bluuebunny/crossref_metadata_2025 huggingface dataset:
Perforation of Jejunal Diverticula in Steroids and Nonsteroidal Anti‐Inflammatory Drug Abusers: A Case Series
Authors: Palanivelu Chinnusamy , Rangarajan Muthukumaran , Rajapandian Subbiah , Maheshkumaar Gobi Shanmugam , Madankumar Madhupalayam Velusamy
Published: March 2008

Introduction

Jejunal diverticula are rare lesions, and when complications arise, they pose diagnostic difficulties. Perforation is a common complication resulting in an acute abdomen, although preoperative diagnosis is usually not possible. The “gold standard” for management for patients with complications is surgery. We present a series of patients with perforated jejunal diverticula who were on prolonged treatment with nonsteroidal anti‐inflammatory drugs (NSAIDs) and steroids for Chikungunya fever.

Methods

There were a total of six patients, all of them presenting with perforative peritonitis, with or without shock. Plain abdominal radiogram and ultrasonogram confirmed this, although the exact site of the perforation was not diagnosed preoperatively. All patients underwent exploratory laparotomy and perforated jejunal diverticulum was found. Resection and anastomosis was performed in all cases.

Results

The mean operating time was 113.5 minutes, and the blood loss was not significant. Postoperative course was uneventful except wound infection in two patients. There was no mortality.

Conclusions

Prolonged NSAID and steroid use are known to cause ulceration/perforation of the upper digestive tract and colonic diverticula. This seems to be the most likely cause for the perforation of jejunal diverticula in our series of patients. This view is supported by the absence of inflammation and infiltration of neutrophils on histopathological examination of the diverticula.
Evaluation of Breast Lymphatic Pathways with Indocyanine Green Fluorescence Imaging in Patients with Breast Cancer
Authors: Ogasawara Yutaka , Ikeda Hirokuni , Takahashi Mina , Kawasaki Kensuke , Doihara Hiroyoshi
Published: March 2008

Background

In patients with early breast cancer, sentinel lymph node biopsy (SLNB) has been emerging as a new standard of care. The use of SLNB with a blue dye is convenient and safe, but it requires a high level of technical skill. Recently, an instrument that can provide fluorescence imaging of lymphatic flow has been introduced. In the present study, we analyzed breast lymphatic pathways and discussed its potential as a modality to complement the use of SLNB with a blue dye.

Methods

Thirty‐seven consecutive patients with breast cancer were examined. To obtain fluorescence imaging, an invisible near‐infrared fluorescence imaging system was used. After indocyanine green was subdermally injected in the subareolar site and at two sites around the tumor, the subcutaneous lymphatic drainage pathway (LDP) was observed.

Results

In 27 (72.9%) of the patients, the number of LDP from the periareolar area was one or two. In 21(63.6%) of 33 patients with subdermal injection around the tumor, no LDP was observed from the peritumoral area. Lymphatic connection between the peritumoral area and the periareolar area was observed very frequently (91.7%). In 26 (70.3%) of the patients, multiple routes joined together and only one route was ultimately directed to the axilla. Significant correlation was seen between body mass index (BMI) and the transit time to the axilla after injection (p = 0.0038). Additionally, a significant correlation was seen between the number of LPD from the periareolar area and the distance between detected SLNs and the fluorescence line‐disappearing point (p = 0.034).

Conclusions

This instrument can provide some important information, and can be an available and reliable navigator for SLNB with a blue dye.
Bedside Placement of Removable Vena Cava Filters Guided by Intravascular Ultrasound in the Critically Injured
Authors: Spaniolas Konstantinos , Velmahos George C. , Kwolek Christopher , Gervasini Alice , De Moya Marc , Alam Hasan B.
Published: March 2008

Background

Bedside placement of removable inferior vena cava filters (RVCF) is increasingly used in critically injured patients. The need for fluoroscopic equipment and specialized intensive care unit beds presents major challenges. Intravascular ultrasound (IVUS) eliminates such problems. The objective of the present study was to analyze the safety and feasibility of IVUS‐guided bedside RVCF placement in critically injured patients.

Methods

Between October 2004 and July 2006 47 IVUS‐guided RVCF were placed at the bedside. Medical and trauma registry records were reviewed. Primary outcome was RVCF‐related complications.

Results

The mean patient age was 41 ± 19 years, and the mean Injury Severity Score was 30 ± 12. The right common femoral vein was chosen as the site of access in 40 patients, and the left common femoral vein was the access site in 7 patients. The insertion was performed 3.7 ± 2.5 days after admission. Four patients (8.5%) developed common femoral deep vein thrombosis (DVT) and three (6%) developed a peripheral pulmonary embolism (PE). Complications related to technique were recorded in two patients (4%) and included one misplacement and one access site bleeding with no further associated morbidity. Five patients died during the hospital stay from issues unrelated to RVCF. Forty‐one patients were eligible for follow‐up. Removal of RVCF was offered only to 8 patients and was performed successfully in 4 (10%) at a mean of 130 days (range: 44–183 days).

