bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing-induced strains at solder interfaces in extended semiconductor structures
Authors: Biermann Mark L. , Cassidy Daniel T. , Tien Tran Quoc , Tomm Jens W.
Published: June 2007

The processing-induced strain in unmetallized areas within solder interfaces of packaged, diode laser chips is investigated by spectroscopic methods, namely, degree of polarization of photoluminescence and photocurrent spectroscopy. An unexpected strain component in the unmetallized regions is identified. Based on spectroscopic results used in concert with modeling that employs the finite element method and theoretical results, this strain component is shown to be primarily compressive along the growth direction of the heterostructure used in the laser architecture. This strain component most likely arises due to localized bending of the heterostructure in the unmetallized regions. This example shows how optical spectroscopy can help in analyzing even strains of complex and unknown symmetry.
Probing the indium clustering in InGaAs∕GaAs quantum wells by room temperature contactless electroreflectance and photoluminescence spectroscopy
Authors: Motyka M. , Sęk G. , Kudrawiec R. , Sitarek P. , Misiewicz J. , Wojcik J. , Robinson B. J. , Thompson D. A. , Mascher P.
Published: June 2007

Room temperature contactless electroreflectance (CER) supported by photoluminescence (PL) has been proposed as a fast and nondestructive ex situ technique for testing the effect of atom clustering in quantum wells (QWs). The indium clustering in InGaAs∕GaAs QWs was achieved by increasing the growth temperature. It has been shown that this effect causes significant changes in the spectral response. While the line shape of the GaAs-related CER feature remains unaffected there appear broad resonances similar to those for naturally inhomogeneous ensemble of self-assembled quantum dots instead of sharp and intensive lines characteristic for QWs. Additionally, the PL signal exhibits a quantum-dot-like behavior as well, i.e., strongly broadened Gaussian-like peaks with linear excitation power dependence on their intensity and the occurrence of the state filling effect for high excitation.
Inhomogeneities in Ni∕4H-SiC Schottky barriers: Localized Fermi-level pinning by defect states
Authors: Ewing D. J. , Porter L. M. , Wahab Q. , Ma X. , Sudharshan T. S. , Tumakha S. , Gao M. , Brillson L. J.
Published: June 2007

We investigated arrays of Ni, Pt, or Ti Schottky diodes on n-type 4H-SiC epitaxial layers using current-voltage (I-V) measurements, electron beam induced current (EBIC), polarized light microscopy, x-ray topography, and depth-resolved cathodoluminescence spectroscopy. A significant percentage of diodes (∼7%–30% depending on epitaxial growth method and diode size) displayed “nonideal” or inhomogeneous barrier height characteristics. We used a thermionic emission model based on two parallel diodes to determine the barrier heights and ideality factors of high- and low-barrier regions within individual nonideal diodes. Whereas high-barrier barrier heights increased with metal work function, low-barrier barrier heights remained constant at ∼0.60, 0.85, and 1.05eV. The sources of these nonidealities were investigated with a variety of spectroscopic and imaging techniques to determine the nature and energy levels of the defects. EBIC indicated that clusters of defects occurred in all inhomogeneous diodes. Cathodoluminescence spectra revealed additional peaks in the nonideal diodes at 2.65, 2.40, and 2.20eV, which complement the low-barrier barrier heights. It is proposed that defect clusters act to locally pin the Fermi level, creating localized low-barrier patches, which account for the inhomogeneous electrical characteristics.
Easy and direct method for calibrating atomic force microscopy lateral force measurements
Authors: Liu Wenhua , Bonin Keith , Guthold Martin
Published: June 2007

We have designed and tested a new, inexpensive, easy-to-make and easy-to-use calibration standard for atomic force microscopy (AFM) lateral force measurements. This new standard simply consists of a small glass fiber of known dimensions and Young’s modulus, which is fixed at one end to a substrate and which can be bent laterally with the AFM tip at the other end. This standard has equal or less error than the commonly used method of using beam mechanics to determine a cantilever’s lateral force constant. It is transferable, thus providing a universal tool for comparing the calibrations of different instruments. It does not require knowledge of the cantilever dimensions and composition or its tip height. This standard also allows direct conversion of the photodiode signal to force and, thus, circumvents the requirement for a sensor response (sensitivity) measurement.
Hybrid three-arm coupler with long range surface plasmon polariton and dielectric waveguides
Authors: Liu Fang , Rao Yi , Tang Xuan , Wan Ruiyuan , Huang Yidong , Zhang Wei , Peng Jiangde
Published: June 2007

The characteristics of hybrid three-arm coupler, which consists of the middle long range surface plasmon polariton waveguide and two outside conventional dielectric waveguides, are analyzed numerically with finite element method. Since the middle arm can only transfer the TM mode from one dielectric arm to the other one, this structure is promising for realizing integrated polarization splitter. Compared with the two-arm hybrid coupler, the loss of three-arm hybrid coupler based device can be reduced. Furthermore, different from conventional three-arm dielectric coupler, the authors find that the three-arm hybrid coupler with asymmetric structure can reach a much higher extinction ratio.
Bragg surface wave device based on porous silicon and its application for sensing
Authors: Guillermain E. , Lysenko V. , Orobtchouk R. , Benyattou T. , Roux S. , Pillonnet A. , Perriat P.
Published: June 2007

