bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric Oxide Measured by a Porphyrinic Micro Sensor in Rat Brain after Transient Middle Cerebral Artery Occlusion
Authors: Malinski T. , Bailey F. , Zhang Z. G. , Chopp M.
Published: May 2011

We measured, in vivo, the local concentration of nitric oxide (NO) in cerebral tissue, during and after transient middle cerebral artery occlusion in the rat (n = 8). Baseline concentration of NO was <10−8 M; upon initiation of ischemia, NO concentration increased to ∼10−6 M and then declined. Reperfusion likewise stimulated an increase in NO concentration to above baseline level. Administration of N-nitro-l-arginine methyl ester (n = 4), an inhibitor of nitric oxide synthase, before onset of ischemia, maintained NO at basal levels. Our data indicate that large increases in NO occur at onset of ischemia, which may affect tissue response to an ischemic insult.
Thermal Sensitivity of Hypoxic Responses in Neocortical Brain Slices
Authors: Hiramatsu Ken-Ichiro , Kassell Neal F. , Lee Kevin S.
Published: May 2011

Electrophysiological responses to transient hypoxia were studied in neocortical brain slices from adult gerbils. Evoked responses and direct current (DC) potentials were recorded in layer III of the parietal cortex under normoxic and hypoxic conditions. The excitatory synaptic component of the evoked waveform was identified by its sensitivity to calcium and 6,7-dinitroquinoxaline-2,3-dione (DNQX). Under normoxic conditions, hypothermia reduced excitatory synaptic responses in a temperature-dependent manner. Under hypoxic conditions, hypothermia prolonged the delays to synaptic loss and hypoxic depolarization in a temperature-dependent manner. Synaptic recovery following a fixed period under hypoxic depolarization was greatly enhanced when hypoxia was administered at reduced temperature. The findings demonstrate that evoked responses are reduced under hypothermic conditions, but that these responses are sustained for a longer period of time during hypoxia. The data suggest that hypothermia protects against hypoxic damage to excitatory synaptic mechanisms in the neocortex both by prolonging the delay to hypoxic depolarization, and by extending the period of hypoxic depolarization that can be tolerated.
Early Detection of Alzheimer's Disease: A Statistical Approach Using Positron Emission Tomographic Data
Authors: Azari N. P. , Pettigrew K. D. , Schapiro M. B. , Haxby J. V. , Grady C. L. , Pietrini P. , Salerno J. A. , Heston L. L. , Rapoport S. I. , Horwitz B.
Published: May 2011

Correlational analysis of regional cerebral glucose metabolism (rCMRglc) obtained by high-resolution positron emission tomography (PET) has demonstrated reduced neocortical rCMRglc interactions in mildly/moderately demented patients with probable Alzheimer's disease (AD). Thus, identification of individual differences in patterns of rCMRglc interactions may be important for the early detection of AD, particularly among individuals at greater risk for developing AD (e.g., those with a family history of AD). Recently, a statistical procedure, using multiple regression and discriminant analysis, was developed to assess individual differences in patterns of rCMRglc interdependencies. We applied this new statistical procedure to resting rCMRglc PET data from mildly/moderately demented patients with probable AD and age/sex-matched controls. The aims of the study were to identify a discriminant function that would (a) distinguish patients from controls and (b) identify an AD pattern in an individual at risk for AD with isolated memory impairment whose initial PET scan showed minor abnormalities, but whose second scan showed parietal hypometabolism, coincident with further cognitive decline. Two discriminant functions, reflecting interactions involving regions most involved in reduced correlations in probable AD, correctly classified 87% of the patients and controls, and successfully identified the first scan of the at-risk individual as AD (probability >0.70). The results suggest that this statistical approach may be useful for the early detection of AD.
Reliability of Regional Cerebral Blood Flow Activation to Cognitive Tasks in Elderly Normal Subjects
Authors: Skolnick Brett E. , Gur Ruben C. , Stern Matthew B. , Hurtig Howard I.
Published: May 2011

The assessment of cerebral blood flow (CBF) using noninvasive 133Xe techniques provides an indirect measurement of cortical metabolic activity. The utility of this method in longitudinal clinical studies depends on the stability and reproducibility of resting and activated flow measures. We evaluated CBF in a sample of 16 elderly normal subjects (aged 54–73 years) at rest and during task performance in two sessions separated by an average of 9 weeks. Resting global CBF was lower in the second session, a finding consistent with the known effects of habituation previously reported. Regionally specific activated CBF did not change with repeated measurements. The results provide evidence that the 133Xe technique is reliable and of potential utility in evaluating the effect of the natural course of brain disease, as well as the effects of therapeutic interventions on brain activity.
Electrical and Mechanical Changes during Anoxic Contractions of the Isolated Canine Basilar Artery
Authors: Nagao Tetsuhiko , Vanhoutte Paul M.
Published: May 2011

Isometric tension and membrane potential were measured to determine the electrophysiological events occurring during anoxia in the isolated canine basilar artery. Anoxia induced transient contractions which were inhibited by the Ca2+-channel inhibitor, diltiazem, and were abolished in Ca2+-free solution. Anoxic contractions were accompanied by membrane depolarizations, which were resistant to diltiazem. When matched contractions were obtained with anoxia and high K+, the level of membrane depolarization was smaller during anoxic contractions. These results support the importance of voltage-dependent Ca2 + influx in the generation of anoxic contractions in the canine basilar artery. However, membrane depolarization does not fully account for these anoxic contractions.
Human Visual Cortical Function during Photic Stimulation Monitoring by Means of near-Infrared Spectroscopy
Authors: Kato Toshinori , Kamei Atsushi , Takashima Sachio , Ozaki Takeo
Published: May 2011