Conclusions

In this study IVUS‐guided bedside placement of RVCF was feasible but was also associated with complications. Follow‐up was poor, and the rate of removal disappointingly low, underscoring the need for further exploration of the role of RVCF.
Molecular Mechanism of Age‐Specific Hepatic Lipid Accumulation in PPARα (+/−):LDLR (+/−) Mice, an Obese Mouse Model
Authors: Li Yufeng , Sugiyama Eiko , Yokoyama Shin , Jiang Lingling , Tanaka Naoki , Aoyama Toshifumi
Published: March 2008

This study aimed to clarify the molecular mechanisms of age‐specific hepatic lipid accumulation accompanying hyperinsulinemia in a peroxisome proliferator‐activated receptor α (PPARα) (+/−):low‐density lipoprotein receptor (LDLR) (+/−) mouse line. The hepatic fat content, protein amounts, and mRNA levels of genes involved in hepatic lipid metabolism were analyzed in 25‐, 50‐, 75‐ and 100‐week‐old mice. Severe fatty liver was confirmed only in 50‐ and 75‐week‐old mice. The hepatic expression of proteins that function in lipid transport and catabolism did not differ among the groups. In contrast, the mRNA levels and protein amounts of lipogenic enzymes, including acetyl‐coenzyme A carboxylase‐1, fatty acid synthase, and glycerol‐3‐phosphate acyltransferase, enhanced in the mice with fatty liver. Elevated mRNA and protein levels of lipoprotein lipase and fatty acid translocase, which are involved in hepatic lipid uptake, were also detected in mice with fatty liver. Moreover, both protein and mRNA levels of sterol regulatory element‐binding protein‐1 (SREBP‐1), a transcription factor regulating lipid synthesis, had age‐specific patterns similar to those of the proteins described above. Therefore, the age‐specific fatty liver found in the PPARα (+/−):LDLR (+/−) mouse line is probably caused by age‐specific expression of SREBP‐1 and its downstream lipogenic genes, coordinated by the increased uptake of lipids. All of these factors might be affected by age‐specific changes in serum insulin concentration.
From Aquatic to Terrestrial Food Webs: Decrease of the Docosahexaenoic Acid/Linoleic Acid Ratio
Authors: Koussoroplis Apostolos‐Manuel , Lemarchand Charles , Bec Alexandre , Desvilettes Christian , Amblard Christian , Fournier Christine , Berny Philippe , Bourdier Gilles
Published: March 2008

Fatty acid composition of the adipose tissue of six carnivorous mammalian species (European otterLutra lutra, American minkMustela vison, European MinkMustela lutreola, European polecatMustela putorius, stone martenMartes foinaand European wild catFelis silvestris) was studied. These species forage to differing degrees in aquatic and terrestrial food webs. Fatty acid analysis revealed significant differences in polyunsaturated fatty acid composition between species. More specifically, our results underline a gradual significant decrease in the docosahexaenoic acid (DHA)/linoleic acid (LNA) ratio of carnivore species as their dependence on aquatic food webs decreases. In conclusion, the use of the DHA/LNA ratio in long‐term studies is proposed as a potential proxy of changes in foraging behaviour of semi‐aquatic mammals.
Lysine 263 residue of NPM/B23 is essential for regulating ATP binding and B23 stability
Authors: Choi Joung Woo , Lee Sang Bae , Kim Chung Kwon , Lee Kyung-Hoon , Cho Sung-Woo , Ahn Jee-Yin
Published: March 2008

Here, we show that Nucleophsomin/B23 provides lysine 263 as a critical binding site for ATP. Mutagenesis of lysine 263 to asparagine (K263N) disrupts B23 from ATP binding. While B23 WT exclusively localizes to the nucleolus, the B23‐K263N is redistributed from the nucleolus to the nucleoplam. Notably, the K263N mutant is unstable, and displayed rapid degradation. Alteration of K263 induced B23 instability through increased ubiquitination and proteaosomal degradation. Moreover, mutation of K263 impedes the mitogenic effect of B23 in PC12 cells. Thus, K263 is a critical site for ATP binding and required for B23 stability, confining B23 in the nucleolus.
Site‐directed mutagenesis studies of acetylglutamate synthase delineate the site for the arginine inhibitor
Authors: Sancho-Vaello Enea , Fernández-Murga M. Leonor , Rubio Vicente
Published: March 2008

N‐acetyl‐l‐glutamate synthase (NAGS), the first enzyme of bacterial/plant arginine biosynthesis and an essential activator of the urea cycle in animals, is, respectively, arginine‐inhibited and activated. Site‐directed mutagenesis of recombinant Pseudomonas aeruginosa NAGS (PaNAGS) delineates the arginine site in the PaNAGS acetylglutamate kinase‐like domain, and, by extension, in human NAGS. Key residues for glutamate binding are identified in the acetyltransferase domain. However, the acetylglutamate kinase‐like domain may modulate glutamate binding, since one mutation affecting this domain increases the K
m for glutamate. The effects on PaNAGS of two mutations found in human NAGS deficiency support the similarity of bacterial and human NAGSs despite their low sequence identity.
Inhibitory profile of a LEDGF/p75 peptide against HIV‐1 integrase: Insight into integrase–DNA complex formation and catalysis
Authors: Al-Mawsawi Laith Q. , Christ Frauke , Dayam Raveendra , Debyser Zeger , Neamati Nouri
Published: March 2008

