bluuebunny/crossref_metadata_2025 huggingface dataset:
Arabidopsis 3-Ketoacyl-Coenzyme A Synthase9 Is Involved in the Synthesis of Tetracosanoic Acids as Precursors of Cuticular Waxes, Suberins, Sphingolipids, and Phospholipids
Authors: Kim Juyoung , Jung Jin Hee , Lee Saet Buyl , Go Young Sam , Kim Hae Jin , Cahoon Rebecca , Markham Jennifer E. , Cahoon Edgar B. , Suh Mi Chung
Published: April 2013

Very-long-chain fatty acids (VLCFAs) with chain lengths from 20 to 34 carbons are involved in diverse biological functions such as membrane constituents, a surface barrier, and seed storage compounds. The first step in VLCFA biosynthesis is the condensation of two carbons to an acyl-coenzyme A, which is catalyzed by 3-ketoacyl-coenzyme A synthase (KCS). In this study, amino acid sequence homology and the messenger RNA expression patterns of 21 Arabidopsis (Arabidopsis thaliana) KCSs were compared. The in planta role of the KCS9 gene, showing higher expression in stem epidermal peels than in stems, was further investigated. The KCS9 gene was ubiquitously expressed in various organs and tissues, including roots, leaves, and stems, including epidermis, silique walls, sepals, the upper portion of the styles, and seed coats, but not in developing embryos. The fluorescent signals of the KCS9::enhanced yellow fluorescent protein construct were merged with those of BrFAD2::monomeric red fluorescent protein, which is an endoplasmic reticulum marker in tobacco (Nicotiana benthamiana) epidermal cells. The kcs9 knockout mutants exhibited a significant reduction in C24 VLCFAs but an accumulation of C20 and C22 VLCFAs in the analysis of membrane and surface lipids. The mutant phenotypes were rescued by the expression of KCS9 under the control of the cauliflower mosaic virus 35S promoter. Taken together, these data demonstrate that KCS9 is involved in the elongation of C22 to C24 fatty acids, which are essential precursors for the biosynthesis of cuticular waxes, aliphatic suberins, and membrane lipids, including sphingolipids and phospholipids. Finally, possible roles of unidentified KCSs are discussed by combining genetic study results and gene expression data from multiple Arabidopsis KCSs.
Dynamic Transcriptomic Profiles between Tomato and a Wild Relative Reflect Distinct Developmental Architectures
Authors: Chitwood Daniel H. , Maloof Julin N. , Sinha Neelima R.
Published: April 2013

Developmental differences between species commonly result from changes in the tissue-specific expression of genes. Clustering algorithms are a powerful means to detect coexpression across tissues in single species but are not often applied to multidimensional data sets, such as gene expression across tissues in multiple species. As next-generation sequencing approaches enable interspecific analyses, methods to visualize and explore such data sets will be required. Here, we analyze a data set comprising gene expression profiles across six different tissue types in domesticated tomato (Solanum lycopersicum) and a wild relative (Solanum pennellii). We find that self-organizing maps are a useful means to analyze interspecies data, as orthologs can be assigned to independent levels of a “super self-organizing map.” We compare various clustering approaches using a principal component analysis in which the expression of orthologous pairs is indicated by two points. We leverage the expression profile differences between orthologs to look at tissue-specific changes in gene expression between species. Clustering based on expression differences between species (rather than absolute expression profiles) yields groups of genes with large tissue-by-species interactions. The changes in expression profiles of genes we observe reflect differences in developmental architecture, such as changes in meristematic activity between S. lycopersicum and S. pennellii. Together, our results offer a suite of data-exploration methods that will be important to visualize and make biological sense of next-generation sequencing experiments designed explicitly to discover tissue-by-species interactions in gene expression data.
ACYL-LIPID DESATURASE2Is Required for Chilling and Freezing Tolerance inArabidopsis
Authors: Chen Mingjie , Thelen Jay J.
Published: April 2013

Fatty acid desaturation of membrane lipids is a strategy for plants to survive chilling or freezing temperature. To further characterize enzymes involved in this stress response pathway, ACYL-LIPID DESATURASE2 (ADS2; Enzyme Commission 1.14.99) was studied using genetic, cell, and biochemical approaches. ads2 mutant plants appear similar to the wild type under standard growth conditions but display a dwarf and sterile phenotype when grown at 6°C and also show increased sensitivity to freezing temperature. Fatty acid composition analysis demonstrated that ads2 mutant plants at 6°C have reduced levels of 16:1, 16:2, 16:3, and 18:3 and higher levels of 16:0 and 18:0 fatty acids compared with the wild type. Lipid profiling revealed that 34C species of phosphatidylglycerol (PG) and monogalactosyl diacylglycerol (MGDG) content in ads2 mutants were lower and phosphatidic acid, phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine, lyso-phosphatidylcholine, and phosphatidylserine were higher than the wild type. Subcellular localization of C- and N-terminal enhanced fluorescence fusion proteins indicated that ADS2 localized primarily to the endoplasmic reticulum, although signal was also confirmed in Golgi and plastids. A double mutation with a putative plastid ADS3 paralog exacerbates the growth defects of ads2 mutant plants under low temperature. These observations suggest that ADS2 encodes a 16:0 desaturase of MGDG and PG. We hypothesize that a low temperature–induced shift from the plastid to endoplasmic reticulum pathway for membrane lipid biosynthesis is required for the cold stress response in Arabidopsis thaliana, and ADS2 is essential to adjust the acyl composition of organelle membrane lipid composition in response to cold stress.
Herbivory differentially alters litter dynamics of two functionally contrasted grasses
Authors: Ibanez Sébastien , Bernard Lionel , Coq Sylvain , Moretti Marco , Lavorel Sandra , Gallet Christiane
Published: April 2013

Herbivores can have contrasted impacts on litter quality and litter decomposition, through an alteration of leaf chemistry and leaf senescence. Depending on the context, herbivores can induce defensive secondary compounds and thus slow down litter decomposition or accelerate decomposition by short‐cutting nutrient resorption.