Near-infrared spectroscopy (NIRS) was used to monitor human visual cortical function during and after photic stimulation (PS) in five adult volunteers. Cerebral blood volume (CBV) increased on the occipital surface during PS, but NIRS parameters did not change on the frontal surface. The increase in CBV was caused by a rapid increase in oxyhemoglobin with but a small increase in deoxyhemoglobin, suggesting cerebral vascular dilatation with decreased oxygen consumption. After PS stopped, CBV promptly decreased and then slightly increased again. Cytochrome aa3 did not show any change during and after PS. These phenomena reappeared following repeated PS in all five subjects. These results may represent the first step in the development of NIRS imaging.
Local Cerebral Blood Flow in Rats with Congenital Hydrocephalus
Authors: Jones H. C. , Richards H. K. , Bucknall R. M. , Pickard J. D.
Published: May 2011

Local cerebral blood flow (LCBF) has been measured by [14C]iodoantipyrine quantitative autoradiography in H-Tx rats with inherited congenital hydrocephalus at 10, 21, and 30 days after birth. LCBF at 10 days was uniformly low in all ten brain regions studied and not significantly different between hydrocephalic and age-matched control rats. By 21 days LCBF had increased significantly in control rats. LCBF was significantly lower (<69%) in the hydrocephalics in all cortical regions and in the inferior colliculus LCBF at both 21 and 30 days. The cerebellar cortex, pons, and caudate were not significantly affected. At 30 days LCBF ranged from 55 to 115 ml 100 g−1 min−1 for hydrocephalics and from 100 to 183 ml 100 g−1 min−1 for controls.
Blockade of Nitric Oxide Synthesis in Rats Strongly Attenuates the CBF Response to Extracellular Acidosis
Authors: Niwa Kiyoshi , Lindauer Ute , Villringer Arno , Dirnagl Ulrich
Published: May 2011

We tested the hypothesis that the CBF response to extracellular acidosis is mediated by nitric oxide (NO). A closed cranial window, superfused with artificial CSF (aCSF), was implanted over the parietal cortex in anesthetized and ventilated Wistar rats. Regional cerebral blood flow (rCBF) was measured continuously with laser-Doppler flowmetry (LDF). The reaction of rCBF to hypercapnia (Paco2 from 30.5 ± 1.8 to 61.3 ± 5.8 mm Hg by adding CO2 to the inspiratory gas) was 2.9 ± 1.4%/mm Hg, and the reaction of rCBF to H+ (superfusion of acidic aCSF, pH 7.07 ± 0.05) was 101.7 ± 24.7%/pH unit. The regional NO synthase (NOS) activity was blocked by superfusing aCSF containing 10−3 M Nω-nitro-L-arginine (L-NA, n = 10). After 30 min of L-NA superfusion, rCBF was reduced to 80.1 ± 6.5% of baseline, and the rCBF responses to hypercapnia (Paco2 from 30.9 ± 2.9 to 58.8 ± 7.7 mm Hg) and extracellular acidosis (aCSF pH 7.08 ± 0.06) were reduced to 0.8 ± 1.1%/ mm Hg and 10.1 ± 23.0%/pH unit, respectively (both p < 0.001). This effect was stereospecific since aCSF containing 10−3 M Nω-nitro-D-arginine affected neither baseline rCBF nor the response to H+ ( n = 5). The NOS blockade did not affect the vasodilatation by the NO donor sodium nitroprusside ( n = 5, 114.3 ± 25.1% before vs. 130.2 ± 24.7% after NOS blockade). The results confirm the involvement of NO in the CBF reaction to hypercapnia and demonstrate for the first time that NOS blockade also strongly attenuates the H+ response of the cerebral vasculature. We speculate that extracellular acidification triggers the production of NO.
Increased Adipose Protein Carbonylation in Human Obesity
Authors: Frohnert Brigitte I. , Sinaiko Alan R. , Serrot Federico J. , Foncea Rocio E. , Moran Antoinette , Ikramuddin Sayeed , Choudry Umar , Bernlohr David A.
Published: May 2011

Insulin resistance is associated with obesity but mechanisms controlling this relationship in humans are not fully understood. Studies in animal models suggest a linkage between adipose reactive oxygen species (ROS) and insulin resistance. ROS oxidize cellular lipids to produce a variety of lipid hydroperoxides that in turn generate reactive lipid aldehydes that covalently modify cellular proteins in a process termed carbonylation. Mammalian cells defend against reactive lipid aldehydes and protein carbonylation by glutathionylation using glutathione‐S‐transferase A4 (GSTA4) or carbonyl reduction/oxidation via reductases and/or dehydrogenases. Insulin resistance in mice is linked to ROS production and increased level of protein carbonylation, mitochondrial dysfunction, decreased insulin‐stimulated glucose transport, and altered adipokine secretion. To assess protein carbonylation and insulin resistance in humans, eight healthy participants underwent subcutaneous fat biopsy from the periumbilical region for protein analysis and frequently sampled intravenous glucose tolerance testing to measure insulin sensitivity. Soluble proteins from adipose tissue were analyzed using two‐dimensional gel electrophoresis and the major carbonylated proteins identified as the adipocyte and epithelial fatty acid‐binding proteins. The level of protein carbonylation was directly correlated with adiposity and serum free fatty acids (FFAs). These results suggest that in human obesity oxidative stress is linked to protein carbonylation and such events may contribute to the development of insulin resistance.
Downregulation of Hepatic Glucose‐6‐Phosphatase‐α in Patients With Hepatic Steatosis
Authors: Konopelska Sarah , Kienitz Tina , Quinkler Marcus
Published: May 2011

