bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidermal Growth Factor Receptor and the Squamous Cell Carcinoma of the Head and Neck
Authors: Nair Sudhir V
Published: May 2011

Epidermal growth factor receptor (EGFR) is over expressed in 80 to 90% of squamous cell carcinomas of the head and neck (HNSCC) and plays a role in its pathogenesis and clinical course. Several EGFR-targeted therapies have therefore been developed and tried in clinical trials in the past decade resulting in the approval of cetuximab, an EGFR monoclonal antibody as a treatment agent for HNSCC by US FDA. Even though, EGFR monotherapy so far does not have a significant effect, cetuximab in combination with radiotherapy has enhanced the overall effect of radiotherapy in these patients without enhancing significantly the overall toxicity. Hence, understanding the mechanisms of resistance and exploring new combination treatments with EGFR targeting agents are important.
Oral Radiation Mucositis: A Short Review
Authors: Gupta Tejpal , Krishnatry Rahul , Nachankar Ankita A , Agarwal Jai Prakash
Published: May 2011

Oral radiation mucositis is one of the debilitating and dose-limiting acute toxicity during (chemo) radiation or for HNC having a major impact on the patient daily functioning, well-being and quality of life. The unplanned interruption of treatment secondary to mucositis may compromise the treatment and the outcomes if not adequately addressed. Recently, the integrated pathophysiological mechanism of radiation injury has been proposed, aiding development of certain targeted therapies for the prevention and treatment of oral mucositis. Although there are currently no approved agents or strategies that can reliably prevent or treat oral mucositis, there are several agents are under investigation and development. This is an exciting juncture in the development of drugs and drug delivery agents for radiation oral mucositis. This review is to have a peep into currently available options at present to optimally know when these agents can be used and what should be the direction of future research to maximize the therapeutic benefit.
Retroauricular Hairline Approach for Excision of Second Branchial Cleft Cysts
Authors: Walvekar Rohan R , LeBert Brad , Weiss Sean R , Johnson Jonas T
Published: May 2011

Objective

To report our preliminary experience with a retroauricular hairline incision (RAHI) for excision of second branchial cleft cysts (SBCC) and to present a relevant literature review.

Study design

Retrospective case series.

Methods

A retrospective chart review was conducted of two consecutive patients diagnosed with SBCC who underwent surgical removal via a RAHI. Relevant demographic, clinicopathological and radiological data were recorded. A web-based search was conducted to identify relevant scientific literature on “retroauricular hairline incision/approach” in order to present a systematic review of current literature.

Results

In both cases, the SBCC (6.0 and 3.8 cm) could be safely excised without major complications. One patient developed a temporary hypoesthesia of earlobe. None of the patients had a postoperative infection, hematoma, spillage of cyst fluid or necrosis of the skin flap. All patients were satisfied with the cosmetic outcome of the procedure (100%). The incisions healed well without any evidence of hair loss or keloid formation.

Conclusion

In conclusion, the RAHI offers an excellent surgical outcome and superior cosmetic result with no proven increased risks to the patients who require surgical excision of a benign SBCC.
Metastatic Implantation of Head and Neck Squamous Cell Cancer at PEG Tube Site Exit— An Unusual Relapse Site: A Case Report and Review of Literature
Authors: Palwe Vijay , Talpatra Kaustav , Mahantshetty Umesh , Viswanathan Seethalaxmi
Published: May 2011

Background

The placement of percutaneous endoscopic gastrostomy (PEG) tubes is a common procedure in patients with head and neck cancer who require adequate nutrition because of the inability to swallow before or after surgery and adjuvant therapies. A potential complication of percutaneous endoscopic gastrostomy tubes is the metastatic spread from the original head and neck tumor to the gastrostomy site.

Methods

This is a case of a 55-year-old male with a (cT4N3M0) stage IV squamous cell carcinoma of the oropharynx who underwent percutaneous endoscopic gastrostomy tube placement prior to commencement of definitive chemoradiation therapy and 7 months thereafter developed metastatic spread to the gastrostomy site. Tumor was treated with radiation therapy. A review of the published literature regarding the subject is done. The pull-through method of gastrostomy tube placement had been used in our patient as well as in the majority of the other cases reviewed in the literature.

Conclusions

There is a small but definite risk for tumor implantation in the gastrostomy site when using the pull technique in patients with active head and neck cancer. The direct implantation of tumor through instrumentation is the most likely explanation for metastasis; however, hematogenous seeding is also a possibility. Careful assessment of the oropharynx and hypopharynx before PEG tube placement and the use of alternative techniques for enteral access in patients with untreated or residual malignancy are recommended to minimize this risk.
Vocal Cord Paralysis Following Percutaneous Embolization of a Vagal Paraganglioma
Authors: Vishal Rao , Chavan Purushottam , Raghavendra KS , Ashok Shenoy M
Published: May 2011

Tumors of the head and neck region that frequently require embolization include meningiomas, paragangliomas and angiofibromas, owing to their rich vascularity. Serious complications following embolization are uncommon. We report an unusual case of vocal cord palsy following embolization.
Branchial Cyst: An Unusual Presentation as Intrathoracic Extension and Hoarseness of Voice
Authors: Singh HP , Kumar Sunil , Kumar Ambrish , Agarwal SP
Published: May 2011

