bluuebunny/crossref_metadata_2025 huggingface dataset:
Bartholin’s Gland Abscesses Caused by Streptococcus pneumoniae in a Primigravida
Authors: Saeed Nermin Kamal , Al-Jufairi Zainab A
Published: October 2013

Bartholin gland cysts and abscesses are common problems in females during their reproductive time. Majority of Bartholin's gland abscesses described are of polymicrobial nature, but not necessarily involves opportunistic microbes that colonize the perineal region. In this report, we describe a case of Bartholin's abscess caused by Streptococcus pneumoniae in a 25-year-old non-diabetic primigravida.
Urinary Tract Infection Due to Paenibacillus alvei in a Chronic Kidney Disease: A Rare Case Report
Authors: Padhi Sanghamitra , Dash Muktikesh , Sahu Rani , Panda Pritilata
Published: October 2013

Paenibacilli, the Gram positive, aerobic spore bearing bacilli are found normally in the environment. Though these organisms were not known to cause human disease, until recently; few species of this genus have been reported to cause infections in humans. We report here, a case of urinary tract infection in a 60-year-old chronic kidney disease patient due to this rare bacterium. The patient presented with complains of fever, dysuria, and flank pain. Routine and microscopic examination of urine revealed no abnormality except plenty of pus cells and albumin (1+). Bacterial culture showed significant bacteruria and the isolated bacteria was identified to be Paenibacillus alvei based on standard biochemical reactions.
Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis
Authors: Kumar Vasudevan Anil , Nisha Nair , Thachathodiyl Rajesh , Nandakumar Aswathy , Dinesh Kavitha R , Thatcher Eileen , Karim Shamsul , Biswas Raja
Published: October 2013

Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.
Periampullary Adenocarcinoid: Diagnostic Dilemma
Authors: Krishnappa Rashmi , Metikurke Sudha Horakerappa , Honnappa Sridhar , Hosakote Rudresh , Chandrashekar Nagesh Kumar Talkad
Published: October 2013

The growth in periampullary region needs proper evaluation as they can arise from duodenum, pancreas and extra hepatic biliary tree. We have reported a case of adenocarcinoid of duodenum presenting as periampullary growth with obstructive jaundice. Histologically, tumor displayed biphasic pattern, i.e. tubuloglandular architecture with admixed sheets of neuroendocrine cells without pancreas and extra hepatic biliary tree involvement. The adenocarcinoids are of great diagnostic challenges for the pathologist interpreting endoscopic biopsy for the frequent misinterpretation as negative due to their submucosal location or as adenocarcinomas due to tubulo-glandular architecture.
Metastasis in central nervous system: Clinicopathological study with review of literature in a tertiary care center in South India
Authors: Patnayak Rashmi , Jena Amitabh , Vijaylaxmi Bodagala , Lakshmi Amancharla Y. , Prasad BCM , Chowhan Amit Kumar , Rukmangadha N. , Phaneendra Bobbit V. , Reddy Mandyam Kumaraswamy
Published: October 2013

Background: Secondary central nervous system (CNS) tumors are common in Western countries, but in Indian literature, scant data are available. With the advent of newer imaging techniques, the confirmatory histopathological diagnosis has become comparatively easier. Hereby, we have analyzed our data from a single tertiary care center in south India. Materials and Methods: In this retrospective study from January 2000 to December 2010, histopathologically diagnosed secondary CNS tumors were reviewed along with clinical, imaging, and relevant immunohistochemical findings. Meningeal, lymphoproliferative, and myeloproliferative tumors and autopsy data were not included in the study group. Results: There were 40 secondary CNS tumors. Male to female ratio was 2.3:1. Age range was wide (28-75 years). Majority of cases were seen in the fourth and fifth decade. Imaging-wise, (computed tomography and magnetic resonance imaging) majority were single lesions (n = 34, 85%). Most commonly, these single lesions were present in the cerebral hemisphere (n = 20, 50%) followed by cerebellum (n = 10, 25%). Adenocarcinoma accounted for maximum number of cases (n = 25, 62.5%) with lungs being the most common primary. Conclusion: We have noted 25% metastatic adenocarcinomas in cerebellar location, which is higher when compared with available world literature. However, we also encountered a good number of cases (30%) due to unknown primary. Though histopathological examination with use of immunohistochemical markers can reliably distinguish primary from secondary CNS tumors in addition to available clinical and imaging data, particularly in developing countries, still a better work-up with an array of immunohistochemical markers and newer imaging modalities is desirable.
Is human papillomavirus vaccination likely to be a useful strategy in India?
Authors: Gupta Sudeep , Kerkar Rajendra A. , Dikshit Rajesh , Badwe Rajendra A.
Published: October 2013

Two vaccines that protect against infection by some of the oncogenic human papillomavirus (HPV) subtypes have recently been licensed for use in population-based vaccination strategies in many countries. However, these products are being promoted as ‘cervical cancer vaccines’ based on inadequate data. Specifically, there remain several concerns about the duration of immunogenicity, length of follow-up of trial subjects, endpoints chosen in vaccine trials, applicability of trial results to real populations, the safety of these products, and their cost-effectiveness as public health interventions. Furthermore, it is unlikely that vaccination will obviate the need for setting up robust and cost-effective screening programs in countries like India. This article will discuss various aspects of HPV vaccination from a public health perspective, especially from the point of view of its relevance to India and other South Asian countries.
Immunohistochemistry: A diagnostic aid in differentiating primary epithelial ovarian tumors and tumors metastatic to the ovary
Authors: Kriplani Divya , Patel Mandakini M.
Published: October 2013