Glucose‐6‐phosphate transporter (G6PT) and microsomal glucose‐6‐phosphatase‐α (G6Pase‐α) perform the terminal step in glycogenolysis and gluconeogenesis. Deficiency of these proteins leads to glycogen storage diseases. Partial inhibition of G6Pase in rats results in increased hepatic triglyceride content and de novo lipogenesis leading to hepatic steatosis. Hepatic steatosis represents hepatic manifestation of the metabolic syndrome. We investigated molecular mechanisms that may explain the relationship between fatty liver and G6Pase‐α in humans in detail. A total of 27 patients (11 men, 16 women) underwent liver biopsy. Histological diagnosis identified nonfatty liver in seven patients and nonalcoholic fatty liver in 20 patients. We quantified G6Pase‐α and G6PT mRNA expression by real‐time PCR. Anthropometric measurements and analysis of plasma lipids and liver enzymes were performed. Patients with fatty liver showed no significant differences in age, HOMAIR (homeostasis model assessment of insulin resistance), BMI, liver enzymes or waist‐to‐hip ratio compared to those with nonfatty liver, but total plasma cholesterol levels and liver fat content were higher in patients with fatty liver (P < 0.05). G6Pase‐α and G6PT mRNA expressions were significantly downregulated in fatty compared to histologically normal liver (P < 0.05). G6Pase‐α and G6PT mRNA expressions correlated positively (R2 = 0.406 P < 0.05). Both expressions did not correlate with age, BMI, aspartate transaminase, alanine transaminase, alkaline phosphatase, γ‐glutamyl transferase, triglycerides or glucose levels. Our data suggest that expression of hepatic G6Pase‐α and G6PT are closely interlinked. Downregulation of G6Pase‐α in fatty liver might be associated with hepatic fat accumulation and pathogenesis of hepatic steatosis.
Amelioration of Lipid Abnormalities by α‐Lipoic acid Through Antioxidative and Anti‐Inflammatory Effects
Authors: Zhang Yongyan , Han Ping , Wu Na , He Bing , Lu Yan , Li Shuwen , Liu Yang , Zhao Sheng , Liu Letong , Li Yan
Published: May 2011

Recent data have revealed that oxidative products and inflammatory mediators are increased in the insulin‐resistant states of obesity and type 2 diabetes mellitus (T2DM). Obese patients with impaired glucose tolerance (IGT) are at high risk for developing T2DM and have high incidence of dyslipidemia. α‐Lipoic acid (ALA) is a potent antioxidant with insulin sensitizing activity. However, it is not clear whether ALA is effective on lipid parameters in humans. This study has investigated 22 obese subjects with IGT (obese‐IGT), 13 of whom underwent 2‐week ALA treatment, 600 mg intravenously once daily. Before and after the treatment, euglycemic‐hyperinsulinemic clamps were used to measure insulin sensitivity. Meanwhile, plasma lipids, oxidative products, and chronic inflammatory markers were measured. After treatment of ALA in obese‐IGT patients, insulin sensitivity was improved, insulin sensitivity index (ISI) impressively enhanced by 41%. Plasma levels of free fatty acids (FFAs), triglyceride (TG), total cholesterol (T‐Chol), low density lipoprotein‐cholesterol (LDL‐Chol), small dense LDL‐Chol (sd‐LDL), oxidized LDL‐Chol (ox‐LDL‐Chol), very low density lipoprotein‐cholesterol (VLDL‐Chol) were all significantly decreased (P < 0.01). At the same time, both plasma oxidative products (malondialdehyde (MDA), 8‐iso‐prostaglandin) and inflammatory markers (tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6)) were remarkably decreased (P < 0.01), while adiponectin was increased (P < 0.01). There are significant negative correlations between ISI and plasma FFAs, sd‐LDL‐Chol, ox‐LDL‐Chol, MDA, 8‐iso‐prostaglandin, TNF‐α, and IL‐6, and positive correlations with HDL‐Chol and adiponectin in obese‐IGT patients. The results indicate that short‐term treatment with ALA can improve insulin sensitivity and plasma lipid profile possibly through amelioration of oxidative stress and chronic inflammatory reaction in obese patients with IGT.
Clinical Correlates of the Weight Bias Internalization Scale in a Sample of Obese Adolescents Seeking Bariatric Surgery
Authors: Roberto Christina A. , Sysko Robyn , Bush Jennifer , Pearl Rebecca , Puhl Rebecca M. , Schvey Natasha A. , Dovidio John F.
Published: May 2011

The aim of this study was to evaluate psychometric properties and clinical correlates of the Weight Bias Internalization Scale (WBIS) in a sample of obese adolescents seeking bariatric surgery. Sixty five adolescents enrolled in a bariatric surgery program at a large, urban medical center completed psychiatric evaluations, self‐report questionnaires including the WBIS and other measures of psychopathology and physical assessments. The WBIS had high internal consistency (Cronbach's α = 0.92). As in previous research with adults, the one underlying factor structure was replicated and 10 of the original 11 items were retained. The scale had significant partial correlations with depression (r = 0.19), anxiety (r = 0.465), social, and behavioral problems (r = 0.364), quality of life (r = −0.480), and eating (r = 0.579), shape (r = 0.815), and weight concerns (r = 0.545), controlling for BMI. However, WBIS scores did not predict current or past psychiatric diagnosis or treatment or past suicidal ideation. Overall, the WBIS had excellent psychometric properties in a sample of obese treatment‐seeking adolescents and correlated significantly with levels of psychopathology. These findings suggest that the WBIS could be a useful tool for healthcare providers to assess internalized weight bias among treatment‐seeking obese youth. Assessment of internalized weight bias among this clinical population has the potential to identify adolescents who might benefit from information on coping with weight stigma, which in turn may augment weight loss efforts.
Race, Childhood Insulin, Childhood Caloric Intake, and Class 3 Obesity at Age 24: 14‐Year Prospective Study of Schoolgirls
Authors: Morrison John A. , Glueck Charles J. , Daniels Stephen R. , Wang Ping
Published: May 2011