Branchial cleft cysts usually present as a unilateral, fluctuant soft tissue swelling that is localized deep to the anterior border of sternocleidomastoid in the lateral aspect of the neck. They are often noticed late in childhood or early adulthood. It is important that clinical diagnosis and, in some cases, appropriate imaging is performed, so that definitive treatment may be carried out. The authors present an unusual case of a 35-year-old man who presented with hoarseness of voice associated with a lateral neck mass that extended retrosternally.
Continuity from Fetal to Neonatal Behavior: Lessons Learned and Future Challenges
Authors: Stanojevic Milan
Published: May 2011

Understanding the relation between fetal and infant behavior and developmental processes of the brain in different periods of gestation may make achievable the distinction between normal and abnormal brain development as well as the early diagnosis of various structural or functional abnormalities. As the development of the brain is unique and continuing process throughout the gestation and after birth, it is expected that there is also continuity of fetal and neonatal behavior, which is the best functional indicator of developmental processes of the brain.

The aim is to present continuity of the general and other movements from prenatal to postnatal life in fetuses and newborns from low- and high-risk pregnancies.

Epidemiological studies revealed that many neurologically impaired infants belong to low-risk population, which means that they seemed to be developmentally normal as fetuses and as infants, while later in childhood neurological disability was diagnosed. Dyskinetic cerebral palsy (CP) is the dominant type of CP found in term-born, appropriate-for-gestational-age children with severe impairments who have frequently experienced adverse perinatal events. As neuroprotective methods of treatment are available for some infants, simple screening methods could be helpful to detect impaired fetuses early enough in order to avoid developmental catastrophe. It has been clear from postnatal assessment of Prechtl's neonatal general movements (GMs) that it is a better predictor of neurodevelopmental disability than neurological examination. Introduction of two-dimensional (2D) and four-dimensional (4D) ultrasound enabled introduction of GMs assessment to the prenatal period. Kurjak et al conducted a study by 4D ultrasound and confirmed earlier findings made by 2D ultrasonography, that there is behavioral pattern continuity from prenatal to postnatal life. New antenatal neurological screening test has been introduced by Kurjak et al (KANET), which was postnatally followed by postnatal neurological screening assessment according to Amiel-Tison (ATNAT). Although many fetal behavioral studies have been conducted in low- and high-risk pregnancies and KANET has been recently standardized, it is still questionable whether the assessment of continuity from fetal to neonatal behavior could improve ability for early detection of brain pathology.
Mild Fetal Ventriculomegaly: Diagnostic Work-up and Management
Authors: Pinto Vincenzo , Rossi Angela Cristina
Published: May 2011

Mild ventriculomegaly (VM), also defined as “borderline”, is a condition characterized by an atrial width between 10 and 15 mm independently from gestational age.

Fetuses with mild ventriculomegaly require an accurate morphological examination to rule out for associated neural and extraneural anomalies. The percentage of this association is 41%. However, in almost 13% of cases, the associated anomaly is not recognized at the time of the initial presentation. It is important to monitor the atrial width during the third trimester because in 15% of the cases it increases. Most of the cases missed at the first examination have a late onset diseases (migrational disorders, parenchimal damage, hemorrhage, etc). For these conditions MRI may play a useful role.

Maternal serum tests for congenital infections should be performed, since infections may be the cause of mild VM in 1.5% of the cases.

Fetal karyotype should also be evaluated, since chromosomal abnormalities may be associated in 2.8% of the cases of isolated VM.

The counseling in cases of apparently isolated mild VMs focuses on the possibility of neurodevelopmental delay in the surviving infants. The average percentage of neurodevelopmental delay reported in the literature is 10.9%. The possibility of late onset brain anomalies must be considered.

In conclusion, the most important prognostic factors are the association with other abnormalities not detected at the first examination and the progression of the ventricular dilatation.
Controversial Ultrasound Findings in Mid-Trimester Pregnancy
Authors: Ebrashy Alaa
Published: May 2011

US equipment became more and more important for the practicing obstetricians, and the demands for practicing US as part of the antenatal care becomes sometimes routine in certain areas. A lot of US workshops are practiced trying to put the guidelines for using the US in this domain, and every now and then new markers and US signs are added that could have some significance in relation to the fetal outcome.

Here a problem now exists, which is the gap between the ability to detect and the understanding of the significance of these findings, and this of course creates a great deal of improper counseling which leads to anxiety and confusions.

The aim of my lecture is to shed some light on some controversial US signs, like echogenic bowel, renal pyelectasis, cardiac echogenic foci, choroid plexus cyst, club foot, polydactyly, single umbilical artery and mild ventriculomegaly.