Results concerning a Bragg surface wave device based on porous silicon and intended for sensing application are reported. Existence of optical surface waves on Bragg structures is experimentally shown. Such device is expected to be very sensitive to the grafting of biological molecules. The authors demonstrate this sensing effect by grafting of amine chemical groups. The optical characterization using m-line spectroscopy shows that the increase of the coupling angle is about 20° after the amine grafting. The authors show that porosity is essential for reaching this high sensitivity.
Piezoelectric responses in poly(vinylidene fluoride/hexafluoropropylene) copolymers
Authors: Neese Bret , Wang Yong , Chu Baojin , Ren Kailiang , Liu Sheng , Zhang Q. M. , Huang Cheng , West James
Published: June 2007

The authors show that a high transverse piezoelectric response with both high piezoelectric d31 (d31=43.1pm∕V) and electromechanical coupling k31 coefficients (k31=0.187), much higher than those in the piezoelectric poly(vinylidene fluoride) and poly(vinylidene fluoride-trifluoroethylene) copolymers, can be obtained in poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] 10wt% copolymers under quasistatic condition. Furthermore, the copolymers also display a higher d31 coefficient compared to the d33 coefficient, which seems to be unusual compared with most other piezopolymers. The experimental data suggest that the origin of the unusual piezoelectric response in these P(VDF-HFP) copolymers originates from a reversible change between a poled α-like structure and β-like structure. The phase change nature also results in a large frequency dispersion of the piezoelectric response and a smaller d31 (=20.5pm∕V) at 50kHz.
Lasing characteristics of ZnxMg1−xO and ZnO:Al epilayers
Authors: Ding C. R. , Li S. W. , Wang H. Z.
Published: June 2007

Optical characteristics of ZnxMg1−xO, ZnO:Al, and ZnO epilayers are investigated. At pulse laser pumping, stimulated emissions are observed in these epilayers. Among them, spectral blueshifts are dependent on the Mg substitution concentration, and the highest lasing photon energy of 3.51eV ever reported is observed in ZnO series materials. Furthermore, experimental results also show that by high concentration Mg substitution, a redshift of the electron-hole plasma stimulated emission is reduced and its efficiency does not decrease with the Mg substitution concentration. These results imply that the lasing frequency of ZnO series materials can be modified by substitution.
Mode structure of the L3 photonic crystal cavity
Authors: Chalcraft A. R. A. , Lam S. , O’Brien D. , Krauss T. F. , Sahin M. , Szymanski D. , Sanvitto D. , Oulton R. , Skolnick M. S. , Fox A. M. , Whittaker D. M. , Liu H.-Y. , Hopkinson M.
Published: June 2007

The authors investigate the multiple confined modes of GaAs L3 photonic crystal air-bridge cavities, using single layers of InAs quantum dots as active internal light sources. Theoretical results for the energies, quality factors, and emission polarizations of the first five modes are compared to experimental data for cavities with lattice periods ranging from 240to270nm. The authors also present in-plane field distributions for each mode. In addition to the well-known quality factor improvement of the fundamental mode, they show that outward displacement of the end-holes selectively redshifts modes with large end-hole-field overlaps, thus reordering the modes.
Crystallite size dependence of the coefficient of thermal expansion of metals
Authors: Kuru Y. , Wohlschlögel M. , Welzel U. , Mittemeijer E. J.
Published: June 2007

The coefficients of thermal expansion (CTEs) of polycrystalline Ni and Cu thin films have been investigated by employing temperature-dependent x-ray diffraction measurements of lattice parameters. Great care has been taken to exclude effects of, in particular, microstructural relaxation and mechanical stresses on the dependences of the lattice parameters on temperature. The CTEs determined in the as-deposited condition, characterized by grain sizes in the range of 25–35nm, are considerably (about 10%) larger than the corresponding literature values of bulk materials. Heat treating the specimens at moderate temperatures induced grain growth and decrease of the crystalline imperfection. After the heat treatment, the CTEs determined for the thin films had reduced considerably and had become equal to (Ni) or approached (Cu) the corresponding literature data for bulk materials.
Impurity-free disordering of InAs∕InP quantum dots
Authors: Barik S. , Fu L. , Tan H. H. , Jagadish C.
Published: June 2007

Impurity-free disordering (IFD) of the InAs quantum dots (QDs) capped with either an InP layer or an InGaAs∕InP bilayer is studied. The samples are coated with a SiO2 or TiO2 dielectric layer followed by rapid thermal annealing at 700, 750, 800, and 850°C for 30s. A large differential energy shift of 157meV is induced by SiO2 in the QDs capped with an InGaAs∕InP bilayer. Contrary to the reported results on the suppression of intermixing of GaAs based QDs by TiO2, the authors find that intermixing of InAs∕InP QDs is promoted by TiO2. X-ray photoelectron spectroscopy depth profiles show that both In and P outdiffuse to a TiO2 layer whereas Ga, In, and P outdiffuse to a SiO2 layer leading to different degrees of intermixing. The results indicate that a group V interstitial diffusion mechanism might be responsible for IFD of InAs∕InP QDs.
Trilayer superlattices: A route to magnetoelectric multiferroics?
Authors: Hatt Alison J. , Spaldin Nicola A.
Published: June 2007

The authors explore computationally the formation of trilayer superlattices as an alternative approach to combining ferroelectricity with magnetism to form magnetoelectric multiferroics. It is found that the contribution to the superlattice polarization from trilayering is small compared to typical polarizations in conventional ferroelectrics, and the switchable ferroelectric component is negligible. In contrast, epitaxial strain and “negative pressure” can yield large, switchable polarizations that are compatible with the coexistence of magnetism, even in materials with no active ferroelectric ions.
Combinatorial approach to thin-film transistors using multicomponent semiconductor channels: An application to amorphous oxide semiconductors in In–Ga–Zn–O system
Authors: Iwasaki Tatsuya , Itagaki Naho , Den Tohru , Kumomi Hideya , Nomura Kenji , Kamiya Toshio , Hosono Hideo
Published: June 2007

