bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification and differentiation of the genus Peganum indigenous to China based on chloroplast trnL‐F and psbA‐trnH sequences and seed coat morphology
Authors: Zhao T. , Wang Z.‐T. , Branford‐White C. J. , Xu H. , Wang C.‐H.
Published: March 2011

The genus Peganum (Zygophyllaceae) consists of six species and one subspecies; three of which are distributed in China, P. harmala Linn, P. nigellastrum Bunge and P. multisectum (Maxim.) Bobr. A probable new or intermediate species, Peganum sp., has been suggested in the wild in northwest China. Traditional classification in genus Peganum has focused on hairs on the plant surface. In this study, seed coat characteristics of Peganum species were investigated using light and scanning electron microscopy, demonstrating clear differences in morphology between species. In addition, DNA sequence data from two sequences (chloroplast: trnL‐F, psbA‐trnH) were used to differentiate Peganum sp. and study polygenetic relationships. Diversity in DNA sequences among Peganum species was found, with inter‐specific sequence divergence ranging from 0.6% to 5.6% in psbA‐trnH, and 0.0% to 1.8% in trnL‐F. The variations within species were low: from 0.0% to 0.4% in psbA‐trnH and 0.0% to 0.4% in trnL‐F. Therefore, Peganum species can now be easily identified as separate entities based on variations in DNA sequences. Phylogenetic trees were constructed from the combined data set for the two gene fragments, and the results indicate that Peganum sp. is monophyletic and sister to P. harmala and P. nigellastrum, while P. multisectum is also monophyletic. DNA data further confirmed that P. multisectum is an independent species and that a new species, Peganum sp., exists within the genus Peganum growing wild in China.
Effect of topical 0.03% flurbiprofen and 0.005% latanoprost, alone and in combination, on normal canine eyes
Authors: Pirie Chris G. , Maranda Louise S. , Pizzirani Stefano
Published: March 2011

Objective Evaluate the influence of topically applied flurbiprofen 0.03% and latanoprost 0.005%, alone or in combination, in normal canines.

Animals studied 10 Normal Beagles.

Procedures Intraocular pressure (IOP), pupil size, aqueous flare, conjunctival hyperemia, and blepharospasm were evaluated bilaterally five times daily (8 am, 11 am, 2 pm, 5 pm,and 8 pm). The study consisted of a training and acclimation period, followed by 3, 1‐week experiment periods. A 2‐week washout period occurred between each experiment period. During period 1, all dogs received flurbiprofen (three doses 6‐h apart) in the treated eye, whereas in period 2, all dogs received latanoprost (one dose 24‐h apart). During period 3, both latanoprost (one dose 24‐h apart) and flurbiprofen (three doses 6‐h apart) were administered in the treated eye.

Results Flurbiprofen resulted in a mean IOP elevation of 1.1 mmHg (8.65%) in the treated eye, as compared with the control eye. No effect on pupil size, conjunctival hyperemia, or aqueous flare was noted. Latanoprost resulted in a mean IOP reduction of 3.4 mmHg (30.19%). Combined latanoprost and flurbiprofen resulted in a mean IOP reduction of 2.7 mmHg (24.56%). Miosis was noted in the treated eyes during both latanoprost periods, with maximal pupil constriction 3‐h post‐dose. This was followed by relative mydriasis 24‐h post‐dose, persisting 48 h after the last dose. The degree of conjunctival hyperemia varied between individuals. Neither blepharospasm nor aqueous flare was noted at any time point.

Conclusion Concurrent administration of latanoprost and flurbiprofen resulted in a 20.41% reduction in the ocular hypotensive effect relative to latanoprost therapy alone.
Ultrasound findings in horses with severe eyelid swelling, and recognition of acute dacryoadenitis: 10 cases (2004–2010)
Authors: Reimer Johanna M. , Latimer Claire S.
Published: March 2011

Objective  To report the sonographic findings, treatment, and outcome of horses with severe eyelid swelling, to describe the sonographic appearance of enlarged lacrimal glands, and to describe the clinical features of acute dacryoadenitis.

Materials and methods  Medical records of all horses with severe eyelid swelling that underwent an ultrasound evaluation of the globe and periorbital structures from 2004–2010 were examined. Cases were limited to those in which the eyelid swelling was so severe that the globe could not be visualized.

Results  Ten horses met the criteria for inclusion in the study. All cases were unilateral and acute. Marked enlargement of the lacrimal gland was found in five cases, and supported the diagnosis of acute dacryoadenitis. Eyelid abscessation was found in three horses, accompanied by mild to moderate lacrimal gland enlargement in two of the three. Enlarged lacrimal glands were slightly heterogeneous in appearance and could be differentiated from an abscess by imaging the protrusion of the gland from beneath the supraorbital rim. Only two cases of severe eyelid swelling were soley traumatic.