A lens epithelium‐derived growth factor (LEDGF)/p75 peptide was evaluated for human immunodeficiency virus type 1 integrase (IN) inhibitory activity. The LEDGF/p75 peptide modestly inhibited IN catalysis and was dependent on IN–DNA assembly. The peptide was also effective at disrupting LEDGF/p75–IN complex formation. We next investigated the activity of the LEDGF/p75 peptide on IN mutant proteins that are unable to catalyze the DNA strand transfer reaction. The LEDGF/p75 peptide displayed an increased potency on these IN proteins, from 5‐fold to greater than 10‐fold, indicating the IN multimeric state greatly influences the peptide inhibitory effects. These results shed light on IN–DNA multimeric formation, and how this process influences the LEDGF/p75–IN interaction.
Peroxynitrite inactivates human‐tissue inhibitor of metalloproteinase‐4
Authors: Donnini Sandra , Monti Martina , Roncone Raffaella , Morbidelli Lucia , Rocchigiani Marina , Oliviero Salvatore , Casella Luigi , Giachetti Antonio , Schulz Richard , Ziche Marina
Published: March 2008

Peroxynitrite, via post‐translational modifications to target proteins, contributes to cardiovascular injury and cancer. Since tissue inhibitor of metalloproteinase‐4 (TIMP‐4), the activity of which is impaired in both pathological conditions, has several amino acid residues susceptible to peroxynitrite, we investigated its role as a potential target of peroxynitrite. Peroxynitrite‐induced nitration and oligomerization of TIMP‐4 attenuated its inhibitory activity against MMP‐2 activity and endothelial or tumor cell invasiveness. Moreover, cell treatment with peroxynitrite promoted the nitration of endogenous TIMP‐4. HPLC/ESI‐MS/MS analysis of peroxynitrite‐treated TIMP‐4 showed modifications at Y114, Y195, Y188 and Y190. In conclusion, TIMP‐4 nitration might be a potential mechanism contributing to cardiovascular disease and cancer.
Mutant p53 targeting by the low molecular weight compound STIMA‐1
Authors: Zache Nicole , Lambert Jeremy M.R. , Rökaeus Nina , Shen Jinfeng , Hainaut Pierre , Bergman Jan , Wiman Klas G. , Bykov Vladimir J.N.
Published: March 2008

Reactivation of mutant p53 in human tumor cells should induce cell death by apoptosis and thus eliminate the tumor. Several small molecules that reactivate mutant p53 have been identified. Here we show that STIMA‐1, a low molecular weight compound with some structural similarities to the previously identified molecule CP‐31398, can stimulate mutant p53 DNA binding in vitro and induce expression of p53 target proteins and trigger apoptosis in mutant p53‐expressing human tumor cells. Human diploid fibroblasts are significantly more resistant to STIMA‐1 than mutant or wild type p53‐carrying tumor cells. STIMA‐1 may provide new insights into possible mechanisms of mutant p53 reactivation and thus facilitate the development of novel anticancer drugs that target mutant p53‐carrying tumors.
Assessing caffeine exposure in pregnant women
Authors: Boylan Sinead M. , Cade Janet E. , Kirk Sara F. L. , Greenwood Darren C. , White Kay L. M. , Shires Susan , Simpson Nigel A. B. , Wild Chris P. , Hay Alastair W. M.
Published: March 2008

Studies on the effects of caffeine on health, while numerous, have produced inconsistent results. One of the most uncertain and controversial effects is on pregnancy outcome. Studies have produced conflicting results due to a number of methodological variations. The major challenge is the accurate assessment of caffeine intake. The aim of the present study was to explore different methods of assessing caffeine exposure in pregnant women. Twenty-four healthy pregnant women from the UK city of Leeds completed both a detailed questionnaire, the caffeine assessment tool (CAT) designed specifically to assess caffeine intake and a prospective 3 d food and drink diary. The women also provided nine saliva samples over two consecutive days for estimation of caffeine and a metabolite (paraxanthine). Caffeine intakes from the CAT and diary showed adequate agreement (intra-class correlation coefficient of 0·5). For saliva caffeine and paraxanthine measures, the between-sample variation (within the same woman) was greater than between-woman and between-day variation. However, there was still adequate agreement between these measures and the CAT. The CAT is a valuable tool that is now being used in a large prospective study investigating caffeine's role in pregnancy outcome.
Primary tracheal tumours: 21 years of experience at Peking Union Medical College, Beijing, China
Authors: Zhengjaiang L , Pingzhang T , Dechao Z , Reddy-Kolanu G , Ilankovan V
Published: March 2008

Objectives:

To review our experience of the treatment of primary tracheal tumours.

Study design:

All medical notes of patients with primary tracheal tumours diagnosed between 1981 and 2002 were retrospectively analysed.

Results:

In this period, 80 patients were diagnosed with primary tracheal malignancy, 48 males and 32 females. The median age was 48 years. Sixty-nine patients had malignant tumours, most commonly adenoid cystic carcinoma (50.7 per cent) or squamous cell carcinoma (30.4 per cent). Fifty-five patients underwent surgery, 30 of whom also received radiotherapy. Twenty-five patients received only radiotherapy. The five-year survival rate for all malignant tumours was 30.5 per cent. The five-year survival rates for adenoid cystic carcinoma and squamous cell carcinoma were 40.2 and 24.6 per cent, respectively. Local recurrence and distant metastases developed in 21 patients (30.4 per cent).