Almost nothing is known for grasses, which contain smaller amounts of secondary compounds than forbs and trees. Because grasses span a gradient from exploitative species having a low C : N ratio and induced defences, to conservative species having a high C : N ratio and constitutive defences, we hypothesize that the litter dynamics of functionally contrasted grasses may be differentially altered by herbivores.

In a mesocosm experiment, we assessed the litter decomposition rate of two subalpine grasses, the more exploitative Dactylis glomerata and the conservative Festuca paniculata, in the presence of two grasshopper species, Chorthippus scalaris and Euthystira brachyptera. We hypothesized that decomposition patterns depending on grass species and herbivory could be explained by the C : N ratio and the total phenolic content of fresh, senescent and decomposed leaves.

Herbivory by grasshoppers induced the accumulation of phenolics in the fresh leaves of D. glomerata, but most of these compounds were lost during senescence. The decomposition rate of D. glomerata senescent leaves did not depend on herbivory, phenolics and N content or C : N ratio. In contrast, herbivory did not induce any phenolic accumulation in the grazed leaves of F. paniculata, but during senescence, phenolics disappeared in greater proportions in grazed leaves than in ungrazed leaves, probably due to the physical alteration of grazed leaves. Herbivory slowed down the decomposition rate of F. paniculata, which was correlated to the phenolic concentration of senescent leaves, but not to the C : N ratio or N content.

Herbivory by grasshoppers differentially altered the litter decomposition rate of the two functionally contrasted grasses, having no effect on D. glomerata and slowing down F. paniculata. Thus, the combination of chemical and physical modifications of leaves by grazing and their interaction with grass traits may have either accelerating or decelerating effects on litter decomposition, with potentially complex outcomes at the ecosystem level.
Inadvertent consequences of fishing: the case of the sex‐changing shrimp
Authors: Côté Isabelle M.
Published: April 2013

The Hokkai shrimp Pandalus latirostris starts life as a male, but eventually turns into a female given the right size and social conditions. The traps used in the fishery targeting this species selectively retain the larger females, leaving a severely male‐biased sex ratio in nature and social conditions that bear no resemblance to those that prompted (or prevented) sex change. Photo: Susumu Chiba

image

The Hokkai shrimp Pandalus latirostris starts life as a male, but eventually turns into a female given the right size and social conditions. The traps used in the fishery targeting this species selectively retain the larger females, leaving a severely male‐biased sex ratio in nature and social conditions that bear no resemblance to those that prompted (or prevented) sex change. Photo: Susumu Chiba

Chiba, S., Yoshino, K., Kanaiwa, M., Kawajiri, T. & Goshima, S. (2013) . Journal of Animal Ecology, 82, 631–640.

Fishing can have many unintended consequences. In this issue, Chiba et al. (2013) demonstrate that size‐selective harvesting of a sex‐changing shrimp effectively voids their normally adaptive adjustments to population sex ratio. The shrimp's ‘decision’ to change sex depends largely on the relative abundance of mature males and females in early summer, before fishing begins. However, fishing traps selectively retain females, leading to heavily male‐biased sex ratios at the onset of autumn breeding that are different from the ratios that influenced sex‐change decisions. Although this phenomenon is not yet expressed in catch trends, maladaptive sex‐change decisions could ultimately affect population productivity and persistence.
Competent in evidence‐based practice (EBP): validation of a measurement tool that measures EBP self‐efficacy and task value in speech–language therapy students
Authors: Spek B. , Wieringa‐de Waard M. , Lucas C. , van Dijk N.
Published: April 2013

Background

Worldwide speech–language therapy (SLT) students are educated in evidence‐based practice (EBP). For students to use EBP in their future day‐to‐day clinical practice, they must value EBP as positive and must feel confident in using it. For curricula developers it is therefore important to know the impact their teaching has on these aspects of students’ motivational beliefs.

Aims

To develop and validate a measurement tool to assess EBP task value and self‐efficacy in SLT students.

Methods & Procedures

A 20‐item questionnaire was developed based on a review of the literature and an additional group interview with speech–language therapists. Face validity of the questionnaire was established using a Delphi panel consisting of six EBP lecturers. Dutch bachelor SLT students (n = 149) with a different level of EBP knowledge and skills filled in the newly developed questionnaire. Reliability (internal consistency) was assessed using Cronbach's alpha and internal validity using a principal component analysis (PCA). Construct validity was assessed by comparing the bachelor SLT student scores with a group of m students (n = 15) who were highly experienced in EBP.

Outcomes & Results

The PCA showed that the questionnaire consists of two components, representing EBP task value and self‐efficacy, both with good reliability (Cronbach's α = 0.83 and 0.79, respectively). The hypothesis that master's students would score significantly higher on both components than bachelor SLT students was met.