Conclusions  Severe eyelid swelling was often associated with dacryoadenitis and/or eyelid abscessation. The detection of marked lacrimal gland enlargement in horses with an acute onset of severe painful eyelid swelling is consistent with a diagnosis of acute dacryoadenitis. Ultrasonographic evaluation of eyelid swelling of any degree is warranted to determine if enlargement of the lacrimal gland, etiology notwithstanding, is an underlying or contributing cause.
The impact of overactive bladder on mental health, work productivity and health‐related quality of life in the UK and Sweden: results from EpiLUTS
Authors: Coyne Karin S. , Sexton Chris C. , Kopp Zoe S. , Ebel‐Bitoun Caty , Milsom Ian , Chapple Chris
Published: March 2011

Study Type – Symptom prevalence (prospective cohort)

Level of Evidence 1b

OBJECTIVE

• To examine the prevalence and burden of overactive bladder (OAB) with bother in the UK and Sweden compared to OAB without bother and no/minimal OAB/lower urinary tract (LUTS) symptoms, respectively.

PATIENTS AND METHODS

• A cross‐sectional population‐representative survey was conducted via the Internet in the UK, Sweden and USA.

• Participants rated the frequency and bother of OAB and LUTS. Patient outcomes included the Overactive Bladder Questionnaire Short Form, Patient Perception of Bladder Condition, Short Form‐12, Hospital Anxiety and Depression Scale–Anxiety and Hospital Anxiety and Depression Scale–Depression, as well as questions about treatment seeking and work productivity.

• OAB was defined as urgency at least sometimes or the presence of urinary urgency incontinence. Three subgroups were compared: no/minimal symptoms, OAB without bother and OAB with bother.

• Analyses were conducted by gender and country using general linear and logistic regression models to examine bothersome OAB and treatment seeking.

RESULTS

• Survey response was 59.2%; 10 000 people (4724 men and 5276 women) participated.

• The prevalence of OAB with bother at least ‘somewhat’ was 10.9% and 14.6% for men in the UK and Sweden, and 22.5% and 33.7% for women in the UK and Sweden, respectively.

• Men and women with bothersome OAB were significantly more likely to seek treatment, report the lowest levels of health‐related quality of life and work productivity and the highest levels of anxiety and depression compared to those with no/minimal symptoms and OAB without bother.

• Greater symptom severity of urgency, urgency urinary incontinence, frequency, nocturia, and increasing levels of anxiety were strongly predictive of OAB bother in both men and women.

• Predictors of treatment seeking included frequency, bother as a result of urgency, and lower levels of depressive symptoms in men, and frequency, nocturia and urgency in women.

CONCLUSIONS

• OAB is common in the UK and Sweden, and women are more likely to be affected then men.

• The impact of OAB is evident across generic and condition‐specific domains of health‐related quality of life.
Can simvastatin improve erectile function and health‐related quality of life in men aged >40 years with erectile dysfunction? Rationale and design of the Erectile Dysfunction and Statins (EDS) Trial [ISRCTN66772971]1
Authors: Trivedi Daksha , Kirby Michael , Norman Felicity , Przybytniak Izabela , Ali Shehzad , Wellsted David M.
Published: March 2011

What’s known on the subject? and What will the study add?

Erectile dysfunction is often associated with endothelial dysfunction. It is also recognized as a marker for underlying vascular disease.

This study tests the hypothesis that statin therapy may improve erectile function and also reduce the risk of future cardiovascular events via a reduction in serum cholesterol and by improving endothelial function. The study will also determine whether the treatment improves quality of life related to sexual function.

OBJECTIVE

• To describe the rationale and design of the Erectile Dysfunction and Statins (EDS) Trial which aims to evaluate the effectiveness of simvastatin on erectile function and health‐related quality of life in men aged ≥40 years with erectile dysfunction.

PATIENTS AND METHODS

• The study is a randomized, double‐blind, placebo‐controlled trial to test the hypotheses that statins improve endothelial function and reduce cholesterol and may improve erectile function in men with untreated erectile dysfunction (ED).

• Study subjects are men ≥40 years who are not receiving lipid‐lowering or anti‐hypertensive medication and have no other cardiovascular disease (CVD) risk factors.

• Eligible men with untreated ED are randomized to double‐blind treatment with 40 mg simvastatin or placebo once daily for 6 months.

• Data are collected at baseline, mid‐trial and at the final follow‐up visit at 30 weeks.

• The main outcome is erectile function measured by the five‐item version of the International Index of Erectile Function. Secondary outcomes include sexual‐health‐related quality of life and endothelial function.

RESULTS

• Ten general practices have been recruited in the east of England.

• We have randomized 173 men for a power of 90% to assess the main outcome.

• To date there have been no serious unexpected adverse events.

• Study findings will be available in September 2011.

CONCLUSION

• If simvastatin improves erectile function it would provide an inexpensive treatment for ED suitable for most men, and reduce the risk of future CVD.
On the Determinants of Optimism in Financial Analyst Earnings Forecasts: The Effect of the Market's Ability to Adjust for the Bias
Authors: KARAMANOU IRENE
Published: March 2011

This paper examines whether the documented bias in analyst earnings forecasts is intentional by examining whether it is related to the market's ability to adjust for this bias. For intentional bias to exist it is not enough for analysts to face incentives but rather, analysts should also be willing to respond to these incentives. As the market's ability to adjust for the bias increases, its market effects decrease while analyst reputation costs increase reducing analyst willingness to bias their forecasts. The paper utilizes a firm‐specific design that allows for both the bias component of the forecast error and the market's ability to adjust for the bias to be computed at the firm level. Results suggest that even though forecast error is positive in the latter part of the period under review reflecting overall analyst pessimism, the bias embedded in the forecasts is optimistic throughout the period. More importantly, I find that analyst forecast bias is decreasing in the market's ability to adjust for it. This result provides further evidence that analysts knowingly bias their forecasts and provides support for the existence of reporting bias, in particular. Thus, the evidence provides justification for recent regulatory efforts to increase the objectivity of analyst research reports.
Assessing the Impact of Fair‐Value Accounting on Financial Statement Analysis: A Data Envelopment Analysis Approach
Authors: RODRÍGUEZ‐PÉREZ GONZALO , SLOF JOHN , SOLÀ MAGDA , TORRENT MARGARITA , VILARDELL IMMACULADA
Published: March 2011