Conclusion:

Primary tracheal tumours are rare and mainly malignant. Surgery is the most effective treatment method. Technical advances allow for safe resection of the tumour with a safe, tension-free anastomosis.
Laryngeal chondritis induced by C3–4 osteophyte following supracricoid laryngectomy with cricohyoidoepiglottopexy: report of two cases
Authors: Seino Y , Nakayama M , Okamoto M , Yokobori S , Takeda M , Miyamoto S
Published: March 2008

Objectives:

We have performed supracricoid laryngectomy with cricohyoidoepiglottopexy or with cricohyoidopexy for tumour (T) stage T2 and T3 laryngeal cancer cases and some T4 cases. We report the clinical symptoms and management, using this technique to avoid complications.

Case report:

Among patients undergoing the procedure, two cases manifested laryngeal chondritis following laryngectomy with cricohyoidoepiglottopexy. This complication was caused by C3–4 cervical osteophytes physically contacting the cricoid cartilage. Laryngeal microlaryngoscopy was performed, which revealed white, necrotic tissue in the posterior wall of the pharynx and persistent oedema of the neoglottis.

Conclusions:

When encountering a patient with an excessive osteophyte formation at the level of C3–4, one needs to take extra precautions when undertaking laryngectomy with cricohyoidoepiglottopexy or with cricohyoidopexy.
Predictors of response to short-term proton pump inhibitor treatment in laryngopharyngeal reflux patients
Authors: Siupsinskiene N , Adamonis K , Toohill R J , Sereika R
Published: March 2008

Objectives:

To assess benefit from one and three months' empirical proton pump inhibitor treatment in patients with suspected laryngopharyngeal reflux, and to define pre-therapy factors which may predict success with short-term proton pump inhibitor treatment.

Study design:

Prospective, open clinical study.

Materials and methods:

One hundred adult out-patients with suspected laryngopharyngeal reflux were enrolled in the study. Laryngopharyngeal reflux patients underwent endoscopy and received omeprazole for three months. Efficacy of treatment was assessed at one and three months. Patients were classified as responders if their total symptom score had improved at least 50 per cent, their videolaryngoscopic score had improved by at least two points, and they were satisfied with the results. Pre-therapy factors assessed for an effect on omeprazole outcomes included: patient demographics, reflux symptoms, videolaryngoscopic scores, endoscopic findings, overall vocal dysfunction degree, self-rated voice handicap index, hospital anxiety and depression scale scores, and general well-being score.

Results:

Fifty-six per cent of patients were classified as responders at one month of treatment; this proportion rose to 92 per cent at three months. Those patients entering the study with a higher heartburn score showed a significant response after one month of omeprazole treatment. Non-responders were found to have significantly more anxiety than responders. Logistic regression analysis revealed these factors, plus the medication dose, as being relevant for faster response prediction. No significant association was found between pre-therapy factors and three-month response to proton pump inhibitor treatment.

Conclusion:

Three months of proton pump inhibitor treatment twice daily is warranted for confirming suspicion of laryngopharyngeal reflux. Baseline anxiety levels and heartburn scores, and the medication dose, may be relevant factors when predicting faster response to proton pump inhibitor treatment in carefully selected patients.
Superior semicircular canal dehiscence syndrome: a new aetiology
Authors: Puwanarajah P , Pretorius P , Bottrill I
Published: March 2008

Objective:

We report what we believe to be a unique aetiology of the superior semicircular canal dehiscence syndrome, a recently described condition in which vestibular imbalance and/or hearing loss results from the loss of continuity of the bone overlying the superior semicircular canals.

Case report:

A 58-year-old woman presented with autophony in the right ear and momentary imbalance when shouting (Tullio phenomenon). Temporal bone computed tomography revealed a defect of the right superior semicircular canal caused by an enlarged superior petrosal sinus receiving drainage from a large cerebellar developmental venous anomaly.

Conclusions:

We review superior semicircular canal dehiscence syndrome and its management, and we discuss common aetiologies, contrasting these with the unusual aetiology presented here. We conclude that superior semicircular canal dehiscence syndrome may present with a solely developmental aetiology, despite presenting late in life.
Implications of deforestation for the abundance of restricted-range bird species in a Costa Rican cloud-forest
Authors: Oostra Vicencio , Gomes Laurens G. L. , Nijman Vincent
Published: March 2008

Central America is a region of great avian diversity, and the highlands of Costa Rica and Panama are particularly rich in endemic bird species. Continuing deforestation has destroyed large parts of the birds' natural habitats in this region. The ability of birds to use non-forest habitats will ultimately determine their vulnerability to further deforestation, and knowledge of their habitat use is therefore essential in planning conservation strategies. We examined the effects of deforestation on the abundance of restricted-range bird species in the southern Costa Rican part of the Talamanca mountain range. We used line-transect distance sampling to obtain densities in forest and non-forest habitats. Most (22/28) restricted-range species were recorded in forest and non-forest. Of 28 restricted-range species, 13 species showed a clear preference for forest and 8 for non-forest, and total numbers were one-and-a-half times higher as high in forest compared with non-forest. Of the 10 most common species, one was more abundant in non-forest and seven were more abundant in forest. We conclude that forest is the primary habitat for the majority of the restricted-range avifauna, and their dependence on forest makes them particularly vulnerable to deforestation. Adequate protection of the forests in these mountains is therefore the best assurance of the long-term survival of these birds.
Camera trapping rare and threatened avifauna in west-central Sumatra
Authors: Dinata Yoan , Nugroho Agung , Achmad Haidir Iding , Linkie Matthew
Published: March 2008