Introduction: Among cancers of the female genital tract, the incidence of ovarian cancer ranks below only carcinoma of the cervix and the endometrium. Recent years have witnessed significant development in the use of immunohistochemistry in diagnostic ovarian pathology. Materials and Methods: We received 95 specimens and biopsies of primary ovarian neoplasms and neoplasms metastatic to the ovary in a period of 2 years. Of these 30 cases were of the primary surface epithelial neoplasms and seven of metastatic tumors. Discussion: The most common tumors metastasizing to the ovary originate from the gastrointestinal tract followed by the endometrium. We used a panel of six markers including cytokeratin-7 (CK7), CK20, carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), estrogen receptor (ER) and Wilms’ tumor 1 (WT1) to help classify various surface epithelial tumors as well as to differentiate them from tumors metastatic to the ovary. Conclusion: CK7 is the most helpful marker to differentiate primary ovarian carcinoma from metastatic colorectal carcinoma of the ovary. Nearly, 96% of ovarian adenocarcinomas were positive for CK7 in contrast to metastatic colorectal, which showed only 25% positivity. We also found that CK7, CK20 and CEA are useful markers to differentiate primary serous tumors from primary mucinous tumors; however, these are less helpful in differentiating ovarian mucinous adenocarcinomas from colorectal adenocarcinomas metastasizing to the ovaries. WT1 helps in typing primary surface epithelial tumors of the ovary and is also significant in determining whether a serous carcinoma within the ovary is primary or metastatic.
Denosumab: A comprehensive review
Authors: Narayanan Prasad
Published: October 2013

The clinical sequelae from bone metastases, termed skeletal-related events (SREs), are among the most frequent and debilitating complications in patients with advanced cancer. Bone metastases are characterized by pathologically increased osteoclast activity, and accumulating evidence indicates that tumor cells interact within the bone to stimulate the receptor activator of nuclear factor kB (RANK)-RANK ligand (RANKL) pathway. RANKL is an essential mediator of osteoclast formation, function, and survival. Because of the central role of RANKL in cancer-induced bone destruction, the inhibition of RANKL has the potential to result in the reduction of pathologic bone resorption. Denosumab is a fully human monoclonal antibody specific for RANKL that inhibits the formation, activation, and survival of osteoclasts. This in turn decreases bone resorption and reduces cancer-induced bone destruction. In this review, we give an overview of the drug Denosumab with its history, mechanism of action, clinical trial data, adverse effects, and future challenges.
Procalcitonin and quantitative C-reactive protein role in the early diagnosis of sepsis in patients with febrile neutropenia
Authors: Meidani Mohsen , Khorvash Farzin , Abolghasemi Hojat , Jamali Bahareh
Published: October 2013

Background: Neutropenia with fever is a common syndrome in patients with hematologic malignancies who have a high risk of infectious diseases. As early diagnosis of infection in such patients is really important, the aim of this study was to investigate the sensitivity and specificity of procalcitonin (PCT) and C-reactive protein (CRP) in the diagnosis of sepsis in febrile neutropenic patients in a referral malignant care center of Isfahan in 2010-2011. Materials and Methods: In this analytical cross-sectional study, all the febrile neutropenic patients who were admitted in the referral malignant care center in 2010-2011 were evaluated. The data from every individual, including sex, age, admission time, and duration of fever before taking antibiotics were collected. Sixty-four subjects were involved in the study. Blood samples of the subjects were obtained and the levels of PCT, CRP, Absolute neutrophil count (ANC), and white blood cell count were measured, and blood cultures were obtained. According to the test results, the 64 subjects were divided into two groups including patients with sepsis and without sepsis. Results: Mean value of PCT in the sepsis group was 28.65 ± 2.68 and in the non-sepsis group was 2.48 ± 0.66, with a P value of 0.000. In case of CRP, the sepsis group had a mean of 159.48 ± 9.73 and the non-sepsis group had a mean of 126.17 ± 10.63 (P = 0.015). Sensitivity and specificity were analyzed by using receiver operating characteristic (ROC) curve and were found to be 92.5% and 97.3%, respectively, for PCT and 70.5% and 42.1%, respectively, for CRP. Conclusion: PCT can be considered as a predictive factor and a diagnostic marker for the diagnosis of sepsis in febrile neutropenic patients.
Clinical challenges: Myeloma and concomitant type 2 diabetes
Authors: Ali Mohamed Ahmed , Ahmed Yasar A , Ibrahim Abubaker
Published: October 2013