The historical‐cost and prudence principles have guided accounting for financial investments and tangible fixed assets in many jurisdictions around the globe. This situation might change as a consequence of the increasing number of countries adopting International Financial Reporting Standards (IFRS), which, to some extent, permit accounting on a fair‐value basis. It is unclear how such a change would affect the analysis of financial statements and to what extent it could modify analysts' perceptions of companies' condition and performance. This paper attempts to shed some light on this issue by restating the financial investments and tangible fixed assets of a sample of 85 Spanish insurance companies, applying fair value instead of historical‐cost‐based valuations and by simulating analyst perception of these companies' efficiency and profitability for both sets of data using data envelopment analysis (DEA). We find that the numbers on the face of the financial statements change considerably and observe that the magnitude of these changes varies between companies and classes of assets. However, only in a few cases does a change in the valuation basis lead to a relevant change in DEA scores; within our sample, the overall assessment of companies with regard to efficiency and profitability remains largely the same under both valuation bases. These findings seem to indicate that a change from historical‐cost to fair‐value accounting could alter analyst perceptions of a limited number of companies but likely will not have a major impact on the appraisal of the majority of them.
The Detection and Dynamics of Financial Distress*
Authors: FITZPATRICK JULIE , OGDEN JOSEPH P.
Published: March 2011

Using samples of US firms, we examine the efficacy of six risk‐proxy variables to forecast 5‐year failure: year‐end t‐values of stock return volatility, firm size, recent profitability, market leverage (LEV), book‐to‐market equity ratio (BM), and recent stock return. Logistic regression results indicate that firm size is most powerful, while LEV and BM are weakest. We then identify distressed firms and analyze the effect of year t+1 operating and financing cash flows on 5‐year failure rates for these firms using a new methodology, failure risk surprise. Results explain why LEV and BM are weak forecasters of 5‐year failure rates: Low‐LEV and low‐BM (high‐LEV and high‐BM) distressed firms are less (more) likely to have a profit in year t+1, and are also more likely to issue equity (retire debt) in year t+1, interactions which tend to moderate failure risk. We also find that failure risk sensitivity to year t+1 operating result increases with both LEV and BM, while failure risk sensitivity to future macroeconomic conditions is significant only for high‐LEV firms. Many results are consistent with the tradeoff theory of capital structure, while other results indicate that managers make financing decisions to take advantage of mispricing.
Pathways to meiotic recombination in Arabidopsis thaliana
Authors: Osman Kim , Higgins James D. , Sanchez‐Moran Eugenio , Armstrong Susan J. , Franklin F. Chris H.
Published: March 2011

Meiosis is a central feature of sexual reproduction. Studies in plants have made and continue to make an important contribution to fundamental research aimed at the understanding of this complex process. Moreover, homologous recombination during meiosis provides the basis for plant breeders to create new varieties of crops. The increasing global demand for food, combined with the challenges from climate change, will require sustained efforts in crop improvement. An understanding of the factors that control meiotic recombination has the potential to make an important contribution to this challenge by providing the breeder with the means to make fuller use of the genetic variability that is available within crop species. Cytogenetic studies in plants have provided considerable insights into chromosome organization and behaviour during meiosis. More recently, studies, predominantly in Arabidopsis thaliana, are providing important insights into the genes and proteins that are required for crossover formation during plant meiosis. As a result, substantial progress in the understanding of the molecular mechanisms that underpin meiosis in plants has begun to emerge. This article summarizes current progress in the understanding of meiotic recombination and its control in Arabidopsis. We also assess the relationship between meiotic recombination in Arabidopsis and other eukaryotes, highlighting areas of close similarity and apparent differences.

Contents

Summary
523

I.
Introduction
524

II.
The meiotic pathway: a brief overview
524

III.
Homologous chromosome pairing and  movement during prophase I
525

IV.
Meiotic DNA double‐strand break formation
526

V.
Processing of DNA double‐strand breaks
528

VI.
Strand exchange: the role of the RecA  homologues and their accessory proteins
529

VII.
Promotion of stable strand exchange
532

VIII.
Pathways to crossover formation
532

IX.
The class I pathway of meiotic recombination
533

X.
The class II pathway of meiotic recombination
536

XI.
Holliday junction (Hj) resolution
537

XII.
Noncrossover pathways and the crossover/ noncrossover decision
537

XIII.
Conclusions
538

Acknowledgements
538

References
538
Impulsivity in adolescent bipolar disorder
Authors: Gilbert Kirsten E. , Kalmar Jessica H. , Womer Fay Y. , Markovich Philip J. , Pittman Brian , Nolen-Hoeksema Susan , Blumberg Hilary P.
Published: March 2011

Objective: Increased impulsivity has been shown to be a trait feature of adults with bipolar disorder (BD), yet impulsivity has received little study in adolescents with BD. Thus, it is unknown whether it is a trait feature that is present early in the course of the disorder. We tested the hypotheses that self-reported impulsiveness is increased in adolescents with BD, and that it is present during euthymia, supporting impulsiveness as an early trait feature of the disorder.