Tropical forests are becoming increasingly degraded and fragmented by logging, which can affect the survival of forest bird species in different ways. In this study, we present avifauna data collected from a monitoring programme in west-central Sumatra that set camera traps in three study areas with different habitat types, levels of degradation and protection status. From 5,990 camera trap-nights, 248 independent bird photographs were recorded, comprising four orders and nine species, including three endemic species. The Great Argus Pheasant (Argusianus argus) was recorded in all study areas and most frequently (n = 202 photographs), followed by the threatened Salvadori's Pheasant (Lophura inornata). The greatest diversity of bird species (five) and abundance index (1.44 bird photographs/100 trap-nights) was recorded from a primary hill-submontane forest site located inside Kerinci Seblat National Park (KSNP) bordering degraded forest in a former logging concession recently repatriated into KSNP. However, inside a primary-selectively logged hill-submontane forest site spread over KSNP and an ex-logging concession, a Sumatran Ground Cuckoo (Carpococcyx viridis) was photographed. This species is noteworthy because prior to this study it had only been documented once since 1916. It is therefore crucial to use the camera trap results to increase the protection status for the ground cuckoo area. This has already happened in the other two study areas, where camera trap data have been used to reclassify the areas as Core Zones, the highest level of protection inside KSNP. This study illustrates how routine monitoring can have wider benefits through recording, and conserving, threatened and endemic non-target species in unexpected habitats that might not otherwise have been surveyed.
The historical and current status of Pink-headed Duck Rhodonessa caryophyllacea in Myanmar
Authors: Tordoff Andrew W. , Appleton Tim , Eames Jonathan C. , Eberhardt Karin , Hla Htin , Ma Ma Thwin Khin , Myo Zaw Sao , Moses Saw , Myo Aung Sein
Published: March 2008

Pink-headed Duck Rhodonessa caryophyllacea is a Critically Endangered species that has not been confirmed in the wild since 1948–1949. Historical records of the species are concentrated in India, although there are also a few from Myanmar. Between 2003 and 2005, BirdLife International and the Biodiversity and Nature Conservation Association (BANCA) conducted a series of field surveys of wetland habitats in the lowlands of Kachin state, an area with a cluster of historical records of the species. These were the first targeted efforts to assess the status of the species in Myanmar. These surveys were complemented by reviews of museum specimens and literature relating to the species in Myanmar. Two specimen records represent very strong evidence that the species occurred in Myanmar historically, although they shed little light on its seasonal status in the country. The surveys conducted by BirdLife International and BANCA were unable to confirm the continued occurrence of Pink-headed Duck in Myanmar. However, they did generate a limited amount of equivocal direct evidence, most notably two possible but unconfirmed sightings. There are several reasons for believing that the species may still persist in the lowlands of Kachin state and, perhaps, elsewhere in Myanmar. Shyness, combined with rarity, possible nocturnal habits and the impenetrability of its habitats, means that the species tended to be under-recorded historically, and may continue to be so currently. Further surveys are required to confirm this.
Genetic erosion and changes in distribution of sorghum (Sorghum bicolor L. (Moench)) landraces in north-eastern Ethiopia
Authors: Shewayrga H. , Jordan D. R. , Godwin I. D.
Published: March 2008

Ethiopia is believed to be the centre of origin and domestication for sorghum, where sorghum remains one of the main staple crops. Loss of biodiversity is occurring at an alarming rate in Ethiopia and crops, including sorghum, have long been recognized as vulnerable to genetic erosion. A major collection of sorghum germplasm was made in 1973 by Gebrekidan and Ejeta from north-eastern Ethiopia. A new collection of landraces was made in 2003, and these were field evaluated at Sirinka in 2004 along with representative samples from the 1973 collection. Farmer surveys and soil and climate surveys were also performed. Preliminary analysis demonstrated that some important landraces have disappeared either locally or regionally in the past 30 years and many other landraces have become marginalized. Landraces which are less preferred in terms of agronomic value and end use, and introductions, have become increasingly important. Late maturing landraces were found to be particularly vulnerable, with a number disappearing altogether. Farmers have become more risk averse, and factors such as declining soil fertility, more frequent drought and unreliable rainfall, and increased pest infestation have contributed to a change in farmer landrace selection. Data are presented on the variability and unique characters of some of the Ethiopian landraces, and implications for conservation are discussed.
Development of core subset for the collection of Chinese cultivated eggplants using morphological-based passport data
Authors: Weihai Mao , Jinxin Yi , Sihachakr Darasinh
Published: March 2008

A total of 1968 accessions of cultivated eggplants, belonging to Solanum melongena and Solanum aethiopicum and procured from the IVC/JAAS (Nanjing) and IVC/ZAAS (Hangzhou), China, were examined for 23 morphological traits, such as characteristics of plant, stems, leaves, flowers, fruits and original geographic information. A comprehensive numerical classification methodology, including two types of genetic distance, viz. Mahalanobis (Ma) distance and Euclidean (Eu) distance; four clustering methods, viz. unweighted pair group average (UPGA), Ward's (W), complete linkage (CL) and single linkage (SL) methods; three sampling strategies, viz. random (R), preferred (P) and deviation (D); and four sampling sizes (10, 15, 20 and 30% of initial collection), was used to divide all accessions into main groups and subgroups for the establishment of candidate collections. The evaluation of these candidate collections showed that a combination of Eu distance, UPGA clustering method, and R or P sampling strategy with sampling size at 15–20% was suitable for establishing the core collection, providing an adequate and representative genetic diversity of the initial collection of the cultivated eggplants.
AFLP-based molecular characterization of Brassica rapa and diversity in Canadian spring turnip rape cultivars
Authors: Warwick S. I. , James T. , Falk K. C.
Published: March 2008