Conclusions & Implications

The study provides evidence on the internal consistency and construct validity of this questionnaire to evaluate EBP task value and self‐efficacy in SLT students. As is common with new measures, more research is needed to evaluate further its psychometric properties.
Teaching evidence‐based practice (EBP) to speech–language therapy students: are students competent and confident EBP users?
Authors: Spek B. , Wieringa‐de Waard M. , Lucas C. , van Dijk N.
Published: April 2013

Background

The importance and value of the principles of evidence‐based practice (EBP) in the decision‐making process is recognized by speech–language therapists (SLTs) worldwide and as a result curricula for speech–language therapy students incorporated EBP principles. However, the willingness actually to use EBP principles in their future profession not only depends on EBP knowledge and skills, but also on self‐efficacy and task value students perceive towards EBP.

Aims

To investigate the relation between EBP knowledge and skills, and EBP self‐efficacy and task value in different year groups of Dutch SLT students.

Methods & Procedures

Students from three year groups filled in a tool that measured EBP knowledge and skills: the Dutch Modified Fresno (DMF). EBP self‐efficacy and task value were assessed by using a 20‐item questionnaire. Both tools were validated for this population. Mean scores for the three year groups were calculated and tested for group differences using a one‐way analysis of variance (ANOVA) with a post‐hoc Games–Howell procedure. With a multiple linear regression technique it was assessed whether EBP self‐efficacy and task value predict learning achievement scores on the DMF. Other possible predictors included in the model were: level of prior education, standard of English, having had mathematics in prior education and the SLT study year.

Outcome & Results

A total of 149 students filled in both measurement tools. Mean scores on EBP knowledge and skills were significantly different for the three year groups, with students who were further along their studies scoring higher on the DMF. Mean scores on the EBP self‐efficacy and task value questionnaire were the same for the three year groups: all students valued EBP positive but self‐efficacy was low in all groups. Of the possible predictors, only the year in which students study and EBP self‐efficacy were significant predictors for learning achievements in EBP.

Conclusions & Implications

Despite a significant increase in EBP knowledge and skills over the years as assessed by the DMF, the integrated EBP curriculum did not raise levels of EBP self‐efficacy and task value. This lack of feeling competent might have an impact on students’ willingness actually to use EBP. In curricula, therefore, there should be a focus on how to raise EBP self‐efficacy in SLT students. This goes even beyond the educational department because a professional culture in which professionals are competent and confident EBP users would have a positive effect on EBP self‐efficacy in students.
A practical comparison of manual and autonomous methods for acoustic monitoring
Authors: Digby Andrew , Towsey Michael , Bell Ben D. , Teal Paul D.
Published: April 2013

Autonomous acoustic recorders are widely available and can provide a highly efficient method of species monitoring, especially when coupled with software to automate data processing. However, the adoption of these techniques is restricted by a lack of direct comparisons with existing manual field surveys.

We assessed the performance of autonomous methods by comparing manual and automated examination of acoustic recordings with a field‐listening survey, using commercially available autonomous recorders and custom call detection and classification software. We compared the detection capability, time requirements, areal coverage and weather condition bias of these three methods using an established call monitoring programme for a nocturnal bird, the little spotted kiwi (Apteryx owenii).

The autonomous recorder methods had very high precision (>98%) and required <3% of the time needed for the field survey. They were less sensitive, with visual spectrogram inspection recovering 80% of the total calls detected and automated call detection 40%, although this recall increased with signal strength. The areal coverage of the spectrogram inspection and automatic detection methods were 85% and 42% of the field survey. The methods using autonomous recorders were more adversely affected by wind and did not show a positive association between ground moisture and call rates that was apparent from the field counts. However, all methods produced the same results for the most important conservation information from the survey: the annual change in calling activity.

Autonomous monitoring techniques incur different biases to manual surveys and so can yield different ecological conclusions if sampling is not adjusted accordingly. Nevertheless, the sensitivity, robustness and high accuracy of automated acoustic methods demonstrate that they offer a suitable and extremely efficient alternative to field observer point counts for species monitoring.
Trajectories of depressive symptoms in response to prolonged stress in medical interns
Authors: Guille C. , Clark S. , Amstadter A. B. , Sen S.
Published: April 2013

Objective

The high degree of heterogeneity in the development of depression under stress is unaccounted for in traditional statistical modeling. We employ growth mixture modeling to identify classes of individuals at highest risk of depression under stress.

Method

Medical internship was used as a prospective stress model. Interns from US residency programs completed demographic, psychological, and depressive symptom assessments 2 months prior to internship and at 3‐month intervals throughout internship year.

Results

A total of 2278 (59%) of interns chose to take part in the study. Three classes of depressive symptoms were identified: i) Stress‐resilient class: 62% of participants report low depressive symptoms before and throughout internship year; ii) Stress‐neutral class: 22% of participants report mild depressive symptoms before and throughout internship year; and iii) Stress‐sensitive class: 16% of participants report low depressive symptoms before internship stress, and high levels of depressive symptoms throughout internship year. Individuals in the Stress‐sensitive class were more likely to be female, in a surgical specialty, and have a history of depression, difficulty early family environment and high‐neuroticism scores compared with individuals in the Stress‐resilient class.