First I shall discuss the epidemiology–the pathophysiology, underlying risk for associated chromosomal anomalies and the most important is the significance of these signs, if present alone, so trying to suit out an evidence-based approach to their management and to provide the clinician with all the data that enables him to properly counsel the parents and eliminates the confusion created by the mere detection of these findings.
To Doppler or Not to Doppler: From Doppler Ultrasound to Color Doppler to Doppler in 3D and Beyond
Authors: Zalud Ivica , Goh William
Published: May 2011

This review aims to provide the reader with an update on the present and potential clinical applications in Doppler ultrasound in perinatal medicine. Umbilical artery Doppler plays an important role in the management of intrauterine growth restriction (IUGR) and pre-eclampsia and aids in twin-to-twin transfusion syndrome management while notching in the waveform is a predictor of umbilical cord abnormalities. Middle cerebral artery Doppler reliably detects fetal anemia and may be useful in the assessment of IUGR as well. Abnormal uterine artery Doppler may play a role in predicting growth restriction, hypertensive disorders of pregnancy and preterm delivery. Abnormal ductus venosus waveforms can also be used to predict adverse fetal outcome and may allow for better timing of delivery while umbilical venous pulsations may be a sensitive marker for fetal heart failure in hydropic pregnancies. 3D power Doppler allows better small vessel visualization that is not affected by angle of insonation and has been used to diagnose placental and cord abnormalities. Significant improvements have recently occurred, improving the visualization and evaluation of placental vascularity, resulting from enhancements in delineation of tissue detail through electronic compounding and harmonics as well as enhancements in signal processing of frequency- and/or amplitude-based color Doppler ultrasound. Spatial representation of vascularity can be improved by utilizing 3D processing. Greater sensitivity of 3D Doppler ultrasound to macro- and microvascular flow has provided improved anatomic and physiologic assessment throughout pregnancy. The rapid development of these new ultrasound techniques will continue to enlarge the scope of clinical applications in placental studies. As clinical experience with these new technologies increases and as the technology improves further, it is reasonable to expect that 3D Doppler and 4D ultrasound will be complementary addition to well-established 2D Doppler ultrasound imaging.
Ultrasound and Diagnosis of Fetal Anomalies
Authors: Gliozheni Orion , Sylejmani Selami , Kati Kreston
Published: May 2011

Background

Congenital abnormalities account 20 to 25% of perinatal deaths. Now, many genetic and other disorders can be diagnosed early in pregnancy. Screening examinations during pregnancy are an essential part of prenatal care. Among the various screening tests that are now offered to pregnant women, ultrasound (US) has the broadest diagnostic spectrum. There is no modality that can detect as many abnormalities during pregnancy as US. A priority goal in screening is the early detection of major fetal anomalies, which are defined as malformations that affect fetal viability and/or quality of life. During the past 10 years, some multicentric studies in Europe and USA show the successfulness of US diagnostics in detecting congenital abnormalities, even in women with low-risk pregnancy. The term sonoembryology designates the description of the embryonic anatomy, the normal anatomic relations and the development of abnormalities as visualized by ultrasound. To confirm the presence of normal anatomy or to make the diagnosis of an anomaly, we need knowledge of the normal embryonic development, including the appearance of the normal embryo.

Definition of fetal anomalies

Any deviation from the normal range during morphogenesis, constitutes an anomaly. Major anomalies are malformations that affect viability and/or the quality of life and require intervention, and minor anomalies are malformations that are definitely present, but are minimal and usually have no functional significance (e.g. ear tags).

Incidence data on major congenital anomalies vary considerably, depending on the type of detecting system used. The passive detection system reports 2 to 3% of newborns, meanwhile the active detection system, in which newborns are systematically examined by trained obstetricians, reports the incidence of congenital defects in 7.3% of all newborns.

Etiology

About 20% of anomalies in live-born infants are based on a defective gene, 10% are due to chromosomal abnormalities and 10% are mainly due to exogenous injury to the conceptus. Some 60% of all congenital anomalies are indeterminate or multifactorial causes (hereditary factors and environmental influences).

US can detect about 74% of major birth defects and possibly a higher number, when conducted by a well-trained specialist. We have demonstrated in this paper some fetal anomalies found by US during our practice in Tirana and Prizren. There are some anomalies of the CNS, neural tube defects, anomalies of the head, neck and spine, thoracic and cardiac anomalies, gastrointestinal and urinary tract anomalies as well as some extremities anomalies.

Conclusion

US diagnostic is a very useful method for evaluating the fetal health, fetal anomalies, anomalies of placenta and amniotic fluid as well as umbilical cord.
Advances in Ultrasonic Assessment of Acardiac Twin
Authors: Stamatian Florin , Muresan Daniel , Caracostea Gabriela , Kovacs Tunde
Published: May 2011

The development of an acardiac anomaly, one of the most severe human malformations, is a rare complication unique to monochorionic multiple pregnancies. In this condition, the primary malformation is the lack of a well-defined cardiac structure in one twin (the acardiac twin), which is kept alive by its structurally normal co-twin (the pump twin).

The final diagnosis for a twin pregnancy with an acardiac twin may be established after the 9th week, when the cephalic extremity and limbs can be precisely determined.

Direct signs that lead to the diagnosis of an acardiac twin include the absence of cardiac and fetal movements, difficult visualization of the trunk and cephalic poles, thickening of subcutaneous tissue and the presence of umbilical artery reverse flow towards the acardiac fetus mass. The pump fetus may demonstrate hydramnios, cardiomegaly and heart failure.