Methods: Impulsiveness was assessed in 23 adolescents with BD and 23 healthy comparison (HC) adolescents using the self-report measure of impulsivity, the Barratt Impulsiveness Scale (BIS), comprised by attentional, motor and non-planning subscale scores. Effects of subscale scores and associations of scores with mood state and course features were explored.

Results: Total and subscale BIS scores were significantly higher in adolescents with BD than HC adolescents. Total, attentional and motor subscale BIS scores were also significantly higher in the subset of adolescents with BD who were euthymic, compared to HC adolescents. Adolescents with BD with rapid-cycling and chronic mood symptoms had significantly higher total and motor subscale BIS scores than adolescents with BD without these course features.

Conclusion: These results suggest increased self-reported impulsiveness is a trait feature of adolescents with BD. Elevated impulsivity may be especially prominent in adolescents with rapid-cycling and chronic symptoms.
Pathogenesis of Mycosis fungoides
Authors: Beyer Marc , Möbs Markus , Humme Daniel , Sterry Wolfram
Published: March 2011

Mycosis fungoides is the most common type of primary cutaneous lymphomas. The phenotype of the tumor cell corresponds to an effector/memory‐type of helper T cell which, given its repertoire of homing receptors, is specialized for recirculation through the skin. In recent years genetic analyses have uncovered various chromosomal aberrations in the tumour cells of mycosis fungoides. Their relevance to the pathogenesis and clinical appearance are discussed in the following.
Dietary lipids from an evolutionary perspective: sources, structures and functions
Authors: German J. Bruce
Published: March 2011

Lipids are a complex group of biomolecules whose precise functions remain poorly understood. As a result of this poor understanding, it is difficult to make mechanistically based recommendations for appropriate dietary intakes. It is equally difficult to develop methods that are capable of diagnosing functional impairments because of insufficiencies or excesses in particular fatty acids. Lipids are abundant building blocks of cellular membranes, supply components for lipid particle assembly and substrates for metabolic fuel, and provide a precursor pool for an astonishingly diverse range of signalling molecules. In each of these broad functions, the functional consequences of different structures of fatty acids are not fully understood. According to research on membrane functions through early evolution, docosahexaenoic acid provides two biophysical properties to membranes – accelerating the lateral motion of lipids and proteins within the plane of the membrane and simultaneously slowing the rate of diffusion/leakage of charged species across the plane of the membrane. The range of fatty acid structures used as substrates for assembly of either lipoproteins or milk fat globules is broad, yet the functional consequences of differences are not known. Different lipids signal into a remarkable range of biological processes. Saturated and monounsaturated fatty acids are becoming recognized as signal molecules in their own right. The complex composition of human milk lipids implies that diets with a diversity of fatty acids in complex lipid forms and structures is more beneficial than a narrow range of any particular group of fatty acids.
The functional genomics of guanylyl cyclase/natriuretic peptide receptor‐A: Perspectives and paradigms
Authors: Pandey Kailash N.
Published: March 2011

The cardiac hormones atrial natriuretic peptide and B‐type natriuretic peptide (brain natriuretic peptide) activate guanylyl cyclase (GC)‐A/natriuretic peptide receptor‐A (NPRA) and produce the second messenger cGMP. GC‐A/NPRA is a member of the growing family of GC receptors. The recent biochemical, molecular and genomic studies on GC‐A/NPRA have provided important insights into the regulation and functional activity of this receptor protein, with a particular emphasis on cardiac and renal protective roles in hypertension and cardiovascular disease states. The progress in this field of research has significantly strengthened and advanced our knowledge about the critical roles of Npr1 (coding for GC‐A/NPRA) in the control of fluid volume, blood pressure, cardiac remodeling, and other physiological functions and pathological states. Overall, this review attempts to provide insights and to delineate the current concepts in the field of functional genomics and signaling of GC‐A/NPRA in hypertension and cardiovascular disease states at the molecular level.
Structure, signaling mechanism and regulation of the natriuretic peptide receptor guanylate cyclase
Authors: Misono Kunio S. , Philo John S. , Arakawa Tsutomu , Ogata Craig M. , Qiu Yue , Ogawa Haruo , Young Howard S.
Published: March 2011