Conclusion

Trajectory‐based analysis allows for the identification of a high‐risk group, within a heterogeneous population, that accounts for the link between stress and depression.
The producer welfare effects of trade liberalization when goods are perishable and habit‐forming: the case of asparagus
Authors: Ferrier Peyton , Zhen Chen
Published: April 2013

Asparagus is a perishable, highly seasonal crop. We find that out‐of‐season imports of asparagus caused habit formation that increased demand in the U.S. growing seasons. We find that habit effects offset about 64% of the welfare losses to U.S. asparagus producers from increased Mexican imports under NAFTA and all of the U.S. producer welfare losses from increased Peruvian imports under the Andean Trade Preference Act. We estimate that the U.S. producer welfare losses from NAFTA are less than the annualized value of market loss assistance provided them in the 2008 Farm Bill.
Variation in plant biodiversity across sacred groves and fallows in Western Highlands of Cameroon
Authors: Tankou Christopher M. , de Snoo Geert R. , de Iongh Hans H. , Persoon Gerard
Published: April 2013

The study was conducted to compare species richness and diversity in different ecosystems and abiotic factors. The results showed that the sacred groves had a plant genetic diversity composed of a total of 42, 65 and 82 ethno‐botanical species of herbs, shrubs and trees, respectively, with varied qualities. There were six herbaceous species common in the fallow ecosystem and the sacred groves, 35 herbaceous species found in the sacred grove and absent in the fallow vegetation and 70 herbaceous species in the fallow vegetation and absent in the ground layer of the sacred groves. Thirty‐two regenerated species and 49 nonregenerated tree species were found in the sacred groves. The herbaceous α‐diversity was significantly higher in the fallows than the sacred groves at the low altitude. The tree species richness was higher at the low altitude compared to the high altitude with tree β‐diversity increasing with altitude. Varying combinations of soil pH, total P, total K, CEC and slope per cent were related to some of the parameters evaluated. Biodiversity changes in the sacred groves may be governed by biophysical drivers, while a combination of human and biophysical explained the variation in rotational fallow vegetation.
A survey on knowledge of female genital mutilation guidelines
Authors: Purchase Thomas C.D. , Lamoudi Maya , Colman Sarah , Allen Siobhan , Latthe Pallavi , Jolly Kate
Published: April 2013

The increase in immigration from countries with a high prevalence of female genital mutilation (FGM) has highlighted the need for knowledge and sensitivity in this area of healthcare in high‐resource countries. We have surveyed with an online questionnaire 607 members, fellows and trainees of the Royal College of Obstetricians and Gynaecologists (RCOG) on knowledge about the RCOG guidelines for FGM. Completed training and more practical experience with women affected by FGM significantly increased knowledge. Many respondents were not aware of specialist services locally (22.9%) or how to access them (52.3%). Some areas of insufficient knowledge were identified, in particular in relation to psychiatric morbidity, HIV, hepatitis B and pelvic infection. More specialized training efforts might improve this aspect.
Tobacco smoking, exposure to second‐hand smoke, and asthma and wheezing in schoolchildren: a cross‐sectional study
Authors: Martín‐Pujol Anna , Fernández Esteve , Schiaffino Anna , Moncada Albert , Ariza Carles , Blanch Carles , Martínez‐Sánchez Jose M ,   the RESPIR·NET research group
Published: April 2013

Aim

To analyse the association between tobacco smoking, exposure to second‐hand smoke (SHS) and reports of wheezing and asthma in a sample of schoolchildren.

Methods

A structured questionnaire was administered to 1766 students (7th grade, aged 12–13 years) at 25 schools in Terrassa, Spain (2006). We determined the prevalence of active smoking, exposure to SHS and reports of wheezing and asthma, and their association by means of prevalence odds ratios (OR) and 95% confidence intervals (CI).

Results

97.5% of children were nonsmokers, 1.5% were experimental smokers and 1% were regular smokers. 41.1% of children reported exposure to SHS at home, 40.0% at school, 53.9% in their leisure time and 33.2% while using private or public transportation. Wheezing was reported by 9.2% of children, and 9.2% reported asthma. A significant association was found between smoking tobacco and wheezing: OR in experimental smokers = 3.0 (95% CI 1.2–7.7), and OR in active smokers = 4.2 (95% CI 1.4–12.5). Exposure to SHS while using transportation was associated with wheezing (OR = 1.4; 95% CI 1.0–2.0). Tobacco smoking and exposure to SHS were not associated with asthma.

Conclusion

Active and experimental smokers, and those who reported exposure to SHS while using public or private transportation, had higher likelihood of reporting wheezing. No association between active or passive smoking and asthma was observed.
Autism spectrum disorders: head circumference and body length at birth are both relative
Authors: Grandgeorge Marine , Lemonnier Eric , Jallot Nelle
Published: April 2013

Aim

Although the body length and weight of an infant are related to head circumference, little research on ASDs has examined these factors. Our study compared the head circumferences of neonates who were later diagnosed with ASD with a control group. Additional comparisons on morphological disproportions at birth included the head circumference‐to‐height and head circumference‐to‐weight ratios.

Methods

We recruited 422 children with ASD and 153 typically developing children. Head circumference, body length and weight at birth were collected and standardized as percentile scores according to gestational age and gender.

Results

Our results revealed that genuine macrocephaly was significantly higher in children with other pervasive developmental disorders compared with the control group. This difference was not observed with regard to genuine microcephaly. Relative macrocephaly and relative microcephaly were significantly more frequent in children with autism disorder compared with the control group with regard to body length.

Conclusions

The differences in relative macrocephaly and microcephaly, as well as in other parameters, between diagnostic subgroups suggest that the presence of several neurological mechanisms plays a role in the later expression of different phenotypes. An increased head circumference‐to‐body length ratio in newborns may be a factor to follow that could be related to ASD.
Src homology 2‐containing protein tyrosine phosphatase‐2 acts as a negative regulator for MUC5AC transcription via the inhibition of the ERK1/2 MAPK signalling pathway in the airway
Authors: Song K. S. , Choi J. K. , Ahn D. W.
Published: April 2013

Aims

Mucus hypersecretion has been frequently observed in inflammation respiratory diseases. However, the negative regulators for mucus overproduction have not been readily identified. Our work focused on identifying novel negative regulator that modulates mucus overproduction in the human respiratory system. Herein, we examined whether H2O2 could induce MUC5AC transcription in a dose‐dependent manner and activate tyrosine phosphatase (SHP)‐2 in human airway epithelial cells.