Once an acardiac anomaly is diagnosed, both the acardiac and pump twins should be assessed to classify the pregnancy according to prognostic factors based on the size and growth of the acardiac twin and the cardiovascular condition of the pump twin. Assessing the extent of heart damage in the pump fetus is a key step in pregnancy management.

There are two available options, either conservative or interventional, for the management of these pregnancies. Serial ultrasound surveillance is important for detecting any worsening of the condition, which may suggest the need for interventions to optimize the pump-twin's chance for survival.

We performed a retrospective analysis of three cases of monochorionic twin pregnancies diagnosed with a twin reversed arterial perfusion (TRAP) sequence during the first and second trimesters. We compared our data with those offered by a review of the literature.
Multiple Pregnancy under Ultrasound Umbrella
Authors: Mikhailov Anton , Romanovsky Artem
Published: May 2011

Multiple pregnancy care based only on knowledge of fetal number does not satisfy clinical practice any more. Appropriate clinical use of data obtained via skilled and timely ultrasound has been proven to be of great value for reduction of typical complication rate in multiple pregnancy for both fetus and mother. Ultrasonography plays a key role when intrauterine interventions during pregnancy are required. It can be successfully used for both precise prenatal diagnosis of numerous chromosomal and congenital diseases and antenatal treatment of multiple pregnancy-specific complications, so medical professionals should be well-trained and experienced. And it is impossible without everyday clinical work, gaining individual knowledge and skills and being informed on developments and achievements in the best world recognized perinatal centers.
Ultrasound vs MRI in Diagnosis of Fetal and Maternal Complications
Authors: Ljubic Aleksandar , Cetkovic Aleksandar , Mikic Aleksandra Novakov , Stamenkovic Jelena Dukanac , Jovanovic Ida , Opincal Tatjana Stosic , Damnjanovic Dusan
Published: May 2011

Ultrasound is the screening modality of choice for the fetal imaging. However, there are circumstances in which an alternative imaging technique is needed for additional information regarding fetal anatomy and pathology as well as different maternal conditions.

Magnetic resonance imaging (MRI) is being increasingly used as correlative imaging modality in pregnancy because it uses no ionizing radiation, provides excellent soft-tissue contrast, and has multiple planes for reconstruction and large field of view, allowing better depiction of anatomy in fetuses with large or complex anomalies.

In this review, we attempted to identify strengths and weaknesses of each modality both from the literature and our own working experience, and to propose to some practical recommendations on when to use which imaging modality.

Both ultrasonography and MRI are operator-dependant and neither technique obviates the need for thorough knowledge of normal and abnormal anatomy. In early pregnancy, and where repeated assessment is needed, ultrasound has the obvious advantage. In circumstances where ultrasound examination is difficult, as in the obese patient or severe oligohydramnion, better images might be obtained by MRI examination. MRI might also identify early fetal ischemic lesions after an insult, such as maternal trauma or death of a monochorionic co-twin. From the published literature, it would appear that MRI may provide additional diagnostic information to that given by ultrasound in 25 to 55% of cases, which in turn may have influence on parental counseling and/or management of affected pregnancies. Individual circumstances and expertise influence the accuracy of both modalities. Ultrasound and MRI should be performed to the highest possible standard, and the final diagnosis should be made in a multidisciplinary setting.
Volume Ultrasound in Uterine and Tubal Evaluation
Authors: Zvanca Mona , Andrei Cristian
Published: May 2011

After the development of the new technologies and rendering modes, it became possible to acquire valuable diagnostic images of the female genital organs. There appear to be few differences in the diagnostic accuracy of standard 2D vs 3D images in detecting pelvic pathology, but 3D scanning can improve efficiency by reducing scanning time and therefore improving patient throughput. Furthermore, 3D ultrasound is able to rapidly acquire and store ultrasonographic data that can later be retrospectively analyzed with little loss of information. The most important advantage is the visualization of the coronal plane. It is therefore likely that the application of 3D ultrasound scanning will increase in the future for diagnostic purposes, particularly when the purchase cost of ultrasound equipment falls. The purpose of this review is to highlight the benefits of volume ultrasound in evaluation of uterine and tubal pathology.
Echographic Evidence of Follicle Development and Maturation
Authors: Vlaisavljevic Veljko
Published: May 2011

Monitoring of individual follicles during the menstrual cycle demonstrates in a non-invasive way the changes in their number and position during the early and the late follicular phase and the luteal phase. The differences in relations between the follicles near the dominant follicle can be demonstrated with the same technique using 3D reconstruction of the ovary.

Recognition of the follicle growth pattern has a prognostic value for the outcome of assisted reproduction methods. Follicular diameter and changes in growth patterns are more important than follicular wall thickness as parameters having an impact on clinical success.

An increased perifollicular blood flow can be measured in the perifollicular period using color and pulsed Doppler. Automated estimation of blood volume around the ovarian follicles brought a new concept to this area. Results confirm the observation that vascularity around the follicle is intense in the periovulatory period.

