervention for port and catheter removal is recommended. Female gender, intravenous port implantation via the subclavian route, and the Arrow Fr. 8.1 port were found to be risk factors. Patients with these risk factors should be monitored closely to avoid catheter fractures.
Extending the Place Glacier mass-balance record to AD 1585, using tree rings and wood density
Authors: Wood Lisa J. , Smith Dan J. , Demuth Michael N.
Published: August 2011

Recognizing that climate influences both annual tree-ring growth and glacier mass balance, changes in the mass balance of Place Glacier, British Columbia, were documented from increment core records. Annually resolved ring-width (RW), maximum (MXD), and mean density (MD) chronologies were developed from Engelmann spruce and Douglas-fir trees sampled at sites within the surrounding region. A snowpack record dating to AD 1730 was reconstructed using a multivariate regression of spruce MD and fir RW chronologies. Spruce MXD and RW chronologies were used to reconstruct winter mass balance (Bw) for Place Glacier to AD 1585. Summer mass balance (Bs) was reconstructed using the RW chronology from spruce, and net balance was calculated from Bw and Bs. The reconstructions provide insight into the changes that snowpack and mass balance have undergone in the last 400 years, as well as identifying relationships to air temperature and circulation indices in southern British Columbia. These changes are consistent with other regional mass-balance reconstructions and indicate that the persistent weather systems characterizing large scale climate-forcing mechanisms play a significant glaciological role in this region. A comparison to dated moraine surfaces in the surrounding region substantiates that the mass-balance shifts recorded in the proxy data are evident in the response of glaciers throughout the region.
Myths and Rituals: A General Theory
Authors: Kluckhohn Clyde
Published: August 2011

Nineteenth century students strongly tended to study mythology apart from associated rituals (and indeed apart from the life of the people generally). Myths were held to be symbolic descriptions of phenomena of nature. One prominent school, in fact, tried to find an astral basis for all mythic tales. Others, among whom Andrew Lang was prominent, saw in the myth a kind of primitive scientific theory. Mythology answered the insistent human How? and Why? How and why was the world made? How and why were living creatures brought into being? Why, if there was life must there be death? To early psychoanalysts such as Abraham and Rank myths were “group phantasies,” wish-fulfillments for a society strictly analogous to the dream and day-dream of individuals. Mythology for these psychoanalysts was also a symbolic structure par excellence, but the symbolism which required interpretation was primarily a sex symbolism which was postulated as universal and all-pervasive. Reik recognized a connection between rite and myth, and he, with Freud, verbally agreed to Robertson Smith's proposition that mythology was mainly a description of ritual. To the psychoanalysts, however, mythology was essentially (so far as what they did with it is concerned) societal phantasy material which reflected impulse repression. There was no attempt to discover the practical function of mythology in the daily behaviors of the members of a society nor to demonstrate specific interactions of mythology and ceremonials.
Paradise Lost
Authors: McColley Grant
Published: August 2011

Among the significant questions perennially raised by Miltonic criticism, the two most important are the two most variously answered: What is Paradise Lost, and why did Milton write it? If the evidence which follows may be regarded as sufficiently exhaustive, I suggest that Paradise Lost was designed as a non-sectarian epic and more or less deliberately modelled as well as based upon conservative religious literature. The second conclusion is that Milton wrote his greatest poem to justify the ways of the Christian God, and to give artistic-prophetic expression to beliefs which were both vital and sacred to him.
Evidences of Christianity in Egypt during the Roman Period
Authors: Bell H. I.
Published: August 2011

The diffusion of Christianity during the first two centuries and a half of its existence is a subject as full of interest as it is beset with problems and difficulties. Curiously enough, there are few provinces of the Roman Empire concerning which our evidence, in this respect, is more unsatisfactory than Egypt, about which we might expect to be particularly well informed. From Egypt we have not only the usual crop of inscriptions (which, being of a public nature, cannot be expected to be very informative here) but a vast mass of papyri, more abundant for the second century than for any other, and quite plentiful for the third. And these would seem to be precisely the sort of material which we require. They are selected by no official process of sifting but by the mere accidents of preservation and discovery, they include documents of every kind, and they touch all classes of society, in town and country. Official documents and legal contracts are not, indeed, likely to yield much evidence; but on the private letters and perhaps the accounts, possibly even the wills, Christianity should, one would think, have left some trace.
Ghevond's Text of the Correspondence between ʻUmar II and Leo III
Authors: Jeffery Arthur
Published: August 2011