A combinatorial approach was applied to thin-film transistors (TFTs) using amorphous In–Ga–Zn–O semiconductor channels. A large number of TFTs, having n-type channels with different chemical compositions, were fabricated simultaneously on a substrate. A systematic relation was clarified among the compositional ratio of In:Ga:Zn, oxygen partial pressure in film deposition atmosphere, and TFT characteristics. The results provide an experimental basis to understand the roles of each metallic element in the In–Ga–Zn–O system. This information leads to a guideline to tune the metallic compositions for required TFT specifications.
Cellular prion protein regulates β-secretase cleavage of the Alzheimer's amyloid precursor protein
Authors: Parkin Edward T. , Watt Nicole T. , Hussain Ishrut , Eckman Elizabeth A. , Eckman Christopher B. , Manson Jean C. , Baybutt Herbert N. , Turner Anthony J. , Hooper Nigel M.
Published: June 2007

Proteolytic processing of the amyloid precursor protein (APP) by β-secretase, β-site APP cleaving enzyme (BACE1), is the initial step in the production of the amyloid β (Aβ) peptide, which is involved in the pathogenesis of Alzheimer's disease. The normal cellular function of the prion protein (PrP
C
), the causative agent of the transmissible spongiform encephalopathies such as Creutzfeldt–Jakob disease in humans, remains enigmatic. Because both APP and PrP
C
are subject to proteolytic processing by the same zinc metalloproteases, we tested the involvement of PrP
C
in the proteolytic processing of APP. Cellular overexpression of PrP
C
inhibited the β-secretase cleavage of APP and reduced Aβ formation. Conversely, depletion of PrP
C
in mouse N2a cells by siRNA led to an increase in Aβ peptides secreted into the medium. In the brains of PrP knockout mice and in the brains from two strains of scrapie-infected mice, Aβ levels were significantly increased. Two mutants of PrP, PG14 and A116V, that are associated with familial human prion diseases failed to inhibit the β-secretase cleavage of APP. Using constructs of PrP, we show that this regulatory effect of PrP
C
on the β-secretase cleavage of APP required the localization of PrP
C
to cholesterol-rich lipid rafts and was mediated by the N-terminal polybasic region of PrP
C
via interaction with glycosaminoglycans. In conclusion, this is a mechanism by which the cellular production of the neurotoxic Aβ is regulated by PrP
C
and may have implications for both Alzheimer's and prion diseases.
Molecular mechanism of thioredoxin regulation in photosynthetic A
2
B
2
-glyceraldehyde-3-phosphate dehydrogenase
Authors: Fermani S. , Sparla F. , Falini G. , Martelli P. L. , Casadio R. , Pupillo P. , Ripamonti A. , Trost P.
Published: June 2007

Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a light-regulated, NAD(P)H-dependent enzyme involved in plant photosynthetic carbon reduction. Unlike lower photosynthetic organisms, which only contain A
4
–GAPDH, the major GAPDH isoform of land plants is made up of A and B subunits, the latter containing a C-terminal extension (CTE) with fundamental regulatory functions. Light-activation of AB–GAPDH depends on the redox state of a pair of cysteines of the CTE, which can form a disulfide bond under control of thioredoxin
f
, leading to specific inhibition of the NADPH-dependent activity. The tridimensional structure of A
2
B
2
–GAPDH from spinach chloroplasts, crystallized in the oxidized state, shows that each disulfide-containing CTE is docked into a deep cleft between a pair of A and B subunits. The structure of the CTE was derived from crystallographic data and computational modeling and confirmed by site-specific mutagenesis. Structural analysis of oxidized A
2
B
2
–GAPDH and chimeric mutant [A+CTE]
4
–GAPDH revealed that Arg-77, which is essential for coenzyme specificity and high NADPH-dependent activity, fails to interact with NADP in these kinetically inhibited GAPDH tetramers and is attracted instead by negative residues of oxidized CTE. Other subtle changes in catalytic domains and overall conformation of the tetramers were noticed in oxidized A
2
B
2
–GAPDH and [A+CTE]
4
–GAPDH, compared with fully active A
4
–GAPDH. The CTE is envisioned as a redox-sensitive regulatory domain that can force AB–GAPDH into a kinetically inhibited conformation under oxidizing conditions, which also occur during dark inactivation of the enzyme
in vivo
.
A βPix–Pak2a signaling pathway regulates cerebral vascular stability in zebrafish
Authors: Liu Jing , Fraser Sherri D. , Faloon Patrick W. , Rollins Evvi Lynn , Vom Berg Johannes , Starovic-Subota Olivera , Laliberte Angie L. , Chen Jau-Nian , Serluca Fabrizio C. , Childs Sarah J.
Published: June 2007