From our results we can hypothesize that those follicles containing oocytes able to produce pregnancy have a prominent and more uniform perifollicular vascular network .
Rational Use of TVS/Color and 3D in Evaluating Subfertile Women
Authors: Tomar Sakshi , Rao Jai Prakash , Malhotra Narendra
Published: May 2011

Infertility is defined as the failure to conceive a desired pregnancy after 12 months of unprotected intercourse and affects approximately 10% of married couples. With recent technological development and proper use of medically assisted reproduction techniques, one half of these couples will become pregnant.

More than any other new method, ultrasound has made significant improvements in the modern management of female infertility. Transvaginal sonography provides the reproductive endocrinologists with a tool that cannot only evaluate normal and stimulated cycles but also assist in follicle aspiration and subsequent transfer of the embryo. The addition of color Doppler capabilities to transvaginal probes permits visualization of small intraovarian and endometrial vessels, allowing depiction of normal and abnormal physiologic changes in the ovary and uterus. This article reviews on the assessment of ovarian, uterine and tubal causes of infertility and on the current and future role of color Doppler and three-dimensional ultrasound in the field of reproductive endocrinology.
Ultrasound Education and Research in Developing Countries
Authors: Gilani Syed Amir
Published: May 2011

This experience based study was done to share the experience with the readers of this article as well as with the leaders of the modality in these countries and throughout the world of ultrasound. The need of adequate education and training in ultrasound exists in both industrialized and developing countries. In this study educational and training standards in twenty countries is discussed and it is recommended to start proper programs with global guidelines.
Accuracy of Ultrasound Measurements by Novices: Pixels or Voxels
Authors: Nguyen Tho Quynh , Flores Melanie
Published: May 2011

During the last two decades three-dimensional (3D) ultrasound has become increasingly popular around the world. There have been a great number of research papers studying its feasibility as well as reliability and accuracy. Compared to two-dimensional (2D), 3D ultrasound produces better visualization with minimal probe manipulation. The sonographer performing 2D ultrasound has to mentally assemble crosssectional images of a structure and/or object into a 3D image. In cases with uncertain anatomic orientation less experienced examiners may experience difficulties in envisioning three dimensions of the visualized structure, lesion or organ. Patients and parents are often faced with similar problems. A number of studies have shown that novice operators can efficiently store and interpret the volume data by 3D ultrasound, which may have many positive implications in the practice.
Transvaginal Ultrasonography in Female Infertility Evaluation
Authors: Aflatoonian Abbas , Mashayekhy Mehri
Published: May 2011

Ultrasound has become essential in the diagnosis and management of the infertile female. Transvaginal ultrasonography provides a detailed examination of the uterus and ovaries. Evaluation of the infertile female has become increasingly more detailed in recent years because of technologic advancements as vaginal ultrasonography is the first step in assessment of pelvic infertile female.
Nonlinear response of ozone to precursor emission changes in China: a modeling study using response surface methodology
Authors: Xing J. , Wang S. X. , Jang C. , Zhu Y. , Hao J. M.
Published: May 2011

Abstract. Statistical response surface methodology (RSM) is successfully applied for a Community Multi-scale Air Quality model (CMAQ) analysis of ozone sensitivity studies. Prediction performance has been demonstrated through cross validation, out-of-sample validation and isopleth validation. Sample methods and key parameters, including the maximum numbers of variables involved in statistical interpolation and training samples have been tested and selected through computational experiments. Overall impacts from individual source categories which include local/regional NOx and VOC emission sources and NOx emissions from power plants for three megacities – Beijing, Shanghai and Guangzhou – were evaluated using an RSM analysis of a July 2005 modeling study. NOx control appears to be beneficial for ozone reduction in the downwind areas which usually experience high ozone levels, and NOx control is likely to be more effective than anthropogenic VOC control during periods of heavy photochemical pollution. Regional NOx source categories are strong contributors to surface ozone mixing ratios in three megacities. Local NOx emission control without regional involvement may raise the risk of increasing urban ozone levels due to the VOC-limited conditions. However, local NOx control provides considerable reduction of ozone in upper layers (up to 1 km where the ozone chemistry is NOx-limited) and helps improve regional air quality in downwind areas. Stricter NOx emission control has a substantial effect on ozone reduction because of the shift from VOC-limited to NOx-limited chemistry. Therefore, NOx emission control should be significantly enhanced to reduce ozone pollution in China.
Atmospheric sulfur cycling in the southeastern Pacific – longitudinal distribution, vertical profile, and diel variability observed during VOCALS-REx
Authors: Yang M. , Huebert B. J. , Blomquist B. W. , Howell S. G. , Shank L. M. , McNaughton C. S. , Clarke A. D. , Hawkins L. N. , Russell L. M. , Covert D. S. , Coffman D. J. , Bates T. S. , Quinn P. K. , Zagorac N. , Bandy A. R. , de Szoeke S. P. , Zuidema P. D. , Tucker S. C. , Brewer W. A. , Benedict K. B. , Collett J. L.
Published: May 2011

