bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquired equine polyneuropathy in Norway and Sweden: A clinical and epidemiological study
Authors: Gröndahl G. , Hanche‐Olsen S. , Bröjer J. , Ihler C. F. , Hultin Jäderlund K. , Egenvall A.
Published: November 2012

Reasons for performing study

Acquired equine polyneuropathy (AEP, also known as ‘Scandinavian knuckling syndrome’), is a serious disease of unknown aetiology, which emerged clustering in horse farms in Sweden, Norway and Finland in the 1990s. Clinical and epidemiological data regarding the syndrome are scarce.

Objectives

To describe the clinical and epidemiological findings and outcome in outbreaks of AEP and compare risk factors in affected and unaffected horses on affected farms in Norway and Sweden during 2007–2009.

Methods

Neurological examinations were performed and data collected regarding demography, usage, turning‐out, feeding, prophylactic strategies and long‐term outcome.

Results

Thirteen affected farms with 157 horses of various breeds, of which 42 were AEP cases, were studied. Typical digital extensor dysfunction and knuckling of pelvic limbs were noted in 34 definitive cases. Eight additional plausible cases had a severe, acute course of neurological disease. There were no signs of brain or cranial nerve dysfunction. Cases occurred from December to April, with new cases emerging within 100 days of the index case. Affected and unaffected horses were fed wrapped forage. Prevalence for AEP was 27% and case fatality 29%. The median duration of AEP in survivors was 4.4 months (1–17 months). Survivors returned to full work within 19 months (median 6.6 months). Acquired equine polyneuropathy was less prevalent in horses aged >12 years and young horses had a higher chance of survival than older horses. Management factors did not differ between affected and unaffected horses.

Conclusions

Acquired equine polyneuropathy is a potentially fatal neurological disease characterised by pelvic limb knuckling. Surviving horses returned to normal function after a long period of rest. Cases were clustered in farms during the winter/spring season. Wrapped forage was used in all farms.

Potential relevance

The results provide valuable insights into the clinical examination, handling and prognosis of cases of AEP, an emerging neurological disease of unknown aetiology in horses.
Equine colostral carbohydrates reduce lipopolysaccharide‐induced inflammatory responses in equine peripheral blood mononuclear cells
Authors: Vendrig J. C. , Coffeng L. E. , Fink‐Gremmels J.
Published: November 2012

Reasons for performing study

Increasing evidence suggests that reactions to lipopolysaccharide (LPS), particularly in the gut, can be partly or completely mitigated by colostrum‐ and milk‐derived oligosaccharides. Confirmation of this hypothesis could lead to the development of new therapeutic concepts.

Objectives

To demonstrate the influence of equine colostral carbohydrates on the inflammatory response in anin vitromodel with equine peripheral blood mononuclear cells (PBMCs).

Methods

Carbohydrates were extracted from mare colostrum, and then evaluated for their influence onLPS‐induced inflammatory responses inPBMCsisolated from the same mares.mRNAexpression of tumour necrosis factor‐α, interleukin‐6 and interleukin‐10 was measured as well as the protein levels of tumour necrosis factor‐α (TNF‐α) and interleukin‐10 (IL‐10).

Results

Equine colostral carbohydrates significantly reducedLPS‐inducedTNF‐α protein at both times measured and significantly reducedLPS‐inducedTNF‐α,IL‐6 andIL‐10mRNAexpression byPBMCs. Moreover, cell viability significantly increased in the presence of high concentrations of colostral carbohydrates.

Conclusions

Carbohydrates derived from equine colostrum reduceLPS‐induced inflammatory responses of equinePBMCs.

Potential relevance

Colostrum and milk‐derived carbohydrates are promising candidates for new concepts in preventive and regenerative medicine.
A Composite Case Study of a Woman With Human Immunodeficiency Virus: Integration of Nursing Research and Theory With Practice
Authors: Reyes Darcel
Published: November 2012

Purpose

The purpose of this case study is to demonstrate integration of the research‐based standardized languages of NANDA‐I, the Nursing Outcomes Classification (NOC), and the Nursing Interventions Classification (NIC) with Barrett's middle range theory of power to support a woman's experience of ending sexual exploitation and stopping drug use.

Data Source

Clinical practice, the collective experiences of patients, research evidence, and books that explain NANDA‐I, NOC, and NIC.

Data Synthesis

The success of this woman in managing her health supports the use of Barrett's theory of power.

Conclusion

Theory and research provide the foundations for quality‐based clinical practice.

Implications for Nursing Practice

Identification of readiness to change enabled significant life changes.
Delineating the practice profile of advanced practice nursing: a cross‐sectional survey using the modified strong model of advanced practice
Authors: Gardner Glenn , Chang Anne M. , Duffield Christine , Doubrovsky Anna
Published: November 2012

Aims

To test a model that delineates advanced practice nursing from the practice profile of other nursing roles and titles.

Background

There is extensive literature on advanced practice reporting the importance of this level of nursing to contemporary health service and patient outcomes. Literature also reports confusion and ambiguity associated with advanced practice nursing. Several countries have regulation and delineation for the nurse practitioner, but there is less clarity in definition and service focus of other advanced practice nursing roles.