The vasculature tailors to the needs of different tissues and organs. Molecular, structural, and functional specializations are observed in different vascular beds, but few genetic models give insight into how these differences arise. We identify a unique cerebrovascular mutation in the zebrafish affecting the integrity of blood vessels supplying the brain. The zebrafishbubblehead(bbh) mutant exhibits hydrocephalus and severe cranial hemorrhage during early embryogenesis, whereas blood vessels in other regions of the embryo appear intact. Here we show that hemorrhages are associated with poor cerebral endothelial–mesenchymal contacts and an immature vascular pattern in the head. Positional cloning of bbh reveals a hypomorphic mutation in βPix, a binding partner for the p21-activated kinase (Pak) and a guanine nucleotide exchange factor for Rac and Cdc42. βPix is broadly expressed during embryonic development and is enriched in the brain and in large blood vessels. By knockdown of specific βPix splice variants, we show that they play unique roles in embryonic vascular stabilization or hydrocephalus. Finally, we show that Pak2a signaling is downstream of βPix. These data identify an essentialin vivorole for βPix and Pak2a during embryonic development and illuminate a previously unrecognized pathway specifically involved in cerebrovascular stabilization.
Coevolution between harmful male genitalia and female resistance in seed beetles
Authors: Rönn Johanna , Katvala Mari , Arnqvist Göran
Published: June 2007

Reproductive conflict between the sexes is thought to be a key force in the evolution of many reproductive characters, but persuasive evidence for its significance is still scarce. The spectacular evolution of male genitalia that impose physical injury on females during mating has often been suggested to be a product of sexually antagonistic coevolution, but our understanding of these extraordinary adaptations is very limited, and there are no direct data addressing their evolutionary elaboration. We show that more spiny male genitalia causes more harm to females during copulation and provide comparative evidence for the correlated evolution between these antagonistic adaptations in males and a female counteradaptation (the amount of connective tissue in the copulatory duct) in a group of insects. By combining comparative and experimental methods, we demonstrate that imbalance of relative armament of the sexes affects evolution of the economics of reproduction: as males evolve genitalia that are more harmful relative to the level of female counteradaptation, costs associated with mating for females increase and population fitness is depressed. Our results unveil a coevolutionary arms race between the sexes and are consistent with a proposed link between sexual conflict, species' viability, and the risk of extinction.
Labor force participation and human capital increases in an aging population and implications for U.S. research investment
Authors: Manton Kenneth G. , Lowrimore Gene R. , Ullian Arthur D. , Gu XiLiang , Tolley H. Dennis
Published: June 2007

The proportion of the United States labor force ≥65 years of age is projected to increase between 2004 and 2014 by the passing of age 65 of the large post-World War II baby boom cohorts starting in 2010 and their greater longevity, income, education, and health [Toossi M (2005)
Mon Labor Rev
128(11):25–44]. The aging of the U.S. labor force will continue to at least 2034, when the largest of the baby boom cohorts reaches age 70. Thus, the average health and functional capacity of persons age 65+ must improve for sufficient numbers of elderly persons to be physically and cognitively capable of work. This will require greater investments in research, public health, and health care. We examine how disability declines and improved health may increase human capital at later ages and stimulate the growth of gross domestic product and national wealth.
Interleukin 1 receptor antagonist mediates the antiinflammatory and antifibrotic effect of mesenchymal stem cells during lung injury
Authors: Ortiz Luis A. , DuTreil Maria , Fattman Cheryl , Pandey Amitabh C. , Torres German , Go Kristina , Phinney Donald G.
Published: June 2007

Mesenchymal stem cells (MSCs) have been exploited as cellular vectors to treat a wide array of diseases but the mechanisms responsible for their therapeutic effect remain indeterminate. Previously, we reported that MSCs inhibit bleomycin (BLM)-induced inflammation and fibrosis within the lungs of mice. Interrogation of the MSC transcriptome identified interleukin 1 receptor antagonist (IL1RN) as a potential mediator of this effect. Fractionation studies indicated that MSCs are the principal source of IL1RN in murine bone marrow and that its expression is restricted to a unique subpopulation of cells. Moreover, MSC-conditioned media was shown to block proliferation of an IL-1α-dependent T cell line and inhibit production of TNF-α by activated macrophages
in vitro
. Studies conducted in mice revealed that MSC administration was more effective than recombinant IL1RN delivered via adenoviral infection or osmotic pumps in inhibiting BLM-induced increases in TNF-α, IL-1α, and IL1RN mRNA in lung, IL1RN protein in bronchoalveolar lavage (BAL) fluid, and trafficking of lymphocytes and neutrophils into the lung. Therefore, MSCs protect lung tissue from BLM-induced injury by blocking TNF-α and IL-1, two fundamental proinflammatory cytokines in lung. Identification of IL1RN-expressing human MSC subpopulations may provide a novel cellular vector for treating chronic inflammatory diseases in humans.
Freshwater fishes of Patagonia in the 21st Century after a hundred years of human settlement, species introductions, and environmental change
Authors: Pascual Miguel A. , Cussac Víctor , Dyer Brian , Soto Doris , Vigliano Pablo , Ortubay Silvia , Macchi Patricio
Published: June 2007

We review the status of the freshwater fish fauna of Patagonia, an assemblage with 26 native species, comprising fishes of Gondwanan origin, marine dispersants, and oceanic elements of local origin. Several processes, old and new, have shaped the landscape of Patagonia and its fauna: a Gondwanan heritage, the Andes uplifting, Pleistocene ice, volcanic activity, introduction of exotic fishes, mostly Salmonids, and climate change. While there is a significant tradition of taxonomic work on native fish species, research on life history, trophic relationships, and community structure has started to emerge only in the last 15 years. Most studies were conducted in oligotrophic lakes of the Andes; while fauna of streams remains poorly observed. While documentation of impacts by salmonids is scarce, there is some compelling evidence indicating that freshwater communities have been significantly shaped by exotic fish. Impacts by exotic species appear to be dependent on temperature on the east side of the Andes, and land use and watershed perturbation on the west side.