Abstract. Dimethylsulfide (DMS) emitted from the ocean is a biogenic precursor gas for sulfur dioxide (SO2) and non-sea-salt sulfate aerosols (SO42−). During the VAMOS-Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) in 2008, multiple instrumented platforms were deployed in the Southeastern Pacific (SEP) off the coast of Chile and Peru to study the linkage between aerosols and stratocumulus clouds. We present here observations from the NOAA Ship Ronald H. Brown and the NSF/NCAR C-130 aircraft along ~20° S from the coast (70° W) to a remote marine atmosphere (85° W). While SO42− and SO2 concentrations were distinctly elevated above background levels in the coastal marine boundary layer (MBL) due to anthropogenic influence (~800 and 80 pptv, respectively), their concentrations rapidly decreased west of 78° W (~100 and 25 pptv). In the remote region, entrainment from the free troposphere (FT) increased MBL SO2 burden at a rate of 0.05 ± 0.02 μmoles m−2 day−1 and diluted MBL SO42 burden at a rate of 0.5 ± 0.3 μmoles m−2 day−1, while the sea-to-air DMS flux (3.8 ± 0.4 μmoles m−2 day−1) remained the predominant source of sulfur mass to the MBL. In-cloud oxidation was found to be the most important mechanism for SO2 removal and in situ SO42− production. Surface SO42− concentration in the remote MBL displayed pronounced diel variability, increasing rapidly in the first few hours after sunset and decaying for the rest of the day. We theorize that the increase in SO42− was due to nighttime recoupling of the MBL that mixed down cloud-processed air, while decoupling and sporadic precipitation scavenging were responsible for the daytime decline in SO42−.
Horizontal variability of aerosol optical depth observed during the ARCTAS airborne experiment
Authors: Shinozuka Y. , Redemann J.
Published: May 2011

Abstract. We present statistics on the horizontal variability of aerosol optical depth (AOD) directly measured from the NASA P-3 aircraft. Our measurements during two contrasting phases (in Alaska and Canada) of the ARCTAS mission arguably constrain the variability in most aerosol environments common over the globe. In the Canada phase, which features local emissions, 499 nm AOD has a median relative standard deviation (stdrel,med) of 19 % and 9 % and an autocorrelation (r) of 0.37 and 0.71 over 20 km and 6 km horizontal segments, respectively. In the Alaska phase, which features long-range transport, the variability is considerably lower (stdrel,med = 3 %, r = 0.92 even over 35.2 km). Compared to the magnitude of AOD, its wavelength dependence varies less in the Canada phase, more in the Alaska phase. We translate these findings from straight-line flight tracks into grid boxes and points, to help interpretation and design of satellite remote sensing, suborbital observations and transport modeling.
In-situ observation of Asian pollution transported into the Arctic lowermost stratosphere
Authors: Roiger A. , Schlager H. , Schäfler A. , Huntrieser H. , Scheibe M. , Aufmhoff H. , Cooper O. R. , Sodemann H. , Stohl A. , Burkhart J. , Lazzara M. , Schiller C. , Law K. S. , Arnold F.
Published: May 2011

Abstract. On a research flight on 10 July 2008, the German research aircraft Falcon sampled an air mass with unusually high carbon monoxide (CO), peroxyacetyl nitrate (PAN) and water vapour (H2O) mixing ratios in the Arctic lowermost stratosphere. The air mass was encountered twice at an altitude of 11.3 km, ~800 m above the dynamical tropopause. In-situ measurements of ozone, NO, and NOy indicate that this layer was a mixed air mass containing both air from the troposphere and stratosphere. Backward trajectory and Lagrangian particle dispersion model analysis suggest that the Falcon sampled the top of a polluted air mass originating from the coastal regions of East Asia. The anthropogenic pollution plume experienced strong up-lift in a warm conveyor belt (WCB) located over the Russian east-coast. Subsequently the Asian air mass was transported across the North Pole into the sampling area, elevating the local tropopause by up to ~3 km. Mixing with surrounding Arctic stratospheric air most likely took place during the horizontal transport when the tropospheric streamer was stretched into long and narrow filaments. The mechanism illustrated in this study possibly presents an important pathway to transport pollution into the polar tropopause region.
Simulation of aerosol optical properties over a tropical urban site in India using a global model and its comparison with ground measurements
Authors: Goto D. , Badarinath K. V. S. , Takemura T. , Nakajima T.
Published: May 2011

Abstract. Aerosols have great impacts on atmospheric environment, human health, and earth's climate. Therefore, information on their spatial and temporal distribution is of paramount importance. Despite numerous studies have examined the variation and trends of BC and AOD over India, only very few have focused on their spatial distribution or even correlating the observations with model simulations. In the present study, a three-dimensional aerosol transport-radiation model coupled with a general circulation model. SPRINTARS, simulated atmospheric aerosol distributions including BC and aerosol optical properties, i.e., aerosol optical thickness (AOT), Ångström Exponent (AE), and single scattering albedo (SSA). The simulated results are compared with both BC measurements by aethalometer and aerosol optical properties measured by ground-based skyradiometer and by satellite sensor, MODIS/Terra over Hyderabad, which is a tropical urban area of India, for the year 2008. The simulated AOT and AE in Hyderabad are found to be comparable to ground-based measured ones. The simulated SSA tends to be higher than the ground-based measurements. Both these comparisons of aerosol optical properties between the simulations with different emission inventories and the measurements indicate that, firstly the model uncertainties derived from aerosol emission inventory cannot explain the gaps between the simulations and the measurements and secondly the vertical transport of BC and the treatment of BC-containing particles can be the main issue in the global model to solve the gap.
Atmospheric boundary layer wind profile at a flat coastal site – wind speed lidar measurements and mesoscale modeling results
Authors: Floors R. , Batchvarova E. , Gryning S.-E. , Hahmann A. N. , Peña A. , Mikkelsen T.
Published: May 2011