Methods

We performed qRT‐PCR to detect the changes in MUC5AC transcription and dot‐blotting analysis to investigate MUC5AC secretion as regulated by SHP‐2.

Results

H2O2 induced MUC5AC transcription in a dose‐dependent manner and dramatically activated SHP‐2. In addition, whereas wild‐type SHP‐2 completely inhibited H2O2‐induced MUC5AC transcription, siRNA‐SHP‐2 restored it interestingly, suggesting that SHP‐2 may act as a negative regulator for mucus overproduction and hypersecretion in the human respiratory tract. Moreover, SHP‐2 inhibited the ERK1/2 MAPK pathway, thus abolishing the signalling for MUC5AC transcription.

Conclusion

We found that H2O2 induced SHP‐2 activation, which acted as a suppressor in H2O2 signalling to regulate MUC5AC transcription in the airway.
Sulphide signalling potentiates apoptosis through the up‐regulation of IP3 receptor types 1 and 2
Authors: Lencesova L. , Hudecova S. , Csaderova L. , Markova J. , Soltysova A. , Pastorek M. , Sedlak J. , Wood M. E. , Whiteman M. , Ondrias K. , Krizanova O.
Published: April 2013

Aim

To investigate an interaction between the calcium and sulphide signalling pathways, particularly effects of the slow H2S release donor morpholin‐4‐ium‐4‐methoxyphenyl‐(morpholino)‐phosphinodithioate (GYY4137) on the expression of inositol 1,4,5‐trisphosphate receptors (IP3R) with the possible impact on the apoptosis induction in HeLa cells.

Methods

Gene expression, Western blot analysis, apoptosis determination by Annexin‐V‐FLUOS and drop in mitochondrial membrane potential by 5,5′,6,6′‐tetrachloro‐1,1′,3,3′‐tetraethylbenzimidazolyl‐carbocyanine iodide (JC1) and immunofluorescence were used to determine differences in control and GYY4137‐treated HeLa cells.

Results

In HeLa cell line, GYY4137 (10 μm) up‐regulated expression of the IP3R1 and IP3R2, but not IP3R3 on both mRNA and protein levels. Concurrently, cytosolic calcium increased and reticular calcium was depleted in concentration‐dependent manner, partially by the involvement of IP3R. Depletion of calcium from reticulum was accompanied by increase in endoplasmic reticulum (ER) stress markers, such as X‐box, CHOP and ATF4, thus pointing to the development of ER stress due to GYY4137 treatment. Also, GYY4137 treatment of HeLa cells increased the number of apoptotic cells.

Conclusion

These results suggest an involvement of H2S in both IP3‐induced calcium signalling and induction of apoptosis, possibly through the activation of ER stress.
Choosing a DIVA: a comparison of emerging digital imagery vegetation analysis techniques
Authors: Jorgensen Christopher F. , Stutzman Ryan J. , Anderson Lars C. , E. Decker Suzanne , Powell Larkin A. , Schacht Walter H. , Fontaine Joseph J.
Published: April 2013

Question

What is the precision of five methods of measuring vegetation structure using ground‐based digital imagery and processing techniques?

Location

Lincoln, Nebraska, USA

Methods

Vertical herbaceous cover was recorded using digital imagery techniques at two distinct locations in a mixed‐grass prairie. The precision of five ground‐based digital imagery vegetation analysis (DIVA) methods for measuring vegetation structure was tested using a split‐split plot analysis of covariance. Variability within each DIVA technique was estimated using coefficient of variation of mean percentage cover.

Results

Vertical herbaceous cover estimates differed among DIVA techniques. Additionally, environmental conditions affected the vertical vegetation obstruction estimates for certain digital imagery methods, while other techniques were more adept at handling various conditions. Overall, percentage vegetation cover values differed among techniques, but the precision of four of the five techniques was consistently high.

Conclusions

DIVA procedures are sufficient for measuring various heights and densities of standing herbaceous cover. Moreover, digital imagery techniques can reduce measurement error associated with multiple observers' standing herbaceous cover estimates, allowing greater opportunity to detect patterns associated with vegetation structure.
Prolonged inhibition of 5‐HT3 receptors by palonosetron results from surface receptor inhibition rather than inducing receptor internalization
Authors: Hothersall J Daniel , Moffat Christopher , Connolly Christopher N
Published: April 2013

Background and Purpose

The 5‐HT3 receptor antagonist palonosetron is an important treatment for emesis and nausea during cancer therapy. Its clinical efficacy may result from its unique binding and clearance characteristics and receptor down‐regulation mechanisms. We investigated the mechanisms by which palonosetron exerts its long‐term inhibition of 5‐HT3 receptors for a better understanding of its clinical efficacy.

Experimental Approach

Cell surface receptors (recombinantly expressed 5HT3A or 5HT3AB in COS‐7 cells) were monitored using [3H]granisetron binding and ELISA after exposure to palonosetron. Receptor endocytosis was investigated using immunofluorescence microscopy.