In general, freshwater habitat conditions and how they affect fishes are poorly studied. In lakes, habitat complexity and its specialized use by native fishes may have ameliorated the impact by introduced salmonids. Although impacts on rivers abound, led by dam construction, the relationship between stream habitat integrity and native species health is still poorly understood. The future of freshwater resources will largely depend on how able we are to inform managers, the general public and colleagues about their value and the costs of not taking action. But current research capacity is insufficient to deal with most demands because of limitations in people, resources and baseline information. To support our claims, we need to promote regional assessments of freshwater resources and of major threats to their integrity, the building blocks of a regional agenda for their sustainable use.
A Proteomic Approach for the Diagnosis of ‘Oketsu’ (blood stasis), a Pathophysiologic Concept of Japanese Traditional (Kampo) Medicine
Authors: Matsumoto Chinami , Kojima Tetsuko , Ogawa Kazuo , Kamegai Satoshi , Oyama Takuya , Shibagaki Yukari , Kawasaki Tetsuo , Fujinaga Hiroshi , Takahashi Kozo , Hikiami Hiroaki , Goto Hirozo , Kiga Chizuru , Koizumi Keiichi , Sakurai Hiroaki , Muramoto Hiroshi , Shimada Yutaka , Yamamoto Masahiro , Terasawa Katsutoshi , Takeda Shuichi , Saiki Ikuo
Published: June 2007

‘Oketsu’ is a pathophysiologic concept in Japanese traditional (Kampo) medicine, primarily denoting blood stasis/stagnant syndrome. Here we have explored plasma protein biomarkers and/or diagnostic algorithms for ‘Oketsu’. Sixteen rheumatoid arthritis (RA) patients were treated with keishibukuryogan (KBG), a representative Kampo medicine for improving ‘Oketsu’. Plasma samples were diagnosed as either having an ‘Oketsu’ (n = 19) or ‘non‐Oketsu’ (n = 29) state according to Terasawa′s ‘Oketsu’ scoring system. Protein profiles were obtained by surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry (SELDI‐TOF MS) and hierarchical clustering and decision tree analyses were performed. KBG treatment for 4 or 12 weeks decreased the ‘Oketsu’ scores significantly. SELDI protein profiles gave 266 protein peaks, whose expression was significantly different between the ‘Oketsu’ and ‘non‐Oketsu’ states. Hierarchical clustering gave three major clusters (I, II, III). The majority (68.4%) of ‘Oketsu’ samples were clustered into one cluster as the principal component of cluster I. The remaining ‘Oketsu’ profiles constituted a minor component of cluster II and were all derived from patients cured of the ‘Oketsu’ state at 12 weeks. Construction of the decision tree addressed the possibility of developing a diagnostic algorithm for ‘Oketsu’. A reduction in measurement/pre‐processing conditions (from 55 to 16) gave a similar outcome in the clustering and decision tree analyses. The present study suggests that the pathophysiologic concept of Kampo medicine ‘Oketsu’ has a physical basis in terms of the profile of blood proteins. It may be possible to establish a set of objective criteria for diagnosing ‘Oketsu’ using a combination of proteomic and bioinformatics‐based classification methods.
Use of Resistant Peanut Cultivars and Reduced Fungicide Inputs for Disease Management in Strip-Tillage and Conventional Tillage Systems
Authors: Monfort W. S. , Culbreath A. K. , Stevenson K. L. , Brenneman T. B. , Perry C. D.
Published: June 2007

Field experiments were conducted in 2000 and 2001 to determine the effects of the number of fungicide applications and resistant cultivars on early leaf spot (Cercospora arachidicola) of peanut (Arachis hypogaea) grown in strip-tillage versus conventional tillage. Split-plot experiments with four replications of cultivars and fungicide treatments were conducted in commercial fields using strip-tillage and conventional-tillage practices in Worth Co., GA. Main treatments consisted of cultivars Georgia Green and Florida MDR-98 in both years with the addition of C-99R in 2001. Sub-plot treatments were two fungicide treatments: (i) azoxystrobin (AZO) 0.33 kg/ha (sprays 3 and 5) and chlorothalonil (CHL) 1.26 kg/ha (all other sprays), applied at 14-day intervals; and (ii) AZO 0.33 kg/ha (sprays 2 and 4) and CHL 1.26 kg/ha (all other sprays), applied at 21- to 28-day intervals. Leaf spot ratings were 2.3 and 4.4 for Georgia Green and 1.9 and 3.3 for Florida MDR-98 (LSD = 0.4) for treatments 1 and 2, respectively, in conventional-tillage plots, and 2.1 and 2.9 for Georgia Green and 2.3 and 1.7 for Florida MDR (LSD = 0.2) in strip-tillage plots, respectively, in 2001. Lower levels of leaf spot severity in large strip-tilled plots of resistant cultivars were similar to results observed in small plot experiments. Leaf spot control in reduced fungicide regimes in strip-till was comparable to leaf spot control in the standard 14-day fungicide regimes. Thus, strip-tillage may reduce fungicide requirements for leaf spot control on Georgia Green, and should allow for even better leaf spot control when combined with resistant cultivars such as Florida MDR-98 or C-99R. Utilization of precision agriculture technologies aided in visualizing and explaining some of treatment differences for leaf spot, stem rot, tomato spotted wilt, and yield in 2000 and 2001.