There is a persistent tradition in the Eastern Christian Churches, often referred to by Oriental Christians even at the present day, to the effect that early in the VIIIth century there was an exchange of letters on the question of the respective merits of Christianity and Islam, between the Umayyad Caliph ʻUmar II (717–720) and the Byzantine Emperor Leo III, the Isaurian (717–741), in which the Emperor gloriously refuted the claims of Islam. If this is so, it will represent one of the earliest documents in the Muslim-Christian Controversy known to us. Carl Güterbock rightly states that the beginnings of literary discussions concerning Islam among the Greeks can be traced back to the middle of the VIIIth century, when Leo III was succeeded by his son Constantine V (741–775), but he begins his account of the Byzantine polemists with John of Damascus (†754) and his pupil Theodore Abū Qurra (c. 825). A polemical epistle of Leo III to ʻUmar must have been written before 720, and would thus be earlier than any known Byzantine tractate on this controversy.
The Basic Aspect of Hittite Religion
Authors: Furlani Giuseppe
Published: August 2011

The religions of ancient Western Asia, though presenting in detail a number of differences, agree in their conception of the relation between man and god. This is the same relation that exists between the servant and his master, or between the subject and his king or prince. According to the religions of ancient Western Asia, man had to serve his god, his king and his master, and this service constituted his religion. In fact, man was created solely to serve god, and all his life therefore was but a series of religious acts in the service of his god. The religious texts of all palaeo-oriental nations afford us ample proofs that this was the fundamental principle of their religion. I refer to Semitic nations, that is, to those who spoke Semitic languages, or to peoples of other tongues: the Sumerians or the Phoenicians, the Hittites or the South Arabs. All these saw divinity in masters, princes, or kings who had man as subject or servant.
The Amphibolous Terms in Aristotle, Arabic Philosophy and Maimonides
Authors: Wolfson Harry Austryn
Published: August 2011

In Arabic philosophic texts, and following them also in Hebrew philosophic texts, restatements of Aristotle's distinction between ‘equivocal’ (ὁμώνυμα, mushtarakah) and ‘univocal’ (συνώνυμα, mutawāṭi'ah), terms usually contain another type of term which stands midway between these two. It is called ‘ambiguous’ or ‘amphibolous’ (mushakkikah) terms. So far no adequate explanation as to the origin of this type of term has been advanced. In the latest and most important study of the subject, the problem of its origin has been left unsolved. To solve this problem as well as to account for the various treatments of ambiguous terms in Arabic philosophy, including Alfarabi, Avicenna, Algazali, Averroes and Maimonides, is the purpose of this paper.
Aristotle and the Jewish Sage According to Clearchus of Soli
Authors: Lewy Hans
Published: August 2011

Among the Greek documents concerning Jews the tale told by Josephus in the name of Clearchus of Soli deserves special attention. This account, in which Clearchus describes the meeting of his master Aristotle with a Jewish sage, contains not only the earliest information about personal acquaintance between a Greek and a Jew, but also raises general interest by the personality of the Western representative. Josephus has omitted to report upon the subject of their discourse, although it would have been worth while to relate the words exchanged between the “maestro di color' che sanno” and one of the ἐκλεκτοὶ πιστοὶ `Eβραῖοι.
The Figure of Loki in Germanic Mythology
Authors: Cawley Frank Stanton
Published: August 2011