The prevalence of Class 3 obesity (BMI ≥40 kg/m2) has more than doubled in the past 25 years. In a 14‐year prospective study from age 10 to 24 of a biracial schoolgirl cohort (293 black, 256 white), we assessed childhood correlates of Class 3 BMI at age 24. Of 42 girls with Class 3 BMI at age 24, 36 (86%) were black. By logistic regression, significant explanatory variables of Class 3 BMI at age 24 included top decile waist circumference at age 11 (odds ratio (OR) 5.7, 95% confidence interval (CI) 2.3–13.9, P = 0.0002), age 10 BMI ≥ the Center for Disease Control (CDC) 2000 top 15% (OR 7.0, 95% CI 2.5–19.3, P = 0.0002), and a three‐way interaction between race, childhood insulin, and average caloric intake from age 10 to age 19 (for each unit increase, OR 1.7 95% CI 1.3–2.2, P = 0.0003). Age 10 BMI, age 11 waist circumference, and interaction of race, childhood insulin, and childhood caloric intake predict Class 3 obesity in young adulthood, facilitating childhood identification of girls at high risk for developing Class 3 obesity.
Selenium Supplementation and Exercise: Effect on Oxidant Stress in Overweight Adults
Authors: Savory Louise A. , Kerr Catherine J. , Whiting Paul , Finer Nicholas , McEneny Jane , Ashton Tony
Published: May 2011

Both obesity and acute high‐intensity exercise increase oxidant stress levels. This study investigates whether selenium (Se) supplementation could be a potential effective therapy to reduce obesity‐associated oxidant stress and exercise‐induced oxidant stress. Ten normal‐weight (NW) (22.80 ± 0.41 kg/m2) and ten overweight (OW) healthy subjects (28.00 ± 0.81 kg/m2) were assessed during a randomized double‐blind Se supplementation study (200 µg sodium selenite/day for 3 weeks) with a 3‐week placebo control and inversion of treatment periods. Blood levels of lipid hydroperoxide (LH), superoxide dismutase (SOD), erythrocyte glutathione (GSH), and total antioxidant status (TAS), were measured at rest, pre‐, and postexercise (30 min 70% VO2 max before and after treatment (pretreatment (week 0 and 12) and post‐treatment (week 3 or 15)). At rest, compared to placebo, Se supplementation had no significant effect on LH, SOD, GSH, and TAS levels. However, Se supplementation decreased LH levels in the OW group, immediately postexercise (−0.25 ± 0.12 µmol/l, P = 0.05) compared to placebo treatment. Postexercise, with or without Se supplementation, no changes in TAS, SOD, and GSH levels were observed in both the NW and OW group. This study has highlighted a potential benefit of Se in reducing LH levels postexercise in OW individuals. Given that oxidant stress is a predictor of coronary events, it is imperative to better understand oxidant stress‐related responses to lifestyle factors (in particular “high‐risk” population groups) and potential antioxidant therapy.
Work Stress, Obesity and the Risk of Type 2 Diabetes: Gender‐Specific Bidirectional Effect in the Whitehall II Study
Authors: Heraclides Alexandros M. , Chandola Tarani , Witte Daniel R. , Brunner Eric J.
Published: May 2011

Psychosocial work stress has been linked to higher risk of type 2 diabetes (T2DM), with the effect being consistently higher among women than men. Also, work stress has been linked to prospective weight gain among obese men but weight loss among lean men. Here, we aimed to examine the interaction between work stress and obesity in relation to T2DM risk in a gender‐specific manner. We studied 5,568 white middle‐aged men and women in the Whitehall II study, who were free from diabetes at analysis baseline (1993). After 1993, diabetes was ascertained at six consecutive phases by an oral glucose tolerance test supplemented by self‐reports. Cox regression analysis was used to assess the association between job strain (high job demands/low job control) and 18‐year incident T2DM stratifying by BMI (BMI <30 kg/m2 vs. BMI ≥30 kg/m2). Overall, work stress was associated with incident T2DM among women (hazard ratio (HR) 1.41: 95% confidence intervals: 1.02; 1.95) but not among men (HR 0.87: 95% confidence interval 0.69; 1.11) (PINTERACTION = 0.017). Among men, work stress was associated with a lower risk of T2DM in nonobese (HR 0.70: 0.53; 0.93) but not in obese individuals (PINTERACTION = 0.17). Among women, work stress was associated with higher risk of T2DM in the obese (HR 2.01: 1.06; 3.92) but not in the nonobese (PINTERACTION = 0.005). Gender and body weight status play a critical role in determining the direction of the association between psychosocial stress and T2DM. The potential effect‐modifying role of gender and obesity should not be ignored by future studies looking at stress‐disease associations.
Cortical Auditory Evoked Potentials in Auditory Neuropathy Spectrum Disorder: Clinical Implications
Authors: Cardon Garrett , Sharma Anu
Published: May 2011