Accepted for publication 23 February 2007. Published 14 June 2007.
Seasonal Changes in Sleep Duration in African American and African College Students Living In Washington, D.C.
Authors: Volkov Janna , Rohan Kelly J. , Yousufi Samina M. , Nguyen Minh-Chau , Jackson Michael A. , Thrower Courtney M. , Stiller John W. , Postolache Teodor T.
Published: June 2007

Duration of nocturnal melatonin secretion, a marker of “biological night” that relates to sleep duration, is longer in winter than in summer in patients with seasonal affective disorder (SAD), but not in healthy controls. In this study of African and African American college students, we hypothesized that students who met criteria for winter SAD or subsyndromal SAD (S-SAD) would report sleeping longer in winter than in summer. In addition, based on our previous observation that Africans report more “problems” with change in seasons than African Americans, we expected that the seasonal changes in sleep duration would be greater in African students than in African American students. Based on Seasonal Pattern Assessment Questionnaire (SPAQ) responses, African American and African college students in Washington, D.C. (N = 575) were grouped into a winter SAD/S-SAD group or a no winter diagnosis group, and winter and summer sleep length were determined. We conducted a 2 (season) × 2 (sex) × 2 (ethnicity) × 2 (winter diagnosis group) ANCOVA on reported sleep duration, controlling for age. Contrary to our hypothesis, we found that African and African American students with winter SAD/S-SAD report sleeping longer in the summer than in the winter. No differences in seasonality of sleep were found between African and African American students. Students with winter SAD or S-SAD may need to sacrifice sleep duration in the winter, when their academic functioning/efficiency may be impaired by syndromal or subsyndromal depression, in order to meet seasonally increased academic demands.
Routine Multimodal Antiemesis Including Low-Dose Perphenazine in an Ambulatory Surgery Unit of a University Hospital: A 10-Year History
Authors: Williams Brian A. , Kentor Michael L. , Skledar Susan J. , Orebaugh Steven L. , Vallejo Manuel C.
Published: June 2007

For 10 years, we have used intravenous and oral perphenazine as part of a multimodal antiemetic prophylaxis care plan for at least 10,000 outpatients. We have never encountered an adverse event, to our knowledge, when the intravenous dose was less than or equal to 2 mg, or when the single preoperative oral dose did not exceed 8 mg (with no repeated dosing). As a single-dose component of multimodal antiemetic prophylaxis therapy, we believe that this track record of anecdotal safety in adults who meet certain criteria (age 14–70, no less than 45 kg, no history of extrapyramidal reactions or of Parkinson disease, and no Class III antidysrhythmic coadministered for coexisting disease) constitutes a sufficient patient safety basis for formal prospective study. We believe that future perphenazine studies should include routine coadministration with prospectively established multimodal antiemetics (i.e., dexamethasone and a 5-HT3antagonist). In settings where droperidol is still routinely used and deemed acceptable by local scientific ethics committees, we believe that oral perphenazine 8 mg should be compared head to head with droperidol 0.625–1.25 mg in patients receiving coadministered dexamethasone and 5-HT3antagonists in order to determine differences in synergistic efficacy, if any. Similar trials should be performed, individually evaluating cyclizine, transdermal scopolamine, and aprepitant in combination with coadministered dexamethasone and a 5-HT3antagonist. Such studies should also quantify efficacy in preventing nausea and vomiting after discharge home, and also quantify the extent to which the prophylaxis plans reduce postanesthesia care unit (PACU) requirements (i.e., increase PACU bypass), reduce the need for any nursing interventions for postoperative nausea and/or vomiting (PONV), and influence the extent to which any variable costs of postoperative nursing care are reduced.
Bilateral Segmental Testicular Infarction
Authors: Bayne Aaron , Koslin Brad , Daneshmand Siamak
Published: June 2007

Segmental testicular infarction is a rare entity with fewer than 40 cases documented in the literature. It frequently mimics an acute scrotum presenting with pain and swelling. Difficulty distinguishing benign from malignant lesions on imaging has led to radical orchiectomy in the past. With improvements in imaging, this condition may be treated more conservatively. We present the first case of bilateral segmental testicular infarction and discuss management options.
Hemorrhagic Complications of Minimally Invasive Urological Surgeries, Treated with Selective Endovascular Embolization
Authors: Halachmi Sarel , Ofer Amos , Gershin Eduard , Engel Ahuva , Meretyk Shimon
Published: June 2007

Minimally invasive urological procedures have gained in popularity and replaced open surgery in various urological procedures. Although considered minimally invasive, these procedures are not free from complications, and life-threatening hemorrhage may occur. Herein we describe 3 case series of patients who underwent minimally invasive urological surgeries that were complicated with bleeding. In all 3 patients we used super selective angiographic embolization to stop hemorrhage. Minimally invasive urological surgeries carry the risk of hemorrhage, and patients should be informed about this possibility. In hemodynnmic stable patients endovascular embolization allowed bleeding cessation with maximal preservation of the bleeding kidney tissue.
Ultrastructural Study of an Atypical Case of Infertility
Authors: Sánchez Sánchez Ernesto , Mardomingo Carmen Tejedor
Published: June 2007