Key Results

Chronic exposure to palonosetron reduced the number of available cell surface [3H]granisetron binding sites. This down‐regulation was not sensitive to either low temperature or pharmacological inhibitors of endocytosis (dynasore or nystatin) suggesting that internalization did not play a role. This was corroborated by our observation that there was no change in cell surface 5‐HT3 receptor levels or increase in endocytic rate. Palonosetron exhibited slow dissociation from the receptor over many hours, with a significant proportion of binding sites being occupied for at least 4 days. Furthermore, our observations suggest that chronic receptor down‐regulation involved interactions with an allosteric binding site.

Conclusions and Implications

Palonosetron acts as a pseudo‐irreversible antagonist causing prolonged inhibition of 5‐HT3 receptors due to its very slow dissociation. In addition, an irreversible binding mode persists for at least 4 days. Allosteric receptor interactions appear to play a role in this phenomenon.
Faunal turnover of marine tetrapods during the Jurassic–Cretaceous transition
Authors: Benson Roger B. J. , Druckenmiller Patrick S.
Published: April 2013

Marine and terrestrial animals show a mosaic of lineage extinctions and diversifications during the Jurassic–Cretaceous transition. However, despite its potential importance in shaping animal evolution, few palaeontological studies have focussed on this interval and the possible climate and biotic drivers of its faunal turnover. In consequence evolutionary patterns in most groups are poorly understood. We use a new, large morphological dataset to examine patterns of lineage diversity and disparity (variety of form) in the marine tetrapod clade Plesiosauria, and compare these patterns with those of other organisms. Although seven plesiosaurian lineages have been hypothesised as crossing the Jurassic–Cretaceous boundary, our most parsimonious topology suggests the number was only three. The robust recovery of a novel group including most Cretaceous plesiosauroids (Xenopsaria, new clade) is instrumental in this result. Substantial plesiosaurian turnover occurred during the Jurassic–Cretaceous boundary interval, including the loss of substantial pliosaurid, and cryptoclidid diversity and disparity, followed by the radiation of Xenopsaria during the Early Cretaceous. Possible physical drivers of this turnover include climatic fluctuations that influenced oceanic productivity and diversity: Late Jurassic climates were characterised by widespread global monsoonal conditions and increased nutrient flux into the opening Atlantic‐Tethys, resulting in eutrophication and a highly productive, but taxonomically depauperate, plankton. Latest Jurassic and Early Cretaceous climates were more arid, resulting in oligotrophic ocean conditions and high taxonomic diversity of radiolarians, calcareous nannoplankton and possibly ammonoids. However, the observation of discordant extinction patterns in other marine tetrapod groups such as ichthyosaurs and marine crocodylomorphs suggests that clade‐specific factors may have been more important than overarching extrinsic drivers of faunal turnover during the Jurassic–Cretaceous boundary interval.
Design and Synthesis of a Tetrahydroisoquinoline‐Based Hydroxamate Derivative (ZYJ‐34v), An Oral Active Histone Deacetylase Inhibitor with Potent Antitumor Activity
Authors: Zhang Yingjie , Liu Chunxi , Chou C. James , Wang Xuejian , Jia Yuping , Xu Wenfang
Published: April 2013

In our previous study, we developed a novel series of tetrahydroisoquinoline‐based hydroxamic acid derivatives as histone deacetylase inhibitors (Bioorg Med Chem, 2010, 18, 1761–1772; J Med Chem, 2011, 54, 2823–2838), among which, compound ZYJ‐34c (1) was identified and validated as the most potent one with marked in vitro and in vivo antitumor potency (J Med Chem, 2011, 54, 5532–5539.). Herein, further modification in 1 afforded another oral active analog ZYJ‐34v (2) with simplified structure and lower molecular weight. Biological evaluation of compound 2 showed efficacious inhibition against histone deacetylase 1, 2, 3, and 6, which was confirmed by Western blot analysis results. Most importantly, compound 2 exhibited similar even more potent in vitro and in vivo antitumor activities relative to the approved histone deacetylase inhibitor SAHA.
Smoking and thyroid
Authors: Wiersinga Wilmar M.
Published: April 2013

Current smoking in population surveys is associated with a slight dose‐dependent fall of serum TSH, likely secondary to a rise of serum FT4 and FT3 induced by activation of the sympathetic nervous system; it is independent of iodine intake. In contrast, the slightly greater thyroid size in smokers is observed in iodine‐deficient but not in iodine‐sufficient areas and caused by competitive inhibition of thyroidal iodide uptake by thiocyanate. Smokers have an increased prevalence of nontoxic goitre and thyroid multinodularity, at least in iodine‐deficient areas. Current smoking reduces dose dependently the risk of thyroid cancer, which is more pronounced for papillary than for follicular types; the risk in former smokers approaches that of never smokers. The lower TSH and lower body mass index in smokers might contribute to this reduced risk. Current smoking lowers the risk of developing thyroid peroxidase and thyroglobulin antibodies and subclinical and overt autoimmune hypothyroidism; the effect is dose dependent, but disappears within 3 years after quitting smoking. There is evidence from an animal model of experimental autoimmune thyroiditis that anti‐inflammatory effects of nicotine are involved. In contrast, smoking is a dose‐dependent risk factor for Graves’ hyperthyroidism and especially for Graves’ ophthalmopathy. Smoking is related to a higher recurrence rate of Graves’ hyperthyroidism, a higher risk on Graves’ ophthalmopathy after 131I therapy and a less favourable outcome of GO treatment with steroids or retrobulbar irradiation. The observed associations with smoking likely indicate causal relationships in view of consistent associations across studies, the presence of dose–response effects and disappearance of associations after cessation of smoking.
‘Deletion rescue’ by mitotic 11q uniparental disomy in a family with recurrence of 11q deletion Jacobsen syndrome
Authors: Johnson J.P. , Haag M. , Beischel L. , McCann C. , Phillips S. , Tunby M. , Hansen J. , Schwanke C. , Reynolds J.F.
Published: April 2013