Atrial natriuretic peptide (ANP) and the homologous B‐type natriuretic peptide are cardiac hormones that dilate blood vessels and stimulate natriuresis and diuresis, thereby lowering blood pressure and blood volume. ANP and B‐type natriuretic peptide counterbalance the actions of the renin–angiotensin–aldosterone and neurohormonal systems, and play a central role in cardiovascular regulation. These activities are mediated by natriuretic peptide receptor‐A (NPRA), a single transmembrane segment, guanylyl cyclase (GC)‐linked receptor that occurs as a homodimer. Here, we present an overview of the structure, possible chloride‐mediated regulation and signaling mechanism of NPRA and other receptor GCs. Earlier, we determined the crystal structures of the NPRA extracellular domain with and without bound ANP. Their structural comparison has revealed a novel ANP‐induced rotation mechanism occurring in the juxtamembrane region that apparently triggers transmembrane signal transduction. More recently, the crystal structures of the dimerized catalytic domain of green algae GC Cyg12 and that of cyanobacterium GC Cya2 have been reported. These structures closely resemble that of the adenylyl cyclase catalytic domain, consisting of a C1 and C2 subdomain heterodimer. Adenylyl cyclase is activated by binding of Gsα to C2 and the ensuing 7° rotation of C1 around an axis parallel to the central cleft, thereby inducing the heterodimer to adopt a catalytically active conformation. We speculate that, in NPRA, the ANP‐induced rotation of the juxtamembrane domains, transmitted across the transmembrane helices, may induce a similar rotation in each of the dimerized GC catalytic domains, leading to the stimulation of the GC catalytic activity.
Inner Speech: Nature and Functions
Authors: Vicente Agustin , Martinez Manrique Fernando
Published: March 2011

We very often discover ourselves engaged in inner speech. It seems that this kind of silent, private, speech fulfils some role in our cognition, most probably related to conscious thinking. Yet, the study of inner speech has been neglected by philosophy and psychology alike for many years. However, things seem to have changed in the last two decades. Here we review some of the most influential accounts about the phenomenology and the functions of inner speech, as well as the methodological problems that affect its study.
Arguments by Leibniz’s Law in Metaphysics
Authors: Magidor Ofra
Published: March 2011

Leibniz’s Law (or as it sometimes called, ‘the Indiscerniblity of Identicals’) is a widely accepted principle governing the notion of numerical identity. The principle states that if a is identical to b, then any property had by a is also had by b. Leibniz’s Law may seem like a trivial principle, but its apparent consequences are far from trivial. The law has been utilised in a wide range of arguments in metaphysics, many leading to substantive and controversial conclusions. This article discusses the applications of Leibniz’s Law to arguments in metaphysics. It begins by presenting a variety of central arguments in metaphysics which appeal to the law. The article then proceeds to discuss a range of strategies that can be drawn upon in resisting an argument by Leibniz’s Law. These strategies divide into three categories: (i) denying Leibniz’s Law; (ii) denying that the argument in question involves a genuine application of the law; and (iii) denying that the argument’s premises are true. Strategies falling under each of these three categories are discussed in turn.
PURCHASING POWER PARITY WITH RANK TESTS FOR NONLINEAR COINTEGRATION IN AFRICAN COUNTRIES
Authors: Liu Yu‐shao , Su Chi‐wei
Published: March 2011

This study applies nonlinear cointegration to assess exchange rates with the corresponding relative prices and aggregate price levels for 20 African countries. We find that a nonparametric rank test has higher power than parametric testing procedures; a true data‐generating process of exchange rate is in fact a stationary nonlinear process. We examine the validity of purchasing power parity (PPP) from the nonparametric nonlinear point of view and provide robust evidence that clearly indicates PPP holds true for these countries. Hence, the long‐run African countries exchange rate adjustments are in equilibrium with the relevant fundamentals as suggested by the PPP hypothesis in a nonlinear way.
Equine periocular neoplasia: Current concepts in aetiopathogenesis and emerging treatment modalities
Authors: GIULIANO E. A.
Published: March 2011

Neoplastic adnexal disease represents one of the most frequently encountered and therapeutically challenging ophthalmic problems of horses. This paper reviews current concepts in equine periocular neoplasia. Specifically, a literature‐based review of the aetiopathogenesis of the most common tumours to affect the equine eyelid (squamous cell carcinoma, sarcoid, melanoma and lymphosarcoma) is provided. Current and emerging treatment modalities, including photodynamic therapy, are reviewed.
Neuro‐ophthalmology: A review
Authors: MAYHEW I. G. JOE
Published: March 2011

Evaluation of horses for eye problems and for suspected impairment of visual acuity often requires a thorough neuro‐ophthalmic examination to be conducted. Along with a full ophthalmic evaluation, the results of such an examination should indicate the likely site of any lesion(s) accounting for blindness, miosis, mydriasis, anisocoria, Horner's syndrome, strabismus, facial paralysis and facial spasm, nystagmus and other signs of vestibular disease, and cerebellar disorders, that may be present. Such a thorough examination with guidance for correct interpretation of findings is given here.
Hepatoprotective effects of geniposide in a rat model of nonalcoholic steatohepatitis
Authors: Ma Taotao , Huang Cheng , Zong Guojun , Zha Dajun , Meng Xiaoming , Li Jun , Tang Wenjian
Published: March 2011

Objectives

Nonalcoholic steatohepatitis (NASH), a metabolic disorder of the liver, may gradually evolve into fibrosis or cirrhosis. Recent studies have suggested that geniposide can effectively inhibit experimental liver fibrosis. Therefore, the aim of this study was to determine whether geniposide can influence the early phase of fibrogenesis in an animal model of NASH.

Methods

Male Sprague–Dawley rats were given a high fat diet alone or the same diet combined with geniposide at doses of 25, 50 or 100 mg/kg for six weeks. Ten rats received corresponding solvent as a normal control.