Iceland, that island of marvels, has preserved for us, as it has done in most other fields of Germanic culture, nearly all of what we know about the religion of our pagan ancestors. The two Eddas, the Elder (Poetic) and the Younger (Prose) Edda, furnish the whole body of coherent mythology accessible to us. As for the cults themselves, we are much less well informed, but such knowledge as we have is drawn mainly from the Sagas, prose tales dealing with men and events, real and fictitious, of the heathen time, written down two or three centuries after the adoption of Christianity as the state religion in the year 1000, yet seeking to give a faithful picture of the manners and beliefs of the old days, and with scarcely a trace of the intolerance which almost obliterated the pagan traditions in other parts of Germanic territory. The distribution and popularity of the cults, their relative age and gradual expansion have been revealed by the brilliant researches of Professor Magnus Olsen on the Norwegian place-names and by the subsequent studies inspired by his work.
Caeli Enarrant
Authors: Pease Arthur Stanley
Published: August 2011

Every diligent reader of ancient literature has encountered, sooner or later, evidences of belief in teleology, the doctrine of the deliberate adaptation of the phenomena of organic life (and even of those of the inorganic celestial system) to some definite end or purpose, as opposed, on the one hand, to the effects of blind chance, and, on the other, to those of a merely automatic survival of the fittest and the elimination of the unfit. Further, from reflection upon phenomena susceptible of teleological explanation, thinkers, both classical and oriental, alike ancient and modern, have not unnaturally passed to a belief that the existence of orderly or purposeful creations necessarily demands the existence of an ordering and purposing Creator.
Simon Alcok on Expanding the Sermon
Authors: Boynton Mary Fuertes
Published: August 2011

‘The foundation in the thirteenth century of the two great orders of Franciscans and Dominicans, the latter par excellence the ordo praedicatorum, gave an enormous impulse to preaching.’ It was largely responsible for the abundant production of sermons and arts of sermon-making in the centuries that follow. More than two hundred manuscripts of the period from 1200 to 1500 contain arts of preaching, artes praedicandi. Some have been traditionally associated with the names of certain great Churchmen and Schoolmen, St. Bonaventure, St. Thomas, Albert the Great; we have the names of nineteen authors in the thirteenth century, thirty-six in the fourteenth, twenty-seven in the fifteenth, and as many more manuscripts are anonymous. A glance at Professor Caplan's list of authors on pages 38, 39, of his Hand-List will show that the great majority of known authors were members of an Order.
A Latin Hymn to the Creator Ascribed to Plato
Authors: Lewy Hans
Published: August 2011

A hymn to the Creator ascribed to Plato deserves attention, even if both form and content show clearly that it is of much later date. Such a poem is preserved in the Anthologia Latina, where it is introduced as a translation from Greek made by “a certain Tiberianus.” This interesting document, in thirty-two verses, may be translated as follows:

“Almighty, borne by age-old heavens, amid Thy myriad virtues Thou art ever One, and no one can measure Thee with number or with time. Now (if by any name it is meet to invoke Thee) Thou shalt be invoked by the unknown name in which Thou, the Holy One, dost rejoice, whereat the mighty earth trembles, and the wandering stars stand in their swift course. Thou art One and likewise Many, Thou art First and Last, Thou art at once the Center and the Survivor of the universe. For Thou art without end, yet Thou bringest an end to the swift passage of time, and on high, from eternity, Thou dost behold harsh fate swept on with immutable whirl, Thou dost behold lives enclosed in time and again led back and returned to the upper spheres — so that the vitality, exhausted by births, which the universe has lost may return to it and may again circulate through the (celestial) bodies.”
An Ancient Chinese Mystery Cult
Authors: Dubs Homer H.
Published: August 2011

Ancient China of the first century B.C., like ancient Greece, possessed more than one religion. There was the national state religion, worshipping the Supreme One (Tai-yi—, also called Heaven [Tien] and the Lord on High [Shang-di]), the Five Lords on High (Wu-di or Wu-shang-di), the imperial ancestors, and other divinities, whose sacrifices were supported by the imperial government. For the educated, there were two philosophical religions, Confucianism and Daoism. For the common people, there were gods, spirits, and ghosts of various sorts, whose care was attended to by such professionals as shamans (mostly female), fortune-tellers, physiognomists, mediums, and exorcists. Such animistic cults were despised by the more intelligent Confucians, who considered them as mere superstition. The famous Confucian, Sün-dz (ca. 320–ca. 235 B.C.), had indeed denied the existence of all spirits.
The effect of temperature on brood duration in three Halicarcinus species (Crustacea: Brachyura: Hymenosomatidae)
Authors: van den Brink Anneke M. , McLay Colin. L. , Hosie Andrew M. , Dunnington Michael J.
Published: August 2011