Standard clinical audiologic assessments have proven useful in the detection and diagnosis of auditory neuropathy spectrum disorder (ANSD). However, beyond initial diagnosis, clinicians have fewer tools to appropriately manage infants and young children with ANSD. While cortical auditory evoked potentials (CAEP) are not currently used routinely in the management of children with ANSD, mounting evidence suggests that they are not only recordable in this population, but that they may provide useful information regarding treatment and behavioral outcomes in children with ANSD. The report discusses the potential clinical utility of CAEPs in children with ANSD, using a case illustration.
Spoken Language Assessment Considerations for Children With Hearing Impairment When the Home Language Is Not English
Authors: Douglas Michael
Published: May 2011

Although the most prominent language in the United States is English, the U.S. is not a monolingual country. According to the U.S. Census in 2000, there were over 40 languages other than English spoken by 55 million people, with 34 million speaking Spanish or Spanish Creole. Given projections based on population studies and the prevalence of hearing loss in the Hispanic-American population, the number of persons who speak English as a second language will grow substantially over the next several decades. Hence, hearing health care professionals must be equipped to provide services for children who have hearing loss and speak English as a second language. The following article describes special considerations speech-language pathologists, audiologists, and educators should take into account when providing intervention designed to develop spoken language for children who have hearing loss and for whom the home language is not English.
A weighted coefficient model for estimation of Australian daily soil temperature at depths of 5cm to 100cm based on air temperature and rainfall
Authors: Horton Brian , Corkrey Ross
Published: May 2011

Soil temperatures are related to air temperature and rainfall on the current day and preceding days, and this can be expressed in a non-linear relationship to provide a weighted value for the effect of air temperature or rainfall based on days lag and soil depth. The weighted minimum and maximum air temperatures and weighted rainfall can then be combined with latitude and a seasonal function to estimate soil temperature at any depth in the range 5–100 cm. The model had a root mean square deviation of 1.21–1.85°C for minimum, average, and maximum soil temperature for all weather stations in Australia (mainland and Tasmania), except for maximum soil temperature at 5 and 10 cm, where the model was less precise (3.39° and 2.52°, respectively). Data for this analysis were obtained from 32–40 Bureau of Meteorology weather stations throughout Australia and the proposed model was validated using 5-fold cross-validation.
Soil carbon dynamics under different cropping and pasture management in temperate Australia: Results of three long-term experiments
Authors: Chan K. Y. , Conyers M. K. , Li G. D. , Helyar K. R. , Poile G. , Oates A. , Barchia I. M.
Published: May 2011

In addition to its important influence on soil quality and therefore crop productivity, soil organic carbon (SOC) has also been identified as a possible C sink for sequestering atmospheric carbon dioxide. Limited data are available on the impact of management practices on the rate of SOC change in agricultural soils in Australia. In this paper, results of three long-term trials (13–25 years) located near Wagga Wagga in temperate Australia were used to assess C dynamics under different tillage and stubble management practices, and under cropping intensities in pasture/crop rotations.
Experimental results confirm the importance of management practices and pasture in determining first the steady-state SOC concentrations that are characteristic of given rotations and crop management systems, and second the rates of change of SOC concentrations as they approach steady-state concentrations in agricultural soils of this agro-ecological zone. A long-term crop/pasture experiment at a site with initial high SOC showed that the rate of SOC change in different treatments ranged from –278 to +257 kg C/ha.year over 0–0.3 m soil depth. Under continuous cropping, even under conservation agriculture practices of no-tillage, stubble retention, and crop rotation, the high initial SOC stock (0–0.3 m) present after a long-term pasture phase was, at best, maintained but tended to decrease with increased tillage or stubble burning practices. The effect of tillage was greater than that of stubble management. Increases in SOC were observed only in rotations incorporating a pasture phase.
Our results suggest that improved soil nutrient and grazing management of permanent pasture can lead to an increase of 500–700 kg C/ha.year where the initial SOC concentrations are well below steady-state concentrations that could be expected after long periods of improved management. No difference was found between perennial pasture and annual pasture to the depth measured (0–0.3 m). Our results suggest that pasture holds the key to maintaining, and even increasing, SOC under crop/pasture in this environment.
Effects of irrigation frequency on ryegrass and white clover growth. 1. Experimental results
Authors: Sumanasena H. A. , Horne D. J. , Kemp P. D. , Scotter D. R.
Published: May 2011

The rising demand for the finite amount of water available for pasture irrigation in New Zealand means increasing interest in irrigation efficiency. The effects of frequency of sprinkler irrigation of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) were investigated near Palmerston North on Manawatu fine sandy loam (Dystric Fluventric Eutrochrept), using replicated plots of 1.5 m2. As values range from 12 to 90 mm for the reported soil water deficit at which stress first reduces pasture growth, with the most common values between 20 and 60 mm, deficits of 20 mm (involving irrigation about every 5 days if no rain fell), 40 mm, and 60 mm were chosen to trigger irrigation. There were replicated plots with and without superphosphate treatments for each irrigation and species treatment, as an interaction between fertility and the optimal trigger deficit was considered possible, and such interactions have rarely been investigated. There were also four non-irrigated plots. Yield was measured and soil water content monitored. Irrigating at a soil water deficit of 20 mm (meaning readily available water was always present in the top 150 mm of soil) rather than 60 mm resulted in significantly more ryegrass and white clover production over the irrigation season. This was particularly so when superphosphate was applied to the ryegrass.
Effects of irrigation frequency on ryegrass and white clover growth. 2. Improving irrigation efficiency
Authors: Horne D. J. , Sumanasena H. A. , Scotter D. R.
Published: May 2011