Design

A statewide survey.

Methods

Using the modified Strong Model of Advanced Practice Role Delineation tool, a survey was conducted in 2009 with a random sample of registered nurses/midwives from government facilities in Queensland, Australia. Analysis of variance compared total and subscale scores across groups according to grade. Linear, stepwise multiple regression analysis examined factors influencing advanced practice nursing activities across all domains.

Results

There were important differences according to grade in mean scores for total activities in all domains of advanced practice nursing. Nurses working in advanced practice roles (excluding nurse practitioners) performed more activities across most advanced practice domains. Regression analysis indicated that working in clinical advanced practice nursing roles with higher levels of education were strong predictors of advanced practice activities overall.

Conclusion

Essential and appropriate use of advanced practice nurses requires clarity in defining roles and practice levels. This research delineated nursing work according to grade and level of practice, further validating the tool for the Queensland context and providing operational information for assigning innovative nursing service.
Oregon Hydrologic Landscapes: A Classification Framework1
Authors: Wigington Parker J. , Leibowitz Scott G. , Comeleo Randy L. , Ebersole Joseph L.
Published: November 2012

Wigington, Parker J., Jr., Scott G. Leibowitz, Randy L. Comeleo, and Joseph L. Ebersole, 2012. Oregon Hydrologic Landscapes: A Classification Framework. Journal of the American Water Resources Association (JAWRA) 1‐20. DOI: 10.1111/jawr.12009

Abstract:  There is a growing need for hydrologic classification systems that can provide a basis for broad‐scale assessments of the hydrologic functions of landscapes and watersheds and their responses to stressors such as climate change. We developed a hydrologic landscape (HL) classification approach that describes factors of climate‐watershed systems that control the hydrologic characteristics of watersheds. Our assessment units are incremental watersheds (i.e., headwater watersheds or areas draining directly into stream reaches). Major components of the classification include indices of annual climate, climate seasonality, aquifer permeability, terrain, and soil permeability. To evaluate the usefulness of our approach, we identified 30 rivers with long‐term streamflow‐gauging records and without major diversions and impoundments. We used statistical clustering to group the streams based on the shapes of their annual hydrographs. Comparison of the streamflow clusters and HL distributions within river basin clusters shows that the Oregon HL approach has the ability to provide insights about the expected hydrologic behavior of HLs and larger river basins. The Oregon HL approach has potential to be a useful framework for comparing hydrologic attributes of streams and rivers in the Pacific Northwest.
Drawbacks to palaeodistribution modelling: the case of South American seasonally dry forests
Authors: Collevatti Rosane G. , Terribile Levi Carina , de Oliveira Guilherme , Lima‐Ribeiro Matheus S. , Nabout João C. , Rangel Thiago F. , Diniz‐Filho Jose Alexandre F.
Published: November 2012

Aim

Species distribution modelling (SDM) has increasingly been used to predict palaeodistributions at regional and global scales in order to understand the response of vegetation to climate change and to estimate palaeodistributions for the testing of biogeographical hypotheses. However, there are many sources of uncertainty in SDM that may restrict the ability of models to hindcast palaeo‐distributions and provide a basis for hypothesis testing in molecular phylogenetics and phylogeographical studies.

Location

Seasonally dry forests (SDFs) in South America.

Methods

We addressed the problem of using palaeodistribution modelling for SDFs based on the projection of their current distribution into past environments (21 ka) using 11 methods for SDMs and five coupled atmosphere–ocean global circulation models (AOGCMs) for 16 species.

Results

We observed considerable uncertainty in the hindcasts, with the most important effects for AOGCM (median 12.2%), species (median 15.6%) and their interaction (median 13.6%). The effects of AOGCMs were stronger in the Amazon region, whereas the species effect occurred primarily in the dry areas of central Brazil. The log‐linear model detected significant effects of the three sources of variation and their interaction on the classification of each map in supporting alternative hypotheses. An expansion scenario combining the Pleistocene arc and Amazonian expansion, and Pennington's Amazonian expansion alone, were the most frequently supported palaeodistribution scenarios.

Main conclusions

As a basis for evaluating a given hypothesis, hindcast distributions must be used in direct association with other evidence, such as molecular variation and the fossil record. We propose an alternative framework concerning hypothesis testing that couples SDM and phylogeographical work, in which palaeoclimatic distributions and other sources of information, such as the pollen fossil record and coalescence modelling, must be weighted equally.
Biogeography of Trimerotropis pallidipennis (Acrididae: Oedipodinae): deep divergence across the Americas
Authors: Husemann Martin , Guzman Noelia Verónica , Danley Patrick D. , Cigliano Maria Marta , Confalonieri Viviana Andrea
Published: November 2012

Aim

Trimerotropis pallidipennis represents a species complex of band‐winged grasshopper distributed over North and South America. Previous studies indicated a North American origin of the species and suggested that colonization of South America occurred during the Pleistocene after the closure of the Isthmus of Panama. Here we use a phylogeographical approach in order to test different biogeographical scenarios and determine how many distinct units exist within the species complex.