The effect of temperature on brood development was investigated for three intertidal hymenosomatid crabs: Halicarcinus cookii, H. varius and H. innominatus in Kaikoura, New Zealand. The duration of brood incubation decreased as temperature increased, as did the interbrood period. The duration of each stage of brood development also decreased with increased temperature, but the proportion of total incubation time for each stage remained relatively similar at different temperatures. Hymenosomatid crabs have determinate growth, but moult to maturity at different sizes, thereafter devoting most of their energy to reproduction. The number of broods a female could carry in her lifetime was estimated for each species. Halicarcinus cookii was estimated to be able to produce eight complete broods of 1146 eggs per lifetime, H. varius was estimated to be able to produce seven complete broods of 1051 eggs per lifetime and H. innominatus was estimated to be able to produce six complete broods of 1081 eggs per life time. With the predicted global temperature rise of 2°C in the next 50 years, the authors estimate that, for all three species, a female could produce one extra brood per lifetime (a 10–15% increase in fecundity depending on species), even more if crabs reach maturity faster, potentially leading to a significant population increase.
An investigation on ovarian development of grooved shrimpMelicertus kerathurusin Izmir Bay, Turkey
Authors: Kücükdermenci Aysun , Lok Aynur
Published: August 2011

In the current study, commercially valuable penaeid shrimp,Melicertus kerathurus, were attained approximately monthly in the Izmir Bay, southern Aegean Sea from May 2004 to April 2005. For each specimen, we measured body length, body weight and ovarian weight, and calculated gonadosomatic indices (GSI). GSI values results pointed out that the GSI inMelicertus kerathurusincreased during vitellogenesis (2.03 ± 0.24%) but sharply decreased after spawning (0.53 ± 0.35%) to reach levels similar to those in immature females. We also examined oogenesis inMelicertus kerathurusby histological observation of the ovary to determine reproductive cycle for future domestication. The observation on the gonads leads us to conclude that there are five stages of development for the females: (I) previtellogenic; (II) early vitellogenic; (III) late vitellogenic; (IV) mature; and (V) spent. Histological characteristics showed that the best time to capture adult shrimps for breeding purposes was between the months of April and June. The numbers of each oocyte type that were present were also counted, measured, and used to evaluate the following traits: total oocyte number; mean oocytes diameter; and maximum oocyte diameter. Oocyte diameter was significantly different at all stages (P < 0.05) and the largest diameter was observed as 163.92 ± 4.51µm at stage IV.
Three new species ofKruppomenia(Solenogastres: Simrothiellidae) from the abyssal Angola Basin
Authors: Gil-Mansilla E. , García-Álvarez O. , Urgorri V.
Published: August 2011

During the expedition ‘Me48/1 DIVA 1’, carried out in the abyssal Angola Basin between 5125 and 5415 m depth, several specimens of Solenogastres were collected. Their study has made it possible to describe three new species of the genusKruppomenia(K. angolensissp. nov.,K. glandulatasp. nov. andK. macrodenticulatasp. nov.) with very significant differences in their radular apparatus, reproductive system and pallial cavity. The absence of radular sacs inK. glandulatasp. nov. modifies the genus definition.
Insecure attachment and frequent attendance in primary care: a longitudinal cohort study of medically unexplained symptom presentations in ten UK general practices
Authors: Taylor R. E. , Marshall T. , Mann A. , Goldberg D. P.
Published: August 2011

Background

In primary care frequent attenders with medically unexplained symptoms (MUS) pose a clinical and health resource challenge. We sought to understand these presentations in terms of the doctor–patient relationship, specifically to test the hypothesis that such patients have insecure emotional attachment.

Method

We undertook a cohort follow-up study of 410 patients with MUS. Baseline questionnaires assessed adult attachment style, psychological distress, beliefs about the symptom, non-specific somatic symptoms, and physical function. A telephone interview following consultation assessed health worry, general practitioner (GP) management and satisfaction with consultation. The main outcome was annual GP consultation rate.