Information on genetic diversity and genetic relationships among taxa of Brassica rapa (n = 10, AA genome) is currently limited. Grown for oil, vegetable and fodder use in Europe and Asia, previous studies have indicated western and eastern groups corresponding to independent centres of origin. This study evaluated patterns and levels of genetic diversity in 93 accessions [includes 25 Agriculture and Agri-Food Canada (AAFC) breeding lines (BL)] of B. rapa based on 307 amplified fragment length polymorphisms (AFLP), testing subspecific separateness and the affiliation of four previously unassigned AA genome species (B. perviridis, B. purpuraria, B. ruvo and B. septiceps). AFLP data revealed three main clusters (I, II, III) corresponding to European (I), Indian (III), and a mixed Asian/European/Indian (II) purported origins of the taxa, with several subclusters observed in I and II. Mean AFLP polymorphism levels for Asian, European, Indian and AAFC-BL accessions were 79, 74, 66 and 62%, respectively. Few of the subspecies formed unique clusters and some, particularly subspecies chinensis and pekinensis, were assigned to several clusters. AFLP-based genetic distance information can be used by breeders to select diverse genotypes for cultivar development and fingerprinting of genotypes/cultivars. For example, a single AFLP primer pair was sufficient to uniquely identify all breeding lines in the AAFC B. rapa breeding programme.
Sub‐lethal Levels of Electric Current Elicit the Biosynthesis of Plant Secondary Metabolites
Authors: Kaimoyo Evans , Farag Mohamed A. , Sumner Lloyd W. , Wasmann Catherine , Cuello Joel L. , VanEtten Hans
Published: March 2008

Many secondary metabolites that are normally undetectable or in low amounts in healthy plant tissue are synthesized in high amounts in response to microbial infection. Various abiotic and biotic agents have been shown to mimic microorganisms and act as elicitors of the synthesis of these plant compounds. In the present study, sub‐lethal levels of electric current are shown to elicit the biosynthesis of secondary metabolites in transgenic and non‐transgenic plant tissue. The production of the phytoalexin (+)‐pisatin by pea was used as the main model system. Non‐transgenic pea hairy roots treated with 30–100 mA of electric current produced 13 times higher amounts of (+)‐pisatin than did the non‐elicited controls. Electrically elicited transgenic pea hairy root cultures blocked at various enzymatic steps in the (+)‐pisatin biosynthetic pathway also accumulated intermediates preceding the blocked enzymatic step. Secondary metabolites not usually produced by pea accumulated in some of the transgenic root cultures after electric elicitation due to the diversion of the intermediates into new pathways. The amount of pisatin in the medium bathing the roots of electro‐elicited roots of hydroponically cultivated pea plants was 10 times higher 24 h after elicitation than in the medium surrounding the roots of non‐elicited control plants, showing not only that the electric current elicited (+)‐pisatin biosynthesis but also that the (+)‐pisatin was released from the roots. Seedlings, intact roots or cell suspension cultures of fenugreek ( Trigonella foenum‐graecum), barrel medic, ( Medicago truncatula), Arabidopsis thaliana, red clover ( Trifolium pratense) and chickpea ( Cicer arietinum) also produced increased levels of secondary metabolites in response to electro‐elicitation. On the basis of our results, electric current would appear to be a general elicitor of plant secondary metabolites and to have potential for application in both basic and commercial research.
A discrete element model for the development of compaction localization in granular rock
Authors: Wang Baoshan , Chen Yong , Wong Teng‐fong
Published: March 2008

A discrete element model was developed to simulate the micromechanics of compaction localization in a granular rock. The rock was modeled as a bonded assembly of circular disks, and seven different distributions of radius were considered. To simulate grain crushing and pore collapse, an intragranular damage mechanism was introduced that allows for the shrinkage of a disk if one of its normal contact stresses attains a critical value. The model captures key attributes of failure mode and damage evolution associated with the brittle‐ductile transition in porous sandstones. Our simulations indicate that the development of discrete compaction bands is promoted in a relatively homogeneous granular aggregate, while diffuse band growth and distributed cataclastic flow are preferred modes of compaction in a more heterogeneous system. To interpret the former result an Eshelby inclusion model was proposed to estimate analytically the local stress perturbations due to pore collapse in a homogeneous aggregate.
The VOL‐CALPUFF model for atmospheric ash dispersal: 1. Approach and physical formulation
Authors: Barsotti S. , Neri A. , Scire J. S.
Published: March 2008