An atypical case of infertility associated with severe sperm abnormalities is presented. A 29-year-old man with 4 years of primary infertility had no history of significant illness, and no hereditary pathology or male infertility existed in his family. Physical examination of the patient showed no pathological findings. The analyses of four semen samples showed: sperm count, 67-83 106/ml; 0% motility. The morphological analysis showed absence of flagellum, 14-16%; short-tail spermatozoa, 45-64%; coiled tails, 12-17%; and an abnormal proportion of spermatids and spermatocytes. Normal spermatozoa were found in 11-16%. Endocrine profile was found within the normal range. Testicular biopsy revealed impaired spermatogenesis. Scanning electron microscopy revealed sperm heads with intact nuclei and acrosomal regions. To our surprise, some of the stunted tails were uniflagellate. To our knowledge, this is a very uncommon case of sperm tail defect.
Torsion of an Encysted Fluid Collection
Authors: Senayli Atilla , Senayli Yesim , Sezer Engin , Sezer Taner
Published: June 2007

Torsion of a cyst within the tunica vaginalis is a rare entity and clinical course can easily be confused with other diseases that cause acute scrotum. We report a 6-year-old child with 3 days of acute scrotum findings. Patient had surgery with the suspicion of testis torsion. Torsion of a cyst within the tunica vaginalis was found intraoperatively. In pathologic evaluation, a necrotic funicular cyst was diagnosed. Two different mechanisms were reported for the reason of this disease: hernia sac protrusion in the hydrocele sac and bell-clapper deformity. Our observations were on the side of bell-clapper deformity. We aimed to share our findings with this report.
Laparoscopic Radical Nephrectomy: The New Gold Standard Surgical Treatment for Localized Renal Cell Carcinoma
Authors: Eskicorapci Saadettin Yilmaz , Teber Dogu , Schulze Michael , Ates Mutlu , Stock Christian , Rassweiler Jens J.
Published: June 2007

We will try to demonstrate that laparoscopic radical nephrectomy could be the new gold standard treatment for renal cell carcinoma with the aid of the current reports exploring the advantages and disadvantages of laparoscopic radical nephrectom overopen surgery.

Reported perioperative outcomes like operating time, blood loss, postoperative analgesia requirement, and length of hospital stay and duration of convalescence had been found to be in favor of laparoscopic radical nephrectomy. Some technical issues like approach of laparoscopic technique (Transperitoneal versus retroperitoneal laparoscopic nephrectomy), removal of dissected specimen and need for lymph node dissection had been also discussed in detail in this review. Besides, oncological safety of laparoscopic radical nephrectomy had been explored. The overall five-year disease free survival rates of laparoscopic radical nephrectomy in recent series were found to be over 90%. All of the series including the present one at least confirmed the oncological efficacy of LRN as compared with open surgical approach.

The contemporary review of the literature documents clearly demonstrated the perioperative benefits of laparoscopy compared to the open approach. Nevertheless, the development, however, more safe and reliable technique in laparoscopy is necessary for tumor extraction. Recent studies confirmed the long-term similar cancer control results of laparoscopic radical nephrectomy with open surgery. Despite some technical modifications by the different groups, it can be stated that laparoscopic radical nephrectomy is the new gold standard treatment modality for patients with localized renal cell carcinoma.
Cytokine-Based Immunotherapy for Advanced Kidney Cancer: Past Results and Future Perspectives in the Era of Molecularly Targeted Agents
Authors: Porta Camillo , Paglino Chiara , Imarisio Ilaria , Bonomi Lucia
Published: June 2007

Until recently, immunotherapy has been the only therapeutic option available for patients with advanced kidney cancer, even though different choices were often made on the two sides of the Atlantic Ocean. The absence of alternatives made different immunotherapeutic approaches common practice, even with few adequate randomized studies that addressed key questions, such as the best treatment and schedule, and so on. The recent registration of the first two, molecularly targeted, agents Sorafenib and Sunitinib could (and will) render many therapeutic approaches, e.g., single-agent Interferon, obsolete. In this review, we shall cover the past achievements obtained so far with cytokine-based immunotherapy and discuss the present role of immunotherapy in the era of molecularly targeted agents. In particular, specific indications for immunotherapy are emerging (e.g., the use of Interleukin-2 in patients with high CAIX expression), while new trials are ongoing to test immunotherapy in combination with molecularly targeted agents, such as Sorafenib, Sunitinib, or Bevacizumab.
Colonic Carcinoma Masquerading as Scrotal Swelling: A Case Report and Review of Literature
Authors: Paravastu Sharath C. V. , Batra Meenakshi , Ananthakrishnan Krishnan
Published: June 2007

Tumours of the spermatic cord are rare. Most tumours of the spermatic cord are metastatic and are typically an incidental finding at orchidectomy for other pathology. Primary pathology is usually from the gastrointestinal tract. We report a very rare presentation of an asymptomatic gastrointestinal tumour as a spermatic cord mass.

male patient presented with a painless scrotal swelling. Radical orchidectomy revealed an adenocarcinoma in the spermatic cord. Further investigations disclosed an adenocarcinoma of the descending colon, metastasing to the spermatic cord that gave a false notion of a scrotal swelling secondary to infection. This unusual situation reminds us that spermatic cord metastases are rare. In the event of nonresponding scrotal swelling to antibiotics, further investigations would be prudent, whilst awaiting the definitive pathology report from the radical orchidectomy.
The Role of Surveillance in the Management of Small Renal Masses
Authors: Volpe Alessandro
Published: June 2007

Incidentally detected, small renal masses (SRMs) have been increasing significantly in recent years due to the widespread use of improved cross-sectional imaging. A significant number of incidental SRMs are diagnosed in elderly patients who are more likely to undergo imaging for other medical issues. The natural history of SRMs has not been historically well understood because most masses are surgically removed soon after diagnosis.