Location

North and South America with specific emphasis on the Andes mountains of South America.

Methods

We sequenced two mitochondrial and two nuclear genes for multiple specimens belonging to each taxonomic unit. Using the concatenated dataset and a coalescent‐based approach we estimated the phylogeny of the complex. In order to distinguish the different biogeographical and species delimitation hypotheses we constrained our dataset to different taxon sets and ran Bayesian analyses in *beast. Posterior probabilities and DensiTree plots allowed us to determine the best hypotheses. We used a molecular clock approach to correlate geological events with observed phylogenetic splits.

Results

All analyses indicate the existence of at least three distinct genetic lineages: Trimerotropis pallidipennis from North America, Trimerotropis ochraceipennis from Chile and an undescribed Trimerotropis species from Argentina. The split between North and South American forms took place about 1.3 Ma, long after the Isthmus of Panama had been completed. Biogeographical analyses suggest a first dispersal event from North to South America. Subsequent dispersion and vicariance probably led to the differentiation of the endemics now found in Chile and Argentina.

Main conclusions

We demonstrate the existence of three distinct genetic lineages in the Trimerotropis pallidipennis species complex. These lineages are also chromosomally differentiated as previous studies have indicated. Dispersion of T. pallidipennis from North to South America probably occurred during the early Pleistocene, when climatic conditions were more suitable. Subsequent diversification in South America was the result of range expansion and vicariance, possibly in response to later Pleistocene glaciations of the Andes.
Opinion of residents from the Gold Coast, Queensland, on community water fluoridation
Authors: Kroon Jeroen , Reid Kate Emily , Cutting Jenna Renae , Lalloo Ratilal , Chiu Kandy Chien
Published: November 2012

Objective

To investigate opinions and concerns of Gold Coast residents regarding fluoridation of community water supplies.

Material and methods

Anonymous data were collected in four major shopping centers from approximately 500 Gold Coast residents.

Results

Eighty‐one percent of participants were aware of the addition of fluoride to the water supply. More than half obtained information on water fluoridation through the print and electronic media. Sixty percent of respondents supported water fluoridation. The majority preferred the public and/or health professionals to have made the decision on water fluoridation rather than the government. The percentage of residents supporting water fluoridation was lower than that found in other Queensland, Australian, and worldwide surveys. In this study, only age and the highest level of education attained were factors significantly related to levels of support for water fluoridation.

Conclusion

The Queensland Government's decision to implement water fluoridation without a referendum caused disquiet amongst some Gold Coast residents. Future public health initiatives therefore may be assisted by more consultation with, and involvement from, health professionals in the relevant fields. Public health campaigns may benefit more from interaction with the community in order to address their specific concerns.
RUNX2 gene status in a cleidocranial dysplasia patient without supernumerary teeth
Authors: Anthonappa Robert P. , King Nigel M. , Mahmoud Rabie Abou‐Bakr
Published: November 2012

Objective

This study sought to perform mutational analysis of the RUNX2 gene in an 8‐year‐old girl with a diagnosis of cleidocranial dysplasia (CCD) without supernumerary teeth (proband) and her parents, plus in age and gender matched control subjects.

Methods

Ethical approval and informed consent was obtained for this study. Blood samples were obtained and the isolated DNA was used to amplify exons 0–7 of the RUNX2 gene using specific primers, which was subsequently sequenced.

Results

No mutations were identified in the coding regions of the RUNX2 gene.

Conclusion

The absence of supernumerary teeth in this individual with CCD demonstrates that there are variations in the phenotypes and mere absence of mutations does not imply that CCD phenotype is not governed by RUNX2 gene as only two‐thirds of the individuals exhibiting a CCD phenotype would reveal a RUNX2 mutation; therefore, the influence of copy number variations including large insertions, intragenic deletions, duplications, and inversions of genes cannot be excluded completely.
Nurses' perceptions of standardised assessment and prevention of complications in an ICU
Authors: Soh Kim Lam , Davidson Patricia M , Leslie Gavin , DiGiacomo Michelle , Soh Kim Geok
Published: November 2012

Aims and objectives

To describe nurses' perceptions of evidence‐based recommendations to prevent complications in a Malaysian intensive care unit.

Background

Ventilator‐associated pneumonia, catheter‐related blood stream infection and pressure ulcer are three frequent adverse events in the intensive care unit. Implementing evidenced‐based practice is critical in prevention of these complications.

Design

A qualitative focus group study.

Methods

Focus groups were conducted with nurses in the intensive care unit of a regional hospital in Malaysia following evidence‐based interventions. Focus group transcripts were analysed using the method of thematic analyses.

Results

Thirty‐four nurses participated in eight focus groups. The main themes derived from the interviews: (1) nurses' knowledge impacts on the change process; (2) initial resistance, ambivalence and movement to acceptance; and (3) hierarchical organisational structure can hinder the change process.

Conclusion

Enhancing nurses' knowledge and attitudes of evidence‐based practice, providing them with tools to monitor their clinical practice, and empowering them to change practice are likely to be important in influencing clinical outcomes. Increasing the emphasis on evidence‐based practice in nursing curricula and engaging in cultural change processes in the workplace are necessary to improve clinical outcomes.