We describe a family with recurrent 11q23‐qter deletion Jacobsen syndrome in two affected brothers, with unique mosaic deletion ‘rescue’ through development of uniparental disomy (UPD) in the mother and one of the brothers. Inheritance studies show that the deleted chromosome is of maternal origin in both boys, and microarray shows a break near the ASAM gene. Parental lymphocyte chromosomes were normal. However, the mother is homozygous in lymphocytes for all loci within the deleted region in her sons, and presumably has UPD for this region. In addition, she is mosaic for the 11q deletion seen in her sons at a level of 20–30% in skin fibroblasts. We hypothesize that one of her #11 chromosomes shows fragility, that breakage at 11q23 occurred with telomeric loss in some cells, but ‘rescue’ from the deletion occurred in most cells by the development of mitotic UPD. She apparently carries the 11q deletion in her germ line resulting in recurrence of the syndrome. The older son is mosaic for the 11q cell line (70–88%, remainder 46,XY), and segmental UPD11 ‘rescue’ apparently also occurred in his cytogenetically normal cells. This is a novel phenomenon restoring disomy to an individual with a chromosomal deletion.
Patient‐reported outcomes of maxillary implant‐supported overdentures compared with conventional dentures
Authors: Zembic Anja , Wismeijer Daniel
Published: April 2013

Objective

The aim of the present prospective clinical study was to compare patient‐reported outcomes for maxillary conventional dentures and maxillary implant‐supported dentures.

Material and methods

Twenty‐one patients (6 women and 15 men) being edentulous in the maxilla and encountering problems with their existing dentures were included. Twelve patients (4 women and 8 men) received a new set of conventional dentures, due to insufficient dentures. In nine patients (2 women and 7 men), the existing dentures were adjusted by means of relining or rebasing. All patients received implant‐supported dentures on two retentive anchors. In total, 42 implants were inserted in the anterior maxilla. The participants rated their satisfaction on their existing conventional dentures, 2 months after insertion of new conventional dentures and 2 months after insertion of implant‐supported dentures. Thereby, patients responded to questionnaires capturing the oral health impact profile (OHIP) using visual analog scales. Seven domains (functional limitation, physical pain, psychological discomfort, physical, psychological and social disability and handicap) were assessed. Higher scores implied poorer patient satisfaction. In addition, the questionnaire involved the evaluation of cleaning ability, general satisfaction, speech, comfort, esthetics, stability, and chewing ability. Higher scores implied higher patient satisfaction.

Results

Patient satisfaction significantly increased for implant‐supported dentures compared with old dentures in all seven OHIP subgroups, as well as for cleaning ability, general satisfaction, ability to speak, comfort, esthetics, and stability (P < 0.05). The comparison of new conventional dentures and implant‐supported dentures revealed a statistically significantly increased satisfaction for functional limitation (difference of 33.2 mm), psychological discomfort (difference of 36.7 mm), physical disability (difference of 36.3 mm), and social disability (difference of 23.5 mm), (P < 0.05). Additionally, general satisfaction, chewing ability, speech, and stability significantly improved in implant‐supported dentures (P < 0.05).

Conclusions

Within the limits of this study, maxillary dentures retained by two implants provided some significant short‐term improvements over conventional dentures in oral‐ and health‐related quality of life.
Zinc Promotes the Death of Hypoxic Astrocytes by Upregulating Hypoxia‐Induced Hypoxia‐Inducible Factor‐1alpha Expression via Poly(ADP‐ribose) Polymerase‐1
Authors: Pan Rong , Chen Chen , Liu Wen‐Lan , Liu Ke‐Jian
Published: April 2013

Aim

Pathological release of excess zinc ions has been implicated in ischemic brain cell death. However, the underlying mechanisms remain to be elucidated. In stroke, ischemia‐induced zinc release and hypoxia‐inducible factor‐1 (HIF‐1) accumulation concurrently occur in the ischemic tissue. The present study tests the hypothesis that the presence of high intracellular zinc concentration is a major cause of modifications to PARP‐1 and HIF‐1α during hypoxia, which significantly contributes to cell death during ischemia.

Methods

Primary cortical astrocytes and C8‐D1A cells were exposed to different concentrations of zinc chloride. Cell death rate and protein expression of HIF‐1 and Poly(ADP‐ribose) polymerase (PARP)‐1 were examined after 3‐h hypoxic treatment.

Results

Although 3‐h hypoxia or 100 μM of zinc alone did not induce noticeable cytotoxicity, their combination led to a dramatic increase in astrocytic cell death in a zinc‐concentration‐dependent manner. Exposure of astrocytes to hypoxia for 3 h remarkably increased the levels of intracellular zinc and HIF‐1α protein, which was further augmented by added exogenous zinc. Notably, HIF‐1α knockdown blocked zinc‐induced astrocyte death. Moreover, knockdown of PARP‐1, another important protein in the response of hypoxia, attenuated the overexpression of HIF‐1α and reduced the cell death rate.