Abstract. Wind profiles up to 600 m height are investigated. Measurements of mean wind speed profiles were obtained from a novel wind lidar and compared to model simulations from a mesoscale model (WRF-ARW v3.1). It is found that WRF is able to predict the mean wind profile rather well and typically within 1–2 m s−1 to the individual measured values. WRF underpredicts the normalized wind profile, especially for stable conditions. The effect of baroclinicity on the upper part of the wind profile is discussed.
Distribution of typical denitrifying functional genes and diversity of the nirS-encoding bacterial community related to environmental characteristics of river sediments
Authors: Huang S. , Chen C. , Wu Q. , Zhang R. , Yang X.
Published: May 2011

Abstract. Denitrification in river sediments leads to nitrate removal from the aquatic system; therefore, it is necessary to understand functional diversity of denitrifier communities in the system. Sediment samples (0–25 cm depth) were collected from three typical locations along the Pearl River. The real-time PCR approach was used to measure the abundance of nitrate (narG), nitrite (nirS, nirK and nrfA), and nitrous oxide (nosZ) reductase genes from the sediment samples. Assemblages of nirS, nirK and nosZ indicated that complete denitrification occurred in sediment cores, with the greatest number of gene copies from 5–15 cm depth. Dissimilatory nitrate reduction appeared to be important below 15 cm depth, based on increasing gene copies of narG and nrfA with sediment depth. There was a close match (78–94 %) between the nirS sequences recovered from Pearl River sediment and those detected in estuarine and marine sediments as well as active sludge, suggesting that domestic sewage inputs and irregular tides. Canonical correspondence analysis indicated that the spatial distribution of denitrifying bacteria was highly correlated with dissolved inorganic N (DIN: NH4+, NO2
Alternative methods to predict actual evapotranspiration illustrate the importance of accounting for phenology – Part 2: The event driven phenology model
Authors: Kovalskyy V. , Henebry G. M.
Published: May 2011

Abstract. Evapotranspiration (ET) flux constitutes a major component of both the water and energy balances at the land surface. Among the many factors that control evapotranspiration, phenology poses a major source of uncertainty in attempts to predict ET. Contemporary approaches to ET modeling and monitoring frequently summarize the complexity of the seasonal development of vegetation cover into static phenological trajectories (or climatologies) that lack sensitivity to changing environmental conditions. The Event Driven Phenology Model (EDPM) offers an alternative, interactive approach to representing phenology. This study presents the results of an experiment designed to illustrate the differences in ET arising from various techniques used to mimic phenology in models of land surface processes. The experiment compares and contrasts two realizations of static phenologies derived from long-term satellite observations of the Normalized Difference Vegetation Index (NDVI) against canopy trajectories produced by the interactive EDPM trained on flux tower observations. The assessment was carried out through validation of predicted ET against records collected by flux tower instruments. The VegET model (Senay, 2008) was used as a framework to estimate daily actual evapotranspiration and supplied with seasonal canopy trajectories produced by the EDPM and traditional techniques. The interactive approach presented the following advantages over phenology modeled with static climatologies: (a) lower prediction bias in crops; (b) smaller root mean square error in daily ET – 0.5 mm per day on average; (c) stable level of errors throughout the season similar among different land cover types and locations; and (d) better estimation of season duration and total seasonal ET.
Hydrological differentiation and spatial distribution of high altitude wetlands in a semi-arid Andean region derived from satellite data
Authors: Otto M. , Scherer D. , Richters J.
Published: May 2011

Abstract. High Altitude Wetlands of the Andes (HAWA) belong to a unique type of wetland within the semi-arid high Andean region. Knowledge about HAWA has been derived mainly from studies at single sites within different parts of the Andes at only small time scales. On the one hand, HAWA depend on water provided by glacier streams, snow melt or precipitation. On the other hand, they are suspected to influence hydrology through water retention and vegetation growth altering stream flow velocity. We derived HAWA land cover from satellite data at regional scale and analysed changes in connection with precipitation over the last decade. Perennial and temporal HAWA subtypes can be distinguished by seasonal changes of photosynthetically active vegetation (PAV) indicating the perennial or temporal availability of water during the year. HAWA have been delineated within a region of 12 800 km2 situated in the Northwest of Lake Titicaca. The multi-temporal classification method used Normalized Differenced Vegetation Index (NDVI) and Normalized Differenced Infrared Index (NDII) data derived from two Landsat ETM+ scenes at the end of austral winter (September 2000) and at the end of austral summer (May 2001). The mapping result indicates an unexpected high abundance of HAWA covering about 800 km2 of the study region (6 %). Annual HAWA mapping was computed using NDVI 16-day composites of Moderate Resolution Imaging Spectroradiometer (MODIS). Analyses on the relation between HAWA and precipitation was based on monthly precipitation data of the Tropical Rain Measurement Mission (TRMM 3B43) and MODIS Eight Day Maximum Snow Extent data (MOD10A2) from 2000 to 2010. We found HAWA subtype specific dependencies on precipitation conditions. A strong relation exists between perennial HAWA and snow fall (r2: 0.82) in dry austral winter months (June to August) and between temporal HAWA and precipitation (r2: 0.75) during austral summer (March to May). Annual changes in spatial extend of perennial HAWA indicate alterations in annual water supply generated from snow melt.
Effects of freezing on soil temperature, frost propagation and moisture redistribution in peat: laboratory investigations
Authors: Nagare R. M. , Schincariol R. A. , Quinton W. L. , Hayashi M.
Published: May 2011