Relevance to clinical practice

These findings provide valuable information for implementing clinical practice improvement interventions.
Study of apoptosis in oral pemphigus vulgaris using immunohistochemical marker Bax and TUNEL technique
Authors: Deyhimi Parviz , Tavakoli Payam
Published: November 2012

Background

Pemphigus vulgaris (PV) is an autoimmune mucocutaneous disease presenting clinically with blisters or erosions of the skin and mucous membrane. The main histopathologic characteristic of this disease is suprabasal vesicles due to loss of cell–cell adhesion between keratinocytes named acantholysis. Studies have shown that apoptosis is increased in PV. The purpose of this study is to investigate the role of apoptosis in blister formation in PV.

Methods

This cross‐sectional study was conducted on 25 specimens of oral PV. The presence of apoptosis was evaluated using the TUNEL technique in the normal perilesional region, vesicle area, and acantholytic cells. Also, the expression of Bax pro‐apoptotic marker was assessed by the biotin–streptavidin immunohistochemical method. SPSS software was used for Wilcoxon test analysis. P values <0.05 were considered significant.

Results

The percentage and intensity staining of TUNEL‐positive cells were noteworthy. There were statistically significant differences between basal and parabasal (P = 0.05), tombstone with vesicle roof (P = 0.038) and basal with tombstone (P = 0.038). However, the expression and staining intensity of pro‐apoptotic marker Bax were weak, and no statistically significant differences were observed between the various areas.

Conclusion

The results obtained in the present study suggest that the process of apoptosis occurs early in PV because it was observed in the perilesional normal appearing tissue. Also, the process of apoptosis may cause exacerbation or speeding of the bulla formation. In other words, inhibition of apoptosis in the patients could reduce the severity of the lesions. .
Directed Networks with Spillovers
Authors: BILLAND PASCAL , BRAVARD CHRISTOPHE , SARANGI SUDIPTA
Published: November 2012

We study noncooperative network formation in two types of directed networks. In the first type, called the model with global spillovers, the payoff of a player depends on the number of links she forms as well as the total number of links formed by all other players. In the second type, called the model with local spillovers, the payoff of a player depends on the number of links she forms and the total number of links formed by her immediate neighbors, as well as the number of links formed by players outside her neighborhood. For both classes of games we investigate the existence of pure strategy Nash equilibria and characterize the Nash networks under a number of different second order conditions on the payoff function.
Majority Voting in Multidimensional Policy Spaces: Kramer–Shepsle versus Stackelberg
Authors: DE DONDER PHILIPPE , LE BRETON MICHEL , PELUSO EUGENIO
Published: November 2012

We study majority voting over a bidimensional policy space when the voters’ type space is either uni‐ or bidimensional. We study two voting procedures widely used in the literature. The Stackelberg (ST) procedure assumes that votes are taken one dimension at a time according to an exogenously specified sequence. The Kramer–Shepsle (KS) procedure also assumes that votes are taken separately on each dimension, but not in a sequential way. A vector of policies is a Kramer–Shepsle equilibrium if each component coincides with the majority choice on this dimension given the other components of the vector. We study the existence and uniqueness of the ST and KS equilibria, and we compare them, looking for example at the impact of the ordering of votes for ST and identifying circumstances under which ST and KS equilibria coincide. In the process, we state explicitly the assumptions on the utility function that are needed for these equilibria to be well‐behaved. We especially stress the importance of single‐crossing conditions, and we identify two variants of these assumptions: a marginal version that is imposed on all policy dimensions separately, and a joint version whose definition involves both policy dimensions.
On Welfare Criteria and Optimality in an Endogenous Growth Model
Authors: DEL REY ELENA , LOPEZ‐GARCIA MIGUEL‐ANGEL
Published: November 2012

In this paper, we explore the consequences for optimality of a social planner adopting two different welfare criteria. The framework of analysis is an overlapping generations model with physical and human capital. We first show that, when the social welfare function is a discounted sum of individual utilities defined over consumption per unit of natural labor, the precise cardinalization of the individual utility function becomes crucial for both the characterization of the social optimum and the policies that support it. Also, decentralizing the social optimum requires an education subsidy that is definitely positive, but its size depends in a determinant way on the aforementioned cardinalization. In contrast, when the social welfare function is a discounted sum of individual utilities defined over consumption per unit of efficient labor, the precise cardinalization of preferences becomes irrelevant. More strikingly, along the optimal growth path, the education subsidy is negative, i.e., the planner should tax rather than subsidize investments in human capital.
Inefficient Investment, Information Asymmetry, and Competition for Managers
Authors: SEOG S. HUN , BAIK YOON‐SUK
Published: November 2012

We investigate the possible inefficiency of investment when the manager has better information than the principal. We assume that projects can be grouped into two categories based on their information characteristics of soft and hard information. We consider a case in which the manager faces competition for appointment at the end of term. We consider several cases in which the competitor's ability is known, or proxied by the performance of other managers, or is uncertain. We find that hard information projects are preferred to soft information projects and that the efficiency in project selection critically depends on the competitor's ability. Interestingly, information asymmetry may be socially beneficial, because it can provide the manager with incentives to select high‐quality hard‐information projects. Welfare improvement can be made by a budget change that is in the opposite direction to the optimum. Several empirical implications of the theory are discussed.
Comparison of central venous catheter and peripheral vein samples of antibiotics in children with cystic fibrosis
Authors: Wilson Karen , Jamerson Patricia A.
Published: November 2012

Purpose.