Conclusions

Our studies show that zinc promotes hypoxic cell death through overexpression of the hypoxia response factor HIF‐1α via the cell fate determine factor PARP‐1 modification, which provides a novel mechanism for zinc‐mediated ischemic brain injury.
The effectiveness of secondary and tertiary care lifestyle intervention in morbidly obese patients: a 1‐year non‐randomized controlled pragmatic clinical trial
Authors: Gjevestad E. , Karlsen T. I. , Røislien J. , Mæhlum S. , Hjelmesæth J.
Published: April 2013

In this non‐randomized clinical pragmatic trial, we aimed to compare the effectiveness of an outpatient intensive lifestyle intervention (ILI) programme conducted in a tertiary care obesity rehabilitation centre with an outpatient moderate lifestyle intervention (MLI) programme at a secondary care obesity centre. Effectiveness was measured in terms of the 1‐year effect each programme had on body weight, physical activity and health‐related quality of life (HRQL). A total of 232 morbidly obese subjects were recruited to the ILI group and 140 to the MLI group, with retention rates of 78% and 44%, respectively. The ILI group had a significantly larger mean (95% confidence interval [CI]) weight loss than the MLI group, 11% (9%, 12%) vs. 2% (1%, 6%), P < 0.001, and a larger proportion of completers attaining ≥5% weight loss (71% vs. 33%), P < 0.001. Compared with the MLI group, the ILI group achieved a significant larger mean (95% CI) increase in the physical dimension of HRQL 6.9 (4.4, 9.3), P < 0.001, the mental dimension of HRQL 4.4 (1.4, 7.4), P = 0.018 and in the emotional dimension of HRQL 17.8 (12.8, 22.6), P < 0.001. There were no significant differences in terms of changes in physical activity. Compared with MLI, ILI was associated with significantly larger weight loss and better HRQL.
The importance of lymph node retrieval and lymph node ratio following preoperative chemoradiation of rectal cancer
Authors: La Torre M. , Mazzuca F. , Ferri M. , Mari F. S. , Botticelli A. , Pilozzi E. , Lorenzon L. , Osti M. F. , Marchetti P. , Enrici R. M. , Ziparo V.
Published: April 2013

Aim

Preoperative chemoradiation (CRT) for rectal cancer decreases the number of examined lymph nodes (NELN) found in the resected specimen. However, the prognostic role of lymph node evaluation including overall numbers and the lymph node ratio (LNR) in patients having preoperative CRT have not yet been defined. The study has assessed the influence of CRT on the NELN and on lymph node number and LNR on the survival of patients with rectal cancer.

Method

Between 2003 and 2011, 508 patients with nonmetastatic rectal cancer underwent mesorectal excision. Of these 123 (24.2%) received preoperative CRT. Univariate and multivariate analysis was performed to define the role of NELN and LNR as prognostic indicators of survival.

Results

Neoadjuvant CRT significantly reduced the NELN (P < 0.0001). Disease‐free survival (DFS) and overall survival (OS) of patients with fewer or more than 12 nodes retrieved did not differ statistically. Node‐negative patients with six or fewer lymph nodes were significantly associated with a poor DFS and OS on univariate analysis (P = 0.03 and P = 0.03). LNR significantly influenced the DFS and OS on multivariate analysis [DFS, P = 0.0473, hazard ratio (HR) 2.4980, 95% confidence interval (CI) 1.2631–9.4097; OS, P = 0.0419, HR 1.1820, 95% CI 1.1812–10,710].

Conclusion

The cut‐off of 12 lymph nodes does not influence survival and should not be considered for cancer‐specific prediction of patients having neoadjuvant CRT. In contrast LNR is an independent prognostic predictor of DFS and OS in such patients.
Bowel dysfunction after low anterior resection with and without neoadjuvant therapy for rectal cancer: a population‐based cross‐sectional study
Authors: Bregendahl S. , Emmertsen K. J. , Lous J. , Laurberg S.
Published: April 2013

Aim

Bowel dysfunction was assessed after low anterior resection with and without neoadjuvant therapy (NT) for rectal cancer using a novel symptom‐based scoring system correlated with quality of life.

Method

We identified all patients who underwent curative resection for rectal cancer in Denmark between 2001 and 2007. A questionnaire on bowel function and quality of life, including the recently validated low anterior resection syndrome score (LARS score; range 0–42) was administered to recurrence‐free patients in 2009. We used multivariate analysis to examine the association between major LARS (LARS score ≥ 30) and a number of patient and treatment‐related factors.

Results

Of 1087 eligible patients, 980 agreed to participate and, of these, 938 were included in the analysis. Major LARS was observed in 41%. The use of NT (OR = 2.48; 95% CI: 1.73–3.55), long‐course chemoradiotherapy vs short‐course radiotherapy (OR = 0.90; 95% CI: 0.44–1.87), total mesorectal excision (TME) vs partial mesorectal excision (PME) (OR = 2.31; 95% CI: 1.69–3.16), anastomotic leakage (OR = 2.06; 95% CI: 0.93–4.55), age ≤ 64 years at surgery (OR = 1.90; 95% CI: 1.43–2.51) and female gender (OR = 1.35; 95% CI 1.02–1.79) were associated with major LARS. No association was found between major LARS and the time since surgery (OR = 0.78; 95% CI: 0.59–1.04) or neorectal reconstruction (colonic pouch vs straight colorectal or side‐to‐end anastomosis (OR = 0.96; 95% CI: 0.63–1.46).

Conclusion

Severe bowel dysfunction is a frequent long‐term outcome after resection for rectal cancer. Use of NT, regardless of a long‐ or short‐course protocol, and TME (compared with PME) are strong independent risk factors for major LARS.