Results

Of consecutive attenders, 18% had an MUS. This group had a high mean consultation frequency of 5.24 [95% confidence interval (CI) 4.79–5.69] over the follow-up year. The prevalence of insecure attachment was 28 (95% CI 23–33) %. A significant association was found between insecure attachment style and frequent attendance, even after adjustment for sociodemographic characteristics, presence of chronic physical illness and baseline physical function [odds ratio (OR) 1.96 (95% CI 1.05–3.67)]. The association was particularly strong in those patients who believed that there was a physical cause for their initial MUS [OR 9.52 (95% CI 2.67–33.93)]. A possible model for the relationship between attachment style and frequent attendance is presented.

Conclusions

Patients with MUS who attend frequently have insecure adult attachment styles, and their high consultation rate may therefore be conceptualized as pathological care-seeking behaviour linked to their insecure attachment. Understanding frequent attendance as pathological help seeking driven by difficulties in relating to caregiving figures may help doctors to manage their frequently attending patients in a different way.
The Three-Dimensional Point Spread Function of Aberration-Corrected Scanning Transmission Electron Microscopy
Authors: Lupini Andrew R. , de Jonge Niels
Published: August 2011

Aberration correction reduces the depth of field in scanning transmission electron microscopy (STEM) and thus allows three-dimensional (3D) imaging by depth sectioning. This imaging mode offers the potential for sub-Ångstrom lateral resolution and nanometer-scale depth sensitivity. For biological samples, which may be many microns across and where high lateral resolution may not always be needed, optimizing the depth resolution even at the expense of lateral resolution may be desired, aiming to image through thick specimens. Although there has been extensive work examining and optimizing the probe formation in two dimensions, there is less known about the probe shape along the optical axis. Here the probe shape is examined in three dimensions in an attempt to better understand the depth resolution in this mode. Examples are presented of how aberrations change the probe shape in three dimensions, and it is found that off-axial aberrations may need to be considered for focal series of large areas. It is shown that oversized or annular apertures theoretically improve the vertical resolution for 3D imaging of nanoparticles. When imaging nanoparticles of several nanometer size, regular STEM can thereby be optimized such that the vertical full-width at half-maximum approaches that of the aberration-corrected STEM with a standard aperture.
A 200-kV STEM/SEM Produces 1 Å SEM Resolution
Authors: Zhang Xiao Feng
Published: August 2011

“Second best no more” was the title of an article written by David C. Joy for Nature Materials. The article was for highlighting a breakthrough made by a team formed between Brookhaven National Laboratory (BNL, USA) and Hitachi High Technologies Corporation (HHT, Japan). Sub-angstrom secondary electron (SE) images were obtained on a Hitachi HD-2700, which is a combined scanning electron microscope (SEM) and scanning transmission electron microscope (STEM) operating at a maximum accelerating voltage of 200 kV. For the first time, single atoms and atomic lattices on crystal surfaces are unambiguously presented in SE images.
Simplifying Electron Diffraction Pattern Identification of Mixed-Material Nanoparticles
Authors: Samson Jacopo , Nahirney Patrick C. , Drain Charles Michael , Piscopo Irene
Published: August 2011

Metallic and non-metallic nanoparticles (NPs), ranging in size from 1–200 nm, have unique functional properties that differ from their bulk materials and their component atoms or molecules. These unique properties have driven the demand for nano-sized materials and new methods to synthesize NPs, which are used in drug delivery systems, bio-imaging agents, catalysts, photonics, and optical devices. Inorganic NPs can be synthesized with a variety of methods that impart size, shape, and other structural properties. Cobalt-based NPs, for instance, display unique size and shape-dependent magnetic properties, while the band gap, UV blocking properties and stability of zinc oxide (ZnO) NPs enable new applications in products ranging from cosmetics to solar cell power.
Salutogenic Perspectives on Health Maintenance
Authors: Wiesmann Ulrich , Hannich Hans-Joachim
Published: August 2011