Multiple myeloma is a malignant plasma cell disorder that accounts for approximately 10% of all hematological cancers. It is characterized by accumulation of clonal plasma cells, predominantly in the bone marrow. The prevalence of type 2 diabetes is increasing; therefore, it is expected that there will be an increase in the diagnosis of multiple myeloma with concomitant diabetes mellitus. The treatment of multiple myeloma and diabetes mellitus is multifaceted. The coexistence of the two conditions in a patient forms a major challenge for physicians.
Oncological safety of immediate rectus abdominis myocutaneous breast reconstruction in patients with locally advanced disease (stage IIb and III)
Authors: Mir Mushtaq , Shahdhar Muddassir , Ganaie Khurshid , Syed Quibtiya
Published: October 2013

Background: The management of locally advanced (Stage IIb and III) breast cancer is challenging. It often includes multimodal treatment with systemic therapy and/or radiation therapy and surgery. Immediate breast reconstruction has not traditionally been performed in these patients. We review the results of immediate rectus abdominis musculo-cutaneous (TRAM/VRAM) flap in 60 patients treated for Stage IIb and III breast cancer. Materials and Methods: Data were collected prospectively on 60 patients diagnosed with Stage IIb (32 patients) and Stage III (28 patients) breast cancer between May 2008 and May 2012. All patients had mastectomy and immediate rectus abdominis myocutaneous reconstruction (TRAM in 40 patients and VRAM in 20 patients). All patients received primary systemic therapy, and all patients received postoperative radiotherapy to the operative site. Results: Mean age was 40.13 (range 28-53) years, mean hospital stay was 8.86 days and mean follow-up for the group was 28 months. Neither of them developed local disease recurrence in the operative site till the last follow-up. Eight (13.3%) patients had some delay in chemo-radiation therapy due to flap-related complications. Flap-related complications were present in eight patients (partial flap failure in four and superficial skin necrosis in four). There was no adverse effect of chemo-radiation therapy on reconstructed breast. Conclusion: Immediate TRAM/VRAM breast reconstruction for locally advanced breast cancer is not associated with a significant delay in adjuvant therapy or an increased risk of local relapse. Radiation therapy can be delivered to the reconstructed breast when indicated without difficulty. Breast reconstruction facilitates surgical resection of locally advanced breast cancer with primary closure and should be considered if the patient desires immediate breast reconstruction.
Dermatofibrosarcoma protuberans: Role of wide local excision
Authors: Hamid Raashid , Hafeez Aadil , Darzi Ashraf M. , Zaroo Inam , Owais Habib , Akhter Afrozah
Published: October 2013

Objectives: The main objective of the present study was to study the outcome of surgical treatment of dermatofibrosarcoma protuberans. Materials and Methods: This study included 45 patients both retrospective and prospective from December 1995 to December 2010. Results: Out of 45 patients, 30 were males and 15 females with the male to female ratio of 2:1. Mean age of presentation was 38.4 + 13.2 years. Commonest mode of presentation was raised firm multinodular lesion with fixity to overlying skin. Site distribution was 42.22% trunk, 57.88% extremities and head and neck. None of the patients had lymph node involvement All patients underwent wide local excision. On histological examination, 8 patients had positive margins. Overall recurrence rate was 22.22%. (please clarify what is the difference between the rate of recurrence following surgery and the overall recurrence rate) Only 2 patients developed metastasis to lungs in the course of their follow‑up. Out of 45 patients, 35 remained recurrence free over a varying period of 5 months to 13 years (mean 68 months). Ten patients developed one or more local recurrences. Average time from initial treatment to recurrence was 32 months. All patients with recurrent tumors were subjected to salvage treatment, i.e., re‑excision. Average recurrence‑free period was 36 + 44 months within a mean follow‑up of 68 months. Conclusion: Because of the potential of local recurrence, therapy for DFSP should be directed toward adequate local excision of the primary lesion. Minimal resection should include a surrounding margin, comprising 3-cm margin of normal skin and removal of underlying deep fascia. Compromising on margins invites higher chances of local recurrence.
Characteristics of Mild Dengue Virus Infection in Thai Children
Authors: Yoon In-Kyu , Srikiatkhachorn Anon , Hermann Laura , Buddhari Darunee , Scott Thomas W. , Jarman Richard G. , Aldstadt Jared , Nisalak Ananda , Thammapalo Suwich , Bhoomiboonchoo Piraya , Mammen Mammen P. , Green Sharone , Gibbons Robert V. , Endy Timothy P. , Rothman Alan L.
Published: October 2013

A four-year longitudinal cohort and geographic cluster study in rural Thailand was conducted to characterize the clinical spectrum of dengue virus (DENV) infection. Symptomatic DENV infections in the cohort were detected by active school absence–based surveillance that triggered cluster investigations around ill cohort children. Data from 189 cohort children with symptomatic DENV infection and 126 contact children in the clusters with DENV infection were analyzed. Of infected contacts, only 19% were asymptomatic; 81% were symptomatic, but only 65.9% reported fever. Symptom-based case definitions were unreliable for diagnosis. Symptomatic infections in contacts were milder with lower DENV RNA levels than the cohort. Infections in contacts with fever history were more likely to have detectable DENV RNA than infections without fever history. Mild infections identified by cluster investigations account for a major proportion of all DENV infections. These findings are relevant for disease burden assessments, transmission modeling, and determination of vaccine impact.
Secondary organic aerosol formation during June 2010 in Central Europe: measurements and modelling studies with a mixed thermodynamic-kinetic approach
Authors: Langmann B. , Sellegri K. , Freney E.
Published: October 2013