To determine if accurate serum antibiotic levels can be obtained from central venous catheters (CVCs) in pediatric patients with cystic fibrosis.

Design and Methods.

Fifty paired CVC–peripheral vancomycin or tobramycin specimens were collected within 5 min of each other following a 5‐ml flush and discard. Specimen samples were randomized by first site drawn.

Results.

CVC–peripheral antibiotic levels were highly correlated (r =.97, p <.001), with no statistically significant difference (t = 1.18, p =.25). Bland–Altman plot analysis revealed a bias of.47, with limits of agreement ranging from −4.20 to 6.87.

Practice Implications.

Accurate antibiotic concentrations can be obtained from CVCs, reducing pediatric patient trauma and stress.
Evidence‐based asthma education for parents
Authors: Cleveland Kelli K.
Published: November 2012

Purpose.

The purpose of this project was to develop and implement an evidence‐based asthma education brochure for parents of pediatric asthma patients.

Design and Methods.

The asthma patients were 4–12 years old. The number of office sick visits, emergency room visits, and hospitalizations related to asthma were evaluated post‐education, and then compared with the previous months.

Results.

Although there were no statistically significant results, there were notable trends that apply to asthma practice.

Practice Implications.

As a result of the project, there were positive changes noted within the pediatric clinic related to asthma education, and additional suggestions for future opportunities were made.
Elevated Serum Cardiac Troponin I in Cattle with Theileriosis
Authors: Fartashvand M. , Nadalian M.G. , Sakha M. , Safi S.
Published: November 2012

Background

Theileria annulata is a blood parasite affecting ruminants. Hemolytic anemia, secondary hypoxia, and vasculitis are the most important features of tropical theileriosis.

Objectives

Evaluation of electrocardiographic findings and changes in cardiovascular biochemical markers including cTnI concentrations in cattle naturally infected with theileriosis in the absence of acute cardiac failure.

Animals

Ninety adult Holstein cattle (>1 year) with clinical and laboratory evidence of theileriosis and 30 healthy cattle served as controls.

Methods

Case‐control study in which blood samples were collected and randomized after clinical, hematologic, parasitologic examination and laboratory confirmation and electrocardiographic recording on all animals, serum cardiac troponin I (cTnI), aspartate aminotransferase (AST), and creatine kinase‐MB (CK‐MB) were evaluated.

Results

Serum concentration of cTnI was significantly higher in cattle with theileriosis (mean: 0.028 ng/mL; range: 0.005–0.21 ng/mL; control mean: 0.011; range: <0.005–0.09 ng/mL; P = .003). There was significant correlation between serum level of cTnI and PCV (r = −0.257; P < .001) and also between cTnI and parasitemia (r = 0.515; P < .001). Mean serum activities of AST and CK‐MB were 107 ± 46 and 301 ± 103 U/L in sick animals, which were significantly higher than healthy cattle (P = .002 and P = .041, respectively). There were no pathologic arrhythmias detected in sick animals.

Conclusions and Clinical Importance

Theileriosis is a risk factor for elevation of cardiac biomarkers in naturally infected Holstein cattle. Severity of anemia and parasitemia might contribute to the pathophysiology of myocardial damage. The prognostic significance of increased serum cardiac troponin I concentrations in cattle with hemolytic anemia merits further investigation.
Effects of invasion by introduced versus native conifers on coastal heathland vegetation
Authors: Saure Heidi I. , Vandvik Vigdis , Hassel Kristian , Vetaas Ole R.
Published: November 2012

Questions

What are the effects of conifer invasion on plant species composition and richness of coastal heathlands; do effects differ between heathlands invaded by introduced or native coniferous tree species?

Location

Threatened coastal Calluna heathlands, western Norway.

Methods

We compared the effects of invasion by introduced Sitka spruce (Picea sitchensis (Bong.) Carr.) and native Scots pine (Pinus sylvestris L.) on heathland plant communities by focusing on the local impacts of single coniferous tree canopies. For each of 58 target coniferous trees (2–4‐m tall), 2‐m transects were laid out in a north and south orientation from the tree stem to beyond the tree canopy, and control transects were laid out in open heathland adjacent to the target trees. Vascular plants and bryophytes were recorded within 0.0625 m2 contiguous quadrats along the transects. Principal response curves (PRC) and generalized linear mixed models (GLMMs) were used to investigate tree canopy effects on species composition and richness.

Results

Invasion by coniferous trees induced considerable changes in the coastal heathland vegetation: distinct microcommunitites developed beneath the canopies of relatively young, single coniferous trees in the heathlands. There was a marked difference in subcanopy species composition under the introduced Sitka spruce relative to the native Scots pine; forest floor species had colonized to a greater extent under Sitka spruce, replacing the light‐demanding species characteristic of the coastal heathland vegetation.