Growing concerns about limited water inputs for, and deleterious environmental outputs from, irrigation of pasture make the identification of more efficient scheduling strategies imperative. A climate-driven pasture production model is used to simulate the daily soil water deficit in the topsoil and subsoil, and so pasture production under a range of irrigation strategies. Soil water content and pasture production data from a companion paper, describing a Manawatu experiment where irrigation was applied to plots at trigger deficits of 20, 40, and 60 mm, were used to evaluate model parameters. The model was then used with 30 years of meteorological data to simulate a range of irrigation strategies at Palmerston North and Winchmore. Applying 20 mm of irrigation when a 20-mm trigger deficit is reached as opposed to 60 mm of irrigation at a 60-mm deficit increased the simulated average annual pasture response to irrigation by ~80%, but this increase was at the cost of ~40% more irrigation water. A suggested alternative strategy is to apply 20 mm of irrigation whenever a 60-mm trigger deficit is reached, which in summer will be about every 5 days if no rain falls. Keeping the topsoil moist most of the time, while leaving room for rainfall in the subsoil, will increase water use efficiency (the production response per mm of irrigation) by substantially reducing the irrigation requirement and drainage excess, even though it does not maximise production.
Influence of temperature and soil type on inhibition of urea hydrolysis by N-(n-butyl) thiophosphoric triamide in wheat and pasture soils in south-eastern Australia
Authors: Suter H. C. , Pengthamkeerati P. , Walker C , Chen D.
Published: May 2011

Incubation experiments were conducted to assess the effectiveness of N-(n-butyl) thiophosphoric triamide (NBPT) for inhibiting hydrolysis of urea in three wheat-growing soils and one pasture soil in south-eastern Australia, under a range of temperatures (5, 15, 25°C). The effectiveness of NBPT decreased with increasing temperature and with increasing urease activity. In the acidic pasture soil with high urease activity (186 μg N/g soil.h) and high organic carbon content (11%), NBPT (0.1% w/w urea) had little impact on urea hydrolysis rates over all temperatures, with <1% urea remaining at Day 14. In the alkaline, wheat-cropping soils with lower urease activity (54–90 μg N/g soil.h) and lower organic carbon content (<1.5%), NBPT was able to effectively reduce urea hydrolysis over 14–15 days at 5°C and 15°C (>55% urea remaining). At 25°C in the wheat soils, NBPT slowed the rate of urea hydrolysis, but by Days 14 and 15, <2% of the urea remained. NBPT applied at a rate of 0.1% urea would be an effective tool for slowing urea hydrolysis in the wheat-cropping soils under cool-climate conditions. The delay in urea hydrolysis in the pasture soil still provides the opportunity for increased flexibility in farm management, such as irrigation scheduling.
Spontaneous and aging-dependent development of arthritis in NADPH oxidase 2 deficiency through altered differentiation of CD11b+ and Th/Treg cells
Authors: Lee Kihyun , Won Hee Yeon , Bae Myung Ae , Hong Jeong-Ho , Hwang Eun Sook
Published: May 2011

Emerging evidence indicates that NADPH oxidase (NOX) and its reactive oxygen species (ROS) products modulate a variety of cellular events, including proliferation, differentiation, and apoptosis. In this study, we investigated the functions of NOX2 and ROS in immune modulation using NOX2 knockout (KO) mice. Interestingly, NOX2 KO mice spontaneously developed arthritis with onset at 6–7 wk of age and high incidence (60%) at 15–18 wk of age. Arthritis severity in NOX2 KO mice was proportionally increased with age and higher in females than in males. Bone destruction was confirmed by microcomputed tomography scanning and histological analyses of joints. Inflammatory factors, including TNF-α, IL-1β, and RANKL, and serum level of anti–type II collagen IgG were significantly increased in NOX2 KO mice. In addition, NOX2 deficiency perturbed the immune system upon aging. NOX2 KO mice demonstrated preferred development of CD11b+Gr-1+ myeloid cells with profound production of proinflammatory cytokines and augmented expression of IL-17 through the activation of STAT3 and RORγt in vivo. NOX2 deficiency increased differentiation of effector Th cells in vitro and decreased CD25+FoxP3+ Treg cells both in vitro and in vivo. Furthermore, adoptive transfer of NOX2-deficient CD4
+
T cells into RAG KO mice increased arthritic inflammation compared with WT cells. These results demonstrated that NOX2 deficiency affected the development of CD11b+ myeloid cells and Th17/Treg cells, and thus promoted inflammatory cytokine production and inflammatory arthritis development, strongly supporting a crucial role for ROS generation in the modulation of Th17/Treg cell development and its related inflammatory immune response upon aging.
Genetic and expression analysis of cattle identifies candidate genes in pathways responding to
Trypanosoma congolense
infection
Authors: Noyes Harry , Brass Andy , Obara Isaiah , Anderson Susan , Archibald Alan L. , Bradley Dan G. , Fisher Paul , Freeman Abigail , Gibson John , Gicheru Michael , Hall Laurence , Hanotte Olivier , Hulme Helen , McKeever Declan , Murray Caitriona , Oh Sung Jung , Tate Catriona , Smith Ken , Tapio Miika , Wambugu John , Williams Diana J. , Agaba Morris , Kemp Stephen J.
Published: May 2011