We present a new modeling tool, named VOL‐CALPUFF, that is able to simulate the transient and three‐dimensional transport and deposition of volcanic ash under the action of realistic meteorological and volcanological conditions throughout eruption duration. The new model derives from the CALPUFF System, a software program widely used in environmental applications of pollutant dispersion, that describes the dispersal process in both the proximal and distal regions and also in the presence of complex orography. The main novel feature of the model is its capability of coupling a Eulerian description of plume rise with a Lagrangian representation of ash dispersal described as a series of diffusing packets of particles or puffs. The model is also able to describe the multiparticle nature of the mixture as well as the tilting effects of the plume due to wind action. The dispersal dynamics and ash deposition are described by using refined orography‐corrected meteorological data with a spatial resolution up to 1 km or less and a temporal step of 1 h. The modeling approach also keeps the execution time to a few minutes on common PCs, thus making VOL‐CALPUFF a possible tool for the production of ash dispersal forecasts for hazard assessment. Besides the model formulation, this paper presents the type of outcomes produced by VOL‐CALPUFF, shows the effect of main model parameters on results, and also anticipates the fundamental control of atmospheric conditions on the ash dispersal processes. In the companion paper, Barsotti and Neri present a first thorough application of VOL‐CALPUFF to the simulation of a weak plume at Mount Etna (Italy) with the specific aim of comparing model predictions with independent observations.
The VOL‐CALPUFF model for atmospheric ash dispersal: 2. Application to the weak Mount Etna plume of July 2001
Authors: Barsotti S. , Neri A.
Published: March 2008

Here the application of the VOL‐CALPUFF model by Barsotti et al. to a weak plume erupted from Mount Etna in July 2001 is presented and discussed. The reconstruction of the explosive event was obtained by using high‐resolution weather forecasts, produced by a mesoscale nonhydrostatic model, and volcanic source data coming from observations and analytical studies. The plume rise and atmospheric dispersal models were investigated over 5 d of eruption mostly in terms of column height, aerial ash concentration, and ground deposition. Modeling results are shown as a function of various source conditions and compared to independent observations derived from satellite images and deposit mapping. The application of VOL‐CALPUFF clearly highlights the crucial role played by meteorological conditions in determining dispersal dynamics. Some of the most important effects described by the model are (1) the large wind field influence on the plume height determination and tilting, (2) the contrasting dispersal patterns of ash particles of different sizes, (3) the complex and somehow nonintuitive distribution of ash on the ground resulting in preferential directions of dispersal and quite irregular deposit patterns, and (4) the impossibility to reproduce both the column height and the deposit accumulation pattern by adopting a steady state vent mass flow rate over the investigated 4‐d period due to observed temporal changes in eruption dynamics. Modeling results also suggest the need for further integration of simulation outcomes with remote sensing and field reconstructions on ash dispersal processes in future.
Strength, porosity, and permeability development during hydrostatic and shear loading of synthetic quartz‐clay fault gouge
Authors: Crawford B. R. , Faulkner D. R. , Rutter E. H.
Published: March 2008

The strength and permeability of fault zones must be quantified in order to accurately predict crustal strength and subsurface fluid migration. To this end, we performed experiments on mixtures of fine‐grained quartz and kaolinite incremented at 10 wt% intervals between the two end‐member components (analogues for natural fault gouge) in order to establish their strength and fluid flow properties during hydrostatic and shear loading. Hydrostatically compacted samples exhibited permeability reduction on increasing effective pressures from 5 MPa to 50 MPa, with the rate of reduction displaying strong dependency on the synthetic fault gouge composition. The permeability decreases continuously with increasing kaolinite content. Porosity exhibits a distinct minimum that evolves with increasing effective pressure according to the relative compaction of the quartz and kaolinite end‐members. Porosity evolution with increasing clay content is predicted satisfactorily by a simple ideal packing model. At the highest effective pressure (50 MPa), permeability reduced log‐linearly over 4 orders of magnitude with increasing clay content. Mechanically, sheared gouge samples showed a continuous reduction in frictional strength with increasing clay fraction. Permeability decreased further on shear loading after initial hydrostatic compaction to 50 MPa. This was most evident for the pure quartz end‐member, with two orders of magnitude additional reduction, whereas the clay‐rich samples were reduced only tenfold, mostly before a shear strain of 5. Variation of permeability with both clay content and shear deformation may be adequately described by previously published empirical predictors for fault zone permeability. Clay content has the largest effect on permeability, and shear deformation affects permeability of quartz‐rich gouges more than clay‐rich gouges.
Error characterization of infrared and microwave satellite sea surface temperature products for merging and analysis
Authors: Castro Sandra L. , Wick Gary A. , Jackson Darren L. , Emery William J.
Published: March 2008

The complementary nature of infrared and microwave sea surface temperature (SST) products provides opportunities for merging the data, but significant differences among the products must first be understood and characterized. This paper presents a method for specifying the uncertainty in existing infrared and microwave SST products in terms of available satellite‐derived parameters, explores which environmental and sensor parameters contribute most to the errors, and determines if the derived uncertainty estimates can enable significant reductions in the differences among the SST products. Collocations among the satellite retrievals and SST measurements from buoys are used to derive the error estimates. Simple multidimensional lookup tables expressing the expected bias and standard deviation of individual retrievals as functions of various combinations of parameters provide an effective characterization of the uncertainty suitable for operational applications. Bias adjustments derived from the satellite zenith angle, 11–12 μm brightness temperature difference, and SST for the infrared, and wind speed, water vapor content, and SST for the microwave products significantly reduce the variability of differences both between the satellite products and with buoy observations. Further improvements are possible through inclusion of additional independent corrections based on the climatological SST anomaly and aerosol optical depth. These corrections reduce the monthly rms difference between the products by as much as 42% and reduce differences with independent buoys by as much as 10%. The largest individual corrections are to the infrared data in regions of low SST, but the microwave corrections are more geographically distributed and affect more retrievals.
Hydrogeological system of erosional convergent margins and its influence on tectonics and interplate seismogenesis
Authors: Ranero C. R. , Grevemeyer I. , Sahling H. , Barckhausen U. , Hensen C. , Wallmann K. , Weinrebe W. , Vannucchi P. , von Huene R. , McIntosh K.
Published: March 2008