In this article we explore the impact of resistance resources and the sense of meaningfulness – the central component of the sense of coherence (SOC) – on retaining a health maintenance orientation. In this cross-sectional study, 170 rather healthy individuals of a mean age of 67 years filled out a questionnaire assessing resources (self-esteem, self-efficacy, physical health), SOC components (comprehensibility, manageability, and meaningfulness), and multiple health behaviors. Holding resources constant, the SOC components significantly accounted for additional variance in multiple health behaviors. Meaningfulness as the strongest predictor mediated the influence of both self-esteem and self-efficacy on multiple health behaviors. Feeling that one’s life is meaningful helps an older individual to take responsibility for his or her health and to practice multiple healthful behaviors.
Within-Subject Comparison of [11C]-( + )-PHNO and [11C]raclopride Sensitivity to Acute Amphetamine Challenge in Healthy Humans
Authors: Shotbolt Paul , Tziortzi Andri C , Searle Graham E , Colasanti Alessandro , van der Aart Jasper , Abanades Sergio , Plisson Christophe , Miller Sam R , Huiban Mickael , Beaver John D , Gunn Roger N , Laruelle Marc , Rabiner Eugenii A
Published: August 2011

[11C]PHNO is a D2/D3 agonist positron emission tomography radiotracer, with higher in vivo affinity for D3 than for D2 receptors. As [11C]-( + )-PHNO is an agonist, its in vivo binding is expected to be more affected by acute fluctuations in synaptic dopamine than that of antagonist radiotracers such as [11C]raclopride. In this study, the authors compared the effects of an oral dose of the dopamine releaser amphetamine (0.3 mg/kg) on in vivo binding of [11C]-( + )-PHNO and [11C]raclopride in healthy subjects, using a within-subjects, counterbalanced, open-label design. In the dorsal striatum, where the density of D3 receptors is negligible and both tracers predominantly bind to D2 receptors, the reduction of [11C]-( + )-PHNO binding potential ( BPND) was 1.5 times larger than that of [11C]raclopride. The gain in sensitivity associated with the agonist [11C]-( + )-PHNO implies that ~65% of D2 receptors are in the high-affinity state in vivo. In extrastriatal regions, where [11C]-( + )-PHNO predominantly binds to D3 receptors, the amphetamine effect on [11C]-( + )-PHNO BPND was even larger, consistent with the higher affinity of dopamine for D3. This study indicates that [11C]- ( + )-PHNO is superior to [11C]raclopride for studying acute fluctuations in synaptic dopamine in the human striatum. [11C]-( + )-PHNO also enables measurement of synaptic dopamine in D3 regions.
Mouse model of Timothy syndrome recapitulates triad of autistic traits
Authors: Bader Patrick L. , Faizi Mehrdad , Kim Leo H. , Owen Scott F. , Tadross Michael R. , Alfa Ronald W. , Bett Glenna C. L. , Tsien Richard W. , Rasmusson Randall L. , Shamloo Mehrdad
Published: August 2011

Autism and autism spectrum disorder (ASD) typically arise from a mixture of environmental influences and multiple genetic alterations. In some rare cases, such as Timothy syndrome (TS), a specific mutation in a single gene can be sufficient to generate autism or ASD in most patients, potentially offering insights into the etiology of autism in general. Both variants of TS (the milder TS1 and the more severe TS2) arise from missense mutations in alternatively spliced exons that cause the same G406R replacement in the Ca
V
1.2 L-type calcium channel. We generated a TS2-like mouse but found that heterozygous (and homozygous) animals were not viable. However, heterozygous TS2 mice that were allowed to keep an inverted neomycin cassette (TS2-neo) survived through adulthood. We attribute the survival to lowering of expression of the G406R L-type channel via transcriptional interference, blunting deleterious effects of mutant L-type channel overactivity, and addressed potential effects of altered gene dosage by studying Ca
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1.2 knockout heterozygotes. Here we present a thorough behavioral phenotyping of the TS2-neo mouse, capitalizing on this unique opportunity to use the TS mutation to model ASD in mice. Along with normal general health, activity, and anxiety level, TS2-neo mice showed markedly restricted, repetitive, and perseverative behavior, altered social behavior, altered ultrasonic vocalization, and enhanced tone-cued and contextual memory following fear conditioning. Our results suggest that when TS mutant channels are expressed at levels low enough to avoid fatality, they are sufficient to cause multiple, distinct behavioral abnormalities, in line with the core aspects of ASD.
Similar Effects of Visual Perception and Imagery on Simple Reaction Time
Authors: Broggin Elena , Savazzi Silvia , Marzi Carlo A.
Published: August 2011