Key findings

Treatment with geniposide could improve liver histology through reducing the elevated liver index (liver weight/body weight), serum alanine aminotransferase and aspartate aminotransferase. Total cholesterol, triglycerides and free fatty acids in serum and liver decreased in geniposide-treated rats. Furthermore, geniposide increased serum insulin levels but reduced serum tumour necrosis factor-α level in high-fat diet rats. In addition, geniposide suppressed expression of CYP2E1 and increased peroxisome proliferator-activated receptor-α (PPARα) expression. These benefits may be associated with increased superoxide dismutase and decreased malondialdehyde in liver.

Conclusions

Geniposide exerts protective effects against hepatic steatosis in rats fed with a high fat diet; the underlying mechanism may be associated with its antioxidant actions or regulation of adipocytokine release and expression of PPARα.
Oxygen Isotope Variations at the Margin of a CAI Records Circulation Within the Solar Nebula
Authors: Simon Justin I. , Hutcheon Ian D. , Simon Steven B. , Matzel Jennifer E. P. , Ramon Erick C. , Weber Peter K. , Grossman Lawrence , DePaolo Donald J.
Published: March 2011

Isotope measurements within an inclusion in a meteorite reveal a record of processes in the early solar system.
Helix-Rod Host-Guest Complexes with Shuttling Rates Much Faster than Disassembly
Authors: Gan Quan , Ferrand Yann , Bao Chunyan , Kauffmann Brice , Grélard Axelle , Jiang Hua , Huc Ivan
Published: March 2011

A molecular helix wrapped around a rigid rod can unwind and move between binding sites.
Paleoindian Seafaring, Maritime Technologies, and Coastal Foraging on California’s Channel Islands
Authors: Erlandson Jon M. , Rick Torben C. , Braje Todd J. , Casperson Molly , Culleton Brendan , Fulfrost Brian , Garcia Tracy , Guthrie Daniel A. , Jew Nicholas , Kennett Douglas J. , Moss Madonna L. , Reeder Leslie , Skinner Craig , Watts Jack , Willis Lauren
Published: March 2011

Archaeological sites reveal a variety of tools used to hunt marine birds, mammals, and fish 12,000 years ago.
Toward Synthesis of Arbitrary Optical Waveforms
Authors: Yavuz Deniz D.
Published: March 2011

Light with different frequencies (colors) can be combined to synthesize optical waveforms such as square and sawtooth waves, as well as short pulses.
Gradient Scaling and Growth
Authors: Le Goff Loïc , Lecuit Thomas
Published: March 2011

Tissue growth is controlled by the temporal variation in signaling by a morphogen along its concentration gradient.
Molecular Motors, Beauty in Complexity
Authors: Spudich James A.
Published: March 2011

X-ray crystallography provides some surprising insights into the dynein class of molecular motors.
Scientists Fear WFIRST Will Be Trailing the Pack
Authors: Bhattacharjee Yudhijit
Published: March 2011

The 1990s were a decade of glory for U.S. astronomers, including the discovery of dark energy and planets outside the solar system. But the instrument that they say would keep them at the forefront may be too costly for the U.S. government to build.
Do Island Sites Suggest a Coastal Route to the Americas?
Authors: Balter Michael
Published: March 2011

On page 1181 of this week's issue of
Science
, archaeologists detail the remains of hunts carried out 12,000 years ago on Santa Rosa Island off the coast of California: thousands of bird, fish, and sea-mammal bones, as well as shells and stone points likely used in hunting.
Ten Years After Buddhas Destroyed, Afghans Work to Save Monastery
Authors: Lawler Andrew
Published: March 2011

The 10th anniversary of the Taliban's destruction of the world's two largest Buddha statues and next week's opening of the first exhibit on the finds at Mes Aynak, another Buddhist complex 200 kilometers to the south, are putting the spotlight on Afghanistan's beleaguered heritage.
A Startling Villain
Authors: Stone Richard
Published: March 2011

The surprising culprit disease sleuths uncovered when villagers in northeastern Bangladesh began dying 3 years ago sends a chilling warning to regions facing food shortages.
Heavy Metal Tolerance of Fe(III)-Reducing Microbial Communities in Contaminated Creek Bank Soils
Authors: Burkhardt Eva-Maria , Bischoff Sebastian , Akob Denise M. , Büchel Georg , Küsel Kirsten
Published: March 2011

Fe(III)-reducing soil enrichment cultures can tolerate 100 μM Cu and Cd, 150 μM Co, 600 μM Ni, and 2,500 μM Zn. Metal-tolerant cultures were dominated by
Geobacter
-related
Deltaproteobacteria
and Gram-positive
Firmicutes
spp.
(Clostridia
and
Sedimentibacter
). A Cd- and Cu-tolerant Fe(III)-reducing coculture of
Desulfosporosinus
and
Desulfitobacterium
indicated the importance of the
Firmicutes
for Fe(III) reduction in the presence of metals.
Real-Time Monitoring of Salmonella enterica in Free-Range Geese
Authors: Christensen L. S. , Josefsen M. H. , Pedersen K. , Christensen J. , Bonnichsen L. , Sørensen G. , Hoorfar J.
Published: March 2011

Free-range geese were sampled longitudinally and
Salmonella
isolates characterized to reveal highly diverging colonization dynamics. One flock was intermittently colonized with one strain of
Salmonella enterica
serovar Enteritidis from 2 weeks of age, while in another,
S. enterica
serovar Mbandaka appeared after 9 weeks, without dissemination but with multiple serovars appearing at later stages.
Quantitative Analysis of Histidine Decarboxylase Gene (hdcA) Transcription and Histamine Production by Streptococcus thermophilus PRI60 under Conditions Relevant to Cheese Making
Authors: Rossi Franca , Gardini Fausto , Rizzotti Lucia , La Gioia Federica , Tabanelli Giulia , Torriani Sandra
Published: March 2011