Abstract. Until recently secondary organic carbon (SOC) aerosol mass concentrations have been systematically underestimated by three-dimensional atmospheric-chemistry-aerosol models. With a newly proposed concept of aging of organic vapours more realistic model results for organic carbon aerosol mass concentrations could be achieved. Applying a mixed thermodynamic-kinetic approach for SOC aerosol formation shifted the aerosol size distribution towards particles in the cloud condensation nuclei size range, thereby emphasising the importance of SOC aerosol formation schemes for modelling realistic cloud and precipitation formation. The additional importance of hetero-molecular nucleation between H2SO4 and organic vapours remains to be evaluated in three-dimensional atmospheric-chemistry-aerosol models. Here a case study is presented focusing on Puy-de-Dôme, France in June 2010. Even though nucleation events at Puy-de-Dôme were rare during the chosen period of investigation a weak event in the boundary layer could be reproduced by the model when nucleation of low-volatile secondary organic vapour is included. Differences in the model results with and without nucleation of organic vapour are visible in the lower free troposphere over several days of the period. Taking into account nucleation of organic vapour leads to an increase in accumulation mode particles due to coagulation of nucleation and aitken mode particles. Moreover, the measurements indicate a considerable increase in SOC aerosol mass concentration during the measurement campaign, which could be reproduced by modelling using a simplified thermodynamic-kinetic approach for SOC aerosol formation and increased biogenic VOC precursor emissions. Comparison with a thermodynamic SOC aerosol formation approach shows a huge improvement in modelled SOC aerosol mass concentration with the thermodynamic-kinetic approach for SOC aerosol formation and a slight improvement of modelled particle size distribution.
Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution
Authors: Fischer E. V. , Jacob D. J. , Yantosca R. M. , Sulprizio M. P. , Millet D. B. , Mao J. , Paulot F. , Singh H. B. , Roiger A.-E. , Ries L. , Talbot R. W. , Dzepina K. , Pandey Deolal S.
Published: October 2013

Abstract. Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs), is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30%), acetone (7%), and a suite of other isoprene and terpene oxidation products (19%). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37%) and alkanes (14%). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.
A fast method for the retrieval of integrated longwave and shortwave top-of-atmosphere upwelling irradiances from MSG/SEVIRI (RRUMS)
Authors: Vázquez-Navarro M. , Mayer B. , Mannstein H.
Published: October 2013

Abstract. A new Rapid Retrieval of Upwelling irradiances from MSG/SEVIRI (RRUMS) is presented. It has been developed to observe the top-of-atmosphere irradiances of small scale and rapidly changing features that are not sufficiently resolved by specific Earth radiation budget sensors. Our retrieval takes advantage of the spatial and temporal resolution of MSG/SEVIRI and provides outgoing longwave and reflected shortwave radiation only by means of a combination of SEVIRI channels. The longwave retrieval is based on a simple linear combination of brightness temperatures from the SEVIRI infrared channels. The shortwave retrieval is based on a neural network that requires as input the visible and near-infrared SEVIRI channels. Both LW and SW algorithms have been validated by comparing their results with CERES and GERB irradiance observations. While being less accurate than their dedicated counterparts, the SEVIRI-based methods have two major advantages compared to CERES and GERB: their higher spatial resolution and the better temporal resolution. With our retrievals it is possible to observe the radiative effect of small-scale features such as cumulus clouds, cirrus clouds, or aircraft contrails. The spatial resolution of SEVIRI is 3 km × 3 km in the sub-satellite point, remarkably better than that of CERES (20 km) or GERB (45 km). The temporal resolution is 15 min (5 min in the Rapid-Scan mode), the same as GERB, but significantly better than that of CERES which, being on board of a polar orbiting satellite, has a temporal resolution as low as 2 overpasses per day.
Retrieval of aerosol single-scattering albedo and polarized phase function from polarized sun-photometer measurements for Zanjan's atmosphere
Authors: Bayat A. , Khalesifard H. R. , Masoumi A.
Published: October 2013

Abstract. The polarized phase function of atmospheric aerosols has been investigated for the atmosphere of Zanjan, a city in northwest Iran. To do this, aerosol optical depth, Ångström exponent, single-scattering albedo, and polarized phase function have been retrieved from the measurements of a Cimel CE 318-2 polarized sun-photometer from February 2010 to December 2012. The results show that the maximum value of aerosol polarized phase function as well as the polarized phase function retrieved for a specific scattering angle (i.e., 60°) are strongly correlated (R = 0.95 and 0.95, respectively) with the Ångström exponent. The latter has a meaningful variation with respect to the changes in the complex refractive index of the atmospheric aerosols. Furthermore the polarized phase function shows a moderate negative correlation with respect to the atmospheric aerosol optical depth and single-scattering albedo (R = −0.76 and −0.33, respectively). Therefore the polarized phase function can be regarded as a key parameter to characterize the atmospheric particles of the region – a populated city in the semi-arid area and surrounded by some dust sources of the Earth's dust belt.
Vertical profile of δ18OOO from middle stratosphere to lower mesosphere derived by retrieval algorithm developed for SMILES spectra
Authors: Sato T. O. , Sagawa H. , Yoshida N. , Kasai Y.
Published: October 2013