Conclusion

Our study showed that conifer invasion induces considerable and rapid changes in heathland vegetation, and that the effects were stronger under the introduced conifer. This suggests that Sitka spruce invasion may pose a more immediate threat to the characteristic coastal heathland vegetation and flora than succession based on native conifers. The open coastal heathlands along the Atlantic coast of Western Europe are a threatened landscape of high conservation value, and our results suggest that the spread of Sitka spruce into these landscapes should be controlled, especially in heathlands that are targeted for conservation.
Intercellular and intracellular signalling systems that globally control the expression of virulence genes in plant pathogenic bacteria
Authors: Ham Jong Hyun
Published: November 2012

Plant pathogenic bacteria utilize complex signalling systems to control the expression of virulence genes at the cellular level and within populations. Quorum sensing (QS), an important intercellular communication mechanism, is mediated by different types of small molecules, includingN‐acyl homoserine lactones (AHLs), fatty acids and small proteins.AHL‐mediated signalling systems dependent on theLuxIandLuxRfamily proteins play critical roles in the virulence of a wide range ofGram‐negative plant pathogenic bacteria belonging to theAlphaproteobacteria,Betaproteobacteria andGammaproteobacteria.Xanthomonasspp. andXylella fastidiosa, members of theGammaproteobacteria, however, possessQSsystems that are mediated by fatty acid‐type diffusible signal factors (DSFs). Recent studies have demonstrated thatAx21, a 194‐amino‐acid protein inXanthomonas oryzaepv.oryzae, plays dual functions in activating a rice innate immune pathway through binding to the riceXA21pattern recognition receptor and in regulating bacterial virulence and biofilm formation as aQSsignal molecule. In xanthomonads,DSF‐mediatedQSsystems are connected with the signalling pathways mediated by cyclic diguanosine monophosphate (c‐di‐GMP), which functions as a second messenger for the control of virulence gene expression in these bacterial pathogens.
The microbiome is essential for normal gut intrinsic primary afferent neuron excitability in the mouse
Authors: McVey Neufeld K. A. , Mao Y. K. , Bienenstock J. , Foster J. A. , Kunze W. A.
Published: November 2012

Background  The role of intestinal microbiota in the development and function of host physiology is of high interest, especially with respect to the nervous system. While strong evidence has accrued that intestinal bacteria alter host nervous system function, mechanisms by which this occurs have remained elusive. For this reason, we have carried out experiments examining the electrophysiological properties of neurons in the myenteric plexus of the enteric nervous system (ENS) in germ‐free (GF) mice compared with specific pathogen‐free (SPF) control mice and adult germ‐free mice that have been conventionalized (CONV‐GF) with intestinal bacteria.

Methods  Segments of jejunum from 8 to 12 week old GF, SPF, and CONV‐GF mice were dissected to expose the myenteric plexus. Intracellular recordings in current‐clamp mode were made by impaling cells with sharp microelectrodes. Action potential (AP) shapes, firing thresholds, the number of APs fired at 2× threshold, and passive membrane characteristics were measured.

Key Results  In GF mice, excitability was decreased in myenteric afterhyperpolarization (AH) neurons as measured by a lower resting membrane potential and by the number of APs generated at 2× threshold. The post AP slow afterhyperpolarization (sAHP) was prolonged for GF compared with SPF and CONV‐GF animals. Passive membrane characteristics were also altered in GF mice by a decrease in input resistance.

Conclusions & Inferences  Here, we report the novel finding that commensal intestinal microbiota are necessary for normal excitability of gut sensory neurons and thus provide a potential mechanism for the transfer of information between the microbiota and nervous system.
HIV diagnosis and testing: what every healthcare professional can do (and why they should)
Authors: Wilson E , Tanzosh T , Maldarelli F
Published: November 2012

Over the last thirty years, the human immunodeficiency virus (HIV) epidemic has matured. In the United States, HIV has changed from an explosive outbreak to an endemic disease; currently, an estimated 1.1 million people are infected with HIV, including a substantial number who are unaware of their status. With recent findings demonstrating the high transmissibility of HIV early in infection, and the potential benefit of early initiation of treatment, it is essential to identify as many infected individuals as possible. The Centers for Disease Control and Prevention (CDC) has expanded HIV testing to include any healthcare setting, including dental offices. Testing advances, including oral testing, have reduced the window period of HIV infection. Dental care represents a key, reliable, independent, and confidential link between the healthcare system and the general population that has been under‐utilized in the effort to control the HIV epidemic. HIV testing is straightforward, and knowledge of the types of testing will afford dentists an important opportunity to help advance and preserve the health of their patients and to promote the public health of their community. Here, we review the basics of HIV testing and discuss new changes in the approach to HIV diagnostics.
Fortifying plants with the essential amino acids lysine and methionine to improve nutritional quality
Authors: Galili Gad , Amir Rachel
Published: November 2012