A longstanding issue is whether perception and mental imagery share similar cognitive and neural mechanisms. To cast further light on this problem, we compared the effects of real and mentally generated visual stimuli on simple reaction time (RT). In five experiments, we tested the effects of difference in luminance, contrast, spatial frequency, motion, and orientation. With the intriguing exception of spatial frequency, in all other tasks perception and imagery showed qualitatively similar effects. An increase in luminance, contrast, and visual motion yielded a decrease in RT for both visually presented and imagined stimuli. In contrast, gratings of low spatial frequency were responded to more quickly than those of higher spatial frequency only for visually presented stimuli. Thus, the present study shows that basic dependent variables exert similar effects on visual RT either when retinally presented or when imagined. Of course, this evidence does not necessarily imply analogous mechanisms for perception and imagery, and a note of caution in such respect is suggested by the large difference in RT between the two operations. However, the present results undoubtedly provide support for some overlap between the structural representation of perception and imagery.
Sir Gareth Gwyn Roberts. 16 May 1940 — 6 February 2007
Authors: Hilsum Cyril
Published: August 2011

Sir Gareth Roberts made a stunning impact on the UK science scene, and his influence and reports brought optimism back into the university sector at a time when morale was low. He will be most remembered for his term as Chairman of the Committee of Vice-Chancellors and Principals (CVCP) in 1995, when the UK government announced savage cuts in university funding, and the CVCP responded by a threat to impose a levy on all first-year students. This led to the 1997 Dearing inquiry into higher education, which recommended many of the points made by Roberts, including fees on a loan basis, access for disadvantaged groups, and support for the vital role of university teaching. The Labour government accepted most of the recommendations, and large increases in university funding followed. In 2001 Roberts was asked to review the problem of the growing shortage of people with science, technology, engineering and mathematics skills, and his report,
SET for success
, was specifically commended by the Prime Minister. Additional funds were provided to raise the stipend of research students, to bring forward measures to recruit and retain science and engineering teachers, to modernize school and university science laboratories, and to create a new national centre for science teaching. He was primarily responsible, as Chairman of the Research Careers Initiative, for implementation of the Concordat, which set out clearly for the first time the need for a career structure for research students, and the way forward to achieve this. His prominence in the national scene might easily cause his earlier scientific achievements to be overlooked, although they were most significant. He first concentrated on the physics governing the injection of electrons into insulators and wide-gap semiconductors, and the laws governing their transit. This led to an interest in organic semiconductors, and his was the first publication on an efficient low-voltage organic light-emitting diode (LED). Concerned that evaporation harmed the properties of organic thin films, he improved the design of the Langmuir–Blodgett trough and developed their technique into a reliable method for the preparation and study of organics. He used the trough for research on a variety of materials, and many groups around the world followed his leadership, gaining much knowledge on the optical and electronic properties of organic conductors and insulators.
Running is the neurogenic and neurotrophic stimulus in environmental enrichment
Authors: Kobilo Tali , Liu Qing-Rong , Gandhi Kriti , Mughal Mohammed , Shaham Yavin , van Praag Henriette
Published: August 2011

Environmental enrichment (EE) increases dentate gyrus (DG) neurogenesis and brain-derived neurotrophic factor (BDNF) levels. However, running is considered an element of EE. To dissociate effects of physical activity and enrichment on hippocampal neurogenesis and BDNF levels, young female C57Bl/6 mice were housed under control, running, enrichment, or enrichment plus running conditions, and injected with bromodeoxyuridine. Cell genesis was assessed after 12 d and differentiation was analyzed 1 mo later. In addition, locomotor activity in the open field and hippocampal mature BDNF peptide levels were measured. Open-field adaptation was improved in all groups, compared to controls, but more so with running. New cell proliferation, survival, neuron number, and neurotrophin levels were enhanced only when running was accessible. We conclude that exercise is the critical factor mediating increased BDNF levels and adult hippocampal neurogenesis.
In Situ Hybridization to Somatic Chromosomes in Drosophila
Authors: Dernburg Abby F.
Published: August 2011