This study evaluated the influence of parameters relevant for cheese making on histamine formation by
Streptococcus thermophilus
. Strains possessing a histidine decarboxylase (
hdcA
) gene represented 6% of the dairy isolates screened. The most histaminogenic,
S. thermophilus
PRI60, exhibited in skim milk a high basal level of expression of
hdcA
, upregulation in the presence of free histidine and salt, and repression after thermization. HdcA activity persisted in cell extracts, indicating that histamine might accumulate after cell lysis in cheese.
Diverse Geno- and Phenotypes of Persistent Listeria monocytogenes Isolates from Fermented Meat Sausage Production Facilities in Portugal
Authors: Ferreira V. , Barbosa J. , Stasiewicz M. , Vongkamjan K. , Moreno Switt A. , Hogg T. , Gibbs P. , Teixeira P. , Wiedmann M.
Published: March 2011

The persistence of
Listeria monocytogenes
in food-associated environments represents a key factor in transmission of this pathogen. To identify persistent and transient strains associated with production of fermented meat sausages in northern Portugal, 1,723
L. monocytogenes
isolates from raw material and finished products from 11 processors were initially characterized by random amplification of polymorphic DNA (RAPD), PCR-based molecular serotyping, and epidemic clone characterization, as well as cadmium, arsenic, and tetracycline resistance typing. Pulsed-field gel electrophoresis (PFGE) typing of 240 representative isolates provided evidence for persistence of
L. monocytogenes
for periods of time ranging from 10 to 32 months for all seven processors for which isolates from different production dates were available. Among 50
L. monocytogenes
isolates that included one representative for each PFGE pattern obtained from a given sample, 12 isolates showed reduced invasion efficiency in Caco-2 cells, including 8 isolates with premature stop codons in
inlA
. Among 41 isolates representing sporadic and persistent PFGE types, 22 isolates represented lysogens. Neither strains with reduced invasion nor lysogens were overrepresented among persistent isolates. While the susceptibility of isolates to lysogenic phages also did not correlate with persistence, it appeared to be associated with molecular serotype. Our data show the following. (i) RAPD may not be suitable for analysis of large sets of
L. monocytogenes
isolates. (ii) While a large diversity of
L. monocytogenes
subtypes is found in Portuguese fermented meat sausages, persistence of
L. monocytogenes
in this food chain is common. (iii) Persistent
L. monocytogenes
strains are diverse and do not appear to be characterized by unique genetic or phenotypic characteristics.
The Swarming Motility of Pseudomonas aeruginosa Is Blocked by Cranberry Proanthocyanidins and Other Tannin-Containing Materials
Authors: O'May Che , Tufenkji Nathalie
Published: March 2011

Bacterial motility plays a key role in the colonization of surfaces by bacteria and the subsequent formation of resistant communities of bacteria called biofilms. Derivatives of cranberry fruit, predominantly condensed tannins called proanthocyanidins (PACs) have been reported to interfere with bacterial adhesion, but the effects of PACs and other tannins on bacterial motilities remain largely unknown. In this study, we investigated whether cranberry PAC (CPAC) and the hydrolyzable tannin in pomegranate (PG; punicalagin) affected the levels of motilities exhibited by the bacterium
Pseudomonas aeruginosa
. This bacterium utilizes flagellum-mediated swimming motility to approach a surface, attaches, and then further spreads via the surface-associated motilities designated swarming and twitching, mediated by multiple flagella and type IV pili, respectively. Under the conditions tested, both CPAC and PG completely blocked swarming motility but did not block swimming or twitching motilities. Other cranberry-containing materials and extracts of green tea (also rich in tannins) were also able to block or impair swarming motility. Moreover, swarming bacteria were repelled by filter paper discs impregnated with many tannin-containing materials. Growth experiments demonstrated that the majority of these compounds did not impair bacterial growth. When CPAC- or PG-containing medium was supplemented with surfactant (rhamnolipid), swarming motility was partially restored, suggesting that the effective tannins are in part acting by a rhamnolipid-related mechanism. Further support for this theory was provided by demonstrating that the agar surrounding tannin-induced nonswarming bacteria was considerably less hydrophilic than the agar area surrounding swarming bacteria. This is the first study to show that natural compounds containing tannins are able to block
P. aeruginosa
swarming motility and that swarming bacteria are repelled by such compounds.
Substructure within Salmonella enterica subsp. enterica Isolates from Australian Wildlife
Authors: Parsons Sandra K. , Bull C. Michael , Gordon David M.
Published: March 2011

Multilocus sequence typing of 56
Salmonella enterica
subsp.
enterica
strains isolated from Australian wildlife hosts was performed. The results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. Strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution.
Structure-Function Analysis of Dynein Light Chain 1 Identifies Viable Motility Mutants in Bloodstream-Form Trypanosoma brucei
Authors: Ralston Katherine S. , Kisalu Neville K. , Hill Kent L.
Published: March 2011