Abstract. Ozone is known to have large oxygen isotopic enrichments of about 10 % in the middle stratosphere, however, there have been no reports on ozone isotopic enrichments above the middle stratosphere. We derived an enrichment δ18OOO by a retrieval algorithm specified for the isotopic ratio from the stratosphere to the lower mesosphere based on observations from the Superconducting Submillimeter-Wave Limb–Emission Sounder (SMILES) onboard the International Space Station (ISS). The retrieval algorithm includes (i) an a priori covariance matrix constrained by oxygen isotopic ratios in ozone, (ii) an optimization of spectral windows for ozone isotopomers and isotopologues, and (iii) a common tangent height information for all windows. The δ18OOO obtained by averaging the SMILES measurements at the latitude range of 20° N to 40° N from February to March in 2010 with solar zenith angle <80° was 15% (at 32 km) and the systematic error was estimated to be about 5%. SMILES and past measurements were in good agreement with δ18OOO increasing with altitude between 30 and 40 km. The vertical profile of δ18OOO obtained in this study showed an increase and a decrease with altitude in the stratosphere and mesosphere, respectively. Stratopause is the peak-height of the δ18OOO value, and it rose to 18%. The δ18OOO has a positive correlation with temperature in the range of 220–255 K, indicating that temperature can be a dominant factor to control the vertical profile of δ18OOO in the stratosphere and mesosphere. This is the first report of the observation of δ18OOO over a wide range extending from the stratosphere to the mesosphere.
Seasonal dependence of the longitudinal variations of nighttime ionospheric electron density and equivalent winds at southern midlatitudes
Authors: Luan X. , Dou X.
Published: October 2013

Abstract. It has been indicated that the observed Weddell Sea anomaly (WSA) appeared to be an extreme manifestation of the longitudinal variations in the Southern Hemisphere, since the WSA is characterized by greater evening electron density than the daytime density in the region near the Weddell Sea. In the present study, the longitudinal variations of the nighttime F2-layer peak electron density at southern midlatitudes are analyzed using the observations of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites between 2006 and 2008. It is found that significant longitudinal difference (> 150%) relative to the minimum density at each local time prevails in all seasons, although the WSA phenomenon is only evident in summer under this solar minimum condition. Another interesting feature is that in summer, the maximum longitudinal differences occur around midnight (~ 23:00–00:00 LT) rather than in the evening (19:00–21:00 LT) in the evening, when the most prominent electron density enhancement occurs for the WSA phenomenon. Thus the seasonal–local time patterns of the electron density longitudinal variations during nighttime at southern midlatitudes cannot be simply explained in terms of the WSA. Meanwhile, the variations of the geomagnetic configuration and the equivalent magnetic meridional winds/upward plasma drifts are analyzed to explore their contributions to the longitudinal variations of the nighttime electron density. The maximum longitudinal differences are associated with the strongest wind-induced vertical plasma drifts after 21:00 LT in the Western Hemisphere. Besides the magnetic declination–zonal wind effects, the geographic meridional winds and the magnetic inclination also have significant effects on the upward plasma drifts and the resultant electron density.
Air–sea exchanges of CO2 in the world's coastal seas
Authors: Chen C.-T. A. , Huang T.-H. , Chen Y.-C. , Bai Y. , He X. , Kang Y.
Published: October 2013

Abstract. The air–sea exchanges of CO2 in the world's 165 estuaries and 87 continental shelves are evaluated. Generally and in all seasons, upper estuaries with salinities of less than two are strong sources of CO2 (39 ± 56 mol C m−2 yr−1, positive flux indicates that the water is losing CO2 to the atmosphere); mid-estuaries with salinities of between 2 and 25 are moderate sources (17.5 ± 34 mol C m−2 yr−1) and lower estuaries with salinities of more than 25 are weak sources (8.4 ± 14 mol C m−2 yr−1). With respect to latitude, estuaries between 23.5 and 50° N have the largest flux per unit area (63 ± 101 mmol C m−2 d−1); these are followed by lower-latitude estuaries (23.5–0° S: 44 ± 29 mmol C m−2 d−1; 0–23.5° N: 39 ± 55 mmol C m−2 d−1), and then regions north of 50° N (36 ± 91 mmol C m−2 d−1). Estuaries south of 50° S have the smallest flux per unit area (9.5 ± 12 mmol C m−2 d−1). Mixing with low-pCO2 shelf waters, water temperature, residence time and the complexity of the biogeochemistry are major factors that govern the pCO2 in estuaries, but wind speed, seldom discussed, is critical to controlling the air–water exchanges of CO2. The total annual release of CO2 from the world's estuaries is now estimated to be 0.10 Pg C yr−1, which is much lower than published values mainly because of the contribution of a considerable amount of heretofore unpublished or new data from Asia and the Arctic. The Asian data, although indicating high pCO2, are low in sea-to-air fluxes because of low wind speeds. Previously determined flux values rely heavily on data from Europe and North America, where pCO2 is lower but wind speeds are much higher, such that the CO2 fluxes are higher than in Asia. Newly emerged CO2 flux data in the Arctic reveal that estuaries there mostly absorb rather than release CO2. Most continental shelves, and especially those at high latitude, are undersaturated in terms of CO2 and absorb CO2 from the atmosphere in all seasons. Shelves between 0 and 23.5° S are on average a weak source and have a small flux per unit area of CO2 to the atmosphere. Water temperature, the spreading of river plumes, upwelling, and biological production seem to be the main factors in determining pCO2 in the shelves. Wind speed, again, is critical because at high latitudes, the winds tend to be strong. Since the surface water pCO2 values are low, the air-to-sea fluxes are high in regions above 50° N and below 50° S. At low latitudes, the winds tend to be weak, so the sea-to-air CO2 flux is small. Overall, the world's continental shelves absorb 0.4 Pg C yr−1 from the atmosphere.
Different ocean states and transient characteristics in Last Glacial Maximum simulations and implications for deglaciation
Authors: Zhang X. , Lohmann G. , Knorr G. , Xu X.
Published: October 2013