Fluid distribution in convergent margins is by most accounts closely related to tectonics. This association has been widely studied at accretionary prisms, but at half of the Earth's convergent margins, tectonic erosion grinds down overriding plates, and here fluid distribution and its relation to tectonics remain speculative. Here we present a new conceptual model for the hydrological system of erosional convergent margins. The model is based largely on new data and recently published observations from along the Middle America Trench offshore Nicaragua and Costa Rica, and it is consistent with observations from other erosional margins. The observations indicate that erosional margins possess previously unrecognized distinct hydrogeological systems: Most fluid contained in the sediment pores and liberated by early dehydration reactions drains from the plate boundary through a fractured upper plate to seep at the seafloor across the slope, rather than migrating along the décollement toward the deformation front as described for accretionary prisms. The observations indicate that the relative fluid abundance across the plate‐boundary fault zone and fluid migration influence long‐term tectonics and the transition from aseismic to seismogenic behavior. The segment of the plate boundary where fluid appears to be more abundant corresponds to the locus of long‐term tectonic erosion, where tectonic thinning of the overriding plate causes subsidence and the formation of the continental slope. This correspondence between observations indicates that tectonic erosion is possibly linked to the migration of overpressured fluids into the overriding plate. The presence of overpressured fluids at the plate boundary is compatible with the highest flow rates estimated at slope seeps. The change from aseismic to seismogenic behavior along the plate boundary of the erosional margin begins where the amount of fluid at the fault declines with depth, indicating a control on interplate earthquakes. A previously described similar observation along accreting plate boundaries strongly indicates that fluid abundance exerts a first‐order control on interplate seismogenesis at all types of subduction zones. We hypothesize that fluid depletion with depth increases grain‐to‐grain contact, increasing effective stress on the fault, and modifies fault zone architecture from a thick fault zone to a narrower zone of localized slip.
Photoenhanced uptake of NO2 on mineral dust: Laboratory experiments and model simulations
Authors: Ndour Marieme , D'Anna Barbara , George Christian , Ka Oumar , Balkanski Yves , Kleffmann Jörg , Stemmler Konrad , Ammann Markus
Published: March 2008

Mineral dust contains material such as TiO2 that is well known to have photocatalytic activity. In this laboratory study, mixed TiO2‐SiO2, Saharan dust and Arizona Test Dust were exposed to NO2 in a coated wall flow tube reactor. While uptake in the dark was negligible, photoenhanced uptake of NO2 was observed on all samples. For the mixed TiO2‐SiO2, the uptake coefficients increased with increasing TiO2 mass fraction, with BET uptake coefficients ranging from 0.12 to 1.9 × 10−6. HONO was observed from all samples, with varying yields, e.g., 80% for Saharan dust. Three‐dimensional modeling indicates that photochemistry of dust may reduce the NO2 level up to 37% and ozone up to 5% during a dust event in the free troposphere.
Monitoring twenty‐first century climate using GPS radio occultation bending angles
Authors: Ringer Mark A. , Healy Sean B.
Published: March 2008

Simulations of radio occultation bending angle profiles in transient climate experiments using a state‐of‐the‐art global coupled climate model show a clear signal in bending angle emerging over the first half of the twenty‐first century. The bending angle signal can be related to the predicted changes in the climate over this period in response to increasing greenhouse gas concentrations and is shown to be primarily a combination of three distinct effects: the changing temperature structure of the atmosphere, increased water vapor in the troposphere, and the expansion of the atmosphere due to the warming. Analysis of the predicted trends in the bending angle indicates that the climate change signal in the tropical upper troposphere and lower and middle stratosphere may become distinguishable from natural variability, i.e. “detected”, after approximately ten to sixteen years of measurements. This suggests that such observations may be one of our best prospects for monitoring the evolution of the climate over the coming decades.
Spreading and potential instability of Teide volcano, Tenerife, Canary Islands
Authors: Márquez Alvaro , López Iván , Herrera Raquel , Martín‐González Fidel , Izquierdo Tatiana , Carreño Francisco
Published: March 2008

We analyze the role of low‐strength materials in the potential structural instability related to volcano spreading at the active Teide stratovolcano (Tenerife, Canary Islands). To study the low‐strength materials we took advantage of a network of large tunnels within the volcano, excavated for water supply, which allows the in situ inspection and reconstruction of both volcano and substratum structure. We identified two factors which are potentially important to Teide's instability: 1) a dipping low‐strength substratum breccia layer; and 2) a hydrothermally‐altered weak core inside the volcano. Despite we do not find clear structural evidence for volcano substratum spreading, both Teide topographic shape and the summit faulting are features similar to those accepted as examples of volcano flank spreading over a weak core. The detected asymmetric deformation of the edifice makes the north flank of Teide a strong candidate for a potential failure.