African bovine trypanosomiasis caused by
Trypanosoma
sp., is a major constraint on cattle productivity in sub-Saharan Africa. Some African
Bos taurus
breeds are highly tolerant of infection, but the potentially more productive
Bos indicus
zebu breeds are much more susceptible. Zebu cattle are well adapted for plowing and haulage, and increasing their tolerance of trypanosomiasis could have a major impact on crop cultivation as well as dairy and beef production. We used three strategies to obtain short lists of candidate genes within QTL that were previously shown to regulate response to infection. We analyzed the transcriptomes of trypanotolerant N'Dama and susceptible Boran cattle after infection with
Trypanosoma congolense.
We sequenced EST libraries from these two breeds to identify polymorphisms that might underlie previously identified quantitative trait loci (QTL), and we assessed QTL regions and candidate loci for evidence of selective sweeps. The scan of the EST sequences identified a previously undescribed polymorphism in ARHGAP15 in the Bta2 trypanotolerance QTL. The polymorphism affects gene function in vitro and could contribute to the observed differences in expression of the MAPK pathway in vivo. The expression data showed that TLR and MAPK pathways responded to infection, and the former contained TICAM1, which is within a QTL on Bta7. Genetic analyses showed that selective sweeps had occurred at TICAM1 and ARHGAP15 loci in African taurine cattle, making them strong candidates for the genes underlying the QTL. Candidate QTL genes were identified in other QTL by their expression profile and the pathways in which they participate.
Simple line drawings suffice for functional MRI decoding of natural scene categories
Authors: Walther Dirk B. , Chai Barry , Caddigan Eamon , Beck Diane M. , Fei-Fei Li
Published: May 2011

Humans are remarkably efficient at categorizing natural scenes. In fact, scene categories can be decoded from functional MRI (fMRI) data throughout the ventral visual cortex, including the primary visual cortex, the parahippocampal place area (PPA), and the retrosplenial cortex (RSC). Here we ask whether, and where, we can still decode scene category if we reduce the scenes to mere lines. We collected fMRI data while participants viewed photographs and line drawings of beaches, city streets, forests, highways, mountains, and offices. Despite the marked difference in scene statistics, we were able to decode scene category from fMRI data for line drawings just as well as from activity for color photographs, in primary visual cortex through PPA and RSC. Even more remarkably, in PPA and RSC, error patterns for decoding from line drawings were very similar to those from color photographs. These data suggest that, in these regions, the information used to distinguish scene category is similar for line drawings and photographs. To determine the relative contributions of local and global structure to the human ability to categorize scenes, we selectively removed long or short contours from the line drawings. In a category-matching task, participants performed significantly worse when long contours were removed than when short contours were removed. We conclude that global scene structure, which is preserved in line drawings, plays an integral part in representing scene categories.
Forming giant vesicles with controlled membrane composition, asymmetry, and contents
Authors: Richmond David L. , Schmid Eva M. , Martens Sascha , Stachowiak Jeanne C. , Liska Nicole , Fletcher Daniel A.
Published: May 2011

Growing knowledge of the key molecular components involved in biological processes such as endocytosis, exocytosis, and motility has enabled direct testing of proposed mechanistic models by reconstitution. However, current techniques for building increasingly complex cellular structures and functions from purified components are limited in their ability to create conditions that emulate the physical and biochemical constraints of real cells. Here we present an integrated method for forming giant unilamellar vesicles with simultaneous control over (i) lipid composition and asymmetry, (ii) oriented membrane protein incorporation, and (iii) internal contents. As an application of this method, we constructed a synthetic system in which membrane proteins were delivered to the outside of giant vesicles, mimicking aspects of exocytosis. Using confocal fluorescence microscopy, we visualized small encapsulated vesicles docking and mixing membrane components with the giant vesicle membrane, resulting in exposure of previously encapsulated membrane proteins to the external environment. This method for creating giant vesicles can be used to test models of biological processes that depend on confined volume and complex membrane composition, and it may be useful in constructing functional systems for therapeutic and biomaterials applications.
Ligand-gated diffusion across the bacterial outer membrane
Authors: Lepore Bryan W. , Indic Mridhu , Pham Hannah , Hearn Elizabeth M. , Patel Dimki R. , van den Berg Bert
Published: May 2011

Ligand-gated channels, in which a substrate transport pathway is formed as a result of the binding of a small-molecule chemical messenger, constitute a diverse class of membrane proteins with important functions in prokaryotic and eukaryotic organisms. Despite their widespread nature, no ligand-gated channels have yet been found within the outer membrane (OM) of Gram-negative bacteria. Here we show, using in vivo transport assays, intrinsic tryptophan fluorescence and X-ray crystallography, that high-affinity (submicromolar) substrate binding to the OM long-chain fatty acid transporter FadL from
Escherichia coli
causes conformational changes in the N terminus that open up a channel for substrate diffusion. The OM long-chain fatty acid transporter FadL from
E. coli
is a unique paradigm for OM diffusion-driven transport, in which ligand gating within a β-barrel membrane protein is a prerequisite for channel formation.
Nod-like receptor pyrin domain-containing protein 6 (NLRP6) controls epithelial self-renewal and colorectal carcinogenesis upon injury
Authors: Normand Sylvain , Delanoye-Crespin Anne , Bressenot Aude , Huot Ludovic , Grandjean Teddy , Peyrin-Biroulet Laurent , Lemoine Yves , Hot David , Chamaillard Mathias
Published: May 2011