Abstract. The last deglaciation is one of the best constrained global-scale climate changes documented by climate archives. Nevertheless, understanding of the underlying dynamics is still limited, especially with respect to abrupt climate shifts and associated changes in the Atlantic meridional overturning circulation (AMOC) during glacial and deglacial periods. A fundamental issue is how to obtain an appropriate climate state at the Last Glacial Maximum (LGM, 21 000 yr before present, 21 ka BP) that can be used as an initial condition for deglaciation. With the aid of a comprehensive climate model, we found that initial ocean states play an important role on the equilibrium timescale of the simulated glacial ocean. Independent of the initialization, the climatological surface characteristics are similar and quasi-stationary, even when trends in the deep ocean are still significant, which provides an explanation for the large spread of simulated LGM ocean states among the Paleoclimate Modeling Intercomparison Project phase 2 (PMIP2) models. Accordingly, we emphasize that caution must be taken when alleged quasi-stationary states, inferred on the basis of surface properties, are used as a reference for both model inter-comparison and data model comparison. The simulated ocean state with the most realistic AMOC is characterized by a pronounced vertical stratification, in line with reconstructions. Hosing experiments further suggest that the response of the glacial ocean is dependent on the ocean background state, i.e. only the state with robust stratification shows an overshoot behavior in the North Atlantic. We propose that the salinity stratification represents a key control on the AMOC pattern and its transient response to perturbations. Furthermore, additional experiments suggest that the stratified deep ocean formed prior to the LGM during a time of minimum obliquity (~ 27 ka BP). This indicates that changes in the glacial deep ocean already occur before the last deglaciation. In combination, these findings represent a new paradigm for the LGM and the last deglaciation, which challenges the conventional evaluation of glacial and deglacial AMOC changes based on an ocean state derived from 21 ka BP boundary conditions.
A long-term and reproducible passive microwave sea ice concentration data record for climate studies and monitoring
Authors: Peng G. , Meier W. N. , Scott D. J. , Savoie M. H.
Published: October 2013

Abstract. A long-term, consistent, and reproducible satellite-based passive microwave sea ice concentration climate data record (CDR) is available for climate studies, monitoring, and model validation with an initial operation capability (IOC). The daily and monthly sea ice concentration data are on the National Snow and Ice Data Center (NSIDC) polar stereographic grid with nominal 25 km × 25 km grid cells in both the Southern and Northern Hemisphere polar regions from 9 July 1987 to 31 December 2007. The data files are available in the NetCDF data format at http://nsidc.org/data/g02202.html and archived by the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA) under the satellite climate data record program (http://www.ncdc.noaa.gov/cdr/operationalcdrs.html). The description and basic characteristics of the NOAA/NSIDC passive microwave sea ice concentration CDR are presented here. The CDR provides similar spatial and temporal variability as the heritage products to the user communities with the additional documentation, traceability, and reproducibility that meet current standards and guidelines for climate data records. The data set, along with detailed data processing steps and error source information, can be found at http://dx.doi.org/10.7265/N55M63M1.
How representative are instantaneous evaporative fraction measurements of daytime fluxes?
Authors: Peng J. , Borsche M. , Liu Y. , Loew A.
Published: October 2013

Abstract. Sun-synchronous optical and thermal remote sensing is a promising technique to provide instantaneous ET (evapotranspiration) estimates during satellite overpass. The common approach to extrapolate the instantaneous estimates to values for daily or longer periods relies on the assumption that the EF (evaporative fraction, defined as the ratio of latent heat flux to surface available energy) remains nearly constant during daytime. However, there is still no consensus on the validity of the self-preservation of the EF. We use FLUXNET (a global network of eddy covariance stations) measurements to examine this self-preservation, and the conditions under which it can hold. It is found that the instantaneous EF could represent daytime EF under clear sky conditions, especially between 11:00 and 14:00 LT (local time) for all stations. However, the results show that the EF is more variable during cloudy sky conditions, so that an increase in cloud cover results in an increase in the variability of the EF during daytime.
Virtual water trade and development in Africa
Authors: Konar M. , Caylor K. K.
Published: October 2013