Several reports of surveillance of SRMs have been published in the last few years. When followed conservatively with serial imaging, SRMs have variable growth rates with an average of 0.28 cm/year, according to a recent meta-analysis. Larger series with longer follow-up are needed, but a significant number of small tumors seem to have an indolent behavior with a slow growth rate and a limited tendency to progress. The standard of care for enhancing SRMs is surgery. Up to one-third of surgically removed, <4-cm tumors are histologically benign. The outcomes of current surgical treatment of histologically confirmed, <4-cm, renal cell carcinomas are excellent, but this has not led to a decrease in mortality. Based on these considerations and on the available data on the natural history of SRMs, it seems reasonable to consider that we may be overtreating these lesions. This is especially true for elderly or unfit patients who have a decreased life expectancy. In these selected patients and in patients who refuse active treatment, it seems reasonable to propose an initial period of active surveillance for incidental SRMs, with delayed intervention for those tumors that will exhibit fast growth during follow-up. Percutaneous needle biopsies of renal tumors can be safely performed with the use of modern techniques and have the potential to characterize SRMs at histologically diagnosis, thereby allowing a better selection of the conservative or active treatment that is best suited for each individual patient.
Urothelial Carcinoma of the Bladder Metastatic to Bone Marrow Presenting as Isolated Thrombocytopenia
Authors: Chan Robert C. , Hundemer Greg L. , Tatsas Amy , Cookson Michael S.
Published: June 2007

The skeletal system is a frequent site for metastases of urothelial carcinoma (UC) of the bladder (22–37%). Of those cases involving bone, the marrow is infiltrated in 27% of patients. Imaging modalities, such as X-ray and CT, will detect gross skeletal lesions in the vast majority of these patients with bone marrow involvement, however, most patients with bone involvement are symptomatic at presentation. Additionally, there have been few reports in the literature of bone marrow metastases from UC presenting with isolated thrombocytopenia.

This case report describes the case of a 53-year-old male with muscle-invasive transitional cell carcinoma of the bladder treated with cystoprostatectomy. Preoperative evaluation was significant only for mild thrombocytopenia. Standard workup for metastatic bony involvement, which included history, physical, chest X-ray, and whole body CT, was negative. Postoperatively, the patient's thrombocytopenia worsened and he bled diffusely from his pelvic bed. Bone marrow biopsy was obtained and showed the entire marrow cavity to be filled with metastatic transitional cells.

In the event of a similar future presentation of isolated thrombocytopenia in the setting of invasive UC, the clinician should consider a bone marrow biopsy, in addition to the standard workup for metastatic bony involvement, prior to proceeding with any surgical intervention.
Not to Knot a Catheter. Case Report of the Knotting of a Suprapubic Catheter
Authors: Farook S. A. , Kariholu U. , Kousidis G. , Powlis M.
Published: June 2007

A 20-month-old boy, who underwent left nephrectomy, had a suprapubic catheter inserted that knotted within the bladder. This case report identifies possible causes for such occurrences and how best to manage them.
Assistive Technology and Supplementary Treatment for Individuals with Rett Syndrome
Authors: Lotan Meir
Published: June 2007

Rett syndrome (RS) is a neurological disorder, affecting mainly females, caused by MECP2 mutations usually resulting in severe physical disability. Due to the physical challenges faced by the individual with RS and her family, her rehabilitation program should support her throughout different daily activities, contexts, and surroundings. Rehabilitation interventions to reverse physical impairments include exercise of various types and different physical modalities. Nevertheless, in the vast majority of cases, hands-on therapeutic intervention opportunities are available for the client through a minute part of her waking hours. Hence, a supplementary system is required in order to engulf the child with a comprehensive network of support. Supplementary intervention can support physical impairment by introducing adaptive techniques, environmental modifications, and assistive technologies. The therapy program of an individual with RS should include the use of assistive technology when such devices improve the user's performance. The term “supplementary management” relates to the fact that this intervention may be performed by nonprofessionals with the supervision of a qualified therapist. Such an intervention can further support the therapeutic goals of the child, at a time when direct intervention is not supplied. The present article will review the available literature on the topic of assistive technology, incorporating the clinical knowledge of the author in the field of RS.
RNAi-dependent H3K27 methylation is required for heterochromatin formation and DNA elimination in Tetrahymena
Authors: Liu Yifan , Taverna Sean D. , Muratore Tara L. , Shabanowitz Jeffrey , Hunt Donald F. , Allis C. David
Published: June 2007

Methylated H3K27 is an important mark for Polycomb group (PcG) protein-mediated transcriptional gene silencing (TGS) in multicellular eukaryotes. Here a Drosophila E(z) homolog, EZL1, is characterized in the ciliated protozoan Tetrahymena thermophila and is shown to be responsible for H3K27 methylation associated with developmentally regulated heterochromatin formation and DNA elimination. Importantly, Ezl1p-catalyzed H3K27 methylation occurs in an RNA interference (RNAi)-dependent manner. H3K27 methylation also regulates H3K9 methylation in these processes. Furthermore, an “effector” of programmed DNA elimination, the chromodomain protein Pdd1p, is shown to bind both K27- and K9-methylated H3. These studies provide a framework for an RNAi-dependent, Polycomb group protein-mediated heterochromatin formation pathway in Tetrahymena and underscore the connection between the two highly conserved machineries in eukaryotes.