The colonic epithelium self-renews every 3 to 5 d, but our understanding of the underlying processes preserving wound healing from carcinogenesis remains incomplete. Here, we demonstrate that Nod-like receptor pyrin domain-containing protein 6 (NLRP6) suppresses inflammation and carcinogenesis by regulating tissue repair. NLRP6 was primarily produced by myofibroblasts within the stem-cell niche in the colon. Although NLRP6 expression was lowered in diseased colon, NLRP6-deficient mice were highly susceptible to experimental colitis. Upon injury, NLRP6 deficiency deregulated regeneration of the colonic mucosa and processes of epithelial proliferation and migration. Consistently, absence of NLRP6 accelerated colitis-associated tumor growth in mice. A gene-ontology analysis on a whole-genome expression profiling revealed a link between NLRP6 and self-renewal of the epithelium. Collectively, the integrity of the epithelial barrier is preserved by NLRP6 that may be manipulated to develop drugs capable of preventing adenoma formation in inflammatory bowel diseases.
Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding
Authors: Gao Su , Zhu Guangjing , Gao Xuefei , Wu Donghai , Carrasco Patricia , Casals Núria , Hegardt Fausto G. , Moran Timothy H. , Lopaschuk Gary D.
Published: May 2011

Brain-specific carnitine palmitoyltransferase-1 (CPT-1c) is implicated in CNS control of food intake. In this article, we explore the role of hypothalamic CPT-1c in leptin's anorexigenic actions. We first show that adenoviral overexpression of CPT-1c in hypothalamic arcuate nucleus of rats increases food intake and concomitantly up-regulates orexigenic neuropeptide Y (NPY) and Bsx (a transcription factor of NPY). Then, we demonstrate that this overexpression antagonizes the anorectic actions induced by central leptin or compound cerulenin (an inhibitor of fatty acid synthase). The overexpression of CPT-1c also blocks leptin-induced down-regulations of NPY and Bsx. Furthermore, the anorectic actions of central leptin or cerulenin are impaired in mice with brain CPT-1c deleted. Both anorectic effects require elevated levels of hypothalamic arcuate nucleus (Arc) malonyl-CoA, a fatty acid-metabolism intermediate that has emerged as a mediator in hypothalamic control of food intake. Thus, these data suggest that CPT-1c is implicated in malonyl-CoA action in leptin's hypothalamic anorectic signaling pathways. Moreover, ceramide metabolism appears to play a role in leptin's central control of feeding. Leptin treatment decreases Arc ceramide levels, with the decrease being important in leptin-induced anorectic actions and down-regulations of NPY and Bsx. Of interest, our data indicate that leptin impacts ceramide metabolism through malonyl-CoA and CPT-1c, and ceramide de novo biosynthesis acts downstream of both malonyl-CoA and CPT-1c in mediating their effects on feeding and expressions of NPY and Bsx. In summary, we provide insights into the important roles of malonyl-CoA, CPT-1c, and ceramide metabolism in leptin's hypothalamic signaling pathways.
Discovery of an unusual biosynthetic origin for circular proteins in legumes
Authors: Poth Aaron G. , Colgrave Michelle L. , Lyons Russell E. , Daly Norelle L. , Craik David J.
Published: May 2011

Cyclotides are plant-derived proteins that have a unique cyclic cystine knot topology and are remarkably stable. Their natural function is host defense, but they have a diverse range of pharmaceutically important activities, including uterotonic activity and anti-HIV activity, and have also attracted recent interest as templates in drug design. Here we report an unusual biosynthetic origin of a precursor protein of a cyclotide from the butterfly pea,
Clitoria ternatea
, a representative member of the Fabaceae plant family. Unlike all previously reported cyclotides, the domain corresponding to the mature cyclotide from this Fabaceae plant is embedded within an albumin precursor protein. We confirmed the expression and correct processing of the cyclotide encoded by the
Cter M
precursor gene transcript following extraction from
C. ternatea
leaf and sequencing by tandem mass spectrometry. The sequence was verified by direct chemical synthesis and the peptide was found to adopt a classic knotted cyclotide fold as determined by NMR spectroscopy. Seven additional cyclotide sequences were also identified from
C. ternatea
leaf and flower, five of which were unique. Cter M displayed insecticidal activity against the cotton budworm
Helicoverpa armigera
and bound to phospholipid membranes, suggesting its activity is modulated by membrane disruption. The Fabaceae is the third largest family of flowering plants and many Fabaceous plants are of huge significance for human nutrition. Knowledge of Fabaceae cyclotide gene transcripts should enable the production of modified cyclotides in crop plants for a variety of agricultural or pharmaceutical applications, including plant-produced designer peptide drugs.
Evolutionary origin of a novel gene expression pattern through co-option of the latent activities of existing regulatory sequences
Authors: Rebeiz Mark , Jikomes Nick , Kassner Victoria A. , Carroll Sean B.
Published: May 2011

Spatiotemporal changes in gene expression underlie many evolutionary novelties in nature. However, the evolutionary origins of novel expression patterns, and the transcriptional control elements (“enhancers”) that govern them, remain unclear. Here, we sought to explore the molecular genetic mechanisms by which new enhancers arise. We undertook a survey of closely related
Drosophila
species to identify recently evolved novel gene expression patterns and traced their evolutionary history. Analyses of gene expression in a variety of developing tissues of the
Drosophila melanogaster
species subgroup revealed high rates of expression pattern divergence, including numerous evolutionary losses, heterochronic shifts, and expansions or contractions of expression domains. However, gains of novel expression patterns were much less frequent. One gain was observed for the
Neprilysin-1
(
Nep1
) gene, which has evolved a unique expression pattern in optic lobe neuroblasts of
Drosophila santomea
. Dissection of the
Nep1 cis
-regulatory region localized a newly derived optic lobe enhancer activity to a region of an intron that has accumulated a small number of mutations. The
Nep1
optic lobe enhancer overlaps with other enhancer activities, from which the novel activity was co-opted. We suggest that the novel optic lobe enhancer evolved by exploiting the cryptic activity of extant regulatory sequences, and this may reflect a general mechanism whereby new enhancers evolve.