Abstract. A debate has long existed on the relationships between human population, natural resources, and development. Recent research has expanded this debate to include the impacts of trade; specifically, virtual water trade, or the water footprint of traded commodities. We conduct an empirical analysis of the relationships between virtual water trade, population, and development in Africa. We find that increases in virtual water imports do not lead to increases in population growth nor do they diminish human welfare. We establish a new index of virtual water trade openness and show that levels of undernourishment tend to fall with increased values of virtual water trade openness. Countries with small dam storage capacity obtain a higher fraction of their agricultural water requirements from external sources, which may indicate implicit "infrastructure sharing" across nations. Globally, increased crop exports tend to correlate with increased crop water use efficiency, though this relationship does not hold for Africa. However, internal African trade is much more efficient in terms of embodied water resources than any other region in the world. Thus, internal African trade patterns may be compensating for poor internal production systems.
Climate change, vegetation restoration and engineering as a 1:2:1 explanation for reduction of suspended sediment in southwest China
Authors: Ma X. , Lu X. , van Noordwijk M. , Xu J. , Li J.
Published: October 2013

Abstract. Suspended sediment transport in rivers is controlled by terrain, climate and human activities. These variables affect hillslope and riverbank erosion at the source, transport velocities and sedimentation opportunities in the river channel, and entrapment in reservoirs. The relative importance of those factors varies with context but correct attribution is important for policy debates. We analyzed data from the Kejie watershed in the upper Salween, where a combination of land cover change (reforestation, soil and water conservation measures) and river channel engineering (sand mining and check dam construction) interact with a changing climate. Long-term records (1971–2010) of river flow and suspended sediment loads were combined with five land use maps from 1974, 1991, 2001, 2006 and 2009. Average annual sediment yield decreased from 13.7 t ha−1 yr−1 to 8.3 t ha−1 yr−1 between the 1971–1985 and 1986–2010. A distributed hydrological model (Soil and Water Assessment Tools, SWAT) was set up to simulate the sediment sourcing and transport process. By recombining land use and climate data for the two periods in model scenarios, the contribution of these two factors could be assessed with engineering effects derived from residual measured minus modeled transport. Overall 46% of the decrease was due to from land use and land cover change, 25% to climate change to a milder rainfall regime, 25% to engineering measures, and 4% to simulation bias. Mean annual suspended sediment yield decreased exponentially with the increase of forest cover. We discuss the implications for future soil and water conservation initiatives in China.
An objective rationale for the choice of regularisation parameter with application to global multiple-frequency S-wave tomography
Authors: Zaroli C. , Sambridge M. , Lévêque J.-J. , Debayle E. , Nolet G.
Published: October 2013

Abstract. In a linear ill-posed inverse problem, the regularisation parameter (damping) controls the balance between minimising both the residual data misfit and the model norm. Poor knowledge of data uncertainties often makes the selection of damping rather arbitrary. To go beyond that subjectivity, an objective rationale for the choice of damping is presented, which is based on the coherency of delay-time estimates in different frequency bands. Our method is tailored to the problem of global multiple-frequency tomography (MFT), using a data set of 287 078 S-wave delay times measured in five frequency bands (10, 15, 22, 34, and 51 s central periods). Whereas for each ray path the delay-time estimates should vary coherently from one period to the other, the noise most likely is not coherent. Thus, the lack of coherency of the information in different frequency bands is exploited, using an analogy with the cross-validation method, to identify models dominated by noise. In addition, a sharp change of behaviour of the model ℓ∞-norm, as the damping becomes lower than a threshold value, is interpreted as the signature of data noise starting to significantly pollute at least one model component. Models with damping larger than this threshold are diagnosed as being constructed with poor data exploitation. Finally, a preferred model is selected from the remaining range of permitted model solutions. This choice is quasi-objective in terms of model interpretation, as the selected model shows a high degree of similarity with almost all other permitted models (correlation superior to 98% up to spherical harmonic degree 80). The obtained tomographic model is displayed in the mid lower-mantle (660–1910 km depth), and is shown to be compatible with three other recent global shear-velocity models. A wider application of the presented rationale should permit us to converge towards more objective seismic imaging of Earth's mantle.
SD-OCT Stages of Progression of Type 2 Macular Telangiectasia in a Patient followed for 3 Years
Authors: Coscas Gabriel , Coscas Florence , Zucchiatti Ilaria , Bandello Francesco , Soubrane Gisele , Souïed Eric
Published: October 2013

Purpose

To describe the natural course of type 2 idiopathic macular telangiectasia (MT) using spectral-domain optical coherence tomography (SD-OCT).

Methods

Analysis of the different stages of progression of type 2 MT during a period of 3 years using multimodal imaging, including SD-OCT correlated with angiographic and autofluorescence images. The analysis of the different steps was obtained initially from the first eye, then successively from the fellow eye when progressive changes appeared.