Humans, as well as farm animals, cannot synthesize a number of essential amino acids, which are critical for their survival. Hence, these organisms must obtain these essential amino acids from their diets. Cereal and legume crops, which represent the major food and feed sources for humans and livestock worldwide, possess limiting levels of some of these essential amino acids, particularly Lys and Met. Extensive efforts were made to fortify crop plants with these essential amino acids using traditional breeding and mutagenesis. However, aside from some results obtained with maize, none of these approaches was successful. Therefore, additional efforts using genetic engineering approaches concentrated on increasing the synthesis and reducing the catabolism of these essential amino acids and also on the expression of recombinant proteins enriched in them. In the present review, we discuss the basic biological aspects associated with the synthesis and accumulation of these amino acids in plants and also describe recent developments associated with the fortification of crop plants with essential amino acids by genetic engineering approaches.
Which covariates should be controlled in propensity score matching? Evidence from a simulation study
Authors: Cuong Nguyen Viet
Published: November 2012

Propensity score matching is a widely‐used method to measure the effect of a treatment in social as well as medicine sciences. An important issue in propensity score matching is how to select conditioning variables in estimation of the propensity scores. It is commonly mentioned that variables which affect both program participation and outcomes are selected. Using Monte Carlo simulation, this paper shows that efficiency in estimation of the Average Treatment Effect on the Treated can be gained if all the available observed variables in the outcome equation are included in the estimation of propensity scores. This result still holds in the presence of non‐sampling errors in the observed control variables.
Comparative ocular anatomy in a blind African cichlid fish, Lamprologus lethops
Authors: Schobert Charles S. , Stiassny Melanie L. J. , Schwab Ivan R. , Zeiss Caroline , Schelly Robert C. , Dubielzig Richard R.
Published: November 2012

Objective

Troglomorphic fishes provide excellent comparative models for studying eye evolution. We describe the gross and microscopic anatomy of ocular structures of the depigmented, blind cichlid, Lamprologus lethops, and its putative sister species, Lamprologus tigripictilis collected from the lower Congo River in the Democratic Republic of Congo.

Procedures

Both species were fixed, paraffin‐sectioned and stained. Immunohistochemical staining for rhodopsin markers was also performed.

Results

The globe in L. lethops is smaller than its sighted congener and recessed beneath bone and skin. The scleral profile maintains a wrinkled spherical shape, and the choroid is occupied by adipose tissue containing no rete mirabilis. The globe in L. lethops is foreshortened in the anterior–posterior dimension and deviated dorsally toward the midline with no extraocular muscles. At the posterior pole of the globe, there is an open periocular space containing no cell bodies. In L. tigripictilis, no choroidal adipose tissue is seen and a rete mirabilis is present. The retina of L. lethops is thinner compared with L. tigripictilis. Both species have scleral cartilage and fully developed lenses. Rhodopsin is present in the inner and outer segments of both species.

Conclusions

Ocular adaptations evolve over time as a response to a life in darkness. Combining ocular anatomy, developmental data, and genetics will lead to insights about evolution in these fishes and contribute to understanding how ocular evolution works in other vertebrates.
Lateral hypothalamic GAD65 neurons are spontaneously firing and distinct from orexin‐ and melanin‐concentrating hormone neurons
Authors: Karnani Mahesh M. , Szabó Gábor , Erdélyi Ferenc , Burdakov Denis
Published: November 2012

Key points

Lateral hypothalamus (LH) contains GABA neurons involved in controlling metabolism and sleep.

LH glutamic acid decarboxylase 65 (GAD65) GABA neurons are intrinsically depolarized, unlike classical GAD65 neurons of the cortex.

LH GAD65 GABA neurons are distinct from most studied LH neurons (orexin and melanin‐concentrating hormone cells).

A subset of LH GAD65 neurons are glucose inhibited.

Our study adds new populations of glucose sensing neurons to the list of hypothalamic sugar sensors and introduces inhibitory circuit elements of the LH.

Abstract  GABAergic neurons are vital for brain function. Their neurochemical and electrical features have been classically characterized in the cortex, but in the lateral hypothalamic area (LHA), such knowledge is lacking, despite the emerging roles of LHA GABAergic cells in feeding and sleep. We used GAD65‐GFP transgenic mice, developed for studies of cortical GABAergic cells, to determine fundamental properties of LHA GAD65 neurons, and compare them to ‘classical’ GABAergic cell types of the cortex, and to previously described classes of LHA cells. Whole‐cell patch‐clamp recordings in acute brain slices revealed that, unlike cortical GABAergic interneurons, LHA GAD65 neurons were intrinsically depolarized and fired action potentials spontaneously. Similar to cortical GABAergic cells, LHA GAD65 cells fell into four major subtypes based on evoked firing: fast spiking, late spiking, low threshold spiking and regular spiking. Three‐dimensional reconstructions of biocytin‐filled neurons, performed after the patch‐clamp analysis, did not reveal striking morphological differences between these electrophysiological subtypes. Peptide transmitters expressed in known classes of LHA projection neurons, namely melanin‐concentrating hormone (MCH) and hypocretin/orexin (hcrt/orx), were not detected in LHA GAD65 cells. Approximately 40% of LHA GAD65 cells were directly inhibited by physiological increases in extracellular glucose concentration. Glucose inhibition was most prevalent in the fast spiking subpopulation, although some glucose‐responsive neurons were found in each electrophysiological subpopulation. These results suggest that LHA GAD65 neurons are electrically different from ‘classical’ GABAergic neurons of the cortex, are neurochemically distinct from LHA hcrt/orx and MCH cells, but partly resemble hcrt/orx cells in their glucose responses.
Inhibition of dendritic Ca2+ spikes by GABAB receptors in cortical pyramidal neurons is mediated by a direct Gi/o‐βγ‐subunit interaction with Cav1 channels
Authors: Pérez‐Garci Enrique , Larkum Matthew E. , Nevian Thomas
Published: November 2012