The flagellum of
Trypanosoma brucei
is an essential and multifunctional organelle that is receiving increasing attention as a potential drug target and as a system for studying flagellum biology. RNA interference (RNAi) knockdown is widely used to test the requirement for a protein in flagellar motility and has suggested that normal flagellar motility is essential for viability in bloodstream-form trypanosomes. However, RNAi knockdown alone provides limited functional information because the consequence is often loss of a multiprotein complex. We therefore developed an inducible system that allows functional analysis of point mutations in flagellar proteins in
T. brucei
. Using this system, we identified point mutations in the outer dynein light chain 1 (LC1) that allow stable assembly of outer dynein motors but do not support propulsive motility. In procyclic-form trypanosomes, the phenotype of LC1 mutants with point mutations differs from the motility and structural defects of LC1 knockdowns, which lack the outer-arm dynein motor. Thus, our results distinguish LC1-specific functions from broader functions of outer-arm dynein. In bloodstream-form trypanosomes, LC1 knockdown blocks cell division and is lethal. In contrast, LC1 point mutations cause severe motility defects without affecting viability, indicating that the lethal phenotype of LC1 RNAi knockdown is not due to defective motility. Our results demonstrate for the first time that normal motility is not essential in bloodstream-form
T. brucei
and that the presumed connection between motility and viability is more complex than might be interpreted from knockdown studies alone. These findings open new avenues for dissecting mechanisms of flagellar protein function and provide an important step in efforts to exploit the potential of the flagellum as a therapeutic target in African sleeping sickness.
Identification of Streptococcus pneumoniae Cps2C Residues That Affect Capsular Polysaccharide Polymerization, Cell Wall Ligation, and Cps2D Phosphorylation
Authors: Byrne James P. , Morona Judy K. , Paton James C. , Morona Renato
Published: March 2011

A number of single amino acid substitutions throughout
Streptococcus pneumoniae
Cps2C were found to affect its function and confer either a mucoid or a small colony phenotype. These mutants exhibit significant changes in capsular polysaccharide (CPS) profile relative to that of wild-type pneumococci. The introduced mutations affect either polymerization or ligation of CPS to the cell wall and/or Cps2D phosphorylation.
Partial Functional Replacement of CymA by SirCD in Shewanella oneidensis MR-1
Authors: Cordova Carmen D. , Schicklberger Marcus F. R. , Yu Yang , Spormann Alfred M.
Published: March 2011

The gammaproteobacterium
Shewanella oneidensis
MR-1 utilizes a complex electron transfer network composed primarily of
c
-type cytochromes to respire under anoxic conditions a variety of compounds, including fumarate, nitrate, and dimethyl sulfoxide (DMSO), in addition to the minerals Fe(III) and Mn(IV). Central to several respiratory pathways is CymA, a cytoplasmic membrane-bound tetraheme
c
-type cytochrome that functions as the major hydroquinone dehydrogenase. To investigate functional redundancy and plasticity in
S. oneidensis
MR-1 electron transport, we isolated Δ
cymA
suppressor mutants and characterized one biochemically and genetically. Interestingly, in the characterized Δ
cymA
suppressor mutant, respiration of fumarate, ferric citrate, and DMSO was restored but that of nitrate was not. The suppression was found to be due to transcriptional activation of
sirC
and
sirD
, encoding a periplasmic iron sulfur protein and an integral membrane hydroquinone dehydrogenase, respectively. Biochemical
in vitro
reconstitution experiments confirmed electron transport between formate and fumarate via fumarate reductase by suppressor membrane fractions. The suppression was found to be caused by insertion of an ISSod1 element upstream of the
sirCD
transcriptional start site, generating a novel, constitutively active hybrid promoter. This work revealed that adaptation of an alternative electron transfer pathway from quinol to terminal oxidoreductases independent of CymA occurs rapidly in
S. oneidensis
MR-1.
Amino Acid Residues in the GerAB Protein Important in the Function and Assembly of the Alanine Spore Germination Receptor of Bacillus subtilis 168
Authors: Cooper Gareth R. , Moir Anne
Published: March 2011

The paradigm
gerA
operon is required for endospore germination in response to
l
-alanine as the sole germinant, and the three protein products, GerAA, GerAB, and GerAC are predicted to form a receptor complex in the spore inner membrane. GerAB shows homology to the amino acid-polyamine-organocation (APC) family of single-component transporters and is predicted to be an integral membrane protein with 10 membrane-spanning helices. Site-directed mutations were introduced into the
gerAB
gene at its natural location on the chromosome. Alterations to some charged or potential helix-breaking residues within membrane spans affected receptor function dramatically. In some cases, this is likely to reflect the complete loss of the GerA receptor complex, as judged by the absence of the germinant receptor protein GerAC, which suggests that the altered GerAB protein itself may be unstable or that the altered structure destabilizes the complex. Mutants that have a null phenotype for
l
-alanine germination but retain GerAC protein at near-normal levels are more likely to define amino acid residues of functional, rather than structural, importance. Single-amino-acid substitutions in each of the GerAB and GerAA proteins can prevent incorporation of GerAC protein into the spore; this provides strong evidence that the proteins within a specific receptor interact and that these interactions are required for receptor assembly. The lipoprotein nature of the GerAC receptor subunit is also important; an amino acid change in the prelipoprotein signal sequence in the
gerAC1
mutant results in the absence of GerAC protein from the spore.