Results

The earliest visible alteration at SD-OCT was the interruption of the interface between inner segment and ellipsoid (IS/EL) (stage 1). The second stage was characterized by the complete interruption of both IS/EL interface and external limiting membrane (stage 2). At the next step, a wide disruption of the outer nuclear layer was noted (stage 3). The fourth stage showed a complete disorganization of the inner layers with aspect of fusion of the inner retinal layers associated with progressive atrophy of the outer layers (stage 4). Hyper-reflective deposits were found in both the internal and external retinal layers (stage 5). Small intraretinal cystoid spaces appeared in the different retinal layers (stage 6). This last feature was an earlier manifestation of the typical intraretinal cysts that are the well-known OCT appearance of type 2 MT.

Conclusions

We describe the 6 steps of progression from earlier SD-OCT findings that led to a complete disorganization and fusion of the inner layers (probably due to changes in the Müller cells) to the typical intraretinal cysts.
The influence of biohydrohumus on growth and development of garden pansy (Viola x wittrockiana Gams.)
Authors: Żurawik Piotr , Placek Monika
Published: October 2013

In the years 2007–2008, experiments were conducted with four cultivars of garden pansy grown in pots, in media prepared as mixtures of wet shrimp waste (BioHydroHumus) and sphagnum peat at the following volumetric ratios: 2% BioHydroHumus + 98% sphagnum peat, 5% BioHydroHumus + 95% sphagnum peat, 10% BioHydroHumus + 90% sphagnum peat. The Osmocote Exact 5–6 M (15:8:10:3MgO + microelements) fertilizer at the rates of 2.5 and 5.0 g × dm-3 was added to each medium. Sphagnum peat with addition of 5.0 g × dm-3 Osmocote Exact 5–6 M was used as control medium. It was found that BioHydroHumus can be a source of macroelements in the cultivation of garden pansy. It is characterized by alkaline reaction and high total soluble salts. BioHydroHumus used as a component of media affects the quality of cultivated plants. The best results were obtained when BioHydroHumus was used at the rates of 2 and 5%, even if the rate of fertilizer were twice smaller than in control medium. At full flowering, plants grown in medium containing 5% BioHydroHumus were the most branched. Garden pansies cultivated in medium containing 10% BioHydroHumus were characterized by a smaller number of leaves. Plants grown in media with addition of 2 and 5% BioHydroHumus flowered more abundantly in comparison with garden pansies cultivated in medium containing 10% BioHydroHumus, regardless of the rate of fertilizer. However, an ambiguous influence of BioHydroHumus on height and diameter of garden pansy cultivars was found.
Competition between spring barley (Hordeum vulgare L.) and italian ryegrass (Lolium multiflorum Lam.) under different water supply conditions
Authors: Wanic Maria , Jastrzębska Magdalena , Kostrzewska Marta K. , Treder Kinga
Published: October 2013

A pot experiment with an additive design and three series was conducted to test competition between spring barley and Italian ryegrass under different soil moisture conditions. The experimental factors were as follows: 1. type of sowing – mixed sowing and pure sowing; 2. water supply – plants supplied with water to meet their full requirements and 50% water supply reduction. The study covered five phenological development stages (BBCH) of spring barley: emergence (10–13), tillering (22–25), stem elongation (33–37), heading (52–55), and ripening (87–91). The competitive effects were evaluated based on relative yield (RY), relative yield total (RYT), competitive balance (CB), and relative efficiency index (REI). Spring barley and Italian ryegrass competed for resources throughout the growing season. Competition intensity was found to increase until the heading stage, and it decreased towards the end of the growth cycle. More intense competition was observed under reduced water supply. Spring barley dominated over Italian ryegrass from the tillering stage to the ripening stage. In mixed populations, Italian ryegrass captured the available resources more effectively than spring barley from the stem elongation stage until the end of the growing season, particularly in the treatment with optimal water supply.
The effect of reduced rates of crop protection agents and adjuvants on productivity, weed infestation and health of spring barley (Hordeum sativum L.)
Authors: Kwiatkowski Cezary A. , Wesołowski Marian , Harasim Elżbieta , Gawęda, Dorota , Drabowicz Magda
Published: October 2013

A field experiment on the cultivation of spring barley was carried out in the period 2009–2011 at the Experimental Farm in Czesławice (central Lublin region) on grey-brown podzolic soil derived from loess (soil quality class II). The study included 3 rates of herbicides, growth retardant and fungicides (100%, 75% and 50%) as well as different types of adjuvant (oil, surface-active, mineral). Plots without adjuvant were the control treatment. A hypothesis was made that the reduction in rates of crop protection agents by 25–50%, with the simultaneous addition of adjuvants, would allow spring barley productivity to be maintained at a level similar to that obtained under the conditions when recommended rates are applied without adjuvant. It was also assumed that particular types of adjuvant would show different interactions with specific groups of crop protection agents. It has been proved that a rational reduction in rates of crop protection agents is up to a limit of 25%, especially when an adjuvant is added to such reduced rates. This allows spring barley productivity to be maintained at the level obtained after the application of full rates (without adjuvant). But a further reduction in rates of crop protection agents by 50%, in spite of the interaction of adjuvants, results in a significant deterioration of all spring barley yield components, since such conditions lead to increased occurrence of agricultural pests (weeds, fungal diseases) as well as increased crop lodging. Among the group of adjuvants tested in the present experiment, the oil adjuvant Atpolan 80 EC showed the best interaction with crop protection agents used.