Key points

Voltage‐dependent Ca2+ channels mediate a large repertoire of physiological actions, including the generation of dendritic spikes in neocortical pyramidal neurons; however, the type of Ca2+ channels involved in their generation remains unknown.

We found that L‐type Ca2+ currents generate the sustained plateau potential of the Ca2+ spike. GABAB receptors inhibit Ca2+ spikes by specifically blocking dendritic L‐type currents.

This inhibition is mediated by a direct Gi/o‐βγ‐subunit interaction with the Cav1 channels.

Protein kinases (protein kinase C and A) have an important influence on the generation and sustaining of dendritic Ca2+ spikes; however, their activity is not involved in the GABAB‐mediated inhibition of Ca2+ spikes.

Inhibitory modulation of dendritic activity is important to understand the transformation of synaptic inputs into neuronal output activity. Our results shed light on the molecular mechanisms by which GABA acting via its GABAB receptors can exert this inhibitory action.

Abstract  Voltage‐dependent calcium channels (VDCCs) serve a wide range of physiological functions and their activity is modulated by different neurotransmitter systems. GABAergic inhibition of VDCCs in neurons has an important impact in controlling transmitter release, neuronal plasticity, gene expression and neuronal excitability. We investigated the molecular signalling mechanisms by which GABAB receptors inhibit calcium‐mediated electrogenesis (Ca2+ spikes) in the distal apical dendrite of cortical layer 5 pyramidal neurons. Ca2+ spikes are the basis of coincidence detection and signal amplification of distal tuft synaptic inputs characteristic for the computational function of cortical pyramidal neurons. By combining dendritic whole‐cell recordings with two‐photon fluorescence Ca2+ imaging we found that all subtypes of VDCCs were present in the Ca2+ spike initiation zone, but that they contribute differently to the initiation and sustaining of dendritic Ca2+ spikes. Particularly, Cav1 VDCCs are the most abundant VDCC present in this dendritic compartment and they generated the sustained plateau potential characteristic for the Ca2+ spike. Activation of GABAB receptors specifically inhibited Cav1 channels. This inhibition of L‐type Ca2+ currents was transiently relieved by strong depolarization but did not depend on protein kinase activity. Therefore, our findings suggest a novel membrane‐delimited interaction of the Gi/o‐βγ‐subunit with Cav1 channels identifying this mechanism as the general pathway of GABAB receptor‐mediated inhibition of VDCCs. Furthermore, the characterization of the contribution of the different VDCCs to the generation of the Ca2+ spike provides new insights into the molecular mechanism of dendritic computation.
Characterizing the Effects of Learning When Reverse Engineering Multiple Samples of the Same Product
Authors: Curtis Shane K. , Harston Stephen P. , Mattson Christopher A.
Published: November 2012

Reverse engineering is the process of extracting information about a product from the product itself. An estimate of the barrier and time to extract information from any product is useful for the original designer and those reverse engineering, as both are affected by reverse engineering activities. The authors have previously presented a set of metrics and parameters to estimate the barrier and time to reverse engineer a product once. This work has laid the foundation for the developments of the current paper, which address the issue of characterizing the reverse engineering time and barrier when multiple samples of the same product are reverse engineered. Frequently in practice, several samples of the same product are reverse engineered to increase accuracy, extract tolerances, or to gather additional information from the product. In this paper, we introduce metrics that (i) characterize learning in the reverse engineering process as additional product samples are evaluated and (ii) estimate the total time to reverse engineer multiple samples of the same product. Additionally, an example of reverse engineering parts from a control valve is introduced to illustrate how to use the newly developed metrics and to serve as empirical validation.
A Metric to Evaluate and Synthesize Distributed Compliant Mechanisms
Authors: Krishnan Girish , Kim Charles , Kota Sridhar
Published: November 2012

Compliant mechanisms with evenly distributed stresses have better load-bearing ability and larger range of motion than mechanisms with compliance and stresses lumped at flexural hinges. In this paper, we present a metric to quantify how uniformly the strain energy of deformation and thus the stresses are distributed throughout the mechanism topology. The resulting metric is used to optimize cross-sections of conceptual compliant topologies leading to designs with maximal stress distribution. This optimization framework is demonstrated for both single-port mechanisms and single-input single-output mechanisms. It is observed that the optimized designs have lower stresses than their nonoptimized counterparts, which implies an ability for single-port mechanisms to store larger strain energy, and single-input single-output mechanisms to perform larger output work before failure.