Abstract. The effects of freezing on soil temperature and water movement were monitored in four peat Mesocosms subjected to bidirectional freezing. Temperature gradients were applied by bringing the Mesocosm tops in contact with sub-zero air temperature while maintaining a continuously frozen layer at the bottom (proxy permafrost). Soil water movement towards the freezing front (from warmer to colder regions) was inferred from soil freezing curves and from the total water content of frozen core samples collected at the end of freezing cycle. This study illustrates how differences in initial water content influence the hydrologic functions of active layer in permafrost terrains covered with thick peat during soil freezing. A substantial amount of water, enough to raise the upper surface of frozen saturated soil within 15 cm of the soil surface at the end of freezing period, appeared to have moved upwards during freezing. Effects of temperature on soil matric potential, at least in the initial freezing period, appear to drive such movement as seen from analysis of soil freezing curves. Vapour movement from warmer to colder regions also appears to contribute in moisture movement. Frost propagation is controlled by latent heat for a long time during freezing. A simple conceptual model describing freezing of an organic active layer initially resembling a variable moisture landscape is proposed based upon the results of this study. The results of this study will help in understanding, and ultimately forecasting, the hydrologic response of wetland-dominated terrain underlain by discontinuous permafrost.
Predictors of Serum Total IgE in a Random Sample of 7–17 Year Old Children
Authors: Strømgaard Sofie , Thomsen Simon Francis , Fenger Mogens , Backer Vibeke
Published: May 2011

Background. There is little knowledge of the causes for raised serum total immunoglobulin E (IgE) in children. We investigated the association between perinatal, socioeconomic, demographic, clinical, paraclinical, and early life factors, and total serum IgE. Methods. In a random sample of 7–17 year old children, data on possible risk factors were collected using a questionnaire and total serum IgE was measured in venous blood. Airway responsiveness to inhaled histamine was measured and skin prick tests were performed using common aeroallergens. Data was analysed using linear regression. Results. Positive skin prick test (P<.001), airway hyperresponsiveness (P=.003), atopic dermatitis (P=.046), and parental predisposition to allergy (P=.047) showed a significant relation to serum total IgE levels. There was no association of smoking to serum total IgE. Conclusions. This study showed a strong positive relationship between markers of the atopic syndrome and serum total IgE levels in children. In contrast to some earlier studies, we did not find a significant relation between smoking status and IgE.
Finite Element Analysis Applied to Dentoalveolar Trauma: Methodology Description
Authors: da Silva B. R. , Moreira Neto J. J. S. , da Silva F. I. , de Aguiar A. S. W.
Published: May 2011

Dentoalveolar traumatic injuries are among the clinical conditions most frequently treated in dental practice. However, few studies so far have addressed the biomechanical aspects of these events, probably as a result of difficulties in carrying out satisfactory experimental and clinical studies as well as the unavailability of truly scientific methodologies. The aim of this paper was to describe the use of finite element analysis applied to the biomechanical evaluation of dentoalveolar trauma. For didactic purposes, the methodological process was divided into steps that go from the creation of a geometric model to the evaluation of final results, always with a focus on methodological characteristics, advantages, and disadvantages, so as to allow the reader to customize the methodology according to specific needs. Our description shows that the finite element method can faithfully reproduce dentoalveolar trauma, provided the methodology is closely followed and thoroughly evaluated.
Relationship between the Effectiveness of Arthrocentesis under Sufficient Pressure and Conditions of the Temporomandibular Joint
Authors: Yura Shinya , Ooi Kazuhiro , Izumiyama Yuri
Published: May 2011

Background. The purpose of this study is to investigate the conditions of the temporomandibular joint relative to the effectiveness of an arthrocentesis-like enforced manipulation technique followed by irrigation under high pressure in patients with closed lock. Methods. We performed arthroscopic examination and manipulation followed by irrigation as the initial treatment in 50 joints with closed lock. Relationship between the effectiveness of the procedure and conditions of the temporomandibular joint was statistically analyzed using multiple regression analysis. Results. Significant inverse correlations were found between the extent of improvement in maximum mouth opening after treatment and the initial maximum opening before treatment. There were no significant correlations between improvement of joint pain at mouth opening and in biting and conditions of the temporomandibular joint. Conclusions. Pathologic conditions of the temporomandibular joint did not have an influence on the efficacy of the technique. This result suggests that this procedure has wider application than conventional arthrocentesis.