INTRODUCTION

In situ hybridization was originally developed as a technique for visualizing and physically mapping specific sequences on Drosophila melanogaster polytene chromosomes. Hybridization techniques can also be used to localize sequences on smaller, diploid chromosomes, such as condensed mitotic chromosomes. Variations of the method also allow the hybridization of probes to chromosomes within intact cells and tissues, rather than to chromosomes isolated from their cellular context and flattened on slides. This article presents methods for hybridizing fluorescent probes to chromosomes in whole-mount Drosophila tissues. These methods allow the investigation of nuclear organization even at stages where chromosomes are decondensed (as in interphase) or, for other reasons, cannot be discriminated in the light microscope. Consequently, they are useful for addressing a variety of cell biological questions. In addition to enhancing our understanding of somatic chromosome organization, this experimental approach has also revealed interactions among meiotic chromosomes in Drosophila females, which spend much of meiosis in a compact ball called the karyosome. Fluorescent in situ hybridization (FISH) methods can also be used to karyotype individual nuclei using chromosome-specific markers. With appropriate fixation conditions, hybridization to chromosomal DNA can be performed in conjunction with immunostaining, allowing the colocalization of cellular or chromosomal proteins.
Single-Cell Electroporation in Xenopus
Authors: Liu Xue Feng , Haas Kurt
Published: August 2011

INTRODUCTION

Single-cell electroporation (SCE) is a versatile technique for delivering electrically charged macromolecules including DNA, RNA, synthetic oligonucleotides, peptides, dyes, and drugs to individual cells within intact tissues. Here, we describe methods for in vivo-targeted electroporation of single tectal neurons within the albino Xenopus laevis tadpole. Focal electroporation is achieved using a pipette electrode filled with a solution of the delivery molecules and with a tip diameter much smaller than the width of the target cell. The small tip allows for localization of an electric field, which restricts pore formation to only the individual cell in direct contact with the tip. Thus, the small tip permits focal delivery of the charged molecules within the pipette into individual cells. Factors affecting the efficiency of SCE, as well as various applications of this technique, are discussed. Particular focus is directed toward combining SCE with in vivo two-photon microscopy for three-dimensional (3D) imaging of neuron growth and cell-autonomous effects of altered protein function.
Effects of seasonal aridity on the ecology and behaviour of invasive cane toads in the Australian wet–dry tropics
Authors: Brown Gregory P. , Kelehear Crystal , Shine Richard
Published: August 2011

1. Measuring the costs imposed by specific environmental challenges is difficult, because organisms adapt in ways that reduce those costs. Invasive species provide an opportunity to quantify environmental impacts before organisms can make adaptive changes.

2. The native range of cane toads (Rhinella marina) lies within the wet neotropics; although part of this range experiences seasonal drought, many of the places recently invaded by this large anuran species are much more arid.

3. Five years’ fieldwork from a seasonally arid site in the Australian wet–dry tropics shows strong seasonal shifts in the toads’ (i) population structure, reflecting seasonality in breeding and recruitment; (ii) adult morphology (secondary sexual characteristics in males); (iii) growth rates; (iv) energy balance; (v) spatial ecology (philopatry, dispersal rates) and (vi) adult mortality rates.

4. Some of these patterns accord with intuition: for example, wet‐season conditions resulted in higher rates of growth, reproduction and movement, better body condition and more pronounced secondary sexual characteristics. However, seasonal patterns for other traits were non‐intuitive: for example, neither hematocrit levels (reflecting hydration state) nor corticosterone levels (reflecting stress) showed significant seasonal variation, and mortality rates were higher in the wet season than the dry season.

5. The toads’ ability to flexibly adjust their behaviour and ecology to local hydric conditions has allowed them to thrive even under climatic conditions that preclude activity, feeding and reproduction for most of the year.