bluuebunny/crossref_metadata_2025 huggingface dataset:
Bias and error in using survey records for ponderosa pine landscape restoration
Authors: Williams Mark A. , Baker William L.
Published: January 2010

Aim Public land survey records are commonly used to reconstruct historical forest structure over large landscapes. Reconstruction studies have been criticized for using absolute measures of forest attributes, such as density and basal area, because of potential selection bias by surveyors and unknown measurement error. Current methods to identify bias are based upon statistical techniques whose assumptions may be violated for survey data. Our goals were to identify and directly estimate common sources of bias and error, and to test the accuracy of statistical methods to identify them.

Location Forests in the western USA: Mogollon Plateau, Arizona; Blue Mountains, Oregon; Front Range, Colorado.

Methods We quantified both selection bias and measurement error for survey data in three ponderosa pine landscapes by directly comparing measurements of bearing trees in survey notes with remeasurements of bearing trees at survey corners (384 corners and 812 trees evaluated).

Results Selection bias was low in all areas and there was little variability among surveyors. Surveyors selected the closest tree to the corner 95% to 98% of the time, and hence bias may have limited impacts on reconstruction studies. Bourdo’s methods were able to successfully detect presence or absence of bias most of the time, but do not measure the rate of bias. Recording and omission errors were common but highly variable among surveyors. Measurements for bearing trees made by surveyors were generally accurate. Most bearings were less than 5° in error and most distances were within 5% of our remeasurements. Many, but not all, surveyors in the western USA probably estimated diameter of bearing trees at stump height (0.3 m). These estimates deviated from reconstructed diameters by a mean absolute error of 7.0 to 10.6 cm.

Main conclusions Direct comparison of survey data at relocated corners is the only method that can determine if bias and error are meaningful. Data from relocated trees show that biased selection of trees is not likely to be an important source of error. Many surveyor errors would have no impact on reconstruction studies, but omission errors have the potential to have a large impact on results. We suggest how to reduce potential errors through data screening.
Inhibitory Effect of Prepro‐Thyrotrophin‐Releasing Hormone (178–199) on Adrenocorticotrophic Hormone Secretion by Human Corticotroph Tumours
Authors: Pecori Giraldi F. , Pesce S. , Maroni P. , Pagliardini L. , Lasio G. , Losa M. , Cavagnini F.
Published: January 2010

Prepro‐thyrotrophin‐releasing hormone (TRH) (178–199), a 22‐amino acid cleavage product of the TRH prohormone, has been postulated to act as an adrenocorticotrophin hormone (ACTH)‐release inhibitor. Indeed, although in vitro evidence indicates that this peptide may inhibit basal and stimulated ACTH secretion in rodent anterior pituitary primary cultures and cell lines, not all studies concur and no study has as yet evaluated the effect of this peptide in Cushing’s disease. The present study aimed to test the effect of preproTRH(178–199) in human tumoural corticotrophs. Twenty‐four human ACTH‐secreting pituitary tumours (13 macroadenomas, 11 microadenomas) were collected during surgery and incubated with 10 or 100 nm preproTRH(178–199). ACTH secretion was assessed after 4 and 24 h of incubation by immunometric assay and expressed relative to levels observed in control, unchallenged wells (= 100%). Parallel experiments were performed in rat anterior pituitary primary cultures. A clear inhibition of ACTH secretion at 4 and 24 h was observed in 12 specimens (for 10 nm ppTRH: 70 ± 4% control at 4 h and 83 ± 5% control at 24 h; for 100 nm ppTRH: 70 ± 4% control at 4 h and 85 ± 5% control at 24 h), whereas a mild and short‐lasting stimulatory effect was observed in three tumours and no changes in ACTH secretion in the remaining nine tumoural specimens. The inhibitory effect of preproTRH(178–199) was more evident in macroadenomas and significantly correlated with sensitivity to dexamethasone inhibition. Significant inhibition of ACTH secretion by preproTRH(178–199) in rat pituitary cultures was observed after 24 h of incubation. The present study conducted in a large series of human corticotroph tumours shows that preproTRH(178–199) inhibits tumoural ACTH secretion in a sizable proportion of specimens, in close relation to the size of the tumour and its sensitivity to glucocorticoid negative feedback. This appears a promising avenue of research and further studies are warranted to explore the full scope of preproTRH(178–199) as a regulator of ACTH secretion.
Pregnancy Decreases Oestrogen Receptor α Expression and Pyknosis, but not Cell Proliferation or Survival, in the Hippocampus
Authors: Pawluski J. L . , Barakauskas V. E. , Galea L . A. M.
Published: January 2010

Motherhood differentially affects learning and memory performance and this effect depends on reproductive experience. In turn, evidence suggests that the effects of oestradiol on learning and memory are mediated through binding to oestrogen receptors in the hippocampus and that this is related to hippocampal neurogenesis. The present study investigated the effect of pregnancy and reproductive experience on ERα expression throughout the hippocampus, as well as cell proliferation, new cell survival and cell death (as measured by pyknotic cells) in the granule cell layer of the hippocampus. Three groups of female Sprague‐Dawley rats were used: virgin, primigravid and multigravid. All rats were injected with 5‐bromo‐2‐deoxyuridine (BrdU; 200 mg/kg) on the afternoon of impregnation and at matched time‐points in virgins. Rats were perfused either during early pregnancy (gestation day 1) or late pregnancy (gestation day 21) after BrdU injection. The results obtained show that, during late pregnancy, females, whether first or second pregnancy, have fewer ERα‐positive cells in the CA3 region of the dorsal hippocampus than virgin females. In addition during early pregnancy, females have significantly fewer pyknotic cells in the granule cell layer than virgin females. There were no other differences between groups in the number of ERα‐positive, BrdU‐positive or pyknotic cells. Future studies will aim to investigate the mechanisms and consequences of the alteration in ERα expression in the hippocampus during late pregnancy, as well as the possible changes in ERβ expression at this time.
Developmental and Steroidogenic Effects on the Gene Expression of RFamide Related Peptides and their Receptor in the Rat Brain and Pituitary Gland
Authors: Quennell J. H. , Rizwan M. Z. , Relf H.‐L. , Anderson G. M.
Published: January 2010

RFamide related peptides (RFRPs) have been extensively implicated in the neuroendocrine control of reproduction. While steroid hormones strongly regulate the closely‐related kisspeptin gene and protein expression, the regulation of RFRPs or their receptor by steroid hormones is almost unknown. The present study aimed to quantify relative levels of RFRP and Kiss1 gene expression and their G protein‐coupled receptors (GPR147 and GPR54, respectively) in various brain areas and the pituitary gland, and to determine the effects of differing levels of oestradiol and pubertal development on levels of these gene products. In Experiment 1, the treatment groups examined were: dioestrus, ovariectomised and ovariectomised with replacement oestradiol to induce a preovulatory‐like luteinising hormone surge. Micropunched brain regions and whole pituitary glands were processed for measurement of RFRP, Kiss1, GPR147 and GPR54 mRNA by quantitative reverse transcriptase‐polymerase chain reaction. As expected, Kiss1 gene expression was low in the rostral periventricular area of the third ventricle of ovariectomised animals, whereas levels were highest in the arcuate nucleus in this situation. No such oestrogenic effects were observed for RFRP gene expression. GPR147 gene expression was highest in the rostral periventricular region of the third ventricle. The levels of GPR147 and GPR54 mRNA were markedly lower in the pituitary gland than in the hypothalamic regions, and RFRP and Kiss1 mRNA were virtually undetectable in the pituitary gland. These data imply that the actions of RFamides are likely to be predominantly central in nature. In Experiment 2, hypothalamic RFRP and GPR147 mRNA levels were measured in male and female rats aged 2, 4, 6 and 8 weeks. In females, RFRP gene expression increased with developmental age, peaking around the time of puberty, whereas in males gene expression increased between 2 and 4 weeks of age. These results suggest a role in the regulation of adult reproduction rather that prepubertal infertility.
Androgen Decreases Dopamine Neurone Survival in Rat Midbrain
Authors: Johnson M. L. , Day A. E. , Ho C. C. , Walker Q. D. , Francis R. , Kuhn C. M.
Published: January 2010

Clinical studies show that men are more likely to develop disorders affecting midbrain dopaminergic pathways, such as drug addiction and Parkinson’s disease (PD). Although a great deal of focus has been given to the role of oestrogen in the maintenance of midbrain dopaminergic pathways, little is known about how testosterone influences these pathways. In the present study, we used stereological analysis of tyrosine hydroxylase‐immunoreactive (TH‐IR) cell bodies to determine how testosterone influences the dopaminergic cell bodies of the substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA). Rats and mice were castrated at postnatal day (PN) 60, and these midbrain cell populations were counted on PN 90. One month after castration, TH‐IR cell number had increased in the SNpc and VTA of rats and mice. Replacement with testosterone or the non‐aromatisable analogue dihydrotestosterone (DHT) in castrated animals reduced TH‐IR cell number in the SNpc and VTA in rats. In mice, the decrease of TH‐IR cell number with testosterone or DHT replacement was observed only in the SNpc. The apparent increase in TH‐IR neurone number after castration is not explained by an increase in TH expression because the number of nondopaminergic cells (TH‐immunonegative, TH‐IN) did not decrease proportionally after castration. TH‐IN cell number did not change after castration or hormone replacement in rat or mouse SNpc or VTA. These findings suggest that testosterone may play a suppressive role in midbrain dopaminergic pathways.
Stimulus‐Specific Neuroendocrine Responses to Osmotic Challenges in Apelin Receptor Knockout Mice
Authors: Roberts E. M. , Pope G. R. , Newson M. J. F. , Landgraf R. , Lolait S. J. , O’Carroll A.‐M.
Published: January 2010

The expression of the novel peptide apelin and its receptor APJ within specific regions of the brain, in particular the magnocellular neurones of the hypothalamus and the circumventricular organs, has implicated the apelinergic system in mechanisms controlling fluid homeostasis. In addition, apelin and APJ are considered to be involved in controlling arginine vasopressin (AVP) secretion into the circulation and release within the hypothalamic‐neurohypophysial system. To clarify the role of APJ during regulation of fluid homeostasis, we compared the effects of osmotic stimulation on the urinary concentrating capacities and central nervous system responses of salt‐loaded (SL) and water‐deprived (WD) female APJ knockout (APJ−/−) mice and wild‐type controls. SL resulted in a significantly increased urine volume in APJ−/− mice compared to wild‐type controls, whereas WD in APJ−/− mice failed to reduce urine volume as seen in wild‐type controls. AVP transcripts in the supraoptic and paraventricular nuclei and plasma AVP concentrations were significantly attenuated in SL APJ−/− mice compared to SL wild‐type, but increased comparably in wild‐type and APJ−/− mice after WD. Analysis of c‐fos mRNA expression in the median preoptic nucleus and subfornical organ in response to either WD or SL showed attenuated expression in APJ−/− compared to wild‐type mice. These findings further implicate the apelinergic system in mechanisms controlling fluid homeostasis, particularly at a neuroendocrine level, and suggest stimulus‐specific involvement in vasopressinergic activity.
Experimental design and taxonomic scope of fragmentation studies on European mammals: current status and future priorities
Authors: MORTELLITI Alessio , AMORI Giovanni , CAPIZZI Dario , RONDININI Carlo , BOITANI Luigi
Published: January 2010

Habitat loss, habitat fragmentation and habitat degradation are the greatest threats to mammals in Europe and the rest of the world. Despite the fact that extensive literature exists, no comprehensive review or synthesis is available to date and this may slow down scientific progress and hamper conservation efforts.

The goal of this study is to understand if and in what direction progress has been made in the study of the effects of habitat loss and fragmentation on the spatial distribution of European terrestrial mammals. Firstly, we carry out a general synthesis which is structured around 11 key points. The aim of this point‐by‐point analysis is to identify trends, knowledge gaps and any significant bias in the available literature, and to highlight strengths and shortfalls of the different approaches which have to date been applied. Secondly, we follow a species‐specific systematic approach: for each species, we synthesise key results.

Our results show how substantial progress has been hampered for several reasons including: a large predominance of small‐scale field studies of short duration, and a generalised lack of control of: (i) confounding variables; (ii) spatial autocorrelation; and (iii) false absences. Also, despite the relatively high number of studies, few were theoretical studies and even fewer were meta‐analyses. The lack of meta‐analyses is likely to be due to the small amount of crucial details included in the publications, such as model parameters or information on the landscape context (such as the amount of residual forest cover).

We synthesise the main results for 14 species. The level of progress is highly variable: for some species, such as the red squirrel Sciurus vulgaris, a series of long‐term, large‐scale process‐oriented studies has allowed an in‐depth understanding of its ecology in fragmented landscapes. On the other hand, with other species such as the bank vole Myodes glareolus, despite a relatively large number of field studies, little progress has been made.
Control of effector export by the Pseudomonas aeruginosa type III secretion proteins PcrG and PcrV
Authors: Lee Pei‐Chung , Stopford Charles M. , Svenson Amanda G. , Rietsch Arne
Published: January 2010

Pseudomonas aeruginosa uses a type III secretion system to inject protein effectors into a targeted host cell. Effector secretion is triggered by host cell contact. How effector secretion is prevented prior to cell contact is not well understood. In all secretion systems studied to date, the needle tip protein is required for controlling effector secretion, but the mechanism by which needle tip proteins control effector secretion is unclear. Here we present data that the P. aeruginosa needle tip protein, PcrV, controls effector secretion by assembling into a functional needle tip complex. PcrV likely does not simply obstruct the secretion channel because the pore‐forming translocator proteins can still be secreted while effector secretion is repressed. This finding suggests that PcrV controls effector secretion by affecting the conformation of the apparatus, shifting it from the default, effector secretion ‘on’ conformation, to the effector secretion ‘off’ conformation. We also present evidence that PcrG, which can bind to PcrV and is also involved in controlling effector export, is cytoplasmic and that the interaction between PcrG and PcrV is not required for effector secretion control by either protein. Taken together, these data allow us to propose a working model for control of effector secretion by PcrG and PcrV.
Comparison of the TBARS Assay and BODIPY C11 Probes for Assessing Lipid Peroxidation in Red Deer Spermatozoa
Authors: Domínguez‐Rebolledo ÁE , Martínez‐Pastor F , Fernández‐Santos MR , Del Olmo E , Bisbal A , Ros‐Santaella JL , Garde JJ
Published: January 2010

Contents

Several methods are used to measure lipid peroxidation (LPO) in spermatozoa. The objective of this study was comparing the thiobarbituric acid reactive species (TBARS) method and the BODIPY 581/591 C11 (B581) and BODIPY 665/676 C11 (B665) fluorescent probes to measure induced peroxidative damage in thawed epididymal spermatozoa from Iberian red deer. Samples from three males were thawed, pooled, diluted in PBS, incubated at room temperature and assessed at 0, 3, 6 and 24 h under different experimental conditions: Control, hydrogen peroxide (H2O2) 0.1 mm or 1 mm, or tert‐butyl hydroperoxide (TBH) 0.1 mm or 1 mm. LPO was assessed by the TBARS assay [malondialdehyde (MDA) detection] and by the fluorescence probes B581 and B665 (microplate fluorimeter and flow cytometry). Increasing MDA levels were only detectable at 1 mm of TBH or H2O2. Both fluorescence probes, measured with fluorometer, detected significant increases of LPO with time in all treatments, except Control. Flow cytometry allowed for higher sensitivity, with both probes showing a significant linear relationship of increasing LPO with time for all oxidizing treatments (p < 0.001). All methods showed a good agreement, except TBARS, and flow cytometry showed the highest repeatability. Our results show that both B581 and B665 might be used for LPO analysis in Iberian red deer epididymal spermatozoa, together with fluorometry or flow cytometry. Yet, the TBARS method offered comparatively limited sensitivity, and further research must determine the source of that limitation.
A Wittgensteinian Solution to the Sorites
Authors: Ben‐Yami Hanoch
Published: January 2010

I develop a solution to the Sorites Paradox, according to which a concatenation of valid arguments need not itself be valid. I specify which chains of valid arguments are those that do not preserve validity: those that pass the vague boundary between cases where the relevant concept applies and cases where that concept does not apply. I also develop various criticisms of this solution and show why they fail; basically, they all involve a petitio at some stage. I criticise the conviction that if every short argument in a long concatenated argument is valid, so is the long argument: it is, I argue, the result of an unjustified generalisation from the case of arguments that do not employ vague concepts (as in mathematics) to arguments that do employ them. My approach is Wittgensteinian in its “leaving everything as it is,” in its claiming that the “beginning” has been searched too far back (see paper's epigraph) and in its claim that the paradox was generated by a misapplication of a partial picture of the behaviour of arguments. I conclude my paper by comparing and contrasting my approach to the few precedents found in the vagueness literature and by answering a few additional objections that were raised there.
‘Ghost’ experiments and the dissection of social learning in humans and animals
Authors: Hopper Lydia M.
Published: January 2010

The focus of this review is the experimental techniques used to identify forms of social learning shown by humans and nonhuman animals. Specifically, the ‘ghost display’ and ‘end‐state’ conditions, which have been used to tease apart imitative and emulative learning are evaluated. In a ghost display, the movements of an apparatus are demonstrated, often through the discrete use of fishing‐line or hidden mechanisms, without a live model acting directly upon the apparatus so that the apparatus appears to be operated as if by a ‘ghostly’ agent. In an end‐state condition, an observing individual is shown the initial state of the test apparatus, the apparatus is then manipulated out‐of‐sight and then represented to the individual in its final state. The aim of the ghost display condition is to determine whether individuals are able to emulate by replicating the movements of an apparatus, or perform a task, without requiring information about the bodily movements required to do so (imitation). The end‐state condition is used to identify goal‐emulation by assessing whether the observer can replicate the steps required to solve the task without having been shown the required body actions or task movements. The responses of individuals tested with either the ghost display and/or end‐state conditions are compared to those of further individuals who have observed a full demonstration by either a human experimenter or a conspecific. The responses of a control group, to whom no information has been provided about the test apparatus or required actions, are also compared and evaluated. The efficacy of these experimental techniques employed with humans, nonhuman primates, dogs, rats and birds are discussed and evaluated. The experiments reviewed herein emphasise the need to provide ghost displays and end‐state conditions in combination, along with full live demonstrations and a no‐information control. Future research directions are proposed.
AN ANCIENT CHINESE BRONZE FRAGMENT RE‐EXAMINED AFTER 50 YEARS: CONTRIBUTIONS FROM MODERN AND TRADITIONAL TECHNIQUES
Authors: YOUNG M. L. , CASADIO F. , MARVIN J. , CHASE W. T. , DUNAND D. C.
Published: January 2010

Modern analytical techniques, such as secondary ion mass spectrometry, inductively coupled plasma optical emission spectroscopy, in‐situ synchrotron X‐ray diffraction and Raman microscopy, alongside scanning electron microscopy with energy‐dispersive X‐ray analysis and powder X‐ray diffraction, were used to investigate bronze fragments from an ancient Chinese bronze vessel (also known as a hu) in the collection of the Art Institute of Chicago. Previous compositional results obtained by R. J. Gettens in 1951, using traditional optical metallography and powder X‐ray diffraction, were compared with the present analysis. The investigation provided a complete description of the composition of the ancient metal alloy and spatially resolved identification of the major and minor corrosion products. Furthermore, the study also provided the opportunity for a better understanding of the possibilities and limitations of the various instrumental techniques available to the analyst for the study of ancient bronzes.
Exploring the challenges of integrated coastal zone management and reflecting on contributions to ‘integration’ from geographical thought
Authors: MCFADDEN LORAINE
Published: January 2010

Integrated coastal zone management (ICZM) is a challenging process, defined by stakeholder engagement and underpinned by knowledge on the integrated behaviour of coastal systems. While significant advancements in ICZM have been made, a range of difficult and important questions about ‘integration’ remain to be explored. This paper discusses opportunities for addressing such challenges of integration through the application of geographical thinking to understanding and managing coastal environments. It focuses on geographical traditions on systems thinking, the process‐based nature of geographic research and geographical contributions to conceptualising place and our relationships to it. Using UK‐based case studies the paper explores integration challenges from three different coastal contexts and management perspectives, examining: adaptation through managed realignment in a local community, integrated flood risk management in London and the Thames Estuary and enhancing the ‘socially just’ nature of coastal management. The case‐study discussion highlights the importance of ‘geographical thought’ to improving the integrative basis of strategies for managing complex coastal environments. This paper argues that ‘thinking geographically’ is one logical vehicle for increasing our understanding of, and providing solutions to, barriers which limit progress towards greater ‘integration’ in coastal management. Geography is dynamic, plural and based on the recognition that reality is contested and as such geographical ideas could add considerably to emerging cross‐disciplinary knowledge on the interactions and interdependencies of behaviours within coastal systems.
Functional interactions between 5‐HT2Aand presynaptic 5‐HT1Areceptor‐based responses in mice genetically deficient in the serotonin 5‐HT transporter (SERT)
Authors: Fox Meredith A , Stein Alison R , French Helen T , Murphy Dennis L
Published: January 2010

Background and purpose: Despite decreased presynaptic 5‐HT1Aand altered 5‐HT2Areceptor function in genetically‐deficient serotonin (5‐HT) transporter (SERT) mice, the 5‐HT1Areceptor antagonist N‐[2‐[4‐(2‐methoxyphenyl)‐1‐piperazinyl]ethyl]‐N‐2‐pyridinylcyclohexanecarboxamide maleate salt (WAY 100635) still induced head twitches in these mice, a well‐established 5‐HT2Areceptor‐mediated response.

Experimental approach: Interactions between 5‐HT1Aand 5‐HT2Areceptors were assessed using the head‐twitch response following 5‐HT1Aand 5‐HT2Areceptor agonists and antagonists in SERT wild‐type (+/+), heterozygous (+/−), and knockout (−/−) mice. The role of brain 5‐HT availability in WAY 100635 induced head twitches was also examined.

Key results: WAY 100635 induced head twitches in a SERT gene‐dose dependent manner, inducing 5‐fold more head twitches in SERT −/− versus SERT +/+ mice. In SERT −/− mice, inhibition of 5‐HT synthesis with p‐chlorophenylalanine (PCPA) markedly depleted tissue 5‐HT in all five brain areas examined and abolished WAY 100635 induced head twitches. Further, the selective 5‐HT reuptake inhibitor fluvoxamine increased WAY 100635 induced head twitches in SERT +/+ and +/− mice. Head twitches following the 5‐HT2Areceptor agonist (+/−)‐2,5‐dimethoxy‐4‐iodophenyl‐2‐aminopropane (DOI) were robust in SERT +/+ and +/− mice but much reduced in SERT −/− mice. DOI‐induced head twitches were decreased by the 5‐HT1Aagonist 8‐hydroxy‐2‐(di‐n‐propylamino)tetralin (8‐OH‐DPAT) in SERT +/+ and +/− mice. All drug‐induced head twitches were blocked by the 5‐HT2Areceptor antagonist a‐Phenyl‐1‐(2‐phenylethyl)‐4‐piperidinemethanol (MDL 11,939).

Conclusions and implications: These data show that indirect activation of 5‐HT2Areceptors via blockade of presynaptic 5‐HT1Areceptors potentiated head‐twitch responses, suggesting functional interactions between these receptors, interactions affected by altered 5‐HT availability. Our findings strongly support the correlation of WAY 100635 induced head twitches with increased 5‐HT availability, induced genetically or pharmacologically.
δ‐Aminolevulinic acid is a substrate for the amino acid transporter SLC36A1 (hPAT1)
Authors: Frølund S , Marquez OC , Larsen M , Brodin B , Nielsen CU
Published: January 2010

Background and purpose: δ‐Aminolevulinic acid (ALA) is used in cancer patients for photodynamic diagnosis or therapy. Oral administration of ALA has been used in patients with prostate and bladder cancer. The present aim was to investigate the mechanism of intestinal absorption of ALA and its transport via the amino acid transporter SLC36A1.

Experimental approach: In vitroinvestigations of ALA affinity for and uptake via SLC36A1 and SLC15A1 were performed in Caco‐2 cell monolayers. Interaction of ALA with SLC15A1 was investigated in MDCK/SLC15A1cells, whereas interactions with SLC36A1 were investigated in COS‐7 cells transiently expressing SLC36A1.

Key results: ALA inhibited SLC36A1‐mediatedl‐[3H]Pro and SLC15A1‐mediated [14C]Gly‐Sar uptake in Caco‐2 cell monolayers with IC50values of 11.3 and 2.1 mM respectively. In SLC36A1‐expressing COS‐7 cells, the uptake of [14C]ALA was saturable with aKmvalue of 6.8 ± 3.0 mM and aVmaxof 96 ± 13 pmol·cm−2·min−1. Uptake of [14C]ALA was pH and concentration dependent, and could be inhibited by glycine, proline and GABA. In a membrane potential assay, translocation of ALA via SLC36A1 was concentration dependent, with aKmvalue of 3.8 ± 1.0 mM. ALA is thus a substrate for SLC36A1. In Caco‐2 cells, apical [14C]ALA uptake was pH dependent, but Na+independent, and completely inhibited by 5‐hydroxy‐l‐tryptophan andl‐4,4′‐biphenylalanyl‐l‐proline.

Conclusions and implications. ALA was a substrate for SLC36A1, and the apical absorption in Caco‐2 cell was only mediated by SLC36A1 and SLC15A1. This advances our understanding of intestinal absorption mechanisms of ALA, as well as its potential for drug interactions.
The Geriatric Floating Interdisciplinary Transition Team
Authors: Arbaje Alicia I. , Maron David D. , Yu Qilu , Wendel V. Inez , Tanner Elizabeth , Boult Chad , Eubank Kathryn J. , Durso Samuel C.
Published: January 2010

Older adults often receive suboptimal care during hospitalizations and transitions to postacute settings. Inpatient geriatric services have been shown to increase care quality but have not improved patient outcomes consistently. Acute Care for the Elderly units improve patient outcomes but are resource intensive. Transitional care has been shown to reduce hospital readmissions and healthcare costs. This article describes the Geriatric Floating Interdisciplinary Transition Team (Geri‐FITT), a model that combines the strengths of inpatient geriatric evaluation and comanagement and transitional care models by creating an inpatient comanagement service that also delivers transitional care. The Geri‐FITT model is designed to improve the hospital care of older adults and their transitions to postacute settings. In Geri‐FITT, a geriatrician–geriatric nurse practitioner team assesses patients, comanages geriatric syndromes, provides staff education, encourages patient self‐management, communicates with primary care providers, and follows up with patients soon after discharge.

This pilot cohort study of Geri‐FITT included hospitalized patients aged 70 and older on four general medicine services (two Geri‐FITT, two usual care) at an academic medical center (N=717). The study assessed the effect of Geri‐FITT on patients' care transition quality (Care Transitions Measure) and their satisfaction with hospital care (four questions). The results indicate that Geri‐FITT is associated with slightly higher, though not statistically significantly so, quality care transitions and greater patient satisfaction with inpatient care.

Geri‐FITT may be a feasible approach to enhancing inpatient management and transitional care for older adults. Further study of its effect on these and other outcomes in other healthcare settings seems warranted.
Nasogastric Aspiration and Lavage in Emergency Department Patients with Hematochezia or Melena Without Hematemesis
Authors: Palamidessi Nicholas , Sinert Richard , Falzon Louise , Zehtabchi Shahriar
Published: January 2010

Objectives:  The utility of nasogastric aspiration and lavage in the emergency management of patients with melena or hematochezia without hematemesis is controversial. This evidence‐based emergency medicine review evaluates the following question: does nasogastric aspiration and lavage in patients with melena or hematochezia and no hematemesis differentiate an upper from lower source of gastrointestinal (GI) bleeding?

Methods:  MEDLINE, EMBASE, the Cochrane Library, and other databases were searched. Studies were selected for inclusion in the review if the authors had performed nasogastric aspiration (with or without lavage) in all patients with hematochezia or melena and performed esophagogastroduodenal endoscopy (EGD) in all patients. Studies were excluded if they enrolled patients with history of esophageal varices or included patients with hematemesis or coffee ground emesis (unless the data for patients without hematemesis or coffee ground emesis could be separated out). The outcome was identifying upper GI hemorrhage (active bleeding or high‐risk lesions potentially responsible for hemorrhage) and the rate of complications associated with the nasogastric tube insertion. Quality of the included studies was assessed using standard criteria for diagnostic accuracy studies.

Results:  Three retrospective studies met our inclusion and exclusion criteria. The prevalence of an upper GI source for patients with melena or hematochezia without hematemesis was 32% to 74%. According to the included studies, the diagnostic performance of the nasogastric aspiration and lavage for predicting upper GI bleeding is poor. The sensitivity of this test ranged from 42% to 84%, the specificity from 54% to 91%, and negative likelihood ratios from 0.62 to 0.20. Only one study reported the rate complications associated with nasogastric aspiration and lavage (1.6%).

Conclusions:  Nasogastric aspiration, with or without lavage, has a low sensitivity and poor negative likelihood ratio, which limits its utility in ruling out an upper GI source of bleeding in patients with melena or hematochezia without hematemesis.

ACADEMIC EMERGENCY MEDICINE 2010; 17:126–132 © 2010 by the Society for Academic Emergency Medicine
Markers of Overcrowding in a Pediatric Emergency Department
Authors: Stang Antonia S. , McGillivray David , Bhatt Maala , Colacone Antoinette , Soucy Nathalie , Léger Ruth , Afilalo Marc
Published: January 2010

Objectives:  The objective of this study was to identify markers of overcrowding in pediatric emergency departments (PEDs) according to expert opinion and then to use statistical methods to further explore the underlying construct of overcrowding.

Methods:  A cross‐sectional survey of all PED directors (n = 12) and pediatric emergency medicine fellowship program directors (n = 10) across Canada was conducted to elicit expert opinion on relevant markers of emergency department (ED) crowding. The list of markers was reduced to those specific to the ED for which data could be extracted from one tertiary care PED from an existing computerized patient tracking system. Data representing 2,190 consecutive shifts and 138,361 patient visits were collected between April 2005 and March 2007. Common factor analysis (CFA) was used to determine the underlying factors that best represented overcrowding as determined by markers identified by experts in pediatric emergency medicine

Results:  The main markers of overcrowding identified by the survey included measures of patient volume (25%), ED operational processes (55%), and delays in transferring patients to inpatient beds (13%). Data collected on 41 markers were retained for the CFA. The results of the CFA indicated that the largest portion of variation in the data (48%) was accounted for by markers describing patient volumes and flow through the ED. Measures of admission delays accounted for a smaller proportion of variability (9%).

Conclusions:  The results suggest that for this tertiary PED, markers of ED operational processes and patient volume may be more relevant for determination of overcrowding than markers reflecting delays in transferring patients to inpatient beds. This study provides a foundation for further research on markers of overcrowding specific to the pediatric setting.

ACADEMIC EMERGENCY MEDICINE 2010; 17:151–156 © 2010 by the Society for Academic Emergency Medicine
Earlier versus later continuous Kangaroo Mother Care (KMC) for stable low‐birth‐weight infants: a randomized controlled trial
Authors: Nagai S , Andrianarimanana D , Rabesandratana N , Yonemoto N , Nakayama T , Mori R
Published: January 2010

Aim:  The aim of this study was to examine the effectiveness of earlier continuous Kangaroo Mother Care (KMC) for relatively stable low‐birth‐weight (LBW) infants in a resource‐limited country.

Methods:  A randomized controlled trial was performed in LBW infants at a referral hospital in Madagascar. Earlier continuous KMC (intervention) was begun as soon as possible, within 24 h postbirth, and later continuous KMC (control: conventional care) was begun after complete stabilization (generally after 24 h postbirth). Main outcome measure was mortality during the first 28 days postbirth. This trial was registered with ClinicalTrials.gov, NCT00531492.

Results:  A total of 73 infants (intervention 37, control 36) were included. Earlier continuous KMC had higher but no statistically different mortality in the first 28 days postbirth (1 vs. 2; risk ratio, 1.95; 95% CIs, 0.18–20.53; p = 1.00). There were no differences in incidence of morbidities. Body weight loss from birth to 24 h postbirth was significantly less in earlier KMC infants compared with later KMC infants. (−34.81 g vs. −73.97 g; mean difference, 39.16 g; 95% CIs, 10.30–68.03; p = 0.01; adjusted p = 0.02). Adverse events and duration of hospitalization were not different between the two groups.

Conclusions:  Further evaluations of earlier continuous KMC including measurement of KMC dose, are needed in resource‐limited countries.
Esthetic Considerations in Interdental Papilla: Remediation and Regeneration
Authors: SHARMA ANITA ANGELA , PARK JAE HYUN
Published: January 2010

This article reviews the etiology and treatment of open gingival embrasures or black triangles. An open gingival embrasure or black triangle occurs as a result of a deficiency of papilla beneath the contact point. The treatment of open embrasures may require restorative, orthodontic and periodontal considerations depending on the underlying etiology. The authors reviewed a total of 42 articles including review of literature, radiographic, cross‐sectional, and retrospective studies in Ovid search engine using the terms “open gingival embrasure,”“interdental papilla,” and “black triangle.” The studies provided information regarding etiology, diagnosis, and treatment of open embrasures. There are several risk factors leading to the development of open gingival embrasures. These factors include aging, periodontal disease, loss of height of the alveolar bone relative to the interproximal contact, length of embrasure area, root angulations, interproximal contact position, and triangular‐shaped crowns. Treatment of open embrasures requires an interdisciplinary approach of orthodontic, periodontic, and restorative treatment.

CLINICAL SIGNIFICANCE

Open gingival embrasures are complex esthetic and functional problems. An interdisciplinary team approach with the general dentist, orthodontist, and periodontist is critical. Management of open embrasures requires careful evaluation of the underlying etiology.

(J Esthet Restor Dent 22:18–30, 2010)
Correlation between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro
Authors: GHANAME EDUARDO S. , RITTER ANDRÉ V. , HEYMANN HARALD O. , VANN, Jr. WILLIAM F. , SHUGARS DANIEL A. , BADER JAMES D.
Published: January 2010

Objective:  This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro.

Materials and Methods:  One hundred and three permanent molars and premolars containing incipient occlusal pit‐and‐fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically.

Results:  The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low (r = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively.

Conclusions:  Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries.

CLINICAL SIGNIFICANCE

Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.

(J Esthet Restor Dent 22:31–41, 2010)
Spectrophotometric Analysis of Tooth Color Reproduction on Anterior All‐Ceramic Crowns: Part 1: Analysis and Interpretation of Tooth Color
Authors: ISHIKAWA‐NAGAI SHIGEMI , YOSHIDA AKI , DA SILVA JOHN D. , MILLER LLOYD
Published: January 2010

Color matching of a natural maxillary central incisor is one of the most difficult challenges in clinical dentistry. Accurate color determination and interpretation of tooth color information in ceramic work is an important step in achieving success in ideal color reproduction. In this case study, factors that influence tooth color determination were analyzed, and the process of interpretation of tooth color information was assessed based on scientific color data using a novel dental spectrophotometer system.

An all‐ceramic crown for a maxillary right central incisor was the subject of this color assessment. The contralateral incisor was an intact natural tooth that was bleached and then used as the target shade for an all‐ceramic crown. The dental spectrophotometer (Crystaleye, Olympus, Tokyo, Japan) was used for tooth color measurement and analysis. The target tooth, prepared tooth, maxillary arch, and face images were captured for color information. Tooth color stabilization related to tooth bleaching and tooth dehydration was assessed. Based on tooth color data obtained by the dental spectrophotometer, color was analyzed in several different areas of a tooth using CIELAB (Commission Internationale de l'Eclarirage) color coordinates L*, a*, b*, and color difference ΔE. Interpretation of the tooth color information was made in each of porcelain layers on a blue map, and its intensions for color reproduction were described.

Throughout this spectrophotometric assessment, the process of stabilized tooth color determination, tooth color analysis, interpretations, and fabrication of a blue map for porcelain work was clarified with color data as scientific evidence.

CLINICAL SIGNIFICANCE

The use of a dedicated dental spectrophotometer allows the evaluation and measurement of the color of a bleached tooth. This allows the laboratory technician to more precisely understand the bleached tooth shade as well as when the bleached tooth color has become stable enough to match to a contralateral all‐ceramic crown restoration.

(J Esthet Restor Dent 22:42–52, 2010)
Spectrophotometric Analysis of Tooth Color Reproduction on Anterior All‐Ceramic Crowns: Part 2: Color Reproduction and Its Transfer from In Vitro to In Vivo
Authors: YOSHIDA AKI , MILLER LLOYD , DA SILVA JOHN D. , ISHIKAWA‐NAGAI SHIGEMI
Published: January 2010

Color reproduction of an anterior tooth requires advanced laboratory techniques, talent, and artistic skills. Color matching in a laboratory requires the successful transfer from in vivo with careful considerations. The purpose of this study was to monitor and verify the color reproduction process for an anterior all‐ceramic crown in a laboratory through spectrophotometric measurements. Furthermore, a crown insertion process using composite luting cements was assessed, and the final color match was measured and confirmed.

An all‐ceramic crown with a zirconia ceramic coping for the maxillary right central incisor was fabricated. There was a significant color difference between the prepared tooth and the die material. The die material selected was the closest match available. The ceramic coping filled with die material indicated a large color difference from the target tooth in both lightness and chromaticity. During the first bake, three different approaches were intentionally used corresponding with three different tooth regions (cervical, body, and incisal). The first bake created the fundamental color of the crown that allowed some color shifts in the enamel layer, which was added later. The color of the completed crown demonstrated an excellent color match, with ΔE 1.27 in the incisal and 1.71 in the body. In the cervical area, color match with ΔE 2.37 was fabricated with the expectation of a color effect from the underlying prepared tooth. The optimal use of composite luting cement adjusted the effect from the underlying prepared tooth color, and the color match fabricated at a laboratory was successfully transferred to the clinical setting. The precise color measurement system leads to an accurate verification of color reproduction and its transfer.

CLINICAL SIGNIFICANCE

The use of a dedicated dental spectrophotometer during the fabrication of an all‐ceramic crown allows the dentist and the laboratory technician to accurately communicate important information to one another about the shade of the tooth preparation, the shade of the contralateral target tooth, and the influence of luting cement on the final restoration, thereby allowing the technician better control over the outcome of their tooth color matching efforts and the final color match of an all‐ceramic restoration.

(J Esthet Restor Dent 22:53–65, 2010)
Predictors of breastfeeding cessation among HIV‐infected women in Dar es Salaam, Tanzania
Authors: Petraro Paul , Duggan Christopher , Msamanga Gernard , Peterson Karen E. , Spiegelman Donna , Fawzi Wafaie
Published: January 2010

This paper examines predictors of breastfeeding cessation among a cohort of human immunodeficiency virus (HIV)‐infected women. This was a prospective follow‐up study of HIV‐infected women who participated in a randomized micronutrient supplementation trial conducted in Dar es Salaam, Tanzania. 795 HIV‐infected Tanzanian women with singleton newborns were utilized from the cohort for this analysis. The proportion of women breastfeeding declined from 95% at 12 months to 11% at 24 months. The multivariate analysis showed breastfeeding cessation was significantly associated with increasing calendar year of delivery from 1995 to 1997 [risk ratio (RR), 1.36; 95% confidence interval (CI) 1.13–1.63], having a new pregnancy (RR 1.33; 95% CI 1.10–1.61), overweight [body mass index (BMI) ≥25 kg m−2; RR 1.37; 95% CI 1.07–1.75], underweight (BMI <18.5 kg m−2; RR 1.29; 95% CI 1.00–1.65), introduction of cow's milk at infant's age of 4 months (RR 1.30; 95% CI 1.04–1.63). Material and social support was associated with decreased likelihood of cessation (RR 0.83; 95% CI 0.68–1.02). Demographic, health and nutritional factors among women and infants are associated with decisions by HIV‐infected women to cease breastfeeding. The impact of breastfeeding counselling programs for HIV‐infected African women should consider individual maternal, social and health contexts.
Role of the plasma membrane leaflets in drug uptake and multidrug resistance
Authors: Katzir Hagar , Yeheskely‐Hayon Daniella , Regev Ronit , Eytan Gera D.
Published: January 2010

The present study aimed to investigate the role played by the leaflets of the plasma membrane in the uptake of drugs into cells and in their extrusion by P‐glycoprotein and multidrug resistance‐associated protein 1. Drug accumulation was monitored by fluorescence resonance energy transfer from trimethylammonium‐diphenyl‐hexatriene (TMA‐DPH) located at the outer leaflet to a rhodamine analog. Uptake of dye into cells whose mitochondria had been inactivated was displayed as two phases of TMA‐DPH fluorescence quenching. The initial phase comprised a rapid drop in fluorescence that was neither affected by cooling the cells on ice, nor by activity of mitochondria or ABC transporters. This phase reflects the association of dye with the outer leaflet of the plasma membrane. The subsequent phase of TMA‐DPH fluorescence quenching occurred in drug‐sensitive cell lines with a half‐life in the range 20–40 s. The second phase of fluorescence quenching was abolished by incubation of the cells on ice and was transiently inhibited in cells with active mitochondria. Thus, the second phase of fluorescence quenching reflects the accumulation of dye in the cytoplasmic leaflet of the plasma membrane, presumably as a result of flip‐flop of dye across the plasma membrane and slow diffusion from the inner leaflet into the cells. Whereas activity of P‐glycoprotein prevented the second phase of fluorescence quenching, the activity of multidrug resistance‐associated protein 1 had no effect on this phase. Thus, P‐glycoprotein appears to pump rhodamines from the cytoplasmic leaflet either to the outer leaflet